fixing beacon

fixing grpc issue
merging apiutil and httputil
2026-01-10 22:07:59 -05:00 · 2025-04-03 16:15:56 -05:00 · 2025-04-03 15:26:29 -05:00 · 2025-04-03 15:20:04 -05:00 · 2025-04-03 15:17:55 -05:00 · 2025-04-03 15:14:14 -05:00
527 changed files with 9197 additions and 5021 deletions
--- a/.github/workflows/changelog.yml
+++ b/.github/workflows/changelog.yml
@@ -12,7 +12,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout source code
-        uses: actions/checkout@v3
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0

      - name: Download unclog binary
        uses: dsaltares/fetch-gh-release-asset@aa2ab1243d6e0d5b405b973c89fa4d06a2d0fff7 # 1.1.2
@@ -23,7 +23,7 @@ jobs:

      - name: Get new changelog files
        id: new-changelog-files
-        uses: tj-actions/changed-files@v45
+        uses: OffchainLabs/gh-action-changed-files@9200e69727eb73eb060652b19946b8a2fdfb654b # v4.0.8
        with:
          files: |
            changelog/**.md
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -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",
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,139 @@ 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.

+## [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.
@@ -3122,4 +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
--- a/README.md
+++ b/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)
--- a/38
+++ b/38
@@ -255,7 +255,7 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.5.0-beta.2"
+consensus_spec_version = "v1.5.0-beta.4"

 bls_test_version = "v0.1.1"

@@ -271,7 +271,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-X/bMxbKg1clo2aFEjBoeuFq/U+BF1eQopgRP/7nI3Qg=",
+    integrity = "sha256-QG0NUqaCvP5lKaKKwF/fmeICZVjONMlb7EE+MtYl0C0=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

@@ -287,7 +287,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-WSxdri5OJGuNApW+odKle5UzToDyEOx+F3lMiqamJAg=",
+    integrity = "sha256-8NQngTSSqzW/j3tOUi3r5h+94ChRbLNWTt7BOGqr4+E=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

@@ -303,7 +303,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-LYE8l3y/zSt4YVrehrJ3ralqtgeYNildiIp+HR6+xAI=",
+    integrity = "sha256-gFqxbaBnJ7dtdoj0zFbVrtlHv/bLNuWjrTHkyCAjFjI=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

@@ -318,7 +318,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-jvZQ90qcJMTOqMsPO7sgeEVQmewZTHcz7LVDkNqwTFQ=",
+    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,
 )
@@ -365,9 +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(
@@ -381,9 +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(
--- a/api/BUILD.bazel
+++ b/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 = [
--- a/api/client/BUILD.bazel
+++ b/api/client/BUILD.bazel
@@ -4,17 +4,29 @@ go_library(
    name = "go_default_library",
    srcs = [
        "client.go",
-        "errors.go",
+        "json_rest_handler.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"],
+    srcs = [
+        "client_test.go",
+        "json_rest_handler_test.go",
+    ],
    embed = [":go_default_library"],
-    deps = ["//testing/require:go_default_library"],
+    deps = [
+        "//api/httputil:go_default_library",
+        "//api/server/structs:go_default_library",
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
 )
--- a/api/client/Mock/BUILD.bazel
+++ b/api/client/Mock/BUILD.bazel
@@ -0,0 +1,9 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["json_rest_handler_mock.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/Mock",
+    visibility = ["//visibility:public"],
+    deps = ["@org_uber_go_mock//gomock:go_default_library"],
+)
--- a/validator/client/beacon-api/mock/json_rest_handler_mock.go
+++ b/validator/client/beacon-api/mock/json_rest_handler_mock.go
@@ -7,7 +7,7 @@
 //

 // Package mock is a generated GoMock package.
-package mock
+package Mock

 import (
 	bytes "bytes"
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -7,12 +7,14 @@ go_library(
        "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",
        "//consensus-types/primitives:go_default_library",
@@ -33,8 +35,8 @@ go_test(
    ],
    embed = [":go_default_library"],
    deps = [
-        "//api/client:go_default_library",
        "//api/client/beacon/testing:go_default_library",
+        "//api/httputil:go_default_library",
        "//testing/require:go_default_library",
        "@org_uber_go_mock//gomock:go_default_library",
    ],
--- a/api/client/beacon/client.go
+++ b/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"
@@ -64,23 +64,6 @@ 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
-}
-
 // RenderGetBlockPath formats a block id into a path for the GetBlock API endpoint.
 func RenderGetBlockPath(id StateOrBlockId) string {
 	return path.Join(getSignedBlockPath, string(id))
@@ -114,8 +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
@@ -138,8 +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
@@ -206,7 +185,7 @@ 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],
--- a/api/client/beacon/client_test.go
+++ b/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",
@@ -92,7 +92,7 @@ func TestValidHostname(t *testing.T) {
 		{
 			name:    "hostname without port",
 			hostArg: "mydomain.org",
-			err:     client.ErrMalformedHostname,
+			err:     httputil.ErrMalformedHostname,
 		},
 		{
 			name:    "hostname with port",
--- a/api/client/beacon/template.go
+++ b/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)
+}
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -11,8 +11,7 @@ go_library(
    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/builder",
    visibility = ["//visibility:public"],
    deps = [
-        "//api:go_default_library",
-        "//api/client:go_default_library",
+        "//api/httputil:go_default_library",
        "//api/server:go_default_library",
        "//api/server/structs:go_default_library",
        "//config/fieldparams:go_default_library",
@@ -47,7 +46,7 @@ go_test(
    data = glob(["testdata/**"]),
    embed = [":go_default_library"],
    deps = [
-        "//api:go_default_library",
+        "//api/httputil:go_default_library",
        "//api/server/structs:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -13,9 +13,9 @@ import (
 	"text/template"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api"
-	"github.com/prysmaticlabs/prysm/v5/api/client"
+	"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"
@@ -35,9 +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)
@@ -52,6 +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) {
@@ -95,9 +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).
@@ -139,7 +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)
@@ -155,10 +167,6 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 	if err != nil {
 		return
 	}
-	if method == http.MethodPost {
-		req.Header.Set("Content-Type", api.JsonMediaType)
-	}
-	req.Header.Set("Accept", api.JsonMediaType)
 	req.Header.Add("User-Agent", version.BuildData())
 	for _, o := range opts {
 		o(req)
@@ -182,11 +190,12 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 		err = non200Err(r)
 		return
 	}
-	res, err = io.ReadAll(io.LimitReader(r.Body, client.MaxBodySize))
+	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
 }

@@ -216,64 +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)
-	if err != nil {
-		return nil, err
+	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)
+		}
 	}
-	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)
+	data, header, err := c.do(ctx, http.MethodGet, path, nil, getOpts)
+	if err != nil {
+		return nil, errors.Wrap(err, "error getting header from builder server")
 	}

-	ver, err := version.FromString(strings.ToLower(v.Version))
+	bid, err := c.parseHeaderResponse(data, header)
 	if err != nil {
-		return nil, errors.Wrap(err, fmt.Sprintf("unsupported header version %s", strings.ToLower(v.Version)))
+		return nil, errors.Wrapf(
+			err,
+			"error rendering exec header template with 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",
+			)
+		}
+		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 {
-		hr := &ExecHeaderResponseElectra{}
-		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 WrappedSignedBuilderBidElectra(p)
+		return c.parseHeaderElectra(data)
 	}
 	if ver >= 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)
-		}
-		p, err := hr.ToProto()
-		if err != nil {
-			return nil, errors.Wrapf(err, "could not extract proto message from header")
-		}
-		return WrappedSignedBuilderBidDeneb(p)
+		return c.parseHeaderDeneb(data)
 	}
 	if ver >= 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)
+		return c.parseHeaderCapella(data)
 	}
 	if ver >= 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)
+		return c.parseHeaderBellatrix(data)
 	}
-	return nil, fmt.Errorf("unsupported header version %s", strings.ToLower(v.Version))
+
+	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
@@ -288,70 +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("registrationCount", len(svr)).Debug("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
@@ -360,11 +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
 	}
@@ -375,12 +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(io.LimitReader(response.Body, client.MaxErrBodySize))
+	bodyBytes, err := io.ReadAll(io.LimitReader(response.Body, httputil.MaxErrBodySize))
 	var errMessage ErrorMessage
 	var body string
 	if err != nil {
@@ -390,6 +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
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -8,11 +8,10 @@ import (
 	"io"
 	"net/http"
 	"net/url"
-	"strconv"
 	"testing"

 	"github.com/prysmaticlabs/go-bitfield"
-	"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"
@@ -88,39 +87,84 @@ 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) {
-			require.Equal(t, api.JsonMediaType, r.Header.Get("Content-Type"))
-			require.Equal(t, api.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("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) {
@@ -176,6 +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)),
@@ -207,9 +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,
@@ -238,9 +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,
@@ -277,6 +412,56 @@ func TestClient_GetHeader(t *testing.T) {
 			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)
+		}
+	})
 	t.Run("deneb, too many kzg commitments", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -293,11 +478,12 @@ 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,
@@ -338,6 +524,61 @@ func TestClient_GetHeader(t *testing.T) {
 		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{
@@ -367,8 +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, api.JsonMediaType, r.Header.Get("Content-Type"))
-				require.Equal(t, api.JsonMediaType, 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)),
@@ -390,13 +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, api.JsonMediaType, r.Header.Get("Content-Type"))
-				require.Equal(t, api.JsonMediaType, 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)),
@@ -420,14 +701,56 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		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)
+	})
 	t.Run("deneb", 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("Eth-Consensus-Version"))
-				require.Equal(t, api.JsonMediaType, r.Header.Get("Content-Type"))
-				require.Equal(t, api.JsonMediaType, 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)
@@ -460,6 +783,140 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		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)
+	})
 	t.Run("mismatched versions, expected bellatrix got capella", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -586,7 +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"),
@@ -605,8 +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"),
@@ -620,7 +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"),
 				},
@@ -728,7 +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"),
@@ -747,8 +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"),
@@ -762,7 +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"),
@@ -875,7 +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"),
@@ -922,6 +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)
--- a/api/client/builder/errors.go
+++ b/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")
--- a/api/client/client.go
+++ b/api/client/client.go
@@ -8,12 +8,7 @@ import (
 	"net/url"

 	"github.com/pkg/errors"
-)
-
-const (
-	MaxBodySize      int64 = 1 << 23 // 8MB default, WithMaxBodySize can override
-	MaxBodySizeState int64 = 1 << 29 // 512MB
-	MaxErrBodySize   int64 = 1 << 17 // 128KB
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 )

 // Client is a wrapper object around the HTTP client.
@@ -35,7 +30,7 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {
 	c := &Client{
 		hc:          &http.Client{},
 		baseURL:     u,
-		maxBodySize: MaxBodySize,
+		maxBodySize: httputil.MaxBodySize,
 	}
 	for _, o := range opts {
 		o(c)
@@ -67,7 +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
 }
@@ -95,7 +90,7 @@ 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(io.LimitReader(r.Body, c.maxBodySize))
 	if err != nil {
--- a/api/client/client_test.go
+++ b/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 {
--- a/api/client/event/BUILD.bazel
+++ b/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",
    ],
--- a/api/client/event/event_stream.go
+++ b/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()),
 		}
 	}
 }
--- a/validator/client/beacon-api/json_rest_handler.go
+++ b/validator/client/beacon-api/json_rest_handler.go
@@ -1,4 +1,4 @@
-package beacon_api
+package client

 import (
 	"bytes"
@@ -9,8 +9,7 @@ import (
 	"strings"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api"
-	"github.com/prysmaticlabs/prysm/v5/network/httputil"
+	"github.com/prysmaticlabs/prysm/v5/api/httputil"
 )

 type JsonRestHandler interface {
@@ -88,7 +87,7 @@ func (c *BeaconApiJsonRestHandler) Post(
 	for headerKey, headerValue := range headers {
 		req.Header.Set(headerKey, headerValue)
 	}
-	req.Header.Set("Content-Type", api.JsonMediaType)
+	req.Header.Set("Content-Type", httputil.JsonMediaType)

 	httpResp, err := c.client.Do(req)
 	if err != nil {
@@ -109,7 +108,7 @@ func decodeResp(httpResp *http.Response, resp interface{}) error {
 		return errors.Wrapf(err, "failed to read response body for %s", httpResp.Request.URL)
 	}

-	if !strings.Contains(httpResp.Header.Get("Content-Type"), api.JsonMediaType) {
+	if !strings.Contains(httpResp.Header.Get("Content-Type"), httputil.JsonMediaType) {
 		// 2XX codes are a success
 		if strings.HasPrefix(httpResp.Status, "2") {
 			return nil
--- a/validator/client/beacon-api/json_rest_handler_test.go
+++ b/validator/client/beacon-api/json_rest_handler_test.go
@@ -1,4 +1,4 @@
-package beacon_api
+package client

 import (
 	"bytes"
@@ -11,9 +11,8 @@ import (
 	"time"

 	"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/network/httputil"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
@@ -33,7 +32,7 @@ func TestGet(t *testing.T) {
 		marshalledJson, err := json.Marshal(genesisJson)
 		require.NoError(t, err)

-		w.Header().Set("Content-Type", api.JsonMediaType)
+		w.Header().Set("Content-Type", httputil.JsonMediaType)
 		_, err = w.Write(marshalledJson)
 		require.NoError(t, err)
 	})
@@ -67,7 +66,7 @@ func TestPost(t *testing.T) {
 	mux.HandleFunc(endpoint, func(w http.ResponseWriter, r *http.Request) {
 		// Make sure the request headers have been set
 		assert.Equal(t, "bar", r.Header.Get("foo"))
-		assert.Equal(t, api.JsonMediaType, r.Header.Get("Content-Type"))
+		assert.Equal(t, httputil.JsonMediaType, r.Header.Get("Content-Type"))

 		// Make sure the data matches
 		receivedBytes := make([]byte, len(dataBytes))
@@ -79,7 +78,7 @@ func TestPost(t *testing.T) {
 		marshalledJson, err := json.Marshal(genesisJson)
 		require.NoError(t, err)

