refactor to match updated design

WIP: changes for 3531
get rid of double referencing in error types
2026-01-11 06:18:05 -05:00 · 2023-11-02 13:32:55 -05:00 · 2023-11-01 13:13:11 -05:00 · 2023-10-30 09:15:51 -05:00 · 2023-10-27 17:32:09 -05:00 · 2023-10-27 17:22:16 -05:00
2709 changed files with 77391 additions and 75782 deletions
--- a/.bazelrc
+++ b/.bazelrc
@@ -27,7 +27,6 @@ build:minimal --@io_bazel_rules_go//go/config:tags=minimal
 # Release flags
 build:release --compilation_mode=opt
 build:release --stamp
-build:release --define pgo_enabled=1

 # Build binary with cgo symbolizer for debugging / profiling.
 build:cgo_symbolizer --copt=-g
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-7.0.0
+6.3.2
--- a/.buildkite-bazelrc
+++ b/.buildkite-bazelrc
@@ -9,8 +9,8 @@
 #build:remote-cache --strategy=Genrule=standalone

 # Prysm specific remote-cache properties.
-build:remote-cache --remote_download_minimal
-build:remote-cache --remote_build_event_upload=minimal
+#build:remote-cache --disk_cache=
+build:remote-cache --remote_download_toplevel
 build:remote-cache --remote_cache=grpc://bazel-remote-cache:9092
 # Does not work with rules_oci. See https://github.com/bazel-contrib/rules_oci/issues/292
 #build:remote-cache --experimental_remote_downloader=grpc://bazel-remote-cache:9092
@@ -29,10 +29,7 @@ build --experimental_use_hermetic_linux_sandbox
 # Import workspace options.
 import %workspace%/.bazelrc

-# Enable blake3 once it is supported in remote cache. See: https://github.com/buchgr/bazel-remote/issues/710
-# startup --digest_function=blake3
-
-startup --host_jvm_args=-Xmx8g --host_jvm_args=-Xms4g
+startup --host_jvm_args=-Xmx4g --host_jvm_args=-Xms2g
 build --experimental_strict_action_env
 build --sandbox_tmpfs_path=/tmp
 build --verbose_failures
@@ -42,7 +39,6 @@ build --curses=no --color=no
 build --keep_going
 build --test_output=errors
 build --flaky_test_attempts=5
-build --build_runfile_links=false # Only build runfile symlink forest when required by local action, test, or run command.
 # Disabled race detection due to unstable test results under constrained environment build kite
 # build --features=race

--- a/.deepsource.toml
+++ b/.deepsource.toml
@@ -11,7 +11,7 @@ name = "go"
 enabled = true

 [analyzers.meta]
-import_paths = ["github.com/prysmaticlabs/prysm/v5"]
+import_paths = ["github.com/prysmaticlabs/prysm/v4"]

 [[analyzers]]
 name = "test-coverage"
--- a/.github/actions/gomodtidy/Dockerfile
+++ b/.github/actions/gomodtidy/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.21-alpine
+FROM golang:alpine

 COPY entrypoint.sh /entrypoint.sh

--- a/.github/workflows/fuzz.yml
+++ b/.github/workflows/fuzz.yml
@@ -16,7 +16,7 @@ jobs:
      - uses: actions/checkout@v3
      - uses: actions/setup-go@v4
        with:
-          go-version: '1.21.5'
+          go-version: '1.20'
      - id: list
        uses: shogo82148/actions-go-fuzz/list@v0
        with:
@@ -36,7 +36,7 @@ jobs:
      - uses: actions/checkout@v3
      - uses: actions/setup-go@v4
        with:
-          go-version: '1.21.5'
+          go-version: '1.20'
      - uses: shogo82148/actions-go-fuzz/run@v0
        with:
          packages: ${{ matrix.package }}
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -5,8 +5,6 @@ on:
    branches: [ master ]
  pull_request:
    branches: [ '*' ]
-  merge_group:
-    types: [checks_requested]

 jobs:
  formatting:
@@ -28,15 +26,15 @@ jobs:
    steps:
      - name: Checkout
        uses: actions/checkout@v2
-      - name: Set up Go 1.21
+      - name: Set up Go 1.20
        uses: actions/setup-go@v3
        with:
-          go-version: '1.21.5'
+          go-version: '1.20'
      - name: Run Gosec Security Scanner
        run: | # https://github.com/securego/gosec/issues/469
          export PATH=$PATH:$(go env GOPATH)/bin
          go install github.com/securego/gosec/v2/cmd/gosec@v2.15.0
-          gosec -exclude-generated -exclude=G307 -exclude-dir=crypto/bls/herumi ./...
+          gosec -exclude=G307 -exclude-dir=crypto/bls/herumi ./...

  lint:
    name: Lint
@@ -45,16 +43,16 @@ jobs:
      - name: Checkout
        uses: actions/checkout@v2

-      - name: Set up Go 1.21
+      - name: Set up Go 1.20
        uses: actions/setup-go@v3
        with:
-          go-version: '1.21.5'
+          go-version: '1.20'
          id: go

      - name: Golangci-lint
        uses: golangci/golangci-lint-action@v3
        with:
-          version: v1.55.2
+          version: v1.52.2
          args: --config=.golangci.yml --out-${NO_FUTURE}format colored-line-number

  build:
@@ -64,7 +62,7 @@ jobs:
      - name: Set up Go 1.x
        uses: actions/setup-go@v2
        with:
-          go-version: '1.21.5'
+          go-version: '1.20'
        id: go

      - name: Check out code into the Go module directory
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -6,82 +6,21 @@ run:
    - proto
    - tools/analyzers
  timeout: 10m
-  go: '1.21.5'
+  go: '1.19'

 linters:
-  enable-all: true
-  disable:
-    # Deprecated linters:
-    - deadcode
-    - exhaustivestruct
-    - golint
-    - govet
-    - ifshort
-    - interfacer
-    - maligned
-    - nosnakecase
-    - scopelint
-    - structcheck
-    - varcheck
-
-    # Disabled for now:
-    - asasalint
-    - bodyclose
-    - containedctx
-    - contextcheck
-    - cyclop
-    - depguard
-    - dogsled
-    - dupl
-    - durationcheck
-    - errorlint
-    - exhaustive
-    - exhaustruct
-    - forbidigo
-    - forcetypeassert
-    - funlen
-    - gci
-    - gochecknoglobals
-    - gochecknoinits
-    - goconst
-    - gocritic
-    - gocyclo
-    - godot
-    - godox
-    - goerr113
-    - gofumpt
-    - gomnd
-    - gomoddirectives
-    - inamedparam
-    - interfacebloat
-    - ireturn
-    - lll
-    - maintidx
-    - makezero
-    - musttag
-    - nakedret
-    - nestif
-    - nilnil
-    - nlreturn
-    - noctx
-    - nolintlint
-    - nonamedreturns
-    - nosprintfhostport
-    - perfsprint
-    - prealloc
-    - predeclared
-    - promlinter
-    - protogetter
-    - revive
-    - staticcheck
-    - stylecheck
-    - tagalign
-    - tagliatelle
-    - thelper
-    - unparam
-    - varnamelen
-    - wrapcheck
-    - wsl
+  disable-all: true
+  enable:
+    - gofmt
+    - goimports
+    - unused
+    - errcheck
+    - gosimple
+    - gocognit
+    - dupword
+    - nilerr
+    - whitespace
+    - misspell

 linters-settings:
  gocognit:
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -4,7 +4,6 @@ load("@com_github_atlassian_bazel_tools//goimports:def.bzl", "goimports")
 load("@io_kubernetes_build//defs:run_in_workspace.bzl", "workspace_binary")
 load("@io_bazel_rules_go//go:def.bzl", "nogo")
 load("@bazel_skylib//rules:common_settings.bzl", "string_setting")
-load("@prysm//tools/nogo_config:def.bzl", "nogo_config_exclude")

 prefix = "github.com/prysmaticlabs/prysm"

@@ -12,7 +11,7 @@ exports_files([
    "LICENSE.md",
 ])

-# gazelle:prefix github.com/prysmaticlabs/prysm/v5
+# gazelle:prefix github.com/prysmaticlabs/prysm/v4
 # gazelle:map_kind go_library go_library @prysm//tools/go:def.bzl
 # gazelle:map_kind go_test go_test @prysm//tools/go:def.bzl
 # gazelle:map_kind go_repository go_repository @prysm//tools/go:def.bzl
@@ -83,117 +82,38 @@ workspace_binary(
    cmd = "@com_github_golang_lint//golint",
 )

-STATICCHECK_ANALYZERS = [
-    # Enabled static checks. See https://staticcheck.dev/docs/checks/
-    # Please. keep this list sorted. Don't be a bad person by inserting stuff randomly.
-    "sa1000",
-    "sa1001",
-    "sa1002",
-    "sa1003",
-    "sa1004",
-    "sa1005",
-    "sa1006",
-    "sa1007",
-    "sa1008",
-    "sa1010",
-    "sa1011",
-    "sa1012",
-    "sa1013",
-    "sa1014",
-    "sa1015",
-    "sa1016",
-    "sa1017",
-    "sa1018",
-    # "sa1019", # TODO: Fix all uses of deprecated things.
-    "sa1020",
-    "sa1021",
-    "sa1023",
-    "sa1024",
-    "sa1025",
-    "sa1026",
-    "sa1027",
-    "sa1028",
-    "sa1029",
-    "sa1030",
-    "sa2000",
-    "sa2001",
-    "sa2002",
-    "sa2003",
-    "sa3000",
-    "sa3001",
-    "sa4000",
-    "sa4001",
-    "sa4003",
-    "sa4004",
-    "sa4005",
-    "sa4006",
-    "sa4008",
-    "sa4009",
-    "sa4010",
-    "sa4011",
-    "sa4012",
-    "sa4013",
-    "sa4014",
-    "sa4015",
-    "sa4016",
-    "sa4017",
-    "sa4018",
-    "sa4019",
-    "sa4020",
-    "sa4021",
-    "sa4022",
-    "sa4023",
-    "sa4024",
-    "sa4025",
-    "sa4026",
-    "sa4027",
-    "sa4028",
-    "sa4029",
-    "sa4030",
-    "sa4031",
-    "sa4032",
-    "sa5000",
-    "sa5001",
-    "sa5002",
-    "sa5003",
-    "sa5004",
-    "sa5005",
-    "sa5007",
-    "sa5008",
-    "sa5009",
-    "sa5010",
-    "sa5011",
-    "sa5012",
-    "sa6000",
-    "sa6001",
-    "sa6002",
-    "sa6003",
-    "sa6005",
-    "sa6006",
-    "sa9001",
-    "sa9002",
-    #"sa9003", # Doesn't build. See https://github.com/dominikh/go-tools/pull/1483
-    "sa9004",
-    "sa9005",
-    "sa9006",
-    "sa9007",
-    "sa9008",
-]
-
-nogo_config_exclude(
-    name = "nogo_config_with_excludes",
-    checks = [sa.upper() for sa in STATICCHECK_ANALYZERS],
-    exclude_files = [
-        "external/.*",
-    ],
-    input = "nogo_config.json",
-)
-
 nogo(
    name = "nogo",
-    config = ":nogo_config_with_excludes",
+    config = "nogo_config.json",
    visibility = ["//visibility:public"],
    deps = [
+        "@org_golang_x_tools//go/analysis/passes/unsafeptr:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/unreachable:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/unmarshal:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/tests:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/structtag:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/stdmethods:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/shift:go_default_library",
+        # "@org_golang_x_tools//go/analysis/passes/shadow:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/printf:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/pkgfact:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/nilness:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/nilfunc:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/loopclosure:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/httpresponse:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/findcall:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/deepequalerrors:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/ctrlflow:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/copylock:go_default_library",
+        #  "@org_golang_x_tools//go/analysis/passes/cgocall:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/buildtag:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/buildssa:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/bools:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/atomicalign:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/atomic:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/assign:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/inspect:go_default_library",
+        "@org_golang_x_tools//go/analysis/passes/asmdecl:go_default_library",
        "//tools/analyzers/comparesame:go_default_library",
        "//tools/analyzers/cryptorand:go_default_library",
        "//tools/analyzers/errcheck:go_default_library",
@@ -209,53 +129,6 @@ nogo(
        "//tools/analyzers/shadowpredecl:go_default_library",
        "//tools/analyzers/slicedirect:go_default_library",
        "//tools/analyzers/uintcast:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/appends:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/asmdecl:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/assign:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/atomic:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/atomicalign:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/bools:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/buildssa:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/buildtag:go_default_library",
-        # cgocall disabled
-        #"@org_golang_x_tools//go/analysis/passes/cgocall:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/copylock:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/ctrlflow:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/deepequalerrors:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/defers:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/directive:go_default_library",
-        # fieldalignment disabled
-        #"@org_golang_x_tools//go/analysis/passes/fieldalignment:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/findcall:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/framepointer:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/httpmux:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/httpresponse:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/ifaceassert:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/inspect:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/loopclosure:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/nilfunc:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/nilness:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/pkgfact:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/printf:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/reflectvaluecompare:go_default_library",
-        # shadow disabled
-        #"@org_golang_x_tools//go/analysis/passes/shadow:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/shift:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/sigchanyzer:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/slog:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/sortslice:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/stdmethods:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/stringintconv:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/structtag:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/testinggoroutine:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/tests:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/timeformat:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/unmarshal:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/unreachable:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/unsafeptr:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/unusedresult:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/unusedwrite:go_default_library",
-        "@org_golang_x_tools//go/analysis/passes/usesgenerics:go_default_library",
    ] + select({
        # nogo checks that fail with coverage enabled.
        ":coverage_enabled": [],
@@ -263,7 +136,7 @@ nogo(
            "@org_golang_x_tools//go/analysis/passes/composite:go_default_library",
            "@org_golang_x_tools//go/analysis/passes/lostcancel:go_default_library",
        ],
-    }) + ["@co_honnef_go_tools//staticcheck/%s:go_default_library" % c for c in STATICCHECK_ANALYZERS],
+    }),
 )

 config_setting(
@@ -271,11 +144,6 @@ config_setting(
    values = {"define": "coverage_enabled=1"},
 )

-config_setting(
-    name = "pgo_enabled",
-    values = {"define": "pgo_enabled=1"},
-)
-
 common_files = {
    "//:LICENSE.md": "LICENSE.md",
    "//:README.md": "README.md",
--- a/DEPENDENCIES.md
+++ b/DEPENDENCIES.md
@@ -55,7 +55,7 @@ bazel build //beacon-chain --config=release
 ## Adding / updating dependencies

 1. Add your dependency as you would with go modules. I.e. `go get ...`
-1. Run `bazel run //:gazelle -- update-repos -from_file=go.mod` to update the bazel managed dependencies.
+1. Run `gazelle update-repos -from_file=go.mod` to update the bazel managed dependencies.

 Example:

--- a/INTEROP.md
+++ b/INTEROP.md
@@ -30,6 +30,9 @@ You can use `bazel run //tools/genesis-state-gen` to create a deterministic gene
 - **--output-ssz** string: Output filename of the SSZ marshaling of the generated genesis state
 - **--config-name=interop** string: name of the beacon chain config to use when generating the state. ex mainnet|minimal|interop

+**deprecated flag: use --config-name instead**
+- **--mainnet-config** bool: Select whether genesis state should be generated with mainnet or minimal (default) params
+
 The example below creates 64 validator keys, instantiates a genesis state with those 64 validators and with genesis unix timestamp 1567542540,
 and finally writes a ssz encoded output to ~/Desktop/genesis.ssz. This file can be used to kickstart the beacon chain in the next section. When using the `--interop-*` flags, the beacon node will assume the `interop` config should be used, unless a different config is specified on the command line.

--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -1,6 +0,0 @@
-###############################################################################
-# Bazel now uses Bzlmod by default to manage external dependencies.
-# Please consider migrating your external dependencies from WORKSPACE to MODULE.bazel.
-#
-# For more details, please check https://github.com/bazelbuild/bazel/issues/18958
-###############################################################################
--- a/MODULE.bazel.lock
+++ b/MODULE.bazel.lock
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
 [![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.
+This is the core repository for Prysm, a [Golang](https://golang.org/) implementation of the [Ethereum Consensus](https://ethereum.org/en/eth2/) specification, developed by [Prysmatic Labs](https://prysmaticlabs.com). See the [Changelog](https://github.com/prysmaticlabs/prysm/releases) for details of the latest releases and upcoming breaking changes.

 ### Getting Started

--- a/TERMS_OF_SERVICE.md
+++ b/TERMS_OF_SERVICE.md
@@ -1,53 +1,45 @@
-# Terms of Use
-Effective as of November 2, 2023
+## Terms of Use

-By downloading, accessing or using the Prysm implementation (“Prysm”), you (referenced herein as “you” or the “user”) certify that you have read and agreed to the terms and conditions below (the “Terms”) which form a binding contract between you and Offchain Labs, Inc. (as successor in interest to Prysmatic Labs LLC) (referenced herein as “Offchain Labs”, “we” or “us”). If you do not agree to the Terms, do not download or use Prysm.  Additionally, the Terms of Use available at https://arbitrum.io/tos (or any successor site, the “OCL Terms of Use”) are hereby incorporated by reference into these Terms.  In the event of any conflict between provisions set forth herein and those set forth in the OCL Terms of Use, the provisions set forth herein shall control.
+Effective as of Oct 14, 2020

-## About Prysm
+By downloading, accessing or using the Prysm implementation (“Prysm”), you (referenced herein as “you” or the “user”) certify that you have read and agreed to the terms and conditions below (the “Terms”) which form a binding contract between you and Prysmatic Labs (referenced herein as “we” or “us”). If you do not agree to the Terms, do not download or use Prysm.

-Prysm is a client implementation for the Ethereum blockchain’s consensus protocol. To participate in the network, a user must send ETH from the Ethereum mainnet blockchain to a validator deposit smart contract on Ethereum mainnet. Validators participate in proposing and voting on blocks in the protocol, and the network applies rewards/penalties based on their behavior. A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the official documentation portal, however, we do not warrant the accuracy, completeness or usefulness of this documentation. Any reliance you place on such information is strictly at your own risk.
+### About Prysm
+Prysm is a client implementation for Ethereum consensus protocol for a proof-of-stake blockchain. To participate in the network, a user must send ETH from the Eth1.0 chain into a validator deposit contract, which will queue in the user as a validator in the system. Validators participate in proposing and voting on blocks in the protocol, and the network applies rewards/penalties based on their behavior. A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the official documentation portal, however, we do not warrant the accuracy, completeness or usefulness of this documentation. Any reliance you place on such information is strictly at your own risk.

-## Licensing Terms
-Prysm is an open-source software program licensed pursuant to the GNU General Public License v3.0.
-The Offchain Labs name, the term “Prysm” and all related names, logos, product and service names, designs and slogans are trademarks of Offchain Labs or its affiliates and/or licensors. You must not use such marks without our prior written permission.
-PLEASE READ THESE TERMS CAREFULLY, AS THE OCL TERMS OF USE INCORPORATED BY REFERENCE HEREIN CONTAIN AN AGREEMENT TO ARBITRATE AND OTHER IMPORTANT INFORMATION REGARDING YOUR LEGAL RIGHTS, REMEDIES, AND OBLIGATIONS. THE AGREEMENT TO ARBITRATE REQUIRES (WITH LIMITED EXCEPTION) THAT YOU SUBMIT CLAIMS YOU HAVE AGAINST US TO BINDING AND FINAL ARBITRATION, AND FURTHER (1) YOU WILL ONLY BE PERMITTED TO PURSUE CLAIMS AGAINST OFFCHAIN LABS ON AN INDIVIDUAL BASIS, NOT AS A PLAINTIFF OR CLASS MEMBER IN ANY CLASS OR REPRESENTATIVE ACTION OR PROCEEDING, (2) YOU WILL ONLY BE PERMITTED TO SEEK RELIEF (INCLUDING MONETARY, INJUNCTIVE, AND DECLARATORY RELIEF) ON AN INDIVIDUAL BASIS, AND (3) YOU MAY NOT BE ABLE TO HAVE ANY CLAIMS YOU HAVE AGAINST US RESOLVED BY A JURY OR IN A COURT OF LAW.
+### Licensing Terms
+Prysm is a fully open-source software program licensed pursuant to the GNU General Public License v3.0.

-## Risks of Operating Prysm
+The Prysmatic Labs name, the term “Prysm” and all related names, logos, product and service names, designs and slogans are trademarks of Prysmatic Labs or its affiliates and/or licensors. You must not use such marks without our prior written permission.

-The use of Prysm and acting as a validator on the Ethereum network can lead to loss of money, tokens and value. Ethereum is still an experimental system and ETH remains a risky investment. You alone are responsible for your actions on Prysm, including the security of your ETH and meeting any applicable minimum system requirements.
+### Risks of Operating Prysm
+The use of Prysm and acting as a validator on the Ethereum network can lead to loss of money. Ethereum is still an experimental system and ETH remains a risky investment. You alone are responsible for your actions on Prysm including the security of your ETH and meeting any applicable minimum system requirements.

 Use of Prysm and the ability to receive rewards or penalties may be affected at any time by mistakes made by the user or other users, software problems such as bugs, errors, incorrectly constructed transactions, unsafe cryptographic libraries or malware affecting the network, technical failures in the hardware of a user, security problems experienced by a user and/or actions or inactions of third parties and/or events experienced by third parties, among other risks. We cannot and do not guarantee that any user of Prysm will make money, that the Prysm network will operate in accordance with the documentation or that transactions will be effective or secure.

-YOU ACKNOWLEDGE THAT WE ARE NOT RESPONSIBLE FOR ANY RISKS ASSOCIATED WITH YOUR USE OF PRYSM, AND CANNOT BE HELD LIABLE FOR ANY RESULTING LOSSES THAT YOU EXPERIENCE WHILE ACCESSING OR USING PRYSM.
+We make no claims that Prysm is appropriate or permitted for use in any specific jurisdiction. Access to Prysm may not be legal by certain persons or in certain jurisdictions or countries. If you access Prysm, you do so on your own initiative and are responsible for compliance with local laws.

-BY ACCESSING AND USING PRYSM, YOU REPRESENT AND WARRANT THAT YOU UNDERSTAND THE INHERENT RISKS ASSOCIATED WITH USING CRYPTOGRAPHIC AND BLOCKCHAIN-BASED SYSTEMS, AND THAT YOU HAVE A WORKING KNOWLEDGE OF THE USAGE AND INTRICACIES OF DIGITAL ASSETS, SUCH AS THOSE FOLLOWING THE ETHEREUM TOKEN STANDARD (ERC-20). YOU FURTHER UNDERSTAND THAT THE MARKETS FOR DIGITAL ASSETS ARE HIGHLY VOLATILE DUE TO VARIOUS FACTORS, INCLUDING ADOPTION, SPECULATION, TECHNOLOGY, SECURITY, AND REGULATION. YOU ACKNOWLEDGE AND ACCEPT THAT THE COST AND SPEED OF TRANSACTING WITH CRYPTOGRAPHIC AND BLOCKCHAIN-BASED SYSTEMS SUCH AS ETHEREUM ARE VARIABLE AND MAY INCREASE DRAMATICALLY AT ANY TIME. YOU UNDERSTAND THAT ANYONE CAN CREATE A TOKEN, INCLUDING FAKE VERSIONS OF EXISTING TOKENS AND TOKENS THAT FALSELY CLAIM TO REPRESENT PROJECTS, AND ACKNOWLEDGE AND ACCEPT THE RISK THAT YOU MAY MISTAKENLY INTERACT WITH THOSE OR OTHER TOKENS. YOU FURTHER ACKNOWLEDGE THAT WE ARE NOT RESPONSIBLE FOR ANY OF THE VARIABLES OR RISKS DESCRIBED IN THESE TERMS. YOU UNDERSTAND AND AGREE TO ASSUME FULL RESPONSIBILITY FOR ALL OF THE RISKS OF ACCESSING AND USING PRYSM. YOU ARE SOLELY RESPONSIBLE FOR YOUR WALLETS, FOR SAFEGUARDING THE ASSOCIATED PRIVATE KEY AND FOR ANY ACTIVITY THAT OCCURS USING YOUR WALLET. WITHOUT LIMITING THE FOREGOING, YOU ALSO UNDERSTAND THAT THERE MAY BE TAX AND REGULATORY RISKS RELATED TO USING PRYSM. IT IS YOUR SOLE RESPONSIBILITY TO DETERMINE WHETHER, AND TO WHAT EXTENT, ANY TAXES APPLY TO ANY TRANSACTIONS YOU CONDUCT IN CONNECTION WITH YOUR USE OF PRYSM, AND TO WITHHOLD, COLLECT, REPORT AND REMIT THE CORRECT AMOUNTS OF TAXES TO THE APPROPRIATE TAX AUTHORITIES. DIGITAL ASSETS, BLOCKCHAIN TECHNOLOGY, AND ANY RELATED SOFTWARE AND SERVICES ARE ALSO SUBJECT TO LEGAL AND REGULATORY UNCERTAINTY IN THE UNITED STATES AND OTHER JURISDICTIONS. YOU UNDERSTAND THAT LEGISLATIVE AND REGULATORY CHANGES OR ACTIONS MAY ADVERSELY AFFECT THE USAGE, TRANSFERABILITY, TRANSACTABILITY AND ACCESSIBILITY RELATED TO PRYSM.
+Some Internet plans will charge an additional amount for any excess upload bandwidth used that isn’t included in the plan and may terminate your connection without warning because of overuse. We advise that you check whether your Internet connection is subjected to such limitations and monitor your bandwidth use so that you can stop Prysm before you reach your upload limit.

-We make no claims that Prysm is appropriate or permitted for use in any specific jurisdiction. Access to Prysm may not be legal by certain persons or in certain jurisdictions or countries. If you access Prysm, you do so on your own initiative and are responsible for compliance with all Applicable Law (as defined below), including, without limitation, for the avoidance of doubt, local laws.
+### Warranty Disclaimer
+PRYSM IS PROVIDED ON AN “AS-IS” BASIS AND MAY INCLUDE ERRORS, OMISSIONS, OR OTHER INACCURACIES. PRYSMATIC LABS AND ITS CONTRIBUTORS MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT PRYSM FOR ANY PURPOSE, AND HEREBY EXPRESSLY DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT OR ANY OTHER IMPLIED WARRANTY UNDER THE UNIFORM COMPUTER INFORMATION TRANSACTIONS ACT AS ENACTED BY ANY STATE. WE ALSO MAKE NO REPRESENTATIONS OR WARRANTIES THAT PRYSM WILL OPERATE ERROR-FREE, UNINTERRUPTED, OR IN A MANNER THAT WILL MEET YOUR REQUIREMENTS AND/OR NEEDS. THEREFORE, YOU ASSUME THE ENTIRE RISK REGARDING THE QUALITY AND/OR PERFORMANCE OF PRYSM AND ANY TRANSACTIONS ENTERED INTO THEREON.

-Some Internet plans will charge additional amounts for bandwidth or any excess upload bandwidth used that isn’t included in the plan and may terminate your connection without warning because of overuse. We advise that you check whether your Internet connection is subjected to any such limitations and monitor your bandwidth use and upload volumes.
+### Limitation of Liability
+In no event will Prysmatic Labs or any of its contributors be liable, whether in contract, warranty, tort (including negligence, whether active, passive or imputed), product liability, strict liability or other theory, breach of statutory duty or otherwise arising out of, or in connection with, your use of Prysm, for any direct, indirect, incidental, special or consequential damages (including any loss of profits or data, business interruption or other pecuniary loss, or damage, loss or other compromise of data, in each case whether direct, indirect, incidental, special or consequential) arising out of use Prysm, even if we or other users have been advised of the possibility of such damages. The foregoing limitations and disclaimers shall apply to the maximum extent permitted by applicable law, even if any remedy fails of its essential purpose. You acknowledge and agree that the limitations of liability afforded us hereunder constitute a material and actual inducement and condition to entering into these Terms, and are reasonable, fair and equitable in scope to protect our legitimate interests in light of the fact that we are not receiving consideration from you for providing Prysm.

-## Warranty Disclaimer
+### Indemnification
+To the maximum extent permitted by law, you will defend, indemnify and hold Prysmatic Labs and its contributors harmless from and against any and all claims, actions, suits, investigations, or proceedings by any third party (including any party or purported party to or beneficiary or purported beneficiary of any transaction on Prysm), as well as any and all losses, liabilities,
+damages, costs, and expenses (including reasonable attorneys’ fees) arising out of, accruing from, or in any way related to (i) your breach of the terms of this Agreement, (ii) any transaction, or the failure to occur of any transaction on Prysm, and (iii) your negligence, fraud, or willful misconduct.

-PRYSM IS PROVIDED ON AN “AS-IS” BASIS AND MAY INCLUDE ERRORS, OMISSIONS, OR OTHER INACCURACIES. WITHOUT LIMITING ANYTHING SET FORTH ELSEWHERE IN THESE TERMS, OFFCHAIN LABS AND ITS CONTRIBUTORS MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT PRYSM FOR ANY PURPOSE, AND HEREBY EXPRESSLY DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT OR ANY OTHER IMPLIED WARRANTY UNDER THE UNIFORM COMPUTER INFORMATION TRANSACTIONS ACT AS ENACTED BY ANY STATE OR OTHER GOVERNMENTAL AUTHORITY. WE ALSO MAKE NO REPRESENTATIONS OR WARRANTIES THAT PRYSM WILL OPERATE ERROR-FREE, UNINTERRUPTED, OR IN A MANNER THAT WILL MEET YOUR REQUIREMENTS AND/OR NEEDS. THEREFORE, YOU ASSUME THE ENTIRE RISK REGARDING THE QUALITY AND/OR PERFORMANCE OF PRYSM AND ANY TRANSACTIONS ENTERED INTO THEREON.
+### Compliance with Laws and Tax Obligations
+Your use of Prysm is subject to all applicable laws of any governmental authority, including, without limitation, federal, state and foreign securities laws, tax laws, tariff and trade laws, ordinances, judgments, decrees, injunctions, writs and orders or like actions of any governmental authority and rules, regulations, orders, interpretations, licenses, and permits of any federal,
+regional, state, county, municipal or other governmental authority and you agree to comply with all such laws in your use of Prysm. The users of Prysm are solely responsible to determinate what, if any, taxes apply to their ETH transactions. The owners of, or contributors to, Prysm are not responsible for determining the taxes that apply to ETH transactions.

-## Limitation of Liability
+### Miscellaneous
+These Terms will be construed and enforced in accordance with the laws of the state of Illinois as applied to agreements entered into and completely performed in Illinois. You agree to the personal jurisdiction by and venue in Illinois and waive any objection to such jurisdiction or venue.

-IN NO EVENT WILL OFFCHAIN LABS OR ANY OF ITS AFFILIATES OR ITS OR ANY SUCH AFFILIATE’S DIRECTORS, OFFICERS, EMPLOYEES, AGENTS, OR REPRESENTATIVES OR ANY CONTRIBUTORS (COLLECTIVELY, THE “OCL PARTIES”) BE LIABLE, WHETHER IN CONTRACT, WARRANTY, TORT (INCLUDING NEGLIGENCE, WHETHER ACTIVE, PASSIVE OR IMPUTED), PRODUCT LIABILITY, STRICT LIABILITY OR OTHER THEORY, BREACH OF STATUTORY DUTY OR OTHERWISE ARISING OUT OF, OR IN CONNECTION WITH, YOUR USE OF PRYSM, FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES (INCLUDING ANY LOSS OF PROFITS OR DATA, BUSINESS INTERRUPTION OR OTHER PECUNIARY LOSS, OR DAMAGE, LOSS OR OTHER COMPROMISE OF DATA, IN EACH CASE WHETHER DIRECT, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL) ARISING OUT OF USE PRYSM, EVEN IF WE OR OTHER USERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. The foregoing limitations and disclaimers shall apply to the maximum extent permitted by Applicable Law, even if any remedy fails of its essential purpose. You acknowledge and agree that the limitations of liability afforded us hereunder constitute a material and actual inducement and condition to entering into these Terms, and are reasonable, fair and equitable in scope to protect our legitimate interests in light of the fact that we are not receiving consideration from you for providing Prysm.
+We reserve the right to revise these Terms, and your rights and obligations are at all times subject to the then-current Terms provided on Prysm. Your continued use of Prysm constitutes acceptance of such revised Terms.

-## Indemnification
-
-To the maximum extent permitted by Applicable Law, you will defend, indemnify and hold each OCL Party harmless from and against any and all claims, actions, suits, investigations, or proceedings by any third party (including any party or purported party to or beneficiary or purported beneficiary of any transaction or other activity on Prysm), as well as any and all losses, liabilities, damages, costs, and expenses (including reasonable attorneys’ fees and costs) arising out of, accruing from, or in any way related to (i) your breach of the terms of this Agreement, (ii) any transaction, or the failure to occur of any transaction on Prysm, and (iii) your negligence, fraud, or willful misconduct.
-
-## Compliance with Laws
-
-Your use of Prysm is subject to all applicable laws of any governmental authority, including, without limitation, federal, state and foreign securities laws, tax laws, tariff and trade laws, ordinances, judgments, decrees, injunctions, writs and orders or like actions of any governmental authority and rules, regulations, orders, interpretations, licenses, and permits of any federal, regional, state, county, municipal or other governmental authority (collectively, “Applicable Law”) and you agree to comply with all such Applicable Law in your use of Prysm. The users of Prysm are solely responsible to determinate what, if any, taxes apply to their ETH transactions. The owners of, or contributors to, Prysm are not responsible for determining the taxes that apply to ETH transactions.
-
-## Miscellaneous
-
-These Terms will be governed by the laws of the State of Delaware without regard to its conflict of law provisions. With respect to any disputes or claims not subject to arbitration, as set forth in the OCL Terms of Use, you and Offchain Labs submit to the personal and exclusive jurisdiction of the state and federal courts located within New York, New York and waive any objection to such jurisdiction and venue. The failure of Offchain Labs to exercise or enforce any right or provision of these Terms will not constitute a waiver of such right or provision.
-We reserve the right to revise these Terms, and your rights and obligations are at all times subject to the then-current Terms provided on Prysm. Your  use of Prysm following any such revision to these Terms constitutes acceptance of such revised Terms.
-
-These Terms constitute the entire agreement between you and Offchain Labs regarding use of Prysm and will supersede all prior agreements whether, written or oral. No usage of trade or other regular practice or method of dealing between the parties will be used to modify, interpret, supplement, or alter the terms of these Terms.
-
-If any portion of these Terms is held invalid or unenforceable, such invalidity or enforceability will not affect the other provisions of these Terms, which will remain in full force and effect, and the invalid or unenforceable portion will be given effect to the greatest extent possible. The failure of a party to require performance of any provision will not affect that party’s right to require performance at any time thereafter, nor will a waiver of any breach or default of these Terms or any provision of these Terms constitute a waiver of any subsequent breach or default or a waiver of the provision itself.
+These Terms constitute the entire agreement between you and Prysmatic Labs regarding use of Prysm and will supersede all prior agreements whether, written or oral. No usage of trade or other regular practice or method of dealing between the parties will be used to modify, interpret, supplement, or alter the terms of these Terms.

