wip

Gazelle
Update spec test to v1.4.0-beta.7-hotfix
2026-01-09 21:38:05 -05:00 · 2024-02-16 14:36:10 -06:00 · 2024-02-15 19:00:43 -08:00 · 2024-02-15 18:18:08 -08:00 · 2024-02-15 11:57:45 -08:00 · 2024-02-09 14:40:57 -03:00
1000 changed files with 44815 additions and 44481 deletions
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-6.3.2
+7.0.0
--- a/.buildkite-bazelrc
+++ b/.buildkite-bazelrc
@@ -9,8 +9,8 @@
 #build:remote-cache --strategy=Genrule=standalone

 # Prysm specific remote-cache properties.
-#build:remote-cache --disk_cache=
-build:remote-cache --remote_download_toplevel
+build:remote-cache --remote_download_minimal
+build:remote-cache --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
@@ -29,7 +29,10 @@ build --experimental_use_hermetic_linux_sandbox
 # Import workspace options.
 import %workspace%/.bazelrc

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

--- a/.github/actions/gomodtidy/Dockerfile
+++ b/.github/actions/gomodtidy/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:alpine
+FROM golang:1.21-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: '1.20'
+          go-version: '1.21.5'
      - id: list
        uses: shogo82148/actions-go-fuzz/list@v0
        with:
@@ -36,7 +36,7 @@ jobs:
      - uses: actions/checkout@v3
      - uses: actions/setup-go@v4
        with:
-          go-version: '1.20'
+          go-version: '1.21.5'
      - uses: shogo82148/actions-go-fuzz/run@v0
        with:
          packages: ${{ matrix.package }}
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -5,6 +5,8 @@ on:
    branches: [ master ]
  pull_request:
    branches: [ '*' ]
+  merge_group:
+    types: [checks_requested]

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

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

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

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

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

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

 linters:
-  disable-all: true
-  enable:
-    - gofmt
-    - goimports
-    - unused
-    - errcheck
-    - gosimple
-    - gocognit
-    - dupword
-    - nilerr
-    - whitespace
-    - misspell
+  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

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

 prefix = "github.com/prysmaticlabs/prysm"

@@ -82,38 +83,117 @@ workspace_binary(
    cmd = "@com_github_golang_lint//golint",
 )

+STATICCHECK_ANALYZERS = [
+    # Enabled static checks. See https://staticcheck.dev/docs/checks/
+    # Please. keep this list sorted. Don't be a bad person by inserting stuff randomly.
+    "sa1000",
+    "sa1001",
+    "sa1002",
+    "sa1003",
+    "sa1004",
+    "sa1005",
+    "sa1006",
+    "sa1007",
+    "sa1008",
+    "sa1010",
+    "sa1011",
+    "sa1012",
+    "sa1013",
+    "sa1014",
+    "sa1015",
+    "sa1016",
+    "sa1017",
+    "sa1018",
+    # "sa1019", # TODO: Fix all uses of deprecated things.
+    "sa1020",
+    "sa1021",
+    "sa1023",
+    "sa1024",
+    "sa1025",
+    "sa1026",
+    "sa1027",
+    "sa1028",
+    "sa1029",
+    "sa1030",
+    "sa2000",
+    "sa2001",
+    "sa2002",
+    "sa2003",
+    "sa3000",
+    "sa3001",
+    "sa4000",
+    "sa4001",
+    "sa4003",
+    "sa4004",
+    "sa4005",
+    "sa4006",
+    "sa4008",
+    "sa4009",
+    "sa4010",
+    "sa4011",
+    "sa4012",
+    "sa4013",
+    "sa4014",
+    "sa4015",
+    "sa4016",
+    "sa4017",
+    "sa4018",
+    "sa4019",
+    "sa4020",
+    "sa4021",
+    "sa4022",
+    "sa4023",
+    "sa4024",
+    "sa4025",
+    "sa4026",
+    "sa4027",
+    "sa4028",
+    "sa4029",
+    "sa4030",
+    "sa4031",
+    "sa4032",
+    "sa5000",
+    "sa5001",
+    "sa5002",
+    "sa5003",
+    "sa5004",
+    "sa5005",
+    "sa5007",
+    "sa5008",
+    "sa5009",
+    "sa5010",
+    "sa5011",
+    "sa5012",
+    "sa6000",
+    "sa6001",
+    "sa6002",
+    "sa6003",
+    "sa6005",
+    "sa6006",
+    "sa9001",
+    "sa9002",
+    #"sa9003", # Doesn't build. See https://github.com/dominikh/go-tools/pull/1483
+    "sa9004",
+    "sa9005",
+    "sa9006",
+    "sa9007",
+    "sa9008",
+]
+
+nogo_config_exclude(
+    name = "nogo_config_with_excludes",
+    checks = [sa.upper() for sa in STATICCHECK_ANALYZERS],
+    exclude_files = [
+        "external/.*",
+    ],
+    input = "nogo_config.json",
+)
+
 nogo(
    name = "nogo",
-    config = "nogo_config.json",
+    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",
@@ -129,6 +209,53 @@ 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": [],
@@ -136,7 +263,7 @@ nogo(
            "@org_golang_x_tools//go/analysis/passes/composite:go_default_library",
            "@org_golang_x_tools//go/analysis/passes/lostcancel:go_default_library",
        ],
-    }),
+    }) + ["@co_honnef_go_tools//staticcheck/%s:go_default_library" % c for c in STATICCHECK_ANALYZERS],
 )

