changelog

* migration and changelog

* missed valid root

* removing unneeded test, more optimization

* adding strict dependency

* linting

* fixing 1 more test

* bastin's suggestion

.bazelversion

@@ -1 +1 @@
-7.1.0
+7.4.1

.github/PULL_REQUEST_TEMPLATE.md

@@ -33,5 +33,5 @@ Fixes #
 **Acknowledgements**
 
 - [ ] I have read [CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
-- [ ] I have made an appropriate entry to [CHANGELOG.md](https://github.com/prysmaticlabs/prysm/blob/develop/CHANGELOG.md).
+- [ ] I have included a uniquely named [changelog fragment file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
 - [ ] I have added a description to this PR with sufficient context for reviewers to understand this PR.

.github/actions/gomodtidy/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.22-alpine
+FROM golang:1.24-alpine
 
 COPY entrypoint.sh /entrypoint.sh
 

.github/workflows/changelog.yml

@@ -1,33 +1,34 @@
-name: CI
+# This workflow will build a golang project
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
+
+name: changelog
 
 on:
   pull_request:
-    branches:
-      - develop
+    branches: [ "develop" ]
 
 jobs:
-  changed_files:
-    runs-on: ubuntu-latest 
-    name: Check CHANGELOG.md
+  run-changelog-check:
+    runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - name: changelog modified
-        id: changelog-modified
-        uses: tj-actions/changed-files@v45
-        with:
-          files: CHANGELOG.md
+      - name: Checkout source code
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
 
-      - name: List all changed files
+      - name: Download unclog binary
+        uses: dsaltares/fetch-gh-release-asset@aa2ab1243d6e0d5b405b973c89fa4d06a2d0fff7 # 1.1.2
+        with:
+          repo: OffchainLabs/unclog
+          version: "tags/v0.1.3"
+          file: "unclog"
+
+      - name: Get new changelog files
+        id: new-changelog-files
+        uses: OffchainLabs/gh-action-changed-files@9200e69727eb73eb060652b19946b8a2fdfb654b # v4.0.8
+        with:
+          files: |
+            changelog/**.md
+
+      - name: Run lint command
         env:
-          ALL_CHANGED_FILES: ${{ steps.changelog-modified.outputs.all_changed_files }}
-        run: |
-          if [[ ${ALL_CHANGED_FILES[*]} =~ (^|[[:space:]])"CHANGELOG.md"($|[[:space:]]) ]];
-          then
-            echo "CHANGELOG.md was modified.";
-            exit 0;
-          else
-            echo "CHANGELOG.md was not modified.";
-            echo "Please see CHANGELOG.md and follow the instructions to add your changes to that file."
-            echo "In some rare scenarios, a changelog entry is not required and this CI check can be ignored."
-            exit 1;
-          fi
+          ALL_ADDED_MARKDOWN: ${{ steps.new-changelog-files.outputs.added_files }}
+        run: chmod +x unclog && ./unclog check -fragment-env=ALL_ADDED_MARKDOWN

.github/workflows/clang-format.yml

@@ -0,0 +1,21 @@
+name: Protobuf Format
+
+on: 
+  push:
+    branches: [ '*' ]
+  pull_request:
+    branches: [ '*' ]
+  merge_group:
+    types: [checks_requested]
+
+jobs:
+  clang-format-checking:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      # Is this step failing for you? 
+      # Run: clang-format -i proto/**/*.proto
+      # See: https://clang.llvm.org/docs/ClangFormat.html
+      - uses: RafikFarhad/clang-format-github-action@v3
+        with:
+          sources: "proto/**/*.proto"

.github/workflows/fuzz.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:
-          go-version: '1.22.3'
+          go-version: '1.23.5'
       - id: list
         uses: shogo82148/actions-go-fuzz/list@v0
         with:
@@ -36,7 +36,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:
-          go-version: '1.22.3'
+          go-version: '1.23.5'
       - uses: shogo82148/actions-go-fuzz/run@v0
         with:
           packages: ${{ matrix.package }}

.github/workflows/go.yml

@@ -28,15 +28,15 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Set up Go 1.22
+      - name: Set up Go 1.24
         uses: actions/setup-go@v4
         with:
-          go-version: '1.22.6'
+          go-version: '1.24.0'
       - name: Run Gosec Security Scanner
         run: | # https://github.com/securego/gosec/issues/469
           export PATH=$PATH:$(go env GOPATH)/bin
-          go install github.com/securego/gosec/v2/cmd/gosec@v2.19.0
-          gosec -exclude-generated -exclude=G307 -exclude-dir=crypto/bls/herumi ./...
+          go install github.com/securego/gosec/v2/cmd/gosec@v2.22.1
+          gosec -exclude-generated -exclude=G307,G115 -exclude-dir=crypto/bls/herumi ./...
 
   lint:
     name: Lint
@@ -45,16 +45,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Set up Go 1.22
+      - name: Set up Go 1.24
         uses: actions/setup-go@v4
         with:
-          go-version: '1.22.6'
+          go-version: '1.24.0'
           id: go
 
       - name: Golangci-lint
         uses: golangci/golangci-lint-action@v5
         with:
-          version: v1.56.1
+          version: v1.64.5
           args: --config=.golangci.yml --out-${NO_FUTURE}format colored-line-number
 
   build:
@@ -64,7 +64,7 @@ jobs:
       - name: Set up Go 1.x
         uses: actions/setup-go@v4
         with:
-          go-version: '1.22.6'
+          go-version: '1.24.0'
         id: go
 
       - name: Check out code into the Go module directory

.golangci.yml

@@ -1,28 +1,20 @@
 run:
-  skip-files:
+  timeout: 10m
+  go: '1.23.5'
+
+issues:
+  exclude-files:
     - validator/web/site_data.go
     - .*_test.go
-  skip-dirs:
+  exclude-dirs:
     - proto
     - tools/analyzers
-  timeout: 10m
-  go: '1.22.6'
 
 linters:
   enable-all: true
   disable:
     # Deprecated linters:
-    - deadcode
-    - exhaustivestruct
-    - golint
     - govet
-    - ifshort
-    - interfacer
-    - maligned
-    - nosnakecase
-    - scopelint
-    - structcheck
-    - varcheck
 
     # Disabled for now:
     - asasalint
@@ -34,6 +26,8 @@ linters:
     - dogsled
     - dupl
     - durationcheck
+    - errname
+    - err113
     - exhaustive
     - exhaustruct
     - forbidigo
@@ -47,17 +41,17 @@ linters:
     - gocyclo
     - godot
     - godox
-    - goerr113
     - gofumpt
-    - gomnd
     - gomoddirectives
     - gosec
     - inamedparam
     - interfacebloat
+    - intrange
     - ireturn
     - lll
     - maintidx
     - makezero
+    - mnd
     - musttag
     - nakedret
     - nestif
@@ -72,6 +66,7 @@ linters:
     - predeclared
     - promlinter
     - protogetter
+    - recvcheck
     - revive
     - spancheck
     - staticcheck
@@ -80,6 +75,7 @@ linters:
     - tagliatelle
     - thelper
     - unparam
+    - usetesting
     - varnamelen
     - wrapcheck
     - wsl

BUILD.bazel

@@ -165,7 +165,7 @@ STATICCHECK_ANALYZERS = [
     "sa6006",
     "sa9001",
     "sa9002",
-    #"sa9003", # Doesn't build. See https://github.com/dominikh/go-tools/pull/1483
+    "sa9003",
     "sa9004",
     "sa9005",
     "sa9006",
@@ -197,6 +197,7 @@ nogo(
         "//tools/analyzers/logruswitherror:go_default_library",
         "//tools/analyzers/maligned:go_default_library",
         "//tools/analyzers/nop:go_default_library",
+        "//tools/analyzers/nopanic:go_default_library",
         "//tools/analyzers/properpermissions:go_default_library",
         "//tools/analyzers/recursivelock:go_default_library",
         "//tools/analyzers/shadowpredecl:go_default_library",

CHANGELOG.md

@@ -4,7 +4,291 @@ All notable changes to this project will be documented in this file.
 
 The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.
 
-## [Unreleased](https://github.com/prysmaticlabs/prysm/compare/v5.1.2...HEAD)
+## [v5.3.2](https://github.com/prysmaticlabs/prysm/compare/v5.3.1...v5.3.2) - 2025-03-25
+
+This release introduces support for the `Hoodi` testnet.
+
+Release highlights:
+
+- Ability to run the node on the `Hoodi` tesnet. See https://blog.ethereum.org/2025/03/18/hoodi-holesky for more information about `Hoodi`.
+- A new feature that allows treat certain blocks as invalid. This is especially useful when the network is split, allowing the node to discontinue following unwanted forks.
+
+Testnet operators are required to update to this release. Without this release you will be unable to run the node on the `Hoodi` testnet.
+
+Mainnet operators are recommended to update to this release at their regular cadence.
+
+### Added
+
+- enable SSZ for builder API calls. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14976)
+- Add Hoodi testnet flag `--hoodi` to specify Hoodi testnet config and bootnodes. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15057)
+- block_gossip topic support to the beacon api event stream. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15038)
+- Added a static analyzer to discourage use of panic() in Prysm. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15075)
+- Add a feature flag `--blacklist-roots` to allow the node to specify blocks that will be treated as invalid. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15030)
+
+### Changed
+
+- changed request object for `POST /eth/v1/beacon/states/head/validators` to omit the field if empty for satisfying other clients. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15031)
+- Update spec test to v1.5.0-beta.3. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15050)
+- Update Gossip and RPC message limits to comply with the spec. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14799)
+- Return 404 instead of 500 from API when when a blob for a requested index is not found. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14845)
+- Save Electra orphaned attestations into attestations pool's block attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15060)
+- Removed redundant string conversion in `BeaconDbStater.State` to improve code clarity and maintainability. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15081)
+
+### Fixed
+
+- Update seen unaggregated att cache to properly handle Electra attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15034)
+- cosmetic fix for calling `/prysm/validators/performance` when connecting to non prysm beacon nodes and removing the 404 error log. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15062)
+- Tracked validator cache: Make sure no to loose the reference. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15077)
+- Fixed proposing at genesis when starting post Bellatrix. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15084)
+
+## [v5.3.1](https://github.com/prysmaticlabs/prysm/compare/v5.3.0...v5.3.1) - 2025-03-13
+
+This release is packed with critical fixes for **Electra** and some important fixes for mainnet too. 
+
+The release highlights include:
+
+- Ensure that deleting a block from the database clears its entry in the slot->root db index. This issue was causing some operators to have a bricked database, requiring a full resync. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15011)
+- Updated go to go1.24.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- Added a feature flag to sync from an arbitrary beacon block root at startup. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15000)
+- Updated default gas limit from 30M to 36M. Override this with `--suggested-gas-limit=` in the validator client. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14858)
+
+Known issues in **Electra**:
+
+- Duplicate attestations are needlessly processed. This is being addressed in [[PR]](https://github.com/prysmaticlabs/prysm/pull/15034).
+
+Testnet operators are strongly encouraged to update to this release. There are many fixes and improvements from the Holesky upgrade incident.
+
+Mainnet operators are recommended to update to this release at their regular cadence. 
+
+### Added
+
+- enable E2E for minimal and mainnet tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14842)
+- enable web3signer E2E for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14936)
+- Enable multiclient E2E for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14946)
+- Enable Scenario E2E tests with electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14946)
+- Add endpoint for getting pending deposits. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14941)
+- Add request hash to header for builder: executable data to block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14955)
+- Log execution requests in each block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14956)
+- Add endpoint for getting pending partial withdrawals. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14949)
+- Tracked validators cache: Added the `ItemCount` method. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14957)
+- Tracked validators cache: Added the `Indices` method. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14957)
+- Added deposit request testing for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14964)
+- Added support for otel tracing transport in HTTP clients in Prysm. This allows for tracing headers to be sent with http requests such that spans between the validator and beacon chain can be connected in the tracing graph. This change does nothing without `--enable-tracing`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14972)
+- Add SSZ support to light client finality and optimistic APIs. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14836)
+- add log to committee index when committeebits are not the expected length of 1. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14993)
+- Add acceptable address types for static peers. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14886)
+- Added a feature flag to sync from an arbitrary beacon block root at startup. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15000)
+
+### Changed
+
+- updates geth to 1.15.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14842)
+- Updates blst to v3.14.0 and fixes the references in our deps.bzl file. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14921)
+- Updated tracing exporter from jaeger to otelhttp. This should not be a breaking change. Jaeger supports otel format, however you may need to update your URL as the default otel-collector port is 4318. See the [OpenTelemtry Protocol Exporter docs](https://opentelemetry.io/docs/specs/otel/protocol/exporter/) for more details. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14928)
+- Don't use MaxCover for Electra on-chain attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14925)
+- Tracked validators cache: Remove validators from the cache if not seen after 1 hour. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14957)
+- execution requests errors on ssz length have been improved. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14962)
+- deprecate beacon api endpoints based on [3.0.0 release](https://github.com/ethereum/beacon-APIs/pull/506) for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14967)
+- Use go-cmp for printing better diffs for assertions.DeepEqual. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14978)
+- Reorganized beacon chain flags in `--help` text into logical sections. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14959)
+- `--validators-registration-batch-size`: Change default value from `0` to `200`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14981)
+- Updated go to go1.24.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- Updated gosec to v2.22.1 and golangci to v1.64.5. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- Updated github.com/trailofbits/go-mutexasserts. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- Updated rules_go to cf3c3af34bd869b864f5f2b98e2f41c2b220d6c9 to support go1.24.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- Validate blob sidecar re-order signature and bad parent block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15013)
+- Updated default gas limit from 30M to 36M. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14858)
+- Ignore errors from `hasSeenBit` and don't pack unaggregated attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15018)
+
+### Removed
+
+- Remove Fulu state and block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14905)
+- Removed the log summarizing all started services. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14958)
+
+### Fixed
+
+- fixed max and target blob per block from static to dynamic values. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14911)
+- refactored publish block and block ssz functions to fix gocognit. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14913)
+- refactored publish blinded block and blinded block ssz to correctly deal with version headers and sent blocks. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14913)
+- Only check for electra related engine methods if electra is active. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14924)
+- Fixed bug that breaks new blob storage layout code on Windows, caused by accidental use of platform-dependent path parsing package. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14931)
+- Fix E2E Process Deposit Evaluator for Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14933)
+- Fixed the `bazel run //:gazelle` command in `DEPENDENCIES.md`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14934)
+- Fix E2E Deposit Activation Evaluator for Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14938)
+- Dedicated processing of `SingleAttestation` in the monitor service. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14965)
+- adding in content type and accept headers for builder API call on registration. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14961)
+- fixed gocognit in block conversions between json and proto types. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14953)
+- Lint: Fix violations of S1009: should omit nil check; len() for nil slices is defined as zero. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14973)
+- Lint: Fix violations of non-constant format string in call. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14974)
+- Fixed violations of gosec G301. This is a check that created files and directories have file permissions 0750 and 0600 respectively. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14980)
+- Check for the correct attester slashing type during gossip validation. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14985)
+- cosmetic fix for post electra validator logs displaying attestation committee information correctly. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14992)
+- fix inserting the wrong committee index into the seen cache for electra attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14998)
+- Allow any block type to be unmarshaled rather than only phase0 blocks in `slotByBlockRoot`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15008)
+- Fixed pruner to not block while pruning large database by introducing batchSize. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14929)
+- Decompose Electra block attestations to prevent redundant packing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14896)
+- Fixed use of deprecated rand.Seed. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- Fixed build issue with SszGen where the go binary was not present in the $PATH. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14969)
+- fixed /eth/v1/config/spec displays BLOB_SIDECAR_SUBNET_COUNT,BLOB_SIDECAR_SUBNET_COUNT_ELECTRA. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15016)
+- Ensure that deleting a block from the database clears its entry in the slot->root db index. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15011)
+- Broadcasting BLS to execution changes should not use the request context in a go routine. Use context.Background() for the broadcasting go routine. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15019)
+- /eth/v1/validator/sync_committee_contribution should check for optimistic status and return a 503 if it's optimistic. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15022)
+- Fixes printing superfluous response.WriteHeader call from error in builder. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15025)
+- Fixes e2e run with builder having wrong gaslimit header due to not being set on eth1 nodes. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15025)
+- Fixed a bug in the event stream handler when processing payload attribute events where the timestamp and slot of the event would be based on the head rather than the current slot. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14963)
+- Handle unaggregated attestations when decomposing Electra block attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15027)
+
+## [v5.3.0](https://github.com/prysmaticlabs/prysm/compare/v5.2.0...v5.3.0) - 2025-02-12
+
+This release includes support for Pectra activation in the [Holesky](https://github.com/eth-clients/holesky) and [Sepolia](https://github.com/eth-clients/sepolia) testnets! The release contains many fixes for Electra that have been found in rigorous testing through devnets in the last few months.
+
+For mainnet, we have a few nice features for you to try:
+
+- [PR #14023](https://github.com/prysmaticlabs/prysm/pull/14023) introduces a new file layout structure for storing blobs. Rather than storing all blob root directories in one parent directory, blob root directories are organized in subdirectories by epoch. This should vastly decrease the blob cache warmup time when Prysm is starting. Try this feature with `--blob-storage-layout=by-epoch`.
+
+Updating to this release is **required** for Holesky and Sepolia operators and it is **recommended** for mainnet users as there are a few bug fixes that apply to deneb logic.
+
+### Added
+
+- Added an error field to log `Finished building block`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14696)
+- Implemented a new `EmptyExecutionPayloadHeader` function. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14713)
+- Added proper gas limit check for header from the builder. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14707)
+- `Finished building block`: Display error only if not nil. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14722)
+- Added light client feature flag check to RPC handlers. [PR](https://github.com/prysmaticlabs/prysm/pull/14736). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14782)
+- Added support to update target and max blob count to different values per hard fork config. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14678)
+- Log before blob filesystem cache warm-up. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14735)
+- New design for the attestation pool. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14324)
+- Add field param placeholder for Electra blob target and max to pass spec tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14733)
+- Light client: Add better error handling. [PR](https://github.com/prysmaticlabs/prysm/pull/14749). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14782)
+- Add EIP-7691: Blob throughput increase. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14750)
+- Trace IDONTWANT Messages in Pubsub. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14778)
+- Add Fulu fork boilerplate. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14771)
+- DB optimization for saving light client bootstraps (save unique sync committees only). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14782)
+- Separate type for unaggregated network attestations. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14659)
+- Remote signer electra fork support. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14477)
+- Add Electra test case to rewards API. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14816)
+- Update `proto_test.go` to Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14817)
+- Update slasher service to Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14812)
+- Builder API endpoint to support Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14344)
+- Added protoc toolchains with a version of v25.3. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14818)
+- Add test cases for the eth_lightclient_bootstrap API SSZ support. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14824)
+- Handle `AttesterSlashingElectra` everywhere in the codebase. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14823)
+- Add Beacon DB pruning service to prune historical data older than MIN_EPOCHS_FOR_BLOCK_REQUESTS (roughly equivalent to the weak subjectivity period). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14687)
+- Nil consolidation request check for core processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14851)
+- Updated blob sidecar api endpoint for Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14852)
+- Slashing pool service to convert slashings from Phase0 to Electra at the fork. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14844)
+- check to stop eth1 voting after electra and eth1 deposits stop. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14835)
+- WARN log message on node startup advising of the upcoming deprecation of the --enable-historical-state-representation feature flag. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14856)
+- Beacon API event support for `SingleAttestation` and `SignedAggregateAttestationAndProofElectra`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14855)
+- Added Electra tests for `TestLightClient_NewLightClientOptimisticUpdateFromBeaconState` and `TestLightClient_NewLightClientFinalityUpdateFromBeaconState`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14783)
+- New option to select an alternate blob storage layout. Rather than a flat directory with a subdir for each block root, a multi-level scheme is used to organize blobs by epoch/slot/root, enabling leaner syscalls, indexing and pruning. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14023)
+- Send pending att queue's attestations through the notification feed. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14862)
+- Prune all pending deposits and proofs in post-Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14829)
+- Add Pectra testnet dates. (Sepolia and Holesky). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14884)
+
+### Changed
+
+- Process light client finality updates only for new finalized epochs instead of doing it for every block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14713)
+- Refactor subnets subscriptions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14711)
+- Refactor RPC handlers subscriptions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14732)
+- Go deps upgrade, from `ioutil` to `io`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14737)
+- Move successfully registered validator(s) on builder log to debug. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14735)
+- Update some test files to use `crypto/rand` instead of `math/rand`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14747)
+- Re-organize the content of the `*.proto` files (No functional change). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14755)
+- SSZ files generation: Remove the `// Hash: ...` header.[[PR]](https://github.com/prysmaticlabs/prysm/pull/14760)
+- Updated Electra spec definition for `process_epoch`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14768)
+- Update our `go-libp2p-pubsub` dependency. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14770)
+- Re-organize the content of files to ease the creation of a new fork boilerplate. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14761)
+- Updated spec definition electra `process_registry_updates`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14767)
+- Fixed Metadata errors for peers connected via QUIC. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14776)
+- Updated spec definitions for `process_slashings` in godocs. Simplified `ProcessSlashings` API. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14766)
+- Update spec tests to v1.5.0-beta.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14788)
+- Process light client finality updates only for new finalized epochs instead of doing it for every block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14718)
+- Update blobs by rpc topics from V2 to V1. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14785)
+- Updated geth to 1.14~. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14351)
+- E2e tests start from bellatrix. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14351)
+- Version pinning unclog after making some ux improvements. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14802)
+- Remove helpers to check for execution/compounding withdrawal credentials and expose them as methods. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14808)
+- Refactor `2006-01-02 15:04:05` to `time.DateTime`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14792)
+- Updated Prysm to Go v1.23.5. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14818)
+- Updated Bazel version to v7.4.1. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14818)
+- Updated rules_go to v0.46.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14818)
+- Updated golang.org/x/tools to be compatible with v1.23.5. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14818)
+- CI now requires proto files to be properly formatted with clang-format. [[PR](https://github.com/prysmaticlabs/prysm/pull/14831)]. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14831)
+- Improved test coverage of beacon-chain/core/electra/churn.go. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14837)
+- Update electra spec test to beta1. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14841)
+- Move deposit request nil check to apply all. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14849)
+- Do not mark blocks as invalid on context deadlines during state transition. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14838)
+- Update electra core processing to not mark block bad if execution request error. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14826)
+- Dependency: Updated go-ethereum to v1.14.13. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14872)
+- improving readability on proposer settings loader. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14868)
+- Removes existing validator.processSlot span and adds validator.processSlot span to slotCtx. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14874)
+- DownloadFinalizedData has moved from the api/client package to beacon-chain/sync/checkpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14871)
+- Updated Blob-Batch-Limit to increase to 192 for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14883)
+- Updated Blob-Batch-Limit-Burst-Factor to increase to 3. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14883)
+- Changed the derived batch limit when serving blobs. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14883)
+- Updated go-libp2p-pubsub to v0.13.0. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14890)
+- Rename light client flag from `enable-lightclient` to `enable-light-client`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14887)
+- Update electra spec test to beta2. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14901)
+
+### Removed
+
+- Cleanup ProcessSlashings method to remove unnecessary argument. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14762)
+- Remove `/proto/eth/v2` directory. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14765)
+- Remove `/memsize/` pprof endpoint as it will no longer be supported in go 1.23. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14351)
+- Clean `TestCanUpgrade*` tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14791)
+- Remove `Copy()` from the `ReadOnlyBeaconBlock` interface. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14811)
+- Removed a tracing span on signature requests. These requests usually took less than 5 nanoseconds and are generally not worth tracing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14864)
+
+### Fixed
+
+- Added check to prevent nil pointer deference or out of bounds array access when validating the BLSToExecutionChange on an impossibly nil validator. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14705)
+- EIP-7691: Ensure new blobs subnets are subscribed on epoch in advance. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14759)
+- Fix kzg commitment inclusion proof depth minimal value. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14787)
+- Replace exampleIP to `96.7.129.13`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14795)
+- Fixed a p2p test to reliably return a static IP through DNS resolution. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14800)
+- `ToBlinded`: Use Fulu struct for Fulu (instead of Electra). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14797)
+- fix panic with type cast on pbgenericblock(). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14801)
+- Prysmctl generate genesis state: fix truncation of ExtraData to 32 bytes to satisfy SSZ marshaling. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14803)
+- added conditional evaluators to fix scenario e2e tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14798)
+- Use `SingleAttestation` for Fulu in p2p attestation map. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14809)
+- `UpgradeToFulu`: Respect the specification. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14821)
+- `nodeFilter`: Implement `filterPeerForBlobSubnet` to avoid error logs. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14822)
+- Fixed deposit packing for post-Electra: early return if EIP-6110 is applied. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14697)
+- Fix batch process new pending deposits by getting validators from state. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14827)
+- Fix handling unfound block at slot. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14852)
+- Fixed incorrect attester slashing length check. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14833)
+- Fix monitor service for Electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14853)
+- add more nil checks on ToConsensus functions for added safety. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14867)
+- Fix electra state to safe share references on pending fields when append. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14895)
+- Add missing config values from the spec. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14903)
+- We remove the unused `rebuildTrie` assignments for fields which do not use them. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14906)
+- fix block api endpoint to handle blocks with the same structure but on different forks (i.e. fulu and electra). [[PR]](https://github.com/prysmaticlabs/prysm/pull/14897)
+- We change how we track blob indexes during their reconstruction from the EL to prevent. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14909)
+- We now use the correct maximum value when serving blobs for electra blocks. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14910)
+
+### Security
+
+- go version upgrade to 1.22.10 for CVE CVE-2024-34156. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14729)
+- Update golang.org/x/crypto to v0.31.0 to address CVE-2024-45337. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14777)
+- Update golang.org/x/net to v0.33.0 to address CVE-2024-45338. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14780)
+
+## [v5.2.0](https://github.com/prysmaticlabs/prysm/compare/v5.1.2...v5.2.0)
+
+Updating to this release is highly recommended, especially for users running v5.1.1 or v5.1.2.
+This release is **mandatory** for all validator clients using mev-boost with a gas limit increase.
+Without upgrading to this release, validator clients will default to using local execution blocks
+when the gas limit starts to increase.
+
+This release has several fixes and new features. In this release, we have enabled QUIC protocol by
+default, which uses port 13000 for `--p2p-quic-port`. This may be a [breaking change](https://github.com/prysmaticlabs/prysm/pull/14688#issuecomment-2516713826)
+if you're using port 13000 already. This release has some improvements for raising the gas limit,
+but there are [known issues](https://hackmd.io/@ttsao/prysm-gas-limit) with the proposer settings
+file provided gas limit not being respected for mev-boost outsourced blocks. Signalling an increase
+for the gas limit works perfectly for local block production as of this release. See [pumpthegas.org](https://pumpthegas.org) for more info on raising the gas limit on L1.
+
+Notable features:
+- Prysm can reuse blobs from the EL via engine_getBlobsV1, [potentially saving bandwidth](https://hackmd.io/@ttsao/get-blobs-early-results).
+- QUIC is enabled by default. This is a UDP based networking protocol with default port 13000.
 
 ### Added
 
@@ -27,6 +311,14 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Added validator index label to `validator_statuses` metric.
 - Added Validator REST mode use of Attestation V2 endpoints and Electra attestations.
 - PeerDAS: Added proto for `DataColumnIdentifier`, `DataColumnSidecar`, `DataColumnSidecarsByRangeRequest` and `MetadataV2`.
+- Better attestation packing for Electra. [PR](https://github.com/prysmaticlabs/prysm/pull/14534)
+- P2P: Add logs when a peer is (dis)connected. Add the reason of the disconnection when we initiate it.
+- Added a Prometheus error counter metric for HTTP requests to track beacon node requests.
+- Added a Prometheus error counter metric for SSE requests.
+- Save light client updates and bootstraps in DB.
+- Added more comprehensive tests for `BlockToLightClientHeader`. [PR](https://github.com/prysmaticlabs/prysm/pull/14699)
+- Added light client feature flag check to RPC handlers. [PR](https://github.com/prysmaticlabs/prysm/pull/14736)
+- Light client: Add better error handling. [PR](https://github.com/prysmaticlabs/prysm/pull/14749)
 
 ### Changed
 
@@ -36,7 +328,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Updated the default `scrape-interval` in `Client-stats` to 2 minutes to accommodate Beaconcha.in API rate limits.
 - Switch to compounding when consolidating with source==target.
 - Revert block db save when saving state fails.
-- Return false from HasBlock if the block is being synced. 
+- Return false from HasBlock if the block is being synced.
 - Cleanup forkchoice on failed insertions.
 - Use read only validator for core processing to avoid unnecessary copying.
 - Use ROBlock across block processing pipeline.
@@ -49,7 +341,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Simplified `EjectedValidatorIndices`.
 - `engine_newPayloadV4`,`engine_getPayloadV4` are changes due to new execution request serialization decisions, [PR](https://github.com/prysmaticlabs/prysm/pull/14580)
 - Fixed various small things in state-native code.
-- Use ROBlock earlier in block syncing pipeline. 
+- Use ROBlock earlier in block syncing pipeline.
 - Changed the signature of `ProcessPayload`.
 - Only Build the Protobuf state once during serialization.
 - Capella blocks are execution.
@@ -61,16 +353,29 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Updated light client protobufs. [PR](https://github.com/prysmaticlabs/prysm/pull/14650)
 - Added `Eth-Consensus-Version` header to `ListAttestationsV2` and `GetAggregateAttestationV2` endpoints.
 - Updated light client consensus types. [PR](https://github.com/prysmaticlabs/prysm/pull/14652)
+- Update earliest exit epoch for upgrade to electra
+- Add missed exit checks to consolidation processing
+- Fixed pending deposits processing on Electra.
+- Modified `ListAttestationsV2`, `GetAttesterSlashingsV2` and `GetAggregateAttestationV2` endpoints to use slot to determine fork version.
+- Improvements to HTTP response handling. [pr](https://github.com/prysmaticlabs/prysm/pull/14673)
+- Updated `Blobs` endpoint to return additional metadata fields.
+- Made QUIC the default method to connect with peers.
+- Check kzg commitments align with blobs and proofs for beacon api end point.
+- Revert "Proposer checks gas limit before accepting builder's bid".
+- Updated quic-go to v0.48.2 .
 
 ### Deprecated
 
 - `/eth/v1alpha1/validator/activation/stream` grpc wait for activation stream is deprecated. [pr](https://github.com/prysmaticlabs/prysm/pull/14514)
+- `--interop-genesis-time` and `--interop-num-validators` have been deprecated in the beacon node as the functionality has been removed. These flags have no effect.
 
 ### Removed
 
 - Removed finalized validator index cache, no longer needed.
 - Removed validator queue position log on key reload and wait for activation.
 - Removed outdated spectest exclusions for EIP-6110.
+- Removed support for starting a beacon node with a deterministic interop genesis state via interop flags. Alternatively, create a genesis state with prysmctl and use `--genesis-state`. This removes about 9Mb (~11%) of unnecessary code and dependencies from the final production binary.
+- Removed kzg proof check from blob reconstructor.
 
 ### Fixed
 
@@ -83,7 +388,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Fix `--backfill-oldest-slot` handling - this flag was totally broken, the code would always backfill to the default slot [pr](https://github.com/prysmaticlabs/prysm/pull/14584)
 - Fix keymanager API should return corrected error format for malformed tokens
 - Fix keymanager API so that get keys returns an empty response instead of a 500 error when using an unsupported keystore.
-- Small log imporvement, removing some redundant or duplicate logs
+- Small log improvement, removing some redundant or duplicate logs
 - EIP7521 - Fixes withdrawal bug by accounting for pending partial withdrawals and deducting already withdrawn amounts from the sweep balance. [PR](https://github.com/prysmaticlabs/prysm/pull/14578)
 - unskip electra merkle spec test
 - Fix panic in validator REST mode when checking status after removing all keys
@@ -91,13 +396,20 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - corrects nil check on some interface attestation types
 - temporary solution to handling electra attesation and attester_slashing events. [pr](14655)
 - Diverse log improvements and comment additions.
-
+- Validate that each committee bitfield in an aggregate contains at least one non-zero bit
+- P2P: Avoid infinite loop when looking for peers in small networks.
+- Fixed another rollback bug due to a context deadline.
+- Fix checkpoint sync bug on holesky. [pr](https://github.com/prysmaticlabs/prysm/pull/14689)
+- Fix proposer boost spec tests being flakey by adjusting start time from 3 to 2s into slot.
+- Fix segmentation fault in E2E when light-client feature flag is enabled. [PR](https://github.com/prysmaticlabs/prysm/pull/14699)
+- Fix `searchForPeers` infinite loop in small networks.
+- Fix slashing pool behavior to enforce MaxAttesterSlashings limit in Electra version.
 
 ### Security
 
-## [v5.1.2](https://github.com/prysmaticlabs/prysm/compare/v5.1.1...v5.1.2) - 2024-10-16 
+## [v5.1.2](https://github.com/prysmaticlabs/prysm/compare/v5.1.1...v5.1.2) - 2024-10-16
 
-This is a hotfix release with one change. 
+This is a hotfix release with one change.
 
 Prysm v5.1.1 contains an updated implementation of the beacon api streaming events endpoint. This
 new implementation contains a bug that can cause a panic in certain conditions. The issue is
@@ -106,23 +418,23 @@ meantime we are issuing a patch that recovers from the panic to prevent the node
 
 This only impacts the v5.1.1 release beacon api event stream endpoints. This endpoint is used by the
 prysm REST mode validator (a feature which requires the validator to be configured to use the beacon
-api intead of prysm's stock grpc endpoints) or accessory software that connects to the events api,
+api instead of prysm's stock grpc endpoints) or accessory software that connects to the events api,
 like https://github.com/ethpandaops/ethereum-metrics-exporter
 
-### Fixed 
+### Fixed
 
 - Recover from panics when writing the event stream [#14545](https://github.com/prysmaticlabs/prysm/pull/14545)
 
 ## [v5.1.1](https://github.com/prysmaticlabs/prysm/compare/v5.1.0...v5.1.1) - 2024-10-15
 
-This release has a number of features and improvements. Most notably, the feature flag 
-`--enable-experimental-state` has been flipped to "opt out" via `--disable-experimental-state`. 
+This release has a number of features and improvements. Most notably, the feature flag
+`--enable-experimental-state` has been flipped to "opt out" via `--disable-experimental-state`.
 The experimental state management design has shown significant improvements in memory usage at
 runtime. Updates to libp2p's gossipsub have some bandwidith stability improvements with support for
-IDONTWANT control messages. 
+IDONTWANT control messages.
 
 The gRPC gateway has been deprecated from Prysm in this release. If you need JSON data, consider the
-standardized beacon-APIs. 
+standardized beacon-APIs.
 
 Updating to this release is recommended at your convenience.
 
@@ -164,7 +476,7 @@ Updating to this release is recommended at your convenience.
 - `grpc-gateway-corsdomain` is renamed to http-cors-domain. The old name can still be used as an alias.
 - `api-timeout` is changed from int flag to duration flag, default value updated.
 - Light client support: abstracted out the light client headers with different versions.
-- `ApplyToEveryValidator` has been changed to prevent misuse bugs, it takes a closure that takes a `ReadOnlyValidator` and returns a raw pointer to a `Validator`. 
+- `ApplyToEveryValidator` has been changed to prevent misuse bugs, it takes a closure that takes a `ReadOnlyValidator` and returns a raw pointer to a `Validator`.
 - Removed gorilla mux library and replaced it with net/http updates in go 1.22.
 - Clean up `ProposeBlock` for validator client to reduce cognitive scoring and enable further changes.
 - Updated k8s-io/client-go to v0.30.4 and k8s-io/apimachinery to v0.30.4
@@ -175,7 +487,7 @@ Updating to this release is recommended at your convenience.
 - Updated Sepolia bootnodes.
 - Make committee aware packing the default by deprecating `--enable-committee-aware-packing`.
 - Moved `ConvertKzgCommitmentToVersionedHash` to the `primitives` package.
-- Updated correlation penalty for EIP-7251. 
+- Updated correlation penalty for EIP-7251.
 
 ### Deprecated
 - `--disable-grpc-gateway` flag is deprecated due to grpc gateway removal.
@@ -349,7 +661,7 @@ Updating to this release is recommended at your earliest convenience, especially
 - use time.NewTimer() to avoid possible memory leaks
 - paranoid underflow protection without error handling
 - Fix CommitteeAssignments to not return every validator
-- Fix dependent root retrival genesis case
+- Fix dependent root retrieval genesis case
 - Restrict Dials From Discovery
 - Always close cache warm chan to prevent blocking
 - Keep only the latest value in the health channel
@@ -416,6 +728,7 @@ block profit. If you want to preserve the existing behavior, set --local-block-v
 - Set default LocalBlockValueBoost to 10
 - Add bid value metrics
 - REST VC metrics
+- `startDB`: Add log when checkpoint sync.
 
 ### Changed
 
@@ -500,7 +813,7 @@ block profit. If you want to preserve the existing behavior, set --local-block-v
 - handle special case of batch size=1
 - Always Set Inprogress Boolean In Cache
 - Builder APIs: adding headers to post endpoint
-- Rename mispelled variable
+- Rename misspelled variable
 - allow blob by root within da period
 - Rewrite Pruning Implementation To Handle EIP 7045
 - Set default fee recipient if tracked val fails
@@ -570,7 +883,7 @@ Known Issues
 - Support beacon_committee_selections
 - /eth/v1/beacon/deposit_snapshot
 - Docker images now have coreutils pre-installed
-- da_waited_time_milliseconds tracks total time waiting for data availablity check in ReceiveBlock
+- da_waited_time_milliseconds tracks total time waiting for data availability check in ReceiveBlock
 - blob_written, blob_disk_count, blob_disk_bytes new metrics for tracking blobs on disk
 - Backfill supports blob backfilling
 - Add mainnet deneb fork epoch config
@@ -648,34 +961,34 @@ AVX support (eg Celeron) after the Deneb fork. This is not an issue for mainnet.
 
 - Linter: Wastedassign linter enabled to improve code quality.
 - API Enhancements:
-    - Added payload return in Wei for /eth/v3/validator/blocks.
-    - Added Holesky Deneb Epoch for better epoch management.
+  - Added payload return in Wei for /eth/v3/validator/blocks.
+  - Added Holesky Deneb Epoch for better epoch management.
 - Testing Enhancements:
-    - Clear cache in tests of core helpers to ensure test reliability.
-    - Added Debug State Transition Method for improved debugging.
-    - Backfilling test: Enabled backfill in E2E tests for more comprehensive coverage.
+  - Clear cache in tests of core helpers to ensure test reliability.
+  - Added Debug State Transition Method for improved debugging.
+  - Backfilling test: Enabled backfill in E2E tests for more comprehensive coverage.
 - API Updates: Re-enabled jwt on keymanager API for enhanced security.
 - Logging Improvements: Enhanced block by root log for better traceability.
 - Validator Client Improvements:
-    - Added Spans to Core Validator Methods for enhanced monitoring.
-    - Improved readability in validator client code for better maintenance (various commits).
+  - Added Spans to Core Validator Methods for enhanced monitoring.
+  - Improved readability in validator client code for better maintenance (various commits).
 
 ### Changed
 
 - Optimizations and Refinements:
-    - Lowered resource usage in certain processes for efficiency.
-    - Moved blob rpc validation closer to peer read for optimized processing.
-    - Cleaned up validate beacon block code for clarity and efficiency.
-    - Updated Sepolia Deneb fork epoch for alignment with network changes.
-    - Changed blob latency metrics to milliseconds for more precise measurement.
-    - Altered getLegacyDatabaseLocation message for better clarity.
-    - Improved wait for activation method for enhanced performance.
-    - Capitalized Aggregated Unaggregated Attestations Log for consistency.
-    - Modified HistoricalRoots usage for accuracy.
-    - Adjusted checking of attribute emptiness for efficiency.
+  - Lowered resource usage in certain processes for efficiency.
+  - Moved blob rpc validation closer to peer read for optimized processing.
+  - Cleaned up validate beacon block code for clarity and efficiency.
+  - Updated Sepolia Deneb fork epoch for alignment with network changes.
+  - Changed blob latency metrics to milliseconds for more precise measurement.
+  - Altered getLegacyDatabaseLocation message for better clarity.
+  - Improved wait for activation method for enhanced performance.
+  - Capitalized Aggregated Unaggregated Attestations Log for consistency.
+  - Modified HistoricalRoots usage for accuracy.
+  - Adjusted checking of attribute emptiness for efficiency.
 - Database Management:
-    - Moved --db-backup-output-dir as a deprecated flag for database management simplification.
-    - Added the Ability to Defragment the Beacon State for improved database performance.
+  - Moved --db-backup-output-dir as a deprecated flag for database management simplification.
+  - Added the Ability to Defragment the Beacon State for improved database performance.
 - Dependency Update: Bumped quic-go version from 0.39.3 to 0.39.4 for up-to-date dependencies.
 
 ### Removed
@@ -686,12 +999,12 @@ AVX support (eg Celeron) after the Deneb fork. This is not an issue for mainnet.
 ### Fixed
 
 - Bug Fixes:
-    - Fixed off by one error for improved accuracy.
-    - Resolved small typo in error messages for clarity.
-    - Addressed minor issue in blsToExecChange validator for better validation.
-    - Corrected blobsidecar json tag for commitment inclusion proof.
-    - Fixed ssz post-requests content type check.
-    - Resolved issue with port logging in bootnode.
+  - Fixed off by one error for improved accuracy.
+  - Resolved small typo in error messages for clarity.
+  - Addressed minor issue in blsToExecChange validator for better validation.
+  - Corrected blobsidecar json tag for commitment inclusion proof.
+  - Fixed ssz post-requests content type check.
+  - Resolved issue with port logging in bootnode.
 - Test Fixes: Re-enabled Slasher E2E Test for more comprehensive testing.
 
 ### Security
@@ -745,7 +1058,7 @@ and Raspberry Pi users.
 - Add Goerli Deneb Fork Epoch
 - Use deneb key for deneb state in saveStatesEfficientInternal
 - Initialize Inactivity Scores Correctly
-- Excluse DA wait time for chain processing time
+- Excludes DA wait time for chain processing time
 - Initialize sig cache for verification.Initializer
 - Verify roblobs
 - KZG Commitment inclusion proof verifier
@@ -778,7 +1091,7 @@ and Raspberry Pi users.
 - Exit early if blob by root request is empty
 - Request missing blobs while processing pending queue
 - Check blob exists before requesting from peer
-- Passing block as arugment for sidecar validation
+- Passing block as argument for sidecar validation
 
 #### Blob Management
 
@@ -1075,13 +1388,13 @@ _Most of the PRs here involve shifting our http endpoints to using vanilla http
 - Remove no-op cancel func
 - Update Terms of Service
 - fix head slot in log
-- DEPRECTATION: Remove exchange transition configuration call
+- DEPRECATION: Remove exchange transition configuration call
 - fix segmentation fork when Capella for epoch is MaxUint64
 - Return Error Gracefully When Removing 4881 Flag
 - Add zero length check on indices during NextSyncCommitteeIndices
 - Replace Empty Slice Literals with Nil Slices
 - Refactor Error String Formatting According to Go Best Practices
-- Fix redundant type converstion
+- Fix redundant type conversion
 - docs: fix typo
 - Add Clarification To Sync Committee Cache
 - Fix typos
@@ -1103,7 +1416,7 @@ small set of users.
 
 ### Security
 
-No security issues in thsi release.
+No security issues in this release.
 
 ## [v4.1.0](https://github.com/prysmaticlabs/prysm/compare/v4.0.8...v4.1.0) - 2023-08-22
 
@@ -1118,9 +1431,9 @@ No security issues in thsi release.
   now features runtime detection, automatically enabling optimized code paths if your CPU supports it.
 - **Multiarch Containers Preview Available**: multiarch (:wave: arm64 support :wave:) containers will be offered for
   preview at the following locations:
-    - Beacon Chain: [gcr.io/prylabs-dev/prysm/beacon-chain:v4.1.0](gcr.io/prylabs-dev/prysm/beacon-chain:v4.1.0)
-    - Validator: [gcr.io/prylabs-dev/prysm/validator:v4.1.0](gcr.io/prylabs-dev/prysm/validator:v4.1.0)
-    - Please note that in the next cycle, we will exclusively use these containers at the canonical URLs.
+  - Beacon Chain: [gcr.io/prylabs-dev/prysm/beacon-chain:v4.1.0](gcr.io/prylabs-dev/prysm/beacon-chain:v4.1.0)
+  - Validator: [gcr.io/prylabs-dev/prysm/validator:v4.1.0](gcr.io/prylabs-dev/prysm/validator:v4.1.0)
+  - Please note that in the next cycle, we will exclusively use these containers at the canonical URLs.
 
 ### Added
 
@@ -1619,7 +1932,7 @@ notes [here](https://hackmd.io/TtyFurRJRKuklG3n8lMO9Q). This release is **strong
 Note: The released docker images are using the portable version of the blst cryptography library. The Prysm team will
 release docker images with the non-portable blst library as the default image. In the meantime, you can compile docker
 images with blst non-portable locally with the `--define=blst_modern=true` bazel flag, use the "-modern-" assets
-attached to releases, or set environment varaible USE_PRYSM_MODERN=true when using prysm.sh.
+attached to releases, or set environment variable USE_PRYSM_MODERN=true when using prysm.sh.
 
 ### Added
 
@@ -1968,7 +2281,7 @@ There are some known issues with this release.
 - Beacon node can bootstrap from non-genesis state (i.e bellatrix state)
 - Refactor bytesutil, add support for go1.20 slice to array conversions
 - Add Span information for attestation record save request
-- Matric addition
+- Metric addition
 - Identify invalid signature within batch verification
 - Support for getting consensus values from beacon config
 - EIP-4881: Spec implementation
@@ -2034,7 +2347,7 @@ See [flashbots/mev-boost#404](https://github.com/flashbots/mev-boost/issues/404)
 - Added more histogram metrics for block arrival latency times block_arrival_latency_milliseconds
 - Priority queue RetrieveByKey now uses read lock instead of write lock
 - Use custom types for certain ethclient requests. Fixes an issue when using prysm on gnosis chain.
-- Updted forkchoice endpoint /eth/v1/debug/forkchoice (was /eth/v1/debug/beacon/forkchoice)
+- Updated forkchoice endpoint /eth/v1/debug/forkchoice (was /eth/v1/debug/beacon/forkchoice)
 - Include empty fields in builder json client.
 - Computing committee assignments for slots older than the oldest historical root in the beacon state is now forbidden
 
@@ -2266,7 +2579,7 @@ There are no security updates in this release.
   removed: `GetBeaconState`, `ProduceBlock`, `ListForkChoiceHeads`, `ListBlocks`, `SubmitValidatorRegistration`, `GetBlock`, `ProposeBlock`
 - API: Forkchoice method `GetForkChoice` has been removed.
 - All previously deprecated feature flags have been
-  removed. `--enable-active-balance-cache`, `--correctly-prune-canonical-atts`, `--correctly-insert-orphaned-atts`, `--enable-next-slot-state-cache`, `--enable-batch-gossip-verification`, `--enable-get-block-optimizations`, `--enable-balance-trie-computation`, `--disable-next-slot-state-cache`, `--attestation-aggregation-strategy`, `--attestation-aggregation-force-opt-maxcover`, `--pyrmont`, `--disable-get-block-optimizations`, `--disable-proposer-atts-selection-using-max-cover`, `--disable-optimized-balance-update`, `--disable-active-balance-cache`, `--disable-balance-trie-computation`, `--disable-batch-gossip-verification`, `--disable-correctly-prune-canonical-atts`, `--disable-correctly-insert-orphaned-atts`, `--enable-native-state`, `--enable-peer-scorer`, `--enable-gossip-batch-aggregation`, `--experimental-disable-boundry-checks`
+  removed. `--enable-active-balance-cache`, `--correctly-prune-canonical-atts`, `--correctly-insert-orphaned-atts`, `--enable-next-slot-state-cache`, `--enable-batch-gossip-verification`, `--enable-get-block-optimizations`, `--enable-balance-trie-computation`, `--disable-next-slot-state-cache`, `--attestation-aggregation-strategy`, `--attestation-aggregation-force-opt-maxcover`, `--pyrmont`, `--disable-get-block-optimizations`, `--disable-proposer-atts-selection-using-max-cover`, `--disable-optimized-balance-update`, `--disable-active-balance-cache`, `--disable-balance-trie-computation`, `--disable-batch-gossip-verification`, `--disable-correctly-prune-canonical-atts`, `--disable-correctly-insert-orphaned-atts`, `--enable-native-state`, `--enable-peer-scorer`, `--enable-gossip-batch-aggregation`, `--experimental-disable-boundary-checks`
 - Validator Web API: Removed unused ImportAccounts and DeleteAccounts rpc options
 
 ### Fixed
@@ -2482,7 +2795,7 @@ There are two known issues with this release:
 - Bellatrix support. See [kiln testnet instructions](https://hackmd.io/OqIoTiQvS9KOIataIFksBQ?view)
 - Weak subjectivity sync / checkpoint sync. This is an experimental feature and may have unintended side effects for
   certain operators serving historical data. See
-  the [documentation](https://docs.prylabs.network/docs/next/prysm-usage/checkpoint-sync) for more details.
+  the [documentation](https://docs.prylabs.network/docs/prysm-usage/checkpoint-sync) for more details.
 - A faster build of blst for beacon chain on linux amd64. Use the environment variable `USE_PRYSM_MODERN=true` with
   prysm.sh, use the "modern" binary, or bazel build with `--define=blst_modern=true`.
 - Vectorized sha256. This may have performance improvements with use of the new flag `--enable-vectorized-htr`.
@@ -2663,7 +2976,7 @@ notes [here](https://github.com/prysmaticlabs/prysm-web-ui/releases/tag/v1.0.0)
 - Added uint64 overflow protection
 - Sync committee pool returns empty slice instead of nil on cache miss
 - Improved description of datadir flag
-- Simplied web password requirements
+- Simplified web password requirements
 - Web JWT tokens no longer expire.
 - Updated keymanager protos
 - Watch and update jwt secret when auth token file updated on disk.
@@ -2674,7 +2987,7 @@ notes [here](https://github.com/prysmaticlabs/prysm-web-ui/releases/tag/v1.0.0)
 - Refactor for weak subjectivity sync implementation
 - Update naming for Atlair previous epoch attester
 - Remove duplicate MerkleizeTrieLeaves method.
-- Add explict error for validator flag checks on out of bound positions
+- Add explicit error for validator flag checks on out of bound positions
 - Simplify method to check if the beacon chain client should update the justified epoch value.
 - Rename web UI performance endpoint to "summary"
 - Refactor powchain service to be more functional
@@ -2700,7 +3013,7 @@ notes [here](https://github.com/prysmaticlabs/prysm-web-ui/releases/tag/v1.0.0)
   Upstream go-ethereum is now used with familiar go.mod tooling.
 - Removed duplicate aggergation validation p2p pipelines.
 - Metrics calculation removed extra condition
-- Removed superflous errors from peer scoring parameters registration
+- Removed superfluous errors from peer scoring parameters registration
 
 ### Fixed
 
@@ -2942,4 +3255,4 @@ There are no security updates in this release.
 
 # Older than v2.0.0
 
-For changelog history for releases older than v2.0.0, please refer to https://github.com/prysmaticlabs/prysm/releases
+For changelog history for releases older than v2.0.0, please refer to https://github.com/prysmaticlabs/prysm/releases

CONTRIBUTING.md

@@ -125,11 +125,11 @@ Navigate to your fork of the repo on GitHub. On the upper left where the current
 
 **16. Add an entry to CHANGELOG.md.**
 
-If your change is user facing, you must include a CHANGELOG.md entry. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
+All PRs must must include a changelog fragment file in the `changelog` directory. If your change is not user-facing or should not be mentioned in the changelog for some other reason, you may use the `Ignored` changelog section in your fragment's header to satisfy this requirement without altering the final release changelog. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
 
 **17. Create a pull request.**
 
-Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base master”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
+Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base develop”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
 
 **18. Respond to comments by Core Contributors.**
 
@@ -177,16 +177,10 @@ $ git push myrepo feature-in-progress-branch -f
 
 ## Maintaining CHANGELOG.md
 
-This project follows the changelog guidelines from [keepachangelog.com](https://keepachangelog.com/en/1.1.0/).
-
-All PRs with user facing changes should have an entry in the CHANGELOG.md file and the change should be categorized in the appropriate category within the "Unreleased" section. The categories are:
-
--  `Added` for new features.
--  `Changed` for changes in existing functionality.
--  `Deprecated` for soon-to-be removed features.
--  `Removed` for now removed features.
--  `Fixed` for any bug fixes.
--  `Security` in case of vulnerabilities. Please see the [Security Policy](SECURITY.md) for responsible disclosure before adding a change with this category.
+This project follows the changelog guidelines from [keepachangelog.com](https://keepachangelog.com/en/1.1.0/). In order to minimize conflicts and workflow headaches, we chose to implement a changelog management
+strategy that uses changelog "fragment" files, managed by our changelog management tool called `unclog`. Each PR must include a new changelog fragment file in the `changelog` directory, as specified by unclog's
+[README.md](https://github.com/OffchainLabs/unclog?tab=readme-ov-file#what-is-a-changelog-fragment). As the `unclog` README suggests in the [Best Practices](https://github.com/OffchainLabs/unclog?tab=readme-ov-file#best-practices) section, 
+the standard naming convention for your PR's fragment file, to avoid conflicting with another fragment file, is `changelog/<github user name>_<PR branch name>.md`.
 