-		w.Header().Set("Content-Type", api.JsonMediaType)
+		w.Header().Set("Content-Type", httputil.JsonMediaType)
 		_, err = w.Write(marshalledJson)
 		require.NoError(t, err)
 	})
@@ -115,7 +114,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "200",
 			StatusCode: http.StatusOK,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.OctetStreamMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.OctetStreamMediaType}},
 		}
 		require.NoError(t, decodeResp(r, nil))
 	})
@@ -125,7 +124,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "204",
 			StatusCode: http.StatusNoContent,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.OctetStreamMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.OctetStreamMediaType}},
 		}
 		require.NoError(t, decodeResp(r, nil))
 	})
@@ -137,7 +136,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "500",
 			StatusCode: http.StatusInternalServerError,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.OctetStreamMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.OctetStreamMediaType}},
 		}
 		err = decodeResp(r, nil)
 		errJson := &httputil.DefaultJsonError{}
@@ -154,7 +153,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "200",
 			StatusCode: http.StatusOK,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.JsonMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.JsonMediaType}},
 		}
 		resp := &j{}
 		require.NoError(t, decodeResp(r, resp))
@@ -166,7 +165,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "200",
 			StatusCode: http.StatusOK,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.JsonMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.JsonMediaType}},
 		}
 		require.NoError(t, decodeResp(r, nil))
 	})
@@ -176,7 +175,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "204",
 			StatusCode: http.StatusNoContent,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.JsonMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.JsonMediaType}},
 		}
 		require.NoError(t, decodeResp(r, nil))
 	})
@@ -189,7 +188,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "500",
 			StatusCode: http.StatusInternalServerError,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.JsonMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.JsonMediaType}},
 		}
 		err = decodeResp(r, nil)
 		errJson := &httputil.DefaultJsonError{}
@@ -205,7 +204,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "200",
 			StatusCode: http.StatusOK,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.JsonMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.JsonMediaType}},
 			Request:    &http.Request{},
 		}
 		resp := &j{}
@@ -220,7 +219,7 @@ func Test_decodeResp(t *testing.T) {
 			Status:     "500",
 			StatusCode: http.StatusInternalServerError,
 			Body:       io.NopCloser(&body),
-			Header:     map[string][]string{"Content-Type": {api.JsonMediaType}},
+			Header:     map[string][]string{"Content-Type": {httputil.JsonMediaType}},
 			Request:    &http.Request{},
 		}
 		err = decodeResp(r, nil)
--- a/api/grpcutil/BUILD.bazel
+++ b/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",
--- a/api/grpcutil/common.go
+++ b/api/grpcutil/common.go
@@ -1,4 +1,4 @@
-package grpc
+package grpcutil

 import (
 	"context"
--- a/api/grpcutil/common_test.go
+++ b/api/grpcutil/common_test.go
@@ -1,4 +1,4 @@
-package grpc
+package grpcutil

 import (
 	"context"
--- a/api/grpcutil/parameters.go
+++ b/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.
--- a/network/httputil/BUILD.bazel
+++ b/network/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",
    ],
--- a/api/httputil/common.go
+++ b/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())
+}
--- a/api/httputil/common_test.go
+++ b/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)
+}
--- a/api/httputil/constants.go
+++ b/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
+)
--- a/api/httputil/errors.go
+++ b/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")

@@ -24,6 +32,9 @@ var ErrInvalidNodeVersion = errors.New("invalid node version response")
 // ErrConnectionIssue represents a connection problem.
 var ErrConnectionIssue = errors.New("could not connect")

+// ErrNotSupported represents a connection to a beacon node that is non prysm or wrong version
+var ErrNotSupported = errors.New("endpoint not supported")
+
 // Non200Err is a function that parses an HTTP response to handle responses that are not 200 with a formatted error.
 func Non200Err(r *http.Response) error {
 	b, err := io.ReadAll(io.LimitReader(r.Body, MaxErrBodySize))
--- a/api/httputil/headers.go
+++ b/api/httputil/headers.go
@@ -1,4 +1,4 @@
-package api
+package httputil

 import "net/http"

--- a/network/httputil/reader.go
+++ b/network/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
 }
--- a/network/httputil/reader_test.go
+++ b/network/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)
 	})
--- a/network/httputil/writer.go
+++ b/network/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")
--- a/api/server/middleware/BUILD.bazel
+++ b/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",
    ],
--- a/api/server/middleware/middleware_test.go
+++ b/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,
 		},
 		{
--- a/api/server/structs/endpoints_beacon.go
+++ b/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"`
 }
--- a/api/server/structs/endpoints_events.go
+++ b/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"`
 }
--- a/async/event/subscription.go
+++ b/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:
--- a/beacon-chain/blockchain/chain_info_forkchoice.go
+++ b/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
+}
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -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))
+}
--- a/beacon-chain/blockchain/error.go
+++ b/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")
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -69,6 +69,18 @@ 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())
 	}
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/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)
--- a/beacon-chain/blockchain/forkchoice_update_execution.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution.go
@@ -105,9 +105,7 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 	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(s.ctx, args.headState, args.headBlock); err != nil {
-		log.WithError(err).Error("could not prune attestations from pool")
-	}
+	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)
 	return nil
 }

--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -410,7 +410,11 @@ func (s *Service) saveOrphanedOperations(ctx context.Context, orphanedRoot [32]b
 					return err
 				}
 			} else {
-				if a.IsAggregated() {
+				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
 					}
--- a/beacon-chain/blockchain/head_test.go
+++ b/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()
--- a/beacon-chain/blockchain/process_attestation_helpers.go
+++ b/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 {
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -175,6 +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
@@ -423,13 +426,12 @@ func (s *Service) savePostStateInfo(ctx context.Context, r [32]byte, b interface

 // 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) error {
+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")
 		}
 	}
-	return nil
 }

 func (s *Service) pruneCoveredAttsFromPool(ctx context.Context, headState state.BeaconState, att ethpb.Att) error {
--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
@@ -126,11 +126,10 @@ func Test_pruneAttsFromPool_Electra(t *testing.T) {
 	// into the correct number of aggregates.
 	require.Equal(t, 4, len(committees))

-	require.NoError(t, s.pruneAttsFromPool(ctx, st, rob))
+	s.pruneAttsFromPool(ctx, st, rob)
 	require.LogsDoNotContain(t, logHook, "Could not prune attestations")

-	attsInPool, err := s.cfg.AttPool.UnaggregatedAttestations()
-	require.NoError(t, err)
+	attsInPool := s.cfg.AttPool.UnaggregatedAttestations()
 	assert.Equal(t, 0, len(attsInPool))
 	attsInPool = s.cfg.AttPool.AggregatedAttestations()
 	require.Equal(t, 1, len(attsInPool))
@@ -934,7 +933,7 @@ 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(context.Background(), nil /* state not needed pre-Electra */, 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())
 }
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -16,6 +16,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/slasher/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/consensus-types/primitives"
@@ -64,6 +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")
--- a/beacon-chain/blockchain/receive_block_test.go
+++ b/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)
--- a/beacon-chain/blockchain/testing/mock.go
+++ b/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
 	}
--- a/beacon-chain/builder/BUILD.bazel
+++ b/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",
--- a/beacon-chain/builder/log.go
+++ b/beacon-chain/builder/log.go
@@ -0,0 +1,5 @@
+package builder
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "builder")
--- a/beacon-chain/builder/option.go
+++ b/beacon-chain/builder/option.go
@@ -14,10 +14,16 @@ type Option func(s *Service) error
 // FlagOptions for builder service flag configurations.
 func FlagOptions(c *cli.Context) ([]Option, error) {
 	endpoint := c.String(flags.MevRelayEndpoint.Name)
+	sszEnabled := c.Bool(flags.EnableBuilderSSZ.Name)
 	var client *builder.Client
 	if endpoint != "" {
+		var opts []builder.ClientOpt
+		if sszEnabled {
+			log.Info("Using APIs with SSZ enabled")
+			opts = append(opts, builder.WithSSZ())
+		}
 		var err error
-		client, err = builder.NewClient(endpoint)
+		client, err = builder.NewClient(endpoint, opts...)
 		if err != nil {
 			return nil, err
 		}
--- a/beacon-chain/builder/service.go
+++ b/beacon-chain/builder/service.go
@@ -17,7 +17,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	log "github.com/sirupsen/logrus"
 )

 // ErrNoBuilder is used when builder endpoint is not configured.
--- a/beacon-chain/cache/tracked_validators.go
+++ b/beacon-chain/cache/tracked_validators.go
@@ -25,7 +25,7 @@ type (
 	}

 	TrackedValidatorsCache struct {
-		trackedValidators cache.Cache
+		trackedValidators *cache.Cache
 	}
 )

@@ -50,7 +50,7 @@ var (
 // NewTrackedValidatorsCache creates a new cache for tracking validators.
 func NewTrackedValidatorsCache() *TrackedValidatorsCache {
 	return &TrackedValidatorsCache{
-		trackedValidators: *cache.New(defaultExpiration, cleanupInterval),
+		trackedValidators: cache.New(defaultExpiration, cleanupInterval),
 	}
 }

--- a/beacon-chain/core/altair/attestation.go
+++ b/beacon-chain/core/altair/attestation.go
@@ -165,7 +165,7 @@ func AddValidatorFlag(flag, flagPosition uint8) (uint8, error) {
 //	        if flag_index in participation_flag_indices and not has_flag(epoch_participation[index], flag_index):
 //	            epoch_participation[index] = add_flag(epoch_participation[index], flag_index)
 //	            proposer_reward_numerator += get_base_reward(state, index) * weight
-func EpochParticipation(beaconState state.BeaconState, indices []uint64, epochParticipation []byte, participatedFlags map[uint8]bool, totalBalance uint64) (uint64, []byte, error) {
+func EpochParticipation(beaconState state.ReadOnlyBeaconState, indices []uint64, epochParticipation []byte, participatedFlags map[uint8]bool, totalBalance uint64) (uint64, []byte, error) {
 	cfg := params.BeaconConfig()
 	sourceFlagIndex := cfg.TimelySourceFlagIndex
 	targetFlagIndex := cfg.TimelyTargetFlagIndex
@@ -267,7 +267,7 @@ func RewardProposer(ctx context.Context, beaconState state.BeaconState, proposer
 //	    participation_flag_indices.append(TIMELY_HEAD_FLAG_INDEX)
 //
 //	return participation_flag_indices
-func AttestationParticipationFlagIndices(beaconState state.BeaconState, data *ethpb.AttestationData, delay primitives.Slot) (map[uint8]bool, error) {
+func AttestationParticipationFlagIndices(beaconState state.ReadOnlyBeaconState, data *ethpb.AttestationData, delay primitives.Slot) (map[uint8]bool, error) {
 	currEpoch := time.CurrentEpoch(beaconState)
 	var justifiedCheckpt *ethpb.Checkpoint
 	if data.Target.Epoch == currEpoch {
@@ -312,7 +312,7 @@ func AttestationParticipationFlagIndices(beaconState state.BeaconState, data *et
 //	is_matching_source = data.source == justified_checkpoint
 //	is_matching_target = is_matching_source and data.target.root == get_block_root(state, data.target.epoch)
 //	is_matching_head = is_matching_target and data.beacon_block_root == get_block_root_at_slot(state, data.slot)
-func MatchingStatus(beaconState state.BeaconState, data *ethpb.AttestationData, cp *ethpb.Checkpoint) (matchedSrc, matchedTgt, matchedHead bool, err error) {
+func MatchingStatus(beaconState state.ReadOnlyBeaconState, data *ethpb.AttestationData, cp *ethpb.Checkpoint) (matchedSrc, matchedTgt, matchedHead bool, err error) {
 	matchedSrc = attestation.CheckPointIsEqual(data.Source, cp)

 	r, err := helpers.BlockRoot(beaconState, data.Target.Epoch)
--- a/beacon-chain/core/electra/BUILD.bazel
+++ b/beacon-chain/core/electra/BUILD.bazel
@@ -29,6 +29,7 @@ go_library(
        "//beacon-chain/core/validators:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/state-native:go_default_library",
+        "//beacon-chain/state/state-native/custom-types:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
@@ -39,6 +40,7 @@ go_library(
        "//monitoring/tracing/trace:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/attestation:go_default_library",
        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
@@ -79,7 +81,6 @@ go_test(
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//crypto/bls:go_default_library",
-        "//crypto/bls/common:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
--- a/beacon-chain/core/electra/attestation.go
+++ b/beacon-chain/core/electra/attestation.go
@@ -1,7 +1,94 @@
 package electra