+If any portion of these Terms is held invalid or unenforceable, such invalidity or enforceability will not affect the other provisions of these Terms, which will remain in full force and effect, and the invalid or unenforceable portion will be given effect to the greatest extent possible. The failure of a party to require performance of any provision will not affect that party’s right to require performance at any time thereafter, nor will a waiver of any breach or default of these Terms or any provision of these Terms constitute a waiver of any subsequent breach or default or a waiver of the provision itself.
--- a/177
+++ b/177
@@ -27,23 +27,7 @@ http_archive(

 load("@hermetic_cc_toolchain//toolchain:defs.bzl", zig_toolchains = "toolchains")

-# Temporarily use a nightly build until 0.12.0 is released.
-# See: https://github.com/prysmaticlabs/prysm/issues/13130
-zig_toolchains(
-    host_platform_sha256 = {
-        "linux-aarch64": "45afb8e32adde825165f4f293fcea9ecea503f7f9ec0e9bf4435afe70e67fb70",
-        "linux-x86_64": "f136c6a8a0f6adcb057d73615fbcd6f88281b3593f7008d5f7ed514ff925c02e",
-        "macos-aarch64": "05d995853c05243151deff47b60bdc2674f1e794a939eaeca0f42312da031cee",
-        "macos-x86_64": "721754ba5a50f31e8a1f0e1a74cace26f8246576878ac4a8591b0ee7b6db1fc1",
-        "windows-x86_64": "93f5248b2ea8c5ee8175e15b1384e133edc1cd49870b3ea259062a2e04164343",
-    },
-    url_formats = [
-        "https://ziglang.org/builds/zig-{host_platform}-{version}.{_ext}",
-        "https://mirror.bazel.build/ziglang.org/builds/zig-{host_platform}-{version}.{_ext}",
-        "https://prysmaticlabs.com/mirror/ziglang.org/builds/zig-{host_platform}-{version}.{_ext}",
-    ],
-    version = "0.12.0-dev.1349+fa022d1ec",
-)
+zig_toolchains()

 # Register zig sdk toolchains with support for Ubuntu 20.04 (Focal Fossa) which has an EOL date of April, 2025.
 # For ubuntu glibc support, see https://launchpad.net/ubuntu/+source/glibc
@@ -96,29 +80,11 @@ http_archive(
 )

 http_archive(
-    name = "rules_distroless",
-    sha256 = "e64f06e452cd153aeab81f752ccf4642955b3af319e64f7bc7a7c9252f76b10e",
-    strip_prefix = "rules_distroless-f5e678217b57ce3ad2f1c0204bd4e9d416255773",
-    url = "https://github.com/GoogleContainerTools/rules_distroless/archive/f5e678217b57ce3ad2f1c0204bd4e9d416255773.tar.gz",
+    name = "io_bazel_rules_docker",
+    sha256 = "b1e80761a8a8243d03ebca8845e9cc1ba6c82ce7c5179ce2b295cd36f7e394bf",
+    urls = ["https://github.com/bazelbuild/rules_docker/releases/download/v0.25.0/rules_docker-v0.25.0.tar.gz"],
 )

-load("@rules_distroless//distroless:dependencies.bzl", "rules_distroless_dependencies")
-
-rules_distroless_dependencies()
-
-http_archive(
-    name = "distroless",
-    integrity = "sha256-Cf00kUp1NyXA3LzbdyYy4Kda27wbkB8+A9MliTxq4jE=",
-    strip_prefix = "distroless-9dc924b9fe812eec2fa0061824dcad39eb09d0d6",
-    url = "https://github.com/GoogleContainerTools/distroless/archive/9dc924b9fe812eec2fa0061824dcad39eb09d0d6.tar.gz",  # 2024-01-24
-)
-
-load("@aspect_bazel_lib//lib:repositories.bzl", "aspect_bazel_lib_dependencies", "aspect_bazel_lib_register_toolchains")
-
-aspect_bazel_lib_dependencies()
-
-aspect_bazel_lib_register_toolchains()
-
 http_archive(
    name = "rules_oci",
    sha256 = "c71c25ed333a4909d2dd77e0b16c39e9912525a98c7fa85144282be8d04ef54c",
@@ -144,17 +110,13 @@ http_archive(
        # Expose internals of go_test for custom build transitions.
        "//third_party:io_bazel_rules_go_test.patch",
    ],
-    sha256 = "d6ab6b57e48c09523e93050f13698f708428cfd5e619252e369d377af6597707",
+    sha256 = "91585017debb61982f7054c9688857a2ad1fd823fc3f9cb05048b0025c47d023",
    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.43.0/rules_go-v0.43.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.43.0/rules_go-v0.43.0.zip",
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.42.0/rules_go-v0.42.0.zip",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.42.0/rules_go-v0.42.0.zip",
    ],
 )

-load("//:distroless_deps.bzl", "distroless_deps")
-
-distroless_deps()
-
 # Override default import in rules_go with special patch until
 # https://github.com/gogo/protobuf/pull/582 is merged.
 git_repository(
@@ -170,16 +132,67 @@ git_repository(
    # gazelle args: -go_prefix github.com/gogo/protobuf -proto legacy
 )

+load(
+    "@io_bazel_rules_docker//repositories:repositories.bzl",
+    container_repositories = "repositories",
+)
+
+container_repositories()
+
+load(
+    "@io_bazel_rules_docker//container:container.bzl",
+    "container_pull",
+)
+
+# Pulled gcr.io/distroless/cc-debian11:latest on 2022-02-23
+container_pull(
+    name = "cc_image_base_amd64",
+    digest = "sha256:2a0daf90a7deb78465bfca3ef2eee6e91ce0a5706059f05d79d799a51d339523",
+    registry = "gcr.io",
+    repository = "distroless/cc-debian11",
+)
+
+# Pulled gcr.io/distroless/cc-debian11:debug on 2022-02-23
+container_pull(
+    name = "cc_debug_image_base_amd64",
+    digest = "sha256:7bd596f5f200588f13a69c268eea6ce428b222b67cd7428d6a7fef95e75c052a",
+    registry = "gcr.io",
+    repository = "distroless/cc-debian11",
+)
+
+# Pulled from gcr.io/distroless/base-debian11:latest on 2022-02-23
+container_pull(
+    name = "go_image_base_amd64",
+    digest = "sha256:34e682800774ecbd0954b1663d90238505f1ba5543692dbc75feef7dd4839e90",
+    registry = "gcr.io",
+    repository = "distroless/base-debian11",
+)
+
+# Pulled from gcr.io/distroless/base-debian11:debug on 2022-02-23
+container_pull(
+    name = "go_debug_image_base_amd64",
+    digest = "sha256:0f503c6bfd207793bc416f20a35bf6b75d769a903c48f180ad73f60f7b60d7bd",
+    registry = "gcr.io",
+    repository = "distroless/base-debian11",
+)
+
+container_pull(
+    name = "alpine_cc_linux_amd64",
+    digest = "sha256:752aa0c9a88461ffc50c5267bb7497ef03a303e38b2c8f7f2ded9bebe5f1f00e",
+    registry = "index.docker.io",
+    repository = "pinglamb/alpine-glibc",
+)
+
 load("@rules_oci//oci:pull.bzl", "oci_pull")

 # A multi-arch base image
 oci_pull(
    name = "linux_debian11_multiarch_base",  # Debian bullseye
-    digest = "sha256:b82f113425c5b5c714151aaacd8039bc141821cdcd3c65202d42bdf9c43ae60b",  # 2023-12-12
+    digest = "sha256:9b8e0854865dcaf49470b4ec305df45957020fbcf17b71eeb50ffd3bc5bf885d",  # 2023-05-17
    image = "gcr.io/distroless/cc-debian11",
    platforms = [
        "linux/amd64",
-        "linux/arm64/v8",
+        "linux/arm64",
    ],
    reproducible = True,
 )
@@ -193,7 +206,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()

 go_register_toolchains(
-    go_version = "1.21.6",
+    go_version = "1.20.10",
    nogo = "@//:nogo",
 )

@@ -215,8 +228,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "516d551cfb3e50e4ac2f42db0992f4ceb573a7cb1616d727a725c8161485329f",
-    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/refs/tags/v5.3.0.tar.gz",
+    sha256 = "91434d5fd5e1c6eb7b0174fed2afe25e09bddf00e1e4c431db931b2cee4e7773",
+    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/b8413ca42dc92308019d0d4db52c87e9e125c4e9.tar.gz",
 )

 http_archive(
@@ -234,9 +247,9 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.4.0-beta.7"
+consensus_spec_test_version = "v1.4.0-beta.2-hotfix"

-consensus_spec_test_version = "v1.4.0-beta.7-hotfix"
+consensus_spec_version = "v1.4.0-beta.2"

 bls_test_version = "v0.1.1"

@@ -252,7 +265,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "c282c0f86f23f3d2e0f71f5975769a4077e62a7e3c7382a16bd26a7e589811a0",
+    sha256 = "99770a001189f66204a4ef79161c8002bcbbcbd8236f1c6479bd5b83a3c68d42",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_test_version,
 )

@@ -268,7 +281,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "4649c35aa3b8eb0cfdc81bee7c05649f90ef36bede5b0513e1f2e8baf37d6033",
+    sha256 = "56763f6492ee137108271007d62feef60d8e3f1698e53dee4bc4b07e55f7326b",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_test_version,
 )

@@ -284,7 +297,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "c5a03f724f757456ffaabd2a899992a71d2baf45ee4db65ca3518f2b7ee928c8",
+    sha256 = "bc1cac1a991cdc7426efea14385dcf215df85ed3f0572b824ad6a1d7ca0c89ad",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_test_version,
 )

@@ -299,7 +312,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "049c29267310e6b88280f4f834a75866c2f5b9036fa97acb9d9c6db8f64d9118",
+    sha256 = "c5898001aaab2a5bb38a39ff9d17a52f1f9befcc26e63752cbf556040f0c884e",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -330,25 +343,9 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "77e7e3ed65e33b7bb19d30131f4c2bb39e4dfeb188ab9ae84651c3cc7600131d",
-    strip_prefix = "eth2-networks-934c948e69205dcf2deb87e4ae6cc140c335f94d",
-    url = "https://github.com/eth-clients/eth2-networks/archive/934c948e69205dcf2deb87e4ae6cc140c335f94d.tar.gz",
-)
-
-http_archive(
-    name = "goerli_testnet",
-    build_file_content = """
-filegroup(
-    name = "configs",
-    srcs = [
-        "prater/config.yaml",
-    ],
-    visibility = ["//visibility:public"],
-)
-    """,
-    sha256 = "43fc0f55ddff7b511713e2de07aa22846a67432df997296fb4fc09cd8ed1dcdb",
-    strip_prefix = "goerli-6522ac6684693740cd4ddcc2a0662e03702aa4a1",
-    url = "https://github.com/eth-clients/goerli/archive/6522ac6684693740cd4ddcc2a0662e03702aa4a1.tar.gz",
+    sha256 = "2701e1e1a3ec10c673fe7dbdbbe6f02c8ae8c922aebbf6e720d8c72d5458aafe",
+    strip_prefix = "eth2-networks-7b4897888cebef23801540236f73123e21774954",
+    url = "https://github.com/eth-clients/eth2-networks/archive/7b4897888cebef23801540236f73123e21774954.tar.gz",
 )

 http_archive(
@@ -362,17 +359,17 @@ filegroup(
    visibility = ["//visibility:public"],
 )
 """,
-    sha256 = "5f4be6fd088683ea9db45c863b9c5a1884422449e5b59fd2d561d3ba0f73ffd9",
-    strip_prefix = "holesky-9d9aabf2d4de51334ee5fed6c79a4d55097d1a43",
-    url = "https://github.com/eth-clients/holesky/archive/9d9aabf2d4de51334ee5fed6c79a4d55097d1a43.tar.gz",  # 2024-01-22
+    sha256 = "9f66d8d5644982d3d0d2e3d2b9ebe77a5f96638a5d7fcd715599c32818195cb3",
+    strip_prefix = "holesky-ea39b9006210848e13f28d92e12a30548cecd41d",
+    url = "https://github.com/eth-clients/holesky/archive/ea39b9006210848e13f28d92e12a30548cecd41d.tar.gz",  # 2023-09-21
 )

 http_archive(
    name = "com_google_protobuf",
-    sha256 = "9bd87b8280ef720d3240514f884e56a712f2218f0d693b48050c836028940a42",
-    strip_prefix = "protobuf-25.1",
+    sha256 = "4e176116949be52b0408dfd24f8925d1eb674a781ae242a75296b17a1c721395",
+    strip_prefix = "protobuf-23.3",
    urls = [
-        "https://github.com/protocolbuffers/protobuf/archive/v25.1.tar.gz",
+        "https://github.com/protocolbuffers/protobuf/archive/v23.3.tar.gz",
    ],
 )

@@ -406,6 +403,24 @@ load("@prysm//testing/endtoend:deps.bzl", "e2e_deps")

 e2e_deps()

+load(
+    "@io_bazel_rules_docker//go:image.bzl",
+    _go_image_repos = "repositories",
+)
+
+# Golang images
+# This is using gcr.io/distroless/base
+_go_image_repos()
+
+# CC images
+# This is using gcr.io/distroless/base
+load(
+    "@io_bazel_rules_docker//cc:image.bzl",
+    _cc_image_repos = "repositories",
+)
+
+_cc_image_repos()
+
 load("@com_github_atlassian_bazel_tools//gometalinter:deps.bzl", "gometalinter_dependencies")

 gometalinter_dependencies()
--- a/api/BUILD.bazel
+++ b/api/BUILD.bazel
@@ -2,10 +2,7 @@ load("@prysm//tools/go:def.bzl", "go_library")

 go_library(
    name = "go_default_library",
-    srcs = [
-        "constants.go",
-        "headers.go",
-    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api",
+    srcs = ["headers.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v4/api",
    visibility = ["//visibility:public"],
 )
--- a/api/client/BUILD.bazel
+++ b/api/client/BUILD.bazel
@@ -7,7 +7,7 @@ go_library(
        "errors.go",
        "options.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client",
    visibility = ["//visibility:public"],
    deps = ["@com_github_pkg_errors//:go_default_library"],
 )
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -7,13 +7,14 @@ go_library(
        "client.go",
        "doc.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/beacon",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/beacon",
    visibility = ["//visibility:public"],
    deps = [
        "//api/client:go_default_library",
-        "//api/server:go_default_library",
-        "//api/server/structs:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/rpc/apimiddleware:go_default_library",
+        "//beacon-chain/rpc/eth/beacon:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
@@ -21,6 +22,7 @@ go_library(
        "//encoding/ssz/detect:go_default_library",
        "//io/file:go_default_library",
        "//network/forks:go_default_library",
+        "//proto/eth/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
--- a/api/client/beacon/checkpoint.go
+++ b/api/client/beacon/checkpoint.go
@@ -7,16 +7,16 @@ import (

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	base "github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v5/io/file"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	base "github.com/prysmaticlabs/prysm/v4/api/client"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/encoding/ssz/detect"
+	"github.com/prysmaticlabs/prysm/v4/io/file"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/mod/semver"
 )
--- a/api/client/beacon/checkpoint_test.go
+++ b/api/client/beacon/checkpoint_test.go
@@ -9,22 +9,22 @@ import (
 	"net/http"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	blocktest "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks/testing"
-	"github.com/prysmaticlabs/prysm/v5/network/forks"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/api/client"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	blocktest "github.com/prysmaticlabs/prysm/v4/consensus-types/blocks/testing"
+	"github.com/prysmaticlabs/prysm/v4/network/forks"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"

-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/ssz/detect"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 type testRT struct {
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -13,15 +13,18 @@ import (
 	"strconv"
 	"text/template"

+	"github.com/prysmaticlabs/prysm/v4/api/client"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/beacon"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	"github.com/prysmaticlabs/prysm/v4/network/forks"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
+
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/api/server"
-	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/network/forks"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/apimiddleware"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	log "github.com/sirupsen/logrus"
 )

@@ -29,7 +32,7 @@ const (
 	getSignedBlockPath       = "/eth/v2/beacon/blocks"
 	getBlockRootPath         = "/eth/v1/beacon/blocks/{{.Id}}/root"
 	getForkForStatePath      = "/eth/v1/beacon/states/{{.Id}}/fork"
-	getWeakSubjectivityPath  = "/prysm/v1/beacon/weak_subjectivity"
+	getWeakSubjectivityPath  = "/eth/v1/beacon/weak_subjectivity"
 	getForkSchedulePath      = "/eth/v1/config/fork_schedule"
 	getConfigSpecPath        = "/eth/v1/config/spec"
 	getStatePath             = "/eth/v2/debug/beacon/states"
@@ -147,8 +150,8 @@ func (c *Client) GetFork(ctx context.Context, stateId StateOrBlockId) (*ethpb.Fo
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting fork by state id = %s", stateId)
 	}
-	fr := &structs.Fork{}
-	dataWrapper := &struct{ Data *structs.Fork }{Data: fr}
+	fr := &shared.Fork{}
+	dataWrapper := &struct{ Data *shared.Fork }{Data: fr}
 	err = json.Unmarshal(body, dataWrapper)
 	if err != nil {
 		return nil, errors.Wrap(err, "error decoding json response in GetFork")
@@ -176,12 +179,12 @@ func (c *Client) GetForkSchedule(ctx context.Context) (forks.OrderedSchedule, er
 }

 // GetConfigSpec retrieve the current configs of the network used by the beacon node.
-func (c *Client) GetConfigSpec(ctx context.Context) (*structs.GetSpecResponse, error) {
+func (c *Client) GetConfigSpec(ctx context.Context) (*v1.SpecResponse, error) {
 	body, err := c.Get(ctx, getConfigSpecPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting configSpecPath")
 	}
-	fsr := &structs.GetSpecResponse{}
+	fsr := &v1.SpecResponse{}
 	err = json.Unmarshal(body, fsr)
 	if err != nil {
 		return nil, err
@@ -256,16 +259,16 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 	if err != nil {
 		return nil, err
 	}
-	v := &structs.GetWeakSubjectivityResponse{}
+	v := &apimiddleware.WeakSubjectivityResponse{}
 	err = json.Unmarshal(body, v)
 	if err != nil {
 		return nil, err
 	}
-	epoch, err := strconv.ParseUint(v.Data.WsCheckpoint.Epoch, 10, 64)
+	epoch, err := strconv.ParseUint(v.Data.Checkpoint.Epoch, 10, 64)
 	if err != nil {
 		return nil, err
 	}
-	blockRoot, err := hexutil.Decode(v.Data.WsCheckpoint.Root)
+	blockRoot, err := hexutil.Decode(v.Data.Checkpoint.Root)
 	if err != nil {
 		return nil, err
 	}
@@ -282,7 +285,7 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData

 // SubmitChangeBLStoExecution calls a beacon API endpoint to set the withdrawal addresses based on the given signed messages.
 // If the API responds with something other than OK there will be failure messages associated to the corresponding request message.
-func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*structs.SignedBLSToExecutionChange) error {
+func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*shared.SignedBLSToExecutionChange) error {
 	u := c.BaseURL().ResolveReference(&url.URL{Path: changeBLStoExecutionPath})
 	body, err := json.Marshal(request)
 	if err != nil {
@@ -303,7 +306,7 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*stru
 	if resp.StatusCode != http.StatusOK {
 		decoder := json.NewDecoder(resp.Body)
 		decoder.DisallowUnknownFields()
-		errorJson := &server.IndexedVerificationFailureError{}
+		errorJson := &apimiddleware.IndexedVerificationFailureErrorJson{}
 		if err := decoder.Decode(errorJson); err != nil {
 			return errors.Wrapf(err, "failed to decode error JSON for %s", resp.Request.URL)
 		}
@@ -321,12 +324,12 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*stru

 // GetBLStoExecutionChanges gets all the set withdrawal messages in the node's operation pool.
 // Returns a struct representation of json response.
-func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToExecutionChangesPoolResponse, error) {
+func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*beacon.BLSToExecutionChangesPoolResponse, error) {
 	body, err := c.Get(ctx, changeBLStoExecutionPath)
 	if err != nil {
 		return nil, err
 	}
-	poolResponse := &structs.BLSToExecutionChangesPoolResponse{}
+	poolResponse := &beacon.BLSToExecutionChangesPoolResponse{}
 	err = json.Unmarshal(body, poolResponse)
 	if err != nil {
 		return nil, err
@@ -335,7 +338,7 @@ func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToEx
 }

 type forkScheduleResponse struct {
-	Data []structs.Fork
+	Data []shared.Fork
 }

 func (fsr *forkScheduleResponse) OrderedForkSchedule() (forks.OrderedSchedule, error) {
--- a/api/client/beacon/client_test.go
+++ b/api/client/beacon/client_test.go
@@ -4,8 +4,8 @@ import (
 	"net/url"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/api/client"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestParseNodeVersion(t *testing.T) {
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -8,10 +8,10 @@ go_library(
        "errors.go",
        "types.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/builder",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/builder",
    visibility = ["//visibility:public"],
    deps = [
-        "//api/server/structs:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//config/fieldparams:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
@@ -20,6 +20,8 @@ go_library(
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//monitoring/tracing:go_default_library",
+        "//network:go_default_library",
+        "//network/authorization:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
@@ -40,7 +42,7 @@ go_test(
    data = glob(["testdata/**"]),
    embed = [":go_default_library"],
    deps = [
-        "//api/server/structs:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
--- a/api/client/builder/bid.go
+++ b/api/client/builder/bid.go
@@ -3,11 +3,12 @@ package builder
 import (
 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
-	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	consensus_types "github.com/prysmaticlabs/prysm/v4/consensus-types"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 )

 // SignedBid is an interface describing the method set of a signed builder bid.
@@ -21,7 +22,7 @@ type SignedBid interface {
 // Bid is an interface describing the method set of a builder bid.
 type Bid interface {
 	Header() (interfaces.ExecutionData, error)
-	BlobKzgCommitments() ([][]byte, error)
+	BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error)
 	Value() []byte
 	Pubkey() []byte
 	Version() int
@@ -114,9 +115,9 @@ func (b builderBid) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeader(b.p.Header)
 }

-// BlobKzgCommitments --
-func (b builderBid) BlobKzgCommitments() ([][]byte, error) {
-	return [][]byte{}, errors.New("blob kzg commitments not available before Deneb")
+// BlindedBlobsBundle --
+func (b builderBid) BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error) {
+	return nil, errors.New("blinded blobs bundle not available before Deneb")
 }

 // Version --
@@ -165,12 +166,12 @@ func WrappedBuilderBidCapella(p *ethpb.BuilderBidCapella) (Bid, error) {
 // Header returns the execution data interface.
 func (b builderBidCapella) Header() (interfaces.ExecutionData, error) {
 	// We have to convert big endian to little endian because the value is coming from the execution layer.
-	return blocks.WrappedExecutionPayloadHeaderCapella(b.p.Header, blocks.PayloadValueToWei(b.p.Value))
+	return blocks.WrappedExecutionPayloadHeaderCapella(b.p.Header, blocks.PayloadValueToGwei(b.p.Value))
 }

-// BlobKzgCommitments --
-func (b builderBidCapella) BlobKzgCommitments() ([][]byte, error) {
-	return [][]byte{}, errors.New("blob kzg commitments not available before Deneb")
+// BlindedBlobsBundle --
+func (b builderBidCapella) BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error) {
+	return nil, errors.New("blinded blobs bundle not available before Deneb")
 }

 // Version --
@@ -249,12 +250,12 @@ func (b builderBidDeneb) HashTreeRootWith(hh *ssz.Hasher) error {
 // Header --
 func (b builderBidDeneb) Header() (interfaces.ExecutionData, error) {
 	// We have to convert big endian to little endian because the value is coming from the execution layer.
-	return blocks.WrappedExecutionPayloadHeaderDeneb(b.p.Header, blocks.PayloadValueToWei(b.p.Value))
+	return blocks.WrappedExecutionPayloadHeaderDeneb(b.p.Header, blocks.PayloadValueToGwei(b.p.Value))
 }

-// BlobKzgCommitments --
-func (b builderBidDeneb) BlobKzgCommitments() ([][]byte, error) {
-	return b.p.BlobKzgCommitments, nil
+// BlindedBlobsBundle --
+func (b builderBidDeneb) BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error) {
+	return b.p.BlindedBlobsBundle, nil
 }

 type signedBuilderBidDeneb struct {
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"math/big"
 	"net"
 	"net/http"
 	"net/url"
@@ -14,15 +13,17 @@ import (
 	"text/template"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v4/network"
+	"github.com/prysmaticlabs/prysm/v4/network/authorization"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	log "github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -88,7 +89,7 @@ type BuilderClient interface {
 	NodeURL() string
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error)
 	Status(ctx context.Context) error
 }

@@ -103,7 +104,8 @@ type Client struct {
 // `host` is the base host + port used to construct request urls. This value can be
 // a URL string, or NewClient will assume an http endpoint if just `host:port` is used.
 func NewClient(host string, opts ...ClientOpt) (*Client, error) {
-	u, err := urlForHost(host)
+	endpoint := covertEndPoint(host)
+	u, err := urlForHost(endpoint.Url)
 	if err != nil {
 		return nil, err
 	}
@@ -119,7 +121,8 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {

 func urlForHost(h string) (*url.URL, error) {
 	// try to parse as url (being permissive)
-	if u, err := url.Parse(h); err == nil && u.Host != "" {
+	u, err := url.Parse(h)
+	if err == nil && u.Host != "" {
 		return u, nil
 	}
 	// try to parse as host:port
@@ -137,7 +140,7 @@ 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.
+// do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder/types.go.
 func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, err error) {
 	ctx, span := trace.StartSpan(ctx, "builder.client.do")
 	defer func() {
@@ -267,9 +270,13 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 		tracing.AnnotateError(span, err)
 		return err
 	}
-	vs := make([]*structs.SignedValidatorRegistration, len(svr))
+	vs := make([]*shared.SignedValidatorRegistration, len(svr))
 	for i := 0; i < len(svr); i++ {
-		vs[i] = structs.SignedValidatorRegistrationFromConsensus(svr[i])
+		svrJson, err := shared.SignedValidatorRegistrationFromConsensus(svr[i])
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("failed to encode to SignedValidatorRegistration at index %d", i))
+		}
+		vs[i] = svrJson
 	}
 	body, err := json.Marshal(vs)
 	if err != nil {
@@ -284,7 +291,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid

 // 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) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	if !sb.IsBlinded() {
 		return nil, nil, errNotBlinded
 	}
@@ -294,7 +301,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := structs.SignedBlindedBeaconBlockBellatrixFromConsensus(&ethpb.SignedBlindedBeaconBlockBellatrix{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockBellatrixFromConsensus(&ethpb.SignedBlindedBeaconBlockBellatrix{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockBellatrix to json marshalable type")
 		}
@@ -331,7 +338,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := structs.SignedBlindedBeaconBlockCapellaFromConsensus(&ethpb.SignedBlindedBeaconBlockCapella{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockCapellaFromConsensus(&ethpb.SignedBlindedBeaconBlockCapella{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockCapella to json marshalable type")
 		}
@@ -358,7 +365,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
 		}
-		payload, err := blocks.WrappedExecutionPayloadCapella(p, big.NewInt(0))
+		payload, err := blocks.WrappedExecutionPayloadCapella(p, 0)
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
 		}
@@ -368,9 +375,9 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := structs.SignedBlindedBeaconBlockDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockDeneb{Message: psb.Message, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockContentsDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockAndBlobsDeneb{SignedBlindedBlock: psb, SignedBlindedBlobSidecars: blobs})
 		if err != nil {
-			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockDeneb to json marshalable type")
+			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockContentsDeneb to json marshalable type")
 		}
 		body, err := json.Marshal(b)
 		if err != nil {
@@ -395,7 +402,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
 		}
-		payload, err := blocks.WrappedExecutionPayloadDeneb(p, big.NewInt(0))
+		payload, err := blocks.WrappedExecutionPayloadDeneb(p, 0)
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
 		}
@@ -424,29 +431,38 @@ 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.StatusNoContent:
+	case 204:
 		log.WithError(ErrNoContent).Debug(msg)
 		return ErrNoContent
-	case http.StatusBadRequest:
+	case 400:
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		log.WithError(ErrBadRequest).Debug(msg)
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
 		return errors.Wrap(ErrBadRequest, errMessage.Message)
-	case http.StatusNotFound:
+	case 404:
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		log.WithError(ErrNotFound).Debug(msg)
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
 		return errors.Wrap(ErrNotFound, errMessage.Message)
-	case http.StatusInternalServerError:
-		log.WithError(ErrNotOK).Debug(msg)
+	case 500:
 		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
 			return errors.Wrap(jsonErr, "unable to read response body")
 		}
+		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, errMessage.Message)
 	default:
 		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, fmt.Sprintf("unsupported error code: %d", response.StatusCode))
 	}
 }
+
+func covertEndPoint(ep string) network.Endpoint {
+	return network.Endpoint{
+		Url: ep,
+		Auth: network.AuthorizationData{ // Auth is not used for builder.
+			Method: authorization.None,
+			Value:  "",
+		}}
+}
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -12,16 +12,18 @@ import (
 	"strconv"
 	"testing"

+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	types "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	log "github.com/sirupsen/logrus"
 )

@@ -268,20 +270,28 @@ func TestClient_GetHeader(t *testing.T) {
 		bidValue := bytesutil.ReverseByteOrder(bid.Value())
 		require.DeepEqual(t, bidValue, value.Bytes())
 		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
-		kcgCommitments, err := bid.BlobKzgCommitments()
+		bundle, err := bid.BlindedBlobsBundle()
 		require.NoError(t, err)
-		require.Equal(t, len(kcgCommitments) > 0, true)
-		for i := range kcgCommitments {
-			require.Equal(t, len(kcgCommitments[i]) == 48, true)
+		require.Equal(t, len(bundle.BlobRoots) <= fieldparams.MaxBlobsPerBlock && len(bundle.BlobRoots) > 0, true)
+		for i := range bundle.BlobRoots {
+			require.Equal(t, len(bundle.BlobRoots[i]) == fieldparams.RootLength, true)
+		}
+		require.Equal(t, len(bundle.KzgCommitments) > 0, true)
+		for i := range bundle.KzgCommitments {
+			require.Equal(t, len(bundle.KzgCommitments[i]) == 48, true)
+		}
+		require.Equal(t, len(bundle.Proofs) > 0, true)
+		for i := range bundle.Proofs {
+			require.Equal(t, len(bundle.Proofs[i]) == 48, true)
 		}
 	})
-	t.Run("deneb, too many kzg commitments", func(t *testing.T) {
+	t.Run("deneb, no bundle", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, expectedPath, r.URL.Path)
 				return &http.Response{
 					StatusCode: http.StatusOK,
-					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebTooManyBlobs)),
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebNoBundle)),
 					Request:    r.Clone(ctx),
 				}, nil
 			}),
@@ -290,9 +300,27 @@ func TestClient_GetHeader(t *testing.T) {
 			hc:      hc,
 			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)
+		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))
+		value, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
+		require.NoError(t, err)
+		require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", bid.Value()))
+		bidValue := bytesutil.ReverseByteOrder(bid.Value())
+		require.DeepEqual(t, bidValue, value.Bytes())
+		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
+		bundle, err := bid.BlindedBlobsBundle()
+		require.NoError(t, err)
+		require.Equal(t, (*v1.BlindedBlobsBundle)(nil), bundle)
 	})
+
 	t.Run("unsupported version", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -334,7 +362,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb, nil)
 		require.NoError(t, err)
 		require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash()))
 		bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
@@ -360,7 +388,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockCapella(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbb, nil)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -371,17 +399,18 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
 	t.Run("deneb", func(t *testing.T) {
-		test := testSignedBlindedBeaconBlockDeneb(t)
+
+		test := testSignedBlindedBeaconBlockAndBlobsDeneb(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"))
-				var req structs.SignedBlindedBeaconBlockDeneb
+				var req shared.SignedBlindedBeaconBlockContentsDeneb
 				err := json.NewDecoder(r.Body).Decode(&req)
 				require.NoError(t, err)
-				block, err := req.ToConsensus()
+				block, err := req.SignedBlindedBlock.ToConsensus()
 				require.NoError(t, err)
-				require.DeepEqual(t, block, test)
+				require.DeepEqual(t, block, test.SignedBlindedBlock)
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadDeneb)),
@@ -394,10 +423,10 @@ func TestSubmitBlindedBlock(t *testing.T) {
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}

-		sbb, err := blocks.NewSignedBeaconBlock(test)
+		sbb, err := blocks.NewSignedBeaconBlock(test.SignedBlindedBlock)
 		require.NoError(t, err)