 config_setting(
--- 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 `gazelle update-repos -from_file=go.mod` to update the bazel managed dependencies.
+1. Run `bazel run //:gazelle -- update-repos -from_file=go.mod` to update the bazel managed dependencies.

 Example:

--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -0,0 +1,6 @@
+###############################################################################
+# Bazel now uses Bzlmod by default to manage external dependencies.
+# Please consider migrating your external dependencies from WORKSPACE to MODULE.bazel.
+#
+# For more details, please check https://github.com/bazelbuild/bazel/issues/18958
+###############################################################################
--- a/MODULE.bazel.lock
+++ b/MODULE.bazel.lock
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
 [![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysmaticlabs)
 [![GitPOAP Badge](https://public-api.gitpoap.io/v1/repo/prysmaticlabs/prysm/badge)](https://www.gitpoap.io/gh/prysmaticlabs/prysm)

-This is the core repository for Prysm, a [Golang](https://golang.org/) implementation of the [Ethereum Consensus](https://ethereum.org/en/eth2/) specification, developed by [Prysmatic Labs](https://prysmaticlabs.com). See the [Changelog](https://github.com/prysmaticlabs/prysm/releases) for details of the latest releases and upcoming breaking changes.
+This is the core repository for Prysm, a [Golang](https://golang.org/) implementation of the [Ethereum Consensus](https://ethereum.org/en/developers/docs/consensus-mechanisms/#proof-of-stake) [specification](https://github.com/ethereum/consensus-specs), developed by [Offchain Labs](https://www.offchainlabs.com). See the [Changelog](https://github.com/prysmaticlabs/prysm/releases) for details of the latest releases and upcoming breaking changes.

 ### Getting Started

--- a/165
+++ b/165
@@ -96,11 +96,29 @@ http_archive(
 )

 http_archive(
-    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"],
+    name = "rules_distroless",
+    sha256 = "e64f06e452cd153aeab81f752ccf4642955b3af319e64f7bc7a7c9252f76b10e",
+    strip_prefix = "rules_distroless-f5e678217b57ce3ad2f1c0204bd4e9d416255773",
+    url = "https://github.com/GoogleContainerTools/rules_distroless/archive/f5e678217b57ce3ad2f1c0204bd4e9d416255773.tar.gz",
 )