-import "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/altair"
+import (
+	"context"
+	"fmt"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/altair"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	customtypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native/custom-types"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
+)

 var (
 	ProcessAttestationsNoVerifySignature = altair.ProcessAttestationsNoVerifySignature
 )
+
+// GetProposerRewardNumerator returns the numerator of the proposer reward for an attestation.
+func GetProposerRewardNumerator(
+	ctx context.Context,
+	st state.ReadOnlyBeaconState,
+	att ethpb.Att,
+	totalBalance uint64,
+) (uint64, error) {
+	data := att.GetData()
+
+	delay, err := st.Slot().SafeSubSlot(data.Slot)
+	if err != nil {
+		return 0, fmt.Errorf("attestation slot %d exceeds state slot %d", data.Slot, st.Slot())
+	}
+
+	flags, err := altair.AttestationParticipationFlagIndices(st, data, delay)
+	if err != nil {
+		return 0, err
+	}
+
+	committees, err := helpers.AttestationCommitteesFromState(ctx, st, att)
+	if err != nil {
+		return 0, err
+	}
+
+	indices, err := attestation.AttestingIndices(att, committees...)
+	if err != nil {
+		return 0, err
+	}
+
+	var participation customtypes.ReadOnlyParticipation
+	if data.Target.Epoch == time.CurrentEpoch(st) {
+		participation, err = st.CurrentEpochParticipationReadOnly()
+	} else {
+		participation, err = st.PreviousEpochParticipationReadOnly()
+	}
+	if err != nil {
+		return 0, err
+	}
+
+	cfg := params.BeaconConfig()
+	var rewardNumerator uint64
+	for _, index := range indices {
+		if index >= uint64(participation.Len()) {
+			return 0, fmt.Errorf("index %d exceeds participation length %d", index, participation.Len())
+		}
+
+		br, err := altair.BaseRewardWithTotalBalance(st, primitives.ValidatorIndex(index), totalBalance)
+		if err != nil {
+			return 0, err
+		}
+
+		for _, entry := range []struct {
+			flagIndex uint8
+			weight    uint64
+		}{
+			{cfg.TimelySourceFlagIndex, cfg.TimelySourceWeight},
+			{cfg.TimelyTargetFlagIndex, cfg.TimelyTargetWeight},
+			{cfg.TimelyHeadFlagIndex, cfg.TimelyHeadWeight},
+		} {
+			if flags[entry.flagIndex] { // If set, the validator voted correctly for the attestation given flag index.
+				hasVoted, err := altair.HasValidatorFlag(participation.At(index), entry.flagIndex)
+				if err != nil {
+					return 0, err
+				}
+				if !hasVoted { // If set, the validator has already voted in the beacon state so we don't double count.
+					rewardNumerator += br * entry.weight
+				}
+			}
+		}
+	}
+
+	return rewardNumerator, nil
+}
--- a/beacon-chain/core/electra/consolidations.go
+++ b/beacon-chain/core/electra/consolidations.go
@@ -211,7 +211,7 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		if npc, err := st.NumPendingConsolidations(); err != nil {
 			return fmt.Errorf("failed to fetch number of pending consolidations: %w", err) // This should never happen.
 		} else if npc >= pcLimit {
-			return nil
+			continue
 		}

 		activeBal, err := helpers.TotalActiveBalance(st)
@@ -220,7 +220,7 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		}
 		churnLimit := helpers.ConsolidationChurnLimit(primitives.Gwei(activeBal))
 		if churnLimit <= primitives.Gwei(params.BeaconConfig().MinActivationBalance) {
-			return nil
+			continue
 		}

 		srcIdx, ok := st.ValidatorIndexByPubkey(sourcePubkey)
--- a/beacon-chain/core/electra/consolidations_test.go
+++ b/beacon-chain/core/electra/consolidations_test.go
@@ -415,6 +415,44 @@ func TestProcessConsolidationRequests(t *testing.T) {
 				require.Equal(t, params.BeaconConfig().FarFutureEpoch, src.WithdrawableEpoch, "source validator withdrawable epoch should not be updated")
 			},
 		},
+		{
+			name: "pending consolidations limit reached and compounded consolidation after",
+			state: func() state.BeaconState {
+				st := &eth.BeaconStateElectra{
+					Slot:                  params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().ShardCommitteePeriod)),
+					Validators:            createValidatorsWithTotalActiveBalance(32000000000000000), // 32M ETH
+					PendingConsolidations: make([]*eth.PendingConsolidation, params.BeaconConfig().PendingConsolidationsLimit),
+				}
+				// To allow compounding consolidation requests.
+				st.Validators[3].WithdrawalCredentials[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+				s, err := state_native.InitializeFromProtoElectra(st)
+				require.NoError(t, err)
+				return s
+			}(),
+			reqs: []*enginev1.ConsolidationRequest{
+				{
+					SourceAddress: append(bytesutil.PadTo(nil, 19), byte(1)),
+					SourcePubkey:  []byte("val_1"),
+					TargetPubkey:  []byte("val_2"),
+				},
+				{
+					SourceAddress: append(bytesutil.PadTo(nil, 19), byte(3)),
+					SourcePubkey:  []byte("val_3"),
+					TargetPubkey:  []byte("val_3"),
+				},
+			},
+			validate: func(t *testing.T, st state.BeaconState) {
+				// Verify a pending consolidation is created.
+				numPC, err := st.NumPendingConsolidations()
+				require.NoError(t, err)
+				require.Equal(t, params.BeaconConfig().PendingConsolidationsLimit, numPC)
+
+				// Verify that the last consolidation was included
+				src, err := st.ValidatorAtIndex(3)
+				require.NoError(t, err)
+				require.Equal(t, params.BeaconConfig().CompoundingWithdrawalPrefixByte, src.WithdrawalCredentials[0], "source validator was not compounded")
+			},
+		},
 	}

 	for _, tt := range tests {
--- a/beacon-chain/core/electra/deposits.go
+++ b/beacon-chain/core/electra/deposits.go
@@ -374,47 +374,38 @@ func ProcessPendingDeposits(ctx context.Context, st state.BeaconState, activeBal

 // batchProcessNewPendingDeposits should only be used to process new deposits that require validator registration
 func batchProcessNewPendingDeposits(ctx context.Context, state state.BeaconState, pendingDeposits []*ethpb.PendingDeposit) error {
-	// Return early if there are no deposits to process
 	if len(pendingDeposits) == 0 {
 		return nil
 	}

-	// Try batch verification of all deposit signatures
 	allSignaturesVerified, err := blocks.BatchVerifyPendingDepositsSignatures(ctx, pendingDeposits)
 	if err != nil {
 		return errors.Wrap(err, "batch signature verification failed")
 	}

-	// Process each deposit individually
-	for _, pendingDeposit := range pendingDeposits {
-		validSignature := allSignaturesVerified
+	for _, pd := range pendingDeposits {
+		validSig := allSignaturesVerified

-		// If batch verification failed, check the individual deposit signature
 		if !allSignaturesVerified {
-			validSignature, err = blocks.IsValidDepositSignature(&ethpb.Deposit_Data{
-				PublicKey:             bytesutil.SafeCopyBytes(pendingDeposit.PublicKey),
-				WithdrawalCredentials: bytesutil.SafeCopyBytes(pendingDeposit.WithdrawalCredentials),
-				Amount:                pendingDeposit.Amount,
-				Signature:             bytesutil.SafeCopyBytes(pendingDeposit.Signature),
+			validSig, err = blocks.IsValidDepositSignature(&ethpb.Deposit_Data{
+				PublicKey:             bytesutil.SafeCopyBytes(pd.PublicKey),
+				WithdrawalCredentials: bytesutil.SafeCopyBytes(pd.WithdrawalCredentials),
+				Amount:                pd.Amount,
+				Signature:             bytesutil.SafeCopyBytes(pd.Signature),
 			})
 			if err != nil {
 				return errors.Wrap(err, "individual deposit signature verification failed")
 			}
 		}

-		// Add validator to the registry if the signature is valid
-		if validSignature {
-			_, has := state.ValidatorIndexByPubkey(bytesutil.ToBytes48(pendingDeposit.PublicKey))
-			if has {
-				index, _ := state.ValidatorIndexByPubkey(bytesutil.ToBytes48(pendingDeposit.PublicKey))
-				if err := helpers.IncreaseBalance(state, index, pendingDeposit.Amount); err != nil {
-					return errors.Wrap(err, "could not increase balance")
-				}
-			} else {
-				err = AddValidatorToRegistry(state, pendingDeposit.PublicKey, pendingDeposit.WithdrawalCredentials, pendingDeposit.Amount)
-				if err != nil {
-					return errors.Wrap(err, "failed to add validator to registry")
-				}
+		pubkey := bytesutil.ToBytes48(pd.PublicKey)
+		if index, exists := state.ValidatorIndexByPubkey(pubkey); exists {
+			if err := helpers.IncreaseBalance(state, index, pd.Amount); err != nil {
+				return errors.Wrap(err, "could not increase balance")
+			}
+		} else if validSig {
+			if err := AddValidatorToRegistry(state, pd.PublicKey, pd.WithdrawalCredentials, pd.Amount); err != nil {
+				return errors.Wrap(err, "failed to add validator to registry")
 			}
 		}
 	}
--- a/beacon-chain/core/electra/deposits_test.go
+++ b/beacon-chain/core/electra/deposits_test.go
@@ -14,7 +14,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
-	"github.com/prysmaticlabs/prysm/v5/crypto/bls/common"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -196,7 +195,7 @@ func TestProcessPendingDeposits(t *testing.T) {
 			},
 		},
 		{
-			name: "process excess balance that uses a point to infinity signature, processed as a topup",
+			name: "process excess balance as a topup",
 			state: func() state.BeaconState {
 				excessBalance := uint64(100)
 				st := stateWithActiveBalanceETH(t, 32)
@@ -209,7 +208,6 @@ func TestProcessPendingDeposits(t *testing.T) {
 				validators[0].PublicKey = sk.PublicKey().Marshal()
 				validators[0].WithdrawalCredentials = wc
 				dep := stateTesting.GeneratePendingDeposit(t, sk, excessBalance, bytesutil.ToBytes32(wc), 0)
-				dep.Signature = common.InfiniteSignature[:]
 				require.NoError(t, st.SetValidators(validators))
 				require.NoError(t, st.SetPendingDeposits([]*eth.PendingDeposit{dep}))
 				return st
@@ -309,7 +307,7 @@ func TestProcessPendingDeposits(t *testing.T) {
 }

 func TestBatchProcessNewPendingDeposits(t *testing.T) {
-	t.Run("invalid batch initiates correct individual validation", func(t *testing.T) {
+	t.Run("one valid deposit one garbage deposit", func(t *testing.T) {
 		st := stateWithActiveBalanceETH(t, 0)
 		require.Equal(t, 0, len(st.Validators()))
 		require.Equal(t, 0, len(st.Balances()))
@@ -320,13 +318,47 @@ func TestBatchProcessNewPendingDeposits(t *testing.T) {
 		wc[31] = byte(0)
 		validDep := stateTesting.GeneratePendingDeposit(t, sk, params.BeaconConfig().MinActivationBalance, bytesutil.ToBytes32(wc), 0)
 		invalidDep := &eth.PendingDeposit{PublicKey: make([]byte, 48)}
-		// have a combination of valid and invalid deposits
 		deps := []*eth.PendingDeposit{validDep, invalidDep}
 		require.NoError(t, electra.BatchProcessNewPendingDeposits(context.Background(), st, deps))
-		// successfully added to register
 		require.Equal(t, 1, len(st.Validators()))
 		require.Equal(t, 1, len(st.Balances()))
 	})
+
+	t.Run("two valid deposits from same key", func(t *testing.T) {
+		st := stateWithActiveBalanceETH(t, 0)
+		require.Equal(t, 0, len(st.Validators()))
+		require.Equal(t, 0, len(st.Balances()))
+		sk, err := bls.RandKey()
+		require.NoError(t, err)
+		wc := make([]byte, 32)
+		wc[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+		wc[31] = byte(0)
+		validDep := stateTesting.GeneratePendingDeposit(t, sk, params.BeaconConfig().MinActivationBalance, bytesutil.ToBytes32(wc), 0)
+		deps := []*eth.PendingDeposit{validDep, validDep}
+		require.NoError(t, electra.BatchProcessNewPendingDeposits(context.Background(), st, deps))
+		require.Equal(t, 1, len(st.Validators()))
+		require.Equal(t, 1, len(st.Balances()))
+		require.Equal(t, params.BeaconConfig().MinActivationBalance*2, st.Balances()[0])
+	})
+
+	t.Run("one valid one with invalid signature deposit", func(t *testing.T) {
+		st := stateWithActiveBalanceETH(t, 0)
+		require.Equal(t, 0, len(st.Validators()))
+		require.Equal(t, 0, len(st.Balances()))
+		sk, err := bls.RandKey()
+		require.NoError(t, err)
+		wc := make([]byte, 32)
+		wc[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+		wc[31] = byte(0)
+		validDep := stateTesting.GeneratePendingDeposit(t, sk, params.BeaconConfig().MinActivationBalance, bytesutil.ToBytes32(wc), 0)
+		invalidSigDep := stateTesting.GeneratePendingDeposit(t, sk, params.BeaconConfig().MinActivationBalance, bytesutil.ToBytes32(wc), 0)
+		invalidSigDep.Signature = make([]byte, 96)
+		deps := []*eth.PendingDeposit{validDep, invalidSigDep}
+		require.NoError(t, electra.BatchProcessNewPendingDeposits(context.Background(), st, deps))
+		require.Equal(t, 1, len(st.Validators()))
+		require.Equal(t, 1, len(st.Balances()))
+		require.Equal(t, 2*params.BeaconConfig().MinActivationBalance, st.Balances()[0])
+	})
 }

 func TestProcessDepositRequests(t *testing.T) {
@@ -558,7 +590,6 @@ func TestApplyPendingDeposit_TopUp(t *testing.T) {
 	validators[0].PublicKey = sk.PublicKey().Marshal()
 	validators[0].WithdrawalCredentials = wc
 	dep := stateTesting.GeneratePendingDeposit(t, sk, excessBalance, bytesutil.ToBytes32(wc), 0)
-	dep.Signature = common.InfiniteSignature[:]
 	require.NoError(t, st.SetValidators(validators))

 	require.NoError(t, electra.ApplyPendingDeposit(context.Background(), st, dep))
--- a/beacon-chain/core/feed/operation/BUILD.bazel
+++ b/beacon-chain/core/feed/operation/BUILD.bazel
@@ -11,6 +11,7 @@ go_library(
    deps = [
        "//async/event:go_default_library",
        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
    ],
 )
--- a/beacon-chain/core/feed/operation/events.go
+++ b/beacon-chain/core/feed/operation/events.go
@@ -3,6 +3,7 @@ package operation

 import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 )

@@ -35,6 +36,9 @@ const (

 	// SingleAttReceived is sent after a single attestation object is received from gossip or rpc
 	SingleAttReceived = 9
+
+	// BlockGossipReceived is sent after a block has been received from gossip or API that passes validation rules.
+	BlockGossipReceived = 10
 )