 ### Releasing
 

DEPENDENCIES.md

@@ -55,7 +55,7 @@ bazel build //beacon-chain --config=release
 ## Adding / updating dependencies
 
 1. Add your dependency as you would with go modules. I.e. `go get ...`
-1. Run `bazel run //:gazelle -- update-repos -from_file=go.mod` to update the bazel managed dependencies.
+1. Run `bazel run //:gazelle -- update-repos -from_file=go.mod -to_macro=deps.bzl%prysm_deps -prune=true` to update the bazel managed dependencies.
 
 Example:
 

INTEROP.md

@@ -2,18 +2,21 @@
 
 This README details how to setup Prysm for interop testing for usage with other Ethereum consensus clients.
 
+> [!IMPORTANT]  
+> This guide is likely to be outdated. The Prysm team does not have capacity to troubleshoot
+> outdated interop guides or instructions. If you experience issues with this guide, please file an
+> issue for visibility and propose fixes, if possible.
+
 ## Installation & Setup
 
 1. Install [Bazel](https://docs.bazel.build/versions/master/install.html) **(Recommended)**
 2. `git clone https://github.com/prysmaticlabs/prysm && cd prysm`
-3. `bazel build //...`
+3. `bazel build //cmd/...`
 
 ## Starting from Genesis
 
-Prysm supports a few ways to quickly launch a beacon node from basic configurations:
-
-- `NumValidators + GenesisTime`: Launches a beacon node by deterministically generating a state from a num-validators flag along with a genesis time **(Recommended)**
-- `SSZ Genesis`: Launches a beacon node  from a .ssz file containing a SSZ-encoded, genesis beacon state
+Prysm can be started from a built-in mainnet genesis state, or started with a provided genesis state by
+using the `--genesis-state` flag and providing a path to the genesis.ssz file.
 
 ## Generating a Genesis State
 
@@ -21,21 +24,34 @@ To setup the necessary files for these quick starts, Prysm provides a tool to ge
 a deterministically generated set of validator private keys following the official interop YAML format 
 [here](https://github.com/ethereum/eth2.0-pm/blob/master/interop/mocked_start).
 
-You can use `bazel run //tools/genesis-state-gen` to create a deterministic genesis state for interop.
+You can use `prysmctl` to create a deterministic genesis state for interop.
 
-### Usage
-
-- **--genesis-time** uint: Unix timestamp used as the genesis time in the generated genesis state (defaults to now)
-- **--num-validators** int: Number of validators to deterministically include in the generated genesis state
-- **--output-ssz** string: Output filename of the SSZ marshaling of the generated genesis state
-- **--config-name=interop** string: name of the beacon chain config to use when generating the state. ex mainnet|minimal|interop
-
-The example below creates 64 validator keys, instantiates a genesis state with those 64 validators and with genesis unix timestamp 1567542540,
-and finally writes a ssz encoded output to ~/Desktop/genesis.ssz. This file can be used to kickstart the beacon chain in the next section. When using the `--interop-*` flags, the beacon node will assume the `interop` config should be used, unless a different config is specified on the command line.
+```sh
+# Download (or create) a chain config file.
+curl https://raw.githubusercontent.com/ethereum/consensus-specs/refs/heads/dev/configs/minimal.yaml -o /tmp/minimal.yaml
 
+# Run prysmctl to generate genesis with a 2 minute genesis delay and 256 validators. 
+bazel run //cmd/prysmctl --config=minimal -- \
+  testnet generate-genesis \
+  --genesis-time-delay=120 \
+  --num-validators=256 \
+  --output-ssz=/tmp/genesis.ssz \
+  --chain-config-file=/tmp/minimal.yaml
 ```
-bazel run //tools/genesis-state-gen -- --config-name interop --output-ssz ~/Desktop/genesis.ssz --num-validators 64 --genesis-time 1567542540
-```
+
+The flags are explained below:
+- `bazel run //cmd/prysmctl` is the bazel command to compile and run prysmctl.
+- `--config=minimal` is a bazel build time configuration flag to compile Prysm with minimal state constants.
+- `--` is an argument divider to tell bazel that everything after this divider should be passed as arguments to prysmctl. Without this divider, it isn't clear to bazel if the arguments are meant to be build time arguments or runtime arguments so the operation complains and fails to build without this divider.
+- `testnet` is the primary command argument for prysmctl.
+- `generate-genesis` is the subcommand to `testnet` in prysmctl.
+- `--genesis-time-delay` uint: The number of seconds in the future to define genesis. Example: a value of 60 will set the genesis time to 1 minute in the future. This should be sufficiently large enough to allow for you to start the beacon node before the genesis time. 
+- `--num-validators` int: Number of validators to deterministically include in the generated genesis state
+- `--output-ssz` string: Output filename of the SSZ marshaling of the generated genesis state
+- `--chain-config-file` string: Filepath to a chain config yaml file.
+
+Note: This guide saves items to the `/tmp/` directory which will not persist if your machine is
+restarted. Consider tweaking the arguments if persistence is needed.
 
 ## Launching a Beacon Node + Validator Client
 
@@ -44,45 +60,33 @@ bazel run //tools/genesis-state-gen -- --config-name interop --output-ssz ~/Desk
 Open up two terminal windows, run:
 
 ```
-bazel run //beacon-chain -- \
---bootstrap-node= \
---deposit-contract 0x8A04d14125D0FDCDc742F4A05C051De07232EDa4 \
---datadir=/tmp/beacon-chain-interop \
---force-clear-db \
---min-sync-peers=0 \
---interop-num-validators 64 \
---interop-eth1data-votes
+bazel run //cmd/beacon-chain --config=minimal -- \
+  --minimal-config \
+  --bootstrap-node= \
+  --deposit-contract 0x8A04d14125D0FDCDc742F4A05C051De07232EDa4 \
+  --datadir=/tmp/beacon-chain-minimal-devnet \
+  --force-clear-db \
+  --min-sync-peers=0 \
+  --genesis-state=/tmp/genesis.ssz \
+  --chain-config-file=/tmp/minimal.yaml
 ```
 
-This will deterministically generate a beacon genesis state and start
-the system with 64 validators and the genesis time set to the current unix timestamp.
-Wait a bit until your beacon chain starts, and in the other window:
+This will start the system with 256 validators. The flags used can be explained as such:
+
+- `bazel run //cmd/beacon-chain --config=minimal` builds and runs the beacon node in minimal build configuration.
+- `--` is a flag divider to distinguish between bazel flags and flags that should be passed to the application. All flags and arguments after this divider are passed to the beacon chain.
+- `--minimal-config` tells the beacon node to use minimal network configuration. This is different from the compile time state configuration flag `--config=minimal` and both are required.
+- `--bootstrap-node=` disables the default bootstrap nodes. This prevents the client from attempting to peer with mainnet nodes.
+- `--datadir=/tmp/beacon-chain-minimal-devnet` sets the data directory in a temporary location. Change this to your preferred destination.
+- `--force-clear-db` will delete the beaconchain.db file without confirming with the user. This is helpful for iteratively running local devnets without changing the datadir, but less helpful for one off runs where there was no database in the data directory.
+- `--min-sync-peers=0` allows the beacon node to skip initial sync without peers. This is essential because Prysm expects at least a few peers to start the blockchain.
+- `--genesis-state=/tmp/genesis.ssz` defines the path to the generated genesis ssz file. The beacon node will use this as the initial genesis state.
+- `--chain-config-file=/tmp/minimal.yaml` defines the path to the yaml file with the chain configuration.
+
+As soon as the beacon node has started, start the validator in the other terminal window. 
 