-		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb)
+		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb, test.SignedBlindedBlobSidecars)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -407,6 +436,9 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 		require.NotNil(t, blobBundle)
+		require.Equal(t, hexutil.Encode(blobBundle.Blobs[0]), hexutil.Encode(make([]byte, fieldparams.BlobLength)))
+		require.Equal(t, hexutil.Encode(blobBundle.KzgCommitments[0]), "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f")
+		require.Equal(t, hexutil.Encode(blobBundle.Proofs[0]), "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a")
 	})
 	t.Run("mismatched versions, expected bellatrix got capella", func(t *testing.T) {
 		hc := &http.Client{
@@ -425,13 +457,13 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		_, _, err = c.SubmitBlindedBlock(ctx, sbbb)
+		_, _, err = c.SubmitBlindedBlock(ctx, sbbb, nil)
 		require.ErrorContains(t, "not a bellatrix payload", err)
 	})
 	t.Run("not blinded", func(t *testing.T) {
-		sbb, err := blocks.NewSignedBeaconBlock(&eth.SignedBeaconBlockBellatrix{Block: &eth.BeaconBlockBellatrix{Body: &eth.BeaconBlockBodyBellatrix{ExecutionPayload: &v1.ExecutionPayload{}}}})
+		sbb, err := blocks.NewSignedBeaconBlock(&eth.SignedBeaconBlockBellatrix{Block: &eth.BeaconBlockBellatrix{Body: &eth.BeaconBlockBodyBellatrix{}}})
 		require.NoError(t, err)
-		_, _, err = (&Client{}).SubmitBlindedBlock(ctx, sbb)
+		_, _, err = (&Client{}).SubmitBlindedBlock(ctx, sbb, nil)
 		require.ErrorIs(t, err, errNotBlinded)
 	})
 }
@@ -721,70 +753,91 @@ func testSignedBlindedBeaconBlockCapella(t *testing.T) *eth.SignedBlindedBeaconB
 	}
 }

-func testSignedBlindedBeaconBlockDeneb(t *testing.T) *eth.SignedBlindedBeaconBlockDeneb {
-	basebytes, err := bytesutil.Uint256ToSSZBytes("14074904626401341155369551180448584754667373453244490859944217516317499064576")
+func testSignedBlindedBeaconBlockAndBlobsDeneb(t *testing.T) *eth.SignedBlindedBeaconBlockAndBlobsDeneb {
+	basebytes, err := shared.Uint256ToSSZBytes("14074904626401341155369551180448584754667373453244490859944217516317499064576")
 	if err != nil {
 		log.Error(err)
 	}
-	return &eth.SignedBlindedBeaconBlockDeneb{
-		Message: &eth.BlindedBeaconBlockDeneb{
-			Slot:          1,
-			ProposerIndex: 1,
-			ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-			StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-			Body: &eth.BlindedBeaconBlockBodyDeneb{
-				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"),
+	return &eth.SignedBlindedBeaconBlockAndBlobsDeneb{
+		SignedBlindedBlock: &eth.SignedBlindedBeaconBlockDeneb{
+			Message: &eth.BlindedBeaconBlockDeneb{
+				Slot:          1,
+				ProposerIndex: 1,
+				ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				Body: &eth.BlindedBeaconBlockBodyDeneb{
+					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"),
 							},
-							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"),
+							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"),
 							},
-							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
 					},
-				},
-				AttesterSlashings: []*eth.AttesterSlashing{
-					{
-						Attestation_1: &eth.IndexedAttestation{
-							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"),
+					AttesterSlashings: []*eth.AttesterSlashing{
+						{
+							Attestation_1: &eth.IndexedAttestation{
+								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.IndexedAttestation{
+								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"),
 							},
-							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
-						Attestation_2: &eth.IndexedAttestation{
-							AttestingIndices: []uint64{1},
+					},
+					Attestations: []*eth.Attestation{
+						{
+							AggregationBits: bitfield.Bitlist{0x01},
 							Data: &eth.AttestationData{
 								Slot:            1,
 								CommitteeIndex:  1,
@@ -801,72 +854,68 @@ func testSignedBlindedBeaconBlockDeneb(t *testing.T) *eth.SignedBlindedBeaconBlo
 							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
 					},
-				},
-				Attestations: []*eth.Attestation{
-					{
-						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"),
+					Deposits: []*eth.Deposit{
+						{
+							Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+							Data: &eth.Deposit_Data{
+								PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+								WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Amount:                1,
+								Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 							},
 						},
-						Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 					},
-				},
-				Deposits: []*eth.Deposit{
-					{
-						Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
-						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"),
 						},
 					},
-				},
-				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"),
+					},
+					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,
 					},
-				},
-				SyncAggregate: &eth.SyncAggregate{
-					SyncCommitteeSignature: make([]byte, 96),
-					SyncCommitteeBits:      ezDecode(t, "0x6451e9f951ebf05edc01de67e593484b672877054f055903ff0df1a1a945cf30ca26bb4d4b154f94a1bc776bcf5d0efb3603e1f9b8ee2499ccdcfe2a18cef458"),
-				},
-				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"),
+		},
+		SignedBlindedBlobSidecars: []*eth.SignedBlindedBlobSidecar{
+			{
+				Message: &eth.BlindedBlobSidecar{
+					BlockRoot:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					Index:           0,
+					Slot:            1,
+					BlockParentRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					ProposerIndex:   1,
+					BlobRoot:        ezDecode(t, "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"),
+					KzgCommitment:   ezDecode(t, "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"),
+					KzgProof:        ezDecode(t, "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"),
+				},
+				Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+			},
 		},
-		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 	}
 }

--- a/api/client/builder/testing/BUILD.bazel
+++ b/api/client/builder/testing/BUILD.bazel
@@ -3,7 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library")
 go_library(
    name = "go_default_library",
    srcs = ["mock.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/builder/testing",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/builder/testing",
    visibility = ["//visibility:public"],
    deps = [
        "//api/client/builder:go_default_library",
--- a/api/client/builder/testing/mock.go
+++ b/api/client/builder/testing/mock.go
@@ -3,12 +3,12 @@ package testing
 import (
 	"context"

-	"github.com/prysmaticlabs/prysm/v5/api/client/builder"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/api/client/builder"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )

 // MockClient is a mock implementation of BuilderClient.
@@ -41,7 +41,7 @@ func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedVali
 }

 // SubmitBlindedBlock --
-func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock, _ []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	return nil, nil, nil
 }

--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
@@ -8,12 +8,12 @@ import (

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/math"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	types "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/math"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )

 var errInvalidUint256 = errors.New("invalid Uint256")
@@ -117,7 +117,7 @@ type VersionResponse struct {
 	Version string `json:"version"`
 }

-// ExecHeaderResponse is a JSON representation of the builder API header response for Bellatrix.
+// ExecHeaderResponse is a JSON representation of  the builder API header response for Bellatrix.
 type ExecHeaderResponse struct {
 	Version string `json:"version"`
 	Data    struct {
@@ -357,45 +357,6 @@ func FromProtoCapella(payload *v1.ExecutionPayloadCapella) (ExecutionPayloadCape
 	}, nil
 }

-func FromProtoDeneb(payload *v1.ExecutionPayloadDeneb) (ExecutionPayloadDeneb, error) {
-	bFee, err := sszBytesToUint256(payload.BaseFeePerGas)
-	if err != nil {
-		return ExecutionPayloadDeneb{}, err
-	}
-	txs := make([]hexutil.Bytes, len(payload.Transactions))
-	for i := range payload.Transactions {
-		txs[i] = bytesutil.SafeCopyBytes(payload.Transactions[i])
-	}
-	withdrawals := make([]Withdrawal, len(payload.Withdrawals))
-	for i, w := range payload.Withdrawals {
-		withdrawals[i] = Withdrawal{
-			Index:          Uint256{Int: big.NewInt(0).SetUint64(w.Index)},
-			ValidatorIndex: Uint256{Int: big.NewInt(0).SetUint64(uint64(w.ValidatorIndex))},
-			Address:        bytesutil.SafeCopyBytes(w.Address),
-			Amount:         Uint256{Int: big.NewInt(0).SetUint64(w.Amount)},
-		}
-	}
-	return ExecutionPayloadDeneb{
-		ParentHash:    bytesutil.SafeCopyBytes(payload.ParentHash),
-		FeeRecipient:  bytesutil.SafeCopyBytes(payload.FeeRecipient),
-		StateRoot:     bytesutil.SafeCopyBytes(payload.StateRoot),
-		ReceiptsRoot:  bytesutil.SafeCopyBytes(payload.ReceiptsRoot),
-		LogsBloom:     bytesutil.SafeCopyBytes(payload.LogsBloom),
-		PrevRandao:    bytesutil.SafeCopyBytes(payload.PrevRandao),
-		BlockNumber:   Uint64String(payload.BlockNumber),
-		GasLimit:      Uint64String(payload.GasLimit),
-		GasUsed:       Uint64String(payload.GasUsed),
-		Timestamp:     Uint64String(payload.Timestamp),
-		ExtraData:     bytesutil.SafeCopyBytes(payload.ExtraData),
-		BaseFeePerGas: bFee,
-		BlockHash:     bytesutil.SafeCopyBytes(payload.BlockHash),
-		Transactions:  txs,
-		Withdrawals:   withdrawals,
-		BlobGasUsed:   Uint64String(payload.BlobGasUsed),
-		ExcessBlobGas: Uint64String(payload.ExcessBlobGas),
-	}, nil
-}
-
 // ExecHeaderResponseCapella is the response of builder API /eth/v1/builder/header/{slot}/{parent_hash}/{pubkey} for Capella.
 type ExecHeaderResponseCapella struct {
 	Data struct {
@@ -908,19 +869,16 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 	if err != nil {
 		return nil, err
 	}
-	if len(bb.BlobKzgCommitments) > fieldparams.MaxBlobsPerBlock {
-		return nil, fmt.Errorf("too many blob commitments: %d", len(bb.BlobKzgCommitments))
-	}
-	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
-	for i, commit := range bb.BlobKzgCommitments {
-		if len(commit) != fieldparams.BLSPubkeyLength {
-			return nil, fmt.Errorf("commitment length %d is not %d", len(commit), fieldparams.BLSPubkeyLength)
+	var bundle *v1.BlindedBlobsBundle
+	if bb.BlindedBlobsBundle != nil {
+		bundle, err = bb.BlindedBlobsBundle.ToProto()
+		if err != nil {
+			return nil, err
 		}
-		kzgCommitments[i] = bytesutil.SafeCopyBytes(commit)
 	}
 	return &eth.BuilderBidDeneb{
 		Header:             header,
-		BlobKzgCommitments: kzgCommitments,
+		BlindedBlobsBundle: bundle,
 		Value:              bytesutil.SafeCopyBytes(bb.Value.SSZBytes()),
 		Pubkey:             bytesutil.SafeCopyBytes(bb.Pubkey),
 	}, nil
@@ -929,11 +887,42 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 // BuilderBidDeneb is a field of ExecHeaderResponseDeneb.
 type BuilderBidDeneb struct {
 	Header             *ExecutionPayloadHeaderDeneb `json:"header"`
-	BlobKzgCommitments []hexutil.Bytes              `json:"blob_kzg_commitments"`
+	BlindedBlobsBundle *BlindedBlobsBundle          `json:"blinded_blobs_bundle"`
 	Value              Uint256                      `json:"value"`
 	Pubkey             hexutil.Bytes                `json:"pubkey"`
 }

+// BlindedBlobsBundle is a field of BuilderBidDeneb and represents the blinded blobs of the associated header.
+type BlindedBlobsBundle struct {
+	KzgCommitments []hexutil.Bytes `json:"commitments"`
+	Proofs         []hexutil.Bytes `json:"proofs"`
+	BlobRoots      []hexutil.Bytes `json:"blob_roots"`
+}
+
+// ToProto creates a BlindedBlobsBundle Proto from BlindedBlobsBundle.
+func (r *BlindedBlobsBundle) ToProto() (*v1.BlindedBlobsBundle, error) {
+	kzg := make([][]byte, len(r.KzgCommitments))
+	for i := range kzg {
+		kzg[i] = bytesutil.SafeCopyBytes(r.KzgCommitments[i])
+	}
+
+	proofs := make([][]byte, len(r.Proofs))
+	for i := range proofs {
+		proofs[i] = bytesutil.SafeCopyBytes(r.Proofs[i])
+	}
+
+	blobRoots := make([][]byte, len(r.BlobRoots))
+	for i := range blobRoots {
+		blobRoots[i] = bytesutil.SafeCopyBytes(r.BlobRoots[i])
+	}
+
+	return &v1.BlindedBlobsBundle{
+		KzgCommitments: kzg,
+		Proofs:         proofs,
+		BlobRoots:      blobRoots,
+	}, nil
+}
+
 // ExecutionPayloadHeaderDeneb a field part of the BuilderBidDeneb.
 type ExecutionPayloadHeaderDeneb struct {
 	ParentHash       hexutil.Bytes `json:"parent_hash"`
@@ -1063,16 +1052,6 @@ type BlobsBundle struct {

 // ToProto returns a BlobsBundle Proto.
 func (b BlobsBundle) ToProto() (*v1.BlobsBundle, error) {
-	if len(b.Blobs) > fieldparams.MaxBlobCommitmentsPerBlock {
-		return nil, fmt.Errorf("blobs length %d is more than max %d", len(b.Blobs), fieldparams.MaxBlobCommitmentsPerBlock)
-	}
-	if len(b.Commitments) != len(b.Blobs) {
-		return nil, fmt.Errorf("commitments length %d does not equal blobs length %d", len(b.Commitments), len(b.Blobs))
-	}
-	if len(b.Proofs) != len(b.Blobs) {
-		return nil, fmt.Errorf("proofs length %d does not equal blobs length %d", len(b.Proofs), len(b.Blobs))
-	}
-
 	commitments := make([][]byte, len(b.Commitments))
 	for i := range b.Commitments {
 		if len(b.Commitments[i]) != fieldparams.BLSPubkeyLength {
@@ -1087,6 +1066,9 @@ func (b BlobsBundle) ToProto() (*v1.BlobsBundle, error) {
 		}
 		proofs[i] = bytesutil.SafeCopyBytes(b.Proofs[i])
 	}
+	if len(b.Blobs) > fieldparams.MaxBlobsPerBlock {
+		return nil, fmt.Errorf("blobs length %d is more than max %d", len(b.Blobs), fieldparams.MaxBlobsPerBlock)
+	}
 	blobs := make([][]byte, len(b.Blobs))
 	for i := range b.Blobs {
 		if len(b.Blobs[i]) != fieldparams.BlobLength {
@@ -1101,28 +1083,6 @@ func (b BlobsBundle) ToProto() (*v1.BlobsBundle, error) {
 	}, nil
 }

-// FromBundleProto converts the proto bundle type to the builder
-// type.
-func FromBundleProto(bundle *v1.BlobsBundle) *BlobsBundle {
-	commitments := make([]hexutil.Bytes, len(bundle.KzgCommitments))
-	for i := range bundle.KzgCommitments {
-		commitments[i] = bytesutil.SafeCopyBytes(bundle.KzgCommitments[i])
-	}
-	proofs := make([]hexutil.Bytes, len(bundle.Proofs))
-	for i := range bundle.Proofs {
-		proofs[i] = bytesutil.SafeCopyBytes(bundle.Proofs[i])
-	}
-	blobs := make([]hexutil.Bytes, len(bundle.Blobs))
-	for i := range bundle.Blobs {
-		blobs[i] = bytesutil.SafeCopyBytes(bundle.Blobs[i])
-	}
-	return &BlobsBundle{
-		Commitments: commitments,
-		Proofs:      proofs,
-		Blobs:       blobs,
-	}
-}
-
 // ToProto returns ExecutionPayloadDeneb Proto and BlobsBundle Proto separately.
 func (r *ExecPayloadResponseDeneb) ToProto() (*v1.ExecutionPayloadDeneb, *v1.BlobsBundle, error) {
 	if r.Data == nil {
--- a/api/client/builder/types_test.go
+++ b/api/client/builder/types_test.go
@@ -13,13 +13,13 @@ import (

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v5/math"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/math"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func ezDecode(t *testing.T, s string) []byte {
@@ -38,7 +38,8 @@ func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
 		},
 		Signature: make([]byte, 96),
 	}
-	a := structs.SignedValidatorRegistrationFromConsensus(svr)
+	a, err := shared.SignedValidatorRegistrationFromConsensus(svr)
+	require.NoError(t, err)
 	je, err := json.Marshal(a)
 	require.NoError(t, err)
 	// decode with a struct w/ plain strings so we can check the string encoding of the hex fields
@@ -55,7 +56,7 @@ func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
 	require.Equal(t, "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", un.Message.Pubkey)

 	t.Run("roundtrip", func(t *testing.T) {
-		b := &structs.SignedValidatorRegistration{}
+		b := &shared.SignedValidatorRegistration{}
 		if err := json.Unmarshal(je, b); err != nil {
 			require.NoError(t, err)
 		}
@@ -141,9 +142,17 @@ var testExampleHeaderResponseDeneb = `{
 		"blob_gas_used": "1",	
 		"excess_blob_gas": "2"	
      },
-      "blob_kzg_commitments": [
+      "blinded_blobs_bundle": {
+        "commitments": [
          "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
-	  ],
+        ],
+        "proofs": [
+          "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
+        ],
+        "blob_roots": [
+          "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"
+        ]
+      },
      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
    },
@@ -209,39 +218,6 @@ var testExampleHeaderResponseUnknownVersion = `{
  }
 }`

-var testExampleHeaderResponseDenebTooManyBlobs = `{
-  "version": "deneb",
-  "data": {
-    "message": {
-      "header": {
-        "parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-        "state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "block_number": "1",
-        "gas_limit": "1",
-        "gas_used": "1",
-        "timestamp": "1",
-        "extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
-		"block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "transactions_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-        "withdrawals_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"blob_gas_used": "1",	
-		"excess_blob_gas": "2"	
-      },
-      "blob_kzg_commitments": [
-          "","","","","","",""
-	  ],
-      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
-      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
-    },
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
-  }
-}`
-
 func TestExecutionHeaderResponseUnmarshal(t *testing.T) {
 	hr := &ExecHeaderResponse{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponse), hr))
@@ -661,151 +637,6 @@ var testExampleExecutionPayloadDeneb = fmt.Sprintf(`{
  }
 }`, hexutil.Encode(make([]byte, fieldparams.BlobLength)))

-var testExampleExecutionPayloadDenebTooManyBlobs = fmt.Sprintf(`{
-  "version": "deneb",
-  "data": {
-	"execution_payload":{
-		"parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-		"state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-		"prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"block_number": "1",
-		"gas_limit": "1",
-		"gas_used": "1",
-		"timestamp": "1",
-		"extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
-		"block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"transactions": [
-		  "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-		],
-		"withdrawals": [
-		  {
-			"index": "1",
-			"validator_index": "1",
-			"address": "0xcf8e0d4e9587369b2301d0790347320302cc0943",
-			"amount": "1"
-		  }
-		],
-		"blob_gas_used": "2",
- 		"excess_blob_gas": "3"
-	  },
-	"blobs_bundle": {
-      "commitments": [
-        "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
-      ],
-      "proofs": [
-        "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
-      ],
-      "blobs": %s
-    }
-  }
-}`, beyondMaxEmptyBlobs())
-
-func beyondMaxEmptyBlobs() string {
-	moreThanMax := fieldparams.MaxBlobCommitmentsPerBlock + 2
-	blobs := make([]string, moreThanMax)
-	b, err := json.Marshal(blobs)
-	if err != nil {
-		panic(err)
-	}
-	return string(b)
-}
-
-var testExampleExecutionPayloadDenebDifferentCommitmentCount = fmt.Sprintf(`{
-  "version": "deneb",
-  "data": {
-	"execution_payload":{
-		"parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-		"state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-		"prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"block_number": "1",
-		"gas_limit": "1",
-		"gas_used": "1",
-		"timestamp": "1",
-		"extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
-		"block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"transactions": [
-		  "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-		],
-		"withdrawals": [
-		  {
-			"index": "1",
-			"validator_index": "1",
-			"address": "0xcf8e0d4e9587369b2301d0790347320302cc0943",
-			"amount": "1"
-		  }
-		],
-		"blob_gas_used": "2",
- 		"excess_blob_gas": "3"
-	  },
-	"blobs_bundle": {
-      "commitments": [
-        "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f",
-        "0xc00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
-      ],
-      "proofs": [
-        "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
-      ],
-      "blobs": [
-        "%s"
-      ]
-    }
-  }
-}`, hexutil.Encode(make([]byte, fieldparams.BlobLength)))
-
-var testExampleExecutionPayloadDenebDifferentProofCount = fmt.Sprintf(`{
-  "version": "deneb",
-  "data": {
-	"execution_payload":{
-		"parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-		"state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-		"prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"block_number": "1",
-		"gas_limit": "1",
-		"gas_used": "1",
-		"timestamp": "1",
-		"extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
-		"block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-		"transactions": [
-		  "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-		],
-		"withdrawals": [
-		  {
-			"index": "1",
-			"validator_index": "1",
-			"address": "0xcf8e0d4e9587369b2301d0790347320302cc0943",
-			"amount": "1"
-		  }
-		],
-		"blob_gas_used": "2",
- 		"excess_blob_gas": "3"
-	  },
-	"blobs_bundle": {
-      "commitments": [
-        "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
-      ],
-      "proofs": [
-        "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a",
-        "0xc00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
-      ],
-      "blobs": [
-        "%s"
-      ]
-    }
-  }
-}`, hexutil.Encode(make([]byte, fieldparams.BlobLength)))
-
 func TestExecutionPayloadResponseUnmarshal(t *testing.T) {
 	epr := &ExecPayloadResponse{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
@@ -1182,6 +1013,7 @@ func TestExecutionPayloadResponseCapellaToProto(t *testing.T) {
 		},
 	}
 	require.DeepEqual(t, expected, p)
+
 }

 func TestExecutionPayloadResponseDenebToProto(t *testing.T) {
@@ -1260,27 +1092,7 @@ func TestExecutionPayloadResponseDenebToProto(t *testing.T) {
 	}

 	require.DeepEqual(t, blobsBundle, expectedBlobs)
-}

-func TestExecutionPayloadResponseDenebToProtoInvalidBlobCount(t *testing.T) {
-	hr := &ExecPayloadResponseDeneb{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDenebTooManyBlobs), hr))
-	_, _, err := hr.ToProto()
-	require.ErrorContains(t, fmt.Sprintf("blobs length %d is more than max %d", fieldparams.MaxBlobCommitmentsPerBlock+2, fieldparams.MaxBlobCommitmentsPerBlock), err)
-}
-
-func TestExecutionPayloadResponseDenebToProtoDifferentCommitmentCount(t *testing.T) {
-	hr := &ExecPayloadResponseDeneb{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDenebDifferentCommitmentCount), hr))
-	_, _, err := hr.ToProto()
-	require.ErrorContains(t, "commitments length 2 does not equal blobs length 1", err)
-}
-
-func TestExecutionPayloadResponseDenebToProtoDifferentProofCount(t *testing.T) {
-	hr := &ExecPayloadResponseDeneb{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDenebDifferentProofCount), hr))
-	_, _, err := hr.ToProto()
-	require.ErrorContains(t, "proofs length 2 does not equal blobs length 1", err)
 }

 func pbEth1Data() *eth.Eth1Data {
@@ -1718,7 +1530,7 @@ func TestUint256UnmarshalTooBig(t *testing.T) {
 func TestMarshalBlindedBeaconBlockBodyBellatrix(t *testing.T) {
 	expected, err := os.ReadFile("testdata/blinded-block.json")
 	require.NoError(t, err)
-	b, err := structs.BlindedBeaconBlockBellatrixFromConsensus(&eth.BlindedBeaconBlockBellatrix{
+	b, err := shared.BlindedBeaconBlockBellatrixFromConsensus(&eth.BlindedBeaconBlockBellatrix{
 		Slot:          1,
 		ProposerIndex: 1,
 		ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -1748,7 +1560,7 @@ func TestMarshalBlindedBeaconBlockBodyBellatrix(t *testing.T) {
 func TestMarshalBlindedBeaconBlockBodyCapella(t *testing.T) {
 	expected, err := os.ReadFile("testdata/blinded-block-capella.json")
 	require.NoError(t, err)
-	b, err := structs.BlindedBeaconBlockCapellaFromConsensus(&eth.BlindedBeaconBlockCapella{
+	b, err := shared.BlindedBeaconBlockCapellaFromConsensus(&eth.BlindedBeaconBlockCapella{
 		Slot:          1,
 		ProposerIndex: 1,
 		ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
--- a/api/client/client_test.go
+++ b/api/client/client_test.go
@@ -4,7 +4,7 @@ import (
 	"net/url"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestValidHostname(t *testing.T) {
--- a/api/client/errors.go
+++ b/api/client/errors.go
@@ -32,7 +32,7 @@ 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.StatusNotFound:
+	case 404:
 		return errors.Wrap(ErrNotFound, msg)
 	default:
 		return errors.Wrap(ErrNotOK, msg)
--- a/api/client/validator/BUILD.bazel
+++ b/api/client/validator/BUILD.bazel
@@ -3,11 +3,12 @@ load("@prysm//tools/go:def.bzl", "go_library")
 go_library(
    name = "go_default_library",
    srcs = ["client.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/validator",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/validator",
    visibility = ["//visibility:public"],
    deps = [
        "//api/client:go_default_library",
        "//validator/rpc:go_default_library",
+        "//validator/rpc/apimiddleware:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
 )
--- a/api/client/validator/client.go
+++ b/api/client/validator/client.go
@@ -7,8 +7,9 @@ import (
 	"strings"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/validator/rpc"
+	"github.com/prysmaticlabs/prysm/v4/api/client"
+	"github.com/prysmaticlabs/prysm/v4/validator/rpc"
+	"github.com/prysmaticlabs/prysm/v4/validator/rpc/apimiddleware"
 )

 const (
@@ -41,14 +42,14 @@ func (c *Client) GetValidatorPubKeys(ctx context.Context) ([]string, error) {
 	if err != nil {
 		return nil, err
 	}
-	if len(jsonlocal.Data) == 0 && len(jsonremote.Data) == 0 {
+	if len(jsonlocal.Keystores) == 0 && len(jsonremote.Data) == 0 {
 		return nil, errors.New("there are no local keys or remote keys on the validator")
 	}

 	hexKeys := make(map[string]bool)

-	for index := range jsonlocal.Data {
-		hexKeys[jsonlocal.Data[index].ValidatingPubkey] = true
+	for index := range jsonlocal.Keystores {
+		hexKeys[jsonlocal.Keystores[index].ValidatingPubkey] = true
 	}
 	for index := range jsonremote.Data {
 		hexKeys[jsonremote.Data[index].Pubkey] = true
@@ -61,12 +62,12 @@ func (c *Client) GetValidatorPubKeys(ctx context.Context) ([]string, error) {
 }