+load("@rules_distroless//distroless:dependencies.bzl", "rules_distroless_dependencies")
+
+rules_distroless_dependencies()
+
+http_archive(
+    name = "distroless",
+    integrity = "sha256-Cf00kUp1NyXA3LzbdyYy4Kda27wbkB8+A9MliTxq4jE=",
+    strip_prefix = "distroless-9dc924b9fe812eec2fa0061824dcad39eb09d0d6",
+    url = "https://github.com/GoogleContainerTools/distroless/archive/9dc924b9fe812eec2fa0061824dcad39eb09d0d6.tar.gz",  # 2024-01-24
+)
+
+load("@aspect_bazel_lib//lib:repositories.bzl", "aspect_bazel_lib_dependencies", "aspect_bazel_lib_register_toolchains")
+
+aspect_bazel_lib_dependencies()
+
+aspect_bazel_lib_register_toolchains()
+
 http_archive(
    name = "rules_oci",
    sha256 = "c71c25ed333a4909d2dd77e0b16c39e9912525a98c7fa85144282be8d04ef54c",
@@ -126,13 +144,17 @@ http_archive(
        # Expose internals of go_test for custom build transitions.
        "//third_party:io_bazel_rules_go_test.patch",
    ],
-    sha256 = "91585017debb61982f7054c9688857a2ad1fd823fc3f9cb05048b0025c47d023",
+    sha256 = "d6ab6b57e48c09523e93050f13698f708428cfd5e619252e369d377af6597707",
    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.42.0/rules_go-v0.42.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.42.0/rules_go-v0.42.0.zip",
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.43.0/rules_go-v0.43.0.zip",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.43.0/rules_go-v0.43.0.zip",
    ],
 )

+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(
@@ -148,67 +170,16 @@ 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 = "sha256:9b8e0854865dcaf49470b4ec305df45957020fbcf17b71eeb50ffd3bc5bf885d",  # 2023-05-17
+    digest = "sha256:b82f113425c5b5c714151aaacd8039bc141821cdcd3c65202d42bdf9c43ae60b",  # 2023-12-12
    image = "gcr.io/distroless/cc-debian11",
    platforms = [
        "linux/amd64",
-        "linux/arm64",
+        "linux/arm64/v8",
    ],
    reproducible = True,
 )
@@ -222,7 +193,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()

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

@@ -244,8 +215,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "91434d5fd5e1c6eb7b0174fed2afe25e09bddf00e1e4c431db931b2cee4e7773",
-    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/b8413ca42dc92308019d0d4db52c87e9e125c4e9.tar.gz",
+    sha256 = "516d551cfb3e50e4ac2f42db0992f4ceb573a7cb1616d727a725c8161485329f",
+    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/refs/tags/v5.3.0.tar.gz",
 )

 http_archive(
@@ -263,7 +234,9 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.4.0-beta.3"
+consensus_spec_version = "v1.4.0-beta.7"
+
+consensus_spec_test_version = "v1.4.0-beta.7-hotfix"

 bls_test_version = "v0.1.1"

@@ -279,8 +252,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "67ae5b8fc368853da23d4297e480a4b7f4722fb970d1c7e2b6a5b7faef9cb907",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
+    sha256 = "c282c0f86f23f3d2e0f71f5975769a4077e62a7e3c7382a16bd26a7e589811a0",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_test_version,
 )

 http_archive(
@@ -295,8 +268,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "82474f29fff4abd09fb1e71bafa98827e2573cf0ad02cf119610961831dc3bb5",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
+    sha256 = "4649c35aa3b8eb0cfdc81bee7c05649f90ef36bede5b0513e1f2e8baf37d6033",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_test_version,
 )

 http_archive(
@@ -311,8 +284,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "60e4b6eb6c341daab7ee5614a8e3f28567247c504c593b951bfe919622c8ef8f",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
+    sha256 = "c5a03f724f757456ffaabd2a899992a71d2baf45ee4db65ca3518f2b7ee928c8",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_test_version,
 )

 http_archive(
@@ -326,7 +299,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "fdab9756c93a250219ff6a10d5a9faee1e2e6878a14508410409e307362c6991",
+    sha256 = "049c29267310e6b88280f4f834a75866c2f5b9036fa97acb9d9c6db8f64d9118",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -357,9 +330,25 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "2701e1e1a3ec10c673fe7dbdbbe6f02c8ae8c922aebbf6e720d8c72d5458aafe",
-    strip_prefix = "eth2-networks-7b4897888cebef23801540236f73123e21774954",
-    url = "https://github.com/eth-clients/eth2-networks/archive/7b4897888cebef23801540236f73123e21774954.tar.gz",
+    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",
 )