 ```
-bazel run //validator -- --keymanager=interop --keymanageropts='{"keys":64}'
+bazel run //cmd/validator --config=minimal -- --datadir=/tmp/validator --interop-num-validators=256 --minimal-config --suggested-fee-recipient=0x8A04d14125D0FDCDc742F4A05C051De07232EDa4
 ```
 
-This will launch and kickstart the system with your 64 validators performing their duties accordingly.
-
-### Launching from `genesis.ssz`
-
-Assuming you generated a `genesis.ssz` file with 64 validators, open up two terminal windows, run:
-
-```
- bazel run //beacon-chain -- \
---bootstrap-node= \
---deposit-contract 0x8A04d14125D0FDCDc742F4A05C051De07232EDa4 \
---datadir=/tmp/beacon-chain-interop \
---force-clear-db \
---min-sync-peers=0 \
---interop-genesis-state /path/to/genesis.ssz \
---interop-eth1data-votes
-```
-
-Wait a bit until your beacon chain starts, and in the other window:
-
-```
-bazel run //validator -- --keymanager=interop --keymanageropts='{"keys":64}'
-```
-
-This will launch and kickstart the system with your 64 validators performing their duties accordingly.
+This will launch and kickstart the system with your 256 validators performing their duties accordingly.

README.md

@@ -1,5 +1,7 @@
-# Prysm: An Ethereum Consensus Implementation Written in Go
+<h1 align="left">Prysm: An Ethereum Consensus Implementation Written in Go</h1>
 
+<div align="left">
+  
 [![Build status](https://badge.buildkite.com/b555891daf3614bae4284dcf365b2340cefc0089839526f096.svg?branch=master)](https://buildkite.com/prysmatic-labs/prysm)
 [![Go Report Card](https://goreportcard.com/badge/github.com/prysmaticlabs/prysm)](https://goreportcard.com/report/github.com/prysmaticlabs/prysm)
 [![Consensus_Spec_Version 1.4.0](https://img.shields.io/badge/Consensus%20Spec%20Version-v1.4.0-blue.svg)](https://github.com/ethereum/consensus-specs/tree/v1.4.0)
@@ -7,31 +9,60 @@
 [![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysmaticlabs)
 [![GitPOAP Badge](https://public-api.gitpoap.io/v1/repo/prysmaticlabs/prysm/badge)](https://www.gitpoap.io/gh/prysmaticlabs/prysm)
 
-This is the core repository for Prysm, a [Golang](https://golang.org/) implementation of the [Ethereum Consensus](https://ethereum.org/en/developers/docs/consensus-mechanisms/#proof-of-stake) [specification](https://github.com/ethereum/consensus-specs), developed by [Offchain Labs](https://www.offchainlabs.com). See the [Changelog](https://github.com/prysmaticlabs/prysm/releases) for details of the latest releases and upcoming breaking changes.
+</div>
 
-### Getting Started
+---
 
-A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the [official documentation portal](https://docs.prylabs.network). If you still have questions, feel free to stop by our [Discord](https://discord.gg/prysmaticlabs).
+## 📖 Overview
 
-### Staking on Mainnet
+This is the core repository for Prysm, a [Golang](https://golang.org/) implementation of the [Ethereum Consensus](https://ethereum.org/en/developers/docs/consensus-mechanisms/#proof-of-stake) [specification](https://github.com/ethereum/consensus-specs), developed by [Offchain Labs](https://www.offchainlabs.com).
 
-To participate in staking, you can join the [official eth2 launchpad](https://launchpad.ethereum.org). The launchpad is the only recommended way to become a validator on mainnet. You can explore validator rewards/penalties via Bitfly's block explorer: [beaconcha.in](https://beaconcha.in), and follow the latest blocks added to the chain on [beaconscan](https://beaconscan.com).
+See the [Changelog](https://github.com/prysmaticlabs/prysm/releases) for details of the latest releases and upcoming breaking changes.
 
+---
+
+## 🚀 Getting Started
+
+A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the **[official documentation portal](https://docs.prylabs.network)**.
+
+💬 **Need help?** Join our **[Discord Community](https://discord.gg/prysmaticlabs)** for support.
+
+---
+
+## 🏆 Staking on Mainnet
+
+To participate in staking, you can join the **[official Ethereum launchpad](https://launchpad.ethereum.org)**. The launchpad is the **only recommended** way to become a validator on mainnet.
+
+🔍 Explore validator rewards/penalties:
+
+- **[beaconcha.in](https://beaconcha.in)**
+- **[beaconscan](https://beaconscan.com)**
+
+---
+
+## 🤝 Contributing
+
+### 🔥 Branches
 
-## Contributing
-### Branches
 Prysm maintains two permanent branches:
 
-* [master](https://github.com/prysmaticlabs/prysm/tree/master): This points to the latest stable release. It is ideal for most users.
-* [develop](https://github.com/prysmaticlabs/prysm/tree/develop): This is used for development, it contains the latest PRs. Developers should base their PRs on this branch.
+- **[`master`](https://github.com/prysmaticlabs/prysm/tree/master)** - This points to the latest stable release. It is ideal for most users.
+- **[`develop`](https://github.com/prysmaticlabs/prysm/tree/develop)** - This is used for development and contains the latest PRs. Developers should base their PRs on this branch.
 
-### Guide
-Want to get involved? Check out our [Contribution Guide](https://docs.prylabs.network/docs/contribute/contribution-guidelines/) to learn more!
+### 🛠 Contribution Guide
 
-## License
+Want to get involved? Check out our **[Contribution Guide](https://docs.prylabs.network/docs/contribute/contribution-guidelines/)** to learn more!
 
-[GNU General Public License v3.0](https://www.gnu.org/licenses/gpl-3.0.en.html)
+---
 
-## Legal Disclaimer
+## 📜 License
 
-[Terms of Use](/TERMS_OF_SERVICE.md)
+[![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0.en.html)  
+
+This project is licensed under the **GNU General Public License v3.0**.
+
+---
+
+## ⚖️ Legal Disclaimer
+
+📜 [Terms of Use](/TERMS_OF_SERVICE.md)

WORKSPACE

@@ -16,6 +16,34 @@ load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")
 
 rules_pkg_dependencies()
 
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "toolchains_protoc",
+    sha256 = "abb1540f8a9e045422730670ebb2f25b41fa56ca5a7cf795175a110a0a68f4ad",
+    strip_prefix = "toolchains_protoc-0.3.6",
+    url = "https://github.com/aspect-build/toolchains_protoc/releases/download/v0.3.6/toolchains_protoc-v0.3.6.tar.gz",
+)
+
+load("@toolchains_protoc//protoc:repositories.bzl", "rules_protoc_dependencies")
+
+rules_protoc_dependencies()
+
+load("@rules_proto//proto:repositories.bzl", "rules_proto_dependencies")
+
+rules_proto_dependencies()
+
+load("@bazel_features//:deps.bzl", "bazel_features_deps")
+
+bazel_features_deps()
+
+load("@toolchains_protoc//protoc:toolchain.bzl", "protoc_toolchains")
+
+protoc_toolchains(
+    name = "protoc_toolchains",
+    version = "v25.3",
+)
+
 HERMETIC_CC_TOOLCHAIN_VERSION = "v3.0.1"
 
 http_archive(
@@ -132,15 +160,15 @@ oci_register_toolchains(
 
 http_archive(
     name = "io_bazel_rules_go",
+    integrity = "sha256-JD8o94crTb2DFiJJR8nMAGdBAW95zIENB4cbI+JnrI4=",
     patch_args = ["-p1"],
     patches = [
         # Expose internals of go_test for custom build transitions.
         "//third_party:io_bazel_rules_go_test.patch",
     ],
-    sha256 = "80a98277ad1311dacd837f9b16db62887702e9f1d1c4c9f796d0121a46c8e184",
+    strip_prefix = "rules_go-cf3c3af34bd869b864f5f2b98e2f41c2b220d6c9",
     urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.46.0/rules_go-v0.46.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.46.0/rules_go-v0.46.0.zip",
+        "https://github.com/bazel-contrib/rules_go/archive/cf3c3af34bd869b864f5f2b98e2f41c2b220d6c9.tar.gz",
     ],
 )
 
@@ -182,7 +210,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()
 
 go_register_toolchains(
-    go_version = "1.22.4",
+    go_version = "1.24.0",
     nogo = "@//:nogo",
 )
 
@@ -227,7 +255,7 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.5.0-alpha.8"
+consensus_spec_version = "v1.5.0-beta.4"
 
 bls_test_version = "v0.1.1"
 
@@ -243,7 +271,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-BsGIbEyJuYrzhShGl0tHhR4lP5Qwno8R3k8a6YBR/DA=",
+    integrity = "sha256-QG0NUqaCvP5lKaKKwF/fmeICZVjONMlb7EE+MtYl0C0=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )
 
@@ -259,7 +287,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-DkdvhPP2KiqUOpwFXQIFDCWCwsUDIC/xhTBD+TZevm0=",
+    integrity = "sha256-8NQngTSSqzW/j3tOUi3r5h+94ChRbLNWTt7BOGqr4+E=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )
 
@@ -275,7 +303,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-vkZqV0HB8A2Uc56C1Us/p5G57iaHL+zw2No93Xt6M/4=",
+    integrity = "sha256-gFqxbaBnJ7dtdoj0zFbVrtlHv/bLNuWjrTHkyCAjFjI=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )
 
@@ -290,7 +318,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-D/HPAW61lKqjoWwl7N0XvhdX+67dCEFAy8JxVzqBGtU=",
+    integrity = "sha256-9paalF0POULpP2ga+4ouHSETKYrWNCUCZoJHPuFw06E=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -337,9 +365,9 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 """,
-    integrity = "sha256-b7ZTT+olF+VXEJYNTV5jggNtCkt9dOejm1i2VE+zy+0=",
-    strip_prefix = "holesky-874c199423ccd180607320c38cbaca05d9a1573a",
-    url = "https://github.com/eth-clients/holesky/archive/874c199423ccd180607320c38cbaca05d9a1573a.tar.gz",  # 2024-06-18
+    integrity = "sha256-YVFFrCmjoGZ3fXMWpsCpSsYbANy1grnqYwOLKIg2SsA=",
+    strip_prefix = "holesky-32a72e21c6e53c262f27d50dd540cb654517d03a",
+    url = "https://github.com/eth-clients/holesky/archive/32a72e21c6e53c262f27d50dd540cb654517d03a.tar.gz",  # 2025-03-17
 )
 
 http_archive(
@@ -353,9 +381,25 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 """,
-    integrity = "sha256-cY/UgpCcYEhQf7JefD65FI8tn/A+rAvKhcm2/qiVdqY=",
-    strip_prefix = "sepolia-f2c219a93c4491cee3d90c18f2f8e82aed850eab",
-    url = "https://github.com/eth-clients/sepolia/archive/f2c219a93c4491cee3d90c18f2f8e82aed850eab.tar.gz",  # 2024-09-19
+    integrity = "sha256-b5F7Wg9LLMqGRIpP2uqb/YsSFVn2ynzlV7g/Nb1EFLk=",
+    strip_prefix = "sepolia-562d9938f08675e9ba490a1dfba21fb05843f39f",
+    url = "https://github.com/eth-clients/sepolia/archive/562d9938f08675e9ba490a1dfba21fb05843f39f.tar.gz",  # 2025-03-17
+)
+
+http_archive(
+    name = "hoodi_testnet",
+    build_file_content = """
+filegroup(
+    name = "configs",
+    srcs = [
+        "metadata/config.yaml",
+    ],
+    visibility = ["//visibility:public"],
+)
+""",
+    integrity = "sha256-dPiEWUd8QvbYGwGtIm0QtCekitVLOLsW5rpQIGzz8PU=",
+    strip_prefix = "hoodi-828c2c940e1141092bd4bb979cef547ea926d272",
+    url = "https://github.com/eth-clients/hoodi/archive/828c2c940e1141092bd4bb979cef547ea926d272.tar.gz",
 )
 
 http_archive(
@@ -403,7 +447,7 @@ gometalinter_dependencies()
 
 load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
 
-gazelle_dependencies()
+gazelle_dependencies(go_sdk = "go_sdk")
 
 load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 

api/BUILD.bazel

@@ -2,11 +2,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = [
-        "constants.go",
-        "headers.go",
-        "jwt.go",
-    ],
+    srcs = ["jwt.go"],
     importpath = "github.com/prysmaticlabs/prysm/v5/api",
     visibility = ["//visibility:public"],
     deps = [

api/client/BUILD.bazel

@@ -4,17 +4,22 @@ go_library(
     name = "go_default_library",
     srcs = [
         "client.go",
-        "errors.go",
         "options.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/api/client",
     visibility = ["//visibility:public"],
-    deps = ["@com_github_pkg_errors//:go_default_library"],
+    deps = [
+        "//api/httputil:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
 )
 
 go_test(
     name = "go_default_test",
     srcs = ["client_test.go"],
     embed = [":go_default_library"],
-    deps = ["//testing/require:go_default_library"],
+    deps = [
+        "//api/httputil:go_default_library",
+        "//testing/require:go_default_library",
+    ],
 )

api/client/beacon/BUILD.bazel

@@ -3,61 +3,41 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
-        "checkpoint.go",
         "client.go",
         "doc.go",
         "health.go",
         "log.go",
+        "template.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/api/client/beacon",
     visibility = ["//visibility:public"],
     deps = [
         "//api/client:go_default_library",
         "//api/client/beacon/iface:go_default_library",
+        "//api/httputil:go_default_library",
         "//api/server:go_default_library",
         "//api/server/structs:go_default_library",
-        "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/state:go_default_library",
-        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
-        "//encoding/ssz/detect:go_default_library",
-        "//io/file:go_default_library",
         "//network/forks:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime/version:go_default_library",
-        "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@org_golang_x_mod//semver:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
     srcs = [
-        "checkpoint_test.go",
         "client_test.go",
         "health_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
-        "//api/client:go_default_library",
         "//api/client/beacon/testing:go_default_library",
-        "//beacon-chain/state:go_default_library",
-        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
-        "//consensus-types/primitives:go_default_library",
-        "//encoding/ssz/detect:go_default_library",
-        "//network/forks:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime/version:go_default_library",
+        "//api/httputil:go_default_library",
         "//testing/require:go_default_library",
-        "//testing/util:go_default_library",
-        "//time/slots:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
         "@org_uber_go_mock//gomock:go_default_library",
     ],
 )

api/client/beacon/checkpoint.go

@@ -1,276 +0,0 @@
-package beacon
-
-import (
-	"context"
-	"fmt"
-	"path"
-
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/pkg/errors"
-	base "github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v5/io/file"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
-	"github.com/sirupsen/logrus"
-	"golang.org/x/mod/semver"
-)
-
-var errCheckpointBlockMismatch = errors.New("mismatch between checkpoint sync state and block")
-
-// OriginData represents the BeaconState and ReadOnlySignedBeaconBlock necessary to start an empty Beacon Node
-// using Checkpoint Sync.
-type OriginData struct {
-	sb []byte
-	bb []byte
-	st state.BeaconState
-	b  interfaces.ReadOnlySignedBeaconBlock
-	vu *detect.VersionedUnmarshaler
-	br [32]byte
-	sr [32]byte
-}
-
-// SaveBlock saves the downloaded block to a unique file in the given path.
-// For readability and collision avoidance, the file name includes: type, config name, slot and root
-func (o *OriginData) SaveBlock(dir string) (string, error) {
-	blockPath := path.Join(dir, fname("block", o.vu, o.b.Block().Slot(), o.br))
-	return blockPath, file.WriteFile(blockPath, o.BlockBytes())
-}
-
-// SaveState saves the downloaded state to a unique file in the given path.
-// For readability and collision avoidance, the file name includes: type, config name, slot and root
-func (o *OriginData) SaveState(dir string) (string, error) {
-	statePath := path.Join(dir, fname("state", o.vu, o.st.Slot(), o.sr))
-	return statePath, file.WriteFile(statePath, o.StateBytes())
-}
-
-// StateBytes returns the ssz-encoded bytes of the downloaded BeaconState value.
-func (o *OriginData) StateBytes() []byte {
-	return o.sb
-}
-
-// BlockBytes returns the ssz-encoded bytes of the downloaded ReadOnlySignedBeaconBlock value.
-func (o *OriginData) BlockBytes() []byte {
-	return o.bb
-}
-
-func fname(prefix string, vu *detect.VersionedUnmarshaler, slot primitives.Slot, root [32]byte) string {
-	return fmt.Sprintf("%s_%s_%s_%d-%#x.ssz", prefix, vu.Config.ConfigName, version.String(vu.Fork), slot, root)
-}
-
-// DownloadFinalizedData downloads the most recently finalized state, and the block most recently applied to that state.
-// This pair can be used to initialize a new beacon node via checkpoint sync.
-func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, error) {
-	sb, err := client.GetState(ctx, IdFinalized)
-	if err != nil {
-		return nil, err
-	}
-	vu, err := detect.FromState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error detecting chain config for finalized state")
-	}
-
-	log.WithFields(logrus.Fields{
-		"name": vu.Config.ConfigName,
-		"fork": version.String(vu.Fork),
-	}).Info("Detected supported config in remote finalized state")
-
-	s, err := vu.UnmarshalBeaconState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error unmarshaling finalized state to correct version")
-	}
-
-	slot := s.LatestBlockHeader().Slot
-	bb, err := client.GetBlock(ctx, IdFromSlot(slot))
-	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by slot = %d", slot)
-	}
-	b, err := vu.UnmarshalBeaconBlock(bb)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
-	}
-	br, err := b.Block().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block")
-	}
-	bodyRoot, err := b.Block().Body().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block body")
-	}
-
-	sbr := bytesutil.ToBytes32(s.LatestBlockHeader().BodyRoot)
-	if sbr != bodyRoot {
-		return nil, errors.Wrapf(errCheckpointBlockMismatch, "state body root = %#x, block body root = %#x", sbr, bodyRoot)
-	}
-	sr, err := s.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to compute htr for finalized state at slot=%d", s.Slot())
-	}
-
-	log.
-		WithField("blockSlot", b.Block().Slot()).
-		WithField("stateSlot", s.Slot()).
-		WithField("stateRoot", hexutil.Encode(sr[:])).
-		WithField("blockRoot", hexutil.Encode(br[:])).
-		Info("Downloaded checkpoint sync state and block.")
-	return &OriginData{
-		st: s,
-		b:  b,
-		sb: sb,
-		bb: bb,
-		vu: vu,
-		br: br,
-		sr: sr,
-	}, nil
-}
-
-// WeakSubjectivityData represents the state root, block root and epoch of the BeaconState + ReadOnlySignedBeaconBlock
-// that falls at the beginning of the current weak subjectivity period. These values can be used to construct
-// a weak subjectivity checkpoint beacon node flag to be used for validation.
-type WeakSubjectivityData struct {
-	BlockRoot [32]byte
-	StateRoot [32]byte
-	Epoch     primitives.Epoch
-}
-
-// CheckpointString returns the standard string representation of a Checkpoint.
-// The format is a hex-encoded block root, followed by the epoch of the block, separated by a colon. For example:
-// "0x1c35540cac127315fabb6bf29181f2ae0de1a3fc909d2e76ba771e61312cc49a:74888"
-func (wsd *WeakSubjectivityData) CheckpointString() string {
-	return fmt.Sprintf("%#x:%d", wsd.BlockRoot, wsd.Epoch)
-}
-
-// ComputeWeakSubjectivityCheckpoint attempts to use the prysm weak_subjectivity api
-// to obtain the current weak_subjectivity checkpoint.
-// For non-prysm nodes, the same computation will be performed with extra steps,
-// using the head state downloaded from the beacon node api.
-func ComputeWeakSubjectivityCheckpoint(ctx context.Context, client *Client) (*WeakSubjectivityData, error) {
-	ws, err := client.GetWeakSubjectivity(ctx)
-	if err != nil {
-		// a 404/405 is expected if querying an endpoint that doesn't support the weak subjectivity checkpoint api
-		if !errors.Is(err, base.ErrNotOK) {
-			return nil, errors.Wrap(err, "unexpected API response for prysm-only weak subjectivity checkpoint API")
-		}
-		// fall back to vanilla Beacon Node API method
-		return computeBackwardsCompatible(ctx, client)
-	}
-	log.Printf("server weak subjectivity checkpoint response - epoch=%d, block_root=%#x, state_root=%#x", ws.Epoch, ws.BlockRoot, ws.StateRoot)
-	return ws, nil
-}
-
-const (
-	prysmMinimumVersion     = "v2.0.7"
-	prysmImplementationName = "Prysm"
-)
-
-// errUnsupportedPrysmCheckpointVersion indicates remote beacon node can't be used for checkpoint retrieval.
-var errUnsupportedPrysmCheckpointVersion = errors.New("node does not meet minimum version requirements for checkpoint retrieval")
-
-// for older endpoints or clients that do not support the weak_subjectivity api method
-// we gather the necessary data for a checkpoint sync by:
-// - inspecting the remote server's head state and computing the weak subjectivity epoch locally
-// - requesting the state at the first slot of the epoch
-// - using hash_tree_root(state.latest_block_header) to compute the block the state integrates
-// - requesting that block by its root
-func computeBackwardsCompatible(ctx context.Context, client *Client) (*WeakSubjectivityData, error) {
-	log.Print("falling back to generic checkpoint derivation, weak_subjectivity API not supported by server")
-	nv, err := client.GetNodeVersion(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to proceed with fallback method without confirming node version")
-	}
-	if nv.implementation == prysmImplementationName && semver.Compare(nv.semver, prysmMinimumVersion) < 0 {
-		return nil, errors.Wrapf(errUnsupportedPrysmCheckpointVersion, "%s < minimum (%s)", nv.semver, prysmMinimumVersion)
-	}
-	epoch, err := getWeakSubjectivityEpochFromHead(ctx, client)
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing weak subjectivity epoch via head state inspection")
-	}
-
-	// use first slot of the epoch for the state slot
-	slot, err := slots.EpochStart(epoch)
-	if err != nil {
-		return nil, errors.Wrapf(err, "error computing first slot of epoch=%d", epoch)
-	}
-
-	log.Printf("requesting checkpoint state at slot %d", slot)
-	// get the state at the first slot of the epoch
-	sb, err := client.GetState(ctx, IdFromSlot(slot))
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to request state by slot from api, slot=%d", slot)
-	}
-
-	// ConfigFork is used to unmarshal the BeaconState so we can read the block root in latest_block_header
-	vu, err := detect.FromState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error detecting chain config for beacon state")
-	}
-	log.Printf("detected supported config in checkpoint state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
-
-	s, err := vu.UnmarshalBeaconState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error using detected config fork to unmarshal state bytes")
-	}
-
-	// compute state and block roots
-	sr, err := s.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of state")
-	}
-
-	h := s.LatestBlockHeader()
-	h.StateRoot = sr[:]
-	br, err := h.HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error while computing block root using state data")
-	}
-
-	bb, err := client.GetBlock(ctx, IdFromRoot(br))
-	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by root = %d", br)
-	}
-	b, err := vu.UnmarshalBeaconBlock(bb)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
-	}
-	br, err = b.Block().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root for block obtained via root")
-	}
-
-	return &WeakSubjectivityData{
-		Epoch:     epoch,
-		BlockRoot: br,
-		StateRoot: sr,
-	}, nil
-}
-
-// this method downloads the head state, which can be used to find the correct chain config
-// and use prysm's helper methods to compute the latest weak subjectivity epoch.
-func getWeakSubjectivityEpochFromHead(ctx context.Context, client *Client) (primitives.Epoch, error) {
-	headBytes, err := client.GetState(ctx, IdHead)
-	if err != nil {
-		return 0, err
-	}
-	vu, err := detect.FromState(headBytes)
-	if err != nil {
-		return 0, errors.Wrap(err, "error detecting chain config for beacon state")
-	}
-	log.Printf("detected supported config in remote head state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
-	headState, err := vu.UnmarshalBeaconState(headBytes)
-	if err != nil {
-		return 0, errors.Wrap(err, "error unmarshaling state to correct version")
-	}
-
-	epoch, err := helpers.LatestWeakSubjectivityEpoch(ctx, headState, vu.Config)
-	if err != nil {
-		return 0, errors.Wrap(err, "error computing the weak subjectivity epoch from head state")
-	}
-
-	log.Printf("(computed client-side) weak subjectivity epoch = %d", epoch)
-	return epoch, nil
-}

api/client/beacon/client.go

@@ -11,11 +11,11 @@ import (
 	"regexp"
 	"sort"
 	"strconv"
-	"text/template"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/api/client"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	"github.com/prysmaticlabs/prysm/v5/api/server"
 	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -29,12 +29,13 @@ const (
 	getSignedBlockPath       = "/eth/v2/beacon/blocks"
 	getBlockRootPath         = "/eth/v1/beacon/blocks/{{.Id}}/root"
 	getForkForStatePath      = "/eth/v1/beacon/states/{{.Id}}/fork"
-	getWeakSubjectivityPath  = "/prysm/v1/beacon/weak_subjectivity"
 	getForkSchedulePath      = "/eth/v1/config/fork_schedule"
 	getConfigSpecPath        = "/eth/v1/config/spec"
 	getStatePath             = "/eth/v2/debug/beacon/states"
-	getNodeVersionPath       = "/eth/v1/node/version"
 	changeBLStoExecutionPath = "/eth/v1/beacon/pool/bls_to_execution_changes"
+
+	GetNodeVersionPath      = "/eth/v1/node/version"
+	GetWeakSubjectivityPath = "/prysm/v1/beacon/weak_subjectivity"
 )
 
 // StateOrBlockId represents the block_id / state_id parameters that several of the Eth Beacon API methods accept.
@@ -63,24 +64,8 @@ func IdFromSlot(s primitives.Slot) StateOrBlockId {
 	return StateOrBlockId(strconv.FormatUint(uint64(s), 10))
 }
 
-// idTemplate is used to create template functions that can interpolate StateOrBlockId values.
-func idTemplate(ts string) func(StateOrBlockId) string {
-	t := template.Must(template.New("").Parse(ts))
-	f := func(id StateOrBlockId) string {
-		b := bytes.NewBuffer(nil)
-		err := t.Execute(b, struct{ Id string }{Id: string(id)})
-		if err != nil {
-			panic(fmt.Sprintf("invalid idTemplate: %s", ts))
-		}
-		return b.String()
-	}
-	// run the template to ensure that it is valid
-	// this should happen load time (using package scoped vars) to ensure runtime errors aren't possible
-	_ = f(IdGenesis)
-	return f
-}
-
-func renderGetBlockPath(id StateOrBlockId) string {
+// RenderGetBlockPath formats a block id into a path for the GetBlock API endpoint.
+func RenderGetBlockPath(id StateOrBlockId) string {
 	return path.Join(getSignedBlockPath, string(id))
 }
 
@@ -104,7 +89,7 @@ func NewClient(host string, opts ...client.ClientOpt) (*Client, error) {
 // for the named identifiers.
 // The return value contains the ssz-encoded bytes.
 func (c *Client) GetBlock(ctx context.Context, blockId StateOrBlockId) ([]byte, error) {
-	blockPath := renderGetBlockPath(blockId)
+	blockPath := RenderGetBlockPath(blockId)
 	b, err := c.Get(ctx, blockPath, client.WithSSZEncoding())
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting state by id = %s", blockId)
@@ -112,8 +97,6 @@ func (c *Client) GetBlock(ctx context.Context, blockId StateOrBlockId) ([]byte,
 	return b, nil
 }
 
-var getBlockRootTpl = idTemplate(getBlockRootPath)
-
 // GetBlockRoot retrieves the hash_tree_root of the BeaconBlock for the given block id.
 // Block identifier can be one of: "head" (canonical head in node's view), "genesis", "finalized",
 // <slot>, <hex encoded blockRoot with 0x prefix>. Variables of type StateOrBlockId are exported by this package
@@ -136,8 +119,6 @@ func (c *Client) GetBlockRoot(ctx context.Context, blockId StateOrBlockId) ([32]
 	return bytesutil.ToBytes32(rs), nil
 }
 
-var getForkTpl = idTemplate(getForkForStatePath)
-
 // GetFork queries the Beacon Node API for the Fork from the state identified by stateId.
 // Block identifier can be one of: "head" (canonical head in node's view), "genesis", "finalized",
 // <slot>, <hex encoded blockRoot with 0x prefix>. Variables of type StateOrBlockId are exported by this package
@@ -195,12 +176,16 @@ type NodeVersion struct {
 	systemInfo     string
 }
 
+func (nv *NodeVersion) SetImplementation(impl string) {
+	nv.implementation = impl
+}
+
 var versionRE = regexp.MustCompile(`^(\w+)/(v\d+\.\d+\.\d+[-a-zA-Z0-9]*)\s*/?(.*)$`)
 
 func parseNodeVersion(v string) (*NodeVersion, error) {
 	groups := versionRE.FindStringSubmatch(v)
 	if len(groups) != 4 {
-		return nil, errors.Wrapf(client.ErrInvalidNodeVersion, "could not be parsed: %s", v)
+		return nil, errors.Wrapf(httputil.ErrInvalidNodeVersion, "could not be parsed: %s", v)
 	}
 	return &NodeVersion{
 		implementation: groups[1],
@@ -212,7 +197,7 @@ func parseNodeVersion(v string) (*NodeVersion, error) {
 // GetNodeVersion requests that the beacon node identify information about its implementation in a format
 // similar to a HTTP User-Agent field. ex: Lighthouse/v0.1.5 (Linux x86_64)
 func (c *Client) GetNodeVersion(ctx context.Context) (*NodeVersion, error) {
-	b, err := c.Get(ctx, getNodeVersionPath)
+	b, err := c.Get(ctx, GetNodeVersionPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting node version")
 	}
@@ -228,7 +213,8 @@ func (c *Client) GetNodeVersion(ctx context.Context) (*NodeVersion, error) {
 	return parseNodeVersion(d.Data.Version)
 }
 
-func renderGetStatePath(id StateOrBlockId) string {
+// RenderGetStatePath formats a state id into a path for the GetState API endpoint.
+func RenderGetStatePath(id StateOrBlockId) string {
 	return path.Join(getStatePath, string(id))
 }
 
@@ -246,13 +232,29 @@ func (c *Client) GetState(ctx context.Context, stateId StateOrBlockId) ([]byte,
 	return b, nil
 }
 
+// WeakSubjectivityData represents the state root, block root and epoch of the BeaconState + ReadOnlySignedBeaconBlock
+// that falls at the beginning of the current weak subjectivity period. These values can be used to construct
+// a weak subjectivity checkpoint beacon node flag to be used for validation.
+type WeakSubjectivityData struct {
+	BlockRoot [32]byte
+	StateRoot [32]byte
+	Epoch     primitives.Epoch
+}
+
+// CheckpointString returns the standard string representation of a Checkpoint.
+// The format is a hex-encoded block root, followed by the epoch of the block, separated by a colon. For example:
+// "0x1c35540cac127315fabb6bf29181f2ae0de1a3fc909d2e76ba771e61312cc49a:74888"
+func (wsd *WeakSubjectivityData) CheckpointString() string {
+	return fmt.Sprintf("%#x:%d", wsd.BlockRoot, wsd.Epoch)
+}
+
 // GetWeakSubjectivity calls a proposed API endpoint that is unique to prysm
 // This api method does the following:
 // - computes weak subjectivity epoch
 // - finds the highest non-skipped block preceding the epoch
 // - returns the htr of the found block and returns this + the value of state_root from the block
 func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData, error) {
-	body, err := c.Get(ctx, getWeakSubjectivityPath)
+	body, err := c.Get(ctx, GetWeakSubjectivityPath)
 	if err != nil {
 		return nil, err
 	}

api/client/beacon/client_test.go

@@ -4,7 +4,7 @@ import (
 	"net/url"
 	"testing"
 
-	"github.com/prysmaticlabs/prysm/v5/api/client"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
 
@@ -18,17 +18,17 @@ func TestParseNodeVersion(t *testing.T) {
 		{
 			name: "empty string",
 			v:    "",
-			err:  client.ErrInvalidNodeVersion,
+			err:  httputil.ErrInvalidNodeVersion,
 		},
 		{
 			name: "Prysm as the version string",
 			v:    "Prysm",
-			err:  client.ErrInvalidNodeVersion,
+			err:  httputil.ErrInvalidNodeVersion,
 		},
 		{
 			name: "semver only",
 			v:    "v2.0.6",
-			err:  client.ErrInvalidNodeVersion,
+			err:  httputil.ErrInvalidNodeVersion,
 		},
 		{
 			name: "complete version",
@@ -92,36 +92,36 @@ func TestValidHostname(t *testing.T) {
 		{
 			name:    "hostname without port",
 			hostArg: "mydomain.org",
-			err:     client.ErrMalformedHostname,
+			err:     httputil.ErrMalformedHostname,
 		},
 		{
 			name:    "hostname with port",
 			hostArg: "mydomain.org:3500",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://mydomain.org:3500/eth/v1/node/version",
 		},
 		{
 			name:    "https scheme, hostname with port",
 			hostArg: "https://mydomain.org:3500",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "https://mydomain.org:3500/eth/v1/node/version",
 		},
 		{
 			name:    "http scheme, hostname without port",
 			hostArg: "http://mydomain.org",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://mydomain.org/eth/v1/node/version",
 		},
 		{
 			name:    "http scheme, trailing slash, hostname without port",
 			hostArg: "http://mydomain.org/",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://mydomain.org/eth/v1/node/version",
 		},
 		{
 			name:    "http scheme, hostname with basic auth creds and no port",
 			hostArg: "http://username:pass@mydomain.org/",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://username:pass@mydomain.org/eth/v1/node/version",
 		},
 	}

api/client/beacon/template.go

@@ -0,0 +1,34 @@
+package beacon
+
+import (
+	"bytes"
+	"fmt"
+	"text/template"
+)
+
+type templateFn func(StateOrBlockId) string
+
+var getBlockRootTpl templateFn
+var getForkTpl templateFn
+
+func init() {
+	// idTemplate is used to create template functions that can interpolate StateOrBlockId values.
+	idTemplate := func(ts string) func(StateOrBlockId) string {
+		t := template.Must(template.New("").Parse(ts))
+		f := func(id StateOrBlockId) string {
+			b := bytes.NewBuffer(nil)
+			err := t.Execute(b, struct{ Id string }{Id: string(id)})
+			if err != nil {
+				panic(fmt.Sprintf("invalid idTemplate: %s", ts))
+			}
+			return b.String()
+		}
+		// run the template to ensure that it is valid
+		// this should happen load time (using package scoped vars) to ensure runtime errors aren't possible
+		_ = f(IdGenesis)
+		return f
+	}
+
+	getBlockRootTpl = idTemplate(getBlockRootPath)
+	getForkTpl = idTemplate(getForkForStatePath)
+}

api/client/builder/BUILD.bazel

@@ -11,9 +11,11 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/v5/api/client/builder",
     visibility = ["//visibility:public"],
     deps = [
-        "//api:go_default_library",
+        "//api/httputil:go_default_library",
+        "//api/server:go_default_library",
         "//api/server/structs:go_default_library",
         "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
@@ -25,10 +27,12 @@ go_library(
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
+        "@io_opentelemetry_go_contrib_instrumentation_net_http_otelhttp//:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )
@@ -42,6 +46,7 @@ go_test(
     data = glob(["testdata/**"]),
     embed = [":go_default_library"],
     deps = [
+        "//api/httputil:go_default_library",
         "//api/server/structs:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",

api/client/builder/bid.go

@@ -1,12 +1,12 @@
 package builder
 
 import (
-	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
 	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )
@@ -22,7 +22,6 @@ type SignedBid interface {
 // Bid is an interface describing the method set of a builder bid.
 type Bid interface {
 	Header() (interfaces.ExecutionData, error)
-	BlobKzgCommitments() ([][]byte, error)
 	Value() primitives.Wei
 	Pubkey() []byte
 	Version() int
@@ -31,6 +30,18 @@ type Bid interface {
 	HashTreeRootWith(hh *ssz.Hasher) error
 }
 
+// BidDeneb is an interface that exposes newly added kzg commitments on top of builder bid
+type BidDeneb interface {
+	Bid
+	BlobKzgCommitments() [][]byte
+}
+
+// BidElectra is an interface that exposes the newly added execution requests on top of the builder bid
+type BidElectra interface {
+	BidDeneb
+	ExecutionRequests() *v1.ExecutionRequests
+}
+
 type signedBuilderBid struct {
 	p *ethpb.SignedBuilderBid
 }
@@ -115,11 +126,6 @@ func (b builderBid) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeader(b.p.Header)
 }
 
-// BlobKzgCommitments --
-func (b builderBid) BlobKzgCommitments() ([][]byte, error) {
-	return [][]byte{}, errors.New("blob kzg commitments not available before Deneb")
-}
-
 // Version --
 func (b builderBid) Version() int {
 	return version.Bellatrix
@@ -169,11 +175,6 @@ func (b builderBidCapella) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeaderCapella(b.p.Header)
 }
 
-// BlobKzgCommitments --
-func (b builderBidCapella) BlobKzgCommitments() ([][]byte, error) {
-	return [][]byte{}, errors.New("blob kzg commitments not available before Deneb")
-}
-
 // Version --
 func (b builderBidCapella) Version() int {
 	return version.Capella
@@ -254,8 +255,8 @@ func (b builderBidDeneb) Header() (interfaces.ExecutionData, error) {
 }
 
 // BlobKzgCommitments --
-func (b builderBidDeneb) BlobKzgCommitments() ([][]byte, error) {
-	return b.p.BlobKzgCommitments, nil
+func (b builderBidDeneb) BlobKzgCommitments() [][]byte {
+	return b.p.BlobKzgCommitments
 }
 
 type signedBuilderBidDeneb struct {
@@ -290,3 +291,95 @@ func (b signedBuilderBidDeneb) Version() int {
 func (b signedBuilderBidDeneb) IsNil() bool {
 	return b.p == nil
 }
+
+type builderBidElectra struct {
+	p *ethpb.BuilderBidElectra
+}
+
+// WrappedBuilderBidElectra is a constructor which wraps a protobuf bid into an interface.
+func WrappedBuilderBidElectra(p *ethpb.BuilderBidElectra) (Bid, error) {
+	w := builderBidElectra{p: p}
+	if w.IsNil() {
+		return nil, consensus_types.ErrNilObjectWrapped
+	}
+	return w, nil
+}
+
+// Version --
+func (b builderBidElectra) Version() int {
+	return version.Electra
+}
+
+// Value --
+func (b builderBidElectra) Value() primitives.Wei {
+	return primitives.LittleEndianBytesToWei(b.p.Value)
+}
+
+// Pubkey --
+func (b builderBidElectra) Pubkey() []byte {
+	return b.p.Pubkey
+}
+
+// IsNil --
+func (b builderBidElectra) IsNil() bool {
+	return b.p == nil
+}
+
+// HashTreeRoot --
+func (b builderBidElectra) HashTreeRoot() ([32]byte, error) {
+	return b.p.HashTreeRoot()
+}
+
+// HashTreeRootWith --
+func (b builderBidElectra) HashTreeRootWith(hh *ssz.Hasher) error {
+	return b.p.HashTreeRootWith(hh)
+}
+
+// Header --
+func (b builderBidElectra) Header() (interfaces.ExecutionData, error) {
+	// We have to convert big endian to little endian because the value is coming from the execution layer.
+	return blocks.WrappedExecutionPayloadHeaderDeneb(b.p.Header)
+}
+
+// ExecutionRequests --
+func (b builderBidElectra) ExecutionRequests() *v1.ExecutionRequests {
+	return b.p.ExecutionRequests // does not copy
+}
+
+// BlobKzgCommitments --
+func (b builderBidElectra) BlobKzgCommitments() [][]byte {
+	return b.p.BlobKzgCommitments
+}
+
+type signedBuilderBidElectra struct {
+	p *ethpb.SignedBuilderBidElectra
+}
+
+// WrappedSignedBuilderBidElectra is a constructor which wraps a protobuf signed bit into an interface.
+func WrappedSignedBuilderBidElectra(p *ethpb.SignedBuilderBidElectra) (SignedBid, error) {
+	w := signedBuilderBidElectra{p: p}
+	if w.IsNil() {
+		return nil, consensus_types.ErrNilObjectWrapped
+	}
+	return w, nil
+}
+
+// Message --
+func (b signedBuilderBidElectra) Message() (Bid, error) {
+	return WrappedBuilderBidElectra(b.p.Message)
+}
+
+// Signature --
+func (b signedBuilderBidElectra) Signature() []byte {
+	return b.p.Signature
+}
+
+// Version --
+func (b signedBuilderBidElectra) Version() int {
+	return version.Electra
+}
+
+// IsNil --
+func (b signedBuilderBidElectra) IsNil() bool {
+	return b.p == nil
+}

api/client/builder/client.go

@@ -13,8 +13,9 @@ import (
 	"text/template"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -24,6 +25,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	log "github.com/sirupsen/logrus"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 const (
@@ -33,9 +35,14 @@ const (
 	postRegisterValidatorPath  = "/eth/v1/builder/validators"
 )
 
-var errMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
-var errMalformedRequest = errors.New("required request data are missing")
-var errNotBlinded = errors.New("submitted block is not blinded")
+var (
+	vrExample             = &ethpb.SignedValidatorRegistrationV1{}
+	vrSize                = vrExample.SizeSSZ()
+	errMalformedHostname  = errors.New("hostname must include port, separated by one colon, like example.com:3500")
+	errMalformedRequest   = errors.New("required request data are missing")
+	errNotBlinded         = errors.New("submitted block is not blinded")
+	errVersionUnsupported = errors.New("version is not supported")
+)
 
 // ClientOpt is a functional option for the Client type (http.Client wrapper)
 type ClientOpt func(*Client)
@@ -50,6 +57,12 @@ func WithObserver(m observer) ClientOpt {
 	}
 }
 
+func WithSSZ() ClientOpt {
+	return func(c *Client) {
+		c.sszEnabled = true
+	}
+}
+
 type requestLogger struct{}
 
 func (*requestLogger) observe(r *http.Request) (e error) {
@@ -93,9 +106,10 @@ type BuilderClient interface {
 
 // Client provides a collection of helper methods for calling Builder API endpoints.
 type Client struct {
-	hc      *http.Client
-	baseURL *url.URL
-	obvs    []observer
+	hc         *http.Client
+	baseURL    *url.URL
+	obvs       []observer
+	sszEnabled bool
 }
 
 // NewClient constructs a new client with the provided options (ex WithTimeout).
@@ -107,7 +121,7 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {
 		return nil, err
 	}
 	c := &Client{
-		hc:      &http.Client{},
+		hc:      &http.Client{Transport: otelhttp.NewTransport(http.DefaultTransport)},
 		baseURL: u,
 	}
 	for _, o := range opts {
@@ -137,7 +151,7 @@ func (c *Client) NodeURL() string {
 type reqOption func(*http.Request)
 
 // do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder.
-func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, err error) {
+func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, header http.Header, err error) {
 	ctx, span := trace.StartSpan(ctx, "builder.client.do")
 	defer func() {
 		tracing.AnnotateError(span, err)
@@ -176,11 +190,12 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 		err = non200Err(r)
 		return
 	}
-	res, err = io.ReadAll(r.Body)
+	res, err = io.ReadAll(io.LimitReader(r.Body, httputil.MaxBodySize))
 	if err != nil {
 		err = errors.Wrap(err, "error reading http response body from builder server")
 		return
 	}
+	header = r.Header
 	return
 }
 
@@ -210,48 +225,145 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 	if err != nil {
 		return nil, err
 	}
-	hb, err := c.do(ctx, http.MethodGet, path, nil)
+	var getOpts reqOption
+	if c.sszEnabled {
+		getOpts = func(r *http.Request) {
+			r.Header.Set("Accept", httputil.OctetStreamMediaType)
+		}
+	} else {
+		getOpts = func(r *http.Request) {
+			r.Header.Set("Accept", httputil.JsonMediaType)
+		}
+	}
+	data, header, err := c.do(ctx, http.MethodGet, path, nil, getOpts)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "error getting header from builder server")
 	}
-	v := &VersionResponse{}
-	if err := json.Unmarshal(hb, v); err != nil {
-		return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
+
+	bid, err := c.parseHeaderResponse(data, header)
+	if err != nil {
+		return nil, errors.Wrapf(
+			err,
+			"error rendering exec header template with slot=%d, parentHash=%#x, pubkey=%#x",
+			slot,
+			parentHash,
+			pubkey,
+		)
 	}
-	switch strings.ToLower(v.Version) {
-	case strings.ToLower(version.String(version.Deneb)):
-		hr := &ExecHeaderResponseDeneb{}
-		if err := json.Unmarshal(hb, hr); err != nil {
-			return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
+	return bid, nil
+}
+
+func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid, error) {
+	var versionHeader string
+	if c.sszEnabled || header.Get(httputil.VersionHeader) != "" {
+		versionHeader = header.Get(httputil.VersionHeader)
+	} else {
+		// If we don't have a version header, attempt to parse JSON for version
+		v := &VersionResponse{}
+		if err := json.Unmarshal(data, v); err != nil {
+			return nil, errors.Wrap(
+				err,
+				"error unmarshaling builder GetHeader response",
+			)
 		}
-		p, err := hr.ToProto()
-		if err != nil {
-			return nil, errors.Wrapf(err, "could not extract proto message from header")
-		}
-		return WrappedSignedBuilderBidDeneb(p)
-	case strings.ToLower(version.String(version.Capella)):
-		hr := &ExecHeaderResponseCapella{}
-		if err := json.Unmarshal(hb, hr); err != nil {
-			return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
-		}
-		p, err := hr.ToProto()
-		if err != nil {
-			return nil, errors.Wrapf(err, "could not extract proto message from header")
-		}
-		return WrappedSignedBuilderBidCapella(p)
-	case strings.ToLower(version.String(version.Bellatrix)):
-		hr := &ExecHeaderResponse{}
-		if err := json.Unmarshal(hb, hr); err != nil {
-			return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
-		}
-		p, err := hr.ToProto()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not extract proto message from header")
-		}
-		return WrappedSignedBuilderBid(p)
-	default:
-		return nil, fmt.Errorf("unsupported header version %s", strings.ToLower(v.Version))
+		versionHeader = strings.ToLower(v.Version)
 	}
+
+	ver, err := version.FromString(versionHeader)
+	if err != nil {
+		return nil, errors.Wrap(err, fmt.Sprintf("unsupported header version %s", versionHeader))
+	}
+
+	if ver >= version.Electra {
+		return c.parseHeaderElectra(data)
+	}
+	if ver >= version.Deneb {
+		return c.parseHeaderDeneb(data)
+	}
+	if ver >= version.Capella {
+		return c.parseHeaderCapella(data)
+	}
+	if ver >= version.Bellatrix {
+		return c.parseHeaderBellatrix(data)
+	}
+
+	return nil, fmt.Errorf("unsupported header version %s", versionHeader)
+}
+
+func (c *Client) parseHeaderElectra(data []byte) (SignedBid, error) {
+	if c.sszEnabled {
+		sb := &ethpb.SignedBuilderBidElectra{}
+		if err := sb.UnmarshalSSZ(data); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal SignedBuilderBidElectra SSZ")
+		}
+		return WrappedSignedBuilderBidElectra(sb)
+	}
+	hr := &ExecHeaderResponseElectra{}
+	if err := json.Unmarshal(data, hr); err != nil {
+		return nil, errors.Wrap(err, "could not unmarshal ExecHeaderResponseElectra JSON")
+	}
+	p, err := hr.ToProto()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert ExecHeaderResponseElectra to proto")
+	}
+	return WrappedSignedBuilderBidElectra(p)
+}
+
+func (c *Client) parseHeaderDeneb(data []byte) (SignedBid, error) {
+	if c.sszEnabled {
+		sb := &ethpb.SignedBuilderBidDeneb{}
+		if err := sb.UnmarshalSSZ(data); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal SignedBuilderBidDeneb SSZ")
+		}
+		return WrappedSignedBuilderBidDeneb(sb)
+	}
+	hr := &ExecHeaderResponseDeneb{}
+	if err := json.Unmarshal(data, hr); err != nil {
+		return nil, errors.Wrap(err, "could not unmarshal ExecHeaderResponseDeneb JSON")
+	}
+	p, err := hr.ToProto()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert ExecHeaderResponseDeneb to proto")
+	}
+	return WrappedSignedBuilderBidDeneb(p)
+}
+
+func (c *Client) parseHeaderCapella(data []byte) (SignedBid, error) {
+	if c.sszEnabled {
+		sb := &ethpb.SignedBuilderBidCapella{}
+		if err := sb.UnmarshalSSZ(data); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal SignedBuilderBidCapella SSZ")
+		}
+		return WrappedSignedBuilderBidCapella(sb)
+	}
+	hr := &ExecHeaderResponseCapella{}
+	if err := json.Unmarshal(data, hr); err != nil {
+		return nil, errors.Wrap(err, "could not unmarshal ExecHeaderResponseCapella JSON")
+	}
+	p, err := hr.ToProto()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert ExecHeaderResponseCapella to proto")
+	}
+	return WrappedSignedBuilderBidCapella(p)
+}
+
+func (c *Client) parseHeaderBellatrix(data []byte) (SignedBid, error) {
+	if c.sszEnabled {
+		sb := &ethpb.SignedBuilderBid{}
+		if err := sb.UnmarshalSSZ(data); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal SignedBuilderBid SSZ")
+		}
+		return WrappedSignedBuilderBid(sb)
+	}
+	hr := &ExecHeaderResponse{}
+	if err := json.Unmarshal(data, hr); err != nil {
+		return nil, errors.Wrap(err, "could not unmarshal ExecHeaderResponse JSON")
+	}
+	p, err := hr.ToProto()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert ExecHeaderResponse to proto")
+	}
+	return WrappedSignedBuilderBid(p)
 }
 
 // RegisterValidator encodes the SignedValidatorRegistrationV1 message to json (including hex-encoding the byte
@@ -266,70 +378,243 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 		tracing.AnnotateError(span, err)
 		return err
 	}
+
+	var (
+		body     []byte
+		err      error
+		postOpts reqOption
+	)
+	if c.sszEnabled {
+		postOpts = func(r *http.Request) {
+			r.Header.Set("Content-Type", httputil.OctetStreamMediaType)
+			r.Header.Set("Accept", httputil.OctetStreamMediaType)
+		}
+		body, err = sszValidatorRegisterRequest(svr)
+		if err != nil {
+			err := errors.Wrap(err, "error ssz encoding the SignedValidatorRegistration value body in RegisterValidator")
+			tracing.AnnotateError(span, err)
+			return err
+		}
+	} else {
+		postOpts = func(r *http.Request) {
+			r.Header.Set("Content-Type", httputil.JsonMediaType)
+			r.Header.Set("Accept", httputil.JsonMediaType)
+		}
+		body, err = jsonValidatorRegisterRequest(svr)
+		if err != nil {
+			err := errors.Wrap(err, "error json encoding the SignedValidatorRegistration value body in RegisterValidator")
+			tracing.AnnotateError(span, err)
+			return err
+		}
+	}
+
+	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), postOpts); err != nil {
+		return errors.Wrap(err, "do")
+	}
+	log.WithField("registrationCount", len(svr)).Debug("Successfully registered validator(s) on builder")
+	return nil
+}
+
+func jsonValidatorRegisterRequest(svr []*ethpb.SignedValidatorRegistrationV1) ([]byte, error) {
 	vs := make([]*structs.SignedValidatorRegistration, len(svr))
 	for i := 0; i < len(svr); i++ {
 		vs[i] = structs.SignedValidatorRegistrationFromConsensus(svr[i])
 	}
 	body, err := json.Marshal(vs)
 	if err != nil {
-		err := errors.Wrap(err, "error encoding the SignedValidatorRegistration value body in RegisterValidator")
-		tracing.AnnotateError(span, err)
-		return err
+		return nil, err
 	}
-
-	_, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body))
-	if err != nil {
-		return err
-	}
-	log.WithField("num_registrations", len(svr)).Info("successfully registered validator(s) on builder")
-	return nil
+	return body, nil
 }
 
-var errResponseVersionMismatch = errors.New("builder API response uses a different version than requested in " + api.VersionHeader + " header")
+func sszValidatorRegisterRequest(svr []*ethpb.SignedValidatorRegistrationV1) ([]byte, error) {
+	if uint64(len(svr)) > params.BeaconConfig().ValidatorRegistryLimit {
+		return nil, errors.Wrap(errMalformedRequest, "validator registry limit exceeded")
+	}
+	ssz := make([]byte, vrSize*len(svr))
+	for i, vr := range svr {
+		sszrep, err := vr.MarshalSSZ()
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to marshal validator registry ssz")
+		}
+		copy(ssz[i*vrSize:(i+1)*vrSize], sszrep)
+	}
+	return ssz, nil
+}
+
+var errResponseVersionMismatch = errors.New("builder API response uses a different version than requested in " + httputil.VersionHeader + " header")
+
+func getVersionsBlockToPayload(blockVersion int) (int, error) {
+	if blockVersion >= version.Deneb {
+		return version.Deneb, nil
+	}
+	if blockVersion == version.Capella {
+		return version.Capella, nil
+	}
+	if blockVersion == version.Bellatrix {
+		return version.Bellatrix, nil
+	}
+	return 0, errors.Wrapf(errVersionUnsupported, "block version %d", blockVersion)
+}
 
 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
 func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+	body, postOpts, err := c.buildBlindedBlockRequest(sb)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// post the blinded block - the execution payload response should contain the unblinded payload, along with the
+	// blobs bundle if it is post deneb.
+	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), postOpts)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "error posting the blinded block to the builder api")
+	}
+
+	ver, err := c.checkBlockVersion(data, header)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	expectedPayloadVer, err := getVersionsBlockToPayload(sb.Version())
+	if err != nil {
+		return nil, nil, err
+	}
+	gotPayloadVer, err := getVersionsBlockToPayload(ver)
+	if err != nil {
+		return nil, nil, err
+	}
+	if expectedPayloadVer != gotPayloadVer {
+		return nil, nil, errors.Wrapf(errResponseVersionMismatch, "expected payload version %d, got %d", expectedPayloadVer, gotPayloadVer)
+	}
+
+	ed, blobs, err := c.parseBlindedBlockResponse(data, ver)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return ed, blobs, nil
+}
+
+func (c *Client) checkBlockVersion(respBytes []byte, header http.Header) (int, error) {
+	var versionHeader string
+	if c.sszEnabled {
+		versionHeader = strings.ToLower(header.Get(httputil.VersionHeader))
+	} else {
+		// fallback to JSON-based version extraction
+		v := &VersionResponse{}
+		if err := json.Unmarshal(respBytes, v); err != nil {
+			return 0, errors.Wrapf(err, "error unmarshaling JSON version fallback")
+		}
+		versionHeader = strings.ToLower(v.Version)
+	}
+
+	ver, err := version.FromString(versionHeader)
+	if err != nil {
+		return 0, errors.Wrapf(err, "unsupported header version %s", versionHeader)
+	}
+
+	return ver, nil
+}
+
+// Helper: build request body for SubmitBlindedBlock
+func (c *Client) buildBlindedBlockRequest(sb interfaces.ReadOnlySignedBeaconBlock) ([]byte, reqOption, error) {
 	if !sb.IsBlinded() {
 		return nil, nil, errNotBlinded
 	}
 
-	// massage the proto struct type data into the api response type.
+	if c.sszEnabled {
+		body, err := sb.MarshalSSZ()
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not marshal SSZ for blinded block")
+		}
+		opt := func(r *http.Request) {
+			r.Header.Set(httputil.VersionHeader, version.String(sb.Version()))
+			r.Header.Set("Content-Type", httputil.OctetStreamMediaType)
+			r.Header.Set("Accept", httputil.OctetStreamMediaType)
+		}
+		return body, opt, nil
+	}
+
 	mj, err := structs.SignedBeaconBlockMessageJsoner(sb)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "error generating blinded beacon block post request")
 	}
-
 	body, err := json.Marshal(mj)
 	if err != nil {
-		return nil, nil, errors.Wrap(err, "error marshaling blinded block post request to json")
+		return nil, nil, errors.Wrap(err, "error marshaling blinded block to JSON")
 	}
-	postOpts := func(r *http.Request) {
-		r.Header.Add("Eth-Consensus-Version", version.String(sb.Version()))
-		r.Header.Set("Content-Type", api.JsonMediaType)
-		r.Header.Set("Accept", api.JsonMediaType)
+	opt := func(r *http.Request) {
+		r.Header.Set(httputil.VersionHeader, version.String(sb.Version()))
+		r.Header.Set("Content-Type", httputil.JsonMediaType)
+		r.Header.Set("Accept", httputil.JsonMediaType)
 	}
-	// post the blinded block - the execution payload response should contain the unblinded payload, along with the
-	// blobs bundle if it is post deneb.
-	rb, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), postOpts)
-	if err != nil {
-		return nil, nil, errors.Wrap(err, "error posting the blinded block to the builder api")
+	return body, opt, nil
+}
+
+// Helper: parse the response returned by SubmitBlindedBlock
+func (c *Client) parseBlindedBlockResponse(
+	respBytes []byte,
+	forkVersion int,
+) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+	if c.sszEnabled {
+		return c.parseBlindedBlockResponseSSZ(respBytes, forkVersion)
 	}
-	// ExecutionPayloadResponse parses just the outer container and the Value key, enabling it to use the .Value
-	// key to determine which underlying data type to use to finish the unmarshaling.
+	return c.parseBlindedBlockResponseJSON(respBytes, forkVersion)
+}
+
+func (c *Client) parseBlindedBlockResponseSSZ(
+	respBytes []byte,
+	forkVersion int,
+) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+	if forkVersion >= version.Deneb {
+		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundle{}
+		if err := payloadAndBlobs.UnmarshalSSZ(respBytes); err != nil {
+			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayloadDenebAndBlobsBundle SSZ")
+		}
+		ed, err := blocks.NewWrappedExecutionData(payloadAndBlobs.Payload)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "unable to wrap execution data for %s", version.String(forkVersion))
+		}
+		return ed, payloadAndBlobs.BlobsBundle, nil
+	} else if forkVersion >= version.Capella {
+		payload := &v1.ExecutionPayloadCapella{}
+		if err := payload.UnmarshalSSZ(respBytes); err != nil {
+			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayloadCapella SSZ")
+		}
+		ed, err := blocks.NewWrappedExecutionData(payload)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "unable to wrap execution data for %s", version.String(forkVersion))
+		}
+		return ed, nil, nil
+	} else if forkVersion >= version.Bellatrix {
+		payload := &v1.ExecutionPayload{}
+		if err := payload.UnmarshalSSZ(respBytes); err != nil {
+			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayload SSZ")
+		}
+		ed, err := blocks.NewWrappedExecutionData(payload)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "unable to wrap execution data for %s", version.String(forkVersion))
+		}
+		return ed, nil, nil
+	} else {
+		return nil, nil, fmt.Errorf("unsupported header version %s", version.String(forkVersion))
+	}
+}
+
+func (c *Client) parseBlindedBlockResponseJSON(
+	respBytes []byte,
+	forkVersion int,
+) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	ep := &ExecutionPayloadResponse{}
-	if err := json.Unmarshal(rb, ep); err != nil {
-		return nil, nil, errors.Wrap(err, "error unmarshaling the builder ExecutionPayloadResponse")
+	if err := json.Unmarshal(respBytes, ep); err != nil {
+		return nil, nil, errors.Wrap(err, "error unmarshaling ExecutionPayloadResponse")
 	}
-	if strings.ToLower(ep.Version) != version.String(sb.Version()) {
-		return nil, nil, errors.Wrapf(errResponseVersionMismatch, "req=%s, recv=%s", strings.ToLower(ep.Version), version.String(sb.Version()))
-	}
-	// This parses the rest of the response and returns the inner data field.
 	pp, err := ep.ParsePayload()
 	if err != nil {
-		return nil, nil, errors.Wrapf(err, "failed to parse execution payload from builder with version=%s", ep.Version)
+		return nil, nil, errors.Wrapf(err, "failed to parse payload with version=%s", ep.Version)
 	}
-	// Get the payload as a proto.Message so it can be wrapped as an execution payload interface.
 	pb, err := pp.PayloadProto()
 	if err != nil {
 		return nil, nil, err
@@ -338,11 +623,13 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 	if err != nil {
 		return nil, nil, err
 	}
+
+	// Check if it contains blobs
 	bb, ok := pp.(BlobBundler)
 	if ok {
 		bbpb, err := bb.BundleProto()
 		if err != nil {
-			return nil, nil, errors.Wrapf(err, "failed to extract blobs bundle from builder response with version=%s", ep.Version)
+			return nil, nil, errors.Wrapf(err, "failed to extract blobs bundle from version=%s", ep.Version)
 		}
 		return ed, bbpb, nil
 	}
@@ -353,12 +640,15 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 // response, and an error response may have an error message. This method will return a nil value for error in the
 // happy path, and an error with information about the server response body for a non-200 response.