 // GetLocalValidatorKeys calls the keymanager APIs for local validator keys
-func (c *Client) GetLocalValidatorKeys(ctx context.Context) (*rpc.ListKeystoresResponse, error) {
+func (c *Client) GetLocalValidatorKeys(ctx context.Context) (*apimiddleware.ListKeystoresResponseJson, error) {
 	localBytes, err := c.Get(ctx, localKeysPath, client.WithAuthorizationToken(c.Token()))
 	if err != nil {
 		return nil, err
 	}
-	jsonlocal := &rpc.ListKeystoresResponse{}
+	jsonlocal := &apimiddleware.ListKeystoresResponseJson{}
 	if err := json.Unmarshal(localBytes, jsonlocal); err != nil {
 		return nil, errors.Wrap(err, "failed to parse local keystore list")
 	}
--- a/api/constants.go
+++ b/api/constants.go
@@ -1,7 +0,0 @@
-package api
-
-const (
-	WebUrlPrefix        = "/v2/validator/"
-	WebApiUrlPrefix     = "/api/v2/validator/"
-	KeymanagerApiPrefix = "/eth/v1"
-)
--- a/api/gateway/BUILD.bazel
+++ b/api/gateway/BUILD.bazel
@@ -8,22 +8,22 @@ go_library(
        "modifiers.go",
        "options.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/gateway",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/gateway",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//validator:__subpackages__",
    ],
    deps = [
-        "//api/server:go_default_library",
+        "//api/gateway/apimiddleware:go_default_library",
        "//runtime:go_default_library",
        "@com_github_gorilla_mux//:go_default_library",
        "@com_github_grpc_ecosystem_grpc_gateway_v2//runtime:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_rs_cors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@org_golang_google_grpc//:go_default_library",
        "@org_golang_google_grpc//connectivity:go_default_library",
        "@org_golang_google_grpc//credentials:go_default_library",
-        "@org_golang_google_grpc//credentials/insecure:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
    ],
 )
@@ -33,6 +33,7 @@ go_test(
    srcs = ["gateway_test.go"],
    embed = [":go_default_library"],
    deps = [
+        "//api/gateway/apimiddleware:go_default_library",
        "//cmd/beacon-chain/flags:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
--- a/api/gateway/apimiddleware/BUILD.bazel
+++ b/api/gateway/apimiddleware/BUILD.bazel
@@ -0,0 +1,43 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "api_middleware.go",
+        "log.go",
+        "param_handling.go",
+        "process_field.go",
+        "process_request.go",
+        "structs.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//api:go_default_library",
+        "//api/grpc:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_gorilla_mux//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@com_github_wealdtech_go_bytesutil//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "param_handling_test.go",
+        "process_request_test.go",
+    ],
+    embed = [":go_default_library"],
+    deps = [
+        "//api:go_default_library",
+        "//api/grpc:go_default_library",
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "@com_github_gorilla_mux//:go_default_library",
+        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
+    ],
+)
--- a/api/gateway/apimiddleware/api_middleware.go
+++ b/api/gateway/apimiddleware/api_middleware.go
@@ -0,0 +1,265 @@
+package apimiddleware
+
+import (
+	"net/http"
+	"reflect"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+// ApiProxyMiddleware is a proxy between an Ethereum consensus API HTTP client and grpc-gateway.
+// The purpose of the proxy is to handle HTTP requests and gRPC responses in such a way that:
+//   - Ethereum consensus API requests can be handled by grpc-gateway correctly
+//   - gRPC responses can be returned as spec-compliant Ethereum consensus API responses
+type ApiProxyMiddleware struct {
+	GatewayAddress  string
+	EndpointCreator EndpointFactory
+	Timeout         time.Duration
+	router          *mux.Router
+}
+
+// EndpointFactory is responsible for creating new instances of Endpoint values.
+type EndpointFactory interface {
+	Create(path string) (*Endpoint, error)
+	Paths() []string
+	IsNil() bool
+}
+
+// Endpoint is a representation of an API HTTP endpoint that should be proxied by the middleware.
+type Endpoint struct {
+	Path               string          // The path of the HTTP endpoint.
+	GetResponse        interface{}     // The struct corresponding to the JSON structure used in a GET response.
+	PostRequest        interface{}     // The struct corresponding to the JSON structure used in a POST request.
+	PostResponse       interface{}     // The struct corresponding to the JSON structure used in a POST response.
+	DeleteRequest      interface{}     // The struct corresponding to the JSON structure used in a DELETE request.
+	DeleteResponse     interface{}     // The struct corresponding to the JSON structure used in a DELETE response.
+	RequestURLLiterals []string        // Names of URL parameters that should not be base64-encoded.
+	RequestQueryParams []QueryParam    // Query parameters of the request.
+	Err                ErrorJson       // The struct corresponding to the error that should be returned in case of a request failure.
+	Hooks              HookCollection  // A collection of functions that can be invoked at various stages of the request/response cycle.
+	CustomHandlers     []CustomHandler // Functions that will be executed instead of the default request/response behaviour.
+}
+
+// RunDefault expresses whether the default processing logic should be carried out after running a pre hook.
+type RunDefault bool
+
+// DefaultEndpoint returns an Endpoint with default configuration, e.g. DefaultErrorJson for error handling.
+func DefaultEndpoint() Endpoint {
+	return Endpoint{
+		Err: &DefaultErrorJson{},
+	}
+}
+
+// QueryParam represents a single query parameter's metadata.
+type QueryParam struct {
+	Name string
+	Hex  bool
+	Enum bool
+}
+
+// CustomHandler is a function that can be invoked at the very beginning of the request,
+// essentially replacing the whole default request/response logic with custom logic for a specific endpoint.
+type CustomHandler = func(m *ApiProxyMiddleware, endpoint Endpoint, w http.ResponseWriter, req *http.Request) (handled bool)
+
+// HookCollection contains hooks that can be used to amend the default request/response cycle with custom logic for a specific endpoint.
+type HookCollection struct {
+	OnPreDeserializeRequestBodyIntoContainer      func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) (RunDefault, ErrorJson)
+	OnPostDeserializeRequestBodyIntoContainer     func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson
+	OnPreDeserializeGrpcResponseBodyIntoContainer func([]byte, interface{}) (RunDefault, ErrorJson)
+	OnPreSerializeMiddlewareResponseIntoJson      func(interface{}) (RunDefault, []byte, ErrorJson)
+}
+
+// fieldProcessor applies the processing function f to a value when the tag is present on the field.
+type fieldProcessor struct {
+	tag string
+	f   func(value reflect.Value) error
+}
+
+// Run starts the proxy, registering all proxy endpoints.
+func (m *ApiProxyMiddleware) Run(gatewayRouter *mux.Router) {
+	for _, path := range m.EndpointCreator.Paths() {
+		gatewayRouter.HandleFunc(path, m.WithMiddleware(path))
+	}
+	m.router = gatewayRouter
+}
+
+// ServeHTTP for the proxy middleware.
+func (m *ApiProxyMiddleware) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	m.router.ServeHTTP(w, req)
+}
+
+// WithMiddleware wraps the given endpoint handler with the middleware logic.
+func (m *ApiProxyMiddleware) WithMiddleware(path string) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		endpoint, err := m.EndpointCreator.Create(path)
+		if err != nil {
+			log.WithError(err).Errorf("Could not create endpoint for path: %s", path)
+			return
+		}
+
+		for _, handler := range endpoint.CustomHandlers {
+			if handler(m, *endpoint, w, req) {
+				return
+			}
+		}
+
+		if req.Method == "POST" {
+			if errJson := handlePostRequestForEndpoint(endpoint, w, req); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+		}
+
+		if req.Method == "DELETE" && req.Body != http.NoBody {
+			if errJson := handleDeleteRequestForEndpoint(endpoint, req); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+		}
+
+		if errJson := m.PrepareRequestForProxying(*endpoint, req); errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+		grpcResp, errJson := m.ProxyRequest(req)
+		if errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+		grpcRespBody, errJson := ReadGrpcResponseBody(grpcResp.Body)
+		if errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+
+		var respJson []byte
+		if !GrpcResponseIsEmpty(grpcRespBody) {
+			respHasError, errJson := HandleGrpcResponseError(endpoint.Err, grpcResp, grpcRespBody, w)
+			if errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+			if respHasError {
+				return
+			}
+
+			var resp interface{}
+			if req.Method == "GET" {
+				resp = endpoint.GetResponse
+			} else if req.Method == "DELETE" {
+				resp = endpoint.DeleteResponse
+			} else {
+				resp = endpoint.PostResponse
+			}
+			if errJson := deserializeGrpcResponseBodyIntoContainerWrapped(endpoint, grpcRespBody, resp); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+			if errJson := ProcessMiddlewareResponseFields(resp); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+
+			respJson, errJson = serializeMiddlewareResponseIntoJsonWrapped(endpoint, respJson, resp)
+			if errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+		}
+
+		if errJson := WriteMiddlewareResponseHeadersAndBody(grpcResp, respJson, w); errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+		if errJson := Cleanup(grpcResp.Body); errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+	}
+}
+
+func handlePostRequestForEndpoint(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson {
+	if errJson := deserializeRequestBodyIntoContainerWrapped(endpoint, req, w); errJson != nil {
+		return errJson
+	}
+	if errJson := ProcessRequestContainerFields(endpoint.PostRequest); errJson != nil {
+		return errJson
+	}
+	return SetRequestBodyToRequestContainer(endpoint.PostRequest, req)
+}
+
+func handleDeleteRequestForEndpoint(endpoint *Endpoint, req *http.Request) ErrorJson {
+	if errJson := DeserializeRequestBodyIntoContainer(req.Body, endpoint.DeleteRequest); errJson != nil {
+		return errJson
+	}
+	if errJson := ProcessRequestContainerFields(endpoint.DeleteRequest); errJson != nil {
+		return errJson
+	}
+	return SetRequestBodyToRequestContainer(endpoint.DeleteRequest, req)
+}
+
+func deserializeRequestBodyIntoContainerWrapped(endpoint *Endpoint, req *http.Request, w http.ResponseWriter) ErrorJson {
+	runDefault := true
+	if endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer != nil {
+		run, errJson := endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer(endpoint, w, req)
+		if errJson != nil {
+			return errJson
+		}
+		if !run {
+			runDefault = false
+		}
+	}
+	if runDefault {
+		if errJson := DeserializeRequestBodyIntoContainer(req.Body, endpoint.PostRequest); errJson != nil {
+			return errJson
+		}
+	}
+	if endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer != nil {
+		if errJson := endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer(endpoint, w, req); errJson != nil {
+			return errJson
+		}
+	}
+	return nil
+}
+
+func deserializeGrpcResponseBodyIntoContainerWrapped(endpoint *Endpoint, grpcResponseBody []byte, resp interface{}) ErrorJson {
+	runDefault := true
+	if endpoint.Hooks.OnPreDeserializeGrpcResponseBodyIntoContainer != nil {
+		run, errJson := endpoint.Hooks.OnPreDeserializeGrpcResponseBodyIntoContainer(grpcResponseBody, resp)
+		if errJson != nil {
+			return errJson
+		}
+		if !run {
+			runDefault = false
+		}
+	}
+	if runDefault {
+		if errJson := DeserializeGrpcResponseBodyIntoContainer(grpcResponseBody, resp); errJson != nil {
+			return errJson
+		}
+	}
+	return nil
+}
+
+func serializeMiddlewareResponseIntoJsonWrapped(endpoint *Endpoint, respJson []byte, resp interface{}) ([]byte, ErrorJson) {
+	runDefault := true
+	var errJson ErrorJson
+	if endpoint.Hooks.OnPreSerializeMiddlewareResponseIntoJson != nil {
+		var run RunDefault
+		run, respJson, errJson = endpoint.Hooks.OnPreSerializeMiddlewareResponseIntoJson(resp)
+		if errJson != nil {
+			return nil, errJson
+		}
+		if !run {
+			runDefault = false
+		}
+	}
+	if runDefault {
+		respJson, errJson = SerializeMiddlewareResponseIntoJson(resp)
+		if errJson != nil {
+			return nil, errJson
+		}
+	}
+	return respJson, nil
+}
--- a/api/gateway/apimiddleware/log.go
+++ b/api/gateway/apimiddleware/log.go
@@ -0,0 +1,5 @@
+package apimiddleware
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "apimiddleware")
--- a/api/gateway/apimiddleware/param_handling.go
+++ b/api/gateway/apimiddleware/param_handling.go
@@ -0,0 +1,103 @@
+package apimiddleware
+
+import (
+	"encoding/base64"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/gorilla/mux"
+	butil "github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/wealdtech/go-bytesutil"
+)
+
+// HandleURLParameters processes URL parameters, allowing parameterized URLs to be safely and correctly proxied to grpc-gateway.
+func HandleURLParameters(url string, req *http.Request, literals []string) ErrorJson {
+	segments := strings.Split(url, "/")
+
+segmentsLoop:
+	for i, s := range segments {
+		// We only care about segments which are parameterized.
+		if isRequestParam(s) {
+			// Don't do anything with parameters which should be forwarded literally to gRPC.
+			for _, l := range literals {
+				if s == "{"+l+"}" {
+					continue segmentsLoop
+				}
+			}
+
+			routeVar := mux.Vars(req)[s[1:len(s)-1]]
+			bRouteVar := []byte(routeVar)
+			if butil.IsHex(bRouteVar) {
+				var err error
+				bRouteVar, err = bytesutil.FromHexString(string(bRouteVar))
+				if err != nil {
+					return InternalServerErrorWithMessage(err, "could not process URL parameter")
+				}
+			}
+			// Converting hex to base64 may result in a value which malforms the URL.
+			// We use URLEncoding to safely escape such values.
+			base64RouteVar := base64.URLEncoding.EncodeToString(bRouteVar)
+
+			// Merge segments back into the full URL.
+			splitPath := strings.Split(req.URL.Path, "/")
+			splitPath[i] = base64RouteVar
+			req.URL.Path = strings.Join(splitPath, "/")
+		}
+	}
+	return nil
+}
+
+// HandleQueryParameters processes query parameters, allowing them to be safely and correctly proxied to grpc-gateway.
+func HandleQueryParameters(req *http.Request, params []QueryParam) ErrorJson {
+	queryParams := req.URL.Query()
+
+	normalizeQueryValues(queryParams)
+
+	for key, vals := range queryParams {
+		for _, p := range params {
+			if key == p.Name {
+				if p.Hex {
+					queryParams.Del(key)
+					for _, v := range vals {
+						b := []byte(v)
+						if butil.IsHex(b) {
+							var err error
+							b, err = bytesutil.FromHexString(v)
+							if err != nil {
+								return InternalServerErrorWithMessage(err, "could not process query parameter")
+							}
+						}
+						queryParams.Add(key, base64.URLEncoding.EncodeToString(b))
+					}
+				}
+				if p.Enum {
+					queryParams.Del(key)
+					for _, v := range vals {
+						// gRPC expects uppercase enum values.
+						queryParams.Add(key, strings.ToUpper(v))
+					}
+				}
+			}
+		}
+	}
+	req.URL.RawQuery = queryParams.Encode()
+	return nil
+}
+
+// isRequestParam verifies whether the passed string is a request parameter.
+// Request parameters are enclosed in { and }.
+func isRequestParam(s string) bool {
+	return len(s) > 2 && s[0] == '{' && s[len(s)-1] == '}'
+}
+
+func normalizeQueryValues(queryParams url.Values) {
+	// Replace comma-separated values with individual values.
+	for key, vals := range queryParams {
+		splitVals := make([]string, 0)
+		for _, v := range vals {
+			splitVals = append(splitVals, strings.Split(v, ",")...)
+		}
+		queryParams[key] = splitVals
+	}
+}
--- a/api/gateway/apimiddleware/param_handling_test.go
+++ b/api/gateway/apimiddleware/param_handling_test.go
@@ -0,0 +1,124 @@
+package apimiddleware
+
+import (
+	"bytes"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gorilla/mux"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func TestHandleURLParameters(t *testing.T) {
+	var body bytes.Buffer
+
+	t.Run("no_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example/bar", &body)
+
+		errJson := HandleURLParameters("/not_param", request, []string{})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/bar", request.URL.Path)
+	})
+
+	t.Run("with_params", func(t *testing.T) {
+		muxVars := make(map[string]string)
+		muxVars["bar_param"] = "bar"
+		muxVars["quux_param"] = "quux"
+		request := httptest.NewRequest("GET", "http://foo.example/bar/baz/quux", &body)
+		request = mux.SetURLVars(request, muxVars)
+
+		errJson := HandleURLParameters("/{bar_param}/not_param/{quux_param}", request, []string{})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/YmFy/baz/cXV1eA==", request.URL.Path)
+	})
+
+	t.Run("with_literal", func(t *testing.T) {
+		muxVars := make(map[string]string)
+		muxVars["bar_param"] = "bar"
+		request := httptest.NewRequest("GET", "http://foo.example/bar/baz", &body)
+		request = mux.SetURLVars(request, muxVars)
+
+		errJson := HandleURLParameters("/{bar_param}/not_param/", request, []string{"bar_param"})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/bar/baz", request.URL.Path)
+	})
+
+	t.Run("with_hex", func(t *testing.T) {
+		muxVars := make(map[string]string)
+		muxVars["hex_param"] = "0x626172"
+		request := httptest.NewRequest("GET", "http://foo.example/0x626172/baz", &body)
+		request = mux.SetURLVars(request, muxVars)
+
+		errJson := HandleURLParameters("/{hex_param}/not_param/", request, []string{})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/YmFy/baz", request.URL.Path)
+	})
+}
+
+func TestHandleQueryParameters(t *testing.T) {
+	var body bytes.Buffer
+
+	t.Run("regular_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example?bar=bar&baz=baz", &body)
+
+		errJson := HandleQueryParameters(request, []QueryParam{{Name: "bar"}, {Name: "baz"}})
+		require.Equal(t, true, errJson == nil)
+		query := request.URL.Query()
+		v, ok := query["bar"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "bar", v[0])
+		v, ok = query["baz"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "baz", v[0])
+	})
+
+	t.Run("hex_and_enum_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example?hex=0x626172&baz=baz", &body)
+
+		errJson := HandleQueryParameters(request, []QueryParam{{Name: "hex", Hex: true}, {Name: "baz", Enum: true}})
+		require.Equal(t, true, errJson == nil)
+		query := request.URL.Query()
+		v, ok := query["hex"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "YmFy", v[0])
+		v, ok = query["baz"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "BAZ", v[0])
+	})
+}
+
+func TestIsRequestParam(t *testing.T) {
+	tests := []struct {
+		s string
+		b bool
+	}{
+		{"", false},
+		{"{", false},
+		{"}", false},
+		{"{}", false},
+		{"{x}", true},
+		{"{very_long_parameter_name_with_underscores}", true},
+	}
+	for _, tt := range tests {
+		b := isRequestParam(tt.s)
+		assert.Equal(t, tt.b, b)
+	}
+}
+
+func TestNormalizeQueryValues(t *testing.T) {
+	input := make(map[string][]string)
+	input["key"] = []string{"value1", "value2,value3,value4", "value5"}
+
+	normalizeQueryValues(input)
+	require.Equal(t, 5, len(input["key"]))
+	assert.Equal(t, "value1", input["key"][0])
+	assert.Equal(t, "value2", input["key"][1])
+	assert.Equal(t, "value3", input["key"][2])
+	assert.Equal(t, "value4", input["key"][3])
+	assert.Equal(t, "value5", input["key"][4])
+}
--- a/api/gateway/apimiddleware/process_field.go
+++ b/api/gateway/apimiddleware/process_field.go
@@ -0,0 +1,179 @@
+package apimiddleware
+
+import (
+	"encoding/base64"
+	"fmt"
+	"math/big"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
+	"github.com/wealdtech/go-bytesutil"
+)
+
+// processField calls each processor function on any field that has the matching tag set.
+// It is a recursive function.
+func processField(s interface{}, processors []fieldProcessor) error {
+	kind := reflect.TypeOf(s).Kind()
+	if kind != reflect.Ptr && kind != reflect.Slice && kind != reflect.Array {
+		return fmt.Errorf("processing fields of kind '%v' is unsupported", kind)
+	}
+
+	t := reflect.TypeOf(s).Elem()
+	v := reflect.Indirect(reflect.ValueOf(s))
+
+	for i := 0; i < t.NumField(); i++ {
+		switch v.Field(i).Kind() {
+		case reflect.Slice:
+			sliceElem := t.Field(i).Type.Elem()
+			kind := sliceElem.Kind()
+			// Recursively process slices to struct pointers.
+			switch {
+			case kind == reflect.Ptr && sliceElem.Elem().Kind() == reflect.Struct:
+				for j := 0; j < v.Field(i).Len(); j++ {
+					if err := processField(v.Field(i).Index(j).Interface(), processors); err != nil {
+						return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+					}
+				}
+			// Process each string in string slices.
+			case kind == reflect.String:
+				for _, proc := range processors {
+					_, hasTag := t.Field(i).Tag.Lookup(proc.tag)
+					if !hasTag {
+						continue
+					}
+					for j := 0; j < v.Field(i).Len(); j++ {
+						if err := proc.f(v.Field(i).Index(j)); err != nil {
+							return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+						}
+					}
+				}
+			}
+		// Recursively process struct pointers.
+		case reflect.Ptr:
+			if v.Field(i).Elem().Kind() == reflect.Struct {
+				if err := processField(v.Field(i).Interface(), processors); err != nil {
+					return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+				}
+			}
+		default:
+			field := t.Field(i)
+			for _, proc := range processors {
+				if _, hasTag := field.Tag.Lookup(proc.tag); hasTag {
+					if err := proc.f(v.Field(i)); err != nil {
+						return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func hexToBase64Processor(v reflect.Value) error {
+	if v.String() == "0x" {
+		v.SetString("")
+		return nil
+	}
+	b, err := bytesutil.FromHexString(v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(base64.StdEncoding.EncodeToString(b))
+	return nil
+}
+
+func base64ToHexProcessor(v reflect.Value) error {
+	if v.String() == "" {
+		// Empty hex values are represented as "0x".
+		v.SetString("0x")
+		return nil
+	}
+	b, err := base64.StdEncoding.DecodeString(v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(hexutil.Encode(b))
+	return nil
+}
+
+func base64ToChecksumAddressProcessor(v reflect.Value) error {
+	if v.String() == "" {
+		// Empty hex values are represented as "0x".
+		v.SetString("0x")
+		return nil
+	}
+	b, err := base64.StdEncoding.DecodeString(v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(common.BytesToAddress(b).Hex())
+	return nil
+}
+
+func base64ToUint256Processor(v reflect.Value) error {
+	if v.String() == "" {
+		return nil
+	}
+	littleEndian, err := base64.StdEncoding.DecodeString(v.String())
+	if err != nil {
+		return err
+	}
+	if len(littleEndian) != 32 {
+		return errors.New("invalid length for Uint256")
+	}
+
+	// Integers are stored as little-endian, but
+	// big.Int expects big-endian. So we need to reverse
+	// the byte order before decoding.
+	var bigEndian [32]byte
+	for i := 0; i < len(littleEndian); i++ {
+		bigEndian[i] = littleEndian[len(littleEndian)-1-i]
+	}
+	var uint256 big.Int
+	uint256.SetBytes(bigEndian[:])
+	v.SetString(uint256.String())
+	return nil
+}
+
+func uint256ToBase64Processor(v reflect.Value) error {
+	if v.String() == "" {
+		return nil
+	}
+	uint256, ok := new(big.Int).SetString(v.String(), 10)
+	if !ok {
+		return fmt.Errorf("could not parse Uint256")
+	}
+	bigEndian := uint256.Bytes()
+	if len(bigEndian) > 32 {
+		return fmt.Errorf("number too big for Uint256")
+	}
+
+	// Integers are stored as little-endian, but
+	// big.Int gives big-endian. So we need to reverse
+	// the byte order before encoding.
+	var littleEndian [32]byte
+	for i := 0; i < len(bigEndian); i++ {
+		littleEndian[i] = bigEndian[len(bigEndian)-1-i]
+	}
+	v.SetString(base64.StdEncoding.EncodeToString(littleEndian[:]))
+	return nil
+}
+
+func enumToLowercaseProcessor(v reflect.Value) error {
+	v.SetString(strings.ToLower(v.String()))
+	return nil
+}
+
+func timeToUnixProcessor(v reflect.Value) error {
+	t, err := time.Parse(time.RFC3339, v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(strconv.FormatUint(uint64(t.Unix()), 10))
+	return nil
+}
--- a/api/gateway/apimiddleware/process_request.go
+++ b/api/gateway/apimiddleware/process_request.go
@@ -0,0 +1,283 @@
+package apimiddleware
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/api"
+	"github.com/prysmaticlabs/prysm/v4/api/grpc"
+)
+
+// DeserializeRequestBodyIntoContainer deserializes the request's body into an endpoint-specific struct.
+func DeserializeRequestBodyIntoContainer(body io.Reader, requestContainer interface{}) ErrorJson {
+	decoder := json.NewDecoder(body)
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&requestContainer); err != nil {
+		if strings.Contains(err.Error(), "json: unknown field") {
+			e := errors.Wrap(err, "could not decode request body")
+			return &DefaultErrorJson{
+				Message: e.Error(),
+				Code:    http.StatusBadRequest,
+			}
+		}
+		return InternalServerErrorWithMessage(err, "could not decode request body")
+	}
+	return nil
+}
+
+// ProcessRequestContainerFields processes fields of an endpoint-specific container according to field tags.
+func ProcessRequestContainerFields(requestContainer interface{}) ErrorJson {
+	if err := processField(requestContainer, []fieldProcessor{
+		{
+			tag: "hex",
+			f:   hexToBase64Processor,
+		},
+		{
+			tag: "uint256",
+			f:   uint256ToBase64Processor,
+		},
+	}); err != nil {
+		return InternalServerErrorWithMessage(err, "could not process request data")
+	}
+	return nil
+}
+
+// SetRequestBodyToRequestContainer makes the endpoint-specific container the new body of the request.
+func SetRequestBodyToRequestContainer(requestContainer interface{}, req *http.Request) ErrorJson {
+	// Serialize the struct, which now includes a base64-encoded value, into JSON.
+	j, err := json.Marshal(requestContainer)
+	if err != nil {
+		return InternalServerErrorWithMessage(err, "could not marshal request")
+	}
+	// Set the body to the new JSON.
+	req.Body = io.NopCloser(bytes.NewReader(j))
+	req.Header.Set("Content-Length", strconv.Itoa(len(j)))
+	req.ContentLength = int64(len(j))
+	return nil
+}
+
+// PrepareRequestForProxying applies additional logic to the request so that it can be correctly proxied to grpc-gateway.
+func (m *ApiProxyMiddleware) PrepareRequestForProxying(endpoint Endpoint, req *http.Request) ErrorJson {
+	req.URL.Scheme = "http"
+	req.URL.Host = m.GatewayAddress
+	req.RequestURI = ""
+	if errJson := HandleURLParameters(endpoint.Path, req, endpoint.RequestURLLiterals); errJson != nil {
+		return errJson
+	}
+	if errJson := HandleQueryParameters(req, endpoint.RequestQueryParams); errJson != nil {
+		return errJson
+	}
+	// We have to add the prefix after handling parameters because adding the prefix changes URL segment indexing.
+	req.URL.Path = "/internal" + req.URL.Path
+	return nil
+}
+
+// ProxyRequest proxies the request to grpc-gateway.
+func (m *ApiProxyMiddleware) ProxyRequest(req *http.Request) (*http.Response, ErrorJson) {
+	// We do not use http.DefaultClient because it does not have any timeout.
+	netClient := &http.Client{Timeout: m.Timeout}
+	grpcResp, err := netClient.Do(req)
+	if err != nil {
+		if err, ok := err.(net.Error); ok && err.Timeout() {
+			return nil, TimeoutError()
+		}
+		return nil, InternalServerErrorWithMessage(err, "could not proxy request")
+	}
+	if grpcResp == nil {
+		return nil, &DefaultErrorJson{Message: "nil response from gRPC-gateway", Code: http.StatusInternalServerError}
+	}
+	return grpcResp, nil
+}
+
+// ReadGrpcResponseBody reads the body from the grpc-gateway's response.
+func ReadGrpcResponseBody(r io.Reader) ([]byte, ErrorJson) {
+	body, err := io.ReadAll(r)
+	if err != nil {
+		return nil, InternalServerErrorWithMessage(err, "could not read response body")
+	}
+	return body, nil
+}
+
+// HandleGrpcResponseError acts on an error that resulted from a grpc-gateway's response.
+// Whether there was an error is indicated by the bool return value. In case of an error,
+// there is no need to write to the response because it's taken care of by the function.
+func HandleGrpcResponseError(errJson ErrorJson, resp *http.Response, respBody []byte, w http.ResponseWriter) (bool, ErrorJson) {
+	responseHasError := false
+	if err := json.Unmarshal(respBody, errJson); err != nil {
+		return false, InternalServerErrorWithMessage(err, "could not unmarshal error")
+	}
+	if errJson.Msg() != "" {
+		responseHasError = true
+		// Something went wrong, but the request completed, meaning we can write headers and the error message.
+		for h, vs := range resp.Header {
+			for _, v := range vs {
+				if strings.HasSuffix(h, api.VersionHeader) {
+					w.Header().Set(api.VersionHeader, v)
+				} else {
+					w.Header().Set(h, v)
+				}
+			}
+		}
+		// Handle gRPC timeout.
+		if resp.StatusCode == http.StatusGatewayTimeout {
+			WriteError(w, TimeoutError(), resp.Header)
+		} else {
+			// Set code to HTTP code because unmarshalled body contained gRPC code.
+			errJson.SetCode(resp.StatusCode)
+			WriteError(w, errJson, resp.Header)
+		}
+	}
+	return responseHasError, nil
+}
+
+// GrpcResponseIsEmpty determines whether the grpc-gateway's response body contains no data.
+func GrpcResponseIsEmpty(grpcResponseBody []byte) bool {
+	return len(grpcResponseBody) == 0 || string(grpcResponseBody) == "{}"
+}
+
+// DeserializeGrpcResponseBodyIntoContainer deserializes the grpc-gateway's response body into an endpoint-specific struct.
+func DeserializeGrpcResponseBodyIntoContainer(body []byte, responseContainer interface{}) ErrorJson {
+	if err := json.Unmarshal(body, &responseContainer); err != nil {
+		return InternalServerErrorWithMessage(err, "could not unmarshal response")
+	}
+	return nil
+}
+
+// ProcessMiddlewareResponseFields processes fields of an endpoint-specific container according to field tags.
+func ProcessMiddlewareResponseFields(responseContainer interface{}) ErrorJson {
+	if err := processField(responseContainer, []fieldProcessor{
+		{
+			tag: "hex",
+			f:   base64ToHexProcessor,
+		},
+		{
+			tag: "address",
+			f:   base64ToChecksumAddressProcessor,
+		},
+		{
+			tag: "enum",
+			f:   enumToLowercaseProcessor,
+		},
+		{
+			tag: "time",
+			f:   timeToUnixProcessor,
+		},
+		{
+			tag: "uint256",
+			f:   base64ToUint256Processor,
+		},
+	}); err != nil {
+		return InternalServerErrorWithMessage(err, "could not process response data")
+	}
+	return nil
+}
+
+// SerializeMiddlewareResponseIntoJson serializes the endpoint-specific response struct into a JSON representation.
+func SerializeMiddlewareResponseIntoJson(responseContainer interface{}) (jsonResponse []byte, errJson ErrorJson) {
+	j, err := json.Marshal(responseContainer)
+	if err != nil {
+		return nil, InternalServerErrorWithMessage(err, "could not marshal response")
+	}
+	return j, nil
+}
+
+// WriteMiddlewareResponseHeadersAndBody populates headers and the body of the final response.
+func WriteMiddlewareResponseHeadersAndBody(grpcResp *http.Response, responseJson []byte, w http.ResponseWriter) ErrorJson {
+	var statusCodeHeader string
+	for h, vs := range grpcResp.Header {
+		// We don't want to expose any gRPC metadata in the HTTP response, so we skip forwarding metadata headers.
+		if strings.HasPrefix(h, grpc.MetadataPrefix) {
+			if h == grpc.WithPrefix(grpc.HttpCodeMetadataKey) {
+				statusCodeHeader = vs[0]
+			} else if strings.HasSuffix(h, api.VersionHeader) {
+				w.Header().Set(api.VersionHeader, vs[0])
+			}
+		} else {
+			for _, v := range vs {
+				w.Header().Set(h, v)
+			}
+		}
+	}
+	if !GrpcResponseIsEmpty(responseJson) {
+		w.Header().Set("Content-Length", strconv.Itoa(len(responseJson)))
+		if statusCodeHeader != "" {
+			code, err := strconv.Atoi(statusCodeHeader)
+			if err != nil {
+				return InternalServerErrorWithMessage(err, "could not parse status code")
+			}
+			w.WriteHeader(code)
+		} else {
+			w.WriteHeader(grpcResp.StatusCode)
+		}
+		if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(responseJson))); err != nil {
+			return InternalServerErrorWithMessage(err, "could not write response message")
+		}
+	} else {
+		w.Header().Set("Content-Length", "0")
+		w.WriteHeader(grpcResp.StatusCode)
+	}
+	return nil
+}
+
+// WriteError writes the error by manipulating headers and the body of the final response.
+func WriteError(w http.ResponseWriter, errJson ErrorJson, responseHeader http.Header) {
+	// Include custom error in the error JSON.
+	hasCustomError := false
+	if responseHeader != nil {
+		customError, ok := responseHeader[grpc.WithPrefix(grpc.CustomErrorMetadataKey)]
+		if ok {
+			hasCustomError = true
+			// Assume header has only one value and read the 0 index.
+			if err := json.Unmarshal([]byte(customError[0]), errJson); err != nil {
+				log.WithError(err).Error("Could not unmarshal custom error message")
+				return
+			}
+		}
+	}
+
+	var j []byte
+	if hasCustomError {
+		var err error
+		j, err = json.Marshal(errJson)
+		if err != nil {
+			log.WithError(err).Error("Could not marshal error message")
+			return
+		}
+	} else {
+		var err error
+		// We marshal the response body into a DefaultErrorJson if the custom error is not present.
+		// This is because the ErrorJson argument is the endpoint's error definition, which may contain custom fields.
+		// In such a scenario marhaling the endpoint's error would populate the resulting JSON
+		// with these fields even if they are not present in the gRPC header.
+		d := &DefaultErrorJson{
+			Message: errJson.Msg(),
+			Code:    errJson.StatusCode(),
+		}
+		j, err = json.Marshal(d)
+		if err != nil {
+			log.WithError(err).Error("Could not marshal error message")
+			return
+		}
+	}
+
+	w.Header().Set("Content-Length", strconv.Itoa(len(j)))
+	w.Header().Set("Content-Type", "application/json")
+	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")
+	}
+}
+
+// Cleanup performs final cleanup on the initial response from grpc-gateway.
+func Cleanup(grpcResponseBody io.ReadCloser) ErrorJson {
+	if err := grpcResponseBody.Close(); err != nil {
+		return InternalServerErrorWithMessage(err, "could not close response body")
+	}
+	return nil
+}
--- a/api/gateway/apimiddleware/process_request_test.go
+++ b/api/gateway/apimiddleware/process_request_test.go
@@ -0,0 +1,435 @@
+package apimiddleware
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/api"
+	"github.com/prysmaticlabs/prysm/v4/api/grpc"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/sirupsen/logrus/hooks/test"
+)
+
+type testRequestContainer struct {
+	TestString         string
+	TestHexString      string `hex:"true"`
+	TestEmptyHexString string `hex:"true"`
+	TestUint256String  string `uint256:"true"`
+}
+
+func defaultRequestContainer() *testRequestContainer {
+	return &testRequestContainer{
+		TestString:         "test string",
+		TestHexString:      "0x666F6F", // hex encoding of "foo"
+		TestEmptyHexString: "0x",
+		TestUint256String:  "4196",
+	}
+}
+
+type testResponseContainer struct {
+	TestString       string
+	TestHex          string `hex:"true"`
+	TestEmptyHex     string `hex:"true"`
+	TestAddress      string `address:"true"`
+	TestEmptyAddress string `address:"true"`
+	TestUint256      string `uint256:"true"`
+	TestEnum         string `enum:"true"`
+	TestTime         string `time:"true"`
+}
+
+func defaultResponseContainer() *testResponseContainer {
+	return &testResponseContainer{
+		TestString:       "test string",
+		TestHex:          "Zm9v", // base64 encoding of "foo"
+		TestEmptyHex:     "",
+		TestAddress:      "Zm9v",
+		TestEmptyAddress: "",
+		TestEnum:         "Test Enum",
+		TestTime:         "2006-01-02T15:04:05Z",
+
+		// base64 encoding of 4196 in little-endian
+		TestUint256: "ZBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
+	}
+}
+
+type testErrorJson struct {
+	Message     string
+	Code        int
+	CustomField string
+}
+
+// StatusCode returns the error's underlying error code.
+func (e *testErrorJson) StatusCode() int {
+	return e.Code
+}
+
+// Msg returns the error's underlying message.
+func (e *testErrorJson) Msg() string {
+	return e.Message
+}
+
+// SetCode sets the error's underlying error code.
+func (e *testErrorJson) SetCode(code int) {
+	e.Code = code
+}
+
+// SetMsg sets the error's underlying message.
+func (e *testErrorJson) SetMsg(msg string) {
+	e.Message = msg
+}
+
+func TestDeserializeRequestBodyIntoContainer(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		err := json.NewEncoder(&bodyJson).Encode(defaultRequestContainer())
+		require.NoError(t, err)
+
+		container := &testRequestContainer{}
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "test string", container.TestString)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("foo"))
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+
+	t.Run("unknown field", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("{\"foo\":\"foo\"}"))
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
+		assert.Equal(t, http.StatusBadRequest, errJson.StatusCode())
+	})
+}
+
+func TestProcessRequestContainerFields(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		container := defaultRequestContainer()
+
+		errJson := ProcessRequestContainerFields(container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "Zm9v", container.TestHexString)
+		assert.Equal(t, "", container.TestEmptyHexString)
+		assert.Equal(t, "ZBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=", container.TestUint256String)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		errJson := ProcessRequestContainerFields("foo")
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not process request data"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+}
+
+func TestSetRequestBodyToRequestContainer(t *testing.T) {
+	var body bytes.Buffer
+	request := httptest.NewRequest("GET", "http://foo.example", &body)
+
+	errJson := SetRequestBodyToRequestContainer(defaultRequestContainer(), request)
+	require.Equal(t, true, errJson == nil)
+	container := &testRequestContainer{}
+	require.NoError(t, json.NewDecoder(request.Body).Decode(container))
+	assert.Equal(t, "test string", container.TestString)
+	contentLengthHeader, ok := request.Header["Content-Length"]
+	require.Equal(t, true, ok)
+	require.Equal(t, 1, len(contentLengthHeader), "wrong number of header values")
+	assert.Equal(t, "108", contentLengthHeader[0])
+	assert.Equal(t, int64(108), request.ContentLength)
+}
+
+func TestPrepareRequestForProxying(t *testing.T) {
+	middleware := &ApiProxyMiddleware{
+		GatewayAddress: "http://gateway.example",
+	}
+	// We will set some params to make the request more interesting.
+	endpoint := Endpoint{
+		Path:               "/{url_param}",
+		RequestURLLiterals: []string{"url_param"},
+		RequestQueryParams: []QueryParam{{Name: "query_param"}},
+	}
+	var body bytes.Buffer
+	request := httptest.NewRequest("GET", "http://foo.example?query_param=bar", &body)
+
+	errJson := middleware.PrepareRequestForProxying(endpoint, request)
+	require.Equal(t, true, errJson == nil)
+	assert.Equal(t, "http", request.URL.Scheme)
+	assert.Equal(t, middleware.GatewayAddress, request.URL.Host)
+	assert.Equal(t, "", request.RequestURI)
+}
+
+func TestReadGrpcResponseBody(t *testing.T) {
+	var b bytes.Buffer
+	b.Write([]byte("foo"))
+
+	body, jsonErr := ReadGrpcResponseBody(&b)
+	require.Equal(t, true, jsonErr == nil)
+	assert.Equal(t, "foo", string(body))
+}
+
+func TestHandleGrpcResponseError(t *testing.T) {
+	response := &http.Response{
+		StatusCode: 400,
+		Header: http.Header{
+			"Foo": []string{"foo"},
+			"Bar": []string{"bar"},
+		},
+	}
+	writer := httptest.NewRecorder()
+	errJson := &testErrorJson{
+		Message: "foo",
+		Code:    400,
+	}
+	b, err := json.Marshal(errJson)
+	require.NoError(t, err)
+
+	hasError, e := HandleGrpcResponseError(errJson, response, b, writer)
+	require.Equal(t, true, e == nil)
+	assert.Equal(t, true, hasError)
+	v, ok := writer.Header()["Foo"]
+	require.Equal(t, true, ok, "header not found")
+	require.Equal(t, 1, len(v), "wrong number of header values")
+	assert.Equal(t, "foo", v[0])
+	v, ok = writer.Header()["Bar"]
+	require.Equal(t, true, ok, "header not found")
+	require.Equal(t, 1, len(v), "wrong number of header values")
+	assert.Equal(t, "bar", v[0])
+	assert.Equal(t, 400, errJson.StatusCode())
+}
+
+func TestGrpcResponseIsEmpty(t *testing.T) {
+	t.Run("nil", func(t *testing.T) {
+		assert.Equal(t, true, GrpcResponseIsEmpty(nil))
+	})
+	t.Run("empty_slice", func(t *testing.T) {
+		assert.Equal(t, true, GrpcResponseIsEmpty(make([]byte, 0)))
+	})
+	t.Run("empty_brackets", func(t *testing.T) {
+		assert.Equal(t, true, GrpcResponseIsEmpty([]byte("{}")))
+	})
+	t.Run("non_empty", func(t *testing.T) {
+		assert.Equal(t, false, GrpcResponseIsEmpty([]byte("{\"foo\":\"bar\"})")))
+	})
+}
+
+func TestDeserializeGrpcResponseBodyIntoContainer(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		body, err := json.Marshal(defaultRequestContainer())
+		require.NoError(t, err)
+
+		container := &testRequestContainer{}
+		errJson := DeserializeGrpcResponseBodyIntoContainer(body, container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "test string", container.TestString)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("foo"))
+		errJson := DeserializeGrpcResponseBodyIntoContainer(bodyJson.Bytes(), &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not unmarshal response"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+}
+
+func TestProcessMiddlewareResponseFields(t *testing.T) {
+	t.Run("Ok", func(t *testing.T) {
+		container := defaultResponseContainer()
+
+		errJson := ProcessMiddlewareResponseFields(container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "0x666f6f", container.TestHex)
+		assert.Equal(t, "0x", container.TestEmptyHex)
+		assert.Equal(t, "0x0000000000000000000000000000000000666F6f", container.TestAddress)
+		assert.Equal(t, "0x", container.TestEmptyAddress)
+		assert.Equal(t, "4196", container.TestUint256)
+		assert.Equal(t, "test enum", container.TestEnum)
+		assert.Equal(t, "1136214245", container.TestTime)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		errJson := ProcessMiddlewareResponseFields("foo")
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not process response data"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+}
+
+func TestSerializeMiddlewareResponseIntoJson(t *testing.T) {
+	container := defaultResponseContainer()
+	j, errJson := SerializeMiddlewareResponseIntoJson(container)
+	assert.Equal(t, true, errJson == nil)
+	cToDeserialize := &testResponseContainer{}
+	require.NoError(t, json.Unmarshal(j, cToDeserialize))
+	assert.Equal(t, "test string", cToDeserialize.TestString)
+}
+
+func TestWriteMiddlewareResponseHeadersAndBody(t *testing.T) {
+	t.Run("GET", func(t *testing.T) {
+		response := &http.Response{
+			Header: http.Header{
+				"Foo": []string{"foo"},
+				grpc.WithPrefix(grpc.HttpCodeMetadataKey): []string{"204"},
+				grpc.WithPrefix(api.VersionHeader):        []string{"capella"},
+			},
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		v, ok := writer.Header()["Foo"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "foo", v[0])
+		v, ok = writer.Header()["Content-Length"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "224", v[0])
+		v, ok = writer.Header()["Eth-Consensus-Version"]
+		require.Equal(t, true, ok, "header not found")
+		assert.Equal(t, "capella", v[0])
+		assert.Equal(t, 204, writer.Code)
+		assert.DeepEqual(t, responseJson, writer.Body.Bytes())
+	})
+
+	t.Run("GET_no_grpc_status_code_header", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+	})
+
+	t.Run("GET_invalid_status_code", func(t *testing.T) {
+		response := &http.Response{
+			Header: http.Header{"Grpc-Metadata-Eth-Consensus-Version": []string{"capella"}},
+		}
+
+		// Set invalid status code.
+		response.Header[grpc.WithPrefix(grpc.HttpCodeMetadataKey)] = []string{"invalid"}
+		response.Header[grpc.WithPrefix(api.VersionHeader)] = []string{"capella"}
+
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, false, errJson == nil)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not parse status code"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+
+	t.Run("POST", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+	})
+
+	t.Run("POST_with_response_body", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+		assert.DeepEqual(t, responseJson, writer.Body.Bytes())
+	})
+
+	t.Run("POST_with_empty_json_body", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		responseJson, err := json.Marshal(struct{}{})
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+		assert.DeepEqual(t, []byte(nil), writer.Body.Bytes())
+		assert.Equal(t, "0", writer.Header()["Content-Length"][0])
+	})
+}
+
+func TestWriteError(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		responseHeader := http.Header{
+			grpc.WithPrefix(grpc.CustomErrorMetadataKey): []string{"{\"CustomField\":\"bar\"}"},
+		}
+		errJson := &testErrorJson{
+			Message: "foo",
+			Code:    500,
+		}
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		WriteError(writer, errJson, responseHeader)
+		v, ok := writer.Header()["Content-Length"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "48", v[0])
+		v, ok = writer.Header()["Content-Type"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "application/json", v[0])
+		assert.Equal(t, 500, writer.Code)
+		eDeserialize := &testErrorJson{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), eDeserialize))
+		assert.Equal(t, "foo", eDeserialize.Message)
+		assert.Equal(t, 500, eDeserialize.Code)
+		assert.Equal(t, "bar", eDeserialize.CustomField)
+	})
+
+	t.Run("invalid_custom_error_header", func(t *testing.T) {
+		logHook := test.NewGlobal()
+
+		responseHeader := http.Header{
+			grpc.WithPrefix(grpc.CustomErrorMetadataKey): []string{"invalid"},
+		}
+
+		WriteError(httptest.NewRecorder(), &testErrorJson{}, responseHeader)
+		assert.LogsContain(t, logHook, "Could not unmarshal custom error message")
+	})
+}
--- a/api/gateway/apimiddleware/structs.go
+++ b/api/gateway/apimiddleware/structs.go
@@ -0,0 +1,69 @@
+package apimiddleware
+
+import (
+	"net/http"
+
+	"github.com/pkg/errors"
+)
+
+// ---------------
+// Error handling.
+// ---------------
+
+// ErrorJson describes common functionality of all JSON error representations.
+type ErrorJson interface {
+	StatusCode() int
+	SetCode(code int)
+	Msg() string
+	SetMsg(msg string)
+}
+
+// DefaultErrorJson is a JSON representation of a simple error value, containing only a message and an error code.
+type DefaultErrorJson struct {
+	Message string `json:"message"`
+	Code    int    `json:"code"`
+}
+
+// InternalServerErrorWithMessage returns a DefaultErrorJson with 500 code and a custom message.
+func InternalServerErrorWithMessage(err error, message string) *DefaultErrorJson {
+	e := errors.Wrapf(err, message)
+	return &DefaultErrorJson{
+		Message: e.Error(),
+		Code:    http.StatusInternalServerError,
+	}
+}
+
+// InternalServerError returns a DefaultErrorJson with 500 code.
+func InternalServerError(err error) *DefaultErrorJson {
+	return &DefaultErrorJson{
+		Message: err.Error(),
+		Code:    http.StatusInternalServerError,
+	}
+}
+
+func TimeoutError() *DefaultErrorJson {
+	return &DefaultErrorJson{
+		Message: "Request timeout",
+		Code:    http.StatusRequestTimeout,
+	}
+}
+
+// StatusCode returns the error's underlying error code.
+func (e *DefaultErrorJson) StatusCode() int {
+	return e.Code
+}
+
+// Msg returns the error's underlying message.
+func (e *DefaultErrorJson) Msg() string {
+	return e.Message
+}
+
+// SetCode sets the error's underlying error code.
+func (e *DefaultErrorJson) SetCode(code int) {
+	e.Code = code
+}
+
+// SetMsg sets the error's underlying message.
+func (e *DefaultErrorJson) SetMsg(msg string) {
+	e.Message = msg
+}
--- a/api/gateway/gateway.go
+++ b/api/gateway/gateway.go
@@ -6,17 +6,19 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"path"
+	"strings"
 	"time"