 // UnAggregatedAttReceivedData is the data sent with UnaggregatedAttReceived events.
@@ -85,3 +89,9 @@ type AttesterSlashingReceivedData struct {
 type SingleAttReceivedData struct {
 	Attestation ethpb.Att
 }
+
+// BlockGossipReceivedData is the data sent with BlockGossipReceived events.
+type BlockGossipReceivedData struct {
+	// SignedBlock is the block that was received.
+	SignedBlock interfaces.ReadOnlySignedBeaconBlock
+}
--- a/beacon-chain/core/helpers/attestation.go
+++ b/beacon-chain/core/helpers/attestation.go
@@ -10,7 +10,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	prysmTime "github.com/prysmaticlabs/prysm/v5/time"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )
@@ -86,15 +85,7 @@ func IsAggregator(committeeCount uint64, slotSig []byte) (bool, error) {
 //
 //	return uint64((committees_since_epoch_start + committee_index) % ATTESTATION_SUBNET_COUNT)
 func ComputeSubnetForAttestation(activeValCount uint64, att ethpb.Att) uint64 {
-	if att.Version() >= version.Electra {
-		committeeIndex := 0
-		committeeIndices := att.CommitteeBitsVal().BitIndices()
-		if len(committeeIndices) > 0 {
-			committeeIndex = committeeIndices[0]
-		}
-		return ComputeSubnetFromCommitteeAndSlot(activeValCount, primitives.CommitteeIndex(committeeIndex), att.GetData().Slot)
-	}
-	return ComputeSubnetFromCommitteeAndSlot(activeValCount, att.GetData().CommitteeIndex, att.GetData().Slot)
+	return ComputeSubnetFromCommitteeAndSlot(activeValCount, att.GetCommitteeIndex(), att.GetData().Slot)
 }

 // ComputeSubnetFromCommitteeAndSlot is a flattened version of ComputeSubnetForAttestation where we only pass in
--- a/beacon-chain/db/filters/BUILD.bazel
+++ b/beacon-chain/db/filters/BUILD.bazel
@@ -2,13 +2,19 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")

 go_library(
    name = "go_default_library",
-    srcs = ["filter.go"],
+    srcs = [
+        "errors.go",
+        "filter.go",
+    ],
    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filters",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//tools:__subpackages__",
    ],
-    deps = ["//consensus-types/primitives:go_default_library"],
+    deps = [
+        "//consensus-types/primitives:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
 )

 go_test(
@@ -18,5 +24,6 @@ go_test(
    deps = [
        "//consensus-types/primitives:go_default_library",
        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
    ],
 )
--- a/beacon-chain/db/filters/errors.go
+++ b/beacon-chain/db/filters/errors.go
@@ -0,0 +1,9 @@
+package filters
+
+import "errors"
+
+var (
+	ErrIncompatibleFilters = errors.New("combination of filters is not valid")
+	ErrNotSet              = errors.New("filter was not set")
+	ErrInvalidQuery        = errors.New("invalid query")
+)
--- a/beacon-chain/db/filters/filter.go
+++ b/beacon-chain/db/filters/filter.go
@@ -14,7 +14,10 @@
 //	}
 package filters

-import primitives "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+)

 // FilterType defines an enum which is used as the keys in a map that tracks
 // set attribute filters for data as part of the `FilterQuery` struct type.
@@ -45,10 +48,34 @@ const (
 	SlotStep
 )

+// SlotRoot is the slot and root of a single block.
+type SlotRoot struct {
+	Slot primitives.Slot
+	Root [32]byte
+}
+
+// AncestryQuery is a special query that describes a chain of blocks that satisfies the invariant of:
+// blocks[n].parent_root == blocks[n-1].root.
+type AncestryQuery struct {
+	// Slot of oldest to return.
+	Earliest primitives.Slot
+	// Descendent that all ancestors in chain must descend from.
+	Descendent SlotRoot
+	set        bool
+}
+
+func (aq AncestryQuery) Span() primitives.Slot {
+	if aq.Earliest > aq.Descendent.Slot {
+		return 0
+	}
+	return (aq.Descendent.Slot - aq.Earliest) + 1 // +1 to include upper bound
+}
+
 // QueryFilter defines a generic interface for type-asserting
 // specific filters to use in querying DB objects.
 type QueryFilter struct {
-	queries map[FilterType]interface{}
+	queries  map[FilterType]interface{}
+	ancestry AncestryQuery
 }

 // NewFilter instantiates a new QueryFilter type used to build filters for
@@ -132,3 +159,42 @@ func (q *QueryFilter) SetSlotStep(val uint64) *QueryFilter {
 	q.queries[SlotStep] = val
 	return q
 }
+
+// SimpleSlotRange returns the start and end slot of a query filter if it is a simple slot range query.
+// A simple slot range query is one where the filter only contains a start slot and an end slot.
+// If the query is not a simple slot range query, the bool return value will be false.
+func (q *QueryFilter) SimpleSlotRange() (primitives.Slot, primitives.Slot, bool) {
+	if len(q.queries) != 2 || q.queries[StartSlot] == nil || q.queries[EndSlot] == nil {
+		return 0, 0, false
+	}
+	start, ok := q.queries[StartSlot].(primitives.Slot)
+	if !ok {
+		return 0, 0, false
+	}
+	end, ok := q.queries[EndSlot].(primitives.Slot)
+	if !ok {
+		return 0, 0, false
+	}
+	return start, end, true
+}
+
+// SetAncestryQuery sets the filter to be an ancestryQuery. Note that this filter type is exclusive with
+// other filters, so call ing GetAncestryQuery will return an error if other values are set.
+func (q *QueryFilter) SetAncestryQuery(aq AncestryQuery) *QueryFilter {
+	aq.set = true
+	q.ancestry = aq
+	return q
+}
+
+func (q *QueryFilter) GetAncestryQuery() (AncestryQuery, error) {
+	if !q.ancestry.set {
+		return q.ancestry, ErrNotSet
+	}
+	if len(q.queries) > 0 {
+		return q.ancestry, errors.Wrap(ErrIncompatibleFilters, "AncestryQuery cannot be combined with other filters")
+	}
+	if q.ancestry.Earliest > q.ancestry.Descendent.Slot {
+		return q.ancestry, errors.Wrap(ErrInvalidQuery, "descendent slot must come after earliest slot")
+	}
+	return q.ancestry, nil
+}
--- a/beacon-chain/db/filters/filter_test.go
+++ b/beacon-chain/db/filters/filter_test.go
@@ -5,6 +5,7 @@ import (

 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )

 func TestQueryFilter_ChainsCorrectly(t *testing.T) {
@@ -28,3 +29,64 @@ func TestQueryFilter_ChainsCorrectly(t *testing.T) {
 		}
 	}
 }
+
+func TestSimpleSlotRange(t *testing.T) {
+	type tc struct {
+		name        string
+		applFilters []func(*QueryFilter) *QueryFilter
+		isSimple    bool
+		start       primitives.Slot
+		end         primitives.Slot
+	}
+	cases := []tc{
+		{
+			name:        "no filters",
+			applFilters: []func(*QueryFilter) *QueryFilter{},
+			isSimple:    false,
+		},
+		{
+			name: "start slot",
+			applFilters: []func(*QueryFilter) *QueryFilter{
+				func(f *QueryFilter) *QueryFilter {
+					return f.SetStartSlot(3)
+				},
+			},
+			isSimple: false,
+		},
+		{
+			name: "end slot",
+			applFilters: []func(*QueryFilter) *QueryFilter{
+				func(f *QueryFilter) *QueryFilter {
+					return f.SetEndSlot(3)
+				},
+			},
+			isSimple: false,
+		},
+		{
+			name: "end slot",
+			applFilters: []func(*QueryFilter) *QueryFilter{
+				func(f *QueryFilter) *QueryFilter {
+					return f.SetStartSlot(3)
+				},
+				func(f *QueryFilter) *QueryFilter {
+					return f.SetEndSlot(7)
+				},
+			},
+			start:    3,
+			end:      7,
+			isSimple: true,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			f := NewFilter()
+			for _, filt := range c.applFilters {
+				f = filt(f)
+			}
+			start, end, isSimple := f.SimpleSlotRange()
+			require.Equal(t, c.isSimple, isSimple)
+			require.Equal(t, c.start, start)
+			require.Equal(t, c.end, end)
+		})
+	}
+}
--- a/beacon-chain/db/kv/archived_point.go
+++ b/beacon-chain/db/kv/archived_point.go
@@ -35,7 +35,7 @@ func (s *Store) LastArchivedRoot(ctx context.Context) [32]byte {
 		_, blockRoot = bkt.Cursor().Last()
 		return nil
 	}); err != nil { // This view never returns an error, but we'll handle anyway for sanity.
-		panic(err)
+		panic(err) // lint:nopanic -- View never returns an error.
 	}

 	return bytesutil.ToBytes32(blockRoot)
@@ -53,7 +53,7 @@ func (s *Store) ArchivedPointRoot(ctx context.Context, slot primitives.Slot) [32
 		blockRoot = bucket.Get(bytesutil.SlotToBytesBigEndian(slot))
 		return nil
 	}); err != nil { // This view never returns an error, but we'll handle anyway for sanity.
-		panic(err)
+		panic(err) // lint:nopanic -- View never returns an error.
 	}

 	return bytesutil.ToBytes32(blockRoot)
@@ -69,7 +69,7 @@ func (s *Store) HasArchivedPoint(ctx context.Context, slot primitives.Slot) bool
 		exists = iBucket.Get(bytesutil.SlotToBytesBigEndian(slot)) != nil
 		return nil
 	}); err != nil { // This view never returns an error, but we'll handle anyway for sanity.
-		panic(err)
+		panic(err) // lint:nopanic -- View never returns an error.
 	}
 	return exists
 }
--- a/beacon-chain/db/kv/blocks.go
+++ b/beacon-chain/db/kv/blocks.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"slices"

 	"github.com/ethereum/go-ethereum/common"
 	"github.com/golang/snappy"
@@ -117,13 +118,95 @@ func (s *Store) HeadBlock(ctx context.Context) (interfaces.ReadOnlySignedBeaconB
 	return headBlock, err
 }

+// blocksAncestryQuery returns all blocks *before* the descendent block;
+// that is: inclusive of q.Earliest, exclusive of q.Descendent.Slot.
+func (s *Store) blocksAncestryQuery(ctx context.Context, q filters.AncestryQuery) ([]interfaces.ReadOnlySignedBeaconBlock, [][32]byte, error) {
+	// Save resources if no blocks will be found by the query.
+	if q.Span() < 1 {
+		return nil, nil, filters.ErrInvalidQuery
+	}
+
+	blocks := make([]interfaces.ReadOnlySignedBeaconBlock, 0, q.Span())
+	roots := make([][32]byte, 0, q.Span())
+	// Handle edge case where start and end are equal; slotRootsInRange would see end < start and err.
+	// So, just grab the descendent in its own tx and stop there.
+	if q.Span() == 1 {
+		err := s.db.View(func(tx *bolt.Tx) error {
+			descendent, err := s.getBlock(ctx, q.Descendent.Root, tx)
+			if err != nil {
+				return errors.Wrap(err, "descendent block not in db")
+			}
+			blocks = append(blocks, descendent)
+			roots = append(roots, q.Descendent.Root)
+			return nil
+		})
+		return blocks, roots, err
+	}
+
+	// stop before the descendent slot since it is determined by the query
+	sr, err := s.slotRootsInRange(ctx, q.Earliest, q.Descendent.Slot-1, -1)
+	if err != nil {
+		return nil, nil, err
+	}
+	err = s.db.View(func(tx *bolt.Tx) error {
+		descendent, err := s.getBlock(ctx, q.Descendent.Root, tx)
+		if err != nil {
+			return errors.Wrap(err, "descendent block not in db")
+		}
+		proot := descendent.Block().ParentRoot()
+		lowest := descendent.Block().Slot()
+		blocks = append(blocks, descendent)
+		roots = append(roots, q.Descendent.Root)
+		// slotRootsInRange returns the roots in descending order
+		for _, prev := range sr {
+			if prev.slot < q.Earliest {
+				return nil
+			}
+			if prev.slot >= lowest {
+				continue
+			}
+			if prev.root == proot {
+				p, err := s.getBlock(ctx, prev.root, tx)
+				if err != nil {
+					return err
+				}
+				roots = append(roots, prev.root)
+				blocks = append(blocks, p)
+				proot = p.Block().ParentRoot()
+				lowest = p.Block().Slot()
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, nil, err
+	}
+	slices.Reverse(roots)
+	slices.Reverse(blocks)
+
+	return blocks, roots, err
+}
+
 // Blocks retrieves a list of beacon blocks and its respective roots by filter criteria.
 func (s *Store) Blocks(ctx context.Context, f *filters.QueryFilter) ([]interfaces.ReadOnlySignedBeaconBlock, [][32]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.Blocks")
 	defer span.End()
+
+	if q, err := f.GetAncestryQuery(); err == nil {
+		return s.blocksAncestryQuery(ctx, q)
+	} else {
+		if !errors.Is(err, filters.ErrNotSet) {
+			return nil, nil, err
+		}
+	}
+
 	blocks := make([]interfaces.ReadOnlySignedBeaconBlock, 0)
 	blockRoots := make([][32]byte, 0)

+	if start, end, isSimple := f.SimpleSlotRange(); isSimple {
+		return s.blocksForSlotRange(ctx, start, end)
+	}
+
 	err := s.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(blocksBucket)

@@ -146,6 +229,69 @@ func (s *Store) Blocks(ctx context.Context, f *filters.QueryFilter) ([]interface
 	return blocks, blockRoots, err
 }