 func (c *Client) Status(ctx context.Context) error {
-	_, err := c.do(ctx, http.MethodGet, getStatus, nil)
+	getOpts := func(r *http.Request) {
+		r.Header.Set("Accept", httputil.JsonMediaType)
+	}
+	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, getOpts)
 	return err
 }
 
 func non200Err(response *http.Response) error {
-	bodyBytes, err := io.ReadAll(response.Body)
+	bodyBytes, err := io.ReadAll(io.LimitReader(response.Body, httputil.MaxErrBodySize))
 	var errMessage ErrorMessage
 	var body string
 	if err != nil {
@@ -368,6 +658,18 @@ func non200Err(response *http.Response) error {
 	}
 	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
+	case http.StatusUnsupportedMediaType:
+		log.WithError(ErrUnsupportedMediaType).Debug(msg)
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
+		return errors.Wrap(ErrUnsupportedMediaType, errMessage.Message)
+	case http.StatusNotAcceptable:
+		log.WithError(ErrNotAcceptable).Debug(msg)
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
+		return errors.Wrap(ErrNotAcceptable, errMessage.Message)
 	case http.StatusNoContent:
 		log.WithError(ErrNoContent).Debug(msg)
 		return ErrNoContent

api/client/builder/client_test.go

@@ -8,15 +8,14 @@ import (
 	"io"
 	"net/http"
 	"net/url"
-	"strconv"
 	"testing"
 
 	"github.com/prysmaticlabs/go-bitfield"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -88,43 +87,90 @@ func TestClient_RegisterValidator(t *testing.T) {
 	ctx := context.Background()
 	expectedBody := `[{"message":{"fee_recipient":"0x0000000000000000000000000000000000000000","gas_limit":"23","timestamp":"42","pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}]`
 	expectedPath := "/eth/v1/builder/validators"
-	hc := &http.Client{
-		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
-			body, err := io.ReadAll(r.Body)
-			defer func() {
-				require.NoError(t, r.Body.Close())
-			}()
-			require.NoError(t, err)
-			require.Equal(t, expectedBody, string(body))
-			require.Equal(t, expectedPath, r.URL.Path)
-			require.Equal(t, http.MethodPost, r.Method)
-			return &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewBuffer(nil)),
-				Request:    r.Clone(ctx),
-			}, nil
-		}),
-	}
-	c := &Client{
-		hc:      hc,
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
-	reg := &eth.SignedValidatorRegistrationV1{
-		Message: &eth.ValidatorRegistrationV1{
-			FeeRecipient: ezDecode(t, params.BeaconConfig().EthBurnAddressHex),
-			GasLimit:     23,
-			Timestamp:    42,
-			Pubkey:       ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
-		},
-		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
-	}
-	require.NoError(t, c.RegisterValidator(ctx, []*eth.SignedValidatorRegistrationV1{reg}))
+	t.Run("JSON success", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
+				body, err := io.ReadAll(r.Body)
+				defer func() {
+					require.NoError(t, r.Body.Close())
+				}()
+				require.NoError(t, err)
+				require.Equal(t, expectedBody, string(body))
+				require.Equal(t, expectedPath, r.URL.Path)
+				require.Equal(t, http.MethodPost, r.Method)
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBuffer(nil)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		reg := &eth.SignedValidatorRegistrationV1{
+			Message: &eth.ValidatorRegistrationV1{
+				FeeRecipient: ezDecode(t, params.BeaconConfig().EthBurnAddressHex),
+				GasLimit:     23,
+				Timestamp:    42,
+				Pubkey:       ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+			},
+			Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+		}
+		require.NoError(t, c.RegisterValidator(ctx, []*eth.SignedValidatorRegistrationV1{reg}))
+	})
+	t.Run("SSZ success", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				body, err := io.ReadAll(r.Body)
+				defer func() {
+					require.NoError(t, r.Body.Close())
+				}()
+				require.NoError(t, err)
+				request := &eth.SignedValidatorRegistrationV1{}
+				itemBytes := body[:request.SizeSSZ()]
+				require.NoError(t, request.UnmarshalSSZ(itemBytes))
+				jsRequest := structs.SignedValidatorRegistrationFromConsensus(request)
+				js, err := json.Marshal([]*structs.SignedValidatorRegistration{jsRequest})
+				require.NoError(t, err)
+
+				require.Equal(t, expectedBody, string(js))
+				require.Equal(t, expectedPath, r.URL.Path)
+				require.Equal(t, http.MethodPost, r.Method)
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBuffer(nil)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		reg := &eth.SignedValidatorRegistrationV1{
+			Message: &eth.ValidatorRegistrationV1{
+				FeeRecipient: ezDecode(t, params.BeaconConfig().EthBurnAddressHex),
+				GasLimit:     23,
+				Timestamp:    42,
+				Pubkey:       ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+			},
+			Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+		}
+		require.NoError(t, c.RegisterValidator(ctx, []*eth.SignedValidatorRegistrationV1{reg}))
+	})
 }
 
 func TestClient_GetHeader(t *testing.T) {
 	ctx := context.Background()
 	expectedPath := "/eth/v1/builder/header/23/0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2/0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
-	var slot types.Slot = 23
+	var slot primitives.Slot = 23
 	parentHash := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
 	pubkey := ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
 	t.Run("server error", func(t *testing.T) {
@@ -174,6 +220,7 @@ func TestClient_GetHeader(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, expectedPath, r.URL.Path)
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponse)),
@@ -205,9 +252,56 @@ func TestClient_GetHeader(t *testing.T) {
 		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
 		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
 	})
+	t.Run("bellatrix ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				require.Equal(t, expectedPath, r.URL.Path)
+				epr := &ExecHeaderResponse{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponse), epr))
+				pro, err := epr.ToProto()
+				require.NoError(t, err)
+				ssz, err := pro.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "bellatrix")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedSig := ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505")
+		require.Equal(t, true, bytes.Equal(expectedSig, h.Signature()))
+		expectedTxRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.TransactionsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedTxRoot, withdrawalsRoot))
+		require.Equal(t, uint64(1), bidHeader.GasUsed())
+		// this matches the value in the testExampleHeaderResponse
+		bidStr := "652312848583266388373324160190187140051835877600158453279131187530910662656"
+		value, err := stringToUint256(bidStr)
+		require.NoError(t, err)
+		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
+		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
+	})
 	t.Run("capella", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
 				require.Equal(t, expectedPath, r.URL.Path)
 				return &http.Response{
 					StatusCode: http.StatusOK,
@@ -236,9 +330,52 @@ func TestClient_GetHeader(t *testing.T) {
 		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
 		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
 	})
+	t.Run("capella ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				require.Equal(t, expectedPath, r.URL.Path)
+				epr := &ExecHeaderResponseCapella{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponseCapella), epr))
+				pro, err := epr.ToProto()
+				require.NoError(t, err)
+				ssz, err := pro.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "capella")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+		bidStr := "652312848583266388373324160190187140051835877600158453279131187530910662656"
+		value, err := stringToUint256(bidStr)
+		require.NoError(t, err)
+		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
+		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
+	})
 	t.Run("deneb", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
 				require.Equal(t, expectedPath, r.URL.Path)
 				return &http.Response{
 					StatusCode: http.StatusOK,
@@ -267,9 +404,59 @@ func TestClient_GetHeader(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
 		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
-
-		kcgCommitments, err := bid.BlobKzgCommitments()
+		dbid, ok := bid.(builderBidDeneb)
+		require.Equal(t, true, ok)
+		kcgCommitments := dbid.BlobKzgCommitments()
+		require.Equal(t, len(kcgCommitments) > 0, true)
+		for i := range kcgCommitments {
+			require.Equal(t, len(kcgCommitments[i]) == 48, true)
+		}
+	})
+	t.Run("deneb ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				require.Equal(t, expectedPath, r.URL.Path)
+				epr := &ExecHeaderResponseDeneb{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponseDeneb), epr))
+				pro, err := epr.ToProto()
+				require.NoError(t, err)
+				ssz, err := pro.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "deneb")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
 		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+
+		bidStr := "652312848583266388373324160190187140051835877600158453279131187530910662656"
+		value, err := stringToUint256(bidStr)
+		require.NoError(t, err)
+		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
+		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
+		dbid, ok := bid.(builderBidDeneb)
+		require.Equal(t, true, ok)
+		kcgCommitments := dbid.BlobKzgCommitments()
 		require.Equal(t, len(kcgCommitments) > 0, true)
 		for i := range kcgCommitments {
 			require.Equal(t, len(kcgCommitments[i]) == 48, true)
@@ -291,7 +478,107 @@ func TestClient_GetHeader(t *testing.T) {
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}
 		_, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
-		require.ErrorContains(t, "could not extract proto message from header: too many blob commitments: 7", err)
+		require.ErrorContains(t, "could not convert ExecHeaderResponseDeneb to proto: too many blob commitments: 7", err)
+	})
+	t.Run("electra", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
+				require.Equal(t, expectedPath, r.URL.Path)
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseElectra)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+
+		bidStr := "652312848583266388373324160190187140051835877600158453279131187530910662656"
+		value, err := stringToUint256(bidStr)
+		require.NoError(t, err)
+		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
+		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
+		ebid, ok := bid.(builderBidElectra)
+		require.Equal(t, true, ok)
+		kcgCommitments := ebid.BlobKzgCommitments()
+		require.Equal(t, len(kcgCommitments) > 0, true)
+		for i := range kcgCommitments {
+			require.Equal(t, len(kcgCommitments[i]) == 48, true)
+		}
+		requests := ebid.ExecutionRequests()
+		require.Equal(t, 1, len(requests.Deposits))
+		require.Equal(t, 1, len(requests.Withdrawals))
+		require.Equal(t, 1, len(requests.Consolidations))
+
+	})
+	t.Run("electra ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				require.Equal(t, expectedPath, r.URL.Path)
+				epr := &ExecHeaderResponseElectra{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponseElectra), epr))
+				pro, err := epr.ToProto()
+				require.NoError(t, err)
+				ssz, err := pro.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "electra")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+
+		bidStr := "652312848583266388373324160190187140051835877600158453279131187530910662656"
+		value, err := stringToUint256(bidStr)
+		require.NoError(t, err)
+		require.Equal(t, 0, value.Int.Cmp(primitives.WeiToBigInt(bid.Value())))
+		require.Equal(t, bidStr, primitives.WeiToBigInt(bid.Value()).String())
+		ebid, ok := bid.(builderBidElectra)
+		require.Equal(t, true, ok)
+		kcgCommitments := ebid.BlobKzgCommitments()
+		require.Equal(t, len(kcgCommitments) > 0, true)
+		for i := range kcgCommitments {
+			require.Equal(t, len(kcgCommitments[i]) == 48, true)
+		}
+		requests := ebid.ExecutionRequests()
+		require.Equal(t, 1, len(requests.Deposits))
+		require.Equal(t, 1, len(requests.Withdrawals))
+		require.Equal(t, 1, len(requests.Consolidations))
+
 	})
 	t.Run("unsupported version", func(t *testing.T) {
 		hc := &http.Client{
@@ -321,8 +608,8 @@ func TestSubmitBlindedBlock(t *testing.T) {
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
 				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
-				require.Equal(t, "application/json", r.Header.Get("Content-Type"))
-				require.Equal(t, "application/json", r.Header.Get("Accept"))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayload)),
@@ -344,13 +631,53 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		require.Equal(t, fmt.Sprintf("%#x", bfpg.SSZBytes()), fmt.Sprintf("%#x", ep.BaseFeePerGas()))
 		require.Equal(t, uint64(1), ep.GasLimit())
 	})
+	t.Run("bellatrix ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				epr := &ExecutionPayloadResponse{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
+				ep := &ExecutionPayload{}
+				require.NoError(t, json.Unmarshal(epr.Data, ep))
+				pro, err := ep.ToProto()
+				require.NoError(t, err)
+				ssz, err := pro.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "bellatrix")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb)
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash()))
+		bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+		require.NoError(t, err)
+		require.Equal(t, fmt.Sprintf("%#x", bfpg.SSZBytes()), fmt.Sprintf("%#x", ep.BaseFeePerGas()))
+		require.Equal(t, uint64(1), ep.GasLimit())
+	})
 	t.Run("capella", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
-				require.Equal(t, "capella", r.Header.Get("Eth-Consensus-Version"))
-				require.Equal(t, "application/json", r.Header.Get("Content-Type"))
-				require.Equal(t, "application/json", r.Header.Get("Accept"))
+				require.Equal(t, "capella", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadCapella)),
@@ -370,7 +697,49 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 1, len(withdrawals))
 		assert.Equal(t, uint64(1), withdrawals[0].Index)
-		assert.Equal(t, types.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
+		assert.Equal(t, uint64(1), withdrawals[0].Amount)
+	})
+	t.Run("capella ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "capella", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				epr := &ExecutionPayloadResponse{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadCapella), epr))
+				ep := &ExecutionPayloadCapella{}
+				require.NoError(t, json.Unmarshal(epr.Data, ep))
+				pro, err := ep.ToProto()
+				require.NoError(t, err)
+				ssz, err := pro.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "capella")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockCapella(t))
+		require.NoError(t, err)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbb)
+		require.NoError(t, err)
+		withdrawals, err := ep.Withdrawals()
+		require.NoError(t, err)
+		require.Equal(t, 1, len(withdrawals))
+		assert.Equal(t, uint64(1), withdrawals[0].Index)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
@@ -379,9 +748,9 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
-				require.Equal(t, "deneb", r.Header.Get("Eth-Consensus-Version"))
-				require.Equal(t, "application/json", r.Header.Get("Content-Type"))
-				require.Equal(t, "application/json", r.Header.Get("Accept"))
+				require.Equal(t, "deneb", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
 				var req structs.SignedBlindedBeaconBlockDeneb
 				err := json.NewDecoder(r.Body).Decode(&req)
 				require.NoError(t, err)
@@ -409,7 +778,141 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 1, len(withdrawals))
 		assert.Equal(t, uint64(1), withdrawals[0].Index)
-		assert.Equal(t, types.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
+		assert.Equal(t, uint64(1), withdrawals[0].Amount)
+		require.NotNil(t, blobBundle)
+	})
+	t.Run("deneb ssz", func(t *testing.T) {
+		test := testSignedBlindedBeaconBlockDeneb(t)
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "deneb", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				epr := &ExecPayloadResponseDeneb{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDeneb), epr))
+				pro, blob, err := epr.ToProto()
+				require.NoError(t, err)
+				combined := &v1.ExecutionPayloadDenebAndBlobsBundle{
+					Payload:     pro,
+					BlobsBundle: blob,
+				}
+				ssz, err := combined.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "deneb")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbb, err := blocks.NewSignedBeaconBlock(test)
+		require.NoError(t, err)
+
+		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb)
+		require.NoError(t, err)
+		withdrawals, err := ep.Withdrawals()
+		require.NoError(t, err)
+		require.Equal(t, 1, len(withdrawals))
+		assert.Equal(t, uint64(1), withdrawals[0].Index)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
+		assert.Equal(t, uint64(1), withdrawals[0].Amount)
+		require.NotNil(t, blobBundle)
+	})
+	t.Run("electra", func(t *testing.T) {
+		test := testSignedBlindedBeaconBlockElectra(t)
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "electra", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.JsonMediaType, r.Header.Get("Accept"))
+				var req structs.SignedBlindedBeaconBlockElectra
+				err := json.NewDecoder(r.Body).Decode(&req)
+				require.NoError(t, err)
+				block, err := req.ToConsensus()
+				require.NoError(t, err)
+				require.DeepEqual(t, block, test)
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadDeneb)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+
+		sbb, err := blocks.NewSignedBeaconBlock(test)
+		require.NoError(t, err)
+
+		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb)
+		require.NoError(t, err)
+		withdrawals, err := ep.Withdrawals()
+		require.NoError(t, err)
+		require.Equal(t, 1, len(withdrawals))
+		assert.Equal(t, uint64(1), withdrawals[0].Index)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
+		assert.Equal(t, uint64(1), withdrawals[0].Amount)
+		require.NotNil(t, blobBundle)
+	})
+	t.Run("electra ssz", func(t *testing.T) {
+		test := testSignedBlindedBeaconBlockElectra(t)
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "electra", r.Header.Get(httputil.VersionHeader))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, httputil.OctetStreamMediaType, r.Header.Get("Accept"))
+				epr := &ExecPayloadResponseDeneb{}
+				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDeneb), epr))
+				pro, blob, err := epr.ToProto()
+				require.NoError(t, err)
+				combined := &v1.ExecutionPayloadDenebAndBlobsBundle{
+					Payload:     pro,
+					BlobsBundle: blob,
+				}
+				ssz, err := combined.MarshalSSZ()
+				require.NoError(t, err)
+				header := http.Header{}
+				header.Set(httputil.VersionHeader, "electra")
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Header:     header,
+					Body:       io.NopCloser(bytes.NewBuffer(ssz)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbb, err := blocks.NewSignedBeaconBlock(test)
+		require.NoError(t, err)
+
+		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb)
+		require.NoError(t, err)
+		withdrawals, err := ep.Withdrawals()
+		require.NoError(t, err)
+		require.Equal(t, 1, len(withdrawals))
+		assert.Equal(t, uint64(1), withdrawals[0].Index)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 		require.NotNil(t, blobBundle)
@@ -540,7 +1043,13 @@ func testSignedBlindedBeaconBlockBellatrix(t *testing.T) *eth.SignedBlindedBeaco
 				},
 				Deposits: []*eth.Deposit{
 					{
-						Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+						Proof: func() [][]byte {
+							b := make([][]byte, 33)
+							for i := range b {
+								b[i] = ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+							}
+							return b
+						}(),
 						Data: &eth.Deposit_Data{
 							PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
 							WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -559,8 +1068,8 @@ func testSignedBlindedBeaconBlockBellatrix(t *testing.T) *eth.SignedBlindedBeaco
 					},
 				},
 				SyncAggregate: &eth.SyncAggregate{
-					SyncCommitteeSignature: make([]byte, 48),
-					SyncCommitteeBits:      bitfield.Bitvector512{0x01},
+					SyncCommitteeSignature: make([]byte, 96),
+					SyncCommitteeBits:      make(bitfield.Bitvector512, 64),
 				},
 				ExecutionPayloadHeader: &v1.ExecutionPayloadHeader{
 					ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -574,7 +1083,7 @@ func testSignedBlindedBeaconBlockBellatrix(t *testing.T) *eth.SignedBlindedBeaco
 					GasUsed:          1,
 					Timestamp:        1,
 					ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-					BaseFeePerGas:    []byte(strconv.FormatUint(1, 10)),
+					BaseFeePerGas:    ezDecode(t, "0x4523128485832663883733241601901871400518358776001584532791311875"),
 					BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 					TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 				},
@@ -682,7 +1191,13 @@ func testSignedBlindedBeaconBlockCapella(t *testing.T) *eth.SignedBlindedBeaconB
 				},
 				Deposits: []*eth.Deposit{
 					{
-						Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+						Proof: func() [][]byte {
+							b := make([][]byte, 33)
+							for i := range b {
+								b[i] = ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+							}
+							return b
+						}(),
 						Data: &eth.Deposit_Data{
 							PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
 							WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -701,8 +1216,8 @@ func testSignedBlindedBeaconBlockCapella(t *testing.T) *eth.SignedBlindedBeaconB
 					},
 				},
 				SyncAggregate: &eth.SyncAggregate{
-					SyncCommitteeSignature: make([]byte, 48),
-					SyncCommitteeBits:      bitfield.Bitvector512{0x01},
+					SyncCommitteeSignature: make([]byte, 96),
+					SyncCommitteeBits:      make(bitfield.Bitvector512, 64),
 				},
 				ExecutionPayloadHeader: &v1.ExecutionPayloadHeaderCapella{
 					ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -716,7 +1231,7 @@ func testSignedBlindedBeaconBlockCapella(t *testing.T) *eth.SignedBlindedBeaconB
 					GasUsed:          1,
 					Timestamp:        1,
 					ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-					BaseFeePerGas:    []byte(strconv.FormatUint(1, 10)),
+					BaseFeePerGas:    ezDecode(t, "0x4523128485832663883733241601901871400518358776001584532791311875"),
 					BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 					TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 					WithdrawalsRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -829,7 +1344,13 @@ func testSignedBlindedBeaconBlockDeneb(t *testing.T) *eth.SignedBlindedBeaconBlo
 				},
 				Deposits: []*eth.Deposit{
 					{
-						Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+						Proof: func() [][]byte {
+							b := make([][]byte, 33)
+							for i := range b {
+								b[i] = ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+							}
+							return b
+						}(),
 						Data: &eth.Deposit_Data{
 							PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
 							WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -876,6 +1397,163 @@ func testSignedBlindedBeaconBlockDeneb(t *testing.T) *eth.SignedBlindedBeaconBlo
 	}
 }
 
+func testSignedBlindedBeaconBlockElectra(t *testing.T) *eth.SignedBlindedBeaconBlockElectra {
+	basebytes, err := bytesutil.Uint256ToSSZBytes("14074904626401341155369551180448584754667373453244490859944217516317499064576")
+	if err != nil {
+		log.Error(err)
+	}
+	return &eth.SignedBlindedBeaconBlockElectra{
+		Message: &eth.BlindedBeaconBlockElectra{
+			Slot:          1,
+			ProposerIndex: 1,
+			ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			Body: &eth.BlindedBeaconBlockBodyElectra{
+				RandaoReveal: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+				Eth1Data: &eth.Eth1Data{
+					DepositRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					DepositCount: 1,
+					BlockHash:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+				Graffiti: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				ProposerSlashings: []*eth.ProposerSlashing{
+					{
+						Header_1: &eth.SignedBeaconBlockHeader{
+							Header: &eth.BeaconBlockHeader{
+								Slot:          1,
+								ProposerIndex: 1,
+								ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+						Header_2: &eth.SignedBeaconBlockHeader{
+							Header: &eth.BeaconBlockHeader{
+								Slot:          1,
+								ProposerIndex: 1,
+								ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+				},
+				AttesterSlashings: []*eth.AttesterSlashingElectra{
+					{
+						Attestation_1: &eth.IndexedAttestationElectra{
+							AttestingIndices: []uint64{1},
+							Data: &eth.AttestationData{
+								Slot:            1,
+								CommitteeIndex:  1,
+								BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Source: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Target: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+						Attestation_2: &eth.IndexedAttestationElectra{
+							AttestingIndices: []uint64{1},
+							Data: &eth.AttestationData{
+								Slot:            1,
+								CommitteeIndex:  1,
+								BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Source: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Target: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+				},
+				Attestations: []*eth.AttestationElectra{
+					{
+						AggregationBits: bitfield.Bitlist{0x01},
+						Data: &eth.AttestationData{
+							Slot:            1,
+							CommitteeIndex:  1,
+							BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							Source: &eth.Checkpoint{
+								Epoch: 1,
+								Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Target: &eth.Checkpoint{
+								Epoch: 1,
+								Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+						},
+						CommitteeBits: make(bitfield.Bitvector64, 8),
+						Signature:     ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+					},
+				},
+				Deposits: []*eth.Deposit{
+					{
+						Proof: func() [][]byte {
+							b := make([][]byte, 33)
+							for i := range b {
+								b[i] = ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+							}
+							return b
+						}(),
+						Data: &eth.Deposit_Data{
+							PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+							WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							Amount:                1,
+							Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+				},
+				VoluntaryExits: []*eth.SignedVoluntaryExit{
+					{
+						Exit: &eth.VoluntaryExit{
+							Epoch:          1,
+							ValidatorIndex: 1,
+						},
+						Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+					},
+				},
+				SyncAggregate: &eth.SyncAggregate{
+					SyncCommitteeSignature: make([]byte, 96),
+					SyncCommitteeBits:      ezDecode(t, "0x6451e9f951ebf05edc01de67e593484b672877054f055903ff0df1a1a945cf30ca26bb4d4b154f94a1bc776bcf5d0efb3603e1f9b8ee2499ccdcfe2a18cef458"),
+				},
+				ExecutionRequests: &v1.ExecutionRequests{},
+				ExecutionPayloadHeader: &v1.ExecutionPayloadHeaderDeneb{
+					ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
+					StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+					PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BlockNumber:      1,
+					GasLimit:         1,
+					GasUsed:          1,
+					Timestamp:        1,
+					ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BaseFeePerGas:    basebytes,
+					BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					WithdrawalsRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BlobGasUsed:      1,
+					ExcessBlobGas:    2,
+				},
+			},
+		},
+		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+	}
+}
+
 func TestRequestLogger(t *testing.T) {
 	wo := WithObserver(&requestLogger{})
 	c, err := NewClient("localhost:3500", wo)

api/client/builder/errors.go

@@ -15,3 +15,9 @@ var ErrBadRequest = errors.Wrap(ErrNotOK, "recv 400 BadRequest response from API
 // ErrNoContent specifically means that a '204 - No Content' response was received from the API.
 // Typically, a 204 is a success but in this case for the Header API means No header is available
 var ErrNoContent = errors.New("recv 204 no content response from API, No header is available")
+
+// ErrUnsupportedMediaType specifically means that a '415 - Unsupported Media Type' was received from the API.
+var ErrUnsupportedMediaType = errors.Wrap(ErrNotOK, "The media type in \"Content-Type\" header is unsupported, and the request has been rejected. This occurs when a HTTP request supplies a payload in a content-type that the server is not able to handle.")
+
+// ErrNotAcceptable specifically means that a '406 - Not Acceptable' was received from the API.
+var ErrNotAcceptable = errors.Wrap(ErrNotOK, "The accept header value is not acceptable")

api/client/builder/types.go

@@ -5,12 +5,15 @@ import (
 	"fmt"
 	"math/big"
 	"strconv"
+	"strings"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/api/server"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/math"
@@ -413,54 +416,10 @@ func FromProtoDeneb(payload *v1.ExecutionPayloadDeneb) (ExecutionPayloadDeneb, e
 	}, nil
 }
 
-var errInvalidTypeConversion = errors.New("unable to translate between api and foreign type")
-
-// ExecutionPayloadResponseFromData converts an ExecutionData interface value to a payload response.
-// This involves serializing the execution payload value so that the abstract payload envelope can be used.
-func ExecutionPayloadResponseFromData(ed interfaces.ExecutionData, bundle *v1.BlobsBundle) (*ExecutionPayloadResponse, error) {
-	pb := ed.Proto()
-	var data interface{}
-	var err error
-	var ver string
-	switch pbStruct := pb.(type) {
-	case *v1.ExecutionPayload:
-		ver = version.String(version.Bellatrix)
-		data, err = FromProto(pbStruct)
-		if err != nil {
-			return nil, errors.Wrap(err, "failed to convert a Bellatrix ExecutionPayload to an API response")
-		}
-	case *v1.ExecutionPayloadCapella:
-		ver = version.String(version.Capella)
-		data, err = FromProtoCapella(pbStruct)
-		if err != nil {
-			return nil, errors.Wrap(err, "failed to convert a Capella ExecutionPayload to an API response")
-		}
-	case *v1.ExecutionPayloadDeneb:
-		ver = version.String(version.Deneb)
-		payloadStruct, err := FromProtoDeneb(pbStruct)
-		if err != nil {
-			return nil, errors.Wrap(err, "failed to convert a Deneb ExecutionPayload to an API response")
-		}
-		data = &ExecutionPayloadDenebAndBlobsBundle{
-			ExecutionPayload: &payloadStruct,
-			BlobsBundle:      FromBundleProto(bundle),
-		}
-	default:
-		return nil, errInvalidTypeConversion
-	}
-	encoded, err := json.Marshal(data)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to marshal execution payload version=%s", ver)
-	}
-	return &ExecutionPayloadResponse{
-		Version: ver,
-		Data:    encoded,
-	}, nil
-}
-
 // ExecHeaderResponseCapella is the response of builder API /eth/v1/builder/header/{slot}/{parent_hash}/{pubkey} for Capella.
 type ExecHeaderResponseCapella struct {
-	Data struct {
+	Version string `json:"version"`
+	Data    struct {
 		Signature hexutil.Bytes      `json:"signature"`
 		Message   *BuilderBidCapella `json:"message"`
 	} `json:"data"`
@@ -604,17 +563,25 @@ type BlobBundler interface {
 	BundleProto() (*v1.BlobsBundle, error)
 }
 
+// ParsedExecutionRequests can retrieve the underlying execution requests for the given execution payload response.
+type ParsedExecutionRequests interface {
+	ExecutionRequestsProto() (*v1.ExecutionRequests, error)
+}
+
 func (r *ExecutionPayloadResponse) ParsePayload() (ParsedPayload, error) {
 	var toProto ParsedPayload
-	switch r.Version {
-	case version.String(version.Bellatrix):
-		toProto = &ExecutionPayload{}
-	case version.String(version.Capella):
-		toProto = &ExecutionPayloadCapella{}
-	case version.String(version.Deneb):
+	v, err := version.FromString(strings.ToLower(r.Version))
+	if err != nil {
+		return nil, errors.Wrap(err, fmt.Sprintf("unsupported version %s", strings.ToLower(r.Version)))
+	}
+	if v >= version.Deneb {
 		toProto = &ExecutionPayloadDenebAndBlobsBundle{}
-	default:
-		return nil, consensusblocks.ErrUnsupportedVersion
+	} else if v >= version.Capella {
+		toProto = &ExecutionPayloadCapella{}
+	} else if v >= version.Bellatrix {
+		toProto = &ExecutionPayload{}
+	} else {
+		return nil, fmt.Errorf("unsupported version %s", strings.ToLower(r.Version))
 	}
 
 	if err := json.Unmarshal(r.Data, toProto); err != nil {
@@ -989,7 +956,8 @@ func (ch *BLSToExecutionChange) MarshalJSON() ([]byte, error) {
 
 // ExecHeaderResponseDeneb is the header response for builder API /eth/v1/builder/header/{slot}/{parent_hash}/{pubkey}.
 type ExecHeaderResponseDeneb struct {
-	Data struct {
+	Version string `json:"version"`
+	Data    struct {
 		Signature hexutil.Bytes    `json:"signature"`
 		Message   *BuilderBidDeneb `json:"message"`
 	} `json:"data"`
@@ -1013,7 +981,7 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 	if err != nil {
 		return nil, err
 	}
-	if len(bb.BlobKzgCommitments) > fieldparams.MaxBlobsPerBlock {
+	if len(bb.BlobKzgCommitments) > params.BeaconConfig().DeprecatedMaxBlobsPerBlock {
 		return nil, fmt.Errorf("too many blob commitments: %d", len(bb.BlobKzgCommitments))
 	}
 	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
@@ -1306,6 +1274,208 @@ func (p *ExecutionPayloadDeneb) ToProto() (*v1.ExecutionPayloadDeneb, error) {
 	}, nil
 }
 
+// ExecHeaderResponseElectra is the header response for builder API /eth/v1/builder/header/{slot}/{parent_hash}/{pubkey}.
+type ExecHeaderResponseElectra struct {
+	Version string `json:"version"`
+	Data    struct {
+		Signature hexutil.Bytes      `json:"signature"`
+		Message   *BuilderBidElectra `json:"message"`
+	} `json:"data"`
+}
+
+// ToProto creates a SignedBuilderBidElectra Proto from ExecHeaderResponseElectra.
+func (ehr *ExecHeaderResponseElectra) ToProto() (*eth.SignedBuilderBidElectra, error) {
+	bb, err := ehr.Data.Message.ToProto()
+	if err != nil {
+		return nil, err
+	}
+	return &eth.SignedBuilderBidElectra{
+		Message:   bb,
+		Signature: bytesutil.SafeCopyBytes(ehr.Data.Signature),
+	}, nil
+}
+
+// ToProto creates a BuilderBidElectra Proto from BuilderBidElectra.
+func (bb *BuilderBidElectra) ToProto() (*eth.BuilderBidElectra, error) {
+	header, err := bb.Header.ToProto()
+	if err != nil {
+		return nil, err
+	}
+	if len(bb.BlobKzgCommitments) > params.BeaconConfig().MaxBlobsPerBlockByVersion(version.Electra) {
+		return nil, fmt.Errorf("blob commitment count %d exceeds the maximum %d", len(bb.BlobKzgCommitments), params.BeaconConfig().MaxBlobsPerBlockByVersion(version.Electra))
+	}
+	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
+	for i, commit := range bb.BlobKzgCommitments {
+		if len(commit) != fieldparams.BLSPubkeyLength {
+			return nil, fmt.Errorf("commitment length %d is not %d", len(commit), fieldparams.BLSPubkeyLength)
+		}
+		kzgCommitments[i] = bytesutil.SafeCopyBytes(commit)
+	}
+	// post electra execution requests should not be nil, if no requests exist use an empty request
+	if bb.ExecutionRequests == nil {
+		return nil, errors.New("bid contains nil execution requests")
+	}
+	executionRequests, err := bb.ExecutionRequests.ToProto()
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to convert ExecutionRequests")
+	}
+	return &eth.BuilderBidElectra{
+		Header:             header,
+		BlobKzgCommitments: kzgCommitments,
+		ExecutionRequests:  executionRequests,
+		// Note that SSZBytes() reverses byte order for the little-endian representation.
+		// Uint256.Bytes() is big-endian, SSZBytes takes this value and reverses it.
+		Value:  bytesutil.SafeCopyBytes(bb.Value.SSZBytes()),
+		Pubkey: bytesutil.SafeCopyBytes(bb.Pubkey),
+	}, nil
+}
+
+// ExecutionRequestsV1 is a wrapper for different execution requests
+type ExecutionRequestsV1 struct {
+	Deposits       []*DepositRequestV1       `json:"deposits"`
+	Withdrawals    []*WithdrawalRequestV1    `json:"withdrawals"`
+	Consolidations []*ConsolidationRequestV1 `json:"consolidations"`
+}
+
+func (er *ExecutionRequestsV1) ToProto() (*v1.ExecutionRequests, error) {
+	if uint64(len(er.Deposits)) > params.BeaconConfig().MaxDepositRequestsPerPayload {
+		return nil, fmt.Errorf("deposit requests count %d exceeds the maximum %d", len(er.Deposits), params.BeaconConfig().MaxDepositRequestsPerPayload)
+	}
+	deposits := make([]*v1.DepositRequest, len(er.Deposits))
+	for i, dep := range er.Deposits {
+		d, err := dep.ToProto()
+		if err != nil {
+			return nil, err
+		}
+		deposits[i] = d
+	}
+	if uint64(len(er.Withdrawals)) > params.BeaconConfig().MaxWithdrawalRequestsPerPayload {
+		return nil, fmt.Errorf("withdrawal requests count %d exceeds the maximum %d", len(er.Withdrawals), params.BeaconConfig().MaxWithdrawalRequestsPerPayload)
+	}
+	withdrawals := make([]*v1.WithdrawalRequest, len(er.Withdrawals))
+	for i, wr := range er.Withdrawals {
+		w, err := wr.ToProto()
+		if err != nil {
+			return nil, err
+		}
+		withdrawals[i] = w
+	}
+	if uint64(len(er.Consolidations)) > params.BeaconConfig().MaxConsolidationsRequestsPerPayload {
+		return nil, fmt.Errorf("consolidation requests count %d exceeds the maximum %d", len(er.Consolidations), params.BeaconConfig().MaxConsolidationsRequestsPerPayload)
+	}
+	consolidations := make([]*v1.ConsolidationRequest, len(er.Consolidations))
+	for i, con := range er.Consolidations {
+		c, err := con.ToProto()
+		if err != nil {
+			return nil, err
+		}
+		consolidations[i] = c
+	}
+	return &v1.ExecutionRequests{
+		Deposits:       deposits,
+		Withdrawals:    withdrawals,
+		Consolidations: consolidations,
+	}, nil
+}
+
+// BuilderBidElectra is a field of ExecHeaderResponseElectra.
+type BuilderBidElectra struct {
+	Header             *ExecutionPayloadHeaderDeneb `json:"header"`
+	BlobKzgCommitments []hexutil.Bytes              `json:"blob_kzg_commitments"`
+	ExecutionRequests  *ExecutionRequestsV1         `json:"execution_requests"`
+	Value              Uint256                      `json:"value"`
+	Pubkey             hexutil.Bytes                `json:"pubkey"`
+}
+
+// WithdrawalRequestV1 is a field of ExecutionRequestsV1.
+type WithdrawalRequestV1 struct {
+	SourceAddress   hexutil.Bytes `json:"source_address"`
+	ValidatorPubkey hexutil.Bytes `json:"validator_pubkey"`
+	Amount          Uint256       `json:"amount"`
+}
+
+func (wr *WithdrawalRequestV1) ToProto() (*v1.WithdrawalRequest, error) {
+	srcAddress, err := bytesutil.DecodeHexWithLength(wr.SourceAddress.String(), common.AddressLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "source_address")
+	}
+	pubkey, err := bytesutil.DecodeHexWithLength(wr.ValidatorPubkey.String(), fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "validator_pubkey")
+	}
+
+	return &v1.WithdrawalRequest{
+		SourceAddress:   srcAddress,
+		ValidatorPubkey: pubkey,
+		Amount:          wr.Amount.Uint64(),
+	}, nil
+}
+
+// DepositRequestV1 is a field of ExecutionRequestsV1.
+type DepositRequestV1 struct {
+	PubKey hexutil.Bytes `json:"pubkey"`
+	// withdrawalCredentials: DATA, 32 Bytes
+	WithdrawalCredentials hexutil.Bytes `json:"withdrawal_credentials"`
+	// amount: QUANTITY, 64 Bits
+	Amount Uint256 `json:"amount"`
+	// signature: DATA, 96 Bytes
+	Signature hexutil.Bytes `json:"signature"`
+	// index: QUANTITY, 64 Bits
+	Index Uint256 `json:"index"`
+}
+
+func (dr *DepositRequestV1) ToProto() (*v1.DepositRequest, error) {
+	pubkey, err := bytesutil.DecodeHexWithLength(dr.PubKey.String(), fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "pubkey")
+	}
+	wc, err := bytesutil.DecodeHexWithLength(dr.WithdrawalCredentials.String(), fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "withdrawal_credentials")
+	}
+	sig, err := bytesutil.DecodeHexWithLength(dr.Signature.String(), fieldparams.BLSSignatureLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "signature")
+	}
+	return &v1.DepositRequest{
+		Pubkey:                pubkey,
+		WithdrawalCredentials: wc,
+		Amount:                dr.Amount.Uint64(),
+		Signature:             sig,
+		Index:                 dr.Index.Uint64(),
+	}, nil
+}
+
+// ConsolidationRequestV1 is a field of ExecutionRequestsV1.
+type ConsolidationRequestV1 struct {
+	// sourceAddress: DATA, 20 Bytes
+	SourceAddress hexutil.Bytes `json:"source_address"`
+	// sourcePubkey: DATA, 48 Bytes
+	SourcePubkey hexutil.Bytes `json:"source_pubkey"`
+	// targetPubkey: DATA, 48 Bytes
+	TargetPubkey hexutil.Bytes `json:"target_pubkey"`
+}
+
+func (cr *ConsolidationRequestV1) ToProto() (*v1.ConsolidationRequest, error) {
+	srcAddress, err := bytesutil.DecodeHexWithLength(cr.SourceAddress.String(), common.AddressLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "source_address")
+	}
+	sourcePubkey, err := bytesutil.DecodeHexWithLength(cr.SourcePubkey.String(), fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "source_pubkey")
+	}
+	targetPubkey, err := bytesutil.DecodeHexWithLength(cr.TargetPubkey.String(), fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "target_pubkey")
+	}
+	return &v1.ConsolidationRequest{
+		SourceAddress: srcAddress,
+		SourcePubkey:  sourcePubkey,
+		TargetPubkey:  targetPubkey,
+	}, nil
+}
+
 // ErrorMessage is a JSON representation of the builder API's returned error message.
 type ErrorMessage struct {
 	Code        int      `json:"code"`

api/client/builder/types_test.go

@@ -154,6 +154,64 @@ var testExampleHeaderResponseDeneb = `{
   }
 }`
 
+var testExampleHeaderResponseElectra = `{
+  "version": "electra",
+  "data": {
+    "message": {
+      "header": {
+        "parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+        "state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+        "prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "block_number": "1",
+        "gas_limit": "1",
+        "gas_used": "1",
+        "timestamp": "1",
+        "extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "base_fee_per_gas": "1",
+        "blob_gas_used": "1",
+        "excess_blob_gas": "1",
+        "block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "transactions_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "withdrawals_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"
+      },
+      "blob_kzg_commitments": [
+        "0xa94170080872584e54a1cf092d845703b13907f2e6b3b1c0ad573b910530499e3bcd48c6378846b80d2bfa58c81cf3d5"
+      ],
+      "execution_requests": {
+        "deposits": [
+          {
+            "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a",
+            "withdrawal_credentials": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+            "amount": "1",
+            "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505",
+            "index": "1"
+          }
+        ],
+        "withdrawals": [
+          {
+            "source_address": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+            "validator_pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a",
+            "amount": "1"
+          }
+        ],
+        "consolidations": [
+          {
+            "source_address": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+            "source_pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a",
+            "target_pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
+          }
+        ]
+      },
+      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
+      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
+    },
+    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+  }
+}`
+
 var testExampleHeaderResponseDenebNoBundle = `{
   "version": "deneb",
   "data": {
@@ -1924,9 +1982,9 @@ func TestEmptyResponseBody(t *testing.T) {
 		emptyResponse := &ExecutionPayloadResponse{}
 		require.NoError(t, json.Unmarshal(empty, emptyResponse))
 		_, err := emptyResponse.ParsePayload()
-		require.ErrorIs(t, err, consensusblocks.ErrUnsupportedVersion)
+		require.ErrorContains(t, "unsupported version", err)
 	})
-	versions := []int{version.Bellatrix, version.Capella, version.Deneb}
+	versions := []int{version.Bellatrix, version.Capella, version.Deneb, version.Electra}
 	for i := range versions {
 		vstr := version.String(versions[i])
 		t.Run("populated version without payload"+vstr, func(t *testing.T) {

api/client/client.go

@@ -8,13 +8,15 @@ import (
 	"net/url"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 )
 
 // Client is a wrapper object around the HTTP client.
 type Client struct {
-	hc      *http.Client
-	baseURL *url.URL
-	token   string
+	hc          *http.Client
+	baseURL     *url.URL
+	token       string
+	maxBodySize int64
 }
 
 // NewClient constructs a new client with the provided options (ex WithTimeout).
@@ -26,8 +28,9 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {
 		return nil, err
 	}
 	c := &Client{
-		hc:      &http.Client{},
-		baseURL: u,
+		hc:          &http.Client{},
+		baseURL:     u,
+		maxBodySize: httputil.MaxBodySize,
 	}
 	for _, o := range opts {
 		o(c)
@@ -59,7 +62,7 @@ func urlForHost(h string) (*url.URL, error) {
 	// try to parse as host:port
 	host, port, err := net.SplitHostPort(h)
 	if err != nil {
-		return nil, ErrMalformedHostname
+		return nil, httputil.ErrMalformedHostname
 	}
 	return &url.URL{Host: net.JoinHostPort(host, port), Scheme: "http"}, nil
 }
@@ -72,7 +75,7 @@ func (c *Client) NodeURL() string {
 // Get is a generic, opinionated GET function to reduce boilerplate amongst the getters in this package.
 func (c *Client) Get(ctx context.Context, path string, opts ...ReqOption) ([]byte, error) {
 	u := c.baseURL.ResolveReference(&url.URL{Path: path})
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), http.NoBody)
 	if err != nil {
 		return nil, err
 	}
@@ -87,9 +90,9 @@ func (c *Client) Get(ctx context.Context, path string, opts ...ReqOption) ([]byt
 		err = r.Body.Close()
 	}()
 	if r.StatusCode != http.StatusOK {
-		return nil, Non200Err(r)
+		return nil, httputil.Non200Err(r)
 	}
-	b, err := io.ReadAll(r.Body)
+	b, err := io.ReadAll(io.LimitReader(r.Body, c.maxBodySize))
 	if err != nil {
 		return nil, errors.Wrap(err, "error reading http response body")
 	}

api/client/client_test.go

@@ -4,6 +4,7 @@ import (
 	"net/url"
 	"testing"
 
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
 
@@ -18,7 +19,7 @@ func TestValidHostname(t *testing.T) {
 		{
 			name:    "hostname without port",
 			hostArg: "mydomain.org",
-			err:     ErrMalformedHostname,
+			err:     httputil.ErrMalformedHostname,
 		},
 	}
 	for _, c := range cases {

api/client/event/BUILD.bazel

@@ -9,8 +9,7 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/v5/api/client/event",
     visibility = ["//visibility:public"],
     deps = [
-        "//api:go_default_library",
-        "//api/client:go_default_library",
+        "//api/httputil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],

api/client/event/event_stream.go

@@ -8,8 +8,7 @@ import (
 	"strings"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api"
-	"github.com/prysmaticlabs/prysm/v5/api/client"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -85,13 +84,13 @@ func (h *EventStream) Subscribe(eventsChannel chan<- *Event) {
 			Data:      []byte(errors.Wrap(err, "failed to create HTTP request").Error()),
 		}
 	}
-	req.Header.Set("Accept", api.EventStreamMediaType)
-	req.Header.Set("Connection", api.KeepAlive)
+	req.Header.Set("Accept", httputil.EventStreamMediaType)
+	req.Header.Set("Connection", httputil.KeepAlive)
 	resp, err := h.httpClient.Do(req)
 	if err != nil {
 		eventsChannel <- &Event{
 			EventType: EventConnectionError,
-			Data:      []byte(errors.Wrap(err, client.ErrConnectionIssue.Error()).Error()),
+			Data:      []byte(errors.Wrap(err, httputil.ErrConnectionIssue.Error()).Error()),
 		}
 		return
 	}
@@ -145,7 +144,7 @@ func (h *EventStream) Subscribe(eventsChannel chan<- *Event) {
 	if err := scanner.Err(); err != nil {
 		eventsChannel <- &Event{
 			EventType: EventConnectionError,
-			Data:      []byte(errors.Wrap(err, errors.Wrap(client.ErrConnectionIssue, "scanner failed").Error()).Error()),
+			Data:      []byte(errors.Wrap(err, errors.Wrap(httputil.ErrConnectionIssue, "scanner failed").Error()).Error()),
 		}
 	}
 }

api/client/options.go

@@ -46,3 +46,10 @@ func WithAuthenticationToken(token string) ClientOpt {
 		c.token = token
 	}
 }
+
+// WithMaxBodySize overrides the default max body size of 8MB.
+func WithMaxBodySize(size int64) ClientOpt {
+	return func(c *Client) {
+		c.maxBodySize = size
+	}
+}

api/grpcutil/BUILD.bazel

@@ -3,10 +3,10 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
-        "grpcutils.go",
+        "common.go",
         "parameters.go",
     ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/grpc",
+    importpath = "github.com/prysmaticlabs/prysm/v5/api/grpcutil",
     visibility = ["//visibility:public"],
     deps = [
         "@com_github_sirupsen_logrus//:go_default_library",
@@ -17,7 +17,7 @@ go_library(
 
 go_test(
     name = "go_default_test",
-    srcs = ["grpcutils_test.go"],
+    srcs = ["common_test.go"],
     embed = [":go_default_library"],
     deps = [
         "//testing/assert:go_default_library",

api/grpcutil/common.go

@@ -1,4 +1,4 @@
-package grpc
+package grpcutil
 
 import (
 	"context"
@@ -74,7 +74,7 @@ func AppendHeaders(parent context.Context, headers []string) context.Context {
 				logrus.Warnf("Incorrect gRPC header flag format. Skipping %v", keyValue[0])
 				continue
 			}
-			parent = metadata.AppendToOutgoingContext(parent, keyValue[0], strings.Join(keyValue[1:], "="))
+			parent = metadata.AppendToOutgoingContext(parent, keyValue[0], strings.Join(keyValue[1:], "=")) // nolint:fatcontext
 		}
 	}
 	return parent

api/grpcutil/common_test.go

@@ -1,4 +1,4 @@
-package grpc
+package grpcutil
 
 import (
 	"context"

api/grpcutil/parameters.go

@@ -1,4 +1,4 @@
-package grpc
+package grpcutil
 
 // CustomErrorMetadataKey is the name of the metadata key storing additional error information.
 // Metadata value is expected to be a byte-encoded JSON object.

api/httputil/BUILD.bazel

@@ -3,24 +3,31 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "common.go",
+        "constants.go",
         "errors.go",
+        "headers.go",
         "reader.go",
         "writer.go",
     ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/network/httputil",
+    importpath = "github.com/prysmaticlabs/prysm/v5/api/httputil",
     visibility = ["//visibility:public"],
     deps = [
-        "//api:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["reader_test.go"],
+    srcs = [
+        "common_test.go",
+        "reader_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
-        "//api:go_default_library",
+        "//consensus-types/primitives:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
     ],

api/httputil/common.go

@@ -0,0 +1,23 @@
+package httputil
+
+import (
+	"fmt"
+	neturl "net/url"
+	"strconv"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+)
+
+// Uint64ToString is a util function that will convert uints to string
+func Uint64ToString[T uint64 | primitives.Slot | primitives.ValidatorIndex | primitives.CommitteeIndex | primitives.Epoch](val T) string {
+	return strconv.FormatUint(uint64(val), 10)
+}
+
+// BuildURL is a util function that assists with adding query parameters to the url
+func BuildURL(path string, queryParams ...neturl.Values) string {
+	if len(queryParams) == 0 {
+		return path
+	}
+
+	return fmt.Sprintf("%s?%s", path, queryParams[0].Encode())
+}

api/httputil/common_test.go

@@ -0,0 +1,37 @@
+package httputil
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+)
+
+func TestBeaconApiHelpers_TestUint64ToString(t *testing.T) {
+	const expectedResult = "1234"
+	const val = uint64(1234)
+
+	assert.Equal(t, expectedResult, Uint64ToString(val))
+	assert.Equal(t, expectedResult, Uint64ToString(primitives.Slot(val)))
+	assert.Equal(t, expectedResult, Uint64ToString(primitives.ValidatorIndex(val)))
+	assert.Equal(t, expectedResult, Uint64ToString(primitives.CommitteeIndex(val)))
+	assert.Equal(t, expectedResult, Uint64ToString(primitives.Epoch(val)))
+}
+
+func TestBuildURL_NoParams(t *testing.T) {
+	wanted := "/aaa/bbb/ccc"
+	actual := BuildURL("/aaa/bbb/ccc")
+	assert.Equal(t, wanted, actual)
+}
+
+func TestBuildURL_WithParams(t *testing.T) {
+	params := url.Values{}
+	params.Add("xxxx", "1")
+	params.Add("yyyy", "2")
+	params.Add("zzzz", "3")
+
+	wanted := "/aaa/bbb/ccc?xxxx=1&yyyy=2&zzzz=3"
+	actual := BuildURL("/aaa/bbb/ccc", params)
+	assert.Equal(t, wanted, actual)
+}

api/httputil/constants.go

@@ -1,4 +1,4 @@
-package api
+package httputil
 
 const (
 	WebUrlPrefix        = "/v2/validator/"
@@ -7,3 +7,9 @@ const (
 	SystemLogsPrefix    = "health/logs"
 	AuthTokenFileName   = "auth-token"
 )
+
+const (
+	MaxBodySize      int64 = 1 << 23 // 8MB default, WithMaxBodySize can override
+	MaxBodySizeState int64 = 1 << 29 // 512MB
+	MaxErrBodySize   int64 = 1 << 17 // 128KB
+)

api/httputil/errors.go

@@ -1,4 +1,4 @@
-package client
+package httputil
 
 import (
 	"fmt"
@@ -8,6 +8,14 @@ import (
 	"github.com/pkg/errors"
 )
 
+func HandleError(w http.ResponseWriter, message string, code int) {
+	errJson := &DefaultJsonError{
+		Message: message,
+		Code:    code,
+	}
+	WriteError(w, errJson)
+}
+
 // ErrMalformedHostname is used to indicate if a host name's format is incorrect.
 var ErrMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
 
@@ -25,16 +33,16 @@ var ErrInvalidNodeVersion = errors.New("invalid node version response")
 var ErrConnectionIssue = errors.New("could not connect")
 
 // Non200Err is a function that parses an HTTP response to handle responses that are not 200 with a formatted error.
-func Non200Err(response *http.Response) error {
-	bodyBytes, err := io.ReadAll(response.Body)
+func Non200Err(r *http.Response) error {
+	b, err := io.ReadAll(io.LimitReader(r.Body, MaxErrBodySize))
 	var body string
 	if err != nil {
 		body = "(Unable to read response body.)"
 	} else {
-		body = "response body:\n" + string(bodyBytes)
+		body = "response body:\n" + string(b)
 	}
-	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
-	switch response.StatusCode {
+	msg := fmt.Sprintf("code=%d, url=%s, body=%s", r.StatusCode, r.Request.URL, body)
+	switch r.StatusCode {
 	case http.StatusNotFound:
 		return errors.Wrap(ErrNotFound, msg)
 	default:

api/httputil/headers.go

@@ -1,4 +1,4 @@
-package api
+package httputil
 
 import "net/http"
 

api/httputil/reader.go

@@ -5,8 +5,6 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
-
-	"github.com/prysmaticlabs/prysm/v5/api"
 )
 
 // match a number with optional decimals
@@ -23,7 +21,7 @@ func RespondWithSsz(req *http.Request) bool {
 	for _, t := range types {
 		values := strings.Split(t, ";")
 		name := values[0]
-		if name != api.JsonMediaType && name != api.OctetStreamMediaType {
+		if name != JsonMediaType && name != OctetStreamMediaType {
 			continue
 		}
 		// no params specified
@@ -49,10 +47,10 @@ func RespondWithSsz(req *http.Request) bool {
 		}
 	}
 
-	return currentType == api.OctetStreamMediaType
+	return currentType == OctetStreamMediaType
 }
 
 // IsRequestSsz checks if the request object should be interpreted as ssz
 func IsRequestSsz(req *http.Request) bool {
-	return req.Header.Get("Content-Type") == api.OctetStreamMediaType
+	return req.Header.Get("Content-Type") == OctetStreamMediaType
 }

api/httputil/reader_test.go

@@ -7,7 +7,6 @@ import (
 	"net/http/httptest"
 	"testing"
 
-	"github.com/prysmaticlabs/prysm/v5/api"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
@@ -15,42 +14,42 @@ import (
 func TestRespondWithSsz(t *testing.T) {
 	t.Run("ssz_requested", func(t *testing.T) {
 		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
-		request.Header["Accept"] = []string{api.OctetStreamMediaType}
+		request.Header["Accept"] = []string{OctetStreamMediaType}
 		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})
 
 	t.Run("ssz_content_type_first", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s", api.OctetStreamMediaType, api.JsonMediaType)}
+		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s", OctetStreamMediaType, JsonMediaType)}
 		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})
 
 	t.Run("ssz_content_type_preferred_1", func(t *testing.T) {
 		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
-		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.9,%s", api.JsonMediaType, api.OctetStreamMediaType)}
+		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.9,%s", JsonMediaType, OctetStreamMediaType)}
 		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})
 
 	t.Run("ssz_content_type_preferred_2", func(t *testing.T) {
 		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
-		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.95,%s;q=0.9", api.OctetStreamMediaType, api.JsonMediaType)}
+		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.95,%s;q=0.9", OctetStreamMediaType, JsonMediaType)}
 		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})
 
 	t.Run("other_content_type_preferred", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9", api.JsonMediaType, api.OctetStreamMediaType)}
+		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9", JsonMediaType, OctetStreamMediaType)}
 		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})
 
 	t.Run("other_params", func(t *testing.T) {
 		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
-		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9,otherparam=xyz", api.JsonMediaType, api.OctetStreamMediaType)}
+		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9,otherparam=xyz", JsonMediaType, OctetStreamMediaType)}
 		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})
@@ -96,7 +95,7 @@ func TestIsRequestSsz(t *testing.T) {
 		_, err := body.WriteString("something")
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", &body)
-		request.Header["Content-Type"] = []string{api.OctetStreamMediaType}
+		request.Header["Content-Type"] = []string{OctetStreamMediaType}
 		result := IsRequestSsz(request)
 		assert.Equal(t, true, result)
 	})
@@ -116,7 +115,7 @@ func TestIsRequestSsz(t *testing.T) {
 
 	t.Run("ssz Post json content type", func(t *testing.T) {
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", nil)
-		request.Header["Content-Type"] = []string{api.JsonMediaType}
+		request.Header["Content-Type"] = []string{JsonMediaType}
 		result := IsRequestSsz(request)
 		assert.Equal(t, false, result)
 	})

api/httputil/writer.go

@@ -8,7 +8,6 @@ import (
 	"net/http"
 	"strconv"
 
-	"github.com/prysmaticlabs/prysm/v5/api"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -32,7 +31,7 @@ func (e *DefaultJsonError) Error() string {
 
 // WriteJson writes the response message in JSON format.
