Hack asn-util. Ref: https://github.com/libp2p/go-libp2p/issues/2664

2026-01-11 06:18:05 -05:00 · 2023-12-11 09:21:18 -06:00
2636 changed files with 43175 additions and 55898 deletions
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-7.0.0
+6.4.0
--- a/.buildkite-bazelrc
+++ b/.buildkite-bazelrc
@@ -10,7 +10,7 @@

 # Prysm specific remote-cache properties.
 build:remote-cache --remote_download_minimal
-build:remote-cache --remote_build_event_upload=minimal
+build:remote-cache --experimental_remote_build_event_upload=minimal
 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
--- 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:1.20-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
@@ -5,7 +5,7 @@ on:
    branches: [ master ]
  pull_request:
    branches: [ '*' ]
-  merge_group:
+  merge_group: 
    types: [checks_requested]

 jobs:
@@ -28,10 +28,10 @@ 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
@@ -45,16 +45,16 @@ 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 +64,7 @@ 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
@@ -12,7 +12,7 @@ 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
@@ -126,7 +126,7 @@ STATICCHECK_ANALYZERS = [
    "sa4003",
    "sa4004",
    "sa4005",
-    "sa4006",
+    # "sa4006", # TODO: Fix violations of unused arguments.
    "sa4008",
    "sa4009",
    "sa4010",
@@ -172,7 +172,7 @@ STATICCHECK_ANALYZERS = [
    "sa6006",
    "sa9001",
    "sa9002",
-    #"sa9003", # Doesn't build. See https://github.com/dominikh/go-tools/pull/1483
+    #"sa9003", # Doesn't build
    "sa9004",
    "sa9005",
    "sa9006",
@@ -194,6 +194,33 @@ nogo(
    config = ":nogo_config_with_excludes",
    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 +236,6 @@ 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": [],
--- 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/162
+++ b/162
@@ -96,36 +96,11 @@ 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
-)
-
-http_archive(
-    name = "aspect_bazel_lib",
-    sha256 = "f5ea76682b209cc0bd90d0f5a3b26d2f7a6a2885f0c5f615e72913f4805dbb0d",
-    strip_prefix = "bazel-lib-2.5.0",
-    url = "https://github.com/aspect-build/bazel-lib/releases/download/v2.5.0/bazel-lib-v2.5.0.tar.gz",
-)
-
-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",
@@ -158,10 +133,6 @@ http_archive(
    ],
 )

-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(
@@ -177,16 +148,67 @@ 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,
 )
@@ -200,7 +222,7 @@ 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",
 )

@@ -241,9 +263,7 @@ 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.7-hotfix"
+consensus_spec_version = "v1.4.0-beta.3"

 bls_test_version = "v0.1.1"

@@ -259,8 +279,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "c282c0f86f23f3d2e0f71f5975769a4077e62a7e3c7382a16bd26a7e589811a0",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_test_version,
+    sha256 = "67ae5b8fc368853da23d4297e480a4b7f4722fb970d1c7e2b6a5b7faef9cb907",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

 http_archive(
@@ -275,8 +295,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "4649c35aa3b8eb0cfdc81bee7c05649f90ef36bede5b0513e1f2e8baf37d6033",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_test_version,
+    sha256 = "82474f29fff4abd09fb1e71bafa98827e2573cf0ad02cf119610961831dc3bb5",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

 http_archive(
@@ -291,8 +311,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "c5a03f724f757456ffaabd2a899992a71d2baf45ee4db65ca3518f2b7ee928c8",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_test_version,
+    sha256 = "60e4b6eb6c341daab7ee5614a8e3f28567247c504c593b951bfe919622c8ef8f",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

 http_archive(
@@ -306,7 +326,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "049c29267310e6b88280f4f834a75866c2f5b9036fa97acb9d9c6db8f64d9118",
+    sha256 = "fdab9756c93a250219ff6a10d5a9faee1e2e6878a14508410409e307362c6991",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -337,25 +357,9 @@ 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(
@@ -369,17 +373,17 @@ 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",
    ],
 )

@@ -413,6 +417,24 @@ 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
@@ -6,6 +6,6 @@ go_library(
        "constants.go",
        "headers.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api",
+    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 +7,16 @@ 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/eth/beacon:go_default_library",
+        "//beacon-chain/rpc/eth/config:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
+        "//beacon-chain/rpc/prysm/beacon:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives: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"
 )
@@ -108,10 +108,10 @@ func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, er
 	}

 	log.
-		WithField("blockSlot", b.Block().Slot()).
-		WithField("stateSlot", s.Slot()).
-		WithField("stateRoot", hexutil.Encode(sr[:])).
-		WithField("blockRoot", hexutil.Encode(br[:])).
+		WithField("block_slot", b.Block().Slot()).
+		WithField("state_slot", s.Slot()).
+		WithField("state_root", hexutil.Encode(sr[:])).
+		WithField("block_root", hexutil.Encode(br[:])).
 		Info("Downloaded checkpoint sync state and block.")
 	return &OriginData{
 		st: s,
--- 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
@@ -15,13 +15,16 @@ import (

 	"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/api/client"
+	"github.com/prysmaticlabs/prysm/v4/api/server"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/beacon"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/config"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	apibeacon "github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/prysm/beacon"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/network/forks"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	log "github.com/sirupsen/logrus"
 )