+// cleanupMissingBlockIndices cleans up the slot->root mapping, and the parent root index pointing
+// from each of these blocks to each of their children. Since we don't have the blocks themselves,
+// we don't know their parent root to efficiently clean the index going the other direction.
+func (s *Store) cleanupMissingBlockIndices(ctx context.Context, badBlocks []slotRoot) {
+	errs := make([]error, 0)
+	err := s.db.Update(func(tx *bolt.Tx) error {
+		for _, sr := range badBlocks {
+			log.WithField("root", fmt.Sprintf("%#x", sr.root)).WithField("slot", sr.slot).Warn("Cleaning up indices for missing block")
+			if err := s.deleteSlotIndexEntry(tx, sr.slot, sr.root); err != nil {
+				errs = append(errs, errors.Wrapf(err, "failed to clean up slot index entry for root %#x and slot %d", sr.root, sr.slot))
+			}
+			if err := tx.Bucket(blockParentRootIndicesBucket).Delete(sr.root[:]); err != nil {
+				errs = append(errs, errors.Wrapf(err, "failed to clean up block parent index for root %#x", sr.root))
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		errs = append(errs, err)
+	}
+	for _, err := range errs {
+		log.WithError(err).Error("Failed to clean up indices for missing block")
+	}
+}
+
+// blocksForSlotRange gets all blocks and roots for a given slot range.
+// This function uses the slot->root index, which can contain multiple entries for the same slot
+// in case of forks. It will return all blocks for the given slot range, and the roots of those blocks.
+// The [i]th element of the blocks slice corresponds to the [i]th element of the roots slice.
+// If a block is not found, it will be added to a slice of missing blocks, which will have their indices cleaned
+// in a separate Update transaction before the method returns. This is done to compensate for a previous bug where
+// block deletions left danging index entries.
+func (s *Store) blocksForSlotRange(ctx context.Context, startSlot, endSlot primitives.Slot) ([]interfaces.ReadOnlySignedBeaconBlock, [][32]byte, error) {
+	slotRootPairs, err := s.slotRootsInRange(ctx, startSlot, endSlot, -1) // set batch size to zero to retrieve all
+	if err != nil {
+		return nil, nil, err
+	}
+	slices.Reverse(slotRootPairs)
+	badBlocks := make([]slotRoot, 0)
+	defer func() { s.cleanupMissingBlockIndices(ctx, badBlocks) }()
+	roots := make([][32]byte, 0, len(slotRootPairs))
+	blks := make([]interfaces.ReadOnlySignedBeaconBlock, 0, len(slotRootPairs))
+	err = s.db.View(func(tx *bolt.Tx) error {
+		for _, sr := range slotRootPairs {
+			blk, err := s.getBlock(ctx, sr.root, tx)
+			if err != nil {
+				if errors.Is(err, ErrNotFound) {
+					badBlocks = append(badBlocks, sr)
+					continue
+				}
+				return err
+			}
+			roots = append(roots, sr.root)
+			blks = append(blks, blk)
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, nil, err
+	}
+	return blks, roots, nil
+}
+
 // BlockRoots retrieves a list of beacon block roots by filter criteria. If the caller
 // requires both the blocks and the block roots for a certain filter they should instead
 // use the Blocks function rather than use BlockRoots. During periods of non finality
@@ -185,7 +331,7 @@ func (s *Store) HasBlock(ctx context.Context, blockRoot [32]byte) bool {
 		exists = bkt.Get(blockRoot[:]) != nil
 		return nil
 	}); err != nil { // This view never returns an error, but we'll handle anyway for sanity.
-		panic(err)
+		panic(err) // lint:nopanic -- View never returns an error.
 	}
 	return exists
 }
@@ -720,6 +866,7 @@ type slotRoot struct {
 }

 // slotRootsInRange returns slot and block root pairs of length min(batchSize, end-slot)
+// If batchSize < 0, the limit check will be skipped entirely.
 func (s *Store) slotRootsInRange(ctx context.Context, start, end primitives.Slot, batchSize int) ([]slotRoot, error) {
 	_, span := trace.StartSpan(ctx, "BeaconDB.slotRootsInRange")
 	defer span.End()
@@ -729,10 +876,26 @@ func (s *Store) slotRootsInRange(ctx context.Context, start, end primitives.Slot

 	var pairs []slotRoot
 	key := bytesutil.SlotToBytesBigEndian(end)
+
+	edge := false // used to detect whether we are at the very beginning or end of the index
 	err := s.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(blockSlotIndicesBucket)
 		c := bkt.Cursor()
-		for k, v := c.Seek(key); k != nil; k, v = c.Prev() {
+		for k, v := c.Seek(key); ; /* rely on internal checks to exit */ k, v = c.Prev() {
+			if len(k) == 0 && len(v) == 0 {
+				// The `edge`` variable and this `if` deal with 2 edge cases:
+				// - Seeking past the end of the bucket (the `end` param is higher than the highest slot).
+				// - Seeking before the beginning of the bucket (the `start` param is lower than the lowest slot).
+				// In both of these cases k,v will be nil and we can handle the same way using `edge` to
+				// - continue to the next iteration. If the following Prev() key/value is nil, Prev has gone past the beginning.
+				// - Otherwise, iterate as usual.
+				if edge {
+					return nil
+				}
+				edge = true
+				continue
+			}
+			edge = false
 			slot := bytesutil.BytesToSlotBigEndian(k)
 			if slot > end {
 				continue // Seek will seek to the next key *after* the given one if not present
@@ -747,11 +910,13 @@ func (s *Store) slotRootsInRange(ctx context.Context, start, end primitives.Slot
 			for _, r := range roots {
 				pairs = append(pairs, slotRoot{slot: slot, root: r})
 			}
+			if batchSize < 0 {
+				continue
+			}
 			if len(pairs) >= batchSize {
 				return nil // allows code to easily cap the number of items pruned
 			}
 		}
-		return nil
 	})

 	return pairs, err
--- a/beacon-chain/db/kv/blocks_test.go
+++ b/beacon-chain/db/kv/blocks_test.go
@@ -24,9 +24,11 @@ import (
 	"google.golang.org/protobuf/proto"
 )

+type testNewBlockFunc func(primitives.Slot, []byte) (interfaces.ReadOnlySignedBeaconBlock, error)
+
 var blockTests = []struct {
 	name     string
-	newBlock func(primitives.Slot, []byte) (interfaces.ReadOnlySignedBeaconBlock, error)
+	newBlock testNewBlockFunc
 }{
 	{
 		name: "phase0",
@@ -742,6 +744,120 @@ func TestStore_Blocks_FiltersCorrectly(t *testing.T) {
 	}
 }

+func testBlockChain(t *testing.T, nb testNewBlockFunc, slots []primitives.Slot, parent []byte) []interfaces.ReadOnlySignedBeaconBlock {
+	if len(parent) < 32 {
+		var zero [32]byte
+		copy(parent, zero[:])
+	}
+	chain := make([]interfaces.ReadOnlySignedBeaconBlock, 0, len(slots))
+	for _, slot := range slots {
+		pr := make([]byte, 32)
+		copy(pr, parent)
+		b, err := nb(slot, pr)
+		require.NoError(t, err)
+		chain = append(chain, b)
+		npr, err := b.Block().HashTreeRoot()
+		parent = npr[:]
+		require.NoError(t, err)
+	}
+	return chain
+}
+
+func testSlotSlice(start, end primitives.Slot) []primitives.Slot {
+	end += 1 // add 1 to make the range inclusive
+	slots := make([]primitives.Slot, 0, end-start)
+	for ; start < end; start++ {
+		slots = append(slots, start)
+	}
+	return slots
+}
+
+func TestCleanupMissingBlockIndices(t *testing.T) {
+	for _, tt := range blockTests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := context.Background()
+			db := setupDB(t)
+			chain := testBlockChain(t, tt.newBlock, testSlotSlice(1, 10), nil)
+			require.NoError(t, db.SaveBlocks(ctx, chain))
+			corrupt, err := blocks.NewROBlock(chain[5])
+			require.NoError(t, err)
+			cr := corrupt.Root()
+			require.NoError(t, db.db.Update(func(tx *bolt.Tx) error {
+				return tx.Bucket(blocksBucket).Delete(cr[:])
+			}))
+			// Need to also delete it from the cache!!
+			db.blockCache.Del(string(cr[:]))
+			res, roots, err := db.Blocks(ctx, filters.NewFilter().SetEndSlot(10).SetStartSlot(1))
+			require.NoError(t, err)
+			require.Equal(t, 9, len(roots))
+			require.Equal(t, len(res), len(roots))
+			require.NoError(t, db.db.View(func(tx *bolt.Tx) error {
+				encSlot := bytesutil.SlotToBytesBigEndian(corrupt.Block().Slot())
+				// make sure slot->root index is cleaned up
+				require.Equal(t, 0, len(tx.Bucket(blockSlotIndicesBucket).Get(encSlot)))
+				require.Equal(t, 0, len(tx.Bucket(blockParentRootIndicesBucket).Get(cr[:])))
+				return nil
+			}))
+		})
+	}
+}
+
+func TestCleanupMissingForkedBlockIndices(t *testing.T) {
+	for _, tt := range blockTests[0:1] {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := context.Background()
+			db := setupDB(t)
+
+			chain := testBlockChain(t, tt.newBlock, testSlotSlice(1, 10), nil)
+			require.NoError(t, db.SaveBlocks(ctx, chain))
+
+			// forkChain should skip the slot at skipBlock, and have the same parent
+			skipBlockParent := chain[4].Block().ParentRoot()
+			// It should start at the same slot as missingBlock, which comes one slot after the skip slot,
+			// so there are 2 blocks in that slot
+			missingBlock, err := blocks.NewROBlock(chain[5])
+			require.NoError(t, err)
+			// missingBlock will be deleted in the main chain, but there will be a block at that slot in the fork chain
+			forkChain := testBlockChain(t, tt.newBlock, testSlotSlice(missingBlock.Block().Slot(), 10), skipBlockParent[:])
+			require.NoError(t, db.SaveBlocks(ctx, forkChain))
+			forkChainStart, err := blocks.NewROBlock(forkChain[0])
+			require.NoError(t, err)
+
+			encMissingSlot := bytesutil.SlotToBytesBigEndian(missingBlock.Block().Slot())
+			require.NoError(t, db.db.View(func(tx *bolt.Tx) error {
+				require.Equal(t, 32, len(tx.Bucket(blockParentRootIndicesBucket).Get(missingBlock.RootSlice())))
+				// There are 2 block roots packed in this slot, so it is 64 bytes long
+				require.Equal(t, 64, len(tx.Bucket(blockSlotIndicesBucket).Get(encMissingSlot)))
+				// skipBlockParent should also have 2 entries and be 64 bytes, since the forkChain is based on the same parent as the skip block
+				childRoots := tx.Bucket(blockParentRootIndicesBucket).Get(skipBlockParent[:])
+				require.Equal(t, 64, len(childRoots))
+				return nil
+			}))
+
+			require.NoError(t, db.db.Update(func(tx *bolt.Tx) error {
+				return tx.Bucket(blocksBucket).Delete(missingBlock.RootSlice())
+			}))
+			// Need to also delete it from the cache!!
+			db.blockCache.Del(string(missingBlock.RootSlice()))
+
+			// Blocks should give us blocks from all chains.
+			res, roots, err := db.Blocks(ctx, filters.NewFilter().SetEndSlot(10).SetStartSlot(1))
+			require.NoError(t, err)
+			require.Equal(t, (len(chain)-1)+len(forkChain), len(roots))
+			require.Equal(t, len(res), len(roots))
+			require.NoError(t, db.db.View(func(tx *bolt.Tx) error {
+				// There should now be 32 bytes in this index - one root from the forked chain
+				slotIdxVal := tx.Bucket(blockSlotIndicesBucket).Get(encMissingSlot)
+				require.Equal(t, forkChainStart.Root(), [32]byte(slotIdxVal))
+				require.Equal(t, 0, len(tx.Bucket(blockParentRootIndicesBucket).Get(missingBlock.RootSlice())))
+				forkChildRoot := tx.Bucket(blockParentRootIndicesBucket).Get(skipBlockParent[:])
+				require.Equal(t, 64, len(forkChildRoot))
+				return nil
+			}))
+		})
+	}
+}
+
 func TestStore_Blocks_VerifyBlockRoots(t *testing.T) {
 	for _, tt := range blockTests {
 		t.Run(tt.name, func(t *testing.T) {
--- a/beacon-chain/db/kv/deposit_contract.go
+++ b/beacon-chain/db/kv/deposit_contract.go
@@ -20,7 +20,7 @@ func (s *Store) DepositContractAddress(ctx context.Context) ([]byte, error) {
 		addr = chainInfo.Get(depositContractAddressKey)
 		return nil
 	}); err != nil { // This view never returns an error, but we'll handle anyway for sanity.
-		panic(err)
+		panic(err) // lint:nopanic -- View never returns an error.
 	}
 	return addr, nil
 }
--- a/beacon-chain/db/kv/state.go
+++ b/beacon-chain/db/kv/state.go
@@ -407,7 +407,7 @@ func (s *Store) HasState(ctx context.Context, blockRoot [32]byte) bool {
 		return nil
 	})
 	if err != nil {
-		panic(err)
+		panic(err) // lint:nopanic -- View never returns an error.
 	}
 	return hasState
 }
--- a/beacon-chain/db/slasherkv/slasher_test.go
+++ b/beacon-chain/db/slasherkv/slasher_test.go
@@ -587,7 +587,7 @@ func BenchmarkHighestAttestations(b *testing.B) {
 	beaconDB := setupDB(b)
 	require.NoError(b, beaconDB.SaveAttestationRecordsForValidators(ctx, atts))