 func WriteJson(w http.ResponseWriter, v any) {
-	w.Header().Set("Content-Type", api.JsonMediaType)
+	w.Header().Set("Content-Type", JsonMediaType)
 	w.WriteHeader(http.StatusOK)
 	if err := json.NewEncoder(w).Encode(v); err != nil {
 		log.WithError(err).Error("Could not write response message")
@@ -40,10 +39,9 @@ func WriteJson(w http.ResponseWriter, v any) {
 }
 
 // WriteSsz writes the response message in ssz format
-func WriteSsz(w http.ResponseWriter, respSsz []byte, fileName string) {
+func WriteSsz(w http.ResponseWriter, respSsz []byte) {
 	w.Header().Set("Content-Length", strconv.Itoa(len(respSsz)))
-	w.Header().Set("Content-Type", api.OctetStreamMediaType)
-	w.Header().Set("Content-Disposition", "attachment; filename="+fileName)
+	w.Header().Set("Content-Type", OctetStreamMediaType)
 	if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(respSsz))); err != nil {
 		log.WithError(err).Error("could not write response message")
 	}
@@ -57,7 +55,7 @@ func WriteError(w http.ResponseWriter, errJson HasStatusCode) {
 		return
 	}
 	w.Header().Set("Content-Length", strconv.Itoa(len(j)))
-	w.Header().Set("Content-Type", api.JsonMediaType)
+	w.Header().Set("Content-Type", JsonMediaType)
 	w.WriteHeader(errJson.StatusCode())
 	if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(j))); err != nil {
 		log.WithError(err).Error("Could not write error message")

api/server/middleware/BUILD.bazel

@@ -19,7 +19,7 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
-        "//api:go_default_library",
+        "//api/httputil:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
     ],

api/server/middleware/middleware_test.go

@@ -5,7 +5,7 @@ import (
 	"net/http/httptest"
 	"testing"
 
-	"github.com/prysmaticlabs/prysm/v5/api"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
 
@@ -55,7 +55,7 @@ func TestNormalizeQueryValuesHandler(t *testing.T) {
 }
 
 func TestContentTypeHandler(t *testing.T) {
-	acceptedMediaTypes := []string{api.JsonMediaType, api.OctetStreamMediaType}
+	acceptedMediaTypes := []string{httputil.JsonMediaType, httputil.OctetStreamMediaType}
 
 	nextHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		_, err := w.Write([]byte("next handler"))
@@ -72,12 +72,12 @@ func TestContentTypeHandler(t *testing.T) {
 	}{
 		{
 			name:               "Accepted Content-Type - application/json",
-			contentType:        api.JsonMediaType,
+			contentType:        httputil.JsonMediaType,
 			expectedStatusCode: http.StatusOK,
 		},
 		{
 			name:               "Accepted Content-Type - ssz format",
-			contentType:        api.OctetStreamMediaType,
+			contentType:        httputil.OctetStreamMediaType,
 			expectedStatusCode: http.StatusOK,
 		},
 		{

api/server/structs/BUILD.bazel

@@ -4,9 +4,11 @@ go_library(
     name = "go_default_library",
     srcs = [
         "block.go",
+        "block_execution.go",
         "conversions.go",
         "conversions_blob.go",
         "conversions_block.go",
+        "conversions_block_execution.go",
         "conversions_lightclient.go",
         "conversions_state.go",
         "endpoints_beacon.go",
@@ -28,6 +30,7 @@ go_library(
         "//api/server:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
@@ -36,9 +39,8 @@ go_library(
         "//math:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
-        "//proto/migration:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -47,10 +49,16 @@ go_library(
 
 go_test(
     name = "go_default_test",
-    srcs = ["conversions_test.go"],
+    srcs = [
+        "conversions_block_execution_test.go",
+        "conversions_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
+        "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//testing/require:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
     ],
 )

api/server/structs/block.go

@@ -14,6 +14,10 @@ type SignedMessageJsoner interface {
 	SigString() string
 }
 
+// ----------------------------------------------------------------------------
+// Phase 0
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlock struct {
 	Message   *BeaconBlock `json:"message"`
 	Signature string       `json:"signature"`
@@ -48,6 +52,29 @@ type BeaconBlockBody struct {
 	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
 }
 
+type SignedBeaconBlockHeaderContainer struct {
+	Header    *SignedBeaconBlockHeader `json:"header"`
+	Root      string                   `json:"root"`
+	Canonical bool                     `json:"canonical"`
+}
+
+type SignedBeaconBlockHeader struct {
+	Message   *BeaconBlockHeader `json:"message"`
+	Signature string             `json:"signature"`
+}
+
+type BeaconBlockHeader struct {
+	Slot          string `json:"slot"`
+	ProposerIndex string `json:"proposer_index"`
+	ParentRoot    string `json:"parent_root"`
+	StateRoot     string `json:"state_root"`
+	BodyRoot      string `json:"body_root"`
+}
+
+// ----------------------------------------------------------------------------
+// Altair
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockAltair struct {
 	Message   *BeaconBlockAltair `json:"message"`
 	Signature string             `json:"signature"`
@@ -83,6 +110,10 @@ type BeaconBlockBodyAltair struct {
 	SyncAggregate     *SyncAggregate         `json:"sync_aggregate"`
 }
 
+// ----------------------------------------------------------------------------
+// Bellatrix
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockBellatrix struct {
 	Message   *BeaconBlockBellatrix `json:"message"`
 	Signature string                `json:"signature"`
@@ -155,6 +186,10 @@ type BlindedBeaconBlockBodyBellatrix struct {
 	ExecutionPayloadHeader *ExecutionPayloadHeader `json:"execution_payload_header"`
 }
 
+// ----------------------------------------------------------------------------
+// Capella
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockCapella struct {
 	Message   *BeaconBlockCapella `json:"message"`
 	Signature string              `json:"signature"`
@@ -229,6 +264,10 @@ type BlindedBeaconBlockBodyCapella struct {
 	BLSToExecutionChanges  []*SignedBLSToExecutionChange  `json:"bls_to_execution_changes"`
 }
 
+// ----------------------------------------------------------------------------
+// Deneb
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockContentsDeneb struct {
 	SignedBlock *SignedBeaconBlockDeneb `json:"signed_block"`
 	KzgProofs   []string                `json:"kzg_proofs"`
@@ -317,6 +356,10 @@ type BlindedBeaconBlockBodyDeneb struct {
 	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
 }
 
+// ----------------------------------------------------------------------------
+// Electra
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockContentsElectra struct {
 	SignedBlock *SignedBeaconBlockElectra `json:"signed_block"`
 	KzgProofs   []string                  `json:"kzg_proofs"`
@@ -362,7 +405,7 @@ type BeaconBlockBodyElectra struct {
 	Deposits              []*Deposit                    `json:"deposits"`
 	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
 	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
-	ExecutionPayload      *ExecutionPayloadElectra      `json:"execution_payload"`
+	ExecutionPayload      *ExecutionPayloadDeneb        `json:"execution_payload"`
 	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
 	BlobKzgCommitments    []string                      `json:"blob_kzg_commitments"`
 	ExecutionRequests     *ExecutionRequests            `json:"execution_requests"`
@@ -392,156 +435,71 @@ func (s *SignedBlindedBeaconBlockElectra) SigString() string {
 }
 
 type BlindedBeaconBlockBodyElectra struct {
-	RandaoReveal           string                         `json:"randao_reveal"`
-	Eth1Data               *Eth1Data                      `json:"eth1_data"`
-	Graffiti               string                         `json:"graffiti"`
-	ProposerSlashings      []*ProposerSlashing            `json:"proposer_slashings"`
-	AttesterSlashings      []*AttesterSlashingElectra     `json:"attester_slashings"`
-	Attestations           []*AttestationElectra          `json:"attestations"`
-	Deposits               []*Deposit                     `json:"deposits"`
-	VoluntaryExits         []*SignedVoluntaryExit         `json:"voluntary_exits"`
-	SyncAggregate          *SyncAggregate                 `json:"sync_aggregate"`
-	ExecutionPayloadHeader *ExecutionPayloadHeaderElectra `json:"execution_payload_header"`
-	BLSToExecutionChanges  []*SignedBLSToExecutionChange  `json:"bls_to_execution_changes"`
-	BlobKzgCommitments     []string                       `json:"blob_kzg_commitments"`
-	ExecutionRequests      *ExecutionRequests             `json:"execution_requests"`
+	RandaoReveal           string                        `json:"randao_reveal"`
+	Eth1Data               *Eth1Data                     `json:"eth1_data"`
+	Graffiti               string                        `json:"graffiti"`
+	ProposerSlashings      []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings      []*AttesterSlashingElectra    `json:"attester_slashings"`
+	Attestations           []*AttestationElectra         `json:"attestations"`
+	Deposits               []*Deposit                    `json:"deposits"`
+	VoluntaryExits         []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate          *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayloadHeader *ExecutionPayloadHeaderDeneb  `json:"execution_payload_header"`
+	BLSToExecutionChanges  []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
+	ExecutionRequests      *ExecutionRequests            `json:"execution_requests"`
 }
 
-type SignedBeaconBlockHeaderContainer struct {
-	Header    *SignedBeaconBlockHeader `json:"header"`
-	Root      string                   `json:"root"`
-	Canonical bool                     `json:"canonical"`
+// ----------------------------------------------------------------------------
+// Fulu
+// ----------------------------------------------------------------------------
+
+type SignedBeaconBlockContentsFulu struct {
+	SignedBlock *SignedBeaconBlockFulu `json:"signed_block"`
+	KzgProofs   []string               `json:"kzg_proofs"`
+	Blobs       []string               `json:"blobs"`
 }
 
-type SignedBeaconBlockHeader struct {
-	Message   *BeaconBlockHeader `json:"message"`
-	Signature string             `json:"signature"`
+type BeaconBlockContentsFulu struct {
+	Block     *BeaconBlockElectra `json:"block"`
+	KzgProofs []string            `json:"kzg_proofs"`
+	Blobs     []string            `json:"blobs"`
 }
 
-type BeaconBlockHeader struct {
-	Slot          string `json:"slot"`
-	ProposerIndex string `json:"proposer_index"`
-	ParentRoot    string `json:"parent_root"`
-	StateRoot     string `json:"state_root"`
-	BodyRoot      string `json:"body_root"`
+type SignedBeaconBlockFulu struct {
+	Message   *BeaconBlockElectra `json:"message"`
+	Signature string              `json:"signature"`
 }
 
-type ExecutionPayload struct {
-	ParentHash    string   `json:"parent_hash"`
-	FeeRecipient  string   `json:"fee_recipient"`
-	StateRoot     string   `json:"state_root"`
-	ReceiptsRoot  string   `json:"receipts_root"`
-	LogsBloom     string   `json:"logs_bloom"`
-	PrevRandao    string   `json:"prev_randao"`
-	BlockNumber   string   `json:"block_number"`
-	GasLimit      string   `json:"gas_limit"`
-	GasUsed       string   `json:"gas_used"`
-	Timestamp     string   `json:"timestamp"`
-	ExtraData     string   `json:"extra_data"`
-	BaseFeePerGas string   `json:"base_fee_per_gas"`
-	BlockHash     string   `json:"block_hash"`
-	Transactions  []string `json:"transactions"`
+var _ SignedMessageJsoner = &SignedBeaconBlockFulu{}
+
+func (s *SignedBeaconBlockFulu) MessageRawJson() ([]byte, error) {
+	return json.Marshal(s.Message)
 }
 
-type ExecutionPayloadHeader struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
+func (s *SignedBeaconBlockFulu) SigString() string {
+	return s.Signature
 }
 
-type ExecutionPayloadCapella struct {
-	ParentHash    string        `json:"parent_hash"`
-	FeeRecipient  string        `json:"fee_recipient"`
-	StateRoot     string        `json:"state_root"`
-	ReceiptsRoot  string        `json:"receipts_root"`
-	LogsBloom     string        `json:"logs_bloom"`
-	PrevRandao    string        `json:"prev_randao"`
-	BlockNumber   string        `json:"block_number"`
-	GasLimit      string        `json:"gas_limit"`
-	GasUsed       string        `json:"gas_used"`
-	Timestamp     string        `json:"timestamp"`
-	ExtraData     string        `json:"extra_data"`
-	BaseFeePerGas string        `json:"base_fee_per_gas"`
-	BlockHash     string        `json:"block_hash"`
-	Transactions  []string      `json:"transactions"`
-	Withdrawals   []*Withdrawal `json:"withdrawals"`
+type BlindedBeaconBlockFulu struct {
+	Slot          string                         `json:"slot"`
+	ProposerIndex string                         `json:"proposer_index"`
+	ParentRoot    string                         `json:"parent_root"`
+	StateRoot     string                         `json:"state_root"`
+	Body          *BlindedBeaconBlockBodyElectra `json:"body"`
 }
 
-type ExecutionPayloadHeaderCapella struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-	WithdrawalsRoot  string `json:"withdrawals_root"`
+type SignedBlindedBeaconBlockFulu struct {
+	Message   *BlindedBeaconBlockFulu `json:"message"`
+	Signature string                  `json:"signature"`
 }
 
-type ExecutionPayloadDeneb struct {
-	ParentHash    string        `json:"parent_hash"`
-	FeeRecipient  string        `json:"fee_recipient"`
-	StateRoot     string        `json:"state_root"`
-	ReceiptsRoot  string        `json:"receipts_root"`
-	LogsBloom     string        `json:"logs_bloom"`
-	PrevRandao    string        `json:"prev_randao"`
-	BlockNumber   string        `json:"block_number"`
-	GasLimit      string        `json:"gas_limit"`
-	GasUsed       string        `json:"gas_used"`
-	Timestamp     string        `json:"timestamp"`
-	ExtraData     string        `json:"extra_data"`
-	BaseFeePerGas string        `json:"base_fee_per_gas"`
-	BlockHash     string        `json:"block_hash"`
-	Transactions  []string      `json:"transactions"`
-	Withdrawals   []*Withdrawal `json:"withdrawals"`
-	BlobGasUsed   string        `json:"blob_gas_used"`
-	ExcessBlobGas string        `json:"excess_blob_gas"`
+var _ SignedMessageJsoner = &SignedBlindedBeaconBlockFulu{}
+
+func (s *SignedBlindedBeaconBlockFulu) MessageRawJson() ([]byte, error) {
+	return json.Marshal(s.Message)
 }
 
-type ExecutionPayloadElectra = ExecutionPayloadDeneb
-
-type ExecutionPayloadHeaderDeneb struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-	WithdrawalsRoot  string `json:"withdrawals_root"`
-	BlobGasUsed      string `json:"blob_gas_used"`
-	ExcessBlobGas    string `json:"excess_blob_gas"`
-}
-
-type ExecutionPayloadHeaderElectra = ExecutionPayloadHeaderDeneb
-
-type ExecutionRequests struct {
-	Deposits       []*DepositRequest       `json:"deposits"`
-	Withdrawals    []*WithdrawalRequest    `json:"withdrawals"`
-	Consolidations []*ConsolidationRequest `json:"consolidations"`
+func (s *SignedBlindedBeaconBlockFulu) SigString() string {
+	return s.Signature
 }

api/server/structs/block_execution.go

@@ -0,0 +1,157 @@
+package structs
+
+// ----------------------------------------------------------------------------
+// Bellatrix
+// ----------------------------------------------------------------------------
+
+type ExecutionPayload struct {
+	ParentHash    string   `json:"parent_hash"`
+	FeeRecipient  string   `json:"fee_recipient"`
+	StateRoot     string   `json:"state_root"`
+	ReceiptsRoot  string   `json:"receipts_root"`
+	LogsBloom     string   `json:"logs_bloom"`
+	PrevRandao    string   `json:"prev_randao"`
+	BlockNumber   string   `json:"block_number"`
+	GasLimit      string   `json:"gas_limit"`
+	GasUsed       string   `json:"gas_used"`
+	Timestamp     string   `json:"timestamp"`
+	ExtraData     string   `json:"extra_data"`
+	BaseFeePerGas string   `json:"base_fee_per_gas"`
+	BlockHash     string   `json:"block_hash"`
+	Transactions  []string `json:"transactions"`
+}
+
+type ExecutionPayloadHeader struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+}
+
+// ----------------------------------------------------------------------------
+// Capella
+// ----------------------------------------------------------------------------
+
+type ExecutionPayloadCapella struct {
+	ParentHash    string        `json:"parent_hash"`
+	FeeRecipient  string        `json:"fee_recipient"`
+	StateRoot     string        `json:"state_root"`
+	ReceiptsRoot  string        `json:"receipts_root"`
+	LogsBloom     string        `json:"logs_bloom"`
+	PrevRandao    string        `json:"prev_randao"`
+	BlockNumber   string        `json:"block_number"`
+	GasLimit      string        `json:"gas_limit"`
+	GasUsed       string        `json:"gas_used"`
+	Timestamp     string        `json:"timestamp"`
+	ExtraData     string        `json:"extra_data"`
+	BaseFeePerGas string        `json:"base_fee_per_gas"`
+	BlockHash     string        `json:"block_hash"`
+	Transactions  []string      `json:"transactions"`
+	Withdrawals   []*Withdrawal `json:"withdrawals"`
+}
+
+type ExecutionPayloadHeaderCapella struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+	WithdrawalsRoot  string `json:"withdrawals_root"`
+}
+
+// ----------------------------------------------------------------------------
+// Deneb
+// ----------------------------------------------------------------------------
+
+type ExecutionPayloadDeneb struct {
+	ParentHash    string        `json:"parent_hash"`
+	FeeRecipient  string        `json:"fee_recipient"`
+	StateRoot     string        `json:"state_root"`
+	ReceiptsRoot  string        `json:"receipts_root"`
+	LogsBloom     string        `json:"logs_bloom"`
+	PrevRandao    string        `json:"prev_randao"`
+	BlockNumber   string        `json:"block_number"`
+	GasLimit      string        `json:"gas_limit"`
+	GasUsed       string        `json:"gas_used"`
+	Timestamp     string        `json:"timestamp"`
+	ExtraData     string        `json:"extra_data"`
+	BaseFeePerGas string        `json:"base_fee_per_gas"`
+	BlockHash     string        `json:"block_hash"`
+	Transactions  []string      `json:"transactions"`
+	Withdrawals   []*Withdrawal `json:"withdrawals"`
+	BlobGasUsed   string        `json:"blob_gas_used"`
+	ExcessBlobGas string        `json:"excess_blob_gas"`
+}
+
+type ExecutionPayloadHeaderDeneb struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+	WithdrawalsRoot  string `json:"withdrawals_root"`
+	BlobGasUsed      string `json:"blob_gas_used"`
+	ExcessBlobGas    string `json:"excess_blob_gas"`
+}
+
+// ----------------------------------------------------------------------------
+// Electra
+// ----------------------------------------------------------------------------
+
+type ExecutionRequests struct {
+	Deposits       []*DepositRequest       `json:"deposits"`
+	Withdrawals    []*WithdrawalRequest    `json:"withdrawals"`
+	Consolidations []*ConsolidationRequest `json:"consolidations"`
+}
+
+type DepositRequest struct {
+	Pubkey                string `json:"pubkey"`
+	WithdrawalCredentials string `json:"withdrawal_credentials"`
+	Amount                string `json:"amount"`
+	Signature             string `json:"signature"`
+	Index                 string `json:"index"`
+}
+
+type WithdrawalRequest struct {
+	SourceAddress   string `json:"source_address"`
+	ValidatorPubkey string `json:"validator_pubkey"`
+	Amount          string `json:"amount"`
+}
+
+type ConsolidationRequest struct {
+	SourceAddress string `json:"source_address"`
+	SourcePubkey  string `json:"source_pubkey"`
+	TargetPubkey  string `json:"target_pubkey"`
+}
+
+// ----------------------------------------------------------------------------
+// Fulu
+// ----------------------------------------------------------------------------

api/server/structs/conversions.go

@@ -9,6 +9,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/api/server"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/validator"
 	"github.com/prysmaticlabs/prysm/v5/container/slice"
@@ -51,6 +52,9 @@ func HistoricalSummaryFromConsensus(s *eth.HistoricalSummary) *HistoricalSummary
 }
 
 func (s *SignedBLSToExecutionChange) ToConsensus() (*eth.SignedBLSToExecutionChange, error) {
+	if s.Message == nil {
+		return nil, server.NewDecodeError(errNilValue, "Message")
+	}
 	change, err := s.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -102,14 +106,17 @@ func SignedBLSChangeFromConsensus(ch *eth.SignedBLSToExecutionChange) *SignedBLS
 
 func SignedBLSChangesToConsensus(src []*SignedBLSToExecutionChange) ([]*eth.SignedBLSToExecutionChange, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "SignedBLSToExecutionChanges")
 	}
 	err := slice.VerifyMaxLength(src, 16)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "SignedBLSToExecutionChanges")
 	}
 	changes := make([]*eth.SignedBLSToExecutionChange, len(src))
 	for i, ch := range src {
+		if ch == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d]", i))
+		}
 		changes[i], err = ch.ToConsensus()
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d]", i))
@@ -155,6 +162,9 @@ func ForkFromConsensus(f *eth.Fork) *Fork {
 }
 
 func (s *SignedValidatorRegistration) ToConsensus() (*eth.SignedValidatorRegistrationV1, error) {
+	if s.Message == nil {
+		return nil, server.NewDecodeError(errNilValue, "Message")
+	}
 	msg, err := s.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -211,6 +221,9 @@ func SignedValidatorRegistrationFromConsensus(vr *eth.SignedValidatorRegistratio
 }
 
 func (s *SignedContributionAndProof) ToConsensus() (*eth.SignedContributionAndProof, error) {
+	if s.Message == nil {
+		return nil, server.NewDecodeError(errNilValue, "Message")
+	}
 	msg, err := s.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -235,6 +248,9 @@ func SignedContributionAndProofFromConsensus(c *eth.SignedContributionAndProof)
 }
 
 func (c *ContributionAndProof) ToConsensus() (*eth.ContributionAndProof, error) {
+	if c.Contribution == nil {
+		return nil, server.NewDecodeError(errNilValue, "Contribution")
+	}
 	contribution, err := c.Contribution.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Contribution")
@@ -243,7 +259,7 @@ func (c *ContributionAndProof) ToConsensus() (*eth.ContributionAndProof, error)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "AggregatorIndex")
 	}
-	selectionProof, err := bytesutil.DecodeHexWithLength(c.SelectionProof, 96)
+	selectionProof, err := bytesutil.DecodeHexWithLength(c.SelectionProof, fieldparams.BLSSignatureLength)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "SelectionProof")
 	}
@@ -306,6 +322,9 @@ func SyncCommitteeContributionFromConsensus(c *eth.SyncCommitteeContribution) *S
 }
 
 func (s *SignedAggregateAttestationAndProof) ToConsensus() (*eth.SignedAggregateAttestationAndProof, error) {
+	if s.Message == nil {
+		return nil, server.NewDecodeError(errNilValue, "Message")
+	}
 	msg, err := s.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -326,11 +345,14 @@ func (a *AggregateAttestationAndProof) ToConsensus() (*eth.AggregateAttestationA
 	if err != nil {
 		return nil, server.NewDecodeError(err, "AggregatorIndex")
 	}
+	if a.Aggregate == nil {
+		return nil, server.NewDecodeError(errNilValue, "Aggregate")
+	}
 	agg, err := a.Aggregate.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Aggregate")
 	}
-	proof, err := bytesutil.DecodeHexWithLength(a.SelectionProof, 96)
+	proof, err := bytesutil.DecodeHexWithLength(a.SelectionProof, fieldparams.BLSSignatureLength)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "SelectionProof")
 	}
@@ -342,6 +364,9 @@ func (a *AggregateAttestationAndProof) ToConsensus() (*eth.AggregateAttestationA
 }
 
 func (s *SignedAggregateAttestationAndProofElectra) ToConsensus() (*eth.SignedAggregateAttestationAndProofElectra, error) {
+	if s.Message == nil {
+		return nil, server.NewDecodeError(errNilValue, "Message")
+	}
 	msg, err := s.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -362,11 +387,14 @@ func (a *AggregateAttestationAndProofElectra) ToConsensus() (*eth.AggregateAttes
 	if err != nil {
 		return nil, server.NewDecodeError(err, "AggregatorIndex")
 	}
+	if a.Aggregate == nil {
+		return nil, server.NewDecodeError(errNilValue, "Aggregate")
+	}
 	agg, err := a.Aggregate.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Aggregate")
 	}
-	proof, err := bytesutil.DecodeHexWithLength(a.SelectionProof, 96)
+	proof, err := bytesutil.DecodeHexWithLength(a.SelectionProof, fieldparams.BLSSignatureLength)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "SelectionProof")
 	}
@@ -382,6 +410,9 @@ func (a *Attestation) ToConsensus() (*eth.Attestation, error) {
 	if err != nil {
 		return nil, server.NewDecodeError(err, "AggregationBits")
 	}
+	if a.Data == nil {
+		return nil, server.NewDecodeError(errNilValue, "Data")
+	}
 	data, err := a.Data.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Data")
@@ -411,6 +442,9 @@ func (a *AttestationElectra) ToConsensus() (*eth.AttestationElectra, error) {
 	if err != nil {
 		return nil, server.NewDecodeError(err, "AggregationBits")
 	}
+	if a.Data == nil {
+		return nil, server.NewDecodeError(errNilValue, "Data")
+	}
 	data, err := a.Data.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Data")
@@ -432,6 +466,44 @@ func (a *AttestationElectra) ToConsensus() (*eth.AttestationElectra, error) {
 	}, nil
 }
 
+func SingleAttFromConsensus(a *eth.SingleAttestation) *SingleAttestation {
+	return &SingleAttestation{
+		CommitteeIndex: fmt.Sprintf("%d", a.CommitteeId),
+		AttesterIndex:  fmt.Sprintf("%d", a.AttesterIndex),
+		Data:           AttDataFromConsensus(a.Data),
+		Signature:      hexutil.Encode(a.Signature),
+	}
+}
+
+func (a *SingleAttestation) ToConsensus() (*eth.SingleAttestation, error) {
+	ci, err := strconv.ParseUint(a.CommitteeIndex, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "CommitteeIndex")
+	}
+	ai, err := strconv.ParseUint(a.AttesterIndex, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "AttesterIndex")
+	}
+	if a.Data == nil {
+		return nil, server.NewDecodeError(errNilValue, "Data")
+	}
+	data, err := a.Data.ToConsensus()
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Data")
+	}
+	sig, err := bytesutil.DecodeHexWithLength(a.Signature, fieldparams.BLSSignatureLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
+
+	return &eth.SingleAttestation{
+		CommitteeId:   primitives.CommitteeIndex(ci),
+		AttesterIndex: primitives.ValidatorIndex(ai),
+		Data:          data,
+		Signature:     sig,
+	}, nil
+}
+
 func AttElectraFromConsensus(a *eth.AttestationElectra) *AttestationElectra {
 	return &AttestationElectra{
 		AggregationBits: hexutil.Encode(a.AggregationBits),
@@ -454,10 +526,16 @@ func (a *AttestationData) ToConsensus() (*eth.AttestationData, error) {
 	if err != nil {
 		return nil, server.NewDecodeError(err, "BeaconBlockRoot")
 	}
+	if a.Source == nil {
+		return nil, server.NewDecodeError(errNilValue, "Source")
+	}
 	source, err := a.Source.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Source")
 	}
+	if a.Target == nil {
+		return nil, server.NewDecodeError(errNilValue, "Target")
+	}
 	target, err := a.Target.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Target")
@@ -557,15 +635,17 @@ func (b *BeaconCommitteeSubscription) ToConsensus() (*validator.BeaconCommitteeS
 }
 
 func (e *SignedVoluntaryExit) ToConsensus() (*eth.SignedVoluntaryExit, error) {
-	sig, err := bytesutil.DecodeHexWithLength(e.Signature, fieldparams.BLSSignatureLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Signature")
+	if e.Message == nil {
+		return nil, server.NewDecodeError(errNilValue, "Message")
 	}
 	exit, err := e.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
 	}
-
+	sig, err := bytesutil.DecodeHexWithLength(e.Signature, fieldparams.BLSSignatureLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
 	return &eth.SignedVoluntaryExit{
 		Exit:      exit,
 		Signature: sig,
@@ -668,10 +748,16 @@ func Eth1DataFromConsensus(e1d *eth.Eth1Data) *Eth1Data {
 }
 
 func (s *ProposerSlashing) ToConsensus() (*eth.ProposerSlashing, error) {
+	if s.SignedHeader1 == nil {
+		return nil, server.NewDecodeError(errNilValue, "SignedHeader1")
+	}
 	h1, err := s.SignedHeader1.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "SignedHeader1")
 	}
+	if s.SignedHeader2 == nil {
+		return nil, server.NewDecodeError(errNilValue, "SignedHeader2")
+	}
 	h2, err := s.SignedHeader2.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "SignedHeader2")
@@ -684,10 +770,16 @@ func (s *ProposerSlashing) ToConsensus() (*eth.ProposerSlashing, error) {
 }
 
 func (s *AttesterSlashing) ToConsensus() (*eth.AttesterSlashing, error) {
+	if s.Attestation1 == nil {
+		return nil, server.NewDecodeError(errNilValue, "Attestation1")
+	}
 	att1, err := s.Attestation1.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Attestation1")
 	}
+	if s.Attestation2 == nil {
+		return nil, server.NewDecodeError(errNilValue, "Attestation2")
+	}
 	att2, err := s.Attestation2.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Attestation2")
@@ -696,10 +788,16 @@ func (s *AttesterSlashing) ToConsensus() (*eth.AttesterSlashing, error) {
 }
 
 func (s *AttesterSlashingElectra) ToConsensus() (*eth.AttesterSlashingElectra, error) {
+	if s.Attestation1 == nil {
+		return nil, server.NewDecodeError(errNilValue, "Attestation1")
+	}
 	att1, err := s.Attestation1.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Attestation1")
 	}
+	if s.Attestation2 == nil {
+		return nil, server.NewDecodeError(errNilValue, "Attestation2")
+	}
 	att2, err := s.Attestation2.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Attestation2")
@@ -708,6 +806,10 @@ func (s *AttesterSlashingElectra) ToConsensus() (*eth.AttesterSlashingElectra, e
 }
 
 func (a *IndexedAttestation) ToConsensus() (*eth.IndexedAttestation, error) {
+	if err := slice.VerifyMaxLength(a.AttestingIndices, params.BeaconConfig().MaxValidatorsPerCommittee); err != nil {
+		return nil, err
+	}
+
 	indices := make([]uint64, len(a.AttestingIndices))
 	var err error
 	for i, ix := range a.AttestingIndices {
@@ -716,6 +818,9 @@ func (a *IndexedAttestation) ToConsensus() (*eth.IndexedAttestation, error) {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("AttestingIndices[%d]", i))
 		}
 	}
+	if a.Data == nil {
+		return nil, server.NewDecodeError(errNilValue, "Data")
+	}
 	data, err := a.Data.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Data")
@@ -733,6 +838,13 @@ func (a *IndexedAttestation) ToConsensus() (*eth.IndexedAttestation, error) {
 }
 
 func (a *IndexedAttestationElectra) ToConsensus() (*eth.IndexedAttestationElectra, error) {
+	if err := slice.VerifyMaxLength(
+		a.AttestingIndices,
+		params.BeaconConfig().MaxValidatorsPerCommittee*params.BeaconConfig().MaxCommitteesPerSlot,
+	); err != nil {
+		return nil, err
+	}
+
 	indices := make([]uint64, len(a.AttestingIndices))
 	var err error
 	for i, ix := range a.AttestingIndices {
@@ -741,6 +853,9 @@ func (a *IndexedAttestationElectra) ToConsensus() (*eth.IndexedAttestationElectr
 			return nil, server.NewDecodeError(err, fmt.Sprintf("AttestingIndices[%d]", i))
 		}
 	}
+	if a.Data == nil {
+		return nil, server.NewDecodeError(errNilValue, "Data")
+	}
 	data, err := a.Data.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Data")
@@ -774,133 +889,13 @@ func WithdrawalFromConsensus(w *enginev1.Withdrawal) *Withdrawal {
 	}
 }
 
-func WithdrawalRequestsFromConsensus(ws []*enginev1.WithdrawalRequest) []*WithdrawalRequest {
-	result := make([]*WithdrawalRequest, len(ws))
-	for i, w := range ws {
-		result[i] = WithdrawalRequestFromConsensus(w)
-	}
-	return result
-}
-
-func WithdrawalRequestFromConsensus(w *enginev1.WithdrawalRequest) *WithdrawalRequest {
-	return &WithdrawalRequest{
-		SourceAddress:   hexutil.Encode(w.SourceAddress),
-		ValidatorPubkey: hexutil.Encode(w.ValidatorPubkey),
-		Amount:          fmt.Sprintf("%d", w.Amount),
-	}
-}
-
-func (w *WithdrawalRequest) ToConsensus() (*enginev1.WithdrawalRequest, error) {
-	src, err := bytesutil.DecodeHexWithLength(w.SourceAddress, common.AddressLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "SourceAddress")
-	}
-	pubkey, err := bytesutil.DecodeHexWithLength(w.ValidatorPubkey, fieldparams.BLSPubkeyLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "ValidatorPubkey")
-	}
-	amount, err := strconv.ParseUint(w.Amount, 10, 64)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Amount")
-	}
-	return &enginev1.WithdrawalRequest{
-		SourceAddress:   src,
-		ValidatorPubkey: pubkey,
-		Amount:          amount,
-	}, nil
-}
-
-func ConsolidationRequestsFromConsensus(cs []*enginev1.ConsolidationRequest) []*ConsolidationRequest {
-	result := make([]*ConsolidationRequest, len(cs))
-	for i, c := range cs {
-		result[i] = ConsolidationRequestFromConsensus(c)
-	}
-	return result
-}
-
-func ConsolidationRequestFromConsensus(c *enginev1.ConsolidationRequest) *ConsolidationRequest {
-	return &ConsolidationRequest{
-		SourceAddress: hexutil.Encode(c.SourceAddress),
-		SourcePubkey:  hexutil.Encode(c.SourcePubkey),
-		TargetPubkey:  hexutil.Encode(c.TargetPubkey),
-	}
-}
-
-func (c *ConsolidationRequest) ToConsensus() (*enginev1.ConsolidationRequest, error) {
-	srcAddress, err := bytesutil.DecodeHexWithLength(c.SourceAddress, common.AddressLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "SourceAddress")
-	}
-	srcPubkey, err := bytesutil.DecodeHexWithLength(c.SourcePubkey, fieldparams.BLSPubkeyLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "SourcePubkey")
-	}
-	targetPubkey, err := bytesutil.DecodeHexWithLength(c.TargetPubkey, fieldparams.BLSPubkeyLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "TargetPubkey")
-	}
-	return &enginev1.ConsolidationRequest{
-		SourceAddress: srcAddress,
-		SourcePubkey:  srcPubkey,
-		TargetPubkey:  targetPubkey,
-	}, nil
-}
-
-func DepositRequestsFromConsensus(ds []*enginev1.DepositRequest) []*DepositRequest {
-	result := make([]*DepositRequest, len(ds))
-	for i, d := range ds {
-		result[i] = DepositRequestFromConsensus(d)
-	}
-	return result
-}
-
-func DepositRequestFromConsensus(d *enginev1.DepositRequest) *DepositRequest {
-	return &DepositRequest{
-		Pubkey:                hexutil.Encode(d.Pubkey),
-		WithdrawalCredentials: hexutil.Encode(d.WithdrawalCredentials),
-		Amount:                fmt.Sprintf("%d", d.Amount),
-		Signature:             hexutil.Encode(d.Signature),
-		Index:                 fmt.Sprintf("%d", d.Index),
-	}
-}
-
-func (d *DepositRequest) ToConsensus() (*enginev1.DepositRequest, error) {
-	pubkey, err := bytesutil.DecodeHexWithLength(d.Pubkey, fieldparams.BLSPubkeyLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Pubkey")
-	}
-	withdrawalCredentials, err := bytesutil.DecodeHexWithLength(d.WithdrawalCredentials, fieldparams.RootLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "WithdrawalCredentials")
-	}
-	amount, err := strconv.ParseUint(d.Amount, 10, 64)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Amount")
-	}
-	sig, err := bytesutil.DecodeHexWithLength(d.Signature, fieldparams.BLSSignatureLength)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Signature")
-	}
-	index, err := strconv.ParseUint(d.Index, 10, 64)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Index")
-	}
-	return &enginev1.DepositRequest{
-		Pubkey:                pubkey,
-		WithdrawalCredentials: withdrawalCredentials,
-		Amount:                amount,
-		Signature:             sig,
-		Index:                 index,
-	}, nil
-}
-
 func ProposerSlashingsToConsensus(src []*ProposerSlashing) ([]*eth.ProposerSlashing, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "ProposerSlashings")
 	}
 	err := slice.VerifyMaxLength(src, 16)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "ProposerSlashings")
 	}
 	proposerSlashings := make([]*eth.ProposerSlashing, len(src))
 	for i, s := range src {
@@ -1029,11 +1024,11 @@ func ProposerSlashingFromConsensus(src *eth.ProposerSlashing) *ProposerSlashing
 
 func AttesterSlashingsToConsensus(src []*AttesterSlashing) ([]*eth.AttesterSlashing, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "AttesterSlashings")
 	}
 	err := slice.VerifyMaxLength(src, 2)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "AttesterSlashings")
 	}
 
 	attesterSlashings := make([]*eth.AttesterSlashing, len(src))
@@ -1044,10 +1039,19 @@ func AttesterSlashingsToConsensus(src []*AttesterSlashing) ([]*eth.AttesterSlash
 		if s.Attestation1 == nil {
 			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation1", i))
 		}
+
+		if s.Attestation1.Data == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation1.Data", i))
+		}
+
 		if s.Attestation2 == nil {
 			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation2", i))
 		}
 
+		if s.Attestation2.Data == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation2.Data", i))
+		}
+
 		a1Sig, err := bytesutil.DecodeHexWithLength(s.Attestation1.Signature, fieldparams.BLSSignatureLength)
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d].Attestation1.Signature", i))
@@ -1064,6 +1068,7 @@ func AttesterSlashingsToConsensus(src []*AttesterSlashing) ([]*eth.AttesterSlash
 			}
 			a1AttestingIndices[j] = attestingIndex
 		}
+
 		a1Data, err := s.Attestation1.Data.ToConsensus()
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d].Attestation1.Data", i))
@@ -1161,11 +1166,11 @@ func AttesterSlashingFromConsensus(src *eth.AttesterSlashing) *AttesterSlashing
 
 func AttesterSlashingsElectraToConsensus(src []*AttesterSlashingElectra) ([]*eth.AttesterSlashingElectra, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "AttesterSlashingsElectra")
 	}
-	err := slice.VerifyMaxLength(src, 2)
+	err := slice.VerifyMaxLength(src, fieldparams.MaxAttesterSlashingsElectra)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "AttesterSlashingsElectra")
 	}
 
 	attesterSlashings := make([]*eth.AttesterSlashingElectra, len(src))
@@ -1173,18 +1178,28 @@ func AttesterSlashingsElectraToConsensus(src []*AttesterSlashingElectra) ([]*eth
 		if s == nil {
 			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d]", i))
 		}
+
 		if s.Attestation1 == nil {
 			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation1", i))
 		}
+
+		if s.Attestation1.Data == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation1.Data", i))
+		}
+
 		if s.Attestation2 == nil {
 			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation2", i))
 		}
 
+		if s.Attestation2.Data == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d].Attestation2.Data", i))
+		}
+
 		a1Sig, err := bytesutil.DecodeHexWithLength(s.Attestation1.Signature, fieldparams.BLSSignatureLength)
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d].Attestation1.Signature", i))
 		}
-		err = slice.VerifyMaxLength(s.Attestation1.AttestingIndices, 2048)
+		err = slice.VerifyMaxLength(s.Attestation1.AttestingIndices, params.BeaconConfig().MaxValidatorsPerCommittee*params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d].Attestation1.AttestingIndices", i))
 		}
@@ -1204,7 +1219,7 @@ func AttesterSlashingsElectraToConsensus(src []*AttesterSlashingElectra) ([]*eth
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d].Attestation2.Signature", i))
 		}
-		err = slice.VerifyMaxLength(s.Attestation2.AttestingIndices, 2048)
+		err = slice.VerifyMaxLength(s.Attestation2.AttestingIndices, params.BeaconConfig().MaxValidatorsPerCommittee*params.BeaconConfig().MaxCommitteesPerSlot)
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d].Attestation2.AttestingIndices", i))
 		}
@@ -1293,15 +1308,18 @@ func AttesterSlashingElectraFromConsensus(src *eth.AttesterSlashingElectra) *Att
 
 func AttsToConsensus(src []*Attestation) ([]*eth.Attestation, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "Attestations")
 	}
 	err := slice.VerifyMaxLength(src, 128)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "Attestations")
 	}
 
 	atts := make([]*eth.Attestation, len(src))
 	for i, a := range src {
+		if a == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d]", i))
+		}
 		atts[i], err = a.ToConsensus()
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d]", i))
@@ -1320,15 +1338,18 @@ func AttsFromConsensus(src []*eth.Attestation) []*Attestation {
 
 func AttsElectraToConsensus(src []*AttestationElectra) ([]*eth.AttestationElectra, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "AttestationsElectra")
 	}
 	err := slice.VerifyMaxLength(src, 8)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "AttestationsElectra")
 	}
 
 	atts := make([]*eth.AttestationElectra, len(src))
 	for i, a := range src {
+		if a == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d]", i))
+		}
 		atts[i], err = a.ToConsensus()
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d]", i))
@@ -1347,11 +1368,11 @@ func AttsElectraFromConsensus(src []*eth.AttestationElectra) []*AttestationElect
 
 func DepositsToConsensus(src []*Deposit) ([]*eth.Deposit, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "Deposits")
 	}
 	err := slice.VerifyMaxLength(src, 16)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "Deposits")
 	}
 
 	deposits := make([]*eth.Deposit, len(src))
@@ -1423,15 +1444,18 @@ func DepositsFromConsensus(src []*eth.Deposit) []*Deposit {
 
 func SignedExitsToConsensus(src []*SignedVoluntaryExit) ([]*eth.SignedVoluntaryExit, error) {
 	if src == nil {
-		return nil, errNilValue
+		return nil, server.NewDecodeError(errNilValue, "SignedVoluntaryExits")
 	}
 	err := slice.VerifyMaxLength(src, 16)
 	if err != nil {
-		return nil, err
+		return nil, server.NewDecodeError(err, "SignedVoluntaryExits")
 	}
 
 	exits := make([]*eth.SignedVoluntaryExit, len(src))
 	for i, e := range src {
+		if e == nil {
+			return nil, server.NewDecodeError(errNilValue, fmt.Sprintf("[%d]", i))
+		}
 		exits[i], err = e.ToConsensus()
 		if err != nil {
 			return nil, server.NewDecodeError(err, fmt.Sprintf("[%d]", i))
@@ -1546,3 +1570,10 @@ func EventChainReorgFromV1(event *ethv1.EventChainReorg) *ChainReorgEvent {
 		ExecutionOptimistic: event.ExecutionOptimistic,
 	}
 }
+
+func SyncAggregateFromConsensus(sa *eth.SyncAggregate) *SyncAggregate {
+	return &SyncAggregate{
+		SyncCommitteeBits:      hexutil.Encode(sa.SyncCommitteeBits),
+		SyncCommitteeSignature: hexutil.Encode(sa.SyncCommitteeSignature),
+	}
+}

api/server/structs/conversions_block_execution.go

@@ -0,0 +1,973 @@
+package structs
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/prysmaticlabs/prysm/v5/api/server"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/container/slice"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+)
+
+// ----------------------------------------------------------------------------
+// Bellatrix
+// ----------------------------------------------------------------------------
+
+func ExecutionPayloadFromConsensus(payload *enginev1.ExecutionPayload) (*ExecutionPayload, error) {
+	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
+	if err != nil {
+		return nil, err
+	}
+	transactions := make([]string, len(payload.Transactions))
+	for i, tx := range payload.Transactions {
+		transactions[i] = hexutil.Encode(tx)
+	}
+
+	return &ExecutionPayload{
+		ParentHash:    hexutil.Encode(payload.ParentHash),
+		FeeRecipient:  hexutil.Encode(payload.FeeRecipient),
+		StateRoot:     hexutil.Encode(payload.StateRoot),
+		ReceiptsRoot:  hexutil.Encode(payload.ReceiptsRoot),
+		LogsBloom:     hexutil.Encode(payload.LogsBloom),
+		PrevRandao:    hexutil.Encode(payload.PrevRandao),
+		BlockNumber:   fmt.Sprintf("%d", payload.BlockNumber),
+		GasLimit:      fmt.Sprintf("%d", payload.GasLimit),
+		GasUsed:       fmt.Sprintf("%d", payload.GasUsed),
+		Timestamp:     fmt.Sprintf("%d", payload.Timestamp),
+		ExtraData:     hexutil.Encode(payload.ExtraData),
+		BaseFeePerGas: baseFeePerGas,
+		BlockHash:     hexutil.Encode(payload.BlockHash),
+		Transactions:  transactions,
+	}, nil
+}
+
+func (e *ExecutionPayload) ToConsensus() (*enginev1.ExecutionPayload, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionPayload")
+	}
+	payloadParentHash, err := bytesutil.DecodeHexWithLength(e.ParentHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ParentHash")
+	}
+	payloadFeeRecipient, err := bytesutil.DecodeHexWithLength(e.FeeRecipient, fieldparams.FeeRecipientLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.FeeRecipient")
+	}
+	payloadStateRoot, err := bytesutil.DecodeHexWithLength(e.StateRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.StateRoot")
+	}
+	payloadReceiptsRoot, err := bytesutil.DecodeHexWithLength(e.ReceiptsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ReceiptsRoot")
+	}
+	payloadLogsBloom, err := bytesutil.DecodeHexWithLength(e.LogsBloom, fieldparams.LogsBloomLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.LogsBloom")
+	}
+	payloadPrevRandao, err := bytesutil.DecodeHexWithLength(e.PrevRandao, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.PrevRandao")
+	}
+	payloadBlockNumber, err := strconv.ParseUint(e.BlockNumber, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlockNumber")
+	}
+	payloadGasLimit, err := strconv.ParseUint(e.GasLimit, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.GasLimit")
+	}
+	payloadGasUsed, err := strconv.ParseUint(e.GasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.GasUsed")
+	}
+	payloadTimestamp, err := strconv.ParseUint(e.Timestamp, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Timestamp")
+	}
+	payloadExtraData, err := bytesutil.DecodeHexWithMaxLength(e.ExtraData, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ExtraData")
+	}
+	payloadBaseFeePerGas, err := bytesutil.Uint256ToSSZBytes(e.BaseFeePerGas)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BaseFeePerGas")
+	}
+	payloadBlockHash, err := bytesutil.DecodeHexWithLength(e.BlockHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlockHash")
+	}
+	err = slice.VerifyMaxLength(e.Transactions, fieldparams.MaxTxsPerPayloadLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Transactions")
+	}
+	payloadTxs := make([][]byte, len(e.Transactions))
+	for i, tx := range e.Transactions {
+		payloadTxs[i], err = bytesutil.DecodeHexWithMaxLength(tx, fieldparams.MaxBytesPerTxLength)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Transactions[%d]", i))
+		}
+	}
+	return &enginev1.ExecutionPayload{
+		ParentHash:    payloadParentHash,
+		FeeRecipient:  payloadFeeRecipient,
+		StateRoot:     payloadStateRoot,
+		ReceiptsRoot:  payloadReceiptsRoot,
+		LogsBloom:     payloadLogsBloom,
+		PrevRandao:    payloadPrevRandao,
+		BlockNumber:   payloadBlockNumber,
+		GasLimit:      payloadGasLimit,
+		GasUsed:       payloadGasUsed,
+		Timestamp:     payloadTimestamp,
+		ExtraData:     payloadExtraData,
+		BaseFeePerGas: payloadBaseFeePerGas,
+		BlockHash:     payloadBlockHash,
+		Transactions:  payloadTxs,
+	}, nil
+}
+
+func ExecutionPayloadHeaderFromConsensus(payload *enginev1.ExecutionPayloadHeader) (*ExecutionPayloadHeader, error) {
+	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ExecutionPayloadHeader{
+		ParentHash:       hexutil.Encode(payload.ParentHash),
+		FeeRecipient:     hexutil.Encode(payload.FeeRecipient),
+		StateRoot:        hexutil.Encode(payload.StateRoot),
+		ReceiptsRoot:     hexutil.Encode(payload.ReceiptsRoot),
+		LogsBloom:        hexutil.Encode(payload.LogsBloom),
+		PrevRandao:       hexutil.Encode(payload.PrevRandao),
+		BlockNumber:      fmt.Sprintf("%d", payload.BlockNumber),
+		GasLimit:         fmt.Sprintf("%d", payload.GasLimit),
+		GasUsed:          fmt.Sprintf("%d", payload.GasUsed),
+		Timestamp:        fmt.Sprintf("%d", payload.Timestamp),
+		ExtraData:        hexutil.Encode(payload.ExtraData),
+		BaseFeePerGas:    baseFeePerGas,
+		BlockHash:        hexutil.Encode(payload.BlockHash),
+		TransactionsRoot: hexutil.Encode(payload.TransactionsRoot),
+	}, nil
+}
+
+func (e *ExecutionPayloadHeader) ToConsensus() (*enginev1.ExecutionPayloadHeader, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionPayloadHeader")
+	}
+	payloadParentHash, err := bytesutil.DecodeHexWithLength(e.ParentHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ParentHash")
+	}
+	payloadFeeRecipient, err := bytesutil.DecodeHexWithLength(e.FeeRecipient, fieldparams.FeeRecipientLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.FeeRecipient")
+	}
+	payloadStateRoot, err := bytesutil.DecodeHexWithLength(e.StateRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.StateRoot")
+	}
+	payloadReceiptsRoot, err := bytesutil.DecodeHexWithLength(e.ReceiptsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ReceiptsRoot")
+	}
+	payloadLogsBloom, err := bytesutil.DecodeHexWithLength(e.LogsBloom, fieldparams.LogsBloomLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.LogsBloom")
+	}
+	payloadPrevRandao, err := bytesutil.DecodeHexWithLength(e.PrevRandao, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.PrevRandao")
+	}
+	payloadBlockNumber, err := strconv.ParseUint(e.BlockNumber, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BlockNumber")
+	}
+	payloadGasLimit, err := strconv.ParseUint(e.GasLimit, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.GasLimit")
+	}
+	payloadGasUsed, err := strconv.ParseUint(e.GasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.GasUsed")
+	}
+	payloadTimestamp, err := strconv.ParseUint(e.Timestamp, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.Timestamp")
+	}
+	payloadExtraData, err := bytesutil.DecodeHexWithMaxLength(e.ExtraData, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ExtraData")
+	}
+	payloadBaseFeePerGas, err := bytesutil.Uint256ToSSZBytes(e.BaseFeePerGas)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BaseFeePerGas")
+	}
+	payloadBlockHash, err := bytesutil.DecodeHexWithLength(e.BlockHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BlockHash")
+	}
+	payloadTxsRoot, err := bytesutil.DecodeHexWithLength(e.TransactionsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.TransactionsRoot")
+	}
+
+	return &enginev1.ExecutionPayloadHeader{
+		ParentHash:       payloadParentHash,
+		FeeRecipient:     payloadFeeRecipient,
+		StateRoot:        payloadStateRoot,
+		ReceiptsRoot:     payloadReceiptsRoot,
+		LogsBloom:        payloadLogsBloom,
+		PrevRandao:       payloadPrevRandao,
+		BlockNumber:      payloadBlockNumber,
+		GasLimit:         payloadGasLimit,
+		GasUsed:          payloadGasUsed,
+		Timestamp:        payloadTimestamp,
+		ExtraData:        payloadExtraData,
+		BaseFeePerGas:    payloadBaseFeePerGas,
+		BlockHash:        payloadBlockHash,
+		TransactionsRoot: payloadTxsRoot,
+	}, nil
+}
+
+// ----------------------------------------------------------------------------
+// Capella
+// ----------------------------------------------------------------------------
+
+func ExecutionPayloadCapellaFromConsensus(payload *enginev1.ExecutionPayloadCapella) (*ExecutionPayloadCapella, error) {
+	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
+	if err != nil {
+		return nil, err
+	}
+	transactions := make([]string, len(payload.Transactions))
+	for i, tx := range payload.Transactions {
+		transactions[i] = hexutil.Encode(tx)
+	}
+
+	return &ExecutionPayloadCapella{
+		ParentHash:    hexutil.Encode(payload.ParentHash),
+		FeeRecipient:  hexutil.Encode(payload.FeeRecipient),
+		StateRoot:     hexutil.Encode(payload.StateRoot),
+		ReceiptsRoot:  hexutil.Encode(payload.ReceiptsRoot),
+		LogsBloom:     hexutil.Encode(payload.LogsBloom),
+		PrevRandao:    hexutil.Encode(payload.PrevRandao),
+		BlockNumber:   fmt.Sprintf("%d", payload.BlockNumber),
+		GasLimit:      fmt.Sprintf("%d", payload.GasLimit),
+		GasUsed:       fmt.Sprintf("%d", payload.GasUsed),
+		Timestamp:     fmt.Sprintf("%d", payload.Timestamp),
+		ExtraData:     hexutil.Encode(payload.ExtraData),
+		BaseFeePerGas: baseFeePerGas,
+		BlockHash:     hexutil.Encode(payload.BlockHash),
+		Transactions:  transactions,
+		Withdrawals:   WithdrawalsFromConsensus(payload.Withdrawals),
+	}, nil
+}
+
+func (e *ExecutionPayloadCapella) ToConsensus() (*enginev1.ExecutionPayloadCapella, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionPayload")
+	}
+	payloadParentHash, err := bytesutil.DecodeHexWithLength(e.ParentHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ParentHash")
+	}
+	payloadFeeRecipient, err := bytesutil.DecodeHexWithLength(e.FeeRecipient, fieldparams.FeeRecipientLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.FeeRecipient")
+	}
+	payloadStateRoot, err := bytesutil.DecodeHexWithLength(e.StateRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.StateRoot")
+	}
+	payloadReceiptsRoot, err := bytesutil.DecodeHexWithLength(e.ReceiptsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ReceiptsRoot")
+	}
+	payloadLogsBloom, err := bytesutil.DecodeHexWithLength(e.LogsBloom, fieldparams.LogsBloomLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.LogsBloom")
+	}
+	payloadPrevRandao, err := bytesutil.DecodeHexWithLength(e.PrevRandao, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.PrevRandao")
+	}
+	payloadBlockNumber, err := strconv.ParseUint(e.BlockNumber, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlockNumber")
+	}
+	payloadGasLimit, err := strconv.ParseUint(e.GasLimit, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.GasLimit")
+	}
+	payloadGasUsed, err := strconv.ParseUint(e.GasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.GasUsed")
+	}
+	payloadTimestamp, err := strconv.ParseUint(e.Timestamp, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Timestamp")
+	}
+	payloadExtraData, err := bytesutil.DecodeHexWithMaxLength(e.ExtraData, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ExtraData")
+	}
+	payloadBaseFeePerGas, err := bytesutil.Uint256ToSSZBytes(e.BaseFeePerGas)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BaseFeePerGas")
+	}
+	payloadBlockHash, err := bytesutil.DecodeHexWithLength(e.BlockHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlockHash")
+	}
+	err = slice.VerifyMaxLength(e.Transactions, fieldparams.MaxTxsPerPayloadLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Transactions")
+	}
+	payloadTxs := make([][]byte, len(e.Transactions))
+	for i, tx := range e.Transactions {
+		payloadTxs[i], err = bytesutil.DecodeHexWithMaxLength(tx, fieldparams.MaxBytesPerTxLength)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Transactions[%d]", i))
+		}
+	}
+	err = slice.VerifyMaxLength(e.Withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Withdrawals")
+	}
+	withdrawals := make([]*enginev1.Withdrawal, len(e.Withdrawals))
+	for i, w := range e.Withdrawals {
+		withdrawalIndex, err := strconv.ParseUint(w.WithdrawalIndex, 10, 64)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].WithdrawalIndex", i))
+		}
+		validatorIndex, err := strconv.ParseUint(w.ValidatorIndex, 10, 64)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].ValidatorIndex", i))
+		}
+		address, err := bytesutil.DecodeHexWithLength(w.ExecutionAddress, common.AddressLength)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].ExecutionAddress", i))
+		}
+		amount, err := strconv.ParseUint(w.Amount, 10, 64)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].Amount", i))
+		}
+		withdrawals[i] = &enginev1.Withdrawal{
+			Index:          withdrawalIndex,
+			ValidatorIndex: primitives.ValidatorIndex(validatorIndex),
+			Address:        address,
+			Amount:         amount,
+		}
+	}
+	return &enginev1.ExecutionPayloadCapella{
+		ParentHash:    payloadParentHash,
+		FeeRecipient:  payloadFeeRecipient,
+		StateRoot:     payloadStateRoot,
+		ReceiptsRoot:  payloadReceiptsRoot,
+		LogsBloom:     payloadLogsBloom,
+		PrevRandao:    payloadPrevRandao,
+		BlockNumber:   payloadBlockNumber,
+		GasLimit:      payloadGasLimit,
+		GasUsed:       payloadGasUsed,
+		Timestamp:     payloadTimestamp,
+		ExtraData:     payloadExtraData,
+		BaseFeePerGas: payloadBaseFeePerGas,
+		BlockHash:     payloadBlockHash,
+		Transactions:  payloadTxs,
+		Withdrawals:   withdrawals,
+	}, nil
+}
+
+func ExecutionPayloadHeaderCapellaFromConsensus(payload *enginev1.ExecutionPayloadHeaderCapella) (*ExecutionPayloadHeaderCapella, error) {
+	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ExecutionPayloadHeaderCapella{
+		ParentHash:       hexutil.Encode(payload.ParentHash),
+		FeeRecipient:     hexutil.Encode(payload.FeeRecipient),
+		StateRoot:        hexutil.Encode(payload.StateRoot),
+		ReceiptsRoot:     hexutil.Encode(payload.ReceiptsRoot),
+		LogsBloom:        hexutil.Encode(payload.LogsBloom),
+		PrevRandao:       hexutil.Encode(payload.PrevRandao),
+		BlockNumber:      fmt.Sprintf("%d", payload.BlockNumber),
+		GasLimit:         fmt.Sprintf("%d", payload.GasLimit),
+		GasUsed:          fmt.Sprintf("%d", payload.GasUsed),
+		Timestamp:        fmt.Sprintf("%d", payload.Timestamp),
+		ExtraData:        hexutil.Encode(payload.ExtraData),
+		BaseFeePerGas:    baseFeePerGas,
+		BlockHash:        hexutil.Encode(payload.BlockHash),
+		TransactionsRoot: hexutil.Encode(payload.TransactionsRoot),
+		WithdrawalsRoot:  hexutil.Encode(payload.WithdrawalsRoot),
+	}, nil
+}
+
+func (e *ExecutionPayloadHeaderCapella) ToConsensus() (*enginev1.ExecutionPayloadHeaderCapella, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionPayloadHeader")
+	}
+	payloadParentHash, err := bytesutil.DecodeHexWithLength(e.ParentHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ParentHash")
+	}
+	payloadFeeRecipient, err := bytesutil.DecodeHexWithLength(e.FeeRecipient, fieldparams.FeeRecipientLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.FeeRecipient")
+	}
+	payloadStateRoot, err := bytesutil.DecodeHexWithLength(e.StateRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.StateRoot")
+	}
+	payloadReceiptsRoot, err := bytesutil.DecodeHexWithLength(e.ReceiptsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ReceiptsRoot")
+	}
+	payloadLogsBloom, err := bytesutil.DecodeHexWithLength(e.LogsBloom, fieldparams.LogsBloomLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.LogsBloom")
+	}
+	payloadPrevRandao, err := bytesutil.DecodeHexWithLength(e.PrevRandao, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.PrevRandao")
+	}
+	payloadBlockNumber, err := strconv.ParseUint(e.BlockNumber, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BlockNumber")
+	}
+	payloadGasLimit, err := strconv.ParseUint(e.GasLimit, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.GasLimit")
+	}
+	payloadGasUsed, err := strconv.ParseUint(e.GasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.GasUsed")
+	}
+	payloadTimestamp, err := strconv.ParseUint(e.Timestamp, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.Timestamp")
+	}
+	payloadExtraData, err := bytesutil.DecodeHexWithMaxLength(e.ExtraData, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ExtraData")
+	}
+	payloadBaseFeePerGas, err := bytesutil.Uint256ToSSZBytes(e.BaseFeePerGas)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BaseFeePerGas")