 	"github.com/gorilla/mux"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api/server"
-	"github.com/prysmaticlabs/prysm/v5/runtime"
+	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/v4/runtime"
+	"github.com/rs/cors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
-	"google.golang.org/grpc/credentials/insecure"
 )

 var _ runtime.Service = (*Gateway)(nil)
@@ -33,6 +35,7 @@ type PbHandlerRegistration func(context.Context, *gwruntime.ServeMux, *grpc.Clie

 // MuxHandler is a function that implements the mux handler functionality.
 type MuxHandler func(
+	apiMiddlewareHandler *apimiddleware.ApiProxyMiddleware,
 	h http.HandlerFunc,
 	w http.ResponseWriter,
 	req *http.Request,
@@ -40,15 +43,16 @@ type MuxHandler func(

 // Config parameters for setting up the gateway service.
 type config struct {
-	maxCallRecvMsgSize uint64
-	remoteCert         string
-	gatewayAddr        string
-	remoteAddr         string
-	allowedOrigins     []string
-	muxHandler         MuxHandler
-	pbHandlers         []*PbMux
-	router             *mux.Router
-	timeout            time.Duration
+	maxCallRecvMsgSize           uint64
+	remoteCert                   string
+	gatewayAddr                  string
+	remoteAddr                   string
+	allowedOrigins               []string
+	apiMiddlewareEndpointFactory apimiddleware.EndpointFactory
+	muxHandler                   MuxHandler
+	pbHandlers                   []*PbMux
+	router                       *mux.Router
+	timeout                      time.Duration
 }

 // Gateway is the gRPC gateway to serve HTTP JSON traffic as a proxy and forward it to the gRPC server.
@@ -57,6 +61,7 @@ type Gateway struct {
 	conn         *grpc.ClientConn
 	server       *http.Server
 	cancel       context.CancelFunc
+	proxy        *apimiddleware.ApiProxyMiddleware
 	ctx          context.Context
 	startFailure error
 }
@@ -104,11 +109,15 @@ func (g *Gateway) Start() {
 		}
 	}

-	corsMux := server.CorsHandler(g.cfg.allowedOrigins).Middleware(g.cfg.router)
+	corsMux := g.corsMiddleware(g.cfg.router)
+
+	if g.cfg.apiMiddlewareEndpointFactory != nil && !g.cfg.apiMiddlewareEndpointFactory.IsNil() {
+		g.registerApiMiddleware()
+	}

 	if g.cfg.muxHandler != nil {
 		g.cfg.router.PathPrefix("/").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			g.cfg.muxHandler(corsMux.ServeHTTP, w, r)
+			g.cfg.muxHandler(g.proxy, corsMux.ServeHTTP, w, r)
 		})
 	}

@@ -158,6 +167,35 @@ func (g *Gateway) Stop() error {
 	return nil
 }

+func (g *Gateway) corsMiddleware(h http.Handler) http.Handler {
+	c := cors.New(cors.Options{
+		AllowedOrigins:   g.cfg.allowedOrigins,
+		AllowedMethods:   []string{http.MethodPost, http.MethodGet, http.MethodDelete, http.MethodOptions},
+		AllowCredentials: true,
+		MaxAge:           600,
+		AllowedHeaders:   []string{"*"},
+	})
+	return c.Handler(h)
+}
+
+const swaggerDir = "proto/prysm/v1alpha1/"
+
+// SwaggerServer returns swagger specification files located under "/swagger/"
+func SwaggerServer() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !strings.HasSuffix(r.URL.Path, ".swagger.json") {
+			log.Debugf("Not found: %s", r.URL.Path)
+			http.NotFound(w, r)
+			return
+		}
+
+		log.Debugf("Serving %s\n", r.URL.Path)
+		p := strings.TrimPrefix(r.URL.Path, "/swagger/")
+		p = path.Join(swaggerDir, p)
+		http.ServeFile(w, r, p)
+	}
+}
+
 // dial the gRPC server.
 func (g *Gateway) dial(ctx context.Context, network, addr string) (*grpc.ClientConn, error) {
 	switch network {
@@ -173,21 +211,19 @@ func (g *Gateway) dial(ctx context.Context, network, addr string) (*grpc.ClientC
 // dialTCP creates a client connection via TCP.
 // "addr" must be a valid TCP address with a port number.
 func (g *Gateway) dialTCP(ctx context.Context, addr string) (*grpc.ClientConn, error) {
-	var security grpc.DialOption
+	security := grpc.WithInsecure()
 	if len(g.cfg.remoteCert) > 0 {
 		creds, err := credentials.NewClientTLSFromFile(g.cfg.remoteCert, "")
 		if err != nil {
 			return nil, err
 		}
 		security = grpc.WithTransportCredentials(creds)
-	} else {
-		// Use insecure credentials when there's no remote cert provided.
-		security = grpc.WithTransportCredentials(insecure.NewCredentials())
 	}
 	opts := []grpc.DialOption{
 		security,
 		grpc.WithDefaultCallOptions(grpc.MaxCallRecvMsgSize(int(g.cfg.maxCallRecvMsgSize))),
 	}
+
 	return grpc.DialContext(ctx, addr, opts...)
 }

@@ -204,9 +240,19 @@ func (g *Gateway) dialUnix(ctx context.Context, addr string) (*grpc.ClientConn,
 		return d(addr, 0)
 	}
 	opts := []grpc.DialOption{
-		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithInsecure(),
 		grpc.WithContextDialer(f),
 		grpc.WithDefaultCallOptions(grpc.MaxCallRecvMsgSize(int(g.cfg.maxCallRecvMsgSize))),
 	}
 	return grpc.DialContext(ctx, addr, opts...)
 }
+
+func (g *Gateway) registerApiMiddleware() {
+	g.proxy = &apimiddleware.ApiProxyMiddleware{
+		GatewayAddress:  g.cfg.gatewayAddr,
+		EndpointCreator: g.cfg.apiMiddlewareEndpointFactory,
+		Timeout:         g.cfg.timeout,
+	}
+	log.Info("Starting API middleware")
+	g.proxy.Run(g.cfg.router)
+}
--- a/api/gateway/gateway_test.go
+++ b/api/gateway/gateway_test.go
@@ -10,25 +10,44 @@ import (
 	"testing"

 	"github.com/gorilla/mux"
-	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"github.com/urfave/cli/v2"
 )

+type mockEndpointFactory struct {
+}
+
+func (*mockEndpointFactory) Paths() []string {
+	return []string{}
+}
+
+func (*mockEndpointFactory) Create(_ string) (*apimiddleware.Endpoint, error) {
+	return nil, nil
+}
+
+func (*mockEndpointFactory) IsNil() bool {
+	return false
+}
+
 func TestGateway_Customized(t *testing.T) {
 	r := mux.NewRouter()
 	cert := "cert"
 	origins := []string{"origin"}
 	size := uint64(100)
+	endpointFactory := &mockEndpointFactory{}

 	opts := []Option{
 		WithRouter(r),
 		WithRemoteCert(cert),
 		WithAllowedOrigins(origins),
 		WithMaxCallRecvMsgSize(size),
+		WithApiMiddleware(endpointFactory),
 		WithMuxHandler(func(
+			_ *apimiddleware.ApiProxyMiddleware,
 			_ http.HandlerFunc,
 			_ http.ResponseWriter,
 			_ *http.Request,
@@ -44,6 +63,7 @@ func TestGateway_Customized(t *testing.T) {
 	require.Equal(t, 1, len(g.cfg.allowedOrigins))
 	assert.Equal(t, origins[0], g.cfg.allowedOrigins[0])
 	assert.Equal(t, size, g.cfg.maxCallRecvMsgSize)
+	assert.Equal(t, endpointFactory, g.cfg.apiMiddlewareEndpointFactory)
 }

 func TestGateway_StartStop(t *testing.T) {
@@ -63,6 +83,7 @@ func TestGateway_StartStop(t *testing.T) {
 		WithGatewayAddr(gatewayAddress),
 		WithRemoteAddr(selfAddress),
 		WithMuxHandler(func(
+			_ *apimiddleware.ApiProxyMiddleware,
 			_ http.HandlerFunc,
 			_ http.ResponseWriter,
 			_ *http.Request,
--- a/api/gateway/options.go
+++ b/api/gateway/options.go
@@ -5,6 +5,7 @@ import (

 	"github.com/gorilla/mux"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
 )

 type Option func(g *Gateway) error
@@ -69,6 +70,14 @@ func WithMaxCallRecvMsgSize(size uint64) Option {
 	}
 }

+// WithApiMiddleware allows adding an API middleware proxy to the gateway.
+func WithApiMiddleware(endpointFactory apimiddleware.EndpointFactory) Option {
+	return func(g *Gateway) error {
+		g.cfg.apiMiddlewareEndpointFactory = endpointFactory
+		return nil
+	}
+}
+
 // WithTimeout allows changing the timeout value for API calls.
 func WithTimeout(seconds uint64) Option {
 	return func(g *Gateway) error {
--- a/api/grpc/BUILD.bazel
+++ b/api/grpc/BUILD.bazel
@@ -6,7 +6,7 @@ go_library(
        "grpcutils.go",
        "parameters.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/grpc",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/grpc",
    visibility = ["//visibility:public"],
    deps = [
        "@com_github_sirupsen_logrus//:go_default_library",
--- a/api/grpc/grpcutils_test.go
+++ b/api/grpc/grpcutils_test.go
@@ -7,8 +7,8 @@ import (
 	"testing"

 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/metadata"
--- a/api/headers.go
+++ b/api/headers.go
@@ -7,6 +7,4 @@ const (
 	ConsensusBlockValueHeader     = "Eth-Consensus-Block-Value"
 	JsonMediaType                 = "application/json"
 	OctetStreamMediaType          = "application/octet-stream"
-	EventStreamMediaType          = "text/event-stream"
-	KeepAlive                     = "keep-alive"
 )
--- a/api/pagination/BUILD.bazel
+++ b/api/pagination/BUILD.bazel
@@ -3,7 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = ["pagination.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/pagination",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/pagination",
    visibility = ["//visibility:public"],
    deps = [
        "//config/params:go_default_library",
--- a/api/pagination/pagination.go
+++ b/api/pagination/pagination.go
@@ -6,7 +6,7 @@ import (
 	"strconv"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
 )

 // StartAndEndPage takes in the requested page token, wanted page size, total page size.
--- a/api/pagination/pagination_test.go
+++ b/api/pagination/pagination_test.go
@@ -3,9 +3,9 @@ package pagination_test
 import (
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/api/pagination"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/api/pagination"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestStartAndEndPage(t *testing.T) {
--- a/api/server/BUILD.bazel
+++ b/api/server/BUILD.bazel
@@ -3,22 +3,16 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = [
-        "error.go",
        "middleware.go",
        "util.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/server",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/server",
    visibility = ["//visibility:public"],
-    deps = [
-        "@com_github_gorilla_mux//:go_default_library",
-        "@com_github_rs_cors//:go_default_library",
-    ],
 )

 go_test(
    name = "go_default_test",
    srcs = [
-        "error_test.go",
        "middleware_test.go",
        "util_test.go",
    ],
--- a/api/server/error.go
+++ b/api/server/error.go
@@ -1,45 +0,0 @@
-package server
-
-import (
-	"fmt"
-	"strings"
-)
-
-// DecodeError represents an error resulting from trying to decode an HTTP request.
-// It tracks the full field name for which decoding failed.
-type DecodeError struct {
-	path []string
-	err  error
-}
-
-// NewDecodeError wraps an error (either the initial decoding error or another DecodeError).
-// The current field that failed decoding must be passed in.
-func NewDecodeError(err error, field string) *DecodeError {
-	de, ok := err.(*DecodeError)
-	if ok {
-		return &DecodeError{path: append([]string{field}, de.path...), err: de.err}
-	}
-	return &DecodeError{path: []string{field}, err: err}
-}
-
-// Error returns the formatted error message which contains the full field name and the actual decoding error.
-func (e *DecodeError) Error() string {
-	return fmt.Sprintf("could not decode %s: %s", strings.Join(e.path, "."), e.err.Error())
-}
-
-// IndexedVerificationFailureError wraps a collection of verification failures.
-type IndexedVerificationFailureError struct {
-	Message  string                        `json:"message"`
-	Code     int                           `json:"code"`
-	Failures []*IndexedVerificationFailure `json:"failures"`
-}
-
-func (e *IndexedVerificationFailureError) StatusCode() int {
-	return e.Code
-}
-
-// IndexedVerificationFailure represents an issue when verifying a single indexed object e.g. an item in an array.
-type IndexedVerificationFailure struct {
-	Index   int    `json:"index"`
-	Message string `json:"message"`
-}
--- a/api/server/error_test.go
+++ b/api/server/error_test.go
@@ -1,16 +0,0 @@
-package server
-
-import (
-	"errors"
-	"testing"
-
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-)
-
-func TestDecodeError(t *testing.T) {
-	e := errors.New("not a number")
-	de := NewDecodeError(e, "Z")
-	de = NewDecodeError(de, "Y")
-	de = NewDecodeError(de, "X")
-	assert.Equal(t, "could not decode X.Y.Z: not a number", de.Error())
-}
--- a/api/server/middleware.go
+++ b/api/server/middleware.go
@@ -2,12 +2,8 @@ package server

 import (
 	"net/http"
-
-	"github.com/gorilla/mux"
-	"github.com/rs/cors"
 )