 http_archive(
@@ -373,17 +362,17 @@ filegroup(
    visibility = ["//visibility:public"],
 )
 """,
-    sha256 = "9f66d8d5644982d3d0d2e3d2b9ebe77a5f96638a5d7fcd715599c32818195cb3",
-    strip_prefix = "holesky-ea39b9006210848e13f28d92e12a30548cecd41d",
-    url = "https://github.com/eth-clients/holesky/archive/ea39b9006210848e13f28d92e12a30548cecd41d.tar.gz",  # 2023-09-21
+    sha256 = "5f4be6fd088683ea9db45c863b9c5a1884422449e5b59fd2d561d3ba0f73ffd9",
+    strip_prefix = "holesky-9d9aabf2d4de51334ee5fed6c79a4d55097d1a43",
+    url = "https://github.com/eth-clients/holesky/archive/9d9aabf2d4de51334ee5fed6c79a4d55097d1a43.tar.gz",  # 2024-01-22
 )

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

@@ -417,24 +406,6 @@ load("@prysm//testing/endtoend:deps.bzl", "e2e_deps")

 e2e_deps()

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

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

 go_library(
    name = "go_default_library",
-    srcs = ["headers.go"],
+    srcs = [
+        "constants.go",
+        "headers.go",
+    ],
    importpath = "github.com/prysmaticlabs/prysm/v4/api",
    visibility = ["//visibility:public"],
 )
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -11,11 +11,9 @@ go_library(
    visibility = ["//visibility:public"],
    deps = [
        "//api/client:go_default_library",
+        "//api/server:go_default_library",
+        "//api/server/structs:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/rpc/apimiddleware:go_default_library",
-        "//beacon-chain/rpc/eth/beacon:go_default_library",
-        "//beacon-chain/rpc/eth/config:go_default_library",
-        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -16,10 +16,8 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/api/client"
-	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/apimiddleware"
-	"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"
+	"github.com/prysmaticlabs/prysm/v4/api/server"
+	"github.com/prysmaticlabs/prysm/v4/api/server/structs"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v4/network/forks"
@@ -31,7 +29,7 @@ const (
 	getSignedBlockPath       = "/eth/v2/beacon/blocks"
 	getBlockRootPath         = "/eth/v1/beacon/blocks/{{.Id}}/root"
 	getForkForStatePath      = "/eth/v1/beacon/states/{{.Id}}/fork"
-	getWeakSubjectivityPath  = "/eth/v1/beacon/weak_subjectivity"
+	getWeakSubjectivityPath  = "/prysm/v1/beacon/weak_subjectivity"
 	getForkSchedulePath      = "/eth/v1/config/fork_schedule"
 	getConfigSpecPath        = "/eth/v1/config/spec"
 	getStatePath             = "/eth/v2/debug/beacon/states"
@@ -149,8 +147,8 @@ 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 := &shared.Fork{}
-	dataWrapper := &struct{ Data *shared.Fork }{Data: fr}
+	fr := &structs.Fork{}
+	dataWrapper := &struct{ Data *structs.Fork }{Data: fr}
 	err = json.Unmarshal(body, dataWrapper)
 	if err != nil {
 		return nil, errors.Wrap(err, "error decoding json response in GetFork")
@@ -178,12 +176,12 @@ 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) (*config.GetSpecResponse, error) {
+func (c *Client) GetConfigSpec(ctx context.Context) (*structs.GetSpecResponse, error) {
 	body, err := c.Get(ctx, getConfigSpecPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting configSpecPath")
 	}
-	fsr := &config.GetSpecResponse{}
+	fsr := &structs.GetSpecResponse{}
 	err = json.Unmarshal(body, fsr)
 	if err != nil {
 		return nil, err
@@ -258,16 +256,16 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 	if err != nil {
 		return nil, err
 	}
-	v := &apimiddleware.WeakSubjectivityResponse{}
+	v := &structs.GetWeakSubjectivityResponse{}
 	err = json.Unmarshal(body, v)
 	if err != nil {
 		return nil, err
 	}
-	epoch, err := strconv.ParseUint(v.Data.Checkpoint.Epoch, 10, 64)
+	epoch, err := strconv.ParseUint(v.Data.WsCheckpoint.Epoch, 10, 64)
 	if err != nil {
 		return nil, err
 	}
-	blockRoot, err := hexutil.Decode(v.Data.Checkpoint.Root)
+	blockRoot, err := hexutil.Decode(v.Data.WsCheckpoint.Root)
 	if err != nil {
 		return nil, err
 	}
@@ -284,7 +282,7 @@ 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 []*shared.SignedBLSToExecutionChange) error {
+func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*structs.SignedBLSToExecutionChange) error {
 	u := c.BaseURL().ResolveReference(&url.URL{Path: changeBLStoExecutionPath})
 	body, err := json.Marshal(request)
 	if err != nil {
@@ -305,7 +303,7 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*shar
 	if resp.StatusCode != http.StatusOK {
 		decoder := json.NewDecoder(resp.Body)
 		decoder.DisallowUnknownFields()
-		errorJson := &apimiddleware.IndexedVerificationFailureErrorJson{}
+		errorJson := &server.IndexedVerificationFailureError{}
 		if err := decoder.Decode(errorJson); err != nil {
 			return errors.Wrapf(err, "failed to decode error JSON for %s", resp.Request.URL)
 		}
@@ -323,12 +321,12 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*shar