+	}
+	payloadBlockHash, err := bytesutil.DecodeHexWithMaxLength(e.BlockHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BlockHash")
+	}
+	payloadTxsRoot, err := bytesutil.DecodeHexWithMaxLength(e.TransactionsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.TransactionsRoot")
+	}
+	payloadWithdrawalsRoot, err := bytesutil.DecodeHexWithMaxLength(e.WithdrawalsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.WithdrawalsRoot")
+	}
+	return &enginev1.ExecutionPayloadHeaderCapella{
+		ParentHash:       payloadParentHash,
+		FeeRecipient:     payloadFeeRecipient,
+		StateRoot:        payloadStateRoot,
+		ReceiptsRoot:     payloadReceiptsRoot,
+		LogsBloom:        payloadLogsBloom,
+		PrevRandao:       payloadPrevRandao,
+		BlockNumber:      payloadBlockNumber,
+		GasLimit:         payloadGasLimit,
+		GasUsed:          payloadGasUsed,
+		Timestamp:        payloadTimestamp,
+		ExtraData:        payloadExtraData,
+		BaseFeePerGas:    payloadBaseFeePerGas,
+		BlockHash:        payloadBlockHash,
+		TransactionsRoot: payloadTxsRoot,
+		WithdrawalsRoot:  payloadWithdrawalsRoot,
+	}, nil
+}
+
+// ----------------------------------------------------------------------------
+// Deneb
+// ----------------------------------------------------------------------------
+
+func ExecutionPayloadDenebFromConsensus(payload *enginev1.ExecutionPayloadDeneb) (*ExecutionPayloadDeneb, error) {
+	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
+	if err != nil {
+		return nil, err
+	}
+	transactions := make([]string, len(payload.Transactions))
+	for i, tx := range payload.Transactions {
+		transactions[i] = hexutil.Encode(tx)
+	}
+
+	return &ExecutionPayloadDeneb{
+		ParentHash:    hexutil.Encode(payload.ParentHash),
+		FeeRecipient:  hexutil.Encode(payload.FeeRecipient),
+		StateRoot:     hexutil.Encode(payload.StateRoot),
+		ReceiptsRoot:  hexutil.Encode(payload.ReceiptsRoot),
+		LogsBloom:     hexutil.Encode(payload.LogsBloom),
+		PrevRandao:    hexutil.Encode(payload.PrevRandao),
+		BlockNumber:   fmt.Sprintf("%d", payload.BlockNumber),
+		GasLimit:      fmt.Sprintf("%d", payload.GasLimit),
+		GasUsed:       fmt.Sprintf("%d", payload.GasUsed),
+		Timestamp:     fmt.Sprintf("%d", payload.Timestamp),
+		ExtraData:     hexutil.Encode(payload.ExtraData),
+		BaseFeePerGas: baseFeePerGas,
+		BlockHash:     hexutil.Encode(payload.BlockHash),
+		Transactions:  transactions,
+		Withdrawals:   WithdrawalsFromConsensus(payload.Withdrawals),
+		BlobGasUsed:   fmt.Sprintf("%d", payload.BlobGasUsed),
+		ExcessBlobGas: fmt.Sprintf("%d", payload.ExcessBlobGas),
+	}, nil
+}
+
+func (e *ExecutionPayloadDeneb) ToConsensus() (*enginev1.ExecutionPayloadDeneb, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionPayload")
+	}
+	payloadParentHash, err := bytesutil.DecodeHexWithLength(e.ParentHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ParentHash")
+	}
+	payloadFeeRecipient, err := bytesutil.DecodeHexWithLength(e.FeeRecipient, fieldparams.FeeRecipientLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.FeeRecipient")
+	}
+	payloadStateRoot, err := bytesutil.DecodeHexWithLength(e.StateRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.StateRoot")
+	}
+	payloadReceiptsRoot, err := bytesutil.DecodeHexWithLength(e.ReceiptsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ReceiptsRoot")
+	}
+	payloadLogsBloom, err := bytesutil.DecodeHexWithLength(e.LogsBloom, fieldparams.LogsBloomLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.LogsBloom")
+	}
+	payloadPrevRandao, err := bytesutil.DecodeHexWithLength(e.PrevRandao, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.PrevRandao")
+	}
+	payloadBlockNumber, err := strconv.ParseUint(e.BlockNumber, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlockNumber")
+	}
+	payloadGasLimit, err := strconv.ParseUint(e.GasLimit, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.GasLimit")
+	}
+	payloadGasUsed, err := strconv.ParseUint(e.GasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.GasUsed")
+	}
+	payloadTimestamp, err := strconv.ParseUint(e.Timestamp, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.Timestamp")
+	}
+	payloadExtraData, err := bytesutil.DecodeHexWithMaxLength(e.ExtraData, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ExtraData")
+	}
+	payloadBaseFeePerGas, err := bytesutil.Uint256ToSSZBytes(e.BaseFeePerGas)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BaseFeePerGas")
+	}
+	payloadBlockHash, err := bytesutil.DecodeHexWithLength(e.BlockHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlockHash")
+	}
+	err = slice.VerifyMaxLength(e.Transactions, fieldparams.MaxTxsPerPayloadLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Transactions")
+	}
+	txs := make([][]byte, len(e.Transactions))
+	for i, tx := range e.Transactions {
+		txs[i], err = bytesutil.DecodeHexWithMaxLength(tx, fieldparams.MaxBytesPerTxLength)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Transactions[%d]", i))
+		}
+	}
+	err = slice.VerifyMaxLength(e.Withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.Withdrawals")
+	}
+	withdrawals := make([]*enginev1.Withdrawal, len(e.Withdrawals))
+	for i, w := range e.Withdrawals {
+		withdrawalIndex, err := strconv.ParseUint(w.WithdrawalIndex, 10, 64)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].WithdrawalIndex", i))
+		}
+		validatorIndex, err := strconv.ParseUint(w.ValidatorIndex, 10, 64)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].ValidatorIndex", i))
+		}
+		address, err := bytesutil.DecodeHexWithLength(w.ExecutionAddress, common.AddressLength)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].ExecutionAddress", i))
+		}
+		amount, err := strconv.ParseUint(w.Amount, 10, 64)
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionPayload.Withdrawals[%d].Amount", i))
+		}
+		withdrawals[i] = &enginev1.Withdrawal{
+			Index:          withdrawalIndex,
+			ValidatorIndex: primitives.ValidatorIndex(validatorIndex),
+			Address:        address,
+			Amount:         amount,
+		}
+	}
+
+	payloadBlobGasUsed, err := strconv.ParseUint(e.BlobGasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlobGasUsed")
+	}
+	payloadExcessBlobGas, err := strconv.ParseUint(e.ExcessBlobGas, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ExcessBlobGas")
+	}
+	return &enginev1.ExecutionPayloadDeneb{
+		ParentHash:    payloadParentHash,
+		FeeRecipient:  payloadFeeRecipient,
+		StateRoot:     payloadStateRoot,
+		ReceiptsRoot:  payloadReceiptsRoot,
+		LogsBloom:     payloadLogsBloom,
+		PrevRandao:    payloadPrevRandao,
+		BlockNumber:   payloadBlockNumber,
+		GasLimit:      payloadGasLimit,
+		GasUsed:       payloadGasUsed,
+		Timestamp:     payloadTimestamp,
+		ExtraData:     payloadExtraData,
+		BaseFeePerGas: payloadBaseFeePerGas,
+		BlockHash:     payloadBlockHash,
+		Transactions:  txs,
+		Withdrawals:   withdrawals,
+		BlobGasUsed:   payloadBlobGasUsed,
+		ExcessBlobGas: payloadExcessBlobGas,
+	}, nil
+}
+
+func ExecutionPayloadHeaderDenebFromConsensus(payload *enginev1.ExecutionPayloadHeaderDeneb) (*ExecutionPayloadHeaderDeneb, error) {
+	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ExecutionPayloadHeaderDeneb{
+		ParentHash:       hexutil.Encode(payload.ParentHash),
+		FeeRecipient:     hexutil.Encode(payload.FeeRecipient),
+		StateRoot:        hexutil.Encode(payload.StateRoot),
+		ReceiptsRoot:     hexutil.Encode(payload.ReceiptsRoot),
+		LogsBloom:        hexutil.Encode(payload.LogsBloom),
+		PrevRandao:       hexutil.Encode(payload.PrevRandao),
+		BlockNumber:      fmt.Sprintf("%d", payload.BlockNumber),
+		GasLimit:         fmt.Sprintf("%d", payload.GasLimit),
+		GasUsed:          fmt.Sprintf("%d", payload.GasUsed),
+		Timestamp:        fmt.Sprintf("%d", payload.Timestamp),
+		ExtraData:        hexutil.Encode(payload.ExtraData),
+		BaseFeePerGas:    baseFeePerGas,
+		BlockHash:        hexutil.Encode(payload.BlockHash),
+		TransactionsRoot: hexutil.Encode(payload.TransactionsRoot),
+		WithdrawalsRoot:  hexutil.Encode(payload.WithdrawalsRoot),
+		BlobGasUsed:      fmt.Sprintf("%d", payload.BlobGasUsed),
+		ExcessBlobGas:    fmt.Sprintf("%d", payload.ExcessBlobGas),
+	}, nil
+}
+
+func (e *ExecutionPayloadHeaderDeneb) ToConsensus() (*enginev1.ExecutionPayloadHeaderDeneb, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionPayloadHeader")
+	}
+	payloadParentHash, err := bytesutil.DecodeHexWithLength(e.ParentHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ParentHash")
+	}
+	payloadFeeRecipient, err := bytesutil.DecodeHexWithLength(e.FeeRecipient, fieldparams.FeeRecipientLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.FeeRecipient")
+	}
+	payloadStateRoot, err := bytesutil.DecodeHexWithLength(e.StateRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.StateRoot")
+	}
+	payloadReceiptsRoot, err := bytesutil.DecodeHexWithLength(e.ReceiptsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ReceiptsRoot")
+	}
+	payloadLogsBloom, err := bytesutil.DecodeHexWithLength(e.LogsBloom, fieldparams.LogsBloomLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.LogsBloom")
+	}
+	payloadPrevRandao, err := bytesutil.DecodeHexWithLength(e.PrevRandao, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.PrevRandao")
+	}
+	payloadBlockNumber, err := strconv.ParseUint(e.BlockNumber, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BlockNumber")
+	}
+	payloadGasLimit, err := strconv.ParseUint(e.GasLimit, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.GasLimit")
+	}
+	payloadGasUsed, err := strconv.ParseUint(e.GasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.GasUsed")
+	}
+	payloadTimestamp, err := strconv.ParseUint(e.Timestamp, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.Timestamp")
+	}
+	payloadExtraData, err := bytesutil.DecodeHexWithMaxLength(e.ExtraData, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.ExtraData")
+	}
+	payloadBaseFeePerGas, err := bytesutil.Uint256ToSSZBytes(e.BaseFeePerGas)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BaseFeePerGas")
+	}
+	payloadBlockHash, err := bytesutil.DecodeHexWithLength(e.BlockHash, common.HashLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.BlockHash")
+	}
+	payloadTxsRoot, err := bytesutil.DecodeHexWithLength(e.TransactionsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.TransactionsRoot")
+	}
+	payloadWithdrawalsRoot, err := bytesutil.DecodeHexWithLength(e.WithdrawalsRoot, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayloadHeader.WithdrawalsRoot")
+	}
+	payloadBlobGasUsed, err := strconv.ParseUint(e.BlobGasUsed, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.BlobGasUsed")
+	}
+	payloadExcessBlobGas, err := strconv.ParseUint(e.ExcessBlobGas, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ExecutionPayload.ExcessBlobGas")
+	}
+	return &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       payloadParentHash,
+		FeeRecipient:     payloadFeeRecipient,
+		StateRoot:        payloadStateRoot,
+		ReceiptsRoot:     payloadReceiptsRoot,
+		LogsBloom:        payloadLogsBloom,
+		PrevRandao:       payloadPrevRandao,
+		BlockNumber:      payloadBlockNumber,
+		GasLimit:         payloadGasLimit,
+		GasUsed:          payloadGasUsed,
+		Timestamp:        payloadTimestamp,
+		ExtraData:        payloadExtraData,
+		BaseFeePerGas:    payloadBaseFeePerGas,
+		BlockHash:        payloadBlockHash,
+		TransactionsRoot: payloadTxsRoot,
+		WithdrawalsRoot:  payloadWithdrawalsRoot,
+		BlobGasUsed:      payloadBlobGasUsed,
+		ExcessBlobGas:    payloadExcessBlobGas,
+	}, nil
+}
+
+// ----------------------------------------------------------------------------
+// Electra
+// ----------------------------------------------------------------------------
+
+var (
+	ExecutionPayloadElectraFromConsensus       = ExecutionPayloadDenebFromConsensus
+	ExecutionPayloadHeaderElectraFromConsensus = ExecutionPayloadHeaderDenebFromConsensus
+)
+
+func WithdrawalRequestsFromConsensus(ws []*enginev1.WithdrawalRequest) []*WithdrawalRequest {
+	result := make([]*WithdrawalRequest, len(ws))
+	for i, w := range ws {
+		result[i] = WithdrawalRequestFromConsensus(w)
+	}
+	return result
+}
+
+func WithdrawalRequestFromConsensus(w *enginev1.WithdrawalRequest) *WithdrawalRequest {
+	return &WithdrawalRequest{
+		SourceAddress:   hexutil.Encode(w.SourceAddress),
+		ValidatorPubkey: hexutil.Encode(w.ValidatorPubkey),
+		Amount:          fmt.Sprintf("%d", w.Amount),
+	}
+}
+
+func (w *WithdrawalRequest) ToConsensus() (*enginev1.WithdrawalRequest, error) {
+	if w == nil {
+		return nil, server.NewDecodeError(errNilValue, "WithdrawalRequest")
+	}
+	src, err := bytesutil.DecodeHexWithLength(w.SourceAddress, common.AddressLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "SourceAddress")
+	}
+	pubkey, err := bytesutil.DecodeHexWithLength(w.ValidatorPubkey, fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "ValidatorPubkey")
+	}
+	amount, err := strconv.ParseUint(w.Amount, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Amount")
+	}
+	return &enginev1.WithdrawalRequest{
+		SourceAddress:   src,
+		ValidatorPubkey: pubkey,
+		Amount:          amount,
+	}, nil
+}
+
+func ConsolidationRequestsFromConsensus(cs []*enginev1.ConsolidationRequest) []*ConsolidationRequest {
+	result := make([]*ConsolidationRequest, len(cs))
+	for i, c := range cs {
+		result[i] = ConsolidationRequestFromConsensus(c)
+	}
+	return result
+}
+
+func ConsolidationRequestFromConsensus(c *enginev1.ConsolidationRequest) *ConsolidationRequest {
+	return &ConsolidationRequest{
+		SourceAddress: hexutil.Encode(c.SourceAddress),
+		SourcePubkey:  hexutil.Encode(c.SourcePubkey),
+		TargetPubkey:  hexutil.Encode(c.TargetPubkey),
+	}
+}
+
+func (c *ConsolidationRequest) ToConsensus() (*enginev1.ConsolidationRequest, error) {
+	if c == nil {
+		return nil, server.NewDecodeError(errNilValue, "ConsolidationRequest")
+	}
+	srcAddress, err := bytesutil.DecodeHexWithLength(c.SourceAddress, common.AddressLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "SourceAddress")
+	}
+	srcPubkey, err := bytesutil.DecodeHexWithLength(c.SourcePubkey, fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "SourcePubkey")
+	}
+	targetPubkey, err := bytesutil.DecodeHexWithLength(c.TargetPubkey, fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "TargetPubkey")
+	}
+	return &enginev1.ConsolidationRequest{
+		SourceAddress: srcAddress,
+		SourcePubkey:  srcPubkey,
+		TargetPubkey:  targetPubkey,
+	}, nil
+}
+
+func DepositRequestsFromConsensus(ds []*enginev1.DepositRequest) []*DepositRequest {
+	result := make([]*DepositRequest, len(ds))
+	for i, d := range ds {
+		result[i] = DepositRequestFromConsensus(d)
+	}
+	return result
+}
+
+func DepositRequestFromConsensus(d *enginev1.DepositRequest) *DepositRequest {
+	return &DepositRequest{
+		Pubkey:                hexutil.Encode(d.Pubkey),
+		WithdrawalCredentials: hexutil.Encode(d.WithdrawalCredentials),
+		Amount:                fmt.Sprintf("%d", d.Amount),
+		Signature:             hexutil.Encode(d.Signature),
+		Index:                 fmt.Sprintf("%d", d.Index),
+	}
+}
+
+func (d *DepositRequest) ToConsensus() (*enginev1.DepositRequest, error) {
+	if d == nil {
+		return nil, server.NewDecodeError(errNilValue, "DepositRequest")
+	}
+	pubkey, err := bytesutil.DecodeHexWithLength(d.Pubkey, fieldparams.BLSPubkeyLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Pubkey")
+	}
+	withdrawalCredentials, err := bytesutil.DecodeHexWithLength(d.WithdrawalCredentials, fieldparams.RootLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "WithdrawalCredentials")
+	}
+	amount, err := strconv.ParseUint(d.Amount, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Amount")
+	}
+	sig, err := bytesutil.DecodeHexWithLength(d.Signature, fieldparams.BLSSignatureLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
+	index, err := strconv.ParseUint(d.Index, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Index")
+	}
+	return &enginev1.DepositRequest{
+		Pubkey:                pubkey,
+		WithdrawalCredentials: withdrawalCredentials,
+		Amount:                amount,
+		Signature:             sig,
+		Index:                 index,
+	}, nil
+}
+
+func ExecutionRequestsFromConsensus(er *enginev1.ExecutionRequests) *ExecutionRequests {
+	return &ExecutionRequests{
+		Deposits:       DepositRequestsFromConsensus(er.Deposits),
+		Withdrawals:    WithdrawalRequestsFromConsensus(er.Withdrawals),
+		Consolidations: ConsolidationRequestsFromConsensus(er.Consolidations),
+	}
+}
+
+func (e *ExecutionRequests) ToConsensus() (*enginev1.ExecutionRequests, error) {
+	if e == nil {
+		return nil, server.NewDecodeError(errNilValue, "ExecutionRequests")
+	}
+	var err error
+	if err = slice.VerifyMaxLength(e.Deposits, params.BeaconConfig().MaxDepositRequestsPerPayload); err != nil {
+		return nil, err
+	}
+	depositRequests := make([]*enginev1.DepositRequest, len(e.Deposits))
+	for i, d := range e.Deposits {
+		depositRequests[i], err = d.ToConsensus()
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionRequests.Deposits[%d]", i))
+		}
+	}
+
+	if err = slice.VerifyMaxLength(e.Withdrawals, params.BeaconConfig().MaxWithdrawalRequestsPerPayload); err != nil {
+		return nil, err
+	}
+	withdrawalRequests := make([]*enginev1.WithdrawalRequest, len(e.Withdrawals))
+	for i, w := range e.Withdrawals {
+		withdrawalRequests[i], err = w.ToConsensus()
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionRequests.Withdrawals[%d]", i))
+		}
+	}
+
+	if err = slice.VerifyMaxLength(e.Consolidations, params.BeaconConfig().MaxConsolidationsRequestsPerPayload); err != nil {
+		return nil, err
+	}
+	consolidationRequests := make([]*enginev1.ConsolidationRequest, len(e.Consolidations))
+	for i, c := range e.Consolidations {
+		consolidationRequests[i], err = c.ToConsensus()
+		if err != nil {
+			return nil, server.NewDecodeError(err, fmt.Sprintf("ExecutionRequests.Consolidations[%d]", i))
+		}
+	}
+	return &enginev1.ExecutionRequests{
+		Deposits:       depositRequests,
+		Withdrawals:    withdrawalRequests,
+		Consolidations: consolidationRequests,
+	}, nil
+}
+
+// ----------------------------------------------------------------------------
+// Fulu
+// ----------------------------------------------------------------------------
+
+var (
+	ExecutionPayloadFuluFromConsensus       = ExecutionPayloadDenebFromConsensus
+	ExecutionPayloadHeaderFuluFromConsensus = ExecutionPayloadHeaderDenebFromConsensus
+	BeaconBlockFuluFromConsensus            = BeaconBlockElectraFromConsensus
+)

api/server/structs/conversions_block_execution_test.go

@@ -0,0 +1,563 @@
+package structs
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func fillByteSlice(sliceLength int, value byte) []byte {
+	bytes := make([]byte, sliceLength)
+
+	for index := range bytes {
+		bytes[index] = value
+	}
+
+	return bytes
+}
+
+// TestExecutionPayloadFromConsensus_HappyPath checks the
+// ExecutionPayloadFromConsensus function under normal conditions.
+func TestExecutionPayloadFromConsensus_HappyPath(t *testing.T) {
+	consensusPayload := &enginev1.ExecutionPayload{
+		ParentHash:    fillByteSlice(common.HashLength, 0xaa),
+		FeeRecipient:  fillByteSlice(20, 0xbb),
+		StateRoot:     fillByteSlice(32, 0xcc),
+		ReceiptsRoot:  fillByteSlice(32, 0xdd),
+		LogsBloom:     fillByteSlice(256, 0xee),
+		PrevRandao:    fillByteSlice(32, 0xff),
+		BlockNumber:   12345,
+		GasLimit:      15000000,
+		GasUsed:       8000000,
+		Timestamp:     1680000000,
+		ExtraData:     fillByteSlice(8, 0x11),
+		BaseFeePerGas: fillByteSlice(32, 0x01),
+		BlockHash:     fillByteSlice(common.HashLength, 0x22),
+		Transactions: [][]byte{
+			fillByteSlice(10, 0x33),
+			fillByteSlice(10, 0x44),
+		},
+	}
+
+	result, err := ExecutionPayloadFromConsensus(consensusPayload)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, hexutil.Encode(consensusPayload.ParentHash), result.ParentHash)
+	require.Equal(t, hexutil.Encode(consensusPayload.FeeRecipient), result.FeeRecipient)
+	require.Equal(t, hexutil.Encode(consensusPayload.StateRoot), result.StateRoot)
+	require.Equal(t, hexutil.Encode(consensusPayload.ReceiptsRoot), result.ReceiptsRoot)
+	require.Equal(t, fmt.Sprintf("%d", consensusPayload.BlockNumber), result.BlockNumber)
+}
+
+// TestExecutionPayload_ToConsensus_HappyPath checks the
+// (*ExecutionPayload).ToConsensus function under normal conditions.
+func TestExecutionPayload_ToConsensus_HappyPath(t *testing.T) {
+	payload := &ExecutionPayload{
+		ParentHash:    hexutil.Encode(fillByteSlice(common.HashLength, 0xaa)),
+		FeeRecipient:  hexutil.Encode(fillByteSlice(20, 0xbb)),
+		StateRoot:     hexutil.Encode(fillByteSlice(32, 0xcc)),
+		ReceiptsRoot:  hexutil.Encode(fillByteSlice(32, 0xdd)),
+		LogsBloom:     hexutil.Encode(fillByteSlice(256, 0xee)),
+		PrevRandao:    hexutil.Encode(fillByteSlice(32, 0xff)),
+		BlockNumber:   "12345",
+		GasLimit:      "15000000",
+		GasUsed:       "8000000",
+		Timestamp:     "1680000000",
+		ExtraData:     "0x11111111",
+		BaseFeePerGas: "1234",
+		BlockHash:     hexutil.Encode(fillByteSlice(common.HashLength, 0x22)),
+		Transactions: []string{
+			hexutil.Encode(fillByteSlice(10, 0x33)),
+			hexutil.Encode(fillByteSlice(10, 0x44)),
+		},
+	}
+
+	result, err := payload.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, result.ParentHash, fillByteSlice(common.HashLength, 0xaa))
+	require.DeepEqual(t, result.FeeRecipient, fillByteSlice(20, 0xbb))
+	require.DeepEqual(t, result.StateRoot, fillByteSlice(32, 0xcc))
+}
+
+// TestExecutionPayloadHeaderFromConsensus_HappyPath checks the
+// ExecutionPayloadHeaderFromConsensus function under normal conditions.
+func TestExecutionPayloadHeaderFromConsensus_HappyPath(t *testing.T) {
+	consensusHeader := &enginev1.ExecutionPayloadHeader{
+		ParentHash:       fillByteSlice(common.HashLength, 0xaa),
+		FeeRecipient:     fillByteSlice(20, 0xbb),
+		StateRoot:        fillByteSlice(32, 0xcc),
+		ReceiptsRoot:     fillByteSlice(32, 0xdd),
+		LogsBloom:        fillByteSlice(256, 0xee),
+		PrevRandao:       fillByteSlice(32, 0xff),
+		BlockNumber:      9999,
+		GasLimit:         5000000,
+		GasUsed:          2500000,
+		Timestamp:        1111111111,
+		ExtraData:        fillByteSlice(4, 0x12),
+		BaseFeePerGas:    fillByteSlice(32, 0x34),
+		BlockHash:        fillByteSlice(common.HashLength, 0x56),
+		TransactionsRoot: fillByteSlice(32, 0x78),
+	}
+
+	result, err := ExecutionPayloadHeaderFromConsensus(consensusHeader)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, hexutil.Encode(consensusHeader.ParentHash), result.ParentHash)
+	require.Equal(t, fmt.Sprintf("%d", consensusHeader.BlockNumber), result.BlockNumber)
+}
+
+// TestExecutionPayloadHeader_ToConsensus_HappyPath checks the
+// (*ExecutionPayloadHeader).ToConsensus function under normal conditions.
+func TestExecutionPayloadHeader_ToConsensus_HappyPath(t *testing.T) {
+	header := &ExecutionPayloadHeader{
+		ParentHash:       hexutil.Encode(fillByteSlice(common.HashLength, 0xaa)),
+		FeeRecipient:     hexutil.Encode(fillByteSlice(20, 0xbb)),
+		StateRoot:        hexutil.Encode(fillByteSlice(32, 0xcc)),
+		ReceiptsRoot:     hexutil.Encode(fillByteSlice(32, 0xdd)),
+		LogsBloom:        hexutil.Encode(fillByteSlice(256, 0xee)),
+		PrevRandao:       hexutil.Encode(fillByteSlice(32, 0xff)),
+		BlockNumber:      "9999",
+		GasLimit:         "5000000",
+		GasUsed:          "2500000",
+		Timestamp:        "1111111111",
+		ExtraData:        "0x1234abcd",
+		BaseFeePerGas:    "1234",
+		BlockHash:        hexutil.Encode(fillByteSlice(common.HashLength, 0x56)),
+		TransactionsRoot: hexutil.Encode(fillByteSlice(32, 0x78)),
+	}
+
+	result, err := header.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, hexutil.Encode(result.ParentHash), header.ParentHash)
+	require.DeepEqual(t, hexutil.Encode(result.FeeRecipient), header.FeeRecipient)
+	require.DeepEqual(t, hexutil.Encode(result.StateRoot), header.StateRoot)
+}
+
+// TestExecutionPayloadCapellaFromConsensus_HappyPath checks the
+// ExecutionPayloadCapellaFromConsensus function under normal conditions.
+func TestExecutionPayloadCapellaFromConsensus_HappyPath(t *testing.T) {
+	capellaPayload := &enginev1.ExecutionPayloadCapella{
+		ParentHash:    fillByteSlice(common.HashLength, 0xaa),
+		FeeRecipient:  fillByteSlice(20, 0xbb),
+		StateRoot:     fillByteSlice(32, 0xcc),
+		ReceiptsRoot:  fillByteSlice(32, 0xdd),
+		LogsBloom:     fillByteSlice(256, 0xee),
+		PrevRandao:    fillByteSlice(32, 0xff),
+		BlockNumber:   123,
+		GasLimit:      9876543,
+		GasUsed:       1234567,
+		Timestamp:     5555555,
+		ExtraData:     fillByteSlice(6, 0x11),
+		BaseFeePerGas: fillByteSlice(32, 0x22),
+		BlockHash:     fillByteSlice(common.HashLength, 0x33),
+		Transactions: [][]byte{
+			fillByteSlice(5, 0x44),
+		},
+		Withdrawals: []*enginev1.Withdrawal{
+			{
+				Index:          1,
+				ValidatorIndex: 2,
+				Address:        fillByteSlice(20, 0xaa),
+				Amount:         100,
+			},
+		},
+	}
+
+	result, err := ExecutionPayloadCapellaFromConsensus(capellaPayload)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, hexutil.Encode(capellaPayload.ParentHash), result.ParentHash)
+	require.Equal(t, len(capellaPayload.Transactions), len(result.Transactions))
+	require.Equal(t, len(capellaPayload.Withdrawals), len(result.Withdrawals))
+}
+
+// TestExecutionPayloadCapella_ToConsensus_HappyPath checks the
+// (*ExecutionPayloadCapella).ToConsensus function under normal conditions.
+func TestExecutionPayloadCapella_ToConsensus_HappyPath(t *testing.T) {
+	capella := &ExecutionPayloadCapella{
+		ParentHash:    hexutil.Encode(fillByteSlice(common.HashLength, 0xaa)),
+		FeeRecipient:  hexutil.Encode(fillByteSlice(20, 0xbb)),
+		StateRoot:     hexutil.Encode(fillByteSlice(32, 0xcc)),
+		ReceiptsRoot:  hexutil.Encode(fillByteSlice(32, 0xdd)),
+		LogsBloom:     hexutil.Encode(fillByteSlice(256, 0xee)),
+		PrevRandao:    hexutil.Encode(fillByteSlice(32, 0xff)),
+		BlockNumber:   "123",
+		GasLimit:      "9876543",
+		GasUsed:       "1234567",
+		Timestamp:     "5555555",
+		ExtraData:     hexutil.Encode(fillByteSlice(6, 0x11)),
+		BaseFeePerGas: "1234",
+		BlockHash:     hexutil.Encode(fillByteSlice(common.HashLength, 0x33)),
+		Transactions: []string{
+			hexutil.Encode(fillByteSlice(5, 0x44)),
+		},
+		Withdrawals: []*Withdrawal{
+			{
+				WithdrawalIndex:  "1",
+				ValidatorIndex:   "2",
+				ExecutionAddress: hexutil.Encode(fillByteSlice(20, 0xaa)),
+				Amount:           "100",
+			},
+		},
+	}
+
+	result, err := capella.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, hexutil.Encode(result.ParentHash), capella.ParentHash)
+	require.DeepEqual(t, hexutil.Encode(result.FeeRecipient), capella.FeeRecipient)
+	require.DeepEqual(t, hexutil.Encode(result.StateRoot), capella.StateRoot)
+}
+
+// TestExecutionPayloadDenebFromConsensus_HappyPath checks the
+// ExecutionPayloadDenebFromConsensus function under normal conditions.
+func TestExecutionPayloadDenebFromConsensus_HappyPath(t *testing.T) {
+	denebPayload := &enginev1.ExecutionPayloadDeneb{
+		ParentHash:    fillByteSlice(common.HashLength, 0xaa),
+		FeeRecipient:  fillByteSlice(20, 0xbb),
+		StateRoot:     fillByteSlice(32, 0xcc),
+		ReceiptsRoot:  fillByteSlice(32, 0xdd),
+		LogsBloom:     fillByteSlice(256, 0xee),
+		PrevRandao:    fillByteSlice(32, 0xff),
+		BlockNumber:   999,
+		GasLimit:      2222222,
+		GasUsed:       1111111,
+		Timestamp:     666666,
+		ExtraData:     fillByteSlice(6, 0x11),
+		BaseFeePerGas: fillByteSlice(32, 0x22),
+		BlockHash:     fillByteSlice(common.HashLength, 0x33),
+		Transactions: [][]byte{
+			fillByteSlice(5, 0x44),
+		},
+		Withdrawals: []*enginev1.Withdrawal{
+			{
+				Index:          1,
+				ValidatorIndex: 2,
+				Address:        fillByteSlice(20, 0xaa),
+				Amount:         100,
+			},
+		},
+		BlobGasUsed:   1234,
+		ExcessBlobGas: 5678,
+	}
+
+	result, err := ExecutionPayloadDenebFromConsensus(denebPayload)
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(denebPayload.ParentHash), result.ParentHash)
+	require.Equal(t, len(denebPayload.Transactions), len(result.Transactions))
+	require.Equal(t, len(denebPayload.Withdrawals), len(result.Withdrawals))
+	require.Equal(t, "1234", result.BlobGasUsed)
+	require.Equal(t, fmt.Sprintf("%d", denebPayload.BlockNumber), result.BlockNumber)
+}
+
+// TestExecutionPayloadDeneb_ToConsensus_HappyPath checks the
+// (*ExecutionPayloadDeneb).ToConsensus function under normal conditions.
+func TestExecutionPayloadDeneb_ToConsensus_HappyPath(t *testing.T) {
+	deneb := &ExecutionPayloadDeneb{
+		ParentHash:    hexutil.Encode(fillByteSlice(common.HashLength, 0xaa)),
+		FeeRecipient:  hexutil.Encode(fillByteSlice(20, 0xbb)),
+		StateRoot:     hexutil.Encode(fillByteSlice(32, 0xcc)),
+		ReceiptsRoot:  hexutil.Encode(fillByteSlice(32, 0xdd)),
+		LogsBloom:     hexutil.Encode(fillByteSlice(256, 0xee)),
+		PrevRandao:    hexutil.Encode(fillByteSlice(32, 0xff)),
+		BlockNumber:   "999",
+		GasLimit:      "2222222",
+		GasUsed:       "1111111",
+		Timestamp:     "666666",
+		ExtraData:     hexutil.Encode(fillByteSlice(6, 0x11)),
+		BaseFeePerGas: "1234",
+		BlockHash:     hexutil.Encode(fillByteSlice(common.HashLength, 0x33)),
+		Transactions: []string{
+			hexutil.Encode(fillByteSlice(5, 0x44)),
+		},
+		Withdrawals: []*Withdrawal{
+			{
+				WithdrawalIndex:  "1",
+				ValidatorIndex:   "2",
+				ExecutionAddress: hexutil.Encode(fillByteSlice(20, 0xaa)),
+				Amount:           "100",
+			},
+		},
+		BlobGasUsed:   "1234",
+		ExcessBlobGas: "5678",
+	}
+
+	result, err := deneb.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, hexutil.Encode(result.ParentHash), deneb.ParentHash)
+	require.DeepEqual(t, hexutil.Encode(result.FeeRecipient), deneb.FeeRecipient)
+	require.Equal(t, result.BlockNumber, uint64(999))
+}
+
+func TestExecutionPayloadHeaderCapellaFromConsensus_HappyPath(t *testing.T) {
+	capellaHeader := &enginev1.ExecutionPayloadHeaderCapella{
+		ParentHash:       fillByteSlice(common.HashLength, 0xaa),
+		FeeRecipient:     fillByteSlice(20, 0xbb),
+		StateRoot:        fillByteSlice(32, 0xcc),
+		ReceiptsRoot:     fillByteSlice(32, 0xdd),
+		LogsBloom:        fillByteSlice(256, 0xee),
+		PrevRandao:       fillByteSlice(32, 0xff),
+		BlockNumber:      555,
+		GasLimit:         1111111,
+		GasUsed:          222222,
+		Timestamp:        3333333333,
+		ExtraData:        fillByteSlice(4, 0x12),
+		BaseFeePerGas:    fillByteSlice(32, 0x34),
+		BlockHash:        fillByteSlice(common.HashLength, 0x56),
+		TransactionsRoot: fillByteSlice(32, 0x78),
+		WithdrawalsRoot:  fillByteSlice(32, 0x99),
+	}
+
+	result, err := ExecutionPayloadHeaderCapellaFromConsensus(capellaHeader)
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(capellaHeader.ParentHash), result.ParentHash)
+	require.DeepEqual(t, hexutil.Encode(capellaHeader.WithdrawalsRoot), result.WithdrawalsRoot)
+}
+
+func TestExecutionPayloadHeaderCapella_ToConsensus_HappyPath(t *testing.T) {
+	header := &ExecutionPayloadHeaderCapella{
+		ParentHash:       hexutil.Encode(fillByteSlice(common.HashLength, 0xaa)),
+		FeeRecipient:     hexutil.Encode(fillByteSlice(20, 0xbb)),
+		StateRoot:        hexutil.Encode(fillByteSlice(32, 0xcc)),
+		ReceiptsRoot:     hexutil.Encode(fillByteSlice(32, 0xdd)),
+		LogsBloom:        hexutil.Encode(fillByteSlice(256, 0xee)),
+		PrevRandao:       hexutil.Encode(fillByteSlice(32, 0xff)),
+		BlockNumber:      "555",
+		GasLimit:         "1111111",
+		GasUsed:          "222222",
+		Timestamp:        "3333333333",
+		ExtraData:        "0x1234abcd",
+		BaseFeePerGas:    "1234",
+		BlockHash:        hexutil.Encode(fillByteSlice(common.HashLength, 0x56)),
+		TransactionsRoot: hexutil.Encode(fillByteSlice(32, 0x78)),
+		WithdrawalsRoot:  hexutil.Encode(fillByteSlice(32, 0x99)),
+	}
+
+	result, err := header.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, hexutil.Encode(result.ParentHash), header.ParentHash)
+	require.DeepEqual(t, hexutil.Encode(result.FeeRecipient), header.FeeRecipient)
+	require.DeepEqual(t, hexutil.Encode(result.StateRoot), header.StateRoot)
+	require.DeepEqual(t, hexutil.Encode(result.ReceiptsRoot), header.ReceiptsRoot)
+	require.DeepEqual(t, hexutil.Encode(result.WithdrawalsRoot), header.WithdrawalsRoot)
+}
+
+func TestExecutionPayloadHeaderDenebFromConsensus_HappyPath(t *testing.T) {
+	denebHeader := &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       fillByteSlice(common.HashLength, 0xaa),
+		FeeRecipient:     fillByteSlice(20, 0xbb),
+		StateRoot:        fillByteSlice(32, 0xcc),
+		ReceiptsRoot:     fillByteSlice(32, 0xdd),
+		LogsBloom:        fillByteSlice(256, 0xee),
+		PrevRandao:       fillByteSlice(32, 0xff),
+		BlockNumber:      999,
+		GasLimit:         5000000,
+		GasUsed:          2500000,
+		Timestamp:        4444444444,
+		ExtraData:        fillByteSlice(4, 0x12),
+		BaseFeePerGas:    fillByteSlice(32, 0x34),
+		BlockHash:        fillByteSlice(common.HashLength, 0x56),
+		TransactionsRoot: fillByteSlice(32, 0x78),
+		WithdrawalsRoot:  fillByteSlice(32, 0x99),
+		BlobGasUsed:      1234,
+		ExcessBlobGas:    5678,
+	}
+
+	result, err := ExecutionPayloadHeaderDenebFromConsensus(denebHeader)
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(denebHeader.ParentHash), result.ParentHash)
+	require.DeepEqual(t, hexutil.Encode(denebHeader.FeeRecipient), result.FeeRecipient)
+	require.DeepEqual(t, hexutil.Encode(denebHeader.StateRoot), result.StateRoot)
+	require.DeepEqual(t, fmt.Sprintf("%d", denebHeader.BlobGasUsed), result.BlobGasUsed)
+}
+
+func TestExecutionPayloadHeaderDeneb_ToConsensus_HappyPath(t *testing.T) {
+	header := &ExecutionPayloadHeaderDeneb{
+		ParentHash:       hexutil.Encode(fillByteSlice(common.HashLength, 0xaa)),
+		FeeRecipient:     hexutil.Encode(fillByteSlice(20, 0xbb)),
+		StateRoot:        hexutil.Encode(fillByteSlice(32, 0xcc)),
+		ReceiptsRoot:     hexutil.Encode(fillByteSlice(32, 0xdd)),
+		LogsBloom:        hexutil.Encode(fillByteSlice(256, 0xee)),
+		PrevRandao:       hexutil.Encode(fillByteSlice(32, 0xff)),
+		BlockNumber:      "999",
+		GasLimit:         "5000000",
+		GasUsed:          "2500000",
+		Timestamp:        "4444444444",
+		ExtraData:        "0x1234abcd",
+		BaseFeePerGas:    "1234",
+		BlockHash:        hexutil.Encode(fillByteSlice(common.HashLength, 0x56)),
+		TransactionsRoot: hexutil.Encode(fillByteSlice(32, 0x78)),
+		WithdrawalsRoot:  hexutil.Encode(fillByteSlice(32, 0x99)),
+		BlobGasUsed:      "1234",
+		ExcessBlobGas:    "5678",
+	}
+
+	result, err := header.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, hexutil.Encode(result.ParentHash), header.ParentHash)
+	require.DeepEqual(t, result.BlobGasUsed, uint64(1234))
+	require.DeepEqual(t, result.ExcessBlobGas, uint64(5678))
+	require.DeepEqual(t, result.BlockNumber, uint64(999))
+}
+
+func TestWithdrawalRequestsFromConsensus_HappyPath(t *testing.T) {
+	consensusRequests := []*enginev1.WithdrawalRequest{
+		{
+			SourceAddress:   fillByteSlice(20, 0xbb),
+			ValidatorPubkey: fillByteSlice(48, 0xbb),
+			Amount:          12345,
+		},
+		{
+			SourceAddress:   fillByteSlice(20, 0xcc),
+			ValidatorPubkey: fillByteSlice(48, 0xcc),
+			Amount:          54321,
+		},
+	}
+
+	result := WithdrawalRequestsFromConsensus(consensusRequests)
+	require.DeepEqual(t, len(result), len(consensusRequests))
+	require.DeepEqual(t, result[0].Amount, fmt.Sprintf("%d", consensusRequests[0].Amount))
+}
+
+func TestWithdrawalRequestFromConsensus_HappyPath(t *testing.T) {
+	req := &enginev1.WithdrawalRequest{
+		SourceAddress:   fillByteSlice(20, 0xbb),
+		ValidatorPubkey: fillByteSlice(48, 0xbb),
+		Amount:          42,
+	}
+	result := WithdrawalRequestFromConsensus(req)
+	require.NotNil(t, result)
+	require.DeepEqual(t, result.SourceAddress, hexutil.Encode(fillByteSlice(20, 0xbb)))
+}
+
+func TestWithdrawalRequest_ToConsensus_HappyPath(t *testing.T) {
+	withdrawalReq := &WithdrawalRequest{
+		SourceAddress:   hexutil.Encode(fillByteSlice(20, 111)),
+		ValidatorPubkey: hexutil.Encode(fillByteSlice(48, 123)),
+		Amount:          "12345",
+	}
+	result, err := withdrawalReq.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, result.Amount, uint64(12345))
+}
+
+func TestConsolidationRequestsFromConsensus_HappyPath(t *testing.T) {
+	consensusRequests := []*enginev1.ConsolidationRequest{
+		{
+			SourceAddress: fillByteSlice(20, 111),
+			SourcePubkey:  fillByteSlice(48, 112),
+			TargetPubkey:  fillByteSlice(48, 113),
+		},
+	}
+	result := ConsolidationRequestsFromConsensus(consensusRequests)
+	require.DeepEqual(t, len(result), len(consensusRequests))
+	require.DeepEqual(t, result[0].SourceAddress, "0x6f6f6f6f6f6f6f6f6f6f6f6f6f6f6f6f6f6f6f6f")
+}
+
+func TestDepositRequestsFromConsensus_HappyPath(t *testing.T) {
+	ds := []*enginev1.DepositRequest{
+		{
+			Pubkey:                fillByteSlice(48, 0xbb),
+			WithdrawalCredentials: fillByteSlice(32, 0xdd),
+			Amount:                98765,
+			Signature:             fillByteSlice(96, 0xff),
+			Index:                 111,
+		},
+	}
+	result := DepositRequestsFromConsensus(ds)
+	require.DeepEqual(t, len(result), len(ds))
+	require.DeepEqual(t, result[0].Amount, "98765")
+}
+
+func TestDepositRequest_ToConsensus_HappyPath(t *testing.T) {
+	req := &DepositRequest{
+		Pubkey:                hexutil.Encode(fillByteSlice(48, 0xbb)),
+		WithdrawalCredentials: hexutil.Encode(fillByteSlice(32, 0xaa)),
+		Amount:                "123",
+		Signature:             hexutil.Encode(fillByteSlice(96, 0xdd)),
+		Index:                 "456",
+	}
+
+	result, err := req.ToConsensus()
+	require.NoError(t, err)
+	require.DeepEqual(t, result.Amount, uint64(123))
+	require.DeepEqual(t, result.Signature, fillByteSlice(96, 0xdd))
+}
+
+func TestExecutionRequestsFromConsensus_HappyPath(t *testing.T) {
+	er := &enginev1.ExecutionRequests{
+		Deposits: []*enginev1.DepositRequest{
+			{
+				Pubkey:                fillByteSlice(48, 0xba),
+				WithdrawalCredentials: fillByteSlice(32, 0xaa),
+				Amount:                33,
+				Signature:             fillByteSlice(96, 0xff),
+				Index:                 44,
+			},
+		},
+		Withdrawals: []*enginev1.WithdrawalRequest{
+			{
+				SourceAddress:   fillByteSlice(20, 0xaa),
+				ValidatorPubkey: fillByteSlice(48, 0xba),
+				Amount:          555,
+			},
+		},
+		Consolidations: []*enginev1.ConsolidationRequest{
+			{
+				SourceAddress: fillByteSlice(20, 0xdd),
+				SourcePubkey:  fillByteSlice(48, 0xdd),
+				TargetPubkey:  fillByteSlice(48, 0xcc),
+			},
+		},
+	}
+
+	result := ExecutionRequestsFromConsensus(er)
+	require.NotNil(t, result)
+	require.Equal(t, 1, len(result.Deposits))
+	require.Equal(t, "33", result.Deposits[0].Amount)
+	require.Equal(t, 1, len(result.Withdrawals))
+	require.Equal(t, "555", result.Withdrawals[0].Amount)
+	require.Equal(t, 1, len(result.Consolidations))
+	require.Equal(t, "0xcccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc", result.Consolidations[0].TargetPubkey)
+}
+
+func TestExecutionRequests_ToConsensus_HappyPath(t *testing.T) {
+	execReq := &ExecutionRequests{
+		Deposits: []*DepositRequest{
+			{
+				Pubkey:                hexutil.Encode(fillByteSlice(48, 0xbb)),
+				WithdrawalCredentials: hexutil.Encode(fillByteSlice(32, 0xaa)),
+				Amount:                "33",
+				Signature:             hexutil.Encode(fillByteSlice(96, 0xff)),
+				Index:                 "44",
+			},
+		},
+		Withdrawals: []*WithdrawalRequest{
+			{
+				SourceAddress:   hexutil.Encode(fillByteSlice(20, 0xdd)),
+				ValidatorPubkey: hexutil.Encode(fillByteSlice(48, 0xbb)),
+				Amount:          "555",
+			},
+		},
+		Consolidations: []*ConsolidationRequest{
+			{
+				SourceAddress: hexutil.Encode(fillByteSlice(20, 0xcc)),
+				SourcePubkey:  hexutil.Encode(fillByteSlice(48, 0xbb)),
+				TargetPubkey:  hexutil.Encode(fillByteSlice(48, 0xcc)),
+			},
+		},
+	}
+
+	result, err := execReq.ToConsensus()
+	require.NoError(t, err)
+
+	require.Equal(t, 1, len(result.Deposits))
+	require.Equal(t, uint64(33), result.Deposits[0].Amount)
+	require.Equal(t, 1, len(result.Withdrawals))
+	require.Equal(t, uint64(555), result.Withdrawals[0].Amount)
+	require.Equal(t, 1, len(result.Consolidations))
+	require.DeepEqual(t, fillByteSlice(48, 0xcc), result.Consolidations[0].TargetPubkey)
+}

api/server/structs/conversions_lightclient.go

@@ -3,125 +3,227 @@ package structs
 import (
 	"encoding/json"
 	"fmt"
-	"strconv"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
-	v2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-	"github.com/prysmaticlabs/prysm/v5/proto/migration"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )
 
-func LightClientUpdateFromConsensus(update *v2.LightClientUpdate) (*LightClientUpdate, error) {
-	attestedHeader, err := lightClientHeaderContainerToJSON(update.AttestedHeader)
+func LightClientUpdateFromConsensus(update interfaces.LightClientUpdate) (*LightClientUpdate, error) {
+	attestedHeader, err := lightClientHeaderToJSON(update.AttestedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal attested light client header")
 	}
-	finalizedHeader, err := lightClientHeaderContainerToJSON(update.FinalizedHeader)
+	finalizedHeader, err := lightClientHeaderToJSON(update.FinalizedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal finalized light client header")
 	}
 
+	var scBranch [][32]byte
+	var finalityBranch [][32]byte
+	if update.Version() >= version.Electra {
+		scb, err := update.NextSyncCommitteeBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = scb[:]
+		fb, err := update.FinalityBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = fb[:]
+	} else {
+		scb, err := update.NextSyncCommitteeBranch()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = scb[:]
+		fb, err := update.FinalityBranch()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = fb[:]
+	}
+
 	return &LightClientUpdate{
 		AttestedHeader:          attestedHeader,
-		NextSyncCommittee:       SyncCommitteeFromConsensus(migration.V2SyncCommitteeToV1Alpha1(update.NextSyncCommittee)),
-		NextSyncCommitteeBranch: branchToJSON(update.NextSyncCommitteeBranch),
+		NextSyncCommittee:       SyncCommitteeFromConsensus(update.NextSyncCommittee()),
+		NextSyncCommitteeBranch: branchToJSON(scBranch),
 		FinalizedHeader:         finalizedHeader,
-		FinalityBranch:          branchToJSON(update.FinalityBranch),
-		SyncAggregate:           syncAggregateToJSON(update.SyncAggregate),
-		SignatureSlot:           strconv.FormatUint(uint64(update.SignatureSlot), 10),
+		FinalityBranch:          branchToJSON(finalityBranch),
+		SyncAggregate:           SyncAggregateFromConsensus(update.SyncAggregate()),
+		SignatureSlot:           fmt.Sprintf("%d", update.SignatureSlot()),
 	}, nil
 }
 
-func LightClientFinalityUpdateFromConsensus(update *v2.LightClientFinalityUpdate) (*LightClientFinalityUpdate, error) {
-	attestedHeader, err := lightClientHeaderContainerToJSON(update.AttestedHeader)
+func LightClientFinalityUpdateFromConsensus(update interfaces.LightClientFinalityUpdate) (*LightClientFinalityUpdate, error) {
+	attestedHeader, err := lightClientHeaderToJSON(update.AttestedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal attested light client header")
 	}
-	finalizedHeader, err := lightClientHeaderContainerToJSON(update.FinalizedHeader)
+	finalizedHeader, err := lightClientHeaderToJSON(update.FinalizedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal finalized light client header")
 	}
 
+	var finalityBranch [][32]byte
+	if update.Version() >= version.Electra {
+		b, err := update.FinalityBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = b[:]
+	} else {
+		b, err := update.FinalityBranch()
+		if err != nil {
+			return nil, err
+		}
+		finalityBranch = b[:]
+	}
+
 	return &LightClientFinalityUpdate{
 		AttestedHeader:  attestedHeader,
 		FinalizedHeader: finalizedHeader,
-		FinalityBranch:  branchToJSON(update.FinalityBranch),
-		SyncAggregate:   syncAggregateToJSON(update.SyncAggregate),
-		SignatureSlot:   strconv.FormatUint(uint64(update.SignatureSlot), 10),
+		FinalityBranch:  branchToJSON(finalityBranch),
+		SyncAggregate:   SyncAggregateFromConsensus(update.SyncAggregate()),
+		SignatureSlot:   fmt.Sprintf("%d", update.SignatureSlot()),
 	}, nil
 }
 
-func LightClientOptimisticUpdateFromConsensus(update *v2.LightClientOptimisticUpdate) (*LightClientOptimisticUpdate, error) {
-	attestedHeader, err := lightClientHeaderContainerToJSON(update.AttestedHeader)
+func LightClientOptimisticUpdateFromConsensus(update interfaces.LightClientOptimisticUpdate) (*LightClientOptimisticUpdate, error) {
+	attestedHeader, err := lightClientHeaderToJSON(update.AttestedHeader())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not marshal attested light client header")
 	}
 
 	return &LightClientOptimisticUpdate{
 		AttestedHeader: attestedHeader,
-		SyncAggregate:  syncAggregateToJSON(update.SyncAggregate),
-		SignatureSlot:  strconv.FormatUint(uint64(update.SignatureSlot), 10),
+		SyncAggregate:  SyncAggregateFromConsensus(update.SyncAggregate()),
+		SignatureSlot:  fmt.Sprintf("%d", update.SignatureSlot()),
 	}, nil
 }
 
-func branchToJSON(branchBytes [][]byte) []string {
+func branchToJSON[S [][32]byte](branchBytes S) []string {
 	if branchBytes == nil {
 		return nil
 	}
 	branch := make([]string, len(branchBytes))
 	for i, root := range branchBytes {
-		branch[i] = hexutil.Encode(root)
+		branch[i] = hexutil.Encode(root[:])
 	}
 	return branch
 }
 
-func syncAggregateToJSON(input *v1.SyncAggregate) *SyncAggregate {
-	return &SyncAggregate{
-		SyncCommitteeBits:      hexutil.Encode(input.SyncCommitteeBits),
-		SyncCommitteeSignature: hexutil.Encode(input.SyncCommitteeSignature),
-	}
-}
-
-func lightClientHeaderContainerToJSON(container *v2.LightClientHeaderContainer) (json.RawMessage, error) {
+func lightClientHeaderToJSON(header interfaces.LightClientHeader) (json.RawMessage, error) {
 	// In the case that a finalizedHeader is nil.
-	if container == nil {
+	if header == nil {
 		return nil, nil
 	}
 
-	beacon, err := container.GetBeacon()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get beacon block header")
-	}
+	var result any
 
-	var header any
-
-	switch t := (container.Header).(type) {
-	case *v2.LightClientHeaderContainer_HeaderAltair:
-		header = &LightClientHeader{Beacon: BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(beacon))}
-	case *v2.LightClientHeaderContainer_HeaderCapella:
-		execution, err := ExecutionPayloadHeaderCapellaFromConsensus(t.HeaderCapella.Execution)
+	switch v := header.Version(); v {
+	case version.Altair:
+		result = &LightClientHeader{Beacon: BeaconBlockHeaderFromConsensus(header.Beacon())}
+	case version.Capella:
+		exInterface, err := header.Execution()
 		if err != nil {
 			return nil, err
 		}
-		header = &LightClientHeaderCapella{
-			Beacon:          BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(beacon)),
-			Execution:       execution,
-			ExecutionBranch: branchToJSON(t.HeaderCapella.ExecutionBranch),
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderCapella)
+		if !ok {
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderCapella{})
 		}
-	case *v2.LightClientHeaderContainer_HeaderDeneb:
-		execution, err := ExecutionPayloadHeaderDenebFromConsensus(t.HeaderDeneb.Execution)
+		execution, err := ExecutionPayloadHeaderCapellaFromConsensus(ex)
 		if err != nil {
 			return nil, err
 		}
-		header = &LightClientHeaderDeneb{
-			Beacon:          BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(beacon)),
+		executionBranch, err := header.ExecutionBranch()
+		if err != nil {
+			return nil, err
+		}
+		result = &LightClientHeaderCapella{
+			Beacon:          BeaconBlockHeaderFromConsensus(header.Beacon()),
 			Execution:       execution,
-			ExecutionBranch: branchToJSON(t.HeaderDeneb.ExecutionBranch),
+			ExecutionBranch: branchToJSON(executionBranch[:]),
+		}
+	case version.Deneb:
+		exInterface, err := header.Execution()
+		if err != nil {
+			return nil, err
+		}
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+		if !ok {
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderDeneb{})
+		}
+		execution, err := ExecutionPayloadHeaderDenebFromConsensus(ex)
+		if err != nil {
+			return nil, err
+		}
+		executionBranch, err := header.ExecutionBranch()
+		if err != nil {
+			return nil, err
+		}
+		result = &LightClientHeaderDeneb{
+			Beacon:          BeaconBlockHeaderFromConsensus(header.Beacon()),
+			Execution:       execution,
+			ExecutionBranch: branchToJSON(executionBranch[:]),
+		}
+	case version.Electra:
+		exInterface, err := header.Execution()
+		if err != nil {
+			return nil, err
+		}
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+		if !ok {
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderDeneb{})
+		}
+		execution, err := ExecutionPayloadHeaderElectraFromConsensus(ex)
+		if err != nil {
+			return nil, err
+		}
+		executionBranch, err := header.ExecutionBranch()
+		if err != nil {
+			return nil, err
+		}
+		result = &LightClientHeaderDeneb{
+			Beacon:          BeaconBlockHeaderFromConsensus(header.Beacon()),
+			Execution:       execution,
+			ExecutionBranch: branchToJSON(executionBranch[:]),
 		}
 	default:
-		return nil, fmt.Errorf("unsupported header type %T", t)
+		return nil, fmt.Errorf("unsupported header version %s", version.String(v))
 	}
 
-	return json.Marshal(header)
+	return json.Marshal(result)
+}
+
+func LightClientBootstrapFromConsensus(bootstrap interfaces.LightClientBootstrap) (*LightClientBootstrap, error) {
+	header, err := lightClientHeaderToJSON(bootstrap.Header())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal light client header")
+	}
+
+	var scBranch [][32]byte
+	if bootstrap.Version() >= version.Electra {
+		b, err := bootstrap.CurrentSyncCommitteeBranchElectra()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = b[:]
+	} else {
+		b, err := bootstrap.CurrentSyncCommitteeBranch()
+		if err != nil {
+			return nil, err
+		}
+		scBranch = b[:]
+	}
+
+	return &LightClientBootstrap{
+		Header:                     header,
+		CurrentSyncCommittee:       SyncCommitteeFromConsensus(bootstrap.CurrentSyncCommittee()),
+		CurrentSyncCommitteeBranch: branchToJSON(scBranch),
+	}, nil
 }

api/server/structs/conversions_state.go

@@ -11,6 +11,10 @@ import (
 
 var errPayloadHeaderNotFound = errors.New("expected payload header not found")
 
+// ----------------------------------------------------------------------------
+// Phase 0
+// ----------------------------------------------------------------------------
+
 func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -97,6 +101,10 @@ func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error)
 	}, nil
 }
 
+// ----------------------------------------------------------------------------
+// Altair
+// ----------------------------------------------------------------------------
+
 func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAltair, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -202,6 +210,10 @@ func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAlt
 	}, nil
 }
 
+// ----------------------------------------------------------------------------
+// Bellatrix
+// ----------------------------------------------------------------------------
+
 func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconStateBellatrix, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -320,6 +332,10 @@ func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconState
 	}, nil
 }
 
+// ----------------------------------------------------------------------------
+// Capella
+// ----------------------------------------------------------------------------
+
 func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCapella, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -457,6 +473,10 @@ func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCa
 	}, nil
 }
 
+// ----------------------------------------------------------------------------
+// Deneb
+// ----------------------------------------------------------------------------
+
 func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDeneb, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -594,6 +614,10 @@ func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDene
 	}, nil
 }
 
+// ----------------------------------------------------------------------------
+// Electra
+// ----------------------------------------------------------------------------
+
 func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateElectra, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -775,3 +799,189 @@ func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateEl
 		PendingConsolidations:         PendingConsolidationsFromConsensus(pc),
 	}, nil
 }
+
+// ----------------------------------------------------------------------------
+// Fulu
+// ----------------------------------------------------------------------------
+
+func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevPart, err := st.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	prevPart := make([]string, len(srcPrevPart))
+	for i, p := range srcPrevPart {
+		prevPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcCurrPart, err := st.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currPart := make([]string, len(srcCurrPart))
+	for i, p := range srcCurrPart {
+		currPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcIs, err := st.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	is := make([]string, len(srcIs))
+	for i, s := range srcIs {
+		is[i] = fmt.Sprintf("%d", s)
+	}
+	currSc, err := st.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSc, err := st.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	execData, err := st.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+	if !ok {
+		return nil, errPayloadHeaderNotFound
+	}
+	payload, err := ExecutionPayloadHeaderElectraFromConsensus(srcPayload)
+	if err != nil {
+		return nil, err
+	}
+	srcHs, err := st.HistoricalSummaries()
+	if err != nil {
+		return nil, err
+	}
+	hs := make([]*HistoricalSummary, len(srcHs))
+	for i, s := range srcHs {
+		hs[i] = HistoricalSummaryFromConsensus(s)
+	}
+	nwi, err := st.NextWithdrawalIndex()
+	if err != nil {
+		return nil, err
+	}
+	nwvi, err := st.NextWithdrawalValidatorIndex()
+	if err != nil {
+		return nil, err
+	}
+	drsi, err := st.DepositRequestsStartIndex()
+	if err != nil {
+		return nil, err
+	}
+	dbtc, err := st.DepositBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	ebtc, err := st.ExitBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	eee, err := st.EarliestExitEpoch()
+	if err != nil {
+		return nil, err
+	}
+	cbtc, err := st.ConsolidationBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	ece, err := st.EarliestConsolidationEpoch()
+	if err != nil {
+		return nil, err
+	}
+	pbd, err := st.PendingDeposits()
+	if err != nil {
+		return nil, err
+	}
+	ppw, err := st.PendingPartialWithdrawals()
+	if err != nil {
+		return nil, err
+	}
+	pc, err := st.PendingConsolidations()
+	if err != nil {
+		return nil, err
+	}
+
+	return &BeaconStateFulu{
+		GenesisTime:                   fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:         hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                          fmt.Sprintf("%d", st.Slot()),
+		Fork:                          ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:             BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                    br,
+		StateRoots:                    sr,
+		HistoricalRoots:               hr,
+		Eth1Data:                      Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:                 votes,
+		Eth1DepositIndex:              fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                    vals,
+		Balances:                      bals,
+		RandaoMixes:                   rm,
+		Slashings:                     slashings,
+		PreviousEpochParticipation:    prevPart,
+		CurrentEpochParticipation:     currPart,
+		JustificationBits:             hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint:   CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:    CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:           CheckpointFromConsensus(st.FinalizedCheckpoint()),
+		InactivityScores:              is,
+		CurrentSyncCommittee:          SyncCommitteeFromConsensus(currSc),
+		NextSyncCommittee:             SyncCommitteeFromConsensus(nextSc),
+		LatestExecutionPayloadHeader:  payload,
+		NextWithdrawalIndex:           fmt.Sprintf("%d", nwi),
+		NextWithdrawalValidatorIndex:  fmt.Sprintf("%d", nwvi),
+		HistoricalSummaries:           hs,
+		DepositRequestsStartIndex:     fmt.Sprintf("%d", drsi),
+		DepositBalanceToConsume:       fmt.Sprintf("%d", dbtc),
+		ExitBalanceToConsume:          fmt.Sprintf("%d", ebtc),
+		EarliestExitEpoch:             fmt.Sprintf("%d", eee),
+		ConsolidationBalanceToConsume: fmt.Sprintf("%d", cbtc),
+		EarliestConsolidationEpoch:    fmt.Sprintf("%d", ece),
+		PendingDeposits:               PendingDepositsFromConsensus(pbd),
+		PendingPartialWithdrawals:     PendingPartialWithdrawalsFromConsensus(ppw),
+		PendingConsolidations:         PendingConsolidationsFromConsensus(pc),
+	}, nil
+}

api/server/structs/conversions_test.go

@@ -24,3 +24,96 @@ func TestDepositSnapshotFromConsensus(t *testing.T) {
 	require.Equal(t, "0x1234", res.ExecutionBlockHash)
 	require.Equal(t, "67890", res.ExecutionBlockHeight)
 }
+
+func TestSignedBLSToExecutionChange_ToConsensus(t *testing.T) {
+	s := &SignedBLSToExecutionChange{Message: nil, Signature: ""}
+	_, err := s.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestSignedValidatorRegistration_ToConsensus(t *testing.T) {
+	s := &SignedValidatorRegistration{Message: nil, Signature: ""}
+	_, err := s.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestSignedContributionAndProof_ToConsensus(t *testing.T) {
+	s := &SignedContributionAndProof{Message: nil, Signature: ""}
+	_, err := s.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestContributionAndProof_ToConsensus(t *testing.T) {
+	c := &ContributionAndProof{
+		Contribution:    nil,
+		AggregatorIndex: "invalid",
+		SelectionProof:  "",
+	}
+	_, err := c.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestSignedAggregateAttestationAndProof_ToConsensus(t *testing.T) {
+	s := &SignedAggregateAttestationAndProof{Message: nil, Signature: ""}
+	_, err := s.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestAggregateAttestationAndProof_ToConsensus(t *testing.T) {
+	a := &AggregateAttestationAndProof{
+		AggregatorIndex: "1",
+		Aggregate:       nil,
+		SelectionProof:  "",
+	}
+	_, err := a.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestAttestation_ToConsensus(t *testing.T) {
+	a := &Attestation{
+		AggregationBits: "0x10",
+		Data:            nil,
+		Signature:       "",
+	}
+	_, err := a.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestSingleAttestation_ToConsensus(t *testing.T) {