@@ -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) (*config.GetSpecResponse, error) {
 	body, err := c.Get(ctx, getConfigSpecPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting configSpecPath")
 	}
-	fsr := &structs.GetSpecResponse{}
+	fsr := &config.GetSpecResponse{}
 	err = json.Unmarshal(body, fsr)
 	if err != nil {
 		return nil, err
@@ -256,7 +259,7 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 	if err != nil {
 		return nil, err
 	}
-	v := &structs.GetWeakSubjectivityResponse{}
+	v := &apibeacon.GetWeakSubjectivityResponse{}
 	err = json.Unmarshal(body, v)
 	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 {
@@ -310,8 +313,8 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*stru
 		for _, failure := range errorJson.Failures {
 			w := request[failure.Index].Message
 			log.WithFields(log.Fields{
-				"validatorIndex":    w.ValidatorIndex,
-				"withdrawalAddress": w.ToExecutionAddress,
+				"validator_index":    w.ValidatorIndex,
+				"withdrawal_address": w.ToExecutionAddress,
 			}).Error(failure.Message)
 		}
 		return errors.Errorf("POST error %d: %s", errorJson.Code, errorJson.Message)
@@ -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",
@@ -40,7 +40,7 @@ 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 +3,11 @@ 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"
+	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.
@@ -165,7 +165,7 @@ 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 --
@@ -249,7 +249,7 @@ 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 --
--- 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 +13,15 @@ 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"
+	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"
 )
@@ -57,8 +56,8 @@ func (*requestLogger) observe(r *http.Request) (e error) {
 	b := bytes.NewBuffer(nil)
 	if r.Body == nil {
 		log.WithFields(log.Fields{
-			"bodyBase64": "(nil value)",
-			"url":        r.URL.String(),
+			"body-base64": "(nil value)",
+			"url":         r.URL.String(),
 		}).Info("builder http request")
 		return nil
 	}
@@ -74,8 +73,8 @@ func (*requestLogger) observe(r *http.Request) (e error) {
 	}
 	r.Body = io.NopCloser(b)
 	log.WithFields(log.Fields{
-		"bodyBase64": string(body),
-		"url":        r.URL.String(),
+		"body-base64": string(body),
+		"url":         r.URL.String(),
 	}).Info("builder http request")

 	return nil
@@ -267,9 +266,9 @@ 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])
+		vs[i] = shared.SignedValidatorRegistrationFromConsensus(svr[i])
 	}
 	body, err := json.Marshal(vs)
 	if err != nil {
@@ -294,7 +293,7 @@ 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 +330,7 @@ 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 +357,7 @@ 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")
 		}
@@ -368,7 +367,7 @@ 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.SignedBlindedBeaconBlockDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockDeneb{Message: psb.Message, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockDeneb{Message: psb.Message, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockDeneb to json marshalable type")
 		}
@@ -395,7 +394,7 @@ 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")
 		}
@@ -424,26 +423,26 @@ 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)
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -13,15 +13,15 @@ import (
 	"testing"

 	"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"
+	"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"
 )

@@ -275,24 +275,7 @@ func TestClient_GetHeader(t *testing.T) {
 			require.Equal(t, len(kcgCommitments[i]) == 48, true)
 		}
 	})
-	t.Run("deneb, too many kzg commitments", func(t *testing.T) {
-		hc := &http.Client{
-			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
-				require.Equal(t, expectedPath, r.URL.Path)
-				return &http.Response{
-					StatusCode: http.StatusOK,
-					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebTooManyBlobs)),
-					Request:    r.Clone(ctx),
-				}, nil
-			}),
-		}
-		c := &Client{
-			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)
-	})
+
 	t.Run("unsupported version", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -376,7 +359,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 			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.SignedBlindedBeaconBlockDeneb
 				err := json.NewDecoder(r.Body).Decode(&req)
 				require.NoError(t, err)
 				block, err := req.ToConsensus()
@@ -429,7 +412,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		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)
 		require.ErrorIs(t, err, errNotBlinded)
--- 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.
--- 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")
@@ -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 {
@@ -908,9 +869,6 @@ 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 {
@@ -1063,16 +1021,6 @@ 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 +1035,9 @@ 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 +1052,6 @@ 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 +38,7 @@ func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
 		},
 		Signature: make([]byte, 96),
 	}
-	a := structs.SignedValidatorRegistrationFromConsensus(svr)
+	a := shared.SignedValidatorRegistrationFromConsensus(svr)
 	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 +55,7 @@ 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)
 		}
@@ -209,39 +209,6 @@ 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 +628,6 @@ 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 +1004,7 @@ func TestExecutionPayloadResponseCapellaToProto(t *testing.T) {
 		},
 	}
 	require.DeepEqual(t, expected, p)
+
 }

 func TestExecutionPayloadResponseDenebToProto(t *testing.T) {
@@ -1260,27 +1083,7 @@ 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 +1521,7 @@ 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 +1551,7 @@ 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
@@ -3,7 +3,7 @@ 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",
--- a/api/client/validator/client.go
+++ b/api/client/validator/client.go
@@ -7,8 +7,8 @@ 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"
 )

 const (
--- a/api/constants.go
+++ b/api/constants.go
@@ -1,7 +1,3 @@
 package api