-	allIndices := make([]primitives.ValidatorIndex, valsPerAtt*count)
+	allIndices := make([]primitives.ValidatorIndex, 0, valsPerAtt*count)
 	for i := 0; i < count; i++ {
 		indicesForAtt := make([]primitives.ValidatorIndex, valsPerAtt)
 		for r := 0; r < valsPerAtt; r++ {
--- a/beacon-chain/execution/block_cache.go
+++ b/beacon-chain/execution/block_cache.go
@@ -158,7 +158,7 @@ func trim(queue *cache.FIFO, maxSize uint64) {
 	for s := uint64(len(queue.ListKeys())); s > maxSize; s-- {
 		// #nosec G104 popProcessNoopFunc never returns an error
 		if _, err := queue.Pop(popProcessNoopFunc); err != nil { // This never returns an error, but we'll handle anyway for sanity.
-			panic(err)
+			panic(err) // lint:nopanic -- popProcessNoopFunc never returns an error.
 		}
 	}
 }
--- a/beacon-chain/execution/testing/mock_faulty_powchain.go
+++ b/beacon-chain/execution/testing/mock_faulty_powchain.go
@@ -57,7 +57,7 @@ func (*FaultyExecutionChain) ChainStartEth1Data() *ethpb.Eth1Data {
 func (*FaultyExecutionChain) PreGenesisState() state.BeaconState {
 	s, err := state_native.InitializeFromProtoUnsafePhase0(&ethpb.BeaconState{})
 	if err != nil {
-		panic("could not initialize state")
+		panic("could not initialize state") // lint:nopanic -- test code.
 	}
 	return s
 }
--- a/beacon-chain/node/BUILD.bazel
+++ b/beacon-chain/node/BUILD.bazel
@@ -61,7 +61,6 @@ go_library(
        "//monitoring/prometheus:go_default_library",
        "//monitoring/tracing:go_default_library",
        "//runtime:go_default_library",
-        "//runtime/debug:go_default_library",
        "//runtime/prereqs:go_default_library",
        "//runtime/version:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
--- a/beacon-chain/node/node.go
+++ b/beacon-chain/node/node.go
@@ -64,7 +64,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/prometheus"
 	"github.com/prysmaticlabs/prysm/v5/runtime"
-	"github.com/prysmaticlabs/prysm/v5/runtime/debug"
 	"github.com/prysmaticlabs/prysm/v5/runtime/prereqs"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/sirupsen/logrus"
@@ -432,7 +431,6 @@ func (b *BeaconNode) Start() {
 		defer signal.Stop(sigc)
 		<-sigc
 		log.Info("Got interrupt, shutting down...")
-		debug.Exit(b.cliCtx) // Ensure trace and CPU profile data are flushed.
 		go b.Close()
 		for i := 10; i > 0; i-- {
 			<-sigc
@@ -440,7 +438,7 @@ func (b *BeaconNode) Start() {
 				log.WithField("times", i-1).Info("Already shutting down, interrupt more to panic")
 			}
 		}
-		panic("Panic closing the beacon node")
+		panic("Panic closing the beacon node") // lint:nopanic -- Panic is requested by user.
 	}()

 	// Wait for stop channel to be closed.
@@ -706,7 +704,7 @@ func (b *BeaconNode) registerP2P(cliCtx *cli.Context) error {
 func (b *BeaconNode) fetchP2P() p2p.P2P {
 	var p *p2p.Service
 	if err := b.services.FetchService(&p); err != nil {
-		panic(err)
+		panic(err) // lint:nopanic -- This could panic application start if the services are misconfigured.
 	}
 	return p
 }
@@ -714,7 +712,7 @@ func (b *BeaconNode) fetchP2P() p2p.P2P {
 func (b *BeaconNode) fetchBuilderService() *builder.Service {
 	var s *builder.Service
 	if err := b.services.FetchService(&s); err != nil {
-		panic(err)
+		panic(err) // lint:nopanic -- This could panic application start if the services are misconfigured.
 	}
 	return s
 }
@@ -1018,13 +1016,13 @@ func (b *BeaconNode) registerPrometheusService(_ *cli.Context) error {
 	var additionalHandlers []prometheus.Handler
 	var p *p2p.Service
 	if err := b.services.FetchService(&p); err != nil {
-		panic(err)
+		panic(err) // lint:nopanic -- This could panic application start if the services are misconfigured.
 	}
 	additionalHandlers = append(additionalHandlers, prometheus.Handler{Path: "/p2p", Handler: p.InfoHandler})

 	var c *blockchain.Service
 	if err := b.services.FetchService(&c); err != nil {
-		panic(err)
+		panic(err) // lint:nopanic -- This could panic application start if the services are misconfigured.
 	}

 	service := prometheus.NewService(
--- a/beacon-chain/operations/attestations/kv/aggregated.go
+++ b/beacon-chain/operations/attestations/kv/aggregated.go
@@ -23,10 +23,7 @@ import (
 func (c *AttCaches) AggregateUnaggregatedAttestations(ctx context.Context) error {
 	ctx, span := trace.StartSpan(ctx, "operations.attestations.kv.AggregateUnaggregatedAttestations")
 	defer span.End()
-	unaggregatedAtts, err := c.UnaggregatedAttestations()
-	if err != nil {
-		return err
-	}
+	unaggregatedAtts := c.UnaggregatedAttestations()
 	return c.aggregateUnaggregatedAtts(ctx, unaggregatedAtts)
 }

--- a/beacon-chain/operations/attestations/kv/unaggregated.go
+++ b/beacon-chain/operations/attestations/kv/unaggregated.go
@@ -53,7 +53,7 @@ func (c *AttCaches) SaveUnaggregatedAttestations(atts []ethpb.Att) error {
 }

 // UnaggregatedAttestations returns all the unaggregated attestations in cache.
-func (c *AttCaches) UnaggregatedAttestations() ([]ethpb.Att, error) {
+func (c *AttCaches) UnaggregatedAttestations() []ethpb.Att {
 	c.unAggregateAttLock.RLock()
 	defer c.unAggregateAttLock.RUnlock()
 	unAggregatedAtts := c.unAggregatedAtt
@@ -68,7 +68,7 @@ func (c *AttCaches) UnaggregatedAttestations() ([]ethpb.Att, error) {
 			atts = append(atts, att.Clone())
 		}
 	}
-	return atts, nil
+	return atts
 }

 // UnaggregatedAttestationsBySlotIndex returns the unaggregated attestations in cache,
--- a/beacon-chain/operations/attestations/kv/unaggregated_test.go
+++ b/beacon-chain/operations/attestations/kv/unaggregated_test.go
@@ -29,8 +29,7 @@ func TestKV_Unaggregated_UnaggregatedAttestations(t *testing.T) {
 		// cache a bitlist whose length is different from the attestation bitlist's length
 		cache.seenAtt.Set(id.String(), []bitfield.Bitlist{{0b1001}}, c.DefaultExpiration)

-		atts, err := cache.UnaggregatedAttestations()
-		require.NoError(t, err)
+		atts := cache.UnaggregatedAttestations()
 		assert.Equal(t, 0, len(atts))
 	})
 }
@@ -169,8 +168,7 @@ func TestKV_Unaggregated_DeleteUnaggregatedAttestation(t *testing.T) {
 		for _, att := range atts {
 			assert.NoError(t, cache.DeleteUnaggregatedAttestation(att))
 		}
-		returned, err := cache.UnaggregatedAttestations()
-		require.NoError(t, err)
+		returned := cache.UnaggregatedAttestations()
 		assert.DeepEqual(t, []ethpb.Att{}, returned)
 	})

@@ -234,11 +232,10 @@ func TestKV_Unaggregated_DeleteSeenUnaggregatedAttestations(t *testing.T) {
 		assert.NoError(t, err)
 		assert.Equal(t, 1, count)
 		assert.Equal(t, 2, cache.UnaggregatedAttestationCount())
-		returned, err := cache.UnaggregatedAttestations()
+		returned := cache.UnaggregatedAttestations()
 		sort.Slice(returned, func(i, j int) bool {
 			return bytes.Compare(returned[i].GetAggregationBits(), returned[j].GetAggregationBits()) < 0
 		})
-		require.NoError(t, err)
 		assert.DeepEqual(t, []ethpb.Att{atts[0], atts[2]}, returned)
 	})

@@ -261,8 +258,7 @@ func TestKV_Unaggregated_DeleteSeenUnaggregatedAttestations(t *testing.T) {
 		assert.NoError(t, err)
 		assert.Equal(t, 3, count)
 		assert.Equal(t, 0, cache.UnaggregatedAttestationCount())
-		returned, err := cache.UnaggregatedAttestations()
-		require.NoError(t, err)
+		returned := cache.UnaggregatedAttestations()
 		assert.DeepEqual(t, []ethpb.Att{}, returned)
 	})

--- a/beacon-chain/operations/attestations/mock/mock.go
+++ b/beacon-chain/operations/attestations/mock/mock.go
@@ -1,3 +1,4 @@
+// lint:nopanic -- Mock / test code, panic is allowed.
 package mock

 import (
@@ -79,8 +80,8 @@ func (m *PoolMock) SaveUnaggregatedAttestations(atts []ethpb.Att) error {
 }

 // UnaggregatedAttestations --
-func (m *PoolMock) UnaggregatedAttestations() ([]ethpb.Att, error) {
-	return m.UnaggregatedAtts, nil
+func (m *PoolMock) UnaggregatedAttestations() []ethpb.Att {
+	return m.UnaggregatedAtts
 }

 // UnaggregatedAttestationsBySlotIndex --
--- a/beacon-chain/operations/attestations/pool.go
+++ b/beacon-chain/operations/attestations/pool.go
@@ -26,7 +26,7 @@ type Pool interface {
 	// For unaggregated attestations.
 	SaveUnaggregatedAttestation(att ethpb.Att) error
 	SaveUnaggregatedAttestations(atts []ethpb.Att) error
-	UnaggregatedAttestations() ([]ethpb.Att, error)
+	UnaggregatedAttestations() []ethpb.Att
 	UnaggregatedAttestationsBySlotIndex(ctx context.Context, slot primitives.Slot, committeeIndex primitives.CommitteeIndex) []*ethpb.Attestation
 	UnaggregatedAttestationsBySlotIndexElectra(ctx context.Context, slot primitives.Slot, committeeIndex primitives.CommitteeIndex) []*ethpb.AttestationElectra
 	DeleteUnaggregatedAttestation(att ethpb.Att) error
--- a/beacon-chain/operations/attestations/prune_expired.go
+++ b/beacon-chain/operations/attestations/prune_expired.go
@@ -61,12 +61,8 @@ func (s *Service) pruneExpiredAtts() {
 	if _, err := s.cfg.Pool.DeleteSeenUnaggregatedAttestations(); err != nil {
 		log.WithError(err).Error("Cannot delete seen attestations")
 	}
-	unAggregatedAtts, err := s.cfg.Pool.UnaggregatedAttestations()
-	if err != nil {
-		log.WithError(err).Error("Could not get unaggregated attestations")
-		return
-	}
-	for _, att := range unAggregatedAtts {
+
+	for _, att := range s.cfg.Pool.UnaggregatedAttestations() {
 		if s.expired(att.GetData().Slot) {
 			if err := s.cfg.Pool.DeleteUnaggregatedAttestation(att); err != nil {
 				log.WithError(err).Error("Could not delete expired unaggregated attestation")
--- a/beacon-chain/operations/attestations/prune_expired_test.go
+++ b/beacon-chain/operations/attestations/prune_expired_test.go
@@ -54,9 +54,7 @@ func TestPruneExpired_Ticker(t *testing.T) {

 	done := make(chan struct{}, 1)
 	async.RunEvery(ctx, 500*time.Millisecond, func() {
-		atts, err := s.cfg.Pool.UnaggregatedAttestations()
-		require.NoError(t, err)
-		for _, attestation := range atts {
+		for _, attestation := range s.cfg.Pool.UnaggregatedAttestations() {
 			if attestation.GetData().Slot == 0 {
 				return
 			}
--- a/beacon-chain/operations/blstoexec/mock/mock.go
+++ b/beacon-chain/operations/blstoexec/mock/mock.go
@@ -28,10 +28,10 @@ func (m *PoolMock) InsertBLSToExecChange(change *eth.SignedBLSToExecutionChange)

 // MarkIncluded --
 func (*PoolMock) MarkIncluded(_ *eth.SignedBLSToExecutionChange) {
-	panic("implement me")
+	panic("implement me") // lint:nopanic -- mock / test code.
 }

 // ValidatorExists --
 func (*PoolMock) ValidatorExists(_ primitives.ValidatorIndex) bool {
-	panic("implement me")
+	panic("implement me") // lint:nopanic -- mock / test code.
 }
--- a/beacon-chain/operations/slashings/mock/mock.go
+++ b/beacon-chain/operations/slashings/mock/mock.go
@@ -40,10 +40,10 @@ func (*PoolMock) ConvertToElectra() {}

 // MarkIncludedAttesterSlashing --
 func (*PoolMock) MarkIncludedAttesterSlashing(_ ethpb.AttSlashing) {
-	panic("implement me")
+	panic("implement me") // lint:nopanic -- Test / mock code.
 }

 // MarkIncludedProposerSlashing --
 func (*PoolMock) MarkIncludedProposerSlashing(_ *ethpb.ProposerSlashing) {
-	panic("implement me")
+	panic("implement me") // lint:nopanic -- Test / mock code.
 }
--- a/beacon-chain/operations/voluntaryexits/mock/mock.go
+++ b/beacon-chain/operations/voluntaryexits/mock/mock.go
@@ -28,5 +28,5 @@ func (m *PoolMock) InsertVoluntaryExit(exit *eth.SignedVoluntaryExit) {

 // MarkIncluded --
 func (*PoolMock) MarkIncluded(_ *eth.SignedVoluntaryExit) {
-	panic("implement me")
+	panic("implement me") // lint:nopanic -- Mock / test code.
 }
--- a/beacon-chain/p2p/encoder/ssz.go
+++ b/beacon-chain/p2p/encoder/ssz.go
@@ -15,9 +15,8 @@ import (

 var _ NetworkEncoding = (*SszNetworkEncoder)(nil)

-// MaxGossipSize allowed for gossip messages.
-var MaxGossipSize = params.BeaconConfig().GossipMaxSize // 10 Mib.
-var MaxChunkSize = params.BeaconConfig().MaxChunkSize   // 10 Mib.
+// MaxPayloadSize allowed for gossip and rpc messages.
+var MaxPayloadSize = params.BeaconConfig().MaxPayloadSize // 10 Mib.