+	s := &SingleAttestation{
+		CommitteeIndex: "1",
+		AttesterIndex:  "1",
+		Data:           nil,
+		Signature:      "",
+	}
+	_, err := s.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestSignedVoluntaryExit_ToConsensus(t *testing.T) {
+	s := &SignedVoluntaryExit{Message: nil, Signature: ""}
+	_, err := s.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestProposerSlashing_ToConsensus(t *testing.T) {
+	p := &ProposerSlashing{SignedHeader1: nil, SignedHeader2: nil}
+	_, err := p.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestAttesterSlashing_ToConsensus(t *testing.T) {
+	a := &AttesterSlashing{Attestation1: nil, Attestation2: nil}
+	_, err := a.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}
+
+func TestIndexedAttestation_ToConsensus(t *testing.T) {
+	a := &IndexedAttestation{
+		AttestingIndices: []string{"1"},
+		Data:             nil,
+		Signature:        "invalid",
+	}
+	_, err := a.ToConsensus()
+	require.ErrorContains(t, errNilValue.Error(), err)
+}

api/server/structs/endpoints_beacon.go

@@ -78,8 +78,8 @@ type GetBlockHeaderResponse struct {
 }
 
 type GetValidatorsRequest struct {
-	Ids      []string `json:"ids"`
-	Statuses []string `json:"statuses"`
+	Ids      []string `json:"ids,omitempty"`
+	Statuses []string `json:"statuses,omitempty"`
 }
 
 type GetValidatorsResponse struct {
@@ -100,6 +100,12 @@ type GetValidatorBalancesResponse struct {
 	Data                []*ValidatorBalance `json:"data"`
 }
 
+type GetValidatorIdentitiesResponse struct {
+	ExecutionOptimistic bool                 `json:"execution_optimistic"`
+	Finalized           bool                 `json:"finalized"`
+	Data                []*ValidatorIdentity `json:"data"`
+}
+
 type ValidatorContainer struct {
 	Index     string     `json:"index"`
 	Balance   string     `json:"balance"`
@@ -112,6 +118,12 @@ type ValidatorBalance struct {
 	Balance string `json:"balance"`
 }
 
+type ValidatorIdentity struct {
+	Index           string `json:"index"`
+	Pubkey          string `json:"pubkey"`
+	ActivationEpoch string `json:"activation_epoch"`
+}
+
 type GetBlockResponse struct {
 	Data *SignedBlock `json:"data"`
 }
@@ -250,3 +262,17 @@ type ChainHead struct {
 	PreviousJustifiedBlockRoot string `json:"previous_justified_block_root"`
 	OptimisticStatus           bool   `json:"optimistic_status"`
 }
+
+type GetPendingDepositsResponse struct {
+	Version             string            `json:"version"`
+	ExecutionOptimistic bool              `json:"execution_optimistic"`
+	Finalized           bool              `json:"finalized"`
+	Data                []*PendingDeposit `json:"data"`
+}
+
+type GetPendingPartialWithdrawalsResponse struct {
+	Version             string                      `json:"version"`
+	ExecutionOptimistic bool                        `json:"execution_optimistic"`
+	Finalized           bool                        `json:"finalized"`
+	Data                []*PendingPartialWithdrawal `json:"data"`
+}

api/server/structs/endpoints_blob.go

@@ -1,7 +1,10 @@
 package structs
 
 type SidecarsResponse struct {
-	Data []*Sidecar `json:"data"`
+	Version             string     `json:"version"`
+	Data                []*Sidecar `json:"data"`
+	ExecutionOptimistic bool       `json:"execution_optimistic"`
+	Finalized           bool       `json:"finalized"`
 }
 
 type Sidecar struct {

api/server/structs/endpoints_debug.go

@@ -54,4 +54,5 @@ type ForkChoiceNodeExtraData struct {
 	Balance                  string `json:"balance"`
 	ExecutionOptimistic      bool   `json:"execution_optimistic"`
 	TimeStamp                string `json:"timestamp"`
+	Target                   string `json:"target"`
 }

api/server/structs/endpoints_events.go

@@ -20,6 +20,11 @@ type BlockEvent struct {
 	ExecutionOptimistic bool   `json:"execution_optimistic"`
 }
 
+type BlockGossipEvent struct {
+	Slot  string `json:"slot"`
+	Block string `json:"block"`
+}
+
 type AggregatedAttEventSource struct {
 	Aggregate *Attestation `json:"aggregate"`
 }

api/server/structs/other.go

@@ -36,6 +36,13 @@ type AttestationElectra struct {
 	CommitteeBits   string           `json:"committee_bits"`
 }
 
+type SingleAttestation struct {
+	CommitteeIndex string           `json:"committee_index"`
+	AttesterIndex  string           `json:"attester_index"`
+	Data           *AttestationData `json:"data"`
+	Signature      string           `json:"signature"`
+}
+
 type AttestationData struct {
 	Slot            string      `json:"slot"`
 	CommitteeIndex  string      `json:"index"`
@@ -237,26 +244,6 @@ type Withdrawal struct {
 	Amount           string `json:"amount"`
 }
 
-type DepositRequest struct {
-	Pubkey                string `json:"pubkey"`
-	WithdrawalCredentials string `json:"withdrawal_credentials"`
-	Amount                string `json:"amount"`
-	Signature             string `json:"signature"`
-	Index                 string `json:"index"`
-}
-
-type WithdrawalRequest struct {
-	SourceAddress   string `json:"source_address"`
-	ValidatorPubkey string `json:"validator_pubkey"`
-	Amount          string `json:"amount"`
-}
-
-type ConsolidationRequest struct {
-	SourceAddress string `json:"source_address"`
-	SourcePubkey  string `json:"source_pubkey"`
-	TargetPubkey  string `json:"target_pubkey"`
-}
-
 type PendingDeposit struct {
 	Pubkey                string `json:"pubkey"`
 	WithdrawalCredentials string `json:"withdrawal_credentials"`

api/server/structs/state.go

@@ -142,41 +142,81 @@ type BeaconStateDeneb struct {
 }
 
 type BeaconStateElectra struct {
-	GenesisTime                   string                         `json:"genesis_time"`
-	GenesisValidatorsRoot         string                         `json:"genesis_validators_root"`
-	Slot                          string                         `json:"slot"`
-	Fork                          *Fork                          `json:"fork"`
-	LatestBlockHeader             *BeaconBlockHeader             `json:"latest_block_header"`
-	BlockRoots                    []string                       `json:"block_roots"`
-	StateRoots                    []string                       `json:"state_roots"`
-	HistoricalRoots               []string                       `json:"historical_roots"`
-	Eth1Data                      *Eth1Data                      `json:"eth1_data"`
-	Eth1DataVotes                 []*Eth1Data                    `json:"eth1_data_votes"`
-	Eth1DepositIndex              string                         `json:"eth1_deposit_index"`
-	Validators                    []*Validator                   `json:"validators"`
-	Balances                      []string                       `json:"balances"`
-	RandaoMixes                   []string                       `json:"randao_mixes"`
-	Slashings                     []string                       `json:"slashings"`
-	PreviousEpochParticipation    []string                       `json:"previous_epoch_participation"`
-	CurrentEpochParticipation     []string                       `json:"current_epoch_participation"`
-	JustificationBits             string                         `json:"justification_bits"`
-	PreviousJustifiedCheckpoint   *Checkpoint                    `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint    *Checkpoint                    `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint           *Checkpoint                    `json:"finalized_checkpoint"`
-	InactivityScores              []string                       `json:"inactivity_scores"`
-	CurrentSyncCommittee          *SyncCommittee                 `json:"current_sync_committee"`
-	NextSyncCommittee             *SyncCommittee                 `json:"next_sync_committee"`
-	LatestExecutionPayloadHeader  *ExecutionPayloadHeaderElectra `json:"latest_execution_payload_header"`
-	NextWithdrawalIndex           string                         `json:"next_withdrawal_index"`
-	NextWithdrawalValidatorIndex  string                         `json:"next_withdrawal_validator_index"`
-	HistoricalSummaries           []*HistoricalSummary           `json:"historical_summaries"`
-	DepositRequestsStartIndex     string                         `json:"deposit_requests_start_index"`
-	DepositBalanceToConsume       string                         `json:"deposit_balance_to_consume"`
-	ExitBalanceToConsume          string                         `json:"exit_balance_to_consume"`
-	EarliestExitEpoch             string                         `json:"earliest_exit_epoch"`
-	ConsolidationBalanceToConsume string                         `json:"consolidation_balance_to_consume"`
-	EarliestConsolidationEpoch    string                         `json:"earliest_consolidation_epoch"`
-	PendingDeposits               []*PendingDeposit              `json:"pending_deposits"`
-	PendingPartialWithdrawals     []*PendingPartialWithdrawal    `json:"pending_partial_withdrawals"`
-	PendingConsolidations         []*PendingConsolidation        `json:"pending_consolidations"`
+	GenesisTime                   string                       `json:"genesis_time"`
+	GenesisValidatorsRoot         string                       `json:"genesis_validators_root"`
+	Slot                          string                       `json:"slot"`
+	Fork                          *Fork                        `json:"fork"`
+	LatestBlockHeader             *BeaconBlockHeader           `json:"latest_block_header"`
+	BlockRoots                    []string                     `json:"block_roots"`
+	StateRoots                    []string                     `json:"state_roots"`
+	HistoricalRoots               []string                     `json:"historical_roots"`
+	Eth1Data                      *Eth1Data                    `json:"eth1_data"`
+	Eth1DataVotes                 []*Eth1Data                  `json:"eth1_data_votes"`
+	Eth1DepositIndex              string                       `json:"eth1_deposit_index"`
+	Validators                    []*Validator                 `json:"validators"`
+	Balances                      []string                     `json:"balances"`
+	RandaoMixes                   []string                     `json:"randao_mixes"`
+	Slashings                     []string                     `json:"slashings"`
+	PreviousEpochParticipation    []string                     `json:"previous_epoch_participation"`
+	CurrentEpochParticipation     []string                     `json:"current_epoch_participation"`
+	JustificationBits             string                       `json:"justification_bits"`
+	PreviousJustifiedCheckpoint   *Checkpoint                  `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint    *Checkpoint                  `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint           *Checkpoint                  `json:"finalized_checkpoint"`
+	InactivityScores              []string                     `json:"inactivity_scores"`
+	CurrentSyncCommittee          *SyncCommittee               `json:"current_sync_committee"`
+	NextSyncCommittee             *SyncCommittee               `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader  *ExecutionPayloadHeaderDeneb `json:"latest_execution_payload_header"`
+	NextWithdrawalIndex           string                       `json:"next_withdrawal_index"`
+	NextWithdrawalValidatorIndex  string                       `json:"next_withdrawal_validator_index"`
+	HistoricalSummaries           []*HistoricalSummary         `json:"historical_summaries"`
+	DepositRequestsStartIndex     string                       `json:"deposit_requests_start_index"`
+	DepositBalanceToConsume       string                       `json:"deposit_balance_to_consume"`
+	ExitBalanceToConsume          string                       `json:"exit_balance_to_consume"`
+	EarliestExitEpoch             string                       `json:"earliest_exit_epoch"`
+	ConsolidationBalanceToConsume string                       `json:"consolidation_balance_to_consume"`
+	EarliestConsolidationEpoch    string                       `json:"earliest_consolidation_epoch"`
+	PendingDeposits               []*PendingDeposit            `json:"pending_deposits"`
+	PendingPartialWithdrawals     []*PendingPartialWithdrawal  `json:"pending_partial_withdrawals"`
+	PendingConsolidations         []*PendingConsolidation      `json:"pending_consolidations"`
+}
+
+type BeaconStateFulu struct {
+	GenesisTime                   string                       `json:"genesis_time"`
+	GenesisValidatorsRoot         string                       `json:"genesis_validators_root"`
+	Slot                          string                       `json:"slot"`
+	Fork                          *Fork                        `json:"fork"`
+	LatestBlockHeader             *BeaconBlockHeader           `json:"latest_block_header"`
+	BlockRoots                    []string                     `json:"block_roots"`
+	StateRoots                    []string                     `json:"state_roots"`
+	HistoricalRoots               []string                     `json:"historical_roots"`
+	Eth1Data                      *Eth1Data                    `json:"eth1_data"`
+	Eth1DataVotes                 []*Eth1Data                  `json:"eth1_data_votes"`
+	Eth1DepositIndex              string                       `json:"eth1_deposit_index"`
+	Validators                    []*Validator                 `json:"validators"`
+	Balances                      []string                     `json:"balances"`
+	RandaoMixes                   []string                     `json:"randao_mixes"`
+	Slashings                     []string                     `json:"slashings"`
+	PreviousEpochParticipation    []string                     `json:"previous_epoch_participation"`
+	CurrentEpochParticipation     []string                     `json:"current_epoch_participation"`
+	JustificationBits             string                       `json:"justification_bits"`
+	PreviousJustifiedCheckpoint   *Checkpoint                  `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint    *Checkpoint                  `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint           *Checkpoint                  `json:"finalized_checkpoint"`
+	InactivityScores              []string                     `json:"inactivity_scores"`
+	CurrentSyncCommittee          *SyncCommittee               `json:"current_sync_committee"`
+	NextSyncCommittee             *SyncCommittee               `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader  *ExecutionPayloadHeaderDeneb `json:"latest_execution_payload_header"`
+	NextWithdrawalIndex           string                       `json:"next_withdrawal_index"`
+	NextWithdrawalValidatorIndex  string                       `json:"next_withdrawal_validator_index"`
+	HistoricalSummaries           []*HistoricalSummary         `json:"historical_summaries"`
+	DepositRequestsStartIndex     string                       `json:"deposit_requests_start_index"`
+	DepositBalanceToConsume       string                       `json:"deposit_balance_to_consume"`
+	ExitBalanceToConsume          string                       `json:"exit_balance_to_consume"`
+	EarliestExitEpoch             string                       `json:"earliest_exit_epoch"`
+	ConsolidationBalanceToConsume string                       `json:"consolidation_balance_to_consume"`
+	EarliestConsolidationEpoch    string                       `json:"earliest_consolidation_epoch"`
+	PendingDeposits               []*PendingDeposit            `json:"pending_deposits"`
+	PendingPartialWithdrawals     []*PendingPartialWithdrawal  `json:"pending_partial_withdrawals"`
+	PendingConsolidations         []*PendingConsolidation      `json:"pending_consolidations"`
 }

async/event/subscription.go

@@ -154,7 +154,7 @@ retry:
 				continue retry
 			}
 			if sub == nil {
-				panic("event: ResubscribeFunc returned nil subscription and no error")
+				panic("event: ResubscribeFunc returned nil subscription and no error") // lint:nopanic -- This should never happen.
 			}
 			return sub
 		case <-s.unsub:

async/multilock.go

@@ -125,7 +125,7 @@ func getChan(key string) chan byte {
 
 // Return a new string with unique elements.
 func unique(arr []string) []string {
-	if arr == nil || len(arr) <= 1 {
+	if len(arr) <= 1 {
 		return arr
 	}
 

beacon-chain/blockchain/BUILD.bazel

@@ -26,6 +26,7 @@ go_library(
         "receive_blob.go",
         "receive_block.go",
         "service.go",
+        "setup_forchoice.go",
         "tracked_proposer.go",
         "weak_subjectivity_checks.go",
     ],
@@ -43,6 +44,7 @@ go_library(
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/electra:go_default_library",
         "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
@@ -84,7 +86,6 @@ go_library(
         "//monitoring/tracing/trace:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",
         "//runtime/version:go_default_library",
@@ -96,6 +97,7 @@ go_library(
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@org_golang_x_sync//errgroup:go_default_library",
     ],
@@ -126,6 +128,7 @@ go_test(
         "receive_block_test.go",
         "service_norace_test.go",
         "service_test.go",
+        "setup_forkchoice_test.go",
         "setup_test.go",
         "weak_subjectivity_checks_test.go",
     ],
@@ -141,6 +144,7 @@ go_test(
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/das:go_default_library",
@@ -153,6 +157,7 @@ go_test(
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/operations/attestations:go_default_library",
+        "//beacon-chain/operations/attestations/kv:go_default_library",
         "//beacon-chain/operations/blstoexec:go_default_library",
         "//beacon-chain/operations/slashings:go_default_library",
         "//beacon-chain/operations/voluntaryexits:go_default_library",
@@ -184,6 +189,7 @@ go_test(
         "@com_github_ethereum_go_ethereum//core/types:go_default_library",
         "@com_github_holiman_uint256//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",

beacon-chain/blockchain/blockchain_test.go

@@ -2,6 +2,7 @@ package blockchain
 
 import (
 	"io"
+	"os"
 	"testing"
 
 	"github.com/sirupsen/logrus"
@@ -11,5 +12,5 @@ func TestMain(m *testing.M) {
 	logrus.SetLevel(logrus.DebugLevel)
 	logrus.SetOutput(io.Discard)
 
-	m.Run()
+	os.Exit(m.Run())
 }

beacon-chain/blockchain/chain_info_forkchoice.go

@@ -3,10 +3,13 @@ package blockchain
 import (
 	"context"
 
+	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/forkchoice"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )
 
 // CachedHeadRoot returns the corresponding value from Forkchoice
@@ -100,3 +103,26 @@ func (s *Service) ParentRoot(root [32]byte) ([32]byte, error) {
 	defer s.cfg.ForkChoiceStore.RUnlock()
 	return s.cfg.ForkChoiceStore.ParentRoot(root)
 }
+
+// hashForGenesisBlock returns the right hash for the genesis block
+func (s *Service) hashForGenesisBlock(ctx context.Context, root [32]byte) ([]byte, error) {
+	genRoot, err := s.cfg.BeaconDB.GenesisBlockRoot(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get genesis block root")
+	}
+	if root != genRoot {
+		return nil, errNotGenesisRoot
+	}
+	st, err := s.cfg.BeaconDB.GenesisState(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get genesis state")
+	}
+	if st.Version() < version.Bellatrix {
+		return nil, nil
+	}
+	header, err := st.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get latest execution payload header")
+	}
+	return bytesutil.SafeCopyBytes(header.BlockHash()), nil
+}

beacon-chain/blockchain/chain_info_test.go

@@ -13,7 +13,6 @@ import (
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
@@ -39,7 +38,7 @@ func prepareForkchoiceState(
 	payloadHash [32]byte,
 	justified *ethpb.Checkpoint,
 	finalized *ethpb.Checkpoint,
-) (state.BeaconState, consensus_blocks.ROBlock, error) {
+) (state.BeaconState, blocks.ROBlock, error) {
 	blockHeader := &ethpb.BeaconBlockHeader{
 		ParentRoot: parentRoot[:],
 	}
@@ -61,7 +60,7 @@ func prepareForkchoiceState(
 	base.BlockRoots[0] = append(base.BlockRoots[0], blockRoot[:]...)
 	st, err := state_native.InitializeFromProtoBellatrix(base)
 	if err != nil {
-		return nil, consensus_blocks.ROBlock{}, err
+		return nil, blocks.ROBlock{}, err
 	}
 	blk := &ethpb.SignedBeaconBlockBellatrix{
 		Block: &ethpb.BeaconBlockBellatrix{
@@ -76,9 +75,9 @@ func prepareForkchoiceState(
 	}
 	signed, err := blocks.NewSignedBeaconBlock(blk)
 	if err != nil {
-		return nil, consensus_blocks.ROBlock{}, err
+		return nil, blocks.ROBlock{}, err
 	}
-	roblock, err := consensus_blocks.NewROBlockWithRoot(signed, blockRoot)
+	roblock, err := blocks.NewROBlockWithRoot(signed, blockRoot)
 	return st, roblock, err
 }
 
@@ -583,6 +582,7 @@ func TestService_IsOptimisticForRoot_StateSummaryRecovered(t *testing.T) {
 	br, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
 	util.SaveBlock(t, context.Background(), beaconDB, b)
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, [32]byte{}))
 	_, err = c.IsOptimisticForRoot(ctx, br)
 	assert.NoError(t, err)
 	summ, err := beaconDB.StateSummary(ctx, br)
@@ -613,3 +613,20 @@ func TestService_IsFinalized(t *testing.T) {
 	require.Equal(t, true, c.IsFinalized(ctx, br))
 	require.Equal(t, false, c.IsFinalized(ctx, [32]byte{'c'}))
 }
+
+func Test_hashForGenesisRoot(t *testing.T) {
+	beaconDB := testDB.SetupDB(t)
+	ctx := context.Background()
+	c := setupBeaconChain(t, beaconDB)
+	st, _ := util.DeterministicGenesisStateElectra(t, 10)
+	require.NoError(t, c.cfg.BeaconDB.SaveGenesisData(ctx, st))
+	root, err := beaconDB.GenesisBlockRoot(ctx)
+	require.NoError(t, err)
+	genRoot, err := c.hashForGenesisBlock(ctx, [32]byte{'a'})
+	require.ErrorIs(t, err, errNotGenesisRoot)
+	require.IsNil(t, genRoot)
+
+	genRoot, err = c.hashForGenesisBlock(ctx, root)
+	require.NoError(t, err)
+	require.Equal(t, [32]byte{}, [32]byte(genRoot))
+}

beacon-chain/blockchain/error.go

@@ -30,6 +30,10 @@ var (
 	ErrNotCheckpoint = errors.New("not a checkpoint in forkchoice")
 	// ErrNilHead is returned when no head is present in the blockchain service.
 	ErrNilHead = errors.New("nil head")
+	// errNotGenesisRoot is returned when the root is not the genesis block root.
+	errNotGenesisRoot = errors.New("root is not the genesis block root")
+	// errBlacklistedBlock is returned when a block is blacklisted as invalid.
+	errBlacklistedRoot = errors.New("block root is blacklisted")
 )
 
 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")

beacon-chain/blockchain/execution_engine.go

@@ -69,10 +69,21 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		SafeBlockHash:      justifiedHash[:],
 		FinalizedBlockHash: finalizedHash[:],
 	}
+	if len(fcs.HeadBlockHash) != 32 || [32]byte(fcs.HeadBlockHash) == [32]byte{} {
+		// check if we are sending FCU at genesis
+		hash, err := s.hashForGenesisBlock(ctx, arg.headRoot)
+		if errors.Is(err, errNotGenesisRoot) {
+			log.Error("Sending nil head block hash to execution engine")
+			return nil, nil
+		}
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get head block hash")
+		}
+		fcs.HeadBlockHash = hash
+	}
 	if arg.attributes == nil {
 		arg.attributes = payloadattribute.EmptyWithVersion(headBlk.Version())
 	}
-	go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), arg)
 	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, arg.attributes)
 	if err != nil {
 		switch {
@@ -159,6 +170,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		log.WithFields(logrus.Fields{
 			"blockRoot": fmt.Sprintf("%#x", bytesutil.Trunc(arg.headRoot[:])),
 			"headSlot":  headBlk.Slot(),
+			"nextSlot":  nextSlot,
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
 		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
@@ -166,40 +178,19 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
 			"slot":      headBlk.Slot(),
+			"nextSlot":  nextSlot,
 		}).Error("Received nil payload ID on VALID engine response")
 	}
 	return payloadID, nil
 }
 
-func firePayloadAttributesEvent(ctx context.Context, f event.SubscriberSender, cfg *fcuConfig) {
-	pidx, err := helpers.BeaconProposerIndex(ctx, cfg.headState)
-	if err != nil {
-		log.WithError(err).
-			WithField("head_root", cfg.headRoot[:]).
-			Error("Could not get proposer index for PayloadAttributes event")
-		return
-	}
-	evd := payloadattribute.EventData{
-		ProposerIndex:   pidx,
-		ProposalSlot:    cfg.headState.Slot(),
-		ParentBlockRoot: cfg.headRoot[:],
-		Attributer:      cfg.attributes,
-		HeadRoot:        cfg.headRoot,
-		HeadState:       cfg.headState,
-		HeadBlock:       cfg.headBlock,
-	}
-	if cfg.headBlock != nil && !cfg.headBlock.IsNil() {
-		headPayload, err := cfg.headBlock.Block().Body().Execution()
-		if err != nil {
-			log.WithError(err).Error("Could not get execution payload for head block")
-			return
-		}
-		evd.ParentBlockHash = headPayload.BlockHash()
-		evd.ParentBlockNumber = headPayload.BlockNumber()
-	}
+func firePayloadAttributesEvent(_ context.Context, f event.SubscriberSender, nextSlot primitives.Slot) {
+	// the fcu args have differing amounts of completeness based on the code path,
+	// and there is work we only want to do if a client is actually listening to the events beacon api endpoint.
+	// temporary solution: just fire a blank event and fill in the details in the api handler.
 	f.Send(&feed.Event{
 		Type: statefeed.PayloadAttributes,
-		Data: evd,
+		Data: payloadattribute.EventData{ProposalSlot: nextSlot},
 	})
 }
 
@@ -268,6 +259,9 @@ func (s *Service) notifyNewPayload(ctx context.Context, preStateVersion int,
 		if err != nil {
 			return false, errors.Wrap(err, "could not get execution requests")
 		}
+		if requests == nil {
+			return false, errors.New("nil execution requests")
+		}
 	}
 	lastValidHash, err = s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload, versionedHashes, parentRoot, requests)
 
@@ -362,15 +356,16 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 		return emptyAttri
 	}
 
-	var attr payloadattribute.Attributer
-	switch st.Version() {
-	case version.Deneb, version.Electra:
+	v := st.Version()
+
+	if v >= version.Deneb {
 		withdrawals, _, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
 			return emptyAttri
 		}
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV3{
+
+		attr, err := payloadattribute.New(&enginev1.PayloadAttributesV3{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
 			SuggestedFeeRecipient: val.FeeRecipient[:],
@@ -381,13 +376,18 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			log.WithError(err).Error("Could not get payload attribute")
 			return emptyAttri
 		}
-	case version.Capella:
+
+		return attr
+	}
+
+	if v >= version.Capella {
 		withdrawals, _, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
 			return emptyAttri
 		}
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV2{
+
+		attr, err := payloadattribute.New(&enginev1.PayloadAttributesV2{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
 			SuggestedFeeRecipient: val.FeeRecipient[:],
@@ -397,8 +397,12 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			log.WithError(err).Error("Could not get payload attribute")
 			return emptyAttri
 		}
-	case version.Bellatrix:
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributes{
+
+		return attr
+	}
+
+	if v >= version.Bellatrix {
+		attr, err := payloadattribute.New(&enginev1.PayloadAttributes{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
 			SuggestedFeeRecipient: val.FeeRecipient[:],
@@ -407,12 +411,12 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			log.WithError(err).Error("Could not get payload attribute")
 			return emptyAttri
 		}
-	default:
-		log.WithField("version", st.Version()).Error("Could not get payload attribute due to unknown state version")
-		return emptyAttri
+
+		return attr
 	}
 
-	return attr
+	log.WithField("version", version.String(st.Version())).Error("Could not get payload attribute due to unknown state version")
+	return emptyAttri
 }
 
 // removeInvalidBlockAndState removes the invalid block, blob and its corresponding state from the cache and DB.

beacon-chain/blockchain/execution_engine_test.go

@@ -84,7 +84,7 @@ func Test_NotifyForkchoiceUpdate_GetPayloadAttrErrorCanContinue(t *testing.T) {
 	service.cfg.PayloadIDCache.Set(1, [32]byte{}, [8]byte{})
 	got, err := service.notifyForkchoiceUpdate(ctx, arg)
 	require.NoError(t, err)
-	require.DeepEqual(t, got, pid) // We still get a payload ID even though the state is bad. This means it returns until the end.
+	require.IsNil(t, got)
 }
 
 func Test_NotifyForkchoiceUpdate(t *testing.T) {
@@ -113,6 +113,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(ctx, 2, bellatrixBlkRoot, altairBlkRoot, params.BeaconConfig().ZeroHash, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
+	badHash := [32]byte{'h'}
 
 	tests := []struct {
 		name             string
@@ -210,7 +211,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 			blk: func() interfaces.ReadOnlySignedBeaconBlock {
 				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockBellatrix{Block: &ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
-						ExecutionPayload: &v1.ExecutionPayload{},
+						ExecutionPayload: &v1.ExecutionPayload{BlockHash: badHash[:]},
 					},
 				}})
 				require.NoError(t, err)

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -102,10 +102,10 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 		log.WithError(err).Error("could not save head")
 	}
 
+	go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
+
 	// Only need to prune attestations from pool if the head has changed.
-	if err := s.pruneAttsFromPool(args.headBlock); err != nil {
-		log.WithError(err).Error("could not prune attestations from pool")
-	}
+	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)
 	return nil
 }
 

beacon-chain/blockchain/head.go

@@ -11,6 +11,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -404,13 +405,23 @@ func (s *Service) saveOrphanedOperations(ctx context.Context, orphanedRoot [32]b
 			if a.GetData().Slot+params.BeaconConfig().SlotsPerEpoch < s.CurrentSlot() {
 				continue
 			}
-			if helpers.IsAggregated(a) {
-				if err := s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+			if features.Get().EnableExperimentalAttestationPool {
+				if err = s.cfg.AttestationCache.Add(a); err != nil {
 					return err
 				}
 			} else {
-				if err := s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
-					return err
+				if orphanedBlk.Version() >= version.Electra {
+					if err = s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
+						return err
+					}
+				} else if a.IsAggregated() {
+					if err = s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+						return err
+					}
+				} else {
+					if err = s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
+						return err
+					}
 				}
 			}
 			saveOrphanedAttCount.Inc()

beacon-chain/blockchain/head_test.go

@@ -324,6 +324,72 @@ func TestSaveOrphanedAtts(t *testing.T) {
 	require.DeepEqual(t, wantAtts, atts)
 }
 
+func TestSaveOrphanedAttsElectra(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//  \-4
+	st, keys := util.DeterministicGenesisStateElectra(t, 64)
+	blkG, err := util.GenerateFullBlockElectra(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+
+	util.SaveBlock(t, ctx, service.cfg.BeaconDB, blkG)
+	rG, err := blkG.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk1, err := util.GenerateFullBlockElectra(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlockElectra(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlockElectra(st, keys, util.DefaultBlockGenConfig(), 4)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlockElectra()
+	blk4.Block.Slot = 4
+	blk4.Block.ParentRoot = rG[:]
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+
+	for _, blk := range []*ethpb.SignedBeaconBlockElectra{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		state, blkRoot, err := prepareForkchoiceState(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, ojc, ofc)
+		require.NoError(t, err)
+		require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
+		util.SaveBlock(t, ctx, beaconDB, blk)
+	}
+
+	require.NoError(t, service.saveOrphanedOperations(ctx, r3, r4))
+	require.Equal(t, 3, len(service.cfg.AttPool.BlockAttestations()))
+	wantAtts := []ethpb.Att{
+		blk3.Block.Body.Attestations[0],
+		blk2.Block.Body.Attestations[0],
+		blk1.Block.Body.Attestations[0],
+	}
+	atts := service.cfg.AttPool.BlockAttestations()
+	sort.Slice(atts, func(i, j int) bool {
+		return atts[i].GetData().Slot > atts[j].GetData().Slot
+	})
+	require.DeepEqual(t, wantAtts, atts)
+}
+
 func TestSaveOrphanedOps(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig()

beacon-chain/blockchain/kzg/BUILD.bazel

@@ -26,8 +26,7 @@ go_test(
     deps = [
         "//consensus-types/blocks:go_default_library",
         "//testing/require:go_default_library",
-        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "//testing/util:go_default_library",
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )

beacon-chain/blockchain/kzg/validation.go

@@ -20,16 +20,17 @@ func Verify(sidecars ...blocks.ROBlob) error {
 	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
 	proofs := make([]GoKZG.KZGProof, len(sidecars))
 	for i, sidecar := range sidecars {
-		blobs[i] = bytesToBlob(sidecar.Blob)
+		blobs[i] = *bytesToBlob(sidecar.Blob)
 		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
 		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
 	}
 	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
 }
 
-func bytesToBlob(blob []byte) (ret GoKZG.Blob) {
+func bytesToBlob(blob []byte) *GoKZG.Blob {
+	var ret GoKZG.Blob
 	copy(ret[:], blob)
-	return
+	return &ret
 }
 
 func bytesToCommitment(commitment []byte) (ret GoKZG.KZGCommitment) {

beacon-chain/blockchain/kzg/validation_test.go

@@ -1,57 +1,20 @@
 package kzg
 
 import (
-	"bytes"
-	"crypto/sha256"
-	"encoding/binary"
 	"testing"
 
-	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/sirupsen/logrus"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
 )
 
-func deterministicRandomness(seed int64) [32]byte {
-	// Converts an int64 to a byte slice
-	buf := new(bytes.Buffer)
-	err := binary.Write(buf, binary.BigEndian, seed)
-	if err != nil {
-		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
-		return [32]byte{}
-	}
-	bytes := buf.Bytes()
-
-	return sha256.Sum256(bytes)
-}
-
-// Returns a serialized random field element in big-endian
-func GetRandFieldElement(seed int64) [32]byte {
-	bytes := deterministicRandomness(seed)
-	var r fr.Element
-	r.SetBytes(bytes[:])
-
-	return GoKZG.SerializeScalar(r)
-}
-
-// Returns a random blob using the passed seed as entropy
-func GetRandBlob(seed int64) GoKZG.Blob {
-	var blob GoKZG.Blob
-	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
-	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
-		fieldElementBytes := GetRandFieldElement(seed + int64(i))
-		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
-	}
-	return blob
-}
-
 func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZGProof, error) {
-	commitment, err := kzgContext.BlobToKZGCommitment(blob, 0)
+	commitment, err := kzgContext.BlobToKZGCommitment(&blob, 0)
 	if err != nil {
 		return GoKZG.KZGCommitment{}, GoKZG.KZGProof{}, err
 	}
-	proof, err := kzgContext.ComputeBlobKZGProof(blob, commitment, 0)
+	proof, err := kzgContext.ComputeBlobKZGProof(&blob, commitment, 0)
 	if err != nil {
 		return GoKZG.KZGCommitment{}, GoKZG.KZGProof{}, err
 	}
@@ -68,13 +31,13 @@ func TestBytesToAny(t *testing.T) {
 	blob := GoKZG.Blob{0x01, 0x02}
 	commitment := GoKZG.KZGCommitment{0x01, 0x02}
 	proof := GoKZG.KZGProof{0x01, 0x02}
-	require.DeepEqual(t, blob, bytesToBlob(bytes))
+	require.DeepEqual(t, blob, *bytesToBlob(bytes))
 	require.DeepEqual(t, commitment, bytesToCommitment(bytes))
 	require.DeepEqual(t, proof, bytesToKZGProof(bytes))
 }
 
 func TestGenerateCommitmentAndProof(t *testing.T) {
-	blob := GetRandBlob(123)
+	blob := util.GetRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
 	expectedCommitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}

beacon-chain/blockchain/log.go

@@ -69,6 +69,22 @@ func logStateTransitionData(b interfaces.ReadOnlyBeaconBlock) error {
 			log = log.WithField("kzgCommitmentCount", len(kzgs))
 		}
 	}
+	if b.Version() >= version.Electra {
+		eReqs, err := b.Body().ExecutionRequests()
+		if err != nil {
+			log.WithError(err).Error("Failed to get execution requests")
+		} else {
+			if len(eReqs.Deposits) > 0 {
+				log = log.WithField("depositRequestCount", len(eReqs.Deposits))
+			}
+			if len(eReqs.Consolidations) > 0 {
+				log = log.WithField("consolidationRequestCount", len(eReqs.Consolidations))
+			}
+			if len(eReqs.Withdrawals) > 0 {
+				log = log.WithField("withdrawalRequestCount", len(eReqs.Withdrawals))
+			}
+		}
+	}
 	log.Info("Finished applying state transition")
 	return nil
 }

beacon-chain/blockchain/mock_test.go

@@ -3,6 +3,7 @@ package blockchain
 import (
 	"testing"
 
+	mock "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/testing"
 	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
@@ -18,6 +19,7 @@ func testServiceOptsWithDB(t *testing.T) []Option {
 		WithStateGen(stategen.New(beaconDB, fcs)),
 		WithForkChoiceStore(fcs),
 		WithClockSynchronizer(cs),
+		WithStateNotifier(&mock.MockStateNotifier{RecordEvents: true}),
 	}
 }
 

beacon-chain/blockchain/options.go

@@ -85,6 +85,14 @@ func WithTrackedValidatorsCache(c *cache.TrackedValidatorsCache) Option {
 	}
 }
 
+// WithAttestationCache for attestation lifecycle after chain inclusion.
+func WithAttestationCache(c *cache.AttestationCache) Option {
+	return func(s *Service) error {
+		s.cfg.AttestationCache = c
+		return nil
+	}
+}
+
 // WithAttestationPool for attestation lifecycle after chain inclusion.
 func WithAttestationPool(p attestations.Pool) Option {
 	return func(s *Service) error {
@@ -205,3 +213,10 @@ func WithSyncChecker(checker Checker) Option {
 		return nil
 	}
 }
+
+func WithSlasherEnabled(enabled bool) Option {
+	return func(s *Service) error {
+		s.slasherEnabled = enabled
+		return nil
+	}
+}

beacon-chain/blockchain/process_attestation.go

@@ -80,7 +80,7 @@ func (s *Service) OnAttestation(ctx context.Context, a ethpb.Att, disparity time
 	}
 
 	// Use the target state to verify attesting indices are valid.
-	committees, err := helpers.AttestationCommittees(ctx, baseState, a)
+	committees, err := helpers.AttestationCommitteesFromState(ctx, baseState, a)
 	if err != nil {
 		return err
 	}

beacon-chain/blockchain/process_attestation_helpers.go

@@ -18,6 +18,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )
 
+// The caller of this function must have a lock on forkchoice.
 func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) state.ReadOnlyBeaconState {
 	headEpoch := slots.ToEpoch(s.HeadSlot())
 	if c.Epoch < headEpoch {
@@ -27,13 +28,6 @@ func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) st
 		return nil
 	}
 	if c.Epoch == headEpoch {
-		targetSlot, err := s.cfg.ForkChoiceStore.Slot([32]byte(c.Root))
-		if err != nil {
-			return nil
-		}
-		if slots.ToEpoch(targetSlot)+1 < headEpoch {
-			return nil
-		}
 		st, err := s.HeadStateReadOnly(ctx)
 		if err != nil {
 			return nil
@@ -65,12 +59,13 @@ func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) st
 		return nil
 	}
 	if err := s.checkpointStateCache.AddCheckpointState(c, st); err != nil {
-		return nil
+		log.WithError(err).Error("Could not save checkpoint state to cache")
 	}
 	return st
 }
 
 // getAttPreState retrieves the att pre state by either from the cache or the DB.
+// The caller of this function must have a lock on forkchoice.
 func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error) {
 	// If the attestation is recent and canonical we can use the head state to compute the shuffling.
 	if st := s.getRecentPreState(ctx, c); st != nil {

beacon-chain/blockchain/process_block.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	coreTime "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
@@ -67,7 +68,11 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 	if s.inRegularSync() {
 		defer s.handleSecondFCUCall(cfg, fcuArgs)
 	}
-	defer s.sendLightClientFeeds(cfg)
+	if features.Get().EnableLightClient && slots.ToEpoch(s.CurrentSlot()) >= params.BeaconConfig().AltairForkEpoch {
+		defer s.processLightClientUpdates(cfg)
+		defer s.saveLightClientUpdate(cfg)
+		defer s.saveLightClientBootstrap(cfg)
+	}
 	defer s.sendStateFeedOnBlock(cfg)
 	defer reportProcessingTime(startTime)
 	defer reportAttestationInclusion(cfg.roblock.Block())
@@ -170,6 +175,9 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	var set *bls.SignatureBatch
 	boundaries := make(map[[32]byte]state.BeaconState)
 	for i, b := range blks {
+		if features.BlacklistedBlock(b.Root()) {
+			return errBlacklistedRoot
+		}
 		v, h, err := getStateVersionAndPayload(preState)
 		if err != nil {
 			return err
@@ -365,7 +373,7 @@ func (s *Service) handleEpochBoundary(ctx context.Context, slot primitives.Slot,
 func (s *Service) handleBlockAttestations(ctx context.Context, blk interfaces.ReadOnlyBeaconBlock, st state.BeaconState) error {
 	// Feed in block's attestations to fork choice store.
 	for _, a := range blk.Body().Attestations() {
-		committees, err := helpers.AttestationCommittees(ctx, st, a)
+		committees, err := helpers.AttestationCommitteesFromState(ctx, st, a)
 		if err != nil {
 			return err
 		}
@@ -376,7 +384,11 @@ func (s *Service) handleBlockAttestations(ctx context.Context, blk interfaces.Re
 		r := bytesutil.ToBytes32(a.GetData().BeaconBlockRoot)
 		if s.cfg.ForkChoiceStore.HasNode(r) {
 			s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indices, r, a.GetData().Target.Epoch)
-		} else if err := s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
+		} else if features.Get().EnableExperimentalAttestationPool {
+			if err = s.cfg.AttestationCache.Add(a); err != nil {
+				return err
+			}
+		} else if err = s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
 			return err
 		}
 	}
@@ -404,29 +416,106 @@ func (s *Service) savePostStateInfo(ctx context.Context, r [32]byte, b interface
 		return errors.Wrapf(err, "could not save block from slot %d", b.Block().Slot())
 	}
 	if err := s.cfg.StateGen.SaveState(ctx, r, st); err != nil {
-		log.Warnf("Rolling back insertion of block with root %#x", r)
-		if err := s.cfg.BeaconDB.DeleteBlock(ctx, r); err != nil {
-			log.WithError(err).Errorf("Could not delete block with block root %#x", r)
-		}
+		// Do not use parent context in the event it deadlined
+		ctx = trace.NewContext(context.Background(), span)
+		s.rollbackBlock(ctx, r)
 		return errors.Wrap(err, "could not save state")
 	}
 	return nil
 }
 
-// This removes the attestations in block `b` from the attestation mem pool.
-func (s *Service) pruneAttsFromPool(headBlock interfaces.ReadOnlySignedBeaconBlock) error {
-	atts := headBlock.Block().Body().Attestations()
-	for _, att := range atts {
-		if helpers.IsAggregated(att) {
-			if err := s.cfg.AttPool.DeleteAggregatedAttestation(att); err != nil {
-				return err
-			}
-		} else {
-			if err := s.cfg.AttPool.DeleteUnaggregatedAttestation(att); err != nil {
-				return err
-			}
+// pruneAttsFromPool removes these attestations from the attestation pool
+// which are covered by attestations from the received block.
+func (s *Service) pruneAttsFromPool(ctx context.Context, headState state.BeaconState, headBlock interfaces.ReadOnlySignedBeaconBlock) {
+	for _, att := range headBlock.Block().Body().Attestations() {
+		if err := s.pruneCoveredAttsFromPool(ctx, headState, att); err != nil {
+			log.WithError(err).Warn("Could not prune attestations covered by a received block's attestation")
 		}
 	}
+}
+
+func (s *Service) pruneCoveredAttsFromPool(ctx context.Context, headState state.BeaconState, att ethpb.Att) error {
+	switch {
+	case !att.IsAggregated():
+		return s.cfg.AttPool.DeleteUnaggregatedAttestation(att)
+	case att.Version() == version.Phase0:
+		if features.Get().EnableExperimentalAttestationPool {
+			return errors.Wrap(s.cfg.AttestationCache.DeleteCovered(att), "could not delete covered attestation")
+		}
+		return errors.Wrap(s.cfg.AttPool.DeleteAggregatedAttestation(att), "could not delete aggregated attestation")
+	default:
+		return s.pruneCoveredElectraAttsFromPool(ctx, headState, att)
+	}
+}
+
+// pruneCoveredElectraAttsFromPool handles removing aggregated Electra attestations from the pool after receiving a block.
+// Because in Electra block attestations can combine aggregates for multiple committees, comparing attestation bits
+// of a block attestation with attestations bits of an aggregate can cause unexpected results, leading to covered
+// aggregates not being removed from the pool.
+//
+// To make sure aggregates are removed, we decompose the block attestation into dummy aggregates, with each
+// aggregate accounting for one committee. This allows us to compare aggregates in the same way it's done for
+// Phase0. Even though we can't provide a valid signature for the dummy aggregate, it does not matter because
+// signatures play no part in pruning attestations.
+func (s *Service) pruneCoveredElectraAttsFromPool(ctx context.Context, headState state.BeaconState, att ethpb.Att) error {
+	if att.Version() == version.Phase0 {
+		log.Error("Called pruneCoveredElectraAttsFromPool with a Phase0 attestation")
+		return nil
+	}
+
+	// We don't want to recompute committees. If they are not cached already,
+	// we allow attestations to stay in the pool. If these attestations are
+	// included in a later block, they will be redundant. But given that
+	// they were not cached in the first place, it's unlikely that they
+	// will be chosen into a block.
+	ok, committees, err := helpers.AttestationCommitteesFromCache(ctx, headState, att)
+	if err != nil {
+		return errors.Wrap(err, "could not get attestation committees")
+	}
+	if !ok {
+		log.Debug("Attestation committees are not cached. Skipping attestation pruning.")
+		return nil
+	}
+
+	committeeIndices := att.CommitteeBitsVal().BitIndices()
+	offset := uint64(0)
+
+	// Sanity check as this should never happen
+	if len(committeeIndices) != len(committees) {
+		return errors.New("committee indices and committees have different lengths")
+	}
+
+	for i, c := range committees {
+		ab := bitfield.NewBitlist(uint64(len(c)))
+		for j := uint64(0); j < uint64(len(c)); j++ {
+			ab.SetBitAt(j, att.GetAggregationBits().BitAt(j+offset))
+		}
+
+		cb := primitives.NewAttestationCommitteeBits()
+		cb.SetBitAt(uint64(committeeIndices[i]), true)
+
+		a := &ethpb.AttestationElectra{
+			AggregationBits: ab,
+			Data:            att.GetData(),
+			CommitteeBits:   cb,
+			Signature:       make([]byte, fieldparams.BLSSignatureLength),
+		}
+
+		if features.Get().EnableExperimentalAttestationPool {
+			if err = s.cfg.AttestationCache.DeleteCovered(a); err != nil {
+				return errors.Wrap(err, "could not delete covered attestation")
+			}
+		} else if !a.IsAggregated() {
+			if err = s.cfg.AttPool.DeleteUnaggregatedAttestation(a); err != nil {
+				return errors.Wrap(err, "could not delete unaggregated attestation")
+			}
+		} else if err = s.cfg.AttPool.DeleteAggregatedAttestation(a); err != nil {
+			return errors.Wrap(err, "could not delete aggregated attestation")
+		}
+
+		offset += uint64(len(c))
+	}
+
 	return nil
 }
 
@@ -494,24 +583,19 @@ func (s *Service) runLateBlockTasks() {
 // It returns a map where each key represents a missing BlobSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // BlobSidecars against the set of known missing sidecars.
-func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte) (map[uint64]struct{}, error) {
+func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte, slot primitives.Slot) (map[uint64]struct{}, error) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	if len(expected) == 0 {
 		return nil, nil
 	}
-	if len(expected) > fieldparams.MaxBlobsPerBlock {
+	if len(expected) > maxBlobsPerBlock {
 		return nil, errMaxBlobsExceeded
 	}
-	indices, err := bs.Indices(root)
-	if err != nil {
-		return nil, err
-	}
+	indices := bs.Summary(root)
 	missing := make(map[uint64]struct{}, len(expected))
 	for i := range expected {
-		ui := uint64(i)
-		if len(expected[i]) > 0 {
-			if !indices[i] {
-				missing[ui] = struct{}{}
-			}
+		if len(expected[i]) > 0 && !indices.HasIndex(uint64(i)) {
+			missing[uint64(i)] = struct{}{}
 		}
 	}
 	return missing, nil
@@ -550,7 +634,7 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 		return nil
 	}
 	// get a map of BlobSidecar indices that are not currently available.
-	missing, err := missingIndices(s.blobStorage, root, kzgCommitments)
+	missing, err := missingIndices(s.blobStorage, root, kzgCommitments, block.Slot())
 	if err != nil {
 		return err
 	}
@@ -561,7 +645,7 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 
 	// The gossip handler for blobs writes the index of each verified blob referencing the given
 	// root to the channel returned by blobNotifiers.forRoot.
-	nc := s.blobNotifiers.forRoot(root)
+	nc := s.blobNotifiers.forRoot(root, block.Slot())
 
 	// Log for DA checks that cross over into the next slot; helpful for debugging.
 	nextSlot := slots.BeginsAt(signed.Block().Slot()+1, s.genesisTime)
@@ -645,13 +729,9 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
 	// return early if we are not proposing next slot
 	if attribute.IsEmpty() {
-		fcuArgs := &fcuConfig{
-			headState:  headState,
-			headRoot:   headRoot,
-			headBlock:  nil,
-			attributes: attribute,
-		}
-		go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), fcuArgs)
+		// notifyForkchoiceUpdate fires the payload attribute event. But in this case, we won't
+		// call notifyForkchoiceUpdate, so the event is fired here.
+		go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
 		return
 	}
 

beacon-chain/blockchain/process_block_helpers.go

@@ -1,10 +1,13 @@
 package blockchain
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"strings"
 	"time"
 
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	lightclient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -15,7 +18,6 @@ import (
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
 	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -24,7 +26,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	mathutil "github.com/prysmaticlabs/prysm/v5/math"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
@@ -115,76 +116,147 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 	})
 }
 
-// sendLightClientFeeds sends the light client feeds when feature flag is enabled.
-func (s *Service) sendLightClientFeeds(cfg *postBlockProcessConfig) {
-	if features.Get().EnableLightClient {
-		if _, err := s.sendLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
-			log.WithError(err).Error("Failed to send light client optimistic update")
-		}
-
-		// Get the finalized checkpoint
-		finalized := s.ForkChoicer().FinalizedCheckpoint()
-
-		// LightClientFinalityUpdate needs super majority
-		s.tryPublishLightClientFinalityUpdate(cfg.ctx, cfg.roblock, finalized, cfg.postState)
+func (s *Service) processLightClientUpdates(cfg *postBlockProcessConfig) {
+	if err := s.processLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
+		log.WithError(err).Error("Failed to process light client optimistic update")
+	}
+	if err := s.processLightClientFinalityUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
+		log.WithError(err).Error("Failed to process light client finality update")
 	}
 }
 
-func (s *Service) tryPublishLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock, finalized *forkchoicetypes.Checkpoint, postState state.BeaconState) {
-	if finalized.Epoch <= s.lastPublishedLightClientEpoch {
-		return
-	}
-
-	config := params.BeaconConfig()
-	if finalized.Epoch < config.AltairForkEpoch {
-		return
-	}
-
-	syncAggregate, err := signed.Block().Body().SyncAggregate()
-	if err != nil || syncAggregate == nil {
-		return
-	}
-
-	// LightClientFinalityUpdate needs super majority
-	if syncAggregate.SyncCommitteeBits.Count()*3 < config.SyncCommitteeSize*2 {
-		return
-	}
-
-	_, err = s.sendLightClientFinalityUpdate(ctx, signed, postState)
+// saveLightClientUpdate saves the light client update for this block
+// if it's better than the already saved one, when feature flag is enabled.
+func (s *Service) saveLightClientUpdate(cfg *postBlockProcessConfig) {
+	attestedRoot := cfg.roblock.Block().ParentRoot()
+	attestedBlock, err := s.getBlock(cfg.ctx, attestedRoot)
 	if err != nil {
-		log.WithError(err).Error("Failed to send light client finality update")
+		log.WithError(err).Errorf("Saving light client update failed: Could not get attested block for root %#x", attestedRoot)
+		return
+	}
+	if attestedBlock == nil || attestedBlock.IsNil() {
+		log.Error("Saving light client update failed: Attested block is nil")
+		return
+	}
+	attestedState, err := s.cfg.StateGen.StateByRoot(cfg.ctx, attestedRoot)
+	if err != nil {
+		log.WithError(err).Errorf("Saving light client update failed: Could not get attested state for root %#x", attestedRoot)
+		return
+	}
+	if attestedState == nil || attestedState.IsNil() {
+		log.Error("Saving light client update failed: Attested state is nil")
+		return
+	}
+
+	finalizedRoot := attestedState.FinalizedCheckpoint().Root
+	finalizedBlock, err := s.getBlock(cfg.ctx, [32]byte(finalizedRoot))
+	if err != nil {
+		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
+			log.Debugf("Skipping saving light client update: Finalized block is nil for root %#x", finalizedRoot)
+		} else {
+			log.WithError(err).Errorf("Saving light client update failed: Could not get finalized block for root %#x", finalizedRoot)
+		}
+		return
+	}
+
+	update, err := lightclient.NewLightClientUpdateFromBeaconState(
+		cfg.ctx,
+		s.CurrentSlot(),
+		cfg.postState,
+		cfg.roblock,
+		attestedState,
+		attestedBlock,
+		finalizedBlock,
+	)
+	if err != nil {
+		log.WithError(err).Error("Saving light client update failed: Could not create light client update")
+		return
+	}
+
+	period := slots.SyncCommitteePeriod(slots.ToEpoch(attestedState.Slot()))
+
+	oldUpdate, err := s.cfg.BeaconDB.LightClientUpdate(cfg.ctx, period)
+	if err != nil {
+		log.WithError(err).Error("Saving light client update failed: Could not get current light client update")
+		return
+	}
+
+	if oldUpdate == nil {
+		if err := s.cfg.BeaconDB.SaveLightClientUpdate(cfg.ctx, period, update); err != nil {
+			log.WithError(err).Error("Saving light client update failed: Could not save light client update")
+		} else {
+			log.WithField("period", period).Debug("Saving light client update: Saved new update")
+		}
+		return
+	}
+
+	isNewUpdateBetter, err := lightclient.IsBetterUpdate(update, oldUpdate)
+	if err != nil {
+		log.WithError(err).Error("Saving light client update failed: Could not compare light client updates")
+		return
+	}
+
+	if isNewUpdateBetter {
+		if err := s.cfg.BeaconDB.SaveLightClientUpdate(cfg.ctx, period, update); err != nil {
+			log.WithError(err).Error("Saving light client update failed: Could not save light client update")
+		} else {
+			log.WithField("period", period).Debug("Saving light client update: Saved new update")
+		}
 	} else {
-		s.lastPublishedLightClientEpoch = finalized.Epoch
+		log.WithField("period", period).Debug("Saving light client update: New update is not better than the current one. Skipping save.")
 	}
 }
 
-// sendLightClientFinalityUpdate sends a light client finality update notification to the state feed.
-func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
-	postState state.BeaconState) (int, error) {
-	// Get attested state
+// saveLightClientBootstrap saves a light client bootstrap for this block
+// when feature flag is enabled.
+func (s *Service) saveLightClientBootstrap(cfg *postBlockProcessConfig) {
+	blockRoot := cfg.roblock.Root()
+	bootstrap, err := lightclient.NewLightClientBootstrapFromBeaconState(cfg.ctx, s.CurrentSlot(), cfg.postState, cfg.roblock)
+	if err != nil {
+		log.WithError(err).Error("Saving light client bootstrap failed: Could not create light client bootstrap")
+		return
+	}
+	err = s.cfg.BeaconDB.SaveLightClientBootstrap(cfg.ctx, blockRoot[:], bootstrap)
+	if err != nil {
+		log.WithError(err).Error("Saving light client bootstrap failed: Could not save light client bootstrap in DB")
+	}
+}
+
+func (s *Service) processLightClientFinalityUpdate(
+	ctx context.Context,
+	signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState,
+) error {
 	attestedRoot := signed.Block().ParentRoot()
 	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested block")
+		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested state")
+		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}
 
-	// Get finalized block
-	var finalizedBlock interfaces.ReadOnlySignedBeaconBlock
-	finalizedCheckPoint := attestedState.FinalizedCheckpoint()
-	if finalizedCheckPoint != nil {
-		finalizedRoot := bytesutil.ToBytes32(finalizedCheckPoint.Root)
-		finalizedBlock, err = s.cfg.BeaconDB.Block(ctx, finalizedRoot)
-		if err != nil {
-			finalizedBlock = nil
+	finalizedCheckpoint := attestedState.FinalizedCheckpoint()
+
+	// Check if the finalized checkpoint has changed
+	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+		return nil
+	}
+
+	finalizedRoot := bytesutil.ToBytes32(finalizedCheckpoint.Root)
+	finalizedBlock, err := s.cfg.BeaconDB.Block(ctx, finalizedRoot)
+	if err != nil {
+		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
+			log.Debugf("Skipping processing light client finality update: Finalized block is nil for root %#x", finalizedRoot)
+			return nil
 		}
+		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
 	}
 
 	update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
 		ctx,
+		postState.Slot(),
 		postState,
 		signed,
 		attestedState,
@@ -193,38 +265,31 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 	)
 
 	if err != nil {
-		return 0, errors.Wrap(err, "could not create light client update")
+		return errors.Wrap(err, "could not create light client finality update")
 	}
 
-	// Return the result
-	result := &ethpbv2.LightClientFinalityUpdateWithVersion{
-		Version: ethpbv2.Version(signed.Version()),
-		Data:    update,
-	}
-
-	// Send event
-	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.LightClientFinalityUpdate,
-		Data: result,
-	}), nil
+		Data: update,
+	})
+	return nil
 }
 
-// sendLightClientOptimisticUpdate sends a light client optimistic update notification to the state feed.
-func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
-	postState state.BeaconState) (int, error) {
-	// Get attested state
+func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState) error {
 	attestedRoot := signed.Block().ParentRoot()
 	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested block")
+		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested state")