-const (
-	WebUrlPrefix        = "/v2/validator/"
-	WebApiUrlPrefix     = "/api/v2/validator/"
-	KeymanagerApiPrefix = "/eth/v1"
-)
+const WebUrlPrefix = "/v2/validator/"
--- a/api/gateway/BUILD.bazel
+++ b/api/gateway/BUILD.bazel
@@ -8,7 +8,7 @@ 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__",
--- a/api/gateway/gateway.go
+++ b/api/gateway/gateway.go
@@ -11,8 +11,8 @@ import (
 	"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/server"
+	"github.com/prysmaticlabs/prysm/v4/runtime"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
--- a/api/gateway/gateway_test.go
+++ b/api/gateway/gateway_test.go
@@ -10,9 +10,9 @@ 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/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"
 )
--- 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
@@ -7,7 +7,7 @@ go_library(
        "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",
--- a/api/server/error_test.go
+++ b/api/server/error_test.go
@@ -4,7 +4,7 @@ import (
 	"errors"
 	"testing"

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

 func TestDecodeError(t *testing.T) {
--- 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/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_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/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/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__",
@@ -51,10 +49,10 @@ go_library(
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/time: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/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",
@@ -143,7 +141,6 @@ go_test(
        "//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",
--- 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/forkchoice"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	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
@@ -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
@@ -556,10 +544,3 @@ func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
 	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/forkchoice"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 )

 // 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()
--- 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
@@ -28,8 +28,6 @@ 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")
--- 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.
@@ -150,9 +153,7 @@ 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[:])
@@ -161,7 +162,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			"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 +277,56 @@ 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 +335,51 @@ 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 +394,9 @@ 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/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -6,21 +6,21 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
-	"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/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/math"
-	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
+	"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/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/math"
+	ethpbv1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -276,7 +276,7 @@ func (s *Service) headBlock() (interfaces.ReadOnlySignedBeaconBlock, error) {
 // It does a full copy on head state for immutability.
 // This is a lock free version.
 func (s *Service) headState(ctx context.Context) state.BeaconState {
-	_, span := trace.StartSpan(ctx, "blockChain.headState")
+	ctx, span := trace.StartSpan(ctx, "blockChain.headState")
 	defer span.End()

 	return s.head.state.Copy()
@@ -286,7 +286,7 @@ func (s *Service) headState(ctx context.Context) state.BeaconState {
 // It does not perform a copy of the head state.
 // This is a lock free version.
 func (s *Service) headStateReadOnly(ctx context.Context) state.ReadOnlyBeaconState {
-	_, span := trace.StartSpan(ctx, "blockChain.headStateReadOnly")
+	ctx, span := trace.StartSpan(ctx, "blockChain.headStateReadOnly")
 	defer span.End()

 	return s.head.state
--- a/beacon-chain/blockchain/head_sync_committee_info.go
+++ b/beacon-chain/blockchain/head_sync_committee_info.go
@@ -5,17 +5,17 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/async"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/altair"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/async"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/altair"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

 // Initialize the state cache for sync committees.
--- a/beacon-chain/blockchain/head_sync_committee_info_test.go
+++ b/beacon-chain/blockchain/head_sync_committee_info_test.go
@@ -4,14 +4,14 @@ import (
 	"context"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
-	dbTest "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/signing"
+	dbTest "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

 func TestService_HeadSyncCommitteeIndices(t *testing.T) {
--- a/beacon-chain/blockchain/head_test.go
+++ b/beacon-chain/blockchain/head_test.go
@@ -7,20 +7,20 @@ import (
 	"testing"
 	"time"

-	mock "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/testing"
-	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/blstoexec"
-	"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"
-	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/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/v5/time/slots"
+	mock "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/testing"
+	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/blstoexec"
+	"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"
+	ethpbv1 "github.com/prysmaticlabs/prysm/v4/proto/eth/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"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -63,7 +63,7 @@ func TestSaveHead_Different(t *testing.T) {
 	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
-	state, blkRoot, err = prepareForkchoiceState(ctx, slots.PrevSlot(wsb.Block().Slot()), wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
+	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot()-1, wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))

@@ -238,7 +238,7 @@ func TestRetrieveHead_ReadOnly(t *testing.T) {
 	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
-	state, blkRoot, err := prepareForkchoiceState(ctx, slots.PrevSlot(wsb.Block().Slot()), wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
+	state, blkRoot, err := prepareForkchoiceState(ctx, wsb.Block().Slot()-1, wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))

--- a/beacon-chain/blockchain/init_sync_process_block.go
+++ b/beacon-chain/blockchain/init_sync_process_block.go
@@ -4,8 +4,8 @@ import (
 	"context"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 )