-// NormalizeQueryValuesHandler normalizes an input query of "key=value1,value2,value3" to "key=value1&key=value2&key=value3"
 func NormalizeQueryValuesHandler(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		query := r.URL.Query()
@@ -17,16 +13,3 @@ func NormalizeQueryValuesHandler(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
-
-// CorsHandler sets the cors settings on api endpoints
-func CorsHandler(allowOrigins []string) mux.MiddlewareFunc {
-	c := cors.New(cors.Options{
-		AllowedOrigins:   allowOrigins,
-		AllowedMethods:   []string{http.MethodPost, http.MethodGet, http.MethodDelete, http.MethodOptions},
-		AllowCredentials: true,
-		MaxAge:           600,
-		AllowedHeaders:   []string{"*"},
-	})
-
-	return c.Handler
-}
--- a/api/server/middleware_test.go
+++ b/api/server/middleware_test.go
@@ -5,7 +5,7 @@ import (
 	"net/http/httptest"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestNormalizeQueryValuesHandler(t *testing.T) {
--- a/api/server/structs/BUILD.bazel
+++ b/api/server/structs/BUILD.bazel
@@ -1,50 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "go_default_library",
-    srcs = [
-        "block.go",
-        "conversions.go",
-        "conversions_block.go",
-        "conversions_state.go",
-        "endpoints_beacon.go",
-        "endpoints_blob.go",
-        "endpoints_builder.go",
-        "endpoints_config.go",
-        "endpoints_debug.go",
-        "endpoints_events.go",
-        "endpoints_lightclient.go",
-        "endpoints_node.go",
-        "endpoints_rewards.go",
-        "endpoints_validator.go",
-        "other.go",
-        "state.go",
-    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/server/structs",
-    visibility = ["//visibility:public"],
-    deps = [
-        "//api/server:go_default_library",
-        "//beacon-chain/state:go_default_library",
-        "//config/fieldparams:go_default_library",
-        "//consensus-types/primitives:go_default_library",
-        "//consensus-types/validator:go_default_library",
-        "//container/slice:go_default_library",
-        "//encoding/bytesutil:go_default_library",
-        "//math:go_default_library",
-        "//proto/engine/v1:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-        "@com_github_ethereum_go_ethereum//common:go_default_library",
-        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
-    ],
-)
-
-go_test(
-    name = "go_default_test",
-    srcs = ["conversions_test.go"],
-    embed = [":go_default_library"],
-    deps = [
-        "//proto/prysm/v1alpha1:go_default_library",
-        "//testing/require:go_default_library",
-    ],
-)
--- a/api/server/structs/block.go
+++ b/api/server/structs/block.go
@@ -1,353 +0,0 @@
-package structs
-
-type SignedBeaconBlock struct {
-	Message   *BeaconBlock `json:"message"`
-	Signature string       `json:"signature"`
-}
-
-type BeaconBlock struct {
-	Slot          string           `json:"slot"`
-	ProposerIndex string           `json:"proposer_index"`
-	ParentRoot    string           `json:"parent_root"`
-	StateRoot     string           `json:"state_root"`
-	Body          *BeaconBlockBody `json:"body"`
-}
-
-type BeaconBlockBody struct {
-	RandaoReveal      string                 `json:"randao_reveal"`
-	Eth1Data          *Eth1Data              `json:"eth1_data"`
-	Graffiti          string                 `json:"graffiti"`
-	ProposerSlashings []*ProposerSlashing    `json:"proposer_slashings"`
-	AttesterSlashings []*AttesterSlashing    `json:"attester_slashings"`
-	Attestations      []*Attestation         `json:"attestations"`
-	Deposits          []*Deposit             `json:"deposits"`
-	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
-}
-
-type SignedBeaconBlockAltair struct {
-	Message   *BeaconBlockAltair `json:"message"`
-	Signature string             `json:"signature"`
-}
-
-type BeaconBlockAltair struct {
-	Slot          string                 `json:"slot"`
-	ProposerIndex string                 `json:"proposer_index"`
-	ParentRoot    string                 `json:"parent_root"`
-	StateRoot     string                 `json:"state_root"`
-	Body          *BeaconBlockBodyAltair `json:"body"`
-}
-
-type BeaconBlockBodyAltair struct {
-	RandaoReveal      string                 `json:"randao_reveal"`
-	Eth1Data          *Eth1Data              `json:"eth1_data"`
-	Graffiti          string                 `json:"graffiti"`
-	ProposerSlashings []*ProposerSlashing    `json:"proposer_slashings"`
-	AttesterSlashings []*AttesterSlashing    `json:"attester_slashings"`
-	Attestations      []*Attestation         `json:"attestations"`
-	Deposits          []*Deposit             `json:"deposits"`
-	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
-	SyncAggregate     *SyncAggregate         `json:"sync_aggregate"`
-}
-
-type SignedBeaconBlockBellatrix struct {
-	Message   *BeaconBlockBellatrix `json:"message"`
-	Signature string                `json:"signature"`
-}
-
-type BeaconBlockBellatrix struct {
-	Slot          string                    `json:"slot"`
-	ProposerIndex string                    `json:"proposer_index"`
-	ParentRoot    string                    `json:"parent_root"`
-	StateRoot     string                    `json:"state_root"`
-	Body          *BeaconBlockBodyBellatrix `json:"body"`
-}
-
-type BeaconBlockBodyBellatrix struct {
-	RandaoReveal      string                 `json:"randao_reveal"`
-	Eth1Data          *Eth1Data              `json:"eth1_data"`
-	Graffiti          string                 `json:"graffiti"`
-	ProposerSlashings []*ProposerSlashing    `json:"proposer_slashings"`
-	AttesterSlashings []*AttesterSlashing    `json:"attester_slashings"`
-	Attestations      []*Attestation         `json:"attestations"`
-	Deposits          []*Deposit             `json:"deposits"`
-	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
-	SyncAggregate     *SyncAggregate         `json:"sync_aggregate"`
-	ExecutionPayload  *ExecutionPayload      `json:"execution_payload"`
-}
-
-type SignedBlindedBeaconBlockBellatrix struct {
-	Message   *BlindedBeaconBlockBellatrix `json:"message"`
-	Signature string                       `json:"signature"`
-}
-
-type BlindedBeaconBlockBellatrix struct {
-	Slot          string                           `json:"slot"`
-	ProposerIndex string                           `json:"proposer_index"`
-	ParentRoot    string                           `json:"parent_root"`
-	StateRoot     string                           `json:"state_root"`
-	Body          *BlindedBeaconBlockBodyBellatrix `json:"body"`
-}
-
-type BlindedBeaconBlockBodyBellatrix struct {
-	RandaoReveal           string                  `json:"randao_reveal"`
-	Eth1Data               *Eth1Data               `json:"eth1_data"`
-	Graffiti               string                  `json:"graffiti"`
-	ProposerSlashings      []*ProposerSlashing     `json:"proposer_slashings"`
-	AttesterSlashings      []*AttesterSlashing     `json:"attester_slashings"`
-	Attestations           []*Attestation          `json:"attestations"`
-	Deposits               []*Deposit              `json:"deposits"`
-	VoluntaryExits         []*SignedVoluntaryExit  `json:"voluntary_exits"`
-	SyncAggregate          *SyncAggregate          `json:"sync_aggregate"`
-	ExecutionPayloadHeader *ExecutionPayloadHeader `json:"execution_payload_header"`
-}
-
-type SignedBeaconBlockCapella struct {
-	Message   *BeaconBlockCapella `json:"message"`
-	Signature string              `json:"signature"`
-}
-
-type BeaconBlockCapella struct {
-	Slot          string                  `json:"slot"`
-	ProposerIndex string                  `json:"proposer_index"`
-	ParentRoot    string                  `json:"parent_root"`
-	StateRoot     string                  `json:"state_root"`
-	Body          *BeaconBlockBodyCapella `json:"body"`
-}
-
-type BeaconBlockBodyCapella struct {
-	RandaoReveal          string                        `json:"randao_reveal"`
-	Eth1Data              *Eth1Data                     `json:"eth1_data"`
-	Graffiti              string                        `json:"graffiti"`
-	ProposerSlashings     []*ProposerSlashing           `json:"proposer_slashings"`
-	AttesterSlashings     []*AttesterSlashing           `json:"attester_slashings"`
-	Attestations          []*Attestation                `json:"attestations"`
-	Deposits              []*Deposit                    `json:"deposits"`
-	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
-	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
-	ExecutionPayload      *ExecutionPayloadCapella      `json:"execution_payload"`
-	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
-}
-
-type SignedBlindedBeaconBlockCapella struct {
-	Message   *BlindedBeaconBlockCapella `json:"message"`
-	Signature string                     `json:"signature"`
-}
-
-type BlindedBeaconBlockCapella struct {
-	Slot          string                         `json:"slot"`
-	ProposerIndex string                         `json:"proposer_index"`
-	ParentRoot    string                         `json:"parent_root"`
-	StateRoot     string                         `json:"state_root"`
-	Body          *BlindedBeaconBlockBodyCapella `json:"body"`
-}
-
-type BlindedBeaconBlockBodyCapella struct {
-	RandaoReveal           string                         `json:"randao_reveal"`
-	Eth1Data               *Eth1Data                      `json:"eth1_data"`
-	Graffiti               string                         `json:"graffiti"`
-	ProposerSlashings      []*ProposerSlashing            `json:"proposer_slashings"`
-	AttesterSlashings      []*AttesterSlashing            `json:"attester_slashings"`
-	Attestations           []*Attestation                 `json:"attestations"`
-	Deposits               []*Deposit                     `json:"deposits"`
-	VoluntaryExits         []*SignedVoluntaryExit         `json:"voluntary_exits"`
-	SyncAggregate          *SyncAggregate                 `json:"sync_aggregate"`
-	ExecutionPayloadHeader *ExecutionPayloadHeaderCapella `json:"execution_payload_header"`
-	BLSToExecutionChanges  []*SignedBLSToExecutionChange  `json:"bls_to_execution_changes"`
-}
-
-type SignedBeaconBlockContentsDeneb struct {
-	SignedBlock *SignedBeaconBlockDeneb `json:"signed_block"`
-	KzgProofs   []string                `json:"kzg_proofs"`
-	Blobs       []string                `json:"blobs"`
-}
-
-type BeaconBlockContentsDeneb struct {
-	Block     *BeaconBlockDeneb `json:"block"`
-	KzgProofs []string          `json:"kzg_proofs"`
-	Blobs     []string          `json:"blobs"`
-}
-
-type SignedBeaconBlockDeneb struct {
-	Message   *BeaconBlockDeneb `json:"message"`
-	Signature string            `json:"signature"`
-}
-
-type BeaconBlockDeneb struct {
-	Slot          string                `json:"slot"`
-	ProposerIndex string                `json:"proposer_index"`
-	ParentRoot    string                `json:"parent_root"`
-	StateRoot     string                `json:"state_root"`
-	Body          *BeaconBlockBodyDeneb `json:"body"`
-}
-
-type BeaconBlockBodyDeneb struct {
-	RandaoReveal          string                        `json:"randao_reveal"`
-	Eth1Data              *Eth1Data                     `json:"eth1_data"`
-	Graffiti              string                        `json:"graffiti"`
-	ProposerSlashings     []*ProposerSlashing           `json:"proposer_slashings"`
-	AttesterSlashings     []*AttesterSlashing           `json:"attester_slashings"`
-	Attestations          []*Attestation                `json:"attestations"`
-	Deposits              []*Deposit                    `json:"deposits"`
-	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
-	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
-	ExecutionPayload      *ExecutionPayloadDeneb        `json:"execution_payload"`
-	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
-	BlobKzgCommitments    []string                      `json:"blob_kzg_commitments"`
-}
-
-type BlindedBeaconBlockDeneb struct {
-	Slot          string                       `json:"slot"`
-	ProposerIndex string                       `json:"proposer_index"`
-	ParentRoot    string                       `json:"parent_root"`
-	StateRoot     string                       `json:"state_root"`
-	Body          *BlindedBeaconBlockBodyDeneb `json:"body"`
-}
-
-type SignedBlindedBeaconBlockDeneb struct {
-	Message   *BlindedBeaconBlockDeneb `json:"message"`
-	Signature string                   `json:"signature"`
-}
-
-type BlindedBeaconBlockBodyDeneb struct {
-	RandaoReveal           string                        `json:"randao_reveal"`
-	Eth1Data               *Eth1Data                     `json:"eth1_data"`
-	Graffiti               string                        `json:"graffiti"`
-	ProposerSlashings      []*ProposerSlashing           `json:"proposer_slashings"`
-	AttesterSlashings      []*AttesterSlashing           `json:"attester_slashings"`
-	Attestations           []*Attestation                `json:"attestations"`
-	Deposits               []*Deposit                    `json:"deposits"`
-	VoluntaryExits         []*SignedVoluntaryExit        `json:"voluntary_exits"`
-	SyncAggregate          *SyncAggregate                `json:"sync_aggregate"`
-	ExecutionPayloadHeader *ExecutionPayloadHeaderDeneb  `json:"execution_payload_header"`
-	BLSToExecutionChanges  []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
-	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
-}
-
-type SignedBeaconBlockHeaderContainer struct {
-	Header    *SignedBeaconBlockHeader `json:"header"`
-	Root      string                   `json:"root"`
-	Canonical bool                     `json:"canonical"`
-}
-
-type SignedBeaconBlockHeader struct {
-	Message   *BeaconBlockHeader `json:"message"`
-	Signature string             `json:"signature"`
-}
-
-type BeaconBlockHeader struct {
-	Slot          string `json:"slot"`
-	ProposerIndex string `json:"proposer_index"`
-	ParentRoot    string `json:"parent_root"`
-	StateRoot     string `json:"state_root"`
-	BodyRoot      string `json:"body_root"`
-}
-
-type ExecutionPayload struct {
-	ParentHash    string   `json:"parent_hash"`
-	FeeRecipient  string   `json:"fee_recipient"`
-	StateRoot     string   `json:"state_root"`
-	ReceiptsRoot  string   `json:"receipts_root"`
-	LogsBloom     string   `json:"logs_bloom"`
-	PrevRandao    string   `json:"prev_randao"`
-	BlockNumber   string   `json:"block_number"`
-	GasLimit      string   `json:"gas_limit"`
-	GasUsed       string   `json:"gas_used"`
-	Timestamp     string   `json:"timestamp"`
-	ExtraData     string   `json:"extra_data"`
-	BaseFeePerGas string   `json:"base_fee_per_gas"`
-	BlockHash     string   `json:"block_hash"`
-	Transactions  []string `json:"transactions"`
-}
-
-type ExecutionPayloadHeader struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-}
-
-type ExecutionPayloadCapella struct {
-	ParentHash    string        `json:"parent_hash"`
-	FeeRecipient  string        `json:"fee_recipient"`
-	StateRoot     string        `json:"state_root"`
-	ReceiptsRoot  string        `json:"receipts_root"`
-	LogsBloom     string        `json:"logs_bloom"`
-	PrevRandao    string        `json:"prev_randao"`
-	BlockNumber   string        `json:"block_number"`
-	GasLimit      string        `json:"gas_limit"`
-	GasUsed       string        `json:"gas_used"`
-	Timestamp     string        `json:"timestamp"`
-	ExtraData     string        `json:"extra_data"`
-	BaseFeePerGas string        `json:"base_fee_per_gas"`
-	BlockHash     string        `json:"block_hash"`
-	Transactions  []string      `json:"transactions"`
-	Withdrawals   []*Withdrawal `json:"withdrawals"`
-}
-
-type ExecutionPayloadHeaderCapella struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-	WithdrawalsRoot  string `json:"withdrawals_root"`
-}
-
-type ExecutionPayloadDeneb struct {
-	ParentHash    string        `json:"parent_hash"`
-	FeeRecipient  string        `json:"fee_recipient"`
-	StateRoot     string        `json:"state_root"`
-	ReceiptsRoot  string        `json:"receipts_root"`
-	LogsBloom     string        `json:"logs_bloom"`
-	PrevRandao    string        `json:"prev_randao"`
-	BlockNumber   string        `json:"block_number"`
-	GasLimit      string        `json:"gas_limit"`
-	GasUsed       string        `json:"gas_used"`
-	Timestamp     string        `json:"timestamp"`
-	ExtraData     string        `json:"extra_data"`
-	BaseFeePerGas string        `json:"base_fee_per_gas"`
-	BlockHash     string        `json:"block_hash"`
-	Transactions  []string      `json:"transactions"`
-	Withdrawals   []*Withdrawal `json:"withdrawals"`
-	BlobGasUsed   string        `json:"blob_gas_used"`
-	ExcessBlobGas string        `json:"excess_blob_gas"`
-}
-
-type ExecutionPayloadHeaderDeneb struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-	WithdrawalsRoot  string `json:"withdrawals_root"`
-	BlobGasUsed      string `json:"blob_gas_used"`
-	ExcessBlobGas    string `json:"excess_blob_gas"`
-}
--- a/api/server/structs/conversions.go
+++ b/api/server/structs/conversions.go
--- a/api/server/structs/conversions_block.go
+++ b/api/server/structs/conversions_block.go
--- a/api/server/structs/conversions_state.go
+++ b/api/server/structs/conversions_state.go
@@ -1,595 +0,0 @@
-package structs
-
-import (
-	"errors"
-	"fmt"
-
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	beaconState "github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-)
-
-var errPayloadHeaderNotFound = errors.New("expected payload header not found")
-
-func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error) {
-	srcBr := st.BlockRoots()
-	br := make([]string, len(srcBr))
-	for i, r := range srcBr {
-		br[i] = hexutil.Encode(r)
-	}
-	srcSr := st.StateRoots()
-	sr := make([]string, len(srcSr))
-	for i, r := range srcSr {
-		sr[i] = hexutil.Encode(r)
-	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
-	hr := make([]string, len(srcHr))
-	for i, r := range srcHr {
-		hr[i] = hexutil.Encode(r)
-	}
-	srcVotes := st.Eth1DataVotes()
-	votes := make([]*Eth1Data, len(srcVotes))
-	for i, e := range srcVotes {
-		votes[i] = Eth1DataFromConsensus(e)
-	}
-	srcVals := st.Validators()
-	vals := make([]*Validator, len(srcVals))
-	for i, v := range srcVals {
-		vals[i] = ValidatorFromConsensus(v)
-	}
-	srcBals := st.Balances()
-	bals := make([]string, len(srcBals))
-	for i, b := range srcBals {
-		bals[i] = fmt.Sprintf("%d", b)
-	}
-	srcRm := st.RandaoMixes()
-	rm := make([]string, len(srcRm))
-	for i, m := range srcRm {
-		rm[i] = hexutil.Encode(m)
-	}
-	srcSlashings := st.Slashings()
-	slashings := make([]string, len(srcSlashings))
-	for i, s := range srcSlashings {
-		slashings[i] = fmt.Sprintf("%d", s)
-	}
-	srcPrevAtts, err := st.PreviousEpochAttestations()
-	if err != nil {
-		return nil, err
-	}
-	prevAtts := make([]*PendingAttestation, len(srcPrevAtts))
-	for i, a := range srcPrevAtts {
-		prevAtts[i] = PendingAttestationFromConsensus(a)
-	}
-	srcCurrAtts, err := st.CurrentEpochAttestations()
-	if err != nil {
-		return nil, err
-	}
-	currAtts := make([]*PendingAttestation, len(srcCurrAtts))
-	for i, a := range srcCurrAtts {
-		currAtts[i] = PendingAttestationFromConsensus(a)
-	}
-
-	return &BeaconState{
-		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime()),
-		GenesisValidatorsRoot:       hexutil.Encode(st.GenesisValidatorsRoot()),
-		Slot:                        fmt.Sprintf("%d", st.Slot()),
-		Fork:                        ForkFromConsensus(st.Fork()),
-		LatestBlockHeader:           BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
-		BlockRoots:                  br,
-		StateRoots:                  sr,
-		HistoricalRoots:             hr,
-		Eth1Data:                    Eth1DataFromConsensus(st.Eth1Data()),
-		Eth1DataVotes:               votes,
-		Eth1DepositIndex:            fmt.Sprintf("%d", st.Eth1DepositIndex()),
-		Validators:                  vals,
-		Balances:                    bals,
-		RandaoMixes:                 rm,
-		Slashings:                   slashings,
-		PreviousEpochAttestations:   prevAtts,
-		CurrentEpochAttestations:    currAtts,
-		JustificationBits:           hexutil.Encode(st.JustificationBits()),
-		PreviousJustifiedCheckpoint: CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
-		CurrentJustifiedCheckpoint:  CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
-		FinalizedCheckpoint:         CheckpointFromConsensus(st.FinalizedCheckpoint()),
-	}, nil
-}
-
-func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAltair, error) {
-	srcBr := st.BlockRoots()
-	br := make([]string, len(srcBr))
-	for i, r := range srcBr {
-		br[i] = hexutil.Encode(r)
-	}
-	srcSr := st.StateRoots()
-	sr := make([]string, len(srcSr))
-	for i, r := range srcSr {
-		sr[i] = hexutil.Encode(r)
-	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
-	hr := make([]string, len(srcHr))
-	for i, r := range srcHr {
-		hr[i] = hexutil.Encode(r)
-	}
-	srcVotes := st.Eth1DataVotes()
-	votes := make([]*Eth1Data, len(srcVotes))
-	for i, e := range srcVotes {
-		votes[i] = Eth1DataFromConsensus(e)
-	}
-	srcVals := st.Validators()
-	vals := make([]*Validator, len(srcVals))
-	for i, v := range srcVals {
-		vals[i] = ValidatorFromConsensus(v)
-	}
-	srcBals := st.Balances()
-	bals := make([]string, len(srcBals))
-	for i, b := range srcBals {
-		bals[i] = fmt.Sprintf("%d", b)
-	}
-	srcRm := st.RandaoMixes()
-	rm := make([]string, len(srcRm))
-	for i, m := range srcRm {
-		rm[i] = hexutil.Encode(m)
-	}
-	srcSlashings := st.Slashings()
-	slashings := make([]string, len(srcSlashings))
-	for i, s := range srcSlashings {
-		slashings[i] = fmt.Sprintf("%d", s)
-	}
-	srcPrevPart, err := st.PreviousEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	prevPart := make([]string, len(srcPrevPart))
-	for i, p := range srcPrevPart {
-		prevPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcCurrPart, err := st.CurrentEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	currPart := make([]string, len(srcCurrPart))
-	for i, p := range srcCurrPart {
-		currPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcIs, err := st.InactivityScores()
-	if err != nil {
-		return nil, err
-	}
-	is := make([]string, len(srcIs))
-	for i, s := range srcIs {
-		is[i] = fmt.Sprintf("%d", s)
-	}
-	currSc, err := st.CurrentSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	nextSc, err := st.NextSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-
-	return &BeaconStateAltair{
-		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime()),
-		GenesisValidatorsRoot:       hexutil.Encode(st.GenesisValidatorsRoot()),
-		Slot:                        fmt.Sprintf("%d", st.Slot()),
-		Fork:                        ForkFromConsensus(st.Fork()),
-		LatestBlockHeader:           BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
-		BlockRoots:                  br,
-		StateRoots:                  sr,
-		HistoricalRoots:             hr,
-		Eth1Data:                    Eth1DataFromConsensus(st.Eth1Data()),
-		Eth1DataVotes:               votes,
-		Eth1DepositIndex:            fmt.Sprintf("%d", st.Eth1DepositIndex()),
-		Validators:                  vals,
-		Balances:                    bals,
-		RandaoMixes:                 rm,
-		Slashings:                   slashings,
-		PreviousEpochParticipation:  prevPart,
-		CurrentEpochParticipation:   currPart,
-		JustificationBits:           hexutil.Encode(st.JustificationBits()),
-		PreviousJustifiedCheckpoint: CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
-		CurrentJustifiedCheckpoint:  CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
-		FinalizedCheckpoint:         CheckpointFromConsensus(st.FinalizedCheckpoint()),
-		InactivityScores:            is,
-		CurrentSyncCommittee:        SyncCommitteeFromConsensus(currSc),
-		NextSyncCommittee:           SyncCommitteeFromConsensus(nextSc),
-	}, nil
-}
-
-func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconStateBellatrix, error) {
-	srcBr := st.BlockRoots()
-	br := make([]string, len(srcBr))
-	for i, r := range srcBr {
-		br[i] = hexutil.Encode(r)
-	}
-	srcSr := st.StateRoots()
-	sr := make([]string, len(srcSr))
-	for i, r := range srcSr {
-		sr[i] = hexutil.Encode(r)
-	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
-	hr := make([]string, len(srcHr))
-	for i, r := range srcHr {
-		hr[i] = hexutil.Encode(r)
-	}
-	srcVotes := st.Eth1DataVotes()
-	votes := make([]*Eth1Data, len(srcVotes))
-	for i, e := range srcVotes {
-		votes[i] = Eth1DataFromConsensus(e)
-	}
-	srcVals := st.Validators()
-	vals := make([]*Validator, len(srcVals))
-	for i, v := range srcVals {
-		vals[i] = ValidatorFromConsensus(v)
-	}
-	srcBals := st.Balances()
-	bals := make([]string, len(srcBals))
-	for i, b := range srcBals {
-		bals[i] = fmt.Sprintf("%d", b)
-	}
-	srcRm := st.RandaoMixes()
-	rm := make([]string, len(srcRm))
-	for i, m := range srcRm {
-		rm[i] = hexutil.Encode(m)
-	}
-	srcSlashings := st.Slashings()
-	slashings := make([]string, len(srcSlashings))
-	for i, s := range srcSlashings {
-		slashings[i] = fmt.Sprintf("%d", s)
-	}
-	srcPrevPart, err := st.PreviousEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	prevPart := make([]string, len(srcPrevPart))
-	for i, p := range srcPrevPart {
-		prevPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcCurrPart, err := st.CurrentEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	currPart := make([]string, len(srcCurrPart))
-	for i, p := range srcCurrPart {
-		currPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcIs, err := st.InactivityScores()
-	if err != nil {
-		return nil, err
-	}
-	is := make([]string, len(srcIs))
-	for i, s := range srcIs {
-		is[i] = fmt.Sprintf("%d", s)
-	}
-	currSc, err := st.CurrentSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	nextSc, err := st.NextSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	execData, err := st.LatestExecutionPayloadHeader()
-	if err != nil {
-		return nil, err
-	}
-	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeader)
-	if !ok {
-		return nil, errPayloadHeaderNotFound
-	}
-	payload, err := ExecutionPayloadHeaderFromConsensus(srcPayload)
-	if err != nil {
-		return nil, err
-	}
-
-	return &BeaconStateBellatrix{
-		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
-		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
-		Slot:                         fmt.Sprintf("%d", st.Slot()),
-		Fork:                         ForkFromConsensus(st.Fork()),
-		LatestBlockHeader:            BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
-		BlockRoots:                   br,
-		StateRoots:                   sr,
-		HistoricalRoots:              hr,
-		Eth1Data:                     Eth1DataFromConsensus(st.Eth1Data()),
-		Eth1DataVotes:                votes,
-		Eth1DepositIndex:             fmt.Sprintf("%d", st.Eth1DepositIndex()),
-		Validators:                   vals,
-		Balances:                     bals,
-		RandaoMixes:                  rm,
-		Slashings:                    slashings,
-		PreviousEpochParticipation:   prevPart,
-		CurrentEpochParticipation:    currPart,
-		JustificationBits:            hexutil.Encode(st.JustificationBits()),
-		PreviousJustifiedCheckpoint:  CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
-		CurrentJustifiedCheckpoint:   CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
-		FinalizedCheckpoint:          CheckpointFromConsensus(st.FinalizedCheckpoint()),
-		InactivityScores:             is,
-		CurrentSyncCommittee:         SyncCommitteeFromConsensus(currSc),
-		NextSyncCommittee:            SyncCommitteeFromConsensus(nextSc),
-		LatestExecutionPayloadHeader: payload,
-	}, nil
-}
-
-func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCapella, error) {
-	srcBr := st.BlockRoots()
-	br := make([]string, len(srcBr))
-	for i, r := range srcBr {
-		br[i] = hexutil.Encode(r)
-	}
-	srcSr := st.StateRoots()
-	sr := make([]string, len(srcSr))
-	for i, r := range srcSr {
-		sr[i] = hexutil.Encode(r)
-	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
-	hr := make([]string, len(srcHr))
-	for i, r := range srcHr {
-		hr[i] = hexutil.Encode(r)
-	}
-	srcVotes := st.Eth1DataVotes()
-	votes := make([]*Eth1Data, len(srcVotes))
-	for i, e := range srcVotes {
-		votes[i] = Eth1DataFromConsensus(e)
-	}
-	srcVals := st.Validators()
-	vals := make([]*Validator, len(srcVals))
-	for i, v := range srcVals {
-		vals[i] = ValidatorFromConsensus(v)
-	}
-	srcBals := st.Balances()
-	bals := make([]string, len(srcBals))
-	for i, b := range srcBals {
-		bals[i] = fmt.Sprintf("%d", b)
-	}
-	srcRm := st.RandaoMixes()
-	rm := make([]string, len(srcRm))
-	for i, m := range srcRm {
-		rm[i] = hexutil.Encode(m)
-	}
-	srcSlashings := st.Slashings()
-	slashings := make([]string, len(srcSlashings))
-	for i, s := range srcSlashings {
-		slashings[i] = fmt.Sprintf("%d", s)
-	}
-	srcPrevPart, err := st.PreviousEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	prevPart := make([]string, len(srcPrevPart))
-	for i, p := range srcPrevPart {
-		prevPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcCurrPart, err := st.CurrentEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	currPart := make([]string, len(srcCurrPart))
-	for i, p := range srcCurrPart {
-		currPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcIs, err := st.InactivityScores()
-	if err != nil {
-		return nil, err
-	}
-	is := make([]string, len(srcIs))
-	for i, s := range srcIs {
-		is[i] = fmt.Sprintf("%d", s)
-	}
-	currSc, err := st.CurrentSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	nextSc, err := st.NextSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	execData, err := st.LatestExecutionPayloadHeader()
-	if err != nil {
-		return nil, err
-	}
-	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeaderCapella)
-	if !ok {
-		return nil, errPayloadHeaderNotFound
-	}
-	payload, err := ExecutionPayloadHeaderCapellaFromConsensus(srcPayload)
-	if err != nil {
-		return nil, err
-	}
-	srcHs, err := st.HistoricalSummaries()
-	if err != nil {
-		return nil, err
-	}
-	hs := make([]*HistoricalSummary, len(srcHs))
-	for i, s := range srcHs {
-		hs[i] = HistoricalSummaryFromConsensus(s)
-	}
-	nwi, err := st.NextWithdrawalIndex()
-	if err != nil {
-		return nil, err
-	}
-	nwvi, err := st.NextWithdrawalValidatorIndex()
-	if err != nil {
-		return nil, err
-	}
-
-	return &BeaconStateCapella{
-		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
-		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
-		Slot:                         fmt.Sprintf("%d", st.Slot()),
-		Fork:                         ForkFromConsensus(st.Fork()),
-		LatestBlockHeader:            BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
-		BlockRoots:                   br,
-		StateRoots:                   sr,
-		HistoricalRoots:              hr,
-		Eth1Data:                     Eth1DataFromConsensus(st.Eth1Data()),
-		Eth1DataVotes:                votes,
-		Eth1DepositIndex:             fmt.Sprintf("%d", st.Eth1DepositIndex()),
-		Validators:                   vals,
-		Balances:                     bals,
-		RandaoMixes:                  rm,
-		Slashings:                    slashings,
-		PreviousEpochParticipation:   prevPart,
-		CurrentEpochParticipation:    currPart,
-		JustificationBits:            hexutil.Encode(st.JustificationBits()),
-		PreviousJustifiedCheckpoint:  CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
-		CurrentJustifiedCheckpoint:   CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
-		FinalizedCheckpoint:          CheckpointFromConsensus(st.FinalizedCheckpoint()),
-		InactivityScores:             is,
-		CurrentSyncCommittee:         SyncCommitteeFromConsensus(currSc),
-		NextSyncCommittee:            SyncCommitteeFromConsensus(nextSc),
-		LatestExecutionPayloadHeader: payload,
-		NextWithdrawalIndex:          fmt.Sprintf("%d", nwi),
-		NextWithdrawalValidatorIndex: fmt.Sprintf("%d", nwvi),
-		HistoricalSummaries:          hs,
-	}, nil
-}
-
-func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDeneb, error) {
-	srcBr := st.BlockRoots()
-	br := make([]string, len(srcBr))
-	for i, r := range srcBr {
-		br[i] = hexutil.Encode(r)
-	}
-	srcSr := st.StateRoots()
-	sr := make([]string, len(srcSr))
-	for i, r := range srcSr {
-		sr[i] = hexutil.Encode(r)
-	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
-	hr := make([]string, len(srcHr))
-	for i, r := range srcHr {
-		hr[i] = hexutil.Encode(r)
-	}
-	srcVotes := st.Eth1DataVotes()
-	votes := make([]*Eth1Data, len(srcVotes))
-	for i, e := range srcVotes {
-		votes[i] = Eth1DataFromConsensus(e)
-	}
-	srcVals := st.Validators()
-	vals := make([]*Validator, len(srcVals))
-	for i, v := range srcVals {
-		vals[i] = ValidatorFromConsensus(v)
-	}
-	srcBals := st.Balances()
-	bals := make([]string, len(srcBals))
-	for i, b := range srcBals {
-		bals[i] = fmt.Sprintf("%d", b)
-	}
-	srcRm := st.RandaoMixes()
-	rm := make([]string, len(srcRm))
-	for i, m := range srcRm {
-		rm[i] = hexutil.Encode(m)
-	}
-	srcSlashings := st.Slashings()
-	slashings := make([]string, len(srcSlashings))
-	for i, s := range srcSlashings {
-		slashings[i] = fmt.Sprintf("%d", s)
-	}
-	srcPrevPart, err := st.PreviousEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	prevPart := make([]string, len(srcPrevPart))
-	for i, p := range srcPrevPart {
-		prevPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcCurrPart, err := st.CurrentEpochParticipation()
-	if err != nil {
-		return nil, err
-	}
-	currPart := make([]string, len(srcCurrPart))
-	for i, p := range srcCurrPart {
-		currPart[i] = fmt.Sprintf("%d", p)
-	}
-	srcIs, err := st.InactivityScores()
-	if err != nil {
-		return nil, err
-	}
-	is := make([]string, len(srcIs))
-	for i, s := range srcIs {
-		is[i] = fmt.Sprintf("%d", s)
-	}
-	currSc, err := st.CurrentSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	nextSc, err := st.NextSyncCommittee()
-	if err != nil {
-		return nil, err
-	}
-	execData, err := st.LatestExecutionPayloadHeader()
-	if err != nil {
-		return nil, err
-	}
-	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
-	if !ok {
-		return nil, errPayloadHeaderNotFound
-	}
-	payload, err := ExecutionPayloadHeaderDenebFromConsensus(srcPayload)
-	if err != nil {
-		return nil, err
-	}
-	srcHs, err := st.HistoricalSummaries()
-	if err != nil {
-		return nil, err
-	}
-	hs := make([]*HistoricalSummary, len(srcHs))
-	for i, s := range srcHs {
-		hs[i] = HistoricalSummaryFromConsensus(s)
-	}
-	nwi, err := st.NextWithdrawalIndex()
-	if err != nil {
-		return nil, err
-	}
-	nwvi, err := st.NextWithdrawalValidatorIndex()
-	if err != nil {
-		return nil, err
-	}
-
-	return &BeaconStateDeneb{
-		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
-		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
-		Slot:                         fmt.Sprintf("%d", st.Slot()),
-		Fork:                         ForkFromConsensus(st.Fork()),
-		LatestBlockHeader:            BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
-		BlockRoots:                   br,
-		StateRoots:                   sr,
-		HistoricalRoots:              hr,
-		Eth1Data:                     Eth1DataFromConsensus(st.Eth1Data()),
-		Eth1DataVotes:                votes,
-		Eth1DepositIndex:             fmt.Sprintf("%d", st.Eth1DepositIndex()),
-		Validators:                   vals,
-		Balances:                     bals,
-		RandaoMixes:                  rm,
-		Slashings:                    slashings,
-		PreviousEpochParticipation:   prevPart,
-		CurrentEpochParticipation:    currPart,
-		JustificationBits:            hexutil.Encode(st.JustificationBits()),
-		PreviousJustifiedCheckpoint:  CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
-		CurrentJustifiedCheckpoint:   CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
-		FinalizedCheckpoint:          CheckpointFromConsensus(st.FinalizedCheckpoint()),
-		InactivityScores:             is,
-		CurrentSyncCommittee:         SyncCommitteeFromConsensus(currSc),
-		NextSyncCommittee:            SyncCommitteeFromConsensus(nextSc),
-		LatestExecutionPayloadHeader: payload,
-		NextWithdrawalIndex:          fmt.Sprintf("%d", nwi),
-		NextWithdrawalValidatorIndex: fmt.Sprintf("%d", nwvi),
-		HistoricalSummaries:          hs,
-	}, nil
-}
--- a/api/server/structs/conversions_test.go
+++ b/api/server/structs/conversions_test.go
@@ -1,26 +0,0 @@
-package structs
-
-import (
-	"testing"
-
-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-)
-
-func TestDepositSnapshotFromConsensus(t *testing.T) {
-	ds := &eth.DepositSnapshot{
-		Finalized:      [][]byte{{0xde, 0xad, 0xbe, 0xef}, {0xca, 0xfe, 0xba, 0xbe}},
-		DepositRoot:    []byte{0xab, 0xcd},
-		DepositCount:   12345,
-		ExecutionHash:  []byte{0x12, 0x34},
-		ExecutionDepth: 67890,
-	}
-
-	res := DepositSnapshotFromConsensus(ds)
-	require.NotNil(t, res)
-	require.DeepEqual(t, []string{"0xdeadbeef", "0xcafebabe"}, res.Finalized)
-	require.Equal(t, "0xabcd", res.DepositRoot)
-	require.Equal(t, "12345", res.DepositCount)
-	require.Equal(t, "0x1234", res.ExecutionBlockHash)
-	require.Equal(t, "67890", res.ExecutionBlockHeight)
-}
--- a/api/server/structs/endpoints_blob.go
+++ b/api/server/structs/endpoints_blob.go
@@ -1,14 +0,0 @@
-package structs
-
-type SidecarsResponse struct {
-	Data []*Sidecar `json:"data"`
-}
-
-type Sidecar struct {
-	Index                    string                   `json:"index"`
-	Blob                     string                   `json:"blob"`
-	SignedBeaconBlockHeader  *SignedBeaconBlockHeader `json:"signed_block_header"`
-	KzgCommitment            string                   `json:"kzg_commitment"`
-	KzgProof                 string                   `json:"kzg_proof"`
-	CommitmentInclusionProof []string                 `json:"kzg_commitment_inclusion_proof"`
-}
--- a/api/server/structs/endpoints_config.go
+++ b/api/server/structs/endpoints_config.go
@@ -1,18 +0,0 @@
-package structs
-
-type GetDepositContractResponse struct {
-	Data *DepositContractData `json:"data"`
-}
-
-type DepositContractData struct {
-	ChainId string `json:"chain_id"`
-	Address string `json:"address"`
-}
-
-type GetForkScheduleResponse struct {
-	Data []*Fork `json:"data"`
-}
-
-type GetSpecResponse struct {
-	Data interface{} `json:"data"`
-}
--- a/api/server/structs/endpoints_debug.go
+++ b/api/server/structs/endpoints_debug.go
@@ -1,57 +0,0 @@
-package structs
-
-import (
-	"encoding/json"
-)
-
-type GetBeaconStateV2Response struct {
-	Version             string          `json:"version"`
-	ExecutionOptimistic bool            `json:"execution_optimistic"`
-	Finalized           bool            `json:"finalized"`
-	Data                json.RawMessage `json:"data"` // represents the state values based on the version
-}
-
-type GetForkChoiceHeadsV2Response struct {
-	Data []*ForkChoiceHead `json:"data"`
-}
-
-type ForkChoiceHead struct {
-	Root                string `json:"root"`
-	Slot                string `json:"slot"`
-	ExecutionOptimistic bool   `json:"execution_optimistic"`
-}
-
-type GetForkChoiceDumpResponse struct {
-	JustifiedCheckpoint *Checkpoint              `json:"justified_checkpoint"`
-	FinalizedCheckpoint *Checkpoint              `json:"finalized_checkpoint"`
-	ForkChoiceNodes     []*ForkChoiceNode        `json:"fork_choice_nodes"`
-	ExtraData           *ForkChoiceDumpExtraData `json:"extra_data"`
-}
-
-type ForkChoiceDumpExtraData struct {
-	UnrealizedJustifiedCheckpoint *Checkpoint `json:"unrealized_justified_checkpoint"`
-	UnrealizedFinalizedCheckpoint *Checkpoint `json:"unrealized_finalized_checkpoint"`
-	ProposerBoostRoot             string      `json:"proposer_boost_root"`
-	PreviousProposerBoostRoot     string      `json:"previous_proposer_boost_root"`
-	HeadRoot                      string      `json:"head_root"`
-}
-
-type ForkChoiceNode struct {
-	Slot               string                   `json:"slot"`
-	BlockRoot          string                   `json:"block_root"`
-	ParentRoot         string                   `json:"parent_root"`
-	JustifiedEpoch     string                   `json:"justified_epoch"`
-	FinalizedEpoch     string                   `json:"finalized_epoch"`
-	Weight             string                   `json:"weight"`
-	Validity           string                   `json:"validity"`
-	ExecutionBlockHash string                   `json:"execution_block_hash"`
-	ExtraData          *ForkChoiceNodeExtraData `json:"extra_data"`
-}
-
-type ForkChoiceNodeExtraData struct {
-	UnrealizedJustifiedEpoch string `json:"unrealized_justified_epoch"`
-	UnrealizedFinalizedEpoch string `json:"unrealized_finalized_epoch"`
-	Balance                  string `json:"balance"`
-	ExecutionOptimistic      bool   `json:"execution_optimistic"`
-	TimeStamp                string `json:"timestamp"`
-}
--- a/api/server/structs/endpoints_events.go
+++ b/api/server/structs/endpoints_events.go
@@ -1,116 +0,0 @@
-package structs
-
-import (
-	"encoding/json"
-)
-
-type HeadEvent struct {
-	Slot                      string `json:"slot"`
-	Block                     string `json:"block"`
-	State                     string `json:"state"`
-	EpochTransition           bool   `json:"epoch_transition"`
-	ExecutionOptimistic       bool   `json:"execution_optimistic"`
-	PreviousDutyDependentRoot string `json:"previous_duty_dependent_root"`
-	CurrentDutyDependentRoot  string `json:"current_duty_dependent_root"`
-}
-
-type BlockEvent struct {
-	Slot                string `json:"slot"`
-	Block               string `json:"block"`
-	ExecutionOptimistic bool   `json:"execution_optimistic"`
-}
-
-type AggregatedAttEventSource struct {
-	Aggregate *Attestation `json:"aggregate"`
-}
-
-type UnaggregatedAttEventSource struct {
-	AggregationBits string           `json:"aggregation_bits"`
-	Data            *AttestationData `json:"data"`
-	Signature       string           `json:"signature"`
-}
-
-type FinalizedCheckpointEvent struct {
-	Block               string `json:"block"`
-	State               string `json:"state"`
-	Epoch               string `json:"epoch"`
-	ExecutionOptimistic bool   `json:"execution_optimistic"`
-}
-
-type ChainReorgEvent struct {
-	Slot                string `json:"slot"`
-	Depth               string `json:"depth"`
-	OldHeadBlock        string `json:"old_head_block"`
-	NewHeadBlock        string `json:"old_head_state"`
-	OldHeadState        string `json:"new_head_block"`
-	NewHeadState        string `json:"new_head_state"`
-	Epoch               string `json:"epoch"`
-	ExecutionOptimistic bool   `json:"execution_optimistic"`
-}
-
-type PayloadAttributesEvent struct {
-	Version string          `json:"version"`
-	Data    json.RawMessage `json:"data"`
-}
-
-type PayloadAttributesEventData struct {
-	ProposerIndex     string          `json:"proposer_index"`
-	ProposalSlot      string          `json:"proposal_slot"`
-	ParentBlockNumber string          `json:"parent_block_number"`
-	ParentBlockRoot   string          `json:"parent_block_root"`
-	ParentBlockHash   string          `json:"parent_block_hash"`
-	PayloadAttributes json.RawMessage `json:"payload_attributes"`
-}
-
-type PayloadAttributesV1 struct {
-	Timestamp             string `json:"timestamp"`
-	PrevRandao            string `json:"prev_randao"`
-	SuggestedFeeRecipient string `json:"suggested_fee_recipient"`
-}
-
-type PayloadAttributesV2 struct {
-	Timestamp             string        `json:"timestamp"`
-	PrevRandao            string        `json:"prev_randao"`
-	SuggestedFeeRecipient string        `json:"suggested_fee_recipient"`
-	Withdrawals           []*Withdrawal `json:"withdrawals"`
-}
-
-type PayloadAttributesV3 struct {
-	Timestamp             string        `json:"timestamp"`
-	PrevRandao            string        `json:"prev_randao"`
-	SuggestedFeeRecipient string        `json:"suggested_fee_recipient"`
-	Withdrawals           []*Withdrawal `json:"withdrawals"`
-	ParentBeaconBlockRoot string        `json:"parent_beacon_block_root"`
-}
-
-type BlobSidecarEvent struct {
-	BlockRoot     string `json:"block_root"`
-	Index         string `json:"index"`
-	Slot          string `json:"slot"`
-	KzgCommitment string `json:"kzg_commitment"`
-	VersionedHash string `json:"versioned_hash"`
-}
-
-type LightClientFinalityUpdateEvent struct {
-	Version string                     `json:"version"`
-	Data    *LightClientFinalityUpdate `json:"data"`
-}
-
-type LightClientFinalityUpdate struct {
-	AttestedHeader  *BeaconBlockHeader `json:"attested_header"`
-	FinalizedHeader *BeaconBlockHeader `json:"finalized_header"`
-	FinalityBranch  []string           `json:"finality_branch"`
-	SyncAggregate   *SyncAggregate     `json:"sync_aggregate"`
-	SignatureSlot   string             `json:"signature_slot"`
-}
-
-type LightClientOptimisticUpdateEvent struct {
-	Version string                       `json:"version"`
-	Data    *LightClientOptimisticUpdate `json:"data"`
-}
-
-type LightClientOptimisticUpdate struct {
-	AttestedHeader *BeaconBlockHeader `json:"attested_header"`
-	SyncAggregate  *SyncAggregate     `json:"sync_aggregate"`
-	SignatureSlot  string             `json:"signature_slot"`
-}
--- a/api/server/structs/endpoints_lightclient.go
+++ b/api/server/structs/endpoints_lightclient.go
@@ -1,31 +0,0 @@
-package structs
-
-type LightClientBootstrapResponse struct {
-	Version string                `json:"version"`
-	Data    *LightClientBootstrap `json:"data"`
-}
-
-type LightClientBootstrap struct {
-	Header                     *BeaconBlockHeader `json:"header"`
-	CurrentSyncCommittee       *SyncCommittee     `json:"current_sync_committee"`
-	CurrentSyncCommitteeBranch []string           `json:"current_sync_committee_branch"`
-}
-
-type LightClientUpdate struct {
-	AttestedHeader          *BeaconBlockHeader `json:"attested_header"`
-	NextSyncCommittee       *SyncCommittee     `json:"next_sync_committee,omitempty"`
-	FinalizedHeader         *BeaconBlockHeader `json:"finalized_header,omitempty"`
-	SyncAggregate           *SyncAggregate     `json:"sync_aggregate"`
-	NextSyncCommitteeBranch []string           `json:"next_sync_committee_branch,omitempty"`
-	FinalityBranch          []string           `json:"finality_branch,omitempty"`
-	SignatureSlot           string             `json:"signature_slot"`
-}
-
-type LightClientUpdateWithVersion struct {
-	Version string             `json:"version"`
-	Data    *LightClientUpdate `json:"data"`
-}
-
-type LightClientUpdatesByRangeResponse struct {
-	Updates []*LightClientUpdateWithVersion `json:"updates"`
-}
--- a/api/server/structs/other.go
+++ b/api/server/structs/other.go
@@ -1,209 +0,0 @@
-package structs
-
-type Validator struct {
-	Pubkey                     string `json:"pubkey"`
-	WithdrawalCredentials      string `json:"withdrawal_credentials"`
-	EffectiveBalance           string `json:"effective_balance"`
-	Slashed                    bool   `json:"slashed"`
-	ActivationEligibilityEpoch string `json:"activation_eligibility_epoch"`
-	ActivationEpoch            string `json:"activation_epoch"`
-	ExitEpoch                  string `json:"exit_epoch"`
-	WithdrawableEpoch          string `json:"withdrawable_epoch"`
-}
-
-type PendingAttestation struct {
-	AggregationBits string           `json:"aggregation_bits"`
-	Data            *AttestationData `json:"data"`
-	InclusionDelay  string           `json:"inclusion_delay"`
-	ProposerIndex   string           `json:"proposer_index"`
-}
-
-type HistoricalSummary struct {
-	BlockSummaryRoot string `json:"block_summary_root"`
-	StateSummaryRoot string `json:"state_summary_root"`
-}
-
-type Attestation struct {
-	AggregationBits string           `json:"aggregation_bits"`
-	Data            *AttestationData `json:"data"`
-	Signature       string           `json:"signature"`
-}
-
-type AttestationData struct {
-	Slot            string      `json:"slot"`
-	CommitteeIndex  string      `json:"index"`
-	BeaconBlockRoot string      `json:"beacon_block_root"`
-	Source          *Checkpoint `json:"source"`
-	Target          *Checkpoint `json:"target"`
-}
-
-type Checkpoint struct {
-	Epoch string `json:"epoch"`
-	Root  string `json:"root"`
-}
-
-type Committee struct {
-	Index      string   `json:"index"`
-	Slot       string   `json:"slot"`
-	Validators []string `json:"validators"`
-}
-
-type SignedContributionAndProof struct {
-	Message   *ContributionAndProof `json:"message"`
-	Signature string                `json:"signature"`
-}
-
-type ContributionAndProof struct {
-	AggregatorIndex string                     `json:"aggregator_index"`
-	Contribution    *SyncCommitteeContribution `json:"contribution"`
-	SelectionProof  string                     `json:"selection_proof"`
-}
-
-type SyncCommitteeContribution struct {
-	Slot              string `json:"slot"`
-	BeaconBlockRoot   string `json:"beacon_block_root"`
-	SubcommitteeIndex string `json:"subcommittee_index"`
-	AggregationBits   string `json:"aggregation_bits"`
-	Signature         string `json:"signature"`
-}
-
-type SignedAggregateAttestationAndProof struct {
-	Message   *AggregateAttestationAndProof `json:"message"`
-	Signature string                        `json:"signature"`
-}
-
-type AggregateAttestationAndProof struct {
-	AggregatorIndex string       `json:"aggregator_index"`
-	Aggregate       *Attestation `json:"aggregate"`
-	SelectionProof  string       `json:"selection_proof"`
-}
-
-type SyncCommitteeSubscription struct {
-	ValidatorIndex       string   `json:"validator_index"`
-	SyncCommitteeIndices []string `json:"sync_committee_indices"`
-	UntilEpoch           string   `json:"until_epoch"`
-}
-
-type BeaconCommitteeSubscription struct {
-	ValidatorIndex   string `json:"validator_index"`
-	CommitteeIndex   string `json:"committee_index"`
-	CommitteesAtSlot string `json:"committees_at_slot"`
-	Slot             string `json:"slot"`
-	IsAggregator     bool   `json:"is_aggregator"`
-}
-
-type ValidatorRegistration struct {
-	FeeRecipient string `json:"fee_recipient"`
-	GasLimit     string `json:"gas_limit"`
-	Timestamp    string `json:"timestamp"`
-	Pubkey       string `json:"pubkey"`
-}
-
-type SignedValidatorRegistration struct {
-	Message   *ValidatorRegistration `json:"message"`
-	Signature string                 `json:"signature"`
-}
-
-type FeeRecipient struct {
-	ValidatorIndex string `json:"validator_index"`
-	FeeRecipient   string `json:"fee_recipient"`
-}
-
-type SignedVoluntaryExit struct {
-	Message   *VoluntaryExit `json:"message"`
-	Signature string         `json:"signature"`
-}
-
-type VoluntaryExit struct {
-	Epoch          string `json:"epoch"`
-	ValidatorIndex string `json:"validator_index"`
-}
-
-type Fork struct {
-	PreviousVersion string `json:"previous_version"`
-	CurrentVersion  string `json:"current_version"`
-	Epoch           string `json:"epoch"`
-}
-
-type SignedBLSToExecutionChange struct {
-	Message   *BLSToExecutionChange `json:"message"`
-	Signature string                `json:"signature"`
-}
-
-type BLSToExecutionChange struct {
-	ValidatorIndex     string `json:"validator_index"`
-	FromBLSPubkey      string `json:"from_bls_pubkey"`
-	ToExecutionAddress string `json:"to_execution_address"`
-}
-
-type SyncCommitteeMessage struct {
-	Slot            string `json:"slot"`
-	BeaconBlockRoot string `json:"beacon_block_root"`
-	ValidatorIndex  string `json:"validator_index"`
-	Signature       string `json:"signature"`
-}
-
-type SyncCommittee struct {
-	Pubkeys         []string `json:"pubkeys"`
-	AggregatePubkey string   `json:"aggregate_pubkey"`
-}
-
-// SyncDetails contains information about node sync status.
-type SyncDetails struct {
-	HeadSlot     string `json:"head_slot"`
-	SyncDistance string `json:"sync_distance"`
-	IsSyncing    bool   `json:"is_syncing"`
-	IsOptimistic bool   `json:"is_optimistic"`
-	ElOffline    bool   `json:"el_offline"`
-}
-
-// SyncDetailsContainer is a wrapper for Data.
-type SyncDetailsContainer struct {
-	Data *SyncDetails `json:"data"`
-}
-
-type Eth1Data struct {
-	DepositRoot  string `json:"deposit_root"`
-	DepositCount string `json:"deposit_count"`
-	BlockHash    string `json:"block_hash"`
-}
-
-type ProposerSlashing struct {
-	SignedHeader1 *SignedBeaconBlockHeader `json:"signed_header_1"`
-	SignedHeader2 *SignedBeaconBlockHeader `json:"signed_header_2"`
-}
-
-type AttesterSlashing struct {
-	Attestation1 *IndexedAttestation `json:"attestation_1"`
-	Attestation2 *IndexedAttestation `json:"attestation_2"`
-}
-
-type Deposit struct {
-	Proof []string     `json:"proof"`
-	Data  *DepositData `json:"data"`
-}
-
-type DepositData struct {
-	Pubkey                string `json:"pubkey"`
-	WithdrawalCredentials string `json:"withdrawal_credentials"`
-	Amount                string `json:"amount"`
-	Signature             string `json:"signature"`
-}
-
-type IndexedAttestation struct {
-	AttestingIndices []string         `json:"attesting_indices"`
-	Data             *AttestationData `json:"data"`
-	Signature        string           `json:"signature"`
-}
-
-type SyncAggregate struct {
-	SyncCommitteeBits      string `json:"sync_committee_bits"`
-	SyncCommitteeSignature string `json:"sync_committee_signature"`
-}
-
-type Withdrawal struct {
-	WithdrawalIndex  string `json:"index"`
-	ValidatorIndex   string `json:"validator_index"`
-	ExecutionAddress string `json:"address"`
-	Amount           string `json:"amount"`
-}
--- a/api/server/structs/state.go
+++ b/api/server/structs/state.go
@@ -1,142 +0,0 @@
-package structs
-
-type BeaconState struct {
-	GenesisTime                 string                `json:"genesis_time"`
-	GenesisValidatorsRoot       string                `json:"genesis_validators_root"`
-	Slot                        string                `json:"slot"`
-	Fork                        *Fork                 `json:"fork"`
-	LatestBlockHeader           *BeaconBlockHeader    `json:"latest_block_header"`
-	BlockRoots                  []string              `json:"block_roots"`
-	StateRoots                  []string              `json:"state_roots"`
-	HistoricalRoots             []string              `json:"historical_roots"`
-	Eth1Data                    *Eth1Data             `json:"eth1_data"`
-	Eth1DataVotes               []*Eth1Data           `json:"eth1_data_votes"`
-	Eth1DepositIndex            string                `json:"eth1_deposit_index"`
-	Validators                  []*Validator          `json:"validators"`
-	Balances                    []string              `json:"balances"`
-	RandaoMixes                 []string              `json:"randao_mixes"`
-	Slashings                   []string              `json:"slashings"`
-	PreviousEpochAttestations   []*PendingAttestation `json:"previous_epoch_attestations"`
-	CurrentEpochAttestations    []*PendingAttestation `json:"current_epoch_attestations"`
-	JustificationBits           string                `json:"justification_bits"`
-	PreviousJustifiedCheckpoint *Checkpoint           `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint  *Checkpoint           `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint         *Checkpoint           `json:"finalized_checkpoint"`
-}
-
-type BeaconStateAltair struct {
-	GenesisTime                 string             `json:"genesis_time"`
-	GenesisValidatorsRoot       string             `json:"genesis_validators_root"`
-	Slot                        string             `json:"slot"`
-	Fork                        *Fork              `json:"fork"`
-	LatestBlockHeader           *BeaconBlockHeader `json:"latest_block_header"`
-	BlockRoots                  []string           `json:"block_roots"`
-	StateRoots                  []string           `json:"state_roots"`
-	HistoricalRoots             []string           `json:"historical_roots"`
-	Eth1Data                    *Eth1Data          `json:"eth1_data"`
-	Eth1DataVotes               []*Eth1Data        `json:"eth1_data_votes"`
-	Eth1DepositIndex            string             `json:"eth1_deposit_index"`
-	Validators                  []*Validator       `json:"validators"`
-	Balances                    []string           `json:"balances"`
-	RandaoMixes                 []string           `json:"randao_mixes"`
-	Slashings                   []string           `json:"slashings"`
-	PreviousEpochParticipation  []string           `json:"previous_epoch_participation"`
-	CurrentEpochParticipation   []string           `json:"current_epoch_participation"`
-	JustificationBits           string             `json:"justification_bits"`
-	PreviousJustifiedCheckpoint *Checkpoint        `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint  *Checkpoint        `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint         *Checkpoint        `json:"finalized_checkpoint"`
-	InactivityScores            []string           `json:"inactivity_scores"`
-	CurrentSyncCommittee        *SyncCommittee     `json:"current_sync_committee"`
-	NextSyncCommittee           *SyncCommittee     `json:"next_sync_committee"`
-}
-
-type BeaconStateBellatrix struct {
-	GenesisTime                  string                  `json:"genesis_time"`
-	GenesisValidatorsRoot        string                  `json:"genesis_validators_root"`
-	Slot                         string                  `json:"slot"`
-	Fork                         *Fork                   `json:"fork"`
-	LatestBlockHeader            *BeaconBlockHeader      `json:"latest_block_header"`
-	BlockRoots                   []string                `json:"block_roots"`
-	StateRoots                   []string                `json:"state_roots"`
-	HistoricalRoots              []string                `json:"historical_roots"`
-	Eth1Data                     *Eth1Data               `json:"eth1_data"`
-	Eth1DataVotes                []*Eth1Data             `json:"eth1_data_votes"`
-	Eth1DepositIndex             string                  `json:"eth1_deposit_index"`
-	Validators                   []*Validator            `json:"validators"`
-	Balances                     []string                `json:"balances"`
-	RandaoMixes                  []string                `json:"randao_mixes"`
-	Slashings                    []string                `json:"slashings"`
-	PreviousEpochParticipation   []string                `json:"previous_epoch_participation"`
-	CurrentEpochParticipation    []string                `json:"current_epoch_participation"`
-	JustificationBits            string                  `json:"justification_bits"`
-	PreviousJustifiedCheckpoint  *Checkpoint             `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint   *Checkpoint             `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint          *Checkpoint             `json:"finalized_checkpoint"`
-	InactivityScores             []string                `json:"inactivity_scores"`
-	CurrentSyncCommittee         *SyncCommittee          `json:"current_sync_committee"`
-	NextSyncCommittee            *SyncCommittee          `json:"next_sync_committee"`
-	LatestExecutionPayloadHeader *ExecutionPayloadHeader `json:"latest_execution_payload_header"`
-}
-
-type BeaconStateCapella struct {
-	GenesisTime                  string                         `json:"genesis_time"`
-	GenesisValidatorsRoot        string                         `json:"genesis_validators_root"`
-	Slot                         string                         `json:"slot"`
-	Fork                         *Fork                          `json:"fork"`
-	LatestBlockHeader            *BeaconBlockHeader             `json:"latest_block_header"`
-	BlockRoots                   []string                       `json:"block_roots"`
-	StateRoots                   []string                       `json:"state_roots"`
-	HistoricalRoots              []string                       `json:"historical_roots"`
-	Eth1Data                     *Eth1Data                      `json:"eth1_data"`
-	Eth1DataVotes                []*Eth1Data                    `json:"eth1_data_votes"`
-	Eth1DepositIndex             string                         `json:"eth1_deposit_index"`
-	Validators                   []*Validator                   `json:"validators"`
-	Balances                     []string                       `json:"balances"`
-	RandaoMixes                  []string                       `json:"randao_mixes"`
-	Slashings                    []string                       `json:"slashings"`
-	PreviousEpochParticipation   []string                       `json:"previous_epoch_participation"`
-	CurrentEpochParticipation    []string                       `json:"current_epoch_participation"`
-	JustificationBits            string                         `json:"justification_bits"`
-	PreviousJustifiedCheckpoint  *Checkpoint                    `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint   *Checkpoint                    `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint          *Checkpoint                    `json:"finalized_checkpoint"`
-	InactivityScores             []string                       `json:"inactivity_scores"`
-	CurrentSyncCommittee         *SyncCommittee                 `json:"current_sync_committee"`
-	NextSyncCommittee            *SyncCommittee                 `json:"next_sync_committee"`
-	LatestExecutionPayloadHeader *ExecutionPayloadHeaderCapella `json:"latest_execution_payload_header"`
-	NextWithdrawalIndex          string                         `json:"next_withdrawal_index"`
-	NextWithdrawalValidatorIndex string                         `json:"next_withdrawal_validator_index"`
-	HistoricalSummaries          []*HistoricalSummary           `json:"historical_summaries"`
-}
-
-type BeaconStateDeneb struct {
-	GenesisTime                  string                       `json:"genesis_time"`
-	GenesisValidatorsRoot        string                       `json:"genesis_validators_root"`
-	Slot                         string                       `json:"slot"`
-	Fork                         *Fork                        `json:"fork"`
-	LatestBlockHeader            *BeaconBlockHeader           `json:"latest_block_header"`
-	BlockRoots                   []string                     `json:"block_roots"`
-	StateRoots                   []string                     `json:"state_roots"`
-	HistoricalRoots              []string                     `json:"historical_roots"`
-	Eth1Data                     *Eth1Data                    `json:"eth1_data"`
-	Eth1DataVotes                []*Eth1Data                  `json:"eth1_data_votes"`
-	Eth1DepositIndex             string                       `json:"eth1_deposit_index"`
-	Validators                   []*Validator                 `json:"validators"`
-	Balances                     []string                     `json:"balances"`
-	RandaoMixes                  []string                     `json:"randao_mixes"`
-	Slashings                    []string                     `json:"slashings"`
-	PreviousEpochParticipation   []string                     `json:"previous_epoch_participation"`
-	CurrentEpochParticipation    []string                     `json:"current_epoch_participation"`
-	JustificationBits            string                       `json:"justification_bits"`
-	PreviousJustifiedCheckpoint  *Checkpoint                  `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint   *Checkpoint                  `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint          *Checkpoint                  `json:"finalized_checkpoint"`
-	InactivityScores             []string                     `json:"inactivity_scores"`
-	CurrentSyncCommittee         *SyncCommittee               `json:"current_sync_committee"`
-	NextSyncCommittee            *SyncCommittee               `json:"next_sync_committee"`
-	LatestExecutionPayloadHeader *ExecutionPayloadHeaderDeneb `json:"latest_execution_payload_header"`
-	NextWithdrawalIndex          string                       `json:"next_withdrawal_index"`
-	NextWithdrawalValidatorIndex string                       `json:"next_withdrawal_validator_index"`
-	HistoricalSummaries          []*HistoricalSummary         `json:"historical_summaries"`
-}
--- a/api/server/util_test.go
+++ b/api/server/util_test.go
@@ -3,8 +3,8 @@ package server
 import (
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestNormalizeQueryValues(t *testing.T) {
--- a/async/BUILD.bazel
+++ b/async/BUILD.bazel
@@ -8,7 +8,7 @@ go_library(
        "multilock.go",
        "scatter.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/async",
+    importpath = "github.com/prysmaticlabs/prysm/v4/async",
    visibility = ["//visibility:public"],
    deps = ["@com_github_sirupsen_logrus//:go_default_library"],
 )
--- a/async/abool/BUILD.bazel
+++ b/async/abool/BUILD.bazel
@@ -3,7 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = ["abool.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/async/abool",
+    importpath = "github.com/prysmaticlabs/prysm/v4/async/abool",
    visibility = ["//visibility:public"],
 )