 // This pool defines the sync pool for our buffered snappy writers, so that they
 // can be constantly reused.
@@ -43,8 +42,8 @@ func (_ SszNetworkEncoder) EncodeGossip(w io.Writer, msg fastssz.Marshaler) (int
 	if err != nil {
 		return 0, err
 	}
-	if uint64(len(b)) > MaxGossipSize {
-		return 0, errors.Errorf("gossip message exceeds max gossip size: %d bytes > %d bytes", len(b), MaxGossipSize)
+	if uint64(len(b)) > MaxPayloadSize {
+		return 0, errors.Errorf("gossip message exceeds max gossip size: %d bytes > %d bytes", len(b), MaxPayloadSize)
 	}
 	b = snappy.Encode(nil /*dst*/, b)
 	return w.Write(b)
@@ -60,11 +59,11 @@ func (_ SszNetworkEncoder) EncodeWithMaxLength(w io.Writer, msg fastssz.Marshale
 	if err != nil {
 		return 0, err
 	}
-	if uint64(len(b)) > MaxChunkSize {
+	if uint64(len(b)) > MaxPayloadSize {
 		return 0, fmt.Errorf(
 			"size of encoded message is %d which is larger than the provided max limit of %d",
 			len(b),
-			MaxChunkSize,
+			MaxPayloadSize,
 		)
 	}
 	// write varint first
@@ -81,7 +80,10 @@ func doDecode(b []byte, to fastssz.Unmarshaler) error {

 // DecodeGossip decodes the bytes to the protobuf gossip message provided.
 func (_ SszNetworkEncoder) DecodeGossip(b []byte, to fastssz.Unmarshaler) error {
-	b, err := DecodeSnappy(b, MaxGossipSize)
+	if uint64(len(b)) > MaxCompressedLen(MaxPayloadSize) {
+		return fmt.Errorf("gossip message exceeds maximum compressed limit: %d", MaxCompressedLen(MaxPayloadSize))
+	}
+	b, err := DecodeSnappy(b, MaxPayloadSize)
 	if err != nil {
 		return err
 	}
@@ -111,11 +113,11 @@ func (e SszNetworkEncoder) DecodeWithMaxLength(r io.Reader, to fastssz.Unmarshal
 	if err != nil {
 		return err
 	}
-	if msgLen > MaxChunkSize {
+	if msgLen > MaxPayloadSize {
 		return fmt.Errorf(
 			"remaining bytes %d goes over the provided max limit of %d",
 			msgLen,
-			MaxChunkSize,
+			MaxPayloadSize,
 		)
 	}
 	msgMax, err := e.MaxLength(msgLen)
@@ -156,6 +158,18 @@ func (_ SszNetworkEncoder) MaxLength(length uint64) (int, error) {
 	return maxLen, nil
 }

+// MaxCompressedLen returns the maximum compressed size for a given payload size.
+//
+// Spec pseudocode definition:
+// def max_compressed_len(n: uint64) -> uint64:
+//
+//	# Worst-case compressed length for a given payload of size n when using snappy:
+//	# https://github.com/google/snappy/blob/32ded457c0b1fe78ceb8397632c416568d6714a0/snappy.cc#L218C1-L218C47
+//	return uint64(32 + n + n / 6)
+func MaxCompressedLen(n uint64) uint64 {
+	return 32 + n + n/6
+}
+
 // Writes a bytes value through a snappy buffered writer.
 func writeSnappyBuffer(w io.Writer, b []byte) (int, error) {
 	bufWriter := newBufferedWriter(w)
--- a/beacon-chain/p2p/encoder/ssz_test.go
+++ b/beacon-chain/p2p/encoder/ssz_test.go
@@ -555,11 +555,19 @@ func TestSszNetworkEncoder_FailsSnappyLength(t *testing.T) {
 	e := &encoder.SszNetworkEncoder{}
 	att := &ethpb.Fork{}
 	data := make([]byte, 32)
-	binary.PutUvarint(data, encoder.MaxGossipSize+32)
+	binary.PutUvarint(data, encoder.MaxPayloadSize+1)
 	err := e.DecodeGossip(data, att)
 	require.ErrorContains(t, "snappy message exceeds max size", err)
 }

+func TestSszNetworkEncoder_ExceedsMaxCompressedLimit(t *testing.T) {
+	e := &encoder.SszNetworkEncoder{}
+	att := &ethpb.Fork{}
+	data := make([]byte, encoder.MaxCompressedLen(encoder.MaxPayloadSize)+1)
+	err := e.DecodeGossip(data, att)
+	require.ErrorContains(t, "gossip message exceeds maximum compressed limit", err)
+}
+
 func testRoundTripWithLength(t *testing.T, e *encoder.SszNetworkEncoder) {
 	buf := new(bytes.Buffer)
 	msg := &ethpb.Fork{
@@ -604,31 +612,28 @@ func TestSszNetworkEncoder_EncodeWithMaxLength(t *testing.T) {
 	e := &encoder.SszNetworkEncoder{}
 	params.SetupTestConfigCleanup(t)
 	c := params.BeaconNetworkConfig()
-	encoder.MaxChunkSize = uint64(5)
+	encoder.MaxPayloadSize = uint64(5)
 	params.OverrideBeaconNetworkConfig(c)
 	_, err := e.EncodeWithMaxLength(buf, msg)
-	wanted := fmt.Sprintf("which is larger than the provided max limit of %d", encoder.MaxChunkSize)
+	wanted := fmt.Sprintf("which is larger than the provided max limit of %d", encoder.MaxPayloadSize)
 	assert.ErrorContains(t, wanted, err)
 }

 func TestSszNetworkEncoder_DecodeWithMaxLength(t *testing.T) {
 	buf := new(bytes.Buffer)
-	msg := &ethpb.Fork{
-		PreviousVersion: []byte("fooo"),
-		CurrentVersion:  []byte("barr"),
-		Epoch:           4242,
-	}
 	e := &encoder.SszNetworkEncoder{}
 	params.SetupTestConfigCleanup(t)
 	c := params.BeaconNetworkConfig()
-	maxChunkSize := uint64(5)
-	encoder.MaxChunkSize = maxChunkSize
-	params.OverrideBeaconNetworkConfig(c)
-	_, err := e.EncodeGossip(buf, msg)
+	maxPayloadSize := uint64(5)
+	encoder.MaxPayloadSize = maxPayloadSize
+	_, err := buf.Write(gogo.EncodeVarint(maxPayloadSize + 1))
 	require.NoError(t, err)
+	_, err = buf.Write(make([]byte, maxPayloadSize+1))
+	require.NoError(t, err)
+	params.OverrideBeaconNetworkConfig(c)
 	decoded := &ethpb.Fork{}
 	err = e.DecodeWithMaxLength(buf, decoded)
-	wanted := fmt.Sprintf("goes over the provided max limit of %d", maxChunkSize)
+	wanted := fmt.Sprintf("goes over the provided max limit of %d", maxPayloadSize)
 	assert.ErrorContains(t, wanted, err)
 }

@@ -639,8 +644,8 @@ func TestSszNetworkEncoder_DecodeWithMultipleFrames(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	c := params.BeaconNetworkConfig()
 	// 4 * 1 Mib
-	maxChunkSize := uint64(1 << 22)
-	encoder.MaxChunkSize = maxChunkSize
+	maxPayloadSize := uint64(1 << 22)
+	encoder.MaxPayloadSize = maxPayloadSize
 	params.OverrideBeaconNetworkConfig(c)
 	_, err := e.EncodeWithMaxLength(buf, st.ToProtoUnsafe().(*ethpb.BeaconState))
 	require.NoError(t, err)
--- a/beacon-chain/p2p/message_id.go
+++ b/beacon-chain/p2p/message_id.go
@@ -50,7 +50,7 @@ func MsgID(genesisValidatorsRoot []byte, pmsg *pubsubpb.Message) string {
 	if fEpoch >= params.BeaconConfig().AltairForkEpoch {
 		return postAltairMsgID(pmsg, fEpoch)
 	}
-	decodedData, err := encoder.DecodeSnappy(pmsg.Data, params.BeaconConfig().GossipMaxSize)
+	decodedData, err := encoder.DecodeSnappy(pmsg.Data, params.BeaconConfig().MaxPayloadSize)
 	if err != nil {
 		combinedData := append(params.BeaconConfig().MessageDomainInvalidSnappy[:], pmsg.Data...)
 		h := hash.Hash(combinedData)
@@ -77,10 +77,9 @@ func postAltairMsgID(pmsg *pubsubpb.Message, fEpoch primitives.Epoch) string {
 	topicLen := len(topic)
 	topicLenBytes := bytesutil.Uint64ToBytesLittleEndian(uint64(topicLen)) // topicLen cannot be negative

-	// beyond Bellatrix epoch, allow 10 Mib gossip data size
-	gossipPubSubSize := params.BeaconConfig().GossipMaxSize
+	gossipPayloadSize := params.BeaconConfig().MaxPayloadSize

-	decodedData, err := encoder.DecodeSnappy(pmsg.Data, gossipPubSubSize)
+	decodedData, err := encoder.DecodeSnappy(pmsg.Data, gossipPayloadSize)
 	if err != nil {
 		totalLength, err := math.AddInt(
 			len(params.BeaconConfig().MessageDomainInvalidSnappy),
@@ -95,7 +94,7 @@ func postAltairMsgID(pmsg *pubsubpb.Message, fEpoch primitives.Epoch) string {
 			copy(msg, "invalid")
 			return bytesutil.UnsafeCastToString(msg)
 		}
-		if uint64(totalLength) > gossipPubSubSize {
+		if uint64(totalLength) > gossipPayloadSize {
 			// this should never happen
 			msg := make([]byte, 20)
 			copy(msg, "invalid")
--- a/beacon-chain/p2p/pubsub.go
+++ b/beacon-chain/p2p/pubsub.go
@@ -11,9 +11,11 @@ import (
 	pubsubpb "github.com/libp2p/go-libp2p-pubsub/pb"
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/encoder"
 	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	mathutil "github.com/prysmaticlabs/prysm/v5/math"
 	pbrpc "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 )

@@ -141,7 +143,7 @@ func (s *Service) pubsubOptions() []pubsub.Option {
 		}),
 		pubsub.WithSubscriptionFilter(s),
 		pubsub.WithPeerOutboundQueueSize(int(s.cfg.QueueSize)),
-		pubsub.WithMaxMessageSize(int(params.BeaconConfig().GossipMaxSize)),
+		pubsub.WithMaxMessageSize(int(MaxMessageSize())), // lint:ignore uintcast -- Max Message Size is a config value and is naturally bounded by networking limitations.
 		pubsub.WithValidateQueueSize(int(s.cfg.QueueSize)),
 		pubsub.WithPeerScore(peerScoringParams()),
 		pubsub.WithPeerScoreInspect(s.peerInspector, time.Minute),
@@ -235,3 +237,14 @@ func ExtractGossipDigest(topic string) ([4]byte, error) {
 	}
 	return bytesutil.ToBytes4(digest), nil
 }
+
+// MaxMessageSize returns the maximum allowed compressed message size.
+//
+// Spec pseudocode definition:
+// def max_message_size() -> uint64:
+//
+//	# Allow 1024 bytes for framing and encoding overhead but at least 1MiB in case MAX_PAYLOAD_SIZE is small.
+//	return max(max_compressed_len(MAX_PAYLOAD_SIZE) + 1024, 1024 * 1024)
+func MaxMessageSize() uint64 {
+	return mathutil.Max(encoder.MaxCompressedLen(params.BeaconConfig().MaxPayloadSize)+1024, 1024*1024)
+}
--- a/beacon-chain/p2p/types/BUILD.bazel
+++ b/beacon-chain/p2p/types/BUILD.bazel
@@ -17,6 +17,7 @@ go_library(
        "//validator/client:__pkg__",
    ],
    deps = [
+        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
--- a/beacon-chain/p2p/types/types.go
+++ b/beacon-chain/p2p/types/types.go
@@ -9,12 +9,11 @@ import (

 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 )

-const rootLength = 32
-
 const maxErrorLength = 256

 // SSZBytes is a bytes slice that satisfies the fast-ssz interface.
@@ -34,7 +33,7 @@ func (b *SSZBytes) HashTreeRootWith(hh *ssz.Hasher) error {
 }

 // BeaconBlockByRootsReq specifies the block by roots request type.
-type BeaconBlockByRootsReq [][rootLength]byte
+type BeaconBlockByRootsReq [][fieldparams.RootLength]byte

 // MarshalSSZTo marshals the block by roots request with the provided byte slice.
 func (r *BeaconBlockByRootsReq) MarshalSSZTo(dst []byte) ([]byte, error) {
@@ -59,25 +58,25 @@ func (r *BeaconBlockByRootsReq) MarshalSSZ() ([]byte, error) {

 // SizeSSZ returns the size of the serialized representation.
 func (r *BeaconBlockByRootsReq) SizeSSZ() int {
-	return len(*r) * rootLength
+	return len(*r) * fieldparams.RootLength
 }