 // This saves a beacon block to the initial sync blocks cache. It rate limits how many blocks
--- a/beacon-chain/blockchain/init_sync_process_block_test.go
+++ b/beacon-chain/blockchain/init_sync_process_block_test.go
@@ -4,10 +4,10 @@ import (
 	"context"
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )

 func TestService_getBlock(t *testing.T) {
--- a/beacon-chain/blockchain/init_test.go
+++ b/beacon-chain/blockchain/init_test.go
@@ -1,7 +1,7 @@
 package blockchain

 import (
-	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
 )

 func init() {
--- a/beacon-chain/blockchain/kzg/BUILD.bazel
+++ b/beacon-chain/blockchain/kzg/BUILD.bazel
@@ -7,10 +7,11 @@ go_library(
        "validation.go",
    ],
    embedsrcs = ["trusted_setup.json"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/kzg",
+    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/kzg",
    visibility = ["//visibility:public"],
    deps = [
        "//consensus-types/blocks:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
@@ -24,7 +25,7 @@ go_test(
    ],
    embed = [":go_default_library"],
    deps = [
-        "//consensus-types/blocks:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "//testing/require:go_default_library",
        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
--- a/beacon-chain/blockchain/kzg/trusted_setup_test.go
+++ b/beacon-chain/blockchain/kzg/trusted_setup_test.go
@@ -3,7 +3,7 @@ package kzg
 import (
 	"testing"

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

 func TestStart(t *testing.T) {
--- a/beacon-chain/blockchain/kzg/validation.go
+++ b/beacon-chain/blockchain/kzg/validation.go
@@ -1,32 +1,42 @@
 package kzg

 import (
+	"fmt"
+
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )

-// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
-func Verify(sidecars ...blocks.ROBlob) error {
-	if len(sidecars) == 0 {
+// IsDataAvailable checks that
+// - all blobs in the block are available
+// - Expected KZG commitments match the number of blobs in the block
+// - That the number of proofs match the number of blobs
+// - That the proofs are verified against the KZG commitments
+func IsDataAvailable(commitments [][]byte, sidecars []*ethpb.DeprecatedBlobSidecar) error {
+	if len(commitments) != len(sidecars) {
+		return fmt.Errorf("could not check data availability, expected %d commitments, obtained %d",
+			len(commitments), len(sidecars))
+	}
+	if len(commitments) == 0 {
 		return nil
 	}
-	if len(sidecars) == 1 {
-		return kzgContext.VerifyBlobKZGProof(
-			bytesToBlob(sidecars[0].Blob),
-			bytesToCommitment(sidecars[0].KzgCommitment),
-			bytesToKZGProof(sidecars[0].KzgProof))
-	}
-	blobs := make([]GoKZG.Blob, len(sidecars))
-	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
-	proofs := make([]GoKZG.KZGProof, len(sidecars))
+	blobs := make([]GoKZG.Blob, len(commitments))
+	proofs := make([]GoKZG.KZGProof, len(commitments))
+	cmts := make([]GoKZG.KZGCommitment, len(commitments))
 	for i, sidecar := range sidecars {
 		blobs[i] = bytesToBlob(sidecar.Blob)
-		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
 		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
+		cmts[i] = bytesToCommitment(commitments[i])
 	}
 	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
 }

+// VerifyROBlobCommitment is a helper that massages the fields of an ROBlob into the types needed to call VerifyBlobKZGProof.
+func VerifyROBlobCommitment(sc blocks.ROBlob) error {
+	return kzgContext.VerifyBlobKZGProof(bytesToBlob(sc.Blob), bytesToCommitment(sc.KzgCommitment), bytesToKZGProof(sc.KzgProof))
+}
+
 func bytesToBlob(blob []byte) (ret GoKZG.Blob) {
 	copy(ret[:], blob)
 	return
--- a/beacon-chain/blockchain/kzg/validation_test.go
+++ b/beacon-chain/blockchain/kzg/validation_test.go
@@ -8,8 +8,8 @@ import (

 	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	"github.com/sirupsen/logrus"
 )

@@ -58,9 +58,10 @@ func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZG
 	return commitment, proof, err
 }

-func TestVerify(t *testing.T) {
-	sidecars := make([]blocks.ROBlob, 0)
-	require.NoError(t, Verify(sidecars...))
+func TestIsDataAvailable(t *testing.T) {
+	sidecars := make([]*ethpb.DeprecatedBlobSidecar, 0)
+	commitments := make([][]byte, 0)
+	require.NoError(t, IsDataAvailable(commitments, sidecars))
 }

 func TestBytesToAny(t *testing.T) {
--- a/beacon-chain/blockchain/lightclient.go
+++ b/beacon-chain/blockchain/lightclient.go
@@ -5,14 +5,14 @@ import (
 	"context"
 	"fmt"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-	"github.com/prysmaticlabs/prysm/v5/proto/migration"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpbv1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v4/proto/eth/v2"
+	"github.com/prysmaticlabs/prysm/v4/proto/migration"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

 const (
--- a/beacon-chain/blockchain/lightclient_test.go
+++ b/beacon-chain/blockchain/lightclient_test.go
@@ -4,16 +4,16 @@ import (
 	"context"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-	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/state"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v4/proto/eth/v2"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )

 type testlc struct {
--- a/beacon-chain/blockchain/log.go
+++ b/beacon-chain/blockchain/log.go
@@ -6,15 +6,15 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	prysmTime "github.com/prysmaticlabs/prysm/v5/time"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	consensus_types "github.com/prysmaticlabs/prysm/v4/consensus-types"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
+	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 )

@@ -73,7 +73,7 @@ func logStateTransitionData(b interfaces.ReadOnlyBeaconBlock) error {
 	return nil
 }