+		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}
 
 	update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
 		ctx,
+		postState.Slot(),
 		postState,
 		signed,
 		attestedState,
@@ -232,19 +297,19 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 	)
 
 	if err != nil {
-		return 0, errors.Wrap(err, "could not create light client update")
+		if strings.Contains(err.Error(), lightclient.ErrNotEnoughSyncCommitteeBits) {
+			log.WithError(err).Debug("Skipping processing light client optimistic update")
+			return nil
+		}
+		return errors.Wrap(err, "could not create light client optimistic update")
 	}
 
-	// Return the result
-	result := &ethpbv2.LightClientOptimisticUpdateWithVersion{
-		Version: ethpbv2.Version(signed.Version()),
-		Data:    update,
-	}
-
-	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.LightClientOptimisticUpdate,
-		Data: result,
-	}), nil
+		Data: update,
+	})
+
+	return nil
 }
 
 // updateCachesPostBlockProcessing updates the next slot cache and handles the epoch
@@ -488,7 +553,8 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, signed inte
 
 // inserts finalized deposits into our finalized deposit trie, needs to be
 // called in the background
-func (s *Service) insertFinalizedDeposits(ctx context.Context, fRoot [32]byte) {
+// Post-Electra: prunes all proofs and pending deposits in the cache
+func (s *Service) insertFinalizedDepositsAndPrune(ctx context.Context, fRoot [32]byte) {
 	ctx, span := trace.StartSpan(ctx, "blockChain.insertFinalizedDeposits")
 	defer span.End()
 	startTime := time.Now()
@@ -499,6 +565,16 @@ func (s *Service) insertFinalizedDeposits(ctx context.Context, fRoot [32]byte) {
 		log.WithError(err).Error("could not fetch finalized state")
 		return
 	}
+
+	// Check if we should prune all pending deposits.
+	// In post-Electra(after the legacy deposit mechanism is deprecated),
+	// we can prune all pending deposits in the deposit cache.
+	// See: https://eips.ethereum.org/EIPS/eip-6110#eth1data-poll-deprecation
+	if helpers.DepositRequestsStarted(finalizedState) {
+		s.pruneAllPendingDepositsAndProofs(ctx)
+		return
+	}
+
 	// We update the cache up to the last deposit index in the finalized block's state.
 	// We can be confident that these deposits will be included in some block
 	// because the Eth1 follow distance makes such long-range reorgs extremely unlikely.
@@ -527,6 +603,12 @@ func (s *Service) insertFinalizedDeposits(ctx context.Context, fRoot [32]byte) {
 	log.WithField("duration", time.Since(startTime).String()).Debugf("Finalized deposit insertion completed at index %d", finalizedEth1DepIdx)
 }
 
+// pruneAllPendingDepositsAndProofs prunes all proofs and pending deposits in the cache.
+func (s *Service) pruneAllPendingDepositsAndProofs(ctx context.Context) {
+	s.cfg.DepositCache.PruneAllPendingDeposits(ctx)
+	s.cfg.DepositCache.PruneAllProofs(ctx)
+}
+
 // This ensures that the input root defaults to using genesis root instead of zero hashes. This is needed for handling
 // fork choice justification routine.
 func (s *Service) ensureRootNotZeros(root [32]byte) [32]byte {

beacon-chain/blockchain/process_block_test.go

@@ -12,8 +12,11 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	gethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	lightClient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
@@ -24,6 +27,7 @@ import (
 	mockExecution "github.com/prysmaticlabs/prysm/v5/beacon-chain/execution/testing"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations/kv"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
@@ -40,9 +44,98 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
 	prysmTime "github.com/prysmaticlabs/prysm/v5/time"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )
 
+func Test_pruneAttsFromPool_Electra(t *testing.T) {
+	ctx := context.Background()
+	logHook := logTest.NewGlobal()
+
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.TargetCommitteeSize = 8
+	params.OverrideBeaconConfig(cfg)
+
+	s := Service{
+		cfg: &config{
+			AttPool: kv.NewAttCaches(),
+		},
+	}
+
+	data := &ethpb.AttestationData{
+		BeaconBlockRoot: make([]byte, 32),
+		Source:          &ethpb.Checkpoint{Root: make([]byte, 32)},
+		Target:          &ethpb.Checkpoint{Root: make([]byte, 32)},
+	}
+
+	cb := primitives.NewAttestationCommitteeBits()
+	cb.SetBitAt(0, true)
+	att1 := &ethpb.AttestationElectra{
+		AggregationBits: bitfield.Bitlist{0b10000000, 0b00000001},
+		Data:            data,
+		Signature:       make([]byte, 96),
+		CommitteeBits:   cb,
+	}
+
+	cb = primitives.NewAttestationCommitteeBits()
+	cb.SetBitAt(1, true)
+	att2 := &ethpb.AttestationElectra{
+		AggregationBits: bitfield.Bitlist{0b11110111, 0b00000001},
+		Data:            data,
+		Signature:       make([]byte, 96),
+		CommitteeBits:   cb,
+	}
+
+	cb = primitives.NewAttestationCommitteeBits()
+	cb.SetBitAt(3, true)
+	att3 := &ethpb.AttestationElectra{
+		AggregationBits: bitfield.Bitlist{0b11110111, 0b00000001},
+		Data:            data,
+		Signature:       make([]byte, 96),
+		CommitteeBits:   cb,
+	}
+
+	require.NoError(t, s.cfg.AttPool.SaveUnaggregatedAttestation(att1))
+	require.NoError(t, s.cfg.AttPool.SaveAggregatedAttestation(att2))
+	require.NoError(t, s.cfg.AttPool.SaveAggregatedAttestation(att3))
+
+	cb = primitives.NewAttestationCommitteeBits()
+	cb.SetBitAt(0, true)
+	cb.SetBitAt(1, true)
+	onChainAtt := &ethpb.AttestationElectra{
+		AggregationBits: bitfield.Bitlist{0b10000000, 0b11110111, 0b00000001},
+		Data:            data,
+		Signature:       make([]byte, 96),
+		CommitteeBits:   cb,
+	}
+	bl := &ethpb.SignedBeaconBlockElectra{
+		Block: &ethpb.BeaconBlockElectra{
+			Body: &ethpb.BeaconBlockBodyElectra{
+				Attestations: []*ethpb.AttestationElectra{onChainAtt},
+			},
+		},
+		Signature: make([]byte, 96),
+	}
+	rob, err := consensusblocks.NewSignedBeaconBlock(bl)
+	require.NoError(t, err)
+	st, _ := util.DeterministicGenesisStateElectra(t, 1024)
+	committees, err := helpers.BeaconCommittees(ctx, st, 0)
+	require.NoError(t, err)
+	// Sanity check to make sure the on-chain att will be decomposed
+	// into the correct number of aggregates.
+	require.Equal(t, 4, len(committees))
+
+	s.pruneAttsFromPool(ctx, st, rob)
+	require.LogsDoNotContain(t, logHook, "Could not prune attestations")
+
+	attsInPool := s.cfg.AttPool.UnaggregatedAttestations()
+	assert.Equal(t, 0, len(attsInPool))
+	attsInPool = s.cfg.AttPool.AggregatedAttestations()
+	require.Equal(t, 1, len(attsInPool))
+	assert.DeepEqual(t, att3, attsInPool[0])
+}
+
 func TestStore_OnBlockBatch(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx := tr.ctx
@@ -721,7 +814,7 @@ func TestInsertFinalizedDeposits(t *testing.T) {
 			Signature:             zeroSig[:],
 		}, Proof: [][]byte{root}}, 100+i, int64(i), bytesutil.ToBytes32(root)))
 	}
-	service.insertFinalizedDeposits(ctx, [32]byte{'m', 'o', 'c', 'k'})
+	service.insertFinalizedDepositsAndPrune(ctx, [32]byte{'m', 'o', 'c', 'k'})
 	fDeposits, err := depositCache.FinalizedDeposits(ctx)
 	require.NoError(t, err)
 	assert.Equal(t, 7, int(fDeposits.MerkleTrieIndex()), "Finalized deposits not inserted correctly")
@@ -757,7 +850,7 @@ func TestInsertFinalizedDeposits_PrunePendingDeposits(t *testing.T) {
 			Signature:             zeroSig[:],
 		}, Proof: [][]byte{root}}, 100+i, int64(i), bytesutil.ToBytes32(root))
 	}
-	service.insertFinalizedDeposits(ctx, [32]byte{'m', 'o', 'c', 'k'})
+	service.insertFinalizedDepositsAndPrune(ctx, [32]byte{'m', 'o', 'c', 'k'})
 	fDeposits, err := depositCache.FinalizedDeposits(ctx)
 	require.NoError(t, err)
 	assert.Equal(t, 7, int(fDeposits.MerkleTrieIndex()), "Finalized deposits not inserted correctly")
@@ -797,7 +890,7 @@ func TestInsertFinalizedDeposits_MultipleFinalizedRoutines(t *testing.T) {
 	}
 	// Insert 3 deposits before hand.
 	require.NoError(t, depositCache.InsertFinalizedDeposits(ctx, 2, [32]byte{}, 0))
-	service.insertFinalizedDeposits(ctx, [32]byte{'m', 'o', 'c', 'k'})
+	service.insertFinalizedDepositsAndPrune(ctx, [32]byte{'m', 'o', 'c', 'k'})
 	fDeposits, err := depositCache.FinalizedDeposits(ctx)
 	require.NoError(t, err)
 	assert.Equal(t, 5, int(fDeposits.MerkleTrieIndex()), "Finalized deposits not inserted correctly")
@@ -808,7 +901,7 @@ func TestInsertFinalizedDeposits_MultipleFinalizedRoutines(t *testing.T) {
 	}
 
 	// Insert New Finalized State with higher deposit count.
-	service.insertFinalizedDeposits(ctx, [32]byte{'m', 'o', 'c', 'k', '2'})
+	service.insertFinalizedDepositsAndPrune(ctx, [32]byte{'m', 'o', 'c', 'k', '2'})
 	fDeposits, err = depositCache.FinalizedDeposits(ctx)
 	require.NoError(t, err)
 	assert.Equal(t, 12, int(fDeposits.MerkleTrieIndex()), "Finalized deposits not inserted correctly")
@@ -819,6 +912,8 @@ func TestInsertFinalizedDeposits_MultipleFinalizedRoutines(t *testing.T) {
 }
 
 func TestRemoveBlockAttestationsInPool(t *testing.T) {
+	logHook := logTest.NewGlobal()
+
 	genesis, keys := util.DeterministicGenesisState(t, 64)
 	b, err := util.GenerateFullBlock(genesis, keys, util.DefaultBlockGenConfig(), 1)
 	assert.NoError(t, err)
@@ -838,7 +933,8 @@ func TestRemoveBlockAttestationsInPool(t *testing.T) {
 	require.NoError(t, service.cfg.AttPool.SaveAggregatedAttestations(atts))
 	wsb, err := consensusblocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	require.NoError(t, service.pruneAttsFromPool(wsb))
+	service.pruneAttsFromPool(context.Background(), nil /* state not needed pre-Electra */, wsb)
+	require.LogsDoNotContain(t, logHook, "Could not prune attestations")
 	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
 }
 
@@ -1074,6 +1170,48 @@ func TestService_insertSlashingsToForkChoiceStore(t *testing.T) {
 	service.InsertSlashingsToForkChoiceStore(ctx, wb.Block().Body().AttesterSlashings())
 }
 
+func TestService_insertSlashingsToForkChoiceStoreElectra(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	beaconState, privKeys := util.DeterministicGenesisStateElectra(t, 100)
+	att1 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		Data: &ethpb.AttestationData{
+			Source: &ethpb.Checkpoint{Epoch: 1},
+		},
+		AttestingIndices: []uint64{0, 1},
+	})
+	domain, err := signing.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorsRoot())
+	require.NoError(t, err)
+	signingRoot, err := signing.ComputeSigningRoot(att1.Data, domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 := privKeys[0].Sign(signingRoot[:])
+	sig1 := privKeys[1].Sign(signingRoot[:])
+	aggregateSig := bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	att1.Signature = aggregateSig.Marshal()
+
+	att2 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		AttestingIndices: []uint64{0, 1},
+	})
+	signingRoot, err = signing.ComputeSigningRoot(att2.Data, domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = privKeys[0].Sign(signingRoot[:])
+	sig1 = privKeys[1].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	att2.Signature = aggregateSig.Marshal()
+	slashings := []*ethpb.AttesterSlashingElectra{
+		{
+			Attestation_1: att1,
+			Attestation_2: att2,
+		},
+	}
+	b := util.NewBeaconBlockElectra()
+	b.Block.Body.AttesterSlashings = slashings
+	wb, err := consensusblocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	service.InsertSlashingsToForkChoiceStore(ctx, wb.Block().Body().AttesterSlashings())
+}
+
 func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx := tr.ctx
@@ -1852,6 +1990,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, genesisState, genesisRoot), "Could not save genesis state")
 	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, genesisRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveGenesisBlockRoot(ctx, genesisRoot), "Could not save genesis state")
 
 	for i := 1; i < 6; i++ {
 		driftGenesisTime(service, int64(i), 0)
@@ -1986,6 +2125,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, genesisState, jroot))
 	service.cfg.ForkChoiceStore.SetBalancesByRooter(service.cfg.StateGen.ActiveNonSlashedBalancesByRoot)
 	require.NoError(t, service.StartFromSavedState(genesisState))
+	require.NoError(t, service.cfg.BeaconDB.SaveGenesisBlockRoot(ctx, genesisRoot))
 
 	// Forkchoice has the genesisRoot loaded at startup
 	require.Equal(t, genesisRoot, service.ensureRootNotZeros(service.cfg.ForkChoiceStore.CachedHeadRoot()))
@@ -2204,23 +2344,23 @@ func TestMissingIndices(t *testing.T) {
 		},
 		{
 			name:     "expected exceeds max",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock + 1),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0) + 1),
 			err:      errMaxBlobsExceeded,
 		},
 		{
 			name:     "first missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0)),
 			present:  []uint64{1, 2, 3, 4, 5},
 			result:   fakeResult([]uint64{0}),
 		},
 		{
 			name:     "all missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0)),
 			result:   fakeResult([]uint64{0, 1, 2, 3, 4, 5}),
 		},
 		{
 			name:     "none missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0)),
 			present:  []uint64{0, 1, 2, 3, 4, 5},
 			result:   fakeResult([]uint64{}),
 		},
@@ -2253,8 +2393,8 @@ func TestMissingIndices(t *testing.T) {
 	for _, c := range cases {
 		bm, bs := filesystem.NewEphemeralBlobStorageWithMocker(t)
 		t.Run(c.name, func(t *testing.T) {
-			require.NoError(t, bm.CreateFakeIndices(c.root, c.present...))
-			missing, err := missingIndices(bs, c.root, c.expected)
+			require.NoError(t, bm.CreateFakeIndices(c.root, 0, c.present...))
+			missing, err := missingIndices(bs, c.root, c.expected, 0)
 			if c.err != nil {
 				require.ErrorIs(t, err, c.err)
 				return
@@ -2352,6 +2492,62 @@ func TestRollbackBlock(t *testing.T) {
 	require.Equal(t, false, hasState)
 }
 
+func TestRollbackBlock_SavePostStateInfo_ContextDeadline(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	st, keys := util.DeterministicGenesisState(t, 64)
+	stateRoot, err := st.HashTreeRoot(ctx)
+	require.NoError(t, err, "Could not hash genesis state")
+
+	require.NoError(t, service.saveGenesisData(ctx, st))
+
+	genesis := blocks.NewGenesisBlock(stateRoot[:])
+	wsb, err := consensusblocks.NewSignedBeaconBlock(genesis)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb), "Could not save genesis block")
+	parentRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not get signing root")
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, st, parentRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, parentRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveJustifiedCheckpoint(ctx, &ethpb.Checkpoint{Root: parentRoot[:]}))
+	require.NoError(t, service.cfg.BeaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Root: parentRoot[:]}))
+
+	st, err = service.HeadState(ctx)
+	require.NoError(t, err)
+	b, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 128)
+	require.NoError(t, err)
+	wsb, err = consensusblocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	root, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	preState, err := service.getBlockPreState(ctx, wsb.Block())
+	require.NoError(t, err)
+	postState, err := service.validateStateTransition(ctx, preState, wsb)
+	require.NoError(t, err)
+
+	// Save state summaries so that the cache is flushed and saved to disk
+	// later.
+	for i := 1; i <= 127; i++ {
+		require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{
+			Slot: primitives.Slot(i),
+			Root: bytesutil.Bytes32(uint64(i)),
+		}))
+	}
+
+	// Set deadlined context when saving block and state
+	cancCtx, canc := context.WithCancel(ctx)
+	canc()
+
+	require.ErrorContains(t, context.Canceled.Error(), service.savePostStateInfo(cancCtx, root, wsb, postState))
+
+	// The block should no longer exist.
+	require.Equal(t, false, service.cfg.BeaconDB.HasBlock(ctx, root))
+	hasState, err := service.cfg.StateGen.HasState(ctx, root)
+	require.NoError(t, err)
+	require.Equal(t, false, hasState)
+}
+
 func TestRollbackBlock_ContextDeadline(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx := tr.ctx
@@ -2446,3 +2642,605 @@ func fakeResult(missing []uint64) map[uint64]struct{} {
 	}
 	return r
 }
+
+func TestSaveLightClientUpdate(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+
+	s, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	t.Run("Altair", func(t *testing.T) {
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			s.saveLightClientUpdate(cfg)
+
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Altair)
+		})
+
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Altair)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Altair)
+		})
+	})
+
+	t.Run("Capella", func(t *testing.T) {
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			s.saveLightClientUpdate(cfg)
+
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Capella)
+		})
+
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Capella)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Capella)
+		})
+	})
+
+	t.Run("Deneb", func(t *testing.T) {
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			s.saveLightClientUpdate(cfg)
+
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			require.NoError(t, err)
+			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+			require.NoError(t, err)
+
+			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+			require.NoError(t, err)
+			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+			require.NoError(t, err)
+			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+			require.NoError(t, err)
+
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+	})
+
+	reset()
+}
+
+func TestSaveLightClientBootstrap(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+
+	s, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	t.Run("Altair", func(t *testing.T) {
+		l := util.NewTestLightClient(t).SetupTestAltair()
+
+		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+		currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+		require.NoError(t, err)
+		roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+		require.NoError(t, err)
+
+		err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+		require.NoError(t, err)
+		err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+		require.NoError(t, err)
+
+		cfg := &postBlockProcessConfig{
+			ctx:            ctx,
+			roblock:        roblock,
+			postState:      l.State,
+			isValidPayload: true,
+		}
+
+		s.saveLightClientBootstrap(cfg)
+
+		// Check that the light client bootstrap is saved
+		b, err := s.cfg.BeaconDB.LightClientBootstrap(ctx, currentBlockRoot[:])
+		require.NoError(t, err)
+		require.NotNil(t, b)
+
+		stateRoot, err := l.State.HashTreeRoot(ctx)
+		require.NoError(t, err)
+		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
+		require.Equal(t, b.Version(), version.Altair)
+	})
+
+	t.Run("Capella", func(t *testing.T) {
+		l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+		currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+		require.NoError(t, err)
+		roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+		require.NoError(t, err)
+
+		err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+		require.NoError(t, err)
+		err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+		require.NoError(t, err)
+
+		cfg := &postBlockProcessConfig{
+			ctx:            ctx,
+			roblock:        roblock,
+			postState:      l.State,
+			isValidPayload: true,
+		}
+
+		s.saveLightClientBootstrap(cfg)
+
+		// Check that the light client bootstrap is saved
+		b, err := s.cfg.BeaconDB.LightClientBootstrap(ctx, currentBlockRoot[:])
+		require.NoError(t, err)
+		require.NotNil(t, b)
+
+		stateRoot, err := l.State.HashTreeRoot(ctx)
+		require.NoError(t, err)
+		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
+		require.Equal(t, b.Version(), version.Capella)
+	})
+
+	t.Run("Deneb", func(t *testing.T) {
+		l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+		currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+		require.NoError(t, err)
+		roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+		require.NoError(t, err)
+
+		err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+		require.NoError(t, err)
+		err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+		require.NoError(t, err)
+
+		cfg := &postBlockProcessConfig{
+			ctx:            ctx,
+			roblock:        roblock,
+			postState:      l.State,
+			isValidPayload: true,
+		}
+
+		s.saveLightClientBootstrap(cfg)
+
+		// Check that the light client bootstrap is saved
+		b, err := s.cfg.BeaconDB.LightClientBootstrap(ctx, currentBlockRoot[:])
+		require.NoError(t, err)
+		require.NotNil(t, b)
+
+		stateRoot, err := l.State.HashTreeRoot(ctx)
+		require.NoError(t, err)
+		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
+		require.Equal(t, b.Version(), version.Deneb)
+	})
+
+	reset()
+}

beacon-chain/blockchain/receive_attestation.go

@@ -9,6 +9,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -166,7 +167,13 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)
 
 // This processes fork choice attestations from the pool to account for validator votes and fork choice.
 func (s *Service) processAttestations(ctx context.Context, disparity time.Duration) {
-	atts := s.cfg.AttPool.ForkchoiceAttestations()
+	var atts []ethpb.Att
+	if features.Get().EnableExperimentalAttestationPool {
+		atts = s.cfg.AttestationCache.ForkchoiceAttestations()
+	} else {
+		atts = s.cfg.AttPool.ForkchoiceAttestations()
+	}
+
 	for _, a := range atts {
 		// Based on the spec, don't process the attestation until the subsequent slot.
 		// This delays consideration in the fork choice until their slot is in the past.
@@ -182,7 +189,11 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 			continue
 		}
 
-		if err := s.cfg.AttPool.DeleteForkchoiceAttestation(a); err != nil {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := s.cfg.AttestationCache.DeleteForkchoiceAttestation(a); err != nil {
+				log.WithError(err).Error("Could not delete fork choice attestation in pool")
+			}
+		} else if err := s.cfg.AttPool.DeleteForkchoiceAttestation(a); err != nil {
 			log.WithError(err).Error("Could not delete fork choice attestation in pool")
 		}
 

beacon-chain/blockchain/receive_attestation_test.go

@@ -10,7 +10,6 @@ import (
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -87,9 +86,7 @@ func TestProcessAttestations_Ok(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 	attsToSave := make([]ethpb.Att, len(atts))
-	for i, a := range atts {
-		attsToSave[i] = a
-	}
+	copy(attsToSave, atts)
 	require.NoError(t, service.cfg.AttPool.SaveForkchoiceAttestations(attsToSave))
 	service.processAttestations(ctx, 0)
 	require.Equal(t, 0, len(service.cfg.AttPool.ForkchoiceAttestations()))
@@ -119,7 +116,7 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, tRoot, wsb, postState))
-	roblock, err := consensus_blocks.NewROBlockWithRoot(wsb, tRoot)
+	roblock, err := blocks.NewROBlockWithRoot(wsb, tRoot)
 	require.NoError(t, err)
 	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, roblock, [32]byte{}, postState, false}))
 	copied, err = service.cfg.StateGen.StateByRoot(ctx, tRoot)
@@ -131,9 +128,7 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	atts, err := util.GenerateAttestations(copied, pks, 1, 1, false)
 	require.NoError(t, err)
 	attsToSave := make([]ethpb.Att, len(atts))
-	for i, a := range atts {
-		attsToSave[i] = a
-	}
+	copy(attsToSave, atts)
 	require.NoError(t, service.cfg.AttPool.SaveForkchoiceAttestations(attsToSave))
 	// Verify the target is in forkchoice
 	require.Equal(t, true, fcs.HasNode(bytesutil.ToBytes32(atts[0].GetData().BeaconBlockRoot)))
@@ -181,7 +176,7 @@ func TestService_UpdateHead_NoAtts(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, tRoot, wsb, postState))
-	roblock, err := consensus_blocks.NewROBlockWithRoot(wsb, tRoot)
+	roblock, err := blocks.NewROBlockWithRoot(wsb, tRoot)
 	require.NoError(t, err)
 	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, roblock, [32]byte{}, postState, false}))
 	require.Equal(t, 2, fcs.NodeCount())

beacon-chain/blockchain/receive_blob.go

@@ -4,12 +4,13 @@ import (
 	"context"
 
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )
 
 // SendNewBlobEvent sends a message to the BlobNotifier channel that the blob
 // for the block root `root` is ready in the database
-func (s *Service) sendNewBlobEvent(root [32]byte, index uint64) {
-	s.blobNotifiers.notifyIndex(root, index)
+func (s *Service) sendNewBlobEvent(root [32]byte, index uint64, slot primitives.Slot) {
+	s.blobNotifiers.notifyIndex(root, index, slot)
 }
 
 // ReceiveBlob saves the blob to database and sends the new event
@@ -18,6 +19,6 @@ func (s *Service) ReceiveBlob(ctx context.Context, b blocks.VerifiedROBlob) erro
 		return err
 	}
 
-	s.sendNewBlobEvent(b.BlockRoot(), b.Index)
+	s.sendNewBlobEvent(b.BlockRoot(), b.Index, b.Slot())
 	return nil
 }

beacon-chain/blockchain/receive_block.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/electra"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
@@ -17,8 +18,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -66,6 +65,10 @@ type SlashingReceiver interface {
 func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlock")
 	defer span.End()
+	// Return early if the block is blacklisted
+	if features.BlacklistedBlock(blockRoot) {
+		return errBlacklistedRoot
+	}
 	// Return early if the block has been synced
 	if s.InForkchoice(blockRoot) {
 		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring already synced block")
@@ -85,7 +88,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	}
 
 	currentCheckpoints := s.saveCurrentCheckpoints(preState)
-	roblock, err := consensus_blocks.NewROBlockWithRoot(blockCopy, blockRoot)
+	roblock, err := blocks.NewROBlockWithRoot(blockCopy, blockRoot)
 	if err != nil {
 		return err
 	}
@@ -122,7 +125,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		return err
 	}
 	// If slasher is configured, forward the attestations in the block via an event feed for processing.
-	if features.Get().EnableSlasher {
+	if s.slasherEnabled {
 		go s.sendBlockAttestationsToSlasher(blockCopy, preState)
 	}
 
@@ -190,7 +193,7 @@ func (s *Service) updateCheckpoints(
 func (s *Service) validateExecutionAndConsensus(
 	ctx context.Context,
 	preState state.BeaconState,
-	block consensusblocks.ROBlock,
+	block blocks.ROBlock,
 ) (state.BeaconState, bool, error) {
 	preStateVersion, preStateHeader, err := getStateVersionAndPayload(preState)
 	if err != nil {
@@ -280,9 +283,10 @@ func (s *Service) executePostFinalizationTasks(ctx context.Context, finalizedSta
 	go func() {
 		s.sendNewFinalizedEvent(ctx, finalizedState)
 	}()
+
 	depCtx, cancel := context.WithTimeout(context.Background(), depositDeadline)
 	go func() {
-		s.insertFinalizedDeposits(depCtx, finalized.Root)
+		s.insertFinalizedDepositsAndPrune(depCtx, finalized.Root)
 		cancel()
 	}()
 }
@@ -470,6 +474,9 @@ func (s *Service) validateStateTransition(ctx context.Context, preState state.Be
 	stateTransitionStartTime := time.Now()
 	postState, err := transition.ExecuteStateTransition(ctx, preState, signed)
 	if err != nil {
+		if ctx.Err() != nil || electra.IsExecutionRequestError(err) {
+			return nil, err
+		}
 		return nil, invalidBlock{error: err}
 	}
 	stateTransitionProcessingTime.Observe(float64(time.Since(stateTransitionStartTime).Milliseconds()))
@@ -545,7 +552,7 @@ func (s *Service) sendBlockAttestationsToSlasher(signed interfaces.ReadOnlySigne
 	// is done in the background to avoid adding more load to this critical code path.
 	ctx := context.TODO()
 	for _, att := range signed.Block().Body().Attestations() {
-		committees, err := helpers.AttestationCommittees(ctx, preState, att)
+		committees, err := helpers.AttestationCommitteesFromState(ctx, preState, att)
 		if err != nil {
 			log.WithError(err).Error("Could not get attestation committees")
 			return
@@ -560,7 +567,7 @@ func (s *Service) sendBlockAttestationsToSlasher(signed interfaces.ReadOnlySigne
 }
 
 // validateExecutionOnBlock notifies the engine of the incoming block execution payload and returns true if the payload is valid
-func (s *Service) validateExecutionOnBlock(ctx context.Context, ver int, header interfaces.ExecutionData, block consensusblocks.ROBlock) (bool, error) {
+func (s *Service) validateExecutionOnBlock(ctx context.Context, ver int, header interfaces.ExecutionData, block blocks.ROBlock) (bool, error) {
 	isValidPayload, err := s.notifyNewPayload(ctx, ver, header, block)
 	if err != nil {
 		s.cfg.ForkChoiceStore.Lock()

beacon-chain/blockchain/receive_block_test.go

@@ -12,6 +12,7 @@ import (
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/voluntaryexits"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -41,6 +42,16 @@ func TestService_ReceiveBlock(t *testing.T) {
 	bc.ShardCommitteePeriod = 0 // Required for voluntary exits test in reasonable time.
 	params.OverrideBeaconConfig(bc)
 
+	badBlock := genFullBlock(t, util.DefaultBlockGenConfig(), 101)
+	badRoot, err := badBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	badRoots := make(map[[32]byte]struct{})
+	badRoots[badRoot] = struct{}{}
+	resetCfg := features.InitWithReset(&features.Flags{
+		BlacklistedRoots: badRoots,
+	})
+	defer resetCfg()
+
 	type args struct {
 		block *ethpb.SignedBeaconBlock
 	}
@@ -124,8 +135,14 @@ func TestService_ReceiveBlock(t *testing.T) {
 				}
 			},
 		},
+		{
+			name: "The block is blacklisted",
+			args: args{
+				block: badBlock,
+			},
+			wantedErr: errBlacklistedRoot.Error(),
+		},
 	}
-
 	wg := new(sync.WaitGroup)
 	for _, tt := range tests {
 		wg.Add(1)
@@ -455,41 +472,81 @@ func Test_executePostFinalizationTasks(t *testing.T) {
 		Root:  headRoot[:],
 	}))
 	require.NoError(t, headState.SetGenesisValidatorsRoot(params.BeaconConfig().ZeroHash[:]))
+	t.Run("pre deposit request", func(t *testing.T) {
+		require.NoError(t, headState.SetEth1DepositIndex(1))
+		s, tr := minimalTestService(t, WithFinalizedStateAtStartUp(headState))
+		ctx, beaconDB, stateGen := tr.ctx, tr.db, tr.sg
 
-	s, tr := minimalTestService(t, WithFinalizedStateAtStartUp(headState))
-	ctx, beaconDB, stateGen := tr.ctx, tr.db, tr.sg
+		require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, genesisRoot))
+		util.SaveBlock(t, ctx, beaconDB, genesis)
+		require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
+		require.NoError(t, beaconDB.SaveState(ctx, headState, genesisRoot))
+		util.SaveBlock(t, ctx, beaconDB, headBlock)
+		require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
 
-	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, genesisRoot))
-	util.SaveBlock(t, ctx, beaconDB, genesis)
-	require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
-	require.NoError(t, beaconDB.SaveState(ctx, headState, genesisRoot))
-	util.SaveBlock(t, ctx, beaconDB, headBlock)
-	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
+		require.NoError(t, err)
+		require.NoError(t, stateGen.SaveState(ctx, headRoot, headState))
+		require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
 
-	require.NoError(t, err)
-	require.NoError(t, stateGen.SaveState(ctx, headRoot, headState))
-	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
+		notifier := &blockchainTesting.MockStateNotifier{RecordEvents: true}
+		s.cfg.StateNotifier = notifier
+		s.executePostFinalizationTasks(s.ctx, headState)
 
-	notifier := &blockchainTesting.MockStateNotifier{RecordEvents: true}
-	s.cfg.StateNotifier = notifier
-	s.executePostFinalizationTasks(s.ctx, headState)
+		time.Sleep(1 * time.Second) // sleep for a second because event is in a separate go routine
+		require.Equal(t, 1, len(notifier.ReceivedEvents()))
+		e := notifier.ReceivedEvents()[0]
+		assert.Equal(t, statefeed.FinalizedCheckpoint, int(e.Type))
+		fc, ok := e.Data.(*ethpbv1.EventFinalizedCheckpoint)
+		require.Equal(t, true, ok, "event has wrong data type")
+		assert.Equal(t, primitives.Epoch(123), fc.Epoch)
+		assert.DeepEqual(t, headRoot[:], fc.Block)
+		assert.DeepEqual(t, finalizedStRoot[:], fc.State)
+		assert.Equal(t, false, fc.ExecutionOptimistic)
 
-	time.Sleep(1 * time.Second) // sleep for a second because event is in a separate go routine
-	require.Equal(t, 1, len(notifier.ReceivedEvents()))
-	e := notifier.ReceivedEvents()[0]
-	assert.Equal(t, statefeed.FinalizedCheckpoint, int(e.Type))
-	fc, ok := e.Data.(*ethpbv1.EventFinalizedCheckpoint)
-	require.Equal(t, true, ok, "event has wrong data type")
-	assert.Equal(t, primitives.Epoch(123), fc.Epoch)
-	assert.DeepEqual(t, headRoot[:], fc.Block)
-	assert.DeepEqual(t, finalizedStRoot[:], fc.State)
-	assert.Equal(t, false, fc.ExecutionOptimistic)
+		// check the cache
+		index, ok := headState.ValidatorIndexByPubkey(bytesutil.ToBytes48(key))
+		require.Equal(t, true, ok)
+		require.Equal(t, primitives.ValidatorIndex(0), index) // first index
 
-	// check the cache
-	index, ok := headState.ValidatorIndexByPubkey(bytesutil.ToBytes48(key))
-	require.Equal(t, true, ok)
-	require.Equal(t, primitives.ValidatorIndex(0), index) // first index
+		// check deposit
+		require.LogsContain(t, logHook, "Finalized deposit insertion completed at index")
+	})
+	t.Run("deposit requests started", func(t *testing.T) {
+		require.NoError(t, headState.SetEth1DepositIndex(1))
+		require.NoError(t, headState.SetDepositRequestsStartIndex(1))
+		s, tr := minimalTestService(t, WithFinalizedStateAtStartUp(headState))
+		ctx, beaconDB, stateGen := tr.ctx, tr.db, tr.sg
+
+		require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, genesisRoot))
+		util.SaveBlock(t, ctx, beaconDB, genesis)
+		require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
+		require.NoError(t, beaconDB.SaveState(ctx, headState, genesisRoot))
+		util.SaveBlock(t, ctx, beaconDB, headBlock)
+		require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
+
+		require.NoError(t, err)
+		require.NoError(t, stateGen.SaveState(ctx, headRoot, headState))
+		require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
+
+		notifier := &blockchainTesting.MockStateNotifier{RecordEvents: true}
+		s.cfg.StateNotifier = notifier
+		s.executePostFinalizationTasks(s.ctx, headState)
+
+		time.Sleep(1 * time.Second) // sleep for a second because event is in a separate go routine
+		require.Equal(t, 1, len(notifier.ReceivedEvents()))
+		e := notifier.ReceivedEvents()[0]
+		assert.Equal(t, statefeed.FinalizedCheckpoint, int(e.Type))
+		fc, ok := e.Data.(*ethpbv1.EventFinalizedCheckpoint)
+		require.Equal(t, true, ok, "event has wrong data type")
+		assert.Equal(t, primitives.Epoch(123), fc.Epoch)
+		assert.DeepEqual(t, headRoot[:], fc.Block)
+		assert.DeepEqual(t, finalizedStRoot[:], fc.State)
+		assert.Equal(t, false, fc.ExecutionOptimistic)
+
+		// check the cache
+		index, ok := headState.ValidatorIndexByPubkey(bytesutil.ToBytes48(key))
+		require.Equal(t, true, ok)
+		require.Equal(t, primitives.ValidatorIndex(0), index) // first index
+	})
 
-	// check deposit
-	require.LogsContain(t, logHook, "Finalized deposit insertion completed at index")
 }

beacon-chain/blockchain/service.go

@@ -3,7 +3,6 @@
 package blockchain
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"runtime"
@@ -23,7 +22,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
 	f "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/blstoexec"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/slashings"
@@ -32,11 +30,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	consensus_blocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -44,30 +39,31 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	prysmTime "github.com/prysmaticlabs/prysm/v5/time"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/sirupsen/logrus"
 )
 
 // Service represents a service that handles the internal
 // logic of managing the full PoS beacon chain.
 type Service struct {
-	cfg                           *config
-	ctx                           context.Context
-	cancel                        context.CancelFunc
-	genesisTime                   time.Time
-	head                          *head
-	headLock                      sync.RWMutex
-	originBlockRoot               [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
-	boundaryRoots                 [][32]byte
-	checkpointStateCache          *cache.CheckpointStateCache
-	initSyncBlocks                map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
-	initSyncBlocksLock            sync.RWMutex
-	wsVerifier                    *WeakSubjectivityVerifier
-	clockSetter                   startup.ClockSetter
-	clockWaiter                   startup.ClockWaiter
-	syncComplete                  chan struct{}
-	blobNotifiers                 *blobNotifierMap
-	blockBeingSynced              *currentlySyncingBlock
-	blobStorage                   *filesystem.BlobStorage
-	lastPublishedLightClientEpoch primitives.Epoch
+	cfg                  *config
+	ctx                  context.Context
+	cancel               context.CancelFunc
+	genesisTime          time.Time
+	head                 *head
+	headLock             sync.RWMutex
+	originBlockRoot      [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
+	boundaryRoots        [][32]byte
+	checkpointStateCache *cache.CheckpointStateCache
+	initSyncBlocks       map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
+	initSyncBlocksLock   sync.RWMutex
+	wsVerifier           *WeakSubjectivityVerifier
+	clockSetter          startup.ClockSetter
+	clockWaiter          startup.ClockWaiter
+	syncComplete         chan struct{}
+	blobNotifiers        *blobNotifierMap
+	blockBeingSynced     *currentlySyncingBlock
+	blobStorage          *filesystem.BlobStorage
+	slasherEnabled       bool
 }
 
 // config options for the service.
@@ -78,6 +74,7 @@ type config struct {
 	DepositCache            cache.DepositCache
 	PayloadIDCache          *cache.PayloadIDCache
 	TrackedValidatorsCache  *cache.TrackedValidatorsCache
+	AttestationCache        *cache.AttestationCache
 	AttPool                 attestations.Pool
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
@@ -107,18 +104,22 @@ var ErrMissingClockSetter = errors.New("blockchain Service initialized without a
 type blobNotifierMap struct {
 	sync.RWMutex
 	notifiers map[[32]byte]chan uint64
-	seenIndex map[[32]byte][fieldparams.MaxBlobsPerBlock]bool
+	seenIndex map[[32]byte][]bool
 }
 
 // notifyIndex notifies a blob by its index for a given root.
 // It uses internal maps to keep track of seen indices and notifier channels.
-func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
-	if idx >= fieldparams.MaxBlobsPerBlock {
+func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitives.Slot) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	if idx >= uint64(maxBlobsPerBlock) {
 		return
 	}
 
 	bn.Lock()
 	seen := bn.seenIndex[root]
+	if seen == nil {
+		seen = make([]bool, maxBlobsPerBlock)
+	}
 	if seen[idx] {
 		bn.Unlock()
 		return
@@ -129,7 +130,7 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	// Retrieve or create the notifier channel for the given root.
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		c = make(chan uint64, maxBlobsPerBlock)
 		bn.notifiers[root] = c
 	}
 
@@ -138,12 +139,13 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	c <- idx
 }
 
-func (bn *blobNotifierMap) forRoot(root [32]byte) chan uint64 {
+func (bn *blobNotifierMap) forRoot(root [32]byte, slot primitives.Slot) chan uint64 {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	bn.Lock()
 	defer bn.Unlock()
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		c = make(chan uint64, maxBlobsPerBlock)
 		bn.notifiers[root] = c
 	}
 	return c
@@ -169,7 +171,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 	ctx, cancel := context.WithCancel(ctx)
 	bn := &blobNotifierMap{
 		notifiers: make(map[[32]byte]chan uint64),
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		seenIndex: make(map[[32]byte][]bool),
 	}
 	srv := &Service{
 		ctx:                  ctx,
@@ -266,69 +268,18 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 		return err
 	}
 	s.originBlockRoot = originRoot
-
-	if err := s.initializeHeadFromDB(s.ctx); err != nil {
-		return errors.Wrap(err, "could not set up chain info")
+	st, err := s.cfg.StateGen.Resume(s.ctx, s.cfg.FinalizedStateAtStartUp)
+	if err != nil {
+		return errors.Wrap(err, "could not get finalized state from db")
 	}
 	spawnCountdownIfPreGenesis(s.ctx, s.genesisTime, s.cfg.BeaconDB)
-
-	justified, err := s.cfg.BeaconDB.JustifiedCheckpoint(s.ctx)
-	if err != nil {
-		return errors.Wrap(err, "could not get justified checkpoint")
-	}
-	if justified == nil {
-		return errNilJustifiedCheckpoint
-	}
-	finalized, err := s.cfg.BeaconDB.FinalizedCheckpoint(s.ctx)
-	if err != nil {
-		return errors.Wrap(err, "could not get finalized checkpoint")
-	}
-	if finalized == nil {
-		return errNilFinalizedCheckpoint
-	}
-
-	fRoot := s.ensureRootNotZeros(bytesutil.ToBytes32(finalized.Root))
-	s.cfg.ForkChoiceStore.Lock()
-	defer s.cfg.ForkChoiceStore.Unlock()
-	if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(s.ctx, &forkchoicetypes.Checkpoint{Epoch: justified.Epoch,
-		Root: bytesutil.ToBytes32(justified.Root)}); err != nil {
-		return errors.Wrap(err, "could not update forkchoice's justified checkpoint")
-	}
-	if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: finalized.Epoch,
-		Root: bytesutil.ToBytes32(finalized.Root)}); err != nil {
-		return errors.Wrap(err, "could not update forkchoice's finalized checkpoint")
-	}
-	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(s.genesisTime.Unix()))
-
-	st, err := s.cfg.StateGen.StateByRoot(s.ctx, fRoot)
-	if err != nil {
-		return errors.Wrap(err, "could not get finalized checkpoint state")
-	}
-	finalizedBlock, err := s.cfg.BeaconDB.Block(s.ctx, fRoot)
-	if err != nil {
-		return errors.Wrap(err, "could not get finalized checkpoint block")
-	}
-	roblock, err := consensus_blocks.NewROBlockWithRoot(finalizedBlock, fRoot)
-	if err != nil {
-		return err
-	}
-	if err := s.cfg.ForkChoiceStore.InsertNode(s.ctx, st, roblock); err != nil {
-		return errors.Wrap(err, "could not insert finalized block to forkchoice")
-	}
-	if !features.Get().EnableStartOptimistic {
-		lastValidatedCheckpoint, err := s.cfg.BeaconDB.LastValidatedCheckpoint(s.ctx)
-		if err != nil {
-			return errors.Wrap(err, "could not get last validated checkpoint")
-		}
-		if bytes.Equal(finalized.Root, lastValidatedCheckpoint.Root) {
-			if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(s.ctx, fRoot); err != nil {
-				return errors.Wrap(err, "could not set finalized block as validated")
-			}
-		}
+	if err := s.setupForkchoice(st); err != nil {
+		return errors.Wrap(err, "could not set up forkchoice")
 	}
 	// not attempting to save initial sync blocks here, because there shouldn't be any until
 	// after the statefeed.Initialized event is fired (below)
-	if err := s.wsVerifier.VerifyWeakSubjectivity(s.ctx, finalized.Epoch); err != nil {
+	cp := s.FinalizedCheckpt()
+	if err := s.wsVerifier.VerifyWeakSubjectivity(s.ctx, cp.Epoch); err != nil {
 		// Exit run time if the node failed to verify weak subjectivity checkpoint.
 		return errors.Wrap(err, "could not verify initial checkpoint provided for chain sync")
 	}
@@ -337,7 +288,6 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err := s.clockSetter.SetClock(startup.NewClock(s.genesisTime, vr)); err != nil {
 		return errors.Wrap(err, "failed to initialize blockchain service")
 	}
-
 	return nil
 }
 
@@ -367,45 +317,36 @@ func (s *Service) originRootFromSavedState(ctx context.Context) ([32]byte, error
 	return genesisBlkRoot, nil
 }
 
-// initializeHeadFromDB uses the finalized checkpoint and head block found in the database to set the current head.
+// initializeHeadFromDB uses the finalized checkpoint and head block root from forkchoice to set the current head.
 // Note that this may block until stategen replays blocks between the finalized and head blocks
 // if the head sync flag was specified and the gap between the finalized and head blocks is at least 128 epochs long.
-func (s *Service) initializeHeadFromDB(ctx context.Context) error {
-	finalized, err := s.cfg.BeaconDB.FinalizedCheckpoint(ctx)
-	if err != nil {
-		return errors.Wrap(err, "could not get finalized checkpoint from db")
-	}
-	if finalized == nil {
-		// This should never happen. At chain start, the finalized checkpoint
-		// would be the genesis state and block.
-		return errors.New("no finalized epoch in the database")
-	}
-	finalizedRoot := s.ensureRootNotZeros(bytesutil.ToBytes32(finalized.Root))
-	var finalizedState state.BeaconState
-
-	finalizedState, err = s.cfg.StateGen.Resume(ctx, s.cfg.FinalizedStateAtStartUp)
-	if err != nil {
-		return errors.Wrap(err, "could not get finalized state from db")
-	}
-
-	if finalizedState == nil || finalizedState.IsNil() {
+func (s *Service) initializeHead(ctx context.Context, st state.BeaconState) error {
+	cp := s.FinalizedCheckpt()
+	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	if st == nil || st.IsNil() {
 		return errors.New("finalized state can't be nil")
 	}
 
-	finalizedBlock, err := s.getBlock(ctx, finalizedRoot)
+	s.cfg.ForkChoiceStore.RLock()
+	root := s.cfg.ForkChoiceStore.HighestReceivedBlockRoot()
+	s.cfg.ForkChoiceStore.RUnlock()
+	blk, err := s.cfg.BeaconDB.Block(ctx, root)
 	if err != nil {
-		return errors.Wrap(err, "could not get finalized block")
+		return errors.Wrap(err, "could not get head block")
 	}
-	if err := s.setHead(&head{
-		finalizedRoot,
-		finalizedBlock,
-		finalizedState,
-		finalizedBlock.Block().Slot(),
-		false,
-	}); err != nil {
+	if root != fRoot {
+		st, err = s.cfg.StateGen.StateByRoot(ctx, root)
+		if err != nil {
+			return errors.Wrap(err, "could not get head state")
+		}
+	}
+	if err := s.setHead(&head{root, blk, st, blk.Block().Slot(), false}); err != nil {
 		return errors.Wrap(err, "could not set head")
 	}
-
+	log.WithFields(logrus.Fields{
+		"root": fmt.Sprintf("%#x", root),
+		"slot": blk.Block().Slot(),
+	}).Info("Initialized head block from DB")
 	return nil
 }
 
@@ -524,7 +465,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon
 
 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()
-	gb, err := consensus_blocks.NewROBlockWithRoot(genesisBlk, genesisBlkRoot)
+	gb, err := blocks.NewROBlockWithRoot(genesisBlk, genesisBlkRoot)
 	if err != nil {
 		return err
 	}

beacon-chain/blockchain/service_test.go

@@ -587,7 +587,7 @@ func (s *MockClockSetter) SetClock(g *startup.Clock) error {
 func TestNotifyIndex(t *testing.T) {
 	// Initialize a blobNotifierMap
 	bn := &blobNotifierMap{
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		seenIndex: make(map[[32]byte][]bool),
 		notifiers: make(map[[32]byte]chan uint64),
 	}
 
@@ -596,7 +596,7 @@ func TestNotifyIndex(t *testing.T) {
 	copy(root[:], "exampleRoot")
 
 	// Test notifying a new index
-	bn.notifyIndex(root, 1)
+	bn.notifyIndex(root, 1, 1)
 	if !bn.seenIndex[root][1] {
 		t.Errorf("Index was not marked as seen")
 	}
@@ -607,13 +607,13 @@ func TestNotifyIndex(t *testing.T) {
 	}
 
 	// Test notifying an already seen index
-	bn.notifyIndex(root, 1)
+	bn.notifyIndex(root, 1, 1)
 	if len(bn.notifiers[root]) > 1 {
 		t.Errorf("Notifier channel should not receive multiple messages for the same index")
 	}
 
 	// Test notifying a new index again
-	bn.notifyIndex(root, 2)
+	bn.notifyIndex(root, 2, 1)
 	if !bn.seenIndex[root][2] {
 		t.Errorf("Index was not marked as seen")
 	}

beacon-chain/blockchain/setup_forchoice.go

@@ -0,0 +1,175 @@
+package blockchain
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+
+	"github.com/pkg/errors"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+)
+
+func (s *Service) setupForkchoice(st state.BeaconState) error {
+	if err := s.setupForkchoiceCheckpoints(); err != nil {
+		return errors.Wrap(err, "could not set up forkchoice checkpoints")
+	}
+	if err := s.setupForkchoiceTree(st); err != nil {
+		return errors.Wrap(err, "could not set up forkchoice root")
+	}
+	if err := s.initializeHead(s.ctx, st); err != nil {
+		return errors.Wrap(err, "could not initialize head from db")
+	}
+	return nil
+}
+
+func (s *Service) startupHeadRoot() [32]byte {
+	headStr := features.Get().ForceHead
+	cp := s.FinalizedCheckpt()
+	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	if headStr == "" {
+		return fRoot
+	}
+	if headStr == "head" {
+		root, err := s.cfg.BeaconDB.HeadBlockRoot()
+		if err != nil {
+			log.WithError(err).Error("could not get head block root, starting with finalized block as head")
+			return fRoot
+		}
+		log.Infof("Using Head root of %#x", root)
+		return root
+	}
+	root, err := bytesutil.DecodeHexWithLength(headStr, 32)
+	if err != nil {
+		log.WithError(err).Error("could not parse head root, starting with finalized block as head")
+		return fRoot
+	}
+	return [32]byte(root)
+}
+
+func (s *Service) setupForkchoiceTree(st state.BeaconState) error {
+	headRoot := s.startupHeadRoot()
+	cp := s.FinalizedCheckpt()
+	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	if err := s.setupForkchoiceRoot(st); err != nil {
+		return errors.Wrap(err, "could not set up forkchoice root")
+	}
+	if headRoot == fRoot {
+		return nil
+	}
+	blk, err := s.cfg.BeaconDB.Block(s.ctx, headRoot)
+	if err != nil {
+		log.WithError(err).Error("could not get head block, starting with finalized block as head")
+		return nil
+	}
+	if slots.ToEpoch(blk.Block().Slot()) < cp.Epoch {
+		log.WithField("headRoot", fmt.Sprintf("%#x", headRoot)).Error("head block is older than finalized block, starting with finalized block as head")
+		return nil
+	}
+	chain, err := s.buildForkchoiceChain(s.ctx, blk)
+	if err != nil {
+		log.WithError(err).Error("could not build forkchoice chain, starting with finalized block as head")
+		return nil
+	}
+	s.cfg.ForkChoiceStore.Lock()
+	defer s.cfg.ForkChoiceStore.Unlock()
+	return s.cfg.ForkChoiceStore.InsertChain(s.ctx, chain)
+}
+
+func (s *Service) buildForkchoiceChain(ctx context.Context, head interfaces.ReadOnlySignedBeaconBlock) ([]*forkchoicetypes.BlockAndCheckpoints, error) {
+	chain := []*forkchoicetypes.BlockAndCheckpoints{}
+	cp := s.FinalizedCheckpt()
+	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	jp := s.CurrentJustifiedCheckpt()
+	root, err := head.Block().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get head block root")
+	}
+	for {
+		roblock, err := blocks.NewROBlockWithRoot(head, root)
+		if err != nil {
+			return nil, err
+		}
+		// This chain sets the justified checkpoint for every block, including some that are older than jp.
+		// This should be however safe for forkchoice at startup. An alternative would be to hook during the
+		// block processing pipeline when setting the head state, to compute the right states for the justified
+		// checkpoint.
+		chain = append(chain, &forkchoicetypes.BlockAndCheckpoints{Block: roblock, JustifiedCheckpoint: jp, FinalizedCheckpoint: cp})
+		root = head.Block().ParentRoot()
+		if root == fRoot {
+			break
+		}
+		head, err = s.cfg.BeaconDB.Block(s.ctx, root)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get block")
+		}
+		if slots.ToEpoch(head.Block().Slot()) < cp.Epoch {
+			return nil, errors.New("head block is not a descendant of the finalized checkpoint")
+		}
+	}
+	return chain, nil
+}
+
+func (s *Service) setupForkchoiceRoot(st state.BeaconState) error {
+	cp := s.FinalizedCheckpt()
+	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	finalizedBlock, err := s.cfg.BeaconDB.Block(s.ctx, fRoot)
+	if err != nil {
+		return errors.Wrap(err, "could not get finalized checkpoint block")
+	}
+	roblock, err := blocks.NewROBlockWithRoot(finalizedBlock, fRoot)
+	if err != nil {
+		return err
+	}
+	if err := s.cfg.ForkChoiceStore.InsertNode(s.ctx, st, roblock); err != nil {
+		return errors.Wrap(err, "could not insert finalized block to forkchoice")
+	}
+	if !features.Get().EnableStartOptimistic {
+		lastValidatedCheckpoint, err := s.cfg.BeaconDB.LastValidatedCheckpoint(s.ctx)
+		if err != nil {
+			return errors.Wrap(err, "could not get last validated checkpoint")
+		}
+		if bytes.Equal(fRoot[:], lastValidatedCheckpoint.Root) {
+			if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(s.ctx, fRoot); err != nil {
+				return errors.Wrap(err, "could not set finalized block as validated")
+			}
+		}
+	}
+	return nil
+}
+
+func (s *Service) setupForkchoiceCheckpoints() error {
+	justified, err := s.cfg.BeaconDB.JustifiedCheckpoint(s.ctx)
+	if err != nil {
+		return errors.Wrap(err, "could not get justified checkpoint")
+	}
+	if justified == nil {
+		return errNilJustifiedCheckpoint
+	}
+	finalized, err := s.cfg.BeaconDB.FinalizedCheckpoint(s.ctx)
+	if err != nil {
+		return errors.Wrap(err, "could not get finalized checkpoint")
+	}
+	if finalized == nil {
+		return errNilFinalizedCheckpoint
+	}
+
+	fRoot := s.ensureRootNotZeros(bytesutil.ToBytes32(finalized.Root))
+	s.cfg.ForkChoiceStore.Lock()
+	defer s.cfg.ForkChoiceStore.Unlock()
+	if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(s.ctx, &forkchoicetypes.Checkpoint{Epoch: justified.Epoch,
+		Root: bytesutil.ToBytes32(justified.Root)}); err != nil {
+		return errors.Wrap(err, "could not update forkchoice's justified checkpoint")
+	}
+	if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: finalized.Epoch,
+		Root: fRoot}); err != nil {
+		return errors.Wrap(err, "could not update forkchoice's finalized checkpoint")
+	}
+	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(s.genesisTime.Unix()))
+	return nil
+}

beacon-chain/blockchain/setup_forkchoice_test.go

@@ -0,0 +1,128 @@
+package blockchain
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	logTest "github.com/sirupsen/logrus/hooks/test"
+)
+
+func Test_startupHeadRoot(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+	hook := logTest.NewGlobal()
+	cp := service.FinalizedCheckpt()
+	require.DeepEqual(t, cp.Root, params.BeaconConfig().ZeroHash[:])
+	gr := [32]byte{'r', 'o', 'o', 't'}
+	service.originBlockRoot = gr
+	require.NoError(t, service.cfg.BeaconDB.SaveGenesisBlockRoot(ctx, gr))
+	t.Run("start from finalized", func(t *testing.T) {
+		require.Equal(t, service.startupHeadRoot(), gr)
+	})
+	t.Run("head requested, error path", func(t *testing.T) {
+		resetCfg := features.InitWithReset(&features.Flags{
+			ForceHead: "head",
+		})
+		defer resetCfg()
+		require.Equal(t, service.startupHeadRoot(), gr)
+		require.LogsContain(t, hook, "could not get head block root, starting with finalized block as head")
+	})
+
+	st, _ := util.DeterministicGenesisState(t, 64)
+	hr := [32]byte{'h', 'e', 'a', 'd'}
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, st, hr), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, hr), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, hr))
+
+	t.Run("start from head", func(t *testing.T) {
+		resetCfg := features.InitWithReset(&features.Flags{
+			ForceHead: "head",
+		})
+		defer resetCfg()
+		require.Equal(t, service.startupHeadRoot(), hr)
+	})
+}
+
+func Test_setupForkchoiceTree_Finalized(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+
+	st, _ := util.DeterministicGenesisState(t, 64)
+	stateRoot, err := st.HashTreeRoot(ctx)
+	require.NoError(t, err, "Could not hash genesis state")
+
+	require.NoError(t, service.saveGenesisData(ctx, st))
+
+	genesis := blocks.NewGenesisBlock(stateRoot[:])
+	wsb, err := consensusblocks.NewSignedBeaconBlock(genesis)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb), "Could not save genesis block")
+	parentRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not get signing root")
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, st, parentRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, parentRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveJustifiedCheckpoint(ctx, &ethpb.Checkpoint{Root: parentRoot[:]}))
+	require.NoError(t, service.cfg.BeaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Root: parentRoot[:]}))
+	require.NoError(t, service.setupForkchoiceTree(st))
+	require.Equal(t, 1, service.cfg.ForkChoiceStore.NodeCount())
+}
+
+func Test_setupForkchoiceTree_Head(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+	resetCfg := features.InitWithReset(&features.Flags{
+		ForceHead: "head",
+	})
+	defer resetCfg()
+
+	genesisState, keys := util.DeterministicGenesisState(t, 64)
+	stateRoot, err := genesisState.HashTreeRoot(ctx)
+	require.NoError(t, err, "Could not hash genesis state")
+	genesis := blocks.NewGenesisBlock(stateRoot[:])
+	wsb, err := consensusblocks.NewSignedBeaconBlock(genesis)
+	require.NoError(t, err)
+	genesisRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not get signing root")
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb), "Could not save genesis block")
+	require.NoError(t, service.saveGenesisData(ctx, genesisState))
+
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, genesisState, genesisRoot), "Could not save genesis state")
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, genesisRoot), "Could not save genesis state")
+
+	st, err := service.HeadState(ctx)
+	require.NoError(t, err)
+	b, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), primitives.Slot(1))
+	require.NoError(t, err)
+	wsb, err = consensusblocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	root, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	preState, err := service.getBlockPreState(ctx, wsb.Block())
+	require.NoError(t, err)
+	postState, err := service.validateStateTransition(ctx, preState, wsb)
+	require.NoError(t, err)
+	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
+
+	b, err = util.GenerateFullBlock(postState, keys, util.DefaultBlockGenConfig(), primitives.Slot(2))
+	require.NoError(t, err)
+	wsb, err = consensusblocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	root, err = b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, preState))
+
+	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, root))
+	cp := service.FinalizedCheckpt()
+	fRoot := service.ensureRootNotZeros([32]byte(cp.Root))
+	require.NotEqual(t, fRoot, root)
+	require.Equal(t, root, service.startupHeadRoot())
+	require.NoError(t, service.setupForkchoiceTree(st))
+	require.Equal(t, 2, service.cfg.ForkChoiceStore.NodeCount())
+}

beacon-chain/blockchain/testing/mock.go

@@ -75,6 +75,7 @@ type ChainService struct {
 	SyncingRoot                 [32]byte
 	Blobs                       []blocks.VerifiedROBlob
 	TargetRoot                  [32]byte
+	MockHeadSlot                *primitives.Slot
 }
 
 func (s *ChainService) Ancestor(ctx context.Context, root []byte, slot primitives.Slot) ([]byte, error) {
@@ -334,6 +335,9 @@ func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.ReadOn
 
 // HeadSlot mocks HeadSlot method in chain service.
 func (s *ChainService) HeadSlot() primitives.Slot {
+	if s.MockHeadSlot != nil {
+		return *s.MockHeadSlot
+	}
 	if s.State == nil {
 		return 0
 	}

beacon-chain/builder/BUILD.bazel

@@ -3,6 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "log.go",
         "metric.go",
         "option.go",
         "service.go",