--- a/async/benchmark_test.go
+++ b/async/benchmark_test.go
@@ -6,8 +6,8 @@ import (
 	"sync"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/async"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/async"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	log "github.com/sirupsen/logrus"
 )

--- a/async/debounce_test.go
+++ b/async/debounce_test.go
@@ -7,10 +7,10 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/async"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v4/async"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )

 func TestDebounce_NoEvents(t *testing.T) {
--- a/async/event/BUILD.bazel
+++ b/async/event/BUILD.bazel
@@ -6,7 +6,7 @@ go_library(
        "feed.go",
        "subscription.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/async/event",
+    importpath = "github.com/prysmaticlabs/prysm/v4/async/event",
    visibility = ["//visibility:public"],
    deps = ["//time/mclock:go_default_library"],
 )
--- a/async/event/example_feed_test.go
+++ b/async/event/example_feed_test.go
@@ -19,7 +19,7 @@ package event_test
 import (
 	"fmt"

-	"github.com/prysmaticlabs/prysm/v5/async/event"
+	"github.com/prysmaticlabs/prysm/v4/async/event"
 )

 func ExampleFeed_acknowledgedEvents() {
--- a/async/event/example_scope_test.go
+++ b/async/event/example_scope_test.go
@@ -20,7 +20,7 @@ import (
 	"fmt"
 	"sync"

-	"github.com/prysmaticlabs/prysm/v5/async/event"
+	"github.com/prysmaticlabs/prysm/v4/async/event"
 )

 // This example demonstrates how SubscriptionScope can be used to control the lifetime of
--- a/async/event/example_subscription_test.go
+++ b/async/event/example_subscription_test.go
@@ -19,7 +19,7 @@ package event_test
 import (
 	"fmt"

-	"github.com/prysmaticlabs/prysm/v5/async/event"
+	"github.com/prysmaticlabs/prysm/v4/async/event"
 )

 func ExampleNewSubscription() {
--- a/async/event/feed_test.go
+++ b/async/event/feed_test.go
@@ -23,7 +23,7 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
 )

 func TestFeedPanics(t *testing.T) {
--- a/async/event/subscription.go
+++ b/async/event/subscription.go
@@ -21,7 +21,7 @@ import (
 	"sync"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/time/mclock"
+	"github.com/prysmaticlabs/prysm/v4/time/mclock"
 )

 // waitQuotient is divided against the max backoff time, in order to have N requests based on the full
--- a/async/event/subscription_test.go
+++ b/async/event/subscription_test.go
@@ -23,7 +23,7 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 var errInts = errors.New("error in subscribeInts")
--- a/async/every_test.go
+++ b/async/every_test.go
@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/async"
+	"github.com/prysmaticlabs/prysm/v4/async"
 )

 func TestEveryRuns(t *testing.T) {
--- a/async/scatter_test.go
+++ b/async/scatter_test.go
@@ -5,9 +5,9 @@ import (
 	"sync"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/async"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/async"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestDouble(t *testing.T) {
--- a/beacon-chain/BUILD.bazel
+++ b/beacon-chain/BUILD.bazel
@@ -0,0 +1,19 @@
+load("//tools:target_migration.bzl", "moved_targets")
+
+moved_targets(
+    [
+        ":push_images_debug",
+        ":push_images_alpine",
+        ":push_images",
+        ":image_bundle_debug",
+        ":image_debug",
+        ":image_bundle_alpine",
+        ":image_bundle",
+        ":image_with_creation_time",
+        ":image_alpine",
+        ":image",
+        ":go_default_test",
+        ":beacon-chain",
+    ],
+    "//cmd/beacon-chain",
+)
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -6,7 +6,6 @@ go_library(
        "chain_info.go",
        "chain_info_forkchoice.go",
        "currently_syncing_block.go",
-        "defragment.go",
        "error.go",
        "execution_engine.go",
        "forkchoice_update_execution.go",
@@ -27,10 +26,9 @@ go_library(
        "receive_blob.go",
        "receive_block.go",
        "service.go",
-        "tracked_proposer.go",
        "weak_subjectivity_checks.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain",
+    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//cmd/beacon-chain:__subpackages__",
@@ -53,8 +51,8 @@ go_library(
        "//beacon-chain/core/transition:go_default_library",
        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
-        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/filters:go_default_library",
+        "//beacon-chain/db/kv:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/forkchoice:go_default_library",
        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
@@ -72,7 +70,6 @@ go_library(
        "//config/params:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/forkchoice:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/payload-attribute:go_default_library",
        "//consensus-types/primitives:go_default_library",
@@ -101,22 +98,26 @@ go_library(
    ],
 )

-go_test(
+test_suite(
    name = "go_default_test",
+    tests = [
+        ":go_raceoff_test",
+        ":go_raceon_test",
+    ],
+)
+
+go_test(
+    name = "go_raceoff_test",
    size = "medium",
    srcs = [
        "blockchain_test.go",
-        "chain_info_norace_test.go",
        "chain_info_test.go",
        "checktags_test.go",
-        "error_test.go",
        "execution_engine_test.go",
        "forkchoice_update_execution_test.go",
        "head_sync_committee_info_test.go",
        "head_test.go",
-        "init_sync_process_block_test.go",
        "init_test.go",
-        "lightclient_test.go",
        "log_test.go",
        "metrics_test.go",
        "mock_test.go",
@@ -125,67 +126,98 @@ go_test(
        "process_block_test.go",
        "receive_attestation_test.go",
        "receive_block_test.go",
-        "service_norace_test.go",
        "service_test.go",
        "setup_test.go",
        "weak_subjectivity_checks_test.go",
    ],
    embed = [":go_default_library"],
    gotags = ["develop"],
-    tags = ["CI_race_detection"],
    deps = [
        "//async/event:go_default_library",
        "//beacon-chain/blockchain/testing:go_default_library",
-        "//beacon-chain/cache:go_default_library",
        "//beacon-chain/cache/depositcache:go_default_library",
        "//beacon-chain/core/blocks:go_default_library",
-        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
-        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
-        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/testing:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/execution/testing:go_default_library",
-        "//beacon-chain/forkchoice:go_default_library",
-        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
        "//beacon-chain/forkchoice/types:go_default_library",
-        "//beacon-chain/operations/attestations:go_default_library",
-        "//beacon-chain/operations/blstoexec:go_default_library",
-        "//beacon-chain/operations/slashings:go_default_library",
-        "//beacon-chain/operations/voluntaryexits:go_default_library",
        "//beacon-chain/p2p:go_default_library",
-        "//beacon-chain/startup:go_default_library",
-        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/state-native:go_default_library",
-        "//beacon-chain/state/stategen:go_default_library",
-        "//config/features:go_default_library",
+        "//beacon-chain/state/stateutil:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/interfaces:go_default_library",
-        "//consensus-types/primitives:go_default_library",
+        "//consensus-types/blocks/testing:go_default_library",
        "//container/trie:go_default_library",
-        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
-        "//proto/engine/v1:go_default_library",
-        "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime/version:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
-        "//time:go_default_library",
-        "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
+        "@in_gopkg_d4l3k_messagediff_v1//:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
+        "@org_golang_x_net//context:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_raceon_test",
+    srcs = [
+        "chain_info_norace_test.go",
+        "checktags_test.go",
+        "init_test.go",
+        "mock_test.go",
+        "receive_block_test.go",
+        "service_norace_test.go",
+        "setup_test.go",
+    ],
+    embed = [":go_default_library"],
+    gc_goopts = [
+        # Go 1.14 enables checkptr by default when building with -race or -msan. There is a pointer
+        # issue in boltdb, so must disable checkptr at compile time. This flag can be removed once
+        # the project is migrated to etcd's version of boltdb and the issue has been fixed.
+        # See: https://github.com/etcd-io/bbolt/issues/187.
+        "-d=checkptr=0",
+    ],
+    gotags = ["develop"],
+    race = "on",
+    tags = ["race_on"],
+    deps = [
+        "//async/event:go_default_library",
+        "//beacon-chain/blockchain/testing:go_default_library",
+        "//beacon-chain/cache/depositcache:go_default_library",
+        "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/transition:go_default_library",
+        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/execution:go_default_library",
+        "//beacon-chain/execution/testing:go_default_library",
+        "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/blocks/testing:go_default_library",
+        "//container/trie:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_ethereum_go_ethereum//:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
-        "@com_github_holiman_uint256//:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
+        "@org_golang_x_net//context:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/chain_info.go
+++ b/beacon-chain/blockchain/chain_info.go
@@ -6,21 +6,19 @@ import (
 	"time"

 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpbv1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"go.opencensus.io/trace"
-
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	f "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/forkchoice"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )

 // ChainInfoFetcher defines a common interface for methods in blockchain service which
@@ -47,7 +45,7 @@ type ForkchoiceFetcher interface {
 	HighestReceivedBlockSlot() primitives.Slot
 	ReceivedBlocksLastEpoch() (uint64, error)
 	InsertNode(context.Context, state.BeaconState, [32]byte) error
-	ForkChoiceDump(context.Context) (*forkchoice.Dump, error)
+	ForkChoiceDump(context.Context) (*ethpbv1.ForkChoiceDump, error)
 	NewSlot(context.Context, primitives.Slot) error
 	ProposerBoost() [32]byte
 }
@@ -77,7 +75,6 @@ type HeadFetcher interface {
 	HeadPublicKeyToValidatorIndex(pubKey [fieldparams.BLSPubkeyLength]byte) (primitives.ValidatorIndex, bool)
 	HeadValidatorIndexToPublicKey(ctx context.Context, index primitives.ValidatorIndex) ([fieldparams.BLSPubkeyLength]byte, error)
 	ChainHeads() ([][32]byte, []primitives.Slot)
-	TargetRootForEpoch([32]byte, primitives.Epoch) ([32]byte, error)
 	HeadSyncCommitteeFetcher
 	HeadDomainFetcher
 }
@@ -336,21 +333,12 @@ func (s *Service) HeadValidatorIndexToPublicKey(_ context.Context, index primiti
 	return v.PublicKey(), nil
 }

-// ForkChoicer returns the forkchoice interface.
-func (s *Service) ForkChoicer() f.ForkChoicer {
-	return s.cfg.ForkChoiceStore
-}
-
 // IsOptimistic returns true if the current head is optimistic.
 func (s *Service) IsOptimistic(_ context.Context) (bool, error) {
 	if slots.ToEpoch(s.CurrentSlot()) < params.BeaconConfig().BellatrixForkEpoch {
 		return false, nil
 	}
 	s.headLock.RLock()
-	if s.head == nil {
-		s.headLock.RUnlock()
-		return false, ErrNilHead
-	}
 	headRoot := s.head.root
 	headSlot := s.head.slot
 	headOptimistic := s.head.optimistic
@@ -476,13 +464,6 @@ func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool,
 	return !isCanonical, nil
 }

-// TargetRootForEpoch wraps the corresponding method in forkchoice
-func (s *Service) TargetRootForEpoch(root [32]byte, epoch primitives.Epoch) ([32]byte, error) {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.TargetRootForEpoch(root, epoch)
-}
-
 // Ancestor returns the block root of an ancestry block from the input block root.
 //
 // Spec pseudocode definition:
@@ -549,17 +530,3 @@ func (s *Service) recoverStateSummary(ctx context.Context, blockRoot [32]byte) (
 func (s *Service) BlockBeingSynced(root [32]byte) bool {
 	return s.blockBeingSynced.isSyncing(root)
 }
-
-// RecentBlockSlot returns block slot form fork choice store
-func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.Slot(root)
-}
-
-// inRegularSync queries the initial sync service to
-// determine if the node is in regular sync or is still
-// syncing to the head of the chain.
-func (s *Service) inRegularSync() bool {
-	return s.cfg.SyncChecker.Synced()
-}
--- a/beacon-chain/blockchain/chain_info_forkchoice.go
+++ b/beacon-chain/blockchain/chain_info_forkchoice.go
@@ -3,9 +3,9 @@ package blockchain
 import (
 	"context"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/forkchoice"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	ethpbv1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
 )

 // CachedHeadRoot returns the corresponding value from Forkchoice
@@ -22,13 +22,6 @@ func (s *Service) GetProposerHead() [32]byte {
 	return s.cfg.ForkChoiceStore.GetProposerHead()
 }

-// ShouldOverrideFCU returns the corresponding value from forkchoice
-func (s *Service) ShouldOverrideFCU() bool {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.ShouldOverrideFCU()
-}
-
 // SetForkChoiceGenesisTime sets the genesis time in Forkchoice
 func (s *Service) SetForkChoiceGenesisTime(timestamp uint64) {
 	s.cfg.ForkChoiceStore.Lock()
@@ -58,7 +51,7 @@ func (s *Service) InsertNode(ctx context.Context, st state.BeaconState, root [32
 }

 // ForkChoiceDump returns the corresponding value from forkchoice
-func (s *Service) ForkChoiceDump(ctx context.Context) (*forkchoice.Dump, error) {
+func (s *Service) ForkChoiceDump(ctx context.Context) (*ethpbv1.ForkChoiceDump, error) {
 	s.cfg.ForkChoiceStore.RLock()
 	defer s.cfg.ForkChoiceStore.RUnlock()
 	return s.cfg.ForkChoiceStore.ForkChoiceDump(ctx)
--- a/beacon-chain/blockchain/chain_info_norace_test.go
+++ b/beacon-chain/blockchain/chain_info_norace_test.go
@@ -4,14 +4,14 @@ import (
 	"context"
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )

 func TestHeadSlot_DataRace(t *testing.T) {
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -5,21 +5,21 @@ import (
 	"testing"
 	"time"

-	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	state_native "github.com/prysmaticlabs/prysm/v4/beacon-chain/state/state-native"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 	"google.golang.org/protobuf/proto"
 )

@@ -429,11 +429,6 @@ func TestService_IsOptimistic(t *testing.T) {
 	opt, err = c.IsOptimistic(ctx)
 	require.NoError(t, err)
 	require.Equal(t, true, opt)
-
-	// If head is nil, for some reason, an error should be returned rather than panic.
-	c = &Service{}
-	_, err = c.IsOptimistic(ctx)
-	require.ErrorIs(t, err, ErrNilHead)
 }

 func TestService_IsOptimisticBeforeBellatrix(t *testing.T) {
--- a/beacon-chain/blockchain/defragment.go
+++ b/beacon-chain/blockchain/defragment.go
@@ -1,27 +0,0 @@
-package blockchain
-
-import (
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
-	"github.com/prysmaticlabs/prysm/v5/time"
-)
-
-var stateDefragmentationTime = promauto.NewSummary(prometheus.SummaryOpts{
-	Name: "head_state_defragmentation_milliseconds",
-	Help: "Milliseconds it takes to defragment the head state",
-})
-
-// This method defragments our state, so that any specific fields which have
-// a higher number of fragmented indexes are reallocated to a new separate slice for
-// that field.
-func (s *Service) defragmentState(st state.BeaconState) {
-	if !features.Get().EnableExperimentalState {
-		return
-	}
-	startTime := time.Now()
-	st.Defragment()
-	elapsedTime := time.Since(startTime)
-	stateDefragmentationTime.Observe(float64(elapsedTime.Milliseconds()))
-}
--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -28,12 +28,8 @@ var (
 	// ErrNotCheckpoint is returned when a given checkpoint is not a
 	// checkpoint in any chain known to forkchoice
 	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")
 )

-var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")
-
 // An invalid block is the block that fails state transition based on the core protocol rules.
 // The beacon node shall not be accepting nor building blocks that branch off from an invalid block.
 // Some examples of invalid blocks are:
--- a/beacon-chain/blockchain/error_test.go
+++ b/beacon-chain/blockchain/error_test.go
@@ -4,7 +4,7 @@ import (
 	"testing"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestIsInvalidBlock(t *testing.T) {
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -7,23 +7,23 @@ import (

 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	payloadattribute "github.com/prysmaticlabs/prysm/v5/consensus-types/payload-attribute"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db/kv"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/execution"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	consensusblocks "github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	payloadattribute "github.com/prysmaticlabs/prysm/v4/consensus-types/payload-attribute"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -32,18 +32,21 @@ const blobCommitmentVersionKZG uint8 = 0x01

 var defaultLatestValidHash = bytesutil.PadTo([]byte{0xff}, 32)