-func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte, justified, finalized *ethpb.Checkpoint, receivedTime time.Time, genesisTime uint64, daWaitedTime time.Duration) error {
+func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte, justified, finalized *ethpb.Checkpoint, receivedTime time.Time, genesisTime uint64) error {
 	startTime, err := slots.ToTime(genesisTime, block.Slot())
 	if err != nil {
 		return err
@@ -93,7 +93,7 @@ func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte
 			"parentRoot":                fmt.Sprintf("0x%s...", hex.EncodeToString(parentRoot[:])[:8]),
 			"version":                   version.String(block.Version()),
 			"sinceSlotStartTime":        prysmTime.Now().Sub(startTime),
-			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime) - daWaitedTime,
+			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime),
 			"deposits":                  len(block.Body().Deposits()),
 		}
 		log.WithFields(lf).Debug("Synced new block")
--- a/beacon-chain/blockchain/log_test.go
+++ b/beacon-chain/blockchain/log_test.go
@@ -3,11 +3,11 @@ package blockchain
 import (
 	"testing"

-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"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/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

--- a/beacon-chain/blockchain/metrics.go
+++ b/beacon-chain/blockchain/metrics.go
@@ -6,15 +6,15 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/altair"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epoch/precompute"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"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/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/altair"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/epoch/precompute"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"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"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 )

 var (
@@ -182,10 +182,6 @@ var (
 		Name: "chain_service_processing_milliseconds",
 		Help: "Total time to call a chain service in ReceiveBlock()",
 	})
-	dataAvailWaitedTime = promauto.NewSummary(prometheus.SummaryOpts{
-		Name: "da_waited_time_milliseconds",
-		Help: "Total time spent waiting for a data availability check in ReceiveBlock()",
-	})
 	processAttsElapsedTime = promauto.NewHistogram(
 		prometheus.HistogramOpts{
 			Name:    "process_attestations_milliseconds",
@@ -362,7 +358,6 @@ func reportEpochMetrics(ctx context.Context, postState, headState state.BeaconSt
 	for name, val := range refMap {
 		stateTrieReferences.WithLabelValues(name).Set(float64(val))
 	}
-	postState.RecordStateMetrics()

 	return nil
 }
--- a/beacon-chain/blockchain/metrics_test.go
+++ b/beacon-chain/blockchain/metrics_test.go
@@ -4,9 +4,9 @@ import (
 	"context"
 	"testing"

-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )

 func TestReportEpochMetrics_BadHeadState(t *testing.T) {
--- a/beacon-chain/blockchain/mock_test.go
+++ b/beacon-chain/blockchain/mock_test.go
@@ -3,10 +3,10 @@ package blockchain
 import (
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
+	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/startup"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state/stategen"
 )

 func testServiceOptsWithDB(t *testing.T) []Option {
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -1,22 +1,22 @@
 package blockchain

 import (
-	"github.com/prysmaticlabs/prysm/v5/async/event"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
-	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/blstoexec"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/slashings"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/voluntaryexits"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/async/event"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	statefeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db/filesystem"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/execution"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/attestations"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/blstoexec"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/slashings"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/voluntaryexits"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state/stategen"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )

 type Option func(s *Service) error
@@ -69,18 +69,10 @@ func WithDepositCache(c cache.DepositCache) Option {
 	}
 }

-// WithPayloadIDCache for payload ID cache.
-func WithPayloadIDCache(c *cache.PayloadIDCache) Option {
+// WithProposerIdsCache for proposer id cache.
+func WithProposerIdsCache(c *cache.ProposerPayloadIDsCache) Option {
 	return func(s *Service) error {
-		s.cfg.PayloadIDCache = c
-		return nil
-	}
-}
-
-// WithTrackedValidatorsCache for tracked validators cache.
-func WithTrackedValidatorsCache(c *cache.TrackedValidatorsCache) Option {
-	return func(s *Service) error {
-		s.cfg.TrackedValidatorsCache = c
+		s.cfg.ProposerSlotIndexCache = c
 		return nil
 	}
 }
@@ -173,7 +165,7 @@ func WithFinalizedStateAtStartUp(st state.BeaconState) Option {
 	}
 }

-// WithClockSynchronizer sets the ClockSetter/ClockWaiter values to be used by services that need to block until
+// WithClockSychronizer sets the ClockSetter/ClockWaiter values to be used by services that need to block until
 // the genesis timestamp is known (ClockWaiter) or which determine the genesis timestamp (ClockSetter).
 func WithClockSynchronizer(gs *startup.ClockSynchronizer) Option {
 	return func(s *Service) error {
@@ -198,10 +190,3 @@ func WithBlobStorage(b *filesystem.BlobStorage) Option {
 		return nil
 	}
 }
-
-func WithSyncChecker(checker Checker) Option {
-	return func(s *Service) error {
-		s.cfg.SyncChecker = checker
-		return nil
-	}
-}
--- a/beacon-chain/blockchain/pow_block.go
+++ b/beacon-chain/blockchain/pow_block.go
@@ -10,13 +10,13 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/holiman/uint256"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"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/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 )