 // UnmarshalSSZ unmarshals the provided bytes buffer into the
 // block by roots request object.
 func (r *BeaconBlockByRootsReq) UnmarshalSSZ(buf []byte) error {
 	bufLen := len(buf)
-	maxLength := int(params.BeaconConfig().MaxRequestBlocks * rootLength)
+	maxLength := int(params.BeaconConfig().MaxRequestBlocks * fieldparams.RootLength)
 	if bufLen > maxLength {
 		return errors.Errorf("expected buffer with length of up to %d but received length %d", maxLength, bufLen)
 	}
-	if bufLen%rootLength != 0 {
+	if bufLen%fieldparams.RootLength != 0 {
 		return ssz.ErrIncorrectByteSize
 	}
-	numOfRoots := bufLen / rootLength
-	roots := make([][rootLength]byte, 0, numOfRoots)
+	numOfRoots := bufLen / fieldparams.RootLength
+	roots := make([][fieldparams.RootLength]byte, 0, numOfRoots)
 	for i := 0; i < numOfRoots; i++ {
-		var rt [rootLength]byte
-		copy(rt[:], buf[i*rootLength:(i+1)*rootLength])
+		var rt [fieldparams.RootLength]byte
+		copy(rt[:], buf[i*fieldparams.RootLength:(i+1)*fieldparams.RootLength])
 		roots = append(roots, rt)
 	}
 	*r = roots
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
james-prysm	9470fc6e95	fixing beacon	2025-04-03 16:15:56 -05:00
james-prysm	e88b611aeb	fixing grpc issue	2025-04-03 15:26:29 -05:00
james-prysm	6168cdc135	merging apiutil and httputil	2025-04-03 15:20:04 -05:00
james-prysm	3cbdb2f333	Merge branch 'develop' into migrate-json-rest-handler	2025-04-03 15:17:55 -05:00
james-prysm	fe2fd9fe67	wip	2025-04-03 15:14:14 -05:00
james-prysm	6c1f064ac1	init	2025-04-03 14:49:50 -05:00
james-prysm	4a1c627f6f	migrates some helper functions from beacon API to apiutil (#15125 ) * migration and changelog * missed valid root * removing unneeded test, more optimization * adding strict dependency * linting * fixing 1 more test * bastin's suggestion	2025-04-03 19:48:26 +00:00
Nishant Das	0c2464c497	Handle Consolidation Processing Edge Case (#15122 ) * Clean it up * Add regression test case * changelog	2025-04-03 16:07:33 +00:00
james-prysm	2cfc204e9a	removed redundant mock validator and replaced with test util one (#15111 )	2025-04-02 21:17:20 +00:00
Nishant Das	877d9ee948	Revert Execution Requests in E2E (#15119 ) * Revert "Disable Execution Request Testing On Mainnet (#15115)" This reverts commit `70c31949ba`. * Revert "Trigger Execution Requests In E2E (#14971)" This reverts commit `e38fdb09a4`. * Changelog	2025-04-02 16:12:35 +00:00
Kaloyan Tanev	785fefa3f1	Do not cache slot committee aggregations for DVs (#15110 ) * Do not cache slot committee for DV agggregations * Add changelog --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-04-02 15:54:47 +00:00
kevincatty	0c22d91a55	fix: remove duplicate WithBlobStorage in options initialization (#15036 ) Signed-off-by: kevincatty <zhanshanmao@outlook.com> Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-04-02 15:25:00 +00:00
NikolaiKryshnev	fb60456116	Improved README structure and visual presentation (#14860 ) Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-04-02 15:23:10 +00:00
jinjiadu	be56711892	fix: fix slice init length (#14407 ) Signed-off-by: jinjiadu <jinjiadu@aliyun.com> Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-04-02 15:21:26 +00:00
kasey	96f1ebf706	more efficient ancestry db queries, stategen (#15063 ) Co-authored-by: Kasey <kasey@users.noreply.github.com>	2025-04-01 20:16:58 +00:00
John	bdb12c7d2f	fix: use io.ReadFull instead of stream.Read (#15089 )	2025-04-01 19:23:04 +00:00
LesCyber	83cf0f8658	refactor: use errors.New to replace fmt.Errorf with no parameters (#15007 ) Signed-off-by: LesCyber <andi4cing@gmail.com>	2025-04-01 19:03:16 +00:00
VolodymyrBg	762594a368	feat(proposer): add gas limit range warnings (#15078 ) * feat(proposer): add gas limit range warnings * Update config/proposer/loader/loader.go Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com> * Update config/proposer/loader/loader.go Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com> * Create volodymyrbg_gas_limit_warnings.md --------- Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com>	2025-04-01 19:00:21 +00:00
kilavvy	c1fc812a38	Fix typos in test code (#14991 ) * Update keymanager_test.go * Update fork_test.go * Update README.md * Update README.md	2025-04-01 18:31:59 +00:00
riyueguang	340935af9c	refactor: use the built-in min to simplify the code (#15091 ) Signed-off-by: riyueguang <rustruby@outlook.com>	2025-04-01 17:57:22 +00:00
kasey	17d0082c5c	cleanup block indices for missing blocks (#15040 ) Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>	2025-04-01 17:54:35 +00:00
terence	e998b5ec97	Use latest state to pack attestation (#15113 ) * Use latest state to pack attestation * Add a test to make sure it would have failed when using head state instead of latest state	2025-04-01 15:31:45 +00:00
james-prysm	5d0eb3168c	small optimization (#15116 )	2025-04-01 14:55:29 +00:00
terence	e0c2aa71d4	Update spec tests to beta 4 (#15114 ) * Update spec tests to beta 4 * Change log to ignored	2025-04-01 14:32:57 +00:00
Nishant Das	70c31949ba	Disable Execution Request Testing On Mainnet (#15115 ) * DisableOnMainnet * Changelog	2025-04-01 10:38:05 +00:00
Nishant Das	e38fdb09a4	Trigger Execution Requests In E2E (#14971 ) * Trigger Consolidation * Finally have it working * Fix Build * Revert Change * Fix Context * Finally have consolidations working * Get Evaluator Working * Get Withdrawals Working * Changelog * Finally Passes * New line * Try again * fmt * fmt * Fix Test	2025-04-01 06:49:51 +00:00
james-prysm	a50e981c74	removing redundant loop in computeOnChainAggregate (#15108 ) * removing redundant loop * Update beacon-chain/rpc/prysm/v1alpha1/validator/proposer_attestations_electra.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * removing unused import * replacing with more used function * resolving Unsafe cast from uint64 to int error --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-03-31 21:22:47 +00:00
Bastin	8be205cf3d	Use fieldparams.RootLength instead of local variable in p2p types.go (#15106 ) * use fieldparams.RootLength instead of local var * gazelle fix	2025-03-31 12:42:07 +00:00
kasey	1b65e00096	refactor state-by-root test to table-driven (#15087 ) Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>	2025-03-28 23:34:34 +00:00
james-prysm	e3fb4e86ec	validator client initialization cleanup (#15080 ) * cleanup * fixing optimal sort order for struct * reverting clictx change based on kasey's feedback * adding in fix for old trace file flag * more cleanup for clarity * optimizing if statement check and fixing wallet open on web enable * optimizing if statement check and fixing wallet open on web enable * some more cleanup and bug fix on open wallet * reverting debug.go changes will handle in a separate PR * removing useless comment * changing useWeb to enableAPI * fixing tests and linting * manu feedback and one optimization removing auth token check * gaz	2025-03-28 14:03:42 +00:00
terence	70aaad1904	Add more tests to process pending deposits (#15099 )	2025-03-27 14:16:41 +00:00
Radosław Kapka	e42611ec72	Allow hex strings in `/eth/v1/beacon/states/{state_id}/root` endpoint (#15098 ) * Allow hex strings in `/eth/v1/beacon/states/{state_id}/root` endpoint * changelog <3 * remove redundant conversion * use `bytesutil.IsHex`	2025-03-27 14:13:57 +00:00
Bastin	a3e61275a3	Add light client types to spectest (#15097 ) * add light client types to spectest * changelog entry * remove lightclientSnapshot from tests	2025-03-26 17:44:30 +00:00
terence	e82f9ccca3	Proposer: change attestation sorting to reward numerator (#15093 ) * Change proposer block's sorting algo to proposer reward numerator * Feedback * Comments * Add a cache for attestation reward numerator	2025-03-26 16:21:41 +00:00
Bastin	38a6a7a4ea	Add SSZ support for light client updates by range API (#15082 ) * create ssz payload * remove unused function * remove access to state * gazelle fix * fix ssz size for electra finality update * fix fork digest version problem * fix chunk size * fix fork version * fix fork version * add tests * add changelog entry * add PR link in changelog entry * fix lint error * Update beacon-chain/rpc/eth/light-client/handlers.go Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com> * check for context error * send response in chunks * remove content disposition header --------- Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>	2025-03-26 15:06:03 +00:00
Bastin	1295c987e8	Remove content disposition header from `httputil.WriteSSZ` (#15092 ) * remove content disposition header from httputil.WriteSSZ * fix changelog * fix newly added calls to WriteSSZ	2025-03-26 14:17:19 +00:00
Radosław Kapka	6a27c41aad	Implement validator identities Beacon API endpoint (#15086 ) * implementation * tests * changelog <3 * linter fix * test fix	2025-03-25 16:49:35 +00:00
Radosław Kapka	98b13ea144	Update changelog for v5.3.2 release (#15096 ) * Changelog for v5.3.2 * add header section * fragment file	2025-03-25 16:38:29 +00:00
james-prysm	c735ed2e32	Remove use of committee list from validator client (#15039 ) * wip * fixing unit tests * changing is aggregator function * wip * fully removing the use of committee from validator client, adding a wrapper type for duties * fixing tests * fixing linting * fixing more tests * changelog * adding some more tests * Update proto/prysm/v1alpha1/validator.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> * radek's feedback * removing accidently checked in --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-03-25 16:25:42 +00:00
Potuz	bd17779231	Use headstate to validate canonical attestations for old targets (#15095 ) * Use headstate to validate canonical attestations for old targets * Update beacon-chain/blockchain/process_attestation_helpers.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-03-25 13:36:47 +00:00
james-prysm	e08ed0d823	Deprecate broken and unused debug flags in favor of --pprof (#15083 ) * deprecating the trace and cpuprofile flags in favor of pprof * gaz * fixing change log title * added hidden tags	2025-03-24 19:30:32 +00:00
xinhangzhou	2b4d8a09ff	refactor: use maps.Copy for cleaner map handling (#15090 ) Signed-off-by: xinhangzhou <shuangcui@aliyun.com>	2025-03-24 19:23:10 +00:00
Potuz	21e1f7883b	Add feature flag to blacklist blocks (#15030 ) * Add feature flag to blacklist blocks * review and add tests * add test * review * Kasey's review --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-03-21 22:20:39 +00:00
Julian Yap	bfa24606c3	refactor: Remove redundant string conversion in BeaconDbStater.State (#15081 )	2025-03-21 16:23:16 +00:00
Potuz	d7628bab37	Fix genesis block proposal (#15084 ) * Fix genesis block proposal * fix test * fix test 2	2025-03-21 15:34:22 +00:00
Radosław Kapka	8e2c9313e9	Save orphaned Electra attestations properly (#15060 ) * Deal with block attestations post_electra * changelog <3 * Revert "Deal with block attestations post_electra" This reverts commit 3d9a40a5a8369e863c37cebec0a53f4bbcf79fe2.	2025-03-21 12:54:19 +00:00
terence	fea441d889	Clean up batch process new pending deposits (#15085 )	2025-03-21 05:45:52 +00:00
Radosław Kapka	2351064e8d	Improve blobs Beacon API endpoint (#14845 ) * Improve blobs API endpoint * changelog <3 * use summary * Kasey's review * one more	2025-03-20 19:06:37 +00:00
Manu NALEPA	d2699761ed	`subscribeToSubnets`: Remove unused parameter. (#15079 ) * `subscribeToSubnets`: Remove unused parameter. * Changelog: Change `Fixed` to `Ignored`.	2025-03-20 15:57:55 +00:00
Manu NALEPA	c73473b59d	Tracked validator cache: Make sure no to loose the reference. (#15077 )	2025-03-20 10:00:40 +00:00
Preston Van Loon	2aa52fb56a	Add static analyzer to discourage use of panic() (#15075 ) * Implement static analysis to prevent panics * Add nopanic to nogo * Fix violations and add exclusions Fix violations and add exclusions for all * Changelog fragment * Use pass.Report instead of pass.Reportf * Remove strings.ToLower for checking init method name * Add exclusion for herumi init * Move api/client/beacon template function to init and its own file * Fix nopanic testcase	2025-03-19 18:04:15 +00:00
Preston Van Loon	16d5abd21b	Update changelog for v5.3.1 release (#15045 ) * Update changelog for v5.3.1 release. * Add description for v5.3.1 * Changelog fragment	2025-03-19 15:10:30 +00:00
james-prysm	08bfaca42d	panic to error changes and changelog (#15074 )	2025-03-19 14:31:29 +00:00
Sam Calder-Mason	179cedd4a0	feat(event-stream): Support block_gossip topic (#15038 ) * feat(event-stream): Add block_gossip topic support * feat(event-stream): Add block_gossip topic support * feat(event-stream): Add block_gossip topic support * feat: add block gossip topic support to beacon api event stream * fix: sync_fuzz_test panic * fix: check for nil operationNotifier before sending block gossip The operationNotifier was not being checked for nil before being used, which could lead to a panic if it was not initialized. This commit adds a nil check to prevent the panic. --------- Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>	2025-03-18 19:27:27 +00:00
terence	0f39857653	Clean up infinity signature usages (#15072 )	2025-03-18 19:27:06 +00:00
terence	645328bb9e	Clarify infinity signature deposit tests (#15071 )	2025-03-18 19:25:56 +00:00
james-prysm	9d2273c514	Move prysm specific performance endpoint (#15062 ) * adding in check for non prysm node and moving the prysm endpoint to the prysm beacon client * fixing a bug connecting to a non prysm client and moving the prysm api call to the prysm beacon client * changelog * fixing linting * Update validator/client/metrics.go Co-authored-by: Radosław Kapka <rkapka@wp.pl> --------- Co-authored-by: Radosław Kapka <rkapka@wp.pl>	2025-03-18 15:02:54 +00:00
Radosław Kapka	34429368fe	Update seen unaggregated att cache to Electra (#15034 ) * Update seen unaggregated att cache to Electra * changelog <3 * pass full att * revert extracting length check * check if 1 bit set * test fix * adding end to end unit test saving unaggregated electra att and then verifying that it's already seen in the cache * Terence's feedback * return false on errors --------- Co-authored-by: james-prysm <james@prysmaticlabs.com>	2025-03-17 16:34:34 +00:00
Nishant Das	629568c796	Handle Networking Message Limits Better (#14799 ) * Handle Message Limits * Changelog * Ignore them for now * Sort fields * Update to Latest Versions	2025-03-17 14:15:20 +00:00
terence	5c24978702	Add hoodi testnet flag (#15057 ) * Add hoodi testnet flag * Add upstream test * Fix test	2025-03-17 05:49:27 +00:00
kasey	4e44999207	OCL forked changed-files pin; pin others (#15056 ) * OCL forked changed-files pin; pin others * changelog :) --------- Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>	2025-03-15 19:56:25 +00:00
james-prysm	15ae71c0da	Builder ssz (#14976 ) * wip * refactoring functions for easier readability * allow ssz for register validator * changelog * adding in blinded block submission tests * adding in tests for header ssz * fixing linting and tests * adding in custom errors and fixing ssz validator registration * Update api/client/builder/client.go Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com> * Update api/client/builder/client.go Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com> * manu's feedback * linting * adding in info log to notify that this setting was turned on * fixing linting * manu's feedback * fixing import --------- Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com>	2025-03-14 17:23:00 +00:00
terence	1caea86152	Update spec test to v1.5.0-beta.3 (#15050 )	2025-03-14 10:47:16 +00:00
james-prysm	7cef3b0491	adding omitempty to request object (#15031 )	2025-03-11 13:43:00 +00:00
Radosław Kapka	15462844f9	Remove error from signatures of `UnaggregatedAttestations` and `pruneAttsFromPool` (#15028 )	2025-03-10 22:28:51 +00:00