+// notifyForkchoiceUpdateArg is the argument for the forkchoice update notification `notifyForkchoiceUpdate`.
+type notifyForkchoiceUpdateArg struct {
+	headState state.BeaconState
+	headRoot  [32]byte
+	headBlock interfaces.ReadOnlyBeaconBlock
+}
+
 // notifyForkchoiceUpdate signals execution engine the fork choice updates. Execution engine should:
 // 1. Re-organizes the execution payload chain and corresponding state to make head_block_hash the head.
 // 2. Applies finality to the execution state: it irreversibly persists the chain of all execution payloads and corresponding state, up to and including finalized_block_hash.
-func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*enginev1.PayloadIDBytes, error) {
+func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkchoiceUpdateArg) (*enginev1.PayloadIDBytes, error) {
 	ctx, span := trace.StartSpan(ctx, "blockChain.notifyForkchoiceUpdate")
 	defer span.End()

-	if arg.headBlock.IsNil() {
-		log.Error("Head block is nil")
-		return nil, nil
-	}
-	headBlk := arg.headBlock.Block()
+	headBlk := arg.headBlock
 	if headBlk == nil || headBlk.IsNil() || headBlk.Body().IsNil() {
 		log.Error("Head block is nil")
 		return nil, nil
@@ -69,10 +72,11 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		SafeBlockHash:      justifiedHash[:],
 		FinalizedBlockHash: finalizedHash[:],
 	}
-	if arg.attributes == nil {
-		arg.attributes = payloadattribute.EmptyWithVersion(headBlk.Version())
-	}
-	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, arg.attributes)
+
+	nextSlot := s.CurrentSlot() + 1 // Cache payload ID for next slot proposer.
+	hasAttr, attr, proposerId := s.getPayloadAttribute(ctx, arg.headState, nextSlot, arg.headRoot[:])
+
+	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, attr)
 	if err != nil {
 		switch err {
 		case execution.ErrAcceptedSyncingPayloadStatus:
@@ -118,11 +122,10 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 				log.WithError(err).Error("Could not get head state")
 				return nil, nil
 			}
-			pid, err := s.notifyForkchoiceUpdate(ctx, &fcuConfig{
-				headState:  st,
-				headRoot:   r,
-				headBlock:  b,
-				attributes: arg.attributes,
+			pid, err := s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
+				headState: st,
+				headRoot:  r,
+				headBlock: b.Block(),
 			})
 			if err != nil {
 				return nil, err // Returning err because it's recursive here.
@@ -150,18 +153,11 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		log.WithError(err).Error("Could not set head root to valid")
 		return nil, nil
 	}
-	// If the forkchoice update call has an attribute, update the payload ID cache.
-	hasAttr := arg.attributes != nil && !arg.attributes.IsEmpty()
-	nextSlot := s.CurrentSlot() + 1
+	// If the forkchoice update call has an attribute, update the proposer payload ID cache.
 	if hasAttr && payloadID != nil {
 		var pId [8]byte
 		copy(pId[:], payloadID[:])
-		log.WithFields(logrus.Fields{
-			"blockRoot": fmt.Sprintf("%#x", bytesutil.Trunc(arg.headRoot[:])),
-			"headSlot":  headBlk.Slot(),
-			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
-		}).Info("Forkchoice updated with payload attributes for proposal")
-		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
+		s.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(nextSlot, proposerId, pId, arg.headRoot)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
@@ -276,50 +272,56 @@ func (s *Service) pruneInvalidBlock(ctx context.Context, root, parentRoot, lvh [

 // getPayloadAttributes returns the payload attributes for the given state and slot.
 // The attribute is required to initiate a payload build process in the context of an `engine_forkchoiceUpdated` call.
-func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState, slot primitives.Slot, headRoot []byte) payloadattribute.Attributer {
+func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState, slot primitives.Slot, headRoot []byte) (bool, payloadattribute.Attributer, primitives.ValidatorIndex) {
 	emptyAttri := payloadattribute.EmptyWithVersion(st.Version())
-
-	// If it is an epoch boundary then process slots to get the right
-	// shuffling before checking if the proposer is tracked. Otherwise
-	// perform this check before. This is cheap as the NSC has already been updated.
-	var val cache.TrackedValidator
-	var ok bool
-	e := slots.ToEpoch(slot)
-	stateEpoch := slots.ToEpoch(st.Slot())
-	if e == stateEpoch {
-		val, ok = s.trackedProposer(st, slot)
-		if !ok {
-			return emptyAttri
-		}
+	// Root is `[32]byte{}` since we are retrieving proposer ID of a given slot. During insertion at assignment the root was not known.
+	proposerID, _, ok := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(slot, [32]byte{} /* root */)
+	if !ok && !features.Get().PrepareAllPayloads { // There's no need to build attribute if there is no proposer for slot.
+		return false, emptyAttri, 0
 	}
+
+	// Get previous randao.
 	st = st.Copy()
 	if slot > st.Slot() {
 		var err error
 		st, err = transition.ProcessSlotsUsingNextSlotCache(ctx, st, headRoot, slot)
 		if err != nil {
 			log.WithError(err).Error("Could not process slots to get payload attribute")
-			return emptyAttri
+			return false, emptyAttri, 0
 		}
 	}
-	if e > stateEpoch {
-		emptyAttri := payloadattribute.EmptyWithVersion(st.Version())
-		val, ok = s.trackedProposer(st, slot)
-		if !ok {
-			return emptyAttri
-		}
-	}
-	// Get previous randao.
 	prevRando, err := helpers.RandaoMix(st, time.CurrentEpoch(st))
 	if err != nil {
 		log.WithError(err).Error("Could not get randao mix to get payload attribute")
-		return emptyAttri
+		return false, emptyAttri, 0
+	}
+
+	// Get fee recipient.
+	feeRecipient := params.BeaconConfig().DefaultFeeRecipient
+	recipient, err := s.cfg.BeaconDB.FeeRecipientByValidatorID(ctx, proposerID)
+	switch {
+	case errors.Is(err, kv.ErrNotFoundFeeRecipient):
+		if feeRecipient.String() == params.BeaconConfig().EthBurnAddressHex {
+			logrus.WithFields(logrus.Fields{
+				"validatorIndex": proposerID,
+				"burnAddress":    params.BeaconConfig().EthBurnAddressHex,
+			}).Warn("Fee recipient is currently using the burn address, " +
+				"you will not be rewarded transaction fees on this setting. " +
+				"Please set a different eth address as the fee recipient. " +
+				"Please refer to our documentation for instructions")
+		}
+	case err != nil:
+		log.WithError(err).Error("Could not get fee recipient to get payload attribute")
+		return false, emptyAttri, 0
+	default:
+		feeRecipient = recipient
 	}

 	// Get timestamp.
 	t, err := slots.ToTime(uint64(s.genesisTime.Unix()), slot)
 	if err != nil {
 		log.WithError(err).Error("Could not get timestamp to get payload attribute")
-		return emptyAttri
+		return false, emptyAttri, 0
 	}

 	var attr payloadattribute.Attributer
@@ -328,51 +330,51 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 		withdrawals, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
-			return emptyAttri
+			return false, emptyAttri, 0
 		}
 		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV3{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: val.FeeRecipient[:],
+			SuggestedFeeRecipient: feeRecipient.Bytes(),
 			Withdrawals:           withdrawals,
 			ParentBeaconBlockRoot: headRoot,
 		})
 		if err != nil {
 			log.WithError(err).Error("Could not get payload attribute")
-			return emptyAttri
+			return false, emptyAttri, 0
 		}
 	case version.Capella:
 		withdrawals, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
-			return emptyAttri
+			return false, emptyAttri, 0
 		}
 		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV2{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: val.FeeRecipient[:],
+			SuggestedFeeRecipient: feeRecipient.Bytes(),
 			Withdrawals:           withdrawals,
 		})
 		if err != nil {
 			log.WithError(err).Error("Could not get payload attribute")
-			return emptyAttri
+			return false, emptyAttri, 0
 		}
 	case version.Bellatrix:
 		attr, err = payloadattribute.New(&enginev1.PayloadAttributes{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: val.FeeRecipient[:],
+			SuggestedFeeRecipient: feeRecipient.Bytes(),
 		})
 		if err != nil {
 			log.WithError(err).Error("Could not get payload attribute")
-			return emptyAttri
+			return false, emptyAttri, 0
 		}
 	default:
 		log.WithField("version", st.Version()).Error("Could not get payload attribute due to unknown state version")
-		return emptyAttri
+		return false, emptyAttri, 0
 	}

-	return attr
+	return true, attr, proposerID
 }

 // removeInvalidBlockAndState removes the invalid block, blob and its corresponding state from the cache and DB.
@@ -387,9 +389,9 @@ func (s *Service) removeInvalidBlockAndState(ctx context.Context, blkRoots [][32
 			// This is an irreparable condition, it would me a justified or finalized block has become invalid.
 			return err
 		}
-		if err := s.blobStorage.Remove(root); err != nil {
-			// Blobs may not exist for some blocks, leading to deletion failures. Log such errors at debug level.
-			log.WithError(err).Debug("Could not remove blob from blob storage")
+		// No op if the sidecar does not exist.
+		if err := s.cfg.BeaconDB.DeleteBlobSidecars(ctx, root); err != nil {
+			return err
 		}
 	}
 	return nil
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -7,29 +7,30 @@ import (

 	"github.com/ethereum/go-ethereum/common"
 	gethtypes "github.com/ethereum/go-ethereum/core/types"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
-	mockExecution "github.com/prysmaticlabs/prysm/v5/beacon-chain/execution/testing"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
-	bstate "github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/execution"
+	mockExecution "github.com/prysmaticlabs/prysm/v4/beacon-chain/execution/testing"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	bstate "github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	state_native "github.com/prysmaticlabs/prysm/v4/beacon-chain/state/state-native"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	consensusblocks "github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
+	logTest "github.com/sirupsen/logrus/hooks/test"
 )

 func Test_NotifyForkchoiceUpdate_GetPayloadAttrErrorCanContinue(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

 	altairBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockAltair())
@@ -56,14 +57,11 @@ func Test_NotifyForkchoiceUpdate_GetPayloadAttrErrorCanContinue(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))

-	sb := &ethpb.SignedBeaconBlockBellatrix{
-		Block: &ethpb.BeaconBlockBellatrix{
-			Body: &ethpb.BeaconBlockBodyBellatrix{
-				ExecutionPayload: &v1.ExecutionPayload{},
-			},
+	b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
+		Body: &ethpb.BeaconBlockBodyBellatrix{
+			ExecutionPayload: &v1.ExecutionPayload{},
 		},
-	}
-	b, err := consensusblocks.NewSignedBeaconBlock(sb)
+	})
 	require.NoError(t, err)

 	pid := &v1.PayloadIDBytes{1}
@@ -75,20 +73,20 @@ func Test_NotifyForkchoiceUpdate_GetPayloadAttrErrorCanContinue(t *testing.T) {
 	// Intentionally generate a bad state such that `hash_tree_root` fails during `process_slot`
 	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
 	require.NoError(t, err)
-	arg := &fcuConfig{
+	arg := &notifyForkchoiceUpdateArg{
 		headState: s,
 		headRoot:  [32]byte{},
 		headBlock: b,
 	}

-	service.cfg.PayloadIDCache.Set(1, [32]byte{}, [8]byte{})
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(1, 0, [8]byte{}, [32]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.
 }

 func Test_NotifyForkchoiceUpdate(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

 	altairBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockAltair())
@@ -116,7 +114,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {

 	tests := []struct {
 		name             string
-		blk              interfaces.ReadOnlySignedBeaconBlock
+		blk              interfaces.ReadOnlyBeaconBlock
 		headRoot         [32]byte
 		finalizedRoot    [32]byte
 		justifiedRoot    [32]byte
@@ -125,24 +123,24 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 	}{
 		{
 			name: "phase0 block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlock{Block: &ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}}})
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}})
 				require.NoError(t, err)
 				return b
 			}(),
 		},
 		{
 			name: "altair block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockAltair{Block: &ethpb.BeaconBlockAltair{Body: &ethpb.BeaconBlockBodyAltair{}}})
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockAltair{Body: &ethpb.BeaconBlockBodyAltair{}})
 				require.NoError(t, err)
 				return b
 			}(),
 		},
 		{
 			name: "not execution block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockBellatrix{Block: &ethpb.BeaconBlockBellatrix{
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{
 							ParentHash:    make([]byte, fieldparams.RootLength),
@@ -151,25 +149,23 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 							ReceiptsRoot:  make([]byte, fieldparams.RootLength),
 							LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
 							PrevRandao:    make([]byte, fieldparams.RootLength),
-							ExtraData:     make([]byte, 0),
 							BaseFeePerGas: make([]byte, fieldparams.RootLength),
 							BlockHash:     make([]byte, fieldparams.RootLength),
-							Transactions:  make([][]byte, 0),
 						},
 					},
-				}})
+				})
 				require.NoError(t, err)
 				return b
 			}(),
 		},
 		{
 			name: "happy case: finalized root is altair block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockBellatrix{Block: &ethpb.BeaconBlockBellatrix{
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
-				}})
+				})
 				require.NoError(t, err)
 				return b
 			}(),
@@ -178,12 +174,12 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		},
 		{
 			name: "happy case: finalized root is bellatrix block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockBellatrix{Block: &ethpb.BeaconBlockBellatrix{
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
-				}})
+				})
 				require.NoError(t, err)
 				return b
 			}(),
@@ -192,12 +188,12 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		},
 		{
 			name: "forkchoice updated with optimistic block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockBellatrix{Block: &ethpb.BeaconBlockBellatrix{
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
-				}})
+				})
 				require.NoError(t, err)
 				return b
 			}(),
@@ -207,12 +203,12 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		},
 		{
 			name: "forkchoice updated with invalid block",
-			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				b, err := consensusblocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockBellatrix{Block: &ethpb.BeaconBlockBellatrix{
+			blk: func() interfaces.ReadOnlyBeaconBlock {
+				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
-				}})
+				})
 				require.NoError(t, err)
 				return b
 			}(),
@@ -230,7 +226,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 			st, _ := util.DeterministicGenesisState(t, 1)
 			require.NoError(t, beaconDB.SaveState(ctx, st, tt.finalizedRoot))
 			require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, tt.finalizedRoot))
-			arg := &fcuConfig{
+			arg := &notifyForkchoiceUpdateArg{
 				headState: st,
 				headRoot:  tt.headRoot,
 				headBlock: tt.blk,
@@ -250,7 +246,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 }

 func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

 	// Prepare blocks
@@ -310,9 +306,9 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {

 	require.NoError(t, beaconDB.SaveState(ctx, st, bra))
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bra))
-	a := &fcuConfig{
+	a := &notifyForkchoiceUpdateArg{
 		headState: st,
-		headBlock: wbd,
+		headBlock: wbd.Block(),
 		headRoot:  brd,
 	}
 	_, err = service.notifyForkchoiceUpdate(ctx, a)
@@ -338,7 +334,7 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 // 3. the blockchain package calls fcu to obtain heads G -> F -> D.

 func Test_NotifyForkchoiceUpdateRecursive_DoublyLinkedTree(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

 	// Prepare blocks
@@ -447,9 +443,9 @@ func Test_NotifyForkchoiceUpdateRecursive_DoublyLinkedTree(t *testing.T) {

 	require.NoError(t, beaconDB.SaveState(ctx, st, bra))
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bra))
-	a := &fcuConfig{
+	a := &notifyForkchoiceUpdateArg{
 		headState: st,
-		headBlock: wbg,
+		headBlock: wbg.Block(),
 		headRoot:  brg,
 	}
 	_, err = service.notifyForkchoiceUpdate(ctx, a)
@@ -471,7 +467,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 	cfg := params.BeaconConfig()
 	cfg.TerminalTotalDifficulty = "2"
 	params.OverrideBeaconConfig(cfg)
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx, fcs := tr.ctx, tr.fcs

 	phase0State, _ := util.DeterministicGenesisState(t, 1)
@@ -496,10 +492,8 @@ func Test_NotifyNewPayload(t *testing.T) {
 					ReceiptsRoot:  make([]byte, fieldparams.RootLength),
 					LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
 					PrevRandao:    make([]byte, fieldparams.RootLength),
-					ExtraData:     make([]byte, 0),
 					BaseFeePerGas: make([]byte, fieldparams.RootLength),
 					BlockHash:     make([]byte, fieldparams.RootLength),
-					Transactions:  make([][]byte, 0),
 				},
 			},
 		},
@@ -601,10 +595,8 @@ func Test_NotifyNewPayload(t *testing.T) {
 								ReceiptsRoot:  make([]byte, fieldparams.RootLength),
 								LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
 								PrevRandao:    make([]byte, fieldparams.RootLength),
-								ExtraData:     make([]byte, 0),
 								BaseFeePerGas: make([]byte, fieldparams.RootLength),
 								BlockHash:     make([]byte, fieldparams.RootLength),
-								Transactions:  make([][]byte, 0),
 							},
 						},
 					},
@@ -717,7 +709,7 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	cfg.TerminalTotalDifficulty = "2"
 	params.OverrideBeaconConfig(cfg)

-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx := tr.ctx

 	bellatrixState, _ := util.DeterministicGenesisStateBellatrix(t, 2)
@@ -785,70 +777,83 @@ func Test_reportInvalidBlock(t *testing.T) {
 }

 func Test_GetPayloadAttribute(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx := tr.ctx

 	st, _ := util.DeterministicGenesisStateBellatrix(t, 1)
-	attr := service.getPayloadAttribute(ctx, st, 0, []byte{})
-	require.Equal(t, true, attr.IsEmpty())
+	hasPayload, _, vId := service.getPayloadAttribute(ctx, st, 0, []byte{})
+	require.Equal(t, false, hasPayload)
+	require.Equal(t, primitives.ValidatorIndex(0), vId)

-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
 	// Cache hit, advance state, no fee recipient
+	suggestedVid := primitives.ValidatorIndex(1)
 	slot := primitives.Slot(1)
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hook := logTest.NewGlobal()
+	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")

 	// Cache hit, advance state, has fee recipient
 	suggestedAddr := common.HexToAddress("123")
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []primitives.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
 }

 func Test_GetPayloadAttribute_PrepareAllPayloads(t *testing.T) {
+	hook := logTest.NewGlobal()
 	resetCfg := features.InitWithReset(&features.Flags{
 		PrepareAllPayloads: true,
 	})
 	defer resetCfg()

-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx := tr.ctx

 	st, _ := util.DeterministicGenesisStateBellatrix(t, 1)
-	attr := service.getPayloadAttribute(ctx, st, 0, []byte{})
-	require.Equal(t, false, attr.IsEmpty())
+	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, 0, []byte{})
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, primitives.ValidatorIndex(0), vId)
 	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")
 }

 func Test_GetPayloadAttributeV2(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx := tr.ctx

 	st, _ := util.DeterministicGenesisStateCapella(t, 1)
-	attr := service.getPayloadAttribute(ctx, st, 0, []byte{})
-	require.Equal(t, true, attr.IsEmpty())
+	hasPayload, _, vId := service.getPayloadAttribute(ctx, st, 0, []byte{})
+	require.Equal(t, false, hasPayload)
+	require.Equal(t, primitives.ValidatorIndex(0), vId)

 	// Cache hit, advance state, no fee recipient
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
+	suggestedVid := primitives.ValidatorIndex(1)
 	slot := primitives.Slot(1)
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hook := logTest.NewGlobal()
+	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")
 	a, err := attr.Withdrawals()
 	require.NoError(t, err)
 	require.Equal(t, 0, len(a))

 	// Cache hit, advance state, has fee recipient
 	suggestedAddr := common.HexToAddress("123")
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []primitives.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
 	a, err = attr.Withdrawals()
 	require.NoError(t, err)
@@ -856,30 +861,35 @@ func Test_GetPayloadAttributeV2(t *testing.T) {
 }

 func Test_GetPayloadAttributeDeneb(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx := tr.ctx

 	st, _ := util.DeterministicGenesisStateDeneb(t, 1)
-	attr := service.getPayloadAttribute(ctx, st, 0, []byte{})
-	require.Equal(t, true, attr.IsEmpty())
+	hasPayload, _, vId := service.getPayloadAttribute(ctx, st, 0, []byte{})
+	require.Equal(t, false, hasPayload)
+	require.Equal(t, primitives.ValidatorIndex(0), vId)

 	// Cache hit, advance state, no fee recipient
+	suggestedVid := primitives.ValidatorIndex(1)
 	slot := primitives.Slot(1)
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hook := logTest.NewGlobal()
+	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")
 	a, err := attr.Withdrawals()
 	require.NoError(t, err)
 	require.Equal(t, 0, len(a))

 	// Cache hit, advance state, has fee recipient
 	suggestedAddr := common.HexToAddress("123")
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []primitives.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
 	a, err = attr.Withdrawals()
 	require.NoError(t, err)
@@ -1102,35 +1112,3 @@ func TestKZGCommitmentToVersionedHashes(t *testing.T) {
 	require.Equal(t, vhs[0].String(), vh0)
 	require.Equal(t, vhs[1].String(), vh1)
 }
-
-func TestComputePayloadAttribute(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
-	ctx := tr.ctx
-
-	st, _ := util.DeterministicGenesisStateBellatrix(t, 1)
-
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
-	// Cache hit, advance state, no fee recipient
-	slot := primitives.Slot(1)
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	cfg := &postBlockProcessConfig{
-		ctx:       ctx,
-		blockRoot: [32]byte{'a'},
-	}
-	fcu := &fcuConfig{
-		headState:     st,
-		proposingSlot: slot,
-		headRoot:      [32]byte{},
-	}
-	require.NoError(t, service.computePayloadAttributes(cfg, fcu))
-	require.Equal(t, false, fcu.attributes.IsEmpty())
-	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(fcu.attributes.SuggestedFeeRecipient()).String())
-
-	// Cache hit, advance state, has fee recipient
-	suggestedAddr := common.HexToAddress("123")
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	require.NoError(t, service.computePayloadAttributes(cfg, fcu))
-	require.Equal(t, false, fcu.attributes.IsEmpty())
-	require.Equal(t, suggestedAddr, common.BytesToAddress(fcu.attributes.SuggestedFeeRecipient()))
-}
--- a/beacon-chain/blockchain/forkchoice_update_execution.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution.go
@@ -6,17 +6,22 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	payloadattribute "github.com/prysmaticlabs/prysm/v5/consensus-types/payload-attribute"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )

+func (s *Service) isNewProposer(slot primitives.Slot) bool {
+	_, _, ok := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(slot, [32]byte{} /* root */)
+	return ok || features.Get().PrepareAllPayloads
+}
+
 func (s *Service) isNewHead(r [32]byte) bool {
 	s.headLock.RLock()
 	defer s.headLock.RUnlock()
@@ -44,69 +49,48 @@ func (s *Service) getStateAndBlock(ctx context.Context, r [32]byte) (state.Beaco
 	return headState, newHeadBlock, nil
 }

-type fcuConfig struct {
-	headState     state.BeaconState
-	headBlock     interfaces.ReadOnlySignedBeaconBlock
-	headRoot      [32]byte
-	proposingSlot primitives.Slot
-	attributes    payloadattribute.Attributer
-}
-
-// sendFCU handles the logic to notify the engine of a forckhoice update
-// for the first time when processing an incoming block during regular sync. It
-// always updates the shuffling caches and handles epoch transitions when the
-// incoming block is late, preparing payload attributes in this case while it
-// only sends a message with empty attributes for early blocks.
-func (s *Service) sendFCU(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) error {
-	if !s.isNewHead(cfg.headRoot) {
-		return nil
-	}
-	if fcuArgs.attributes != nil && !fcuArgs.attributes.IsEmpty() && s.shouldOverrideFCU(cfg.headRoot, s.CurrentSlot()+1) {
-		return nil
-	}
-	return s.forkchoiceUpdateWithExecution(cfg.ctx, fcuArgs)
-}
-
-// sendFCUWithAttributes computes the payload attributes and sends an FCU message
-// to the engine if needed
-func (s *Service) sendFCUWithAttributes(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) {
-	slotCtx, cancel := context.WithTimeout(context.Background(), slotDeadline)
-	defer cancel()
-	cfg.ctx = slotCtx
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	if err := s.computePayloadAttributes(cfg, fcuArgs); err != nil {
-		log.WithError(err).Error("could not compute payload attributes")
-		return
-	}
-	if fcuArgs.attributes.IsEmpty() {
-		return
-	}
-	if _, err := s.notifyForkchoiceUpdate(cfg.ctx, fcuArgs); err != nil {
-		log.WithError(err).Error("could not update forkchoice with payload attributes for proposal")
-	}
-}
-
 // fockchoiceUpdateWithExecution is a wrapper around notifyForkchoiceUpdate. It decides whether a new call to FCU should be made.
-func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuConfig) error {
+// it returns true if the new head is updated
+func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, newHeadRoot [32]byte, proposingSlot primitives.Slot) (bool, error) {
 	_, span := trace.StartSpan(ctx, "beacon-chain.blockchain.forkchoiceUpdateWithExecution")
 	defer span.End()
 	// Note: Use the service context here to avoid the parent context being ended during a forkchoice update.
 	ctx = trace.NewContext(s.ctx, span)
-	_, err := s.notifyForkchoiceUpdate(ctx, args)
+
+	isNewHead := s.isNewHead(newHeadRoot)
+	if !isNewHead {
+		return false, nil
+	}
+	isNewProposer := s.isNewProposer(proposingSlot)
+	if isNewProposer && !features.Get().DisableReorgLateBlocks {
+		if s.shouldOverrideFCU(newHeadRoot, proposingSlot) {
+			return false, nil
+		}
+	}
+	headState, headBlock, err := s.getStateAndBlock(ctx, newHeadRoot)
 	if err != nil {
-		return errors.Wrap(err, "could not notify forkchoice update")
+		log.WithError(err).Error("Could not get forkchoice update argument")
+		return false, nil
 	}

-	if err := s.saveHead(ctx, args.headRoot, args.headBlock, args.headState); err != nil {
+	_, err = s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
+		headState: headState,
+		headRoot:  newHeadRoot,
+		headBlock: headBlock.Block(),
+	})
+	if err != nil {
+		return false, errors.Wrap(err, "could not notify forkchoice update")
+	}
+
+	if err := s.saveHead(ctx, newHeadRoot, headBlock, headState); err != nil {
 		log.WithError(err).Error("could not save head")
 	}

 	// Only need to prune attestations from pool if the head has changed.
-	if err := s.pruneAttsFromPool(args.headBlock); err != nil {
+	if err := s.pruneAttsFromPool(headBlock); err != nil {
 		log.WithError(err).Error("could not prune attestations from pool")
 	}
-	return nil
+	return true, nil
 }

 // shouldOverrideFCU checks whether the incoming block is still subject to being
--- a/beacon-chain/blockchain/forkchoice_update_execution_test.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution_test.go
@@ -5,18 +5,27 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	mockExecution "github.com/prysmaticlabs/prysm/v5/beacon-chain/execution/testing"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
+	mockExecution "github.com/prysmaticlabs/prysm/v4/beacon-chain/execution/testing"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

+func TestService_isNewProposer(t *testing.T) {
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	require.Equal(t, false, service.isNewProposer(service.CurrentSlot()+1))
+
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(service.CurrentSlot()+1, 0, [8]byte{}, [32]byte{} /* root */)
+	require.Equal(t, true, service.isNewProposer(service.CurrentSlot()+1))
+}
+
 func TestService_isNewHead(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
@@ -58,14 +67,33 @@ func TestService_getHeadStateAndBlock(t *testing.T) {
 }

 func TestService_forkchoiceUpdateWithExecution_exceptionalCases(t *testing.T) {
+	hook := logTest.NewGlobal()
 	ctx := context.Background()
 	opts := testServiceOptsWithDB(t)

 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	service.cfg.PayloadIDCache = cache.NewPayloadIDCache()
-	service.cfg.TrackedValidatorsCache = cache.NewTrackedValidatorsCache()
+	service.cfg.ProposerSlotIndexCache = cache.NewProposerPayloadIDsCache()
+	_, err = service.forkchoiceUpdateWithExecution(ctx, service.headRoot(), service.CurrentSlot()+1)
+	require.NoError(t, err)
+	hookErr := "could not notify forkchoice update"
+	invalidStateErr := "could not get state summary: could not find block in DB"
+	require.LogsDoNotContain(t, hook, invalidStateErr)
+	require.LogsDoNotContain(t, hook, hookErr)
+	gb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	require.NoError(t, err)
+	require.NoError(t, service.saveInitSyncBlock(ctx, [32]byte{'a'}, gb))
+	_, err = service.forkchoiceUpdateWithExecution(ctx, [32]byte{'a'}, service.CurrentSlot()+1)
+	require.NoError(t, err)
+	require.LogsContain(t, hook, invalidStateErr)

+	hook.Reset()
+	service.head = &head{
+		root:  [32]byte{'a'},
+		block: nil, /* should not panic if notify head uses correct head */
+	}
+
+	// Block in Cache
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 2
 	wsb, err := blocks.NewSignedBeaconBlock(b)
@@ -79,7 +107,13 @@ func TestService_forkchoiceUpdateWithExecution_exceptionalCases(t *testing.T) {
 		block: wsb,
 		state: st,
 	}
-	service.cfg.PayloadIDCache.Set(2, [32]byte{2}, [8]byte{1})
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(2, 1, [8]byte{1}, [32]byte{2})
+	_, err = service.forkchoiceUpdateWithExecution(ctx, r1, service.CurrentSlot())
+	require.NoError(t, err)
+	require.LogsDoNotContain(t, hook, invalidStateErr)
+	require.LogsDoNotContain(t, hook, hookErr)
+
+	// Block in DB
 	b = util.NewBeaconBlock()
 	b.Block.Slot = 3
 	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b)
@@ -91,22 +125,25 @@ func TestService_forkchoiceUpdateWithExecution_exceptionalCases(t *testing.T) {
 		block: wsb,
 		state: st,
 	}
-	service.cfg.PayloadIDCache.Set(2, [32]byte{2}, [8]byte{1})
-	args := &fcuConfig{
-		headState:     st,
-		headRoot:      r1,
-		headBlock:     wsb,
-		proposingSlot: service.CurrentSlot() + 1,
-	}
-	require.NoError(t, service.forkchoiceUpdateWithExecution(ctx, args))
-
-	payloadID, has := service.cfg.PayloadIDCache.PayloadID(2, [32]byte{2})
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(2, 1, [8]byte{1}, [32]byte{2})
+	_, err = service.forkchoiceUpdateWithExecution(ctx, r1, service.CurrentSlot()+1)
+	require.NoError(t, err)
+	require.LogsDoNotContain(t, hook, invalidStateErr)
+	require.LogsDoNotContain(t, hook, hookErr)
+	vId, payloadID, has := service.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(2, [32]byte{2})
 	require.Equal(t, true, has)
-	require.Equal(t, primitives.PayloadID{1}, payloadID)
+	require.Equal(t, primitives.ValidatorIndex(1), vId)
+	require.Equal(t, [8]byte{1}, payloadID)
+
+	// Test zero headRoot returns immediately.
+	headRoot := service.headRoot()
+	_, err = service.forkchoiceUpdateWithExecution(ctx, [32]byte{}, service.CurrentSlot()+1)
+	require.NoError(t, err)
+	require.Equal(t, service.headRoot(), headRoot)
 }

 func TestService_forkchoiceUpdateWithExecution_SameHeadRootNewProposer(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t)
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

 	altairBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockAltair())
@@ -145,14 +182,10 @@ func TestService_forkchoiceUpdateWithExecution_SameHeadRootNewProposer(t *testin
 	service.head.root = r
 	service.head.block = sb
 	service.head.state = st
-	service.cfg.PayloadIDCache.Set(service.CurrentSlot()+1, [32]byte{} /* root */, [8]byte{})
-	args := &fcuConfig{
-		headState:     st,
-		headBlock:     sb,
-		headRoot:      r,
-		proposingSlot: service.CurrentSlot() + 1,
-	}
-	require.NoError(t, service.forkchoiceUpdateWithExecution(ctx, args))
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(service.CurrentSlot()+1, 0, [8]byte{}, [32]byte{} /* root */)
+	_, err = service.forkchoiceUpdateWithExecution(ctx, r, service.CurrentSlot()+1)
+	require.NoError(t, err)
+
 }

 func TestShouldOverrideFCU(t *testing.T) {
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Kasey Kirkham	edbf5d11d1	refactor to match updated design	2023-11-02 13:32:55 -05:00
Kasey Kirkham	1148d96313	WIP: changes for 3531	2023-11-01 13:13:11 -05:00
Kasey Kirkham	daf5e9b286	get rid of double referencing in error types	2023-10-30 09:15:51 -05:00
Kasey Kirkham	309a863358	errors.As wants a ref	2023-10-27 17:32:09 -05:00
Kasey Kirkham	15b88ed7f2	drop the cache if the kzg commitment fails	2023-10-27 17:22:16 -05:00
Kasey Kirkham	4b4855d65c	return custom missing/mismatch errors; unit tests	2023-10-27 17:10:07 -05:00
Kasey Kirkham	03564ee93b	more tests	2023-10-26 19:35:01 -05:00
Kasey Kirkham	96541c2c6c	gazelle and test fixes	2023-10-26 18:54:11 -05:00
Kasey Kirkham	0bc55339a7	remove partial saving/checking	2023-10-26 16:44:22 -05:00
Kasey Kirkham	2618852090	lint	2023-10-26 11:07:37 -05:00
Kasey Kirkham	fb3e42c1b3	moving things around and comments	2023-10-26 10:24:03 -05:00
Kasey Kirkham	0e2a9d0d82	simplify	2023-10-26 10:24:03 -05:00
Kasey Kirkham	6573cccf1d	significant rewrite for db cache blocking variant	2023-10-26 10:24:03 -05:00
Kasey Kirkham	a89727f38c	same cache usable for init and reg sync the goal isn't for the 2 flavors of sync to share the same cache, because they have different needs, but for them to follow the same procedure and share as much code as possible.	2023-10-26 10:24:03 -05:00
Kasey Kirkham	5e1fb15c40	DA check before blob saving for init-sync	2023-10-26 10:24:03 -05:00
@@ -1 +1 @@
 .0.0
 .3.2