--- a/beacon-chain/blockchain/pow_block_test.go
+++ b/beacon-chain/blockchain/pow_block_test.go
@@ -7,14 +7,14 @@ import (

 	gethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/holiman/uint256"
-	mocks "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/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/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	mocks "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/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/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
 )

 func Test_validTerminalPowBlock(t *testing.T) {
@@ -163,7 +163,7 @@ func Test_getBlkParentHashAndTD(t *testing.T) {
 	parentHash, totalDifficulty, err := service.getBlkParentHashAndTD(ctx, h[:])
 	require.NoError(t, err)
 	require.Equal(t, p, bytesutil.ToBytes32(parentHash))
-	require.Equal(t, td, totalDifficulty.Hex())
+	require.Equal(t, td, totalDifficulty.String())

 	_, _, err = service.getBlkParentHashAndTD(ctx, []byte{'c'})
 	require.ErrorContains(t, "could not get pow block: block not found", err)
--- a/beacon-chain/blockchain/process_attestation.go
+++ b/beacon-chain/blockchain/process_attestation.go
@@ -5,11 +5,11 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1/attestation"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"go.opencensus.io/trace"
 )

--- a/beacon-chain/blockchain/process_attestation_helpers.go
+++ b/beacon-chain/blockchain/process_attestation_helpers.go
@@ -6,16 +6,16 @@ import (
 	"strconv"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/async"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"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"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/async"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"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"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

 // getAttPreState retrieves the att pre state by either from the cache or the DB.
--- a/beacon-chain/blockchain/process_attestation_test.go
+++ b/beacon-chain/blockchain/process_attestation_test.go
@@ -6,16 +6,16 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	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/v5/time/slots"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	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"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

 func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
@@ -235,14 +235,14 @@ func TestStore_SaveCheckpointState(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, bytesutil.ToBytes32([]byte{'B'})))
 	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{Root: bytesutil.PadTo([]byte{'B'}, fieldparams.RootLength)}))

-	_, err = service.getAttPreState(ctx, cp2)
+	s2, err := service.getAttPreState(ctx, cp2)
 	require.ErrorContains(t, "epoch 2 root 0x4200000000000000000000000000000000000000000000000000000000000000: not a checkpoint in forkchoice", err)

 	st, root, err = prepareForkchoiceState(ctx, 33, [32]byte(cp2.Root), [32]byte(cp1.Root), [32]byte{'R'}, cp2, cp2)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))

-	s2, err := service.getAttPreState(ctx, cp2)
+	s2, err = service.getAttPreState(ctx, cp2)
 	require.NoError(t, err)

 	assert.Equal(t, 2*params.BeaconConfig().SlotsPerEpoch, s2.Slot(), "Unexpected state slot")
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -6,31 +6,30 @@ import (
 	"time"

 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	coreTime "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/filesystem"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"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/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/monitoring/tracing"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1/attestation"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
+	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
-
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	coreTime "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/das"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/features"
-	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/crypto/bls"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )

 // A custom slot deadline for processing state slots in our cache.
@@ -42,71 +41,106 @@ const depositDeadline = 20 * time.Second
 // This defines size of the upper bound for initial sync block cache.
 var initialSyncBlockCacheSize = uint64(2 * params.BeaconConfig().SlotsPerEpoch)

-// postBlockProcessConfig is a structure that contains the data needed to
-// process the beacon block after validating the state transition function
-type postBlockProcessConfig struct {
-	ctx            context.Context
-	signed         interfaces.ReadOnlySignedBeaconBlock
-	blockRoot      [32]byte
-	headRoot       [32]byte
-	postState      state.BeaconState
-	isValidPayload bool
-}
-
 // postBlockProcess is called when a gossip block is received. This function performs
 // several duties most importantly informing the engine if head was updated,
 // saving the new head information to the blockchain package and
 // handling attestations, slashings and similar included in the block.
-func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
-	ctx, span := trace.StartSpan(cfg.ctx, "blockChain.onBlock")
+func (s *Service) postBlockProcess(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, postState state.BeaconState, isValidPayload bool) error {
+	ctx, span := trace.StartSpan(ctx, "blockChain.onBlock")
 	defer span.End()
-	cfg.ctx = ctx
-	if err := consensusblocks.BeaconBlockIsNil(cfg.signed); err != nil {
+	if err := consensusblocks.BeaconBlockIsNil(signed); err != nil {
 		return invalidBlock{error: err}
 	}
 	startTime := time.Now()
-	fcuArgs := &fcuConfig{}
+	b := signed.Block()

-	if s.inRegularSync() {
-		defer s.handleSecondFCUCall(cfg, fcuArgs)
+	if err := s.cfg.ForkChoiceStore.InsertNode(ctx, postState, blockRoot); err != nil {
+		return errors.Wrapf(err, "could not insert block %d to fork choice store", signed.Block().Slot())
 	}
-	defer s.sendLightClientFeeds(cfg)
-	defer s.sendStateFeedOnBlock(cfg)
-	defer reportProcessingTime(startTime)
-	defer reportAttestationInclusion(cfg.signed.Block())
-
-	err := s.cfg.ForkChoiceStore.InsertNode(ctx, cfg.postState, cfg.blockRoot)
-	if err != nil {
-		return errors.Wrapf(err, "could not insert block %d to fork choice store", cfg.signed.Block().Slot())
-	}
-	if err := s.handleBlockAttestations(ctx, cfg.signed.Block(), cfg.postState); err != nil {
+	if err := s.handleBlockAttestations(ctx, signed.Block(), postState); err != nil {
 		return errors.Wrap(err, "could not handle block's attestations")
 	}

-	s.InsertSlashingsToForkChoiceStore(ctx, cfg.signed.Block().Body().AttesterSlashings())
-	if cfg.isValidPayload {
-		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, cfg.blockRoot); err != nil {
+	s.InsertSlashingsToForkChoiceStore(ctx, signed.Block().Body().AttesterSlashings())
+	if isValidPayload {
+		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, blockRoot); err != nil {
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
+
 	start := time.Now()
-	cfg.headRoot, err = s.cfg.ForkChoiceStore.Head(ctx)
+	headRoot, err := s.cfg.ForkChoiceStore.Head(ctx)
 	if err != nil {
 		log.WithError(err).Warn("Could not update head")
 	}
+	if blockRoot != headRoot {
+		receivedWeight, err := s.cfg.ForkChoiceStore.Weight(blockRoot)
+		if err != nil {
+			log.WithField("root", fmt.Sprintf("%#x", blockRoot)).Warn("could not determine node weight")
+		}
+		headWeight, err := s.cfg.ForkChoiceStore.Weight(headRoot)
+		if err != nil {
+			log.WithField("root", fmt.Sprintf("%#x", headRoot)).Warn("could not determine node weight")
+		}
+		log.WithFields(logrus.Fields{
+			"receivedRoot":   fmt.Sprintf("%#x", blockRoot),
+			"receivedWeight": receivedWeight,
+			"headRoot":       fmt.Sprintf("%#x", headRoot),
+			"headWeight":     headWeight,
+		}).Debug("Head block is not the received block")
+	}
 	newBlockHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
-	if cfg.headRoot != cfg.blockRoot {
-		s.logNonCanonicalBlockReceived(cfg.blockRoot, cfg.headRoot)
-		return nil
-	}
-	if err := s.getFCUArgs(cfg, fcuArgs); err != nil {
-		log.WithError(err).Error("Could not get forkchoice update argument")
-		return nil
-	}
-	if err := s.sendFCU(cfg, fcuArgs); err != nil {
-		return errors.Wrap(err, "could not send FCU to engine")
+
+	// verify conditions for FCU, notifies FCU, and saves the new head.
+	// This function also prunes attestations, other similar operations happen in prunePostBlockOperationPools.
+	if _, err := s.forkchoiceUpdateWithExecution(ctx, headRoot, s.CurrentSlot()+1); err != nil {
+		return err
 	}

+	optimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(blockRoot)
+	if err != nil {
+		log.WithError(err).Debug("Could not check if block is optimistic")
+		optimistic = true
+	}
+
+	// Send notification of the processed block to the state feed.
+	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+		Type: statefeed.BlockProcessed,
+		Data: &statefeed.BlockProcessedData{
+			Slot:        signed.Block().Slot(),
+			BlockRoot:   blockRoot,
+			SignedBlock: signed,
+			Verified:    true,
+			Optimistic:  optimistic,
+		},
+	})
+
+	defer reportAttestationInclusion(b)
+	if headRoot == blockRoot {
+		// Updating next slot state cache can happen in the background
+		// except in the epoch boundary in which case we lock to handle
+		// the shuffling and proposer caches updates.
+		// We handle these caches only on canonical
+		// blocks, otherwise this will be handled by lateBlockTasks
+		slot := postState.Slot()
+		if slots.IsEpochEnd(slot) {
+			if err := transition.UpdateNextSlotCache(ctx, blockRoot[:], postState); err != nil {
+				return errors.Wrap(err, "could not update next slot state cache")
+			}
+			if err := s.handleEpochBoundary(ctx, slot, postState, blockRoot[:]); err != nil {
+				return errors.Wrap(err, "could not handle epoch boundary")
+			}
+		} else {
+			go func() {
+				slotCtx, cancel := context.WithTimeout(context.Background(), slotDeadline)
+				defer cancel()
+				if err := transition.UpdateNextSlotCache(slotCtx, blockRoot[:], postState); err != nil {
+					log.WithError(err).Error("could not update next slot state cache")
+				}
+			}()
+		}
+	}
+	onBlockProcessingTime.Observe(float64(time.Since(startTime).Milliseconds()))
 	return nil
 }

@@ -128,7 +162,7 @@ func getStateVersionAndPayload(st state.BeaconState) (int, interfaces.ExecutionD
 	return preStateVersion, preStateHeader, nil
 }

-func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlock, avs das.AvailabilityStore) error {
+func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlock) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.onBlockBatch")
 	defer span.End()

@@ -231,8 +265,8 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 				return err
 			}
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
-			return errors.Wrapf(err, "could not validate blob data availability at slot %d", b.Block().Slot())
+		if err := s.databaseDACheck(ctx, b); err != nil {
+			return errors.Wrap(err, "could not validate blob data availability")
 		}
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
 			JustifiedCheckpoint: jCheckpoints[i],
@@ -288,10 +322,10 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
-	arg := &fcuConfig{
+	arg := &notifyForkchoiceUpdateArg{
 		headState: preState,
 		headRoot:  lastBR,
-		headBlock: lastB,
+		headBlock: lastB.Block(),
 	}
 	if _, err := s.notifyForkchoiceUpdate(ctx, arg); err != nil {
 		return err
@@ -299,6 +333,37 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }

+func commitmentsToCheck(b consensusblocks.ROBlock, current primitives.Slot) [][]byte {
+	if b.Version() < version.Deneb {
+		return nil
+	}
+	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	if !params.WithinDAPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(current)) {
+		return nil
+	}
+	kzgCommitments, err := b.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil
+	}
+	return kzgCommitments
+}
+
+func (s *Service) databaseDACheck(ctx context.Context, b consensusblocks.ROBlock) error {
+	commitments := commitmentsToCheck(b, s.CurrentSlot())
+	if len(commitments) == 0 {
+		return nil
+	}
+	missing, err := missingIndices(s.blobStorage, b.Root(), commitments)
+	if err != nil {
+		return err
+	}
+	if len(missing) == 0 {
+		return nil
+	}
+	// TODO: don't worry that this error isn't informative, it will be superceded by a detailed sidecar cache error.
+	return errors.New("not all kzg commitments are available")
+}
+
 func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.BeaconState) error {
 	e := coreTime.CurrentEpoch(st)
 	if err := helpers.UpdateCommitteeCache(ctx, st, e); err != nil {
@@ -307,36 +372,19 @@ func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.Beacon
 	if err := helpers.UpdateProposerIndicesInCache(ctx, st, e); err != nil {
 		return errors.Wrap(err, "could not update proposer index cache")
 	}
-	go func(ep primitives.Epoch) {
+	go func() {
 		// Use a custom deadline here, since this method runs asynchronously.
 		// We ignore the parent method's context and instead create a new one
 		// with a custom deadline, therefore using the background context instead.
 		slotCtx, cancel := context.WithTimeout(context.Background(), slotDeadline)
 		defer cancel()
-		if err := helpers.UpdateCommitteeCache(slotCtx, st, ep+1); err != nil {
+		if err := helpers.UpdateCommitteeCache(slotCtx, st, e+1); err != nil {
 			log.WithError(err).Warn("Could not update committee cache")
 		}
-	}(e)
-	// The latest block header is from the previous epoch
-	r, err := st.LatestBlockHeader().HashTreeRoot()
-	if err != nil {
-		log.WithError(err).Error("could not update proposer index state-root map")
-		return nil
-	}
-	// The proposer indices cache takes the target root for the previous
-	// epoch as key
-	if e > 0 {
-		e = e - 1
-	}
-	target, err := s.cfg.ForkChoiceStore.TargetRootForEpoch(r, e)
-	if err != nil {
-		log.WithError(err).Error("could not update proposer index state-root map")
-		return nil
-	}
-	err = helpers.UpdateCachedCheckpointToStateRoot(st, &forkchoicetypes.Checkpoint{Epoch: e, Root: target})
-	if err != nil {
-		log.WithError(err).Error("could not update proposer index state-root map")
-	}
+		if err := helpers.UpdateProposerIndicesInCache(slotCtx, st, e+1); err != nil {
+			log.WithError(err).Warn("Failed to cache next epoch proposers")
+		}
+	}()
 	return nil
 }

@@ -585,15 +633,10 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	if s.CurrentSlot() == s.HeadSlot() {
 		return
 	}
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	// return early if we are in init sync
-	if !s.inRegularSync() {
-		return
-	}
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.MissedSlot,
 	})
+
 	s.headLock.RLock()
 	headRoot := s.headRoot()
 	headState := s.headState(ctx)
@@ -611,16 +654,10 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	if err := s.handleEpochBoundary(ctx, currentSlot, headState, headRoot[:]); err != nil {
 		log.WithError(err).Error("lateBlockTasks: could not update epoch boundary caches")
 	}
-	// return early if we already started building a block for the current
-	// head root
-	_, has := s.cfg.PayloadIDCache.PayloadID(s.CurrentSlot()+1, headRoot)
-	if has {
-		return
-	}
-
-	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
-	// return early if we are not proposing next slot
-	if attribute.IsEmpty() {
+	// Head root should be empty when retrieving proposer index for the next slot.
+	_, id, has := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(s.CurrentSlot()+1, [32]byte{} /* head root */)
+	// There exists proposer for next slot, but we haven't called fcu w/ payload attribute yet.
+	if (!has && !features.Get().PrepareAllPayloads) || id != [8]byte{} {
 		return
 	}

@@ -632,14 +669,13 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 		return
 	}
 	s.headLock.RUnlock()
-
-	fcuArgs := &fcuConfig{
-		headState:  headState,
-		headRoot:   headRoot,
-		headBlock:  headBlock,
-		attributes: attribute,
-	}
-	_, err = s.notifyForkchoiceUpdate(ctx, fcuArgs)
+	s.cfg.ForkChoiceStore.RLock()
+	_, err = s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
+		headState: headState,
+		headRoot:  headRoot,
+		headBlock: headBlock.Block(),
+	})
+	s.cfg.ForkChoiceStore.RUnlock()
 	if err != nil {
 		log.WithError(err).Debug("could not perform late block tasks: failed to update forkchoice with engine")
 	}
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .0.0
 .4.0