 // 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) (*beacon.BLSToExecutionChangesPoolResponse, error) {
+func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToExecutionChangesPoolResponse, error) {
 	body, err := c.Get(ctx, changeBLStoExecutionPath)
 	if err != nil {
 		return nil, err
 	}
-	poolResponse := &beacon.BLSToExecutionChangesPoolResponse{}
+	poolResponse := &structs.BLSToExecutionChangesPoolResponse{}
 	err = json.Unmarshal(body, poolResponse)
 	if err != nil {
 		return nil, err
@@ -337,7 +335,7 @@ func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*beacon.BLSToExe
 }

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

 func (fsr *forkScheduleResponse) OrderedForkSchedule() (forks.OrderedSchedule, error) {
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -11,7 +11,7 @@ go_library(
    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/builder",
    visibility = ["//visibility:public"],
    deps = [
-        "//beacon-chain/rpc/eth/shared:go_default_library",
+        "//api/server/structs:go_default_library",
        "//config/fieldparams:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
@@ -20,8 +20,6 @@ go_library(
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//monitoring/tracing:go_default_library",
-        "//network:go_default_library",
-        "//network/authorization:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
@@ -42,7 +40,7 @@ go_test(
    data = glob(["testdata/**"]),
    embed = [":go_default_library"],
    deps = [
-        "//beacon-chain/rpc/eth/shared:go_default_library",
+        "//api/server/structs: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
@@ -6,7 +6,6 @@ import (
 	consensus_types "github.com/prysmaticlabs/prysm/v4/consensus-types"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
-	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 )
@@ -22,7 +21,7 @@ type SignedBid interface {
 // Bid is an interface describing the method set of a builder bid.
 type Bid interface {
 	Header() (interfaces.ExecutionData, error)
-	BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error)
+	BlobKzgCommitments() ([][]byte, error)
 	Value() []byte
 	Pubkey() []byte
 	Version() int
@@ -115,9 +114,9 @@ func (b builderBid) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeader(b.p.Header)
 }

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

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

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

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

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

 type signedBuilderBidDeneb struct {
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"math/big"
 	"net"
 	"net/http"
 	"net/url"
@@ -13,14 +14,12 @@ import (
 	"text/template"

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

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

 func urlForHost(h string) (*url.URL, error) {
 	// try to parse as url (being permissive)
-	u, err := url.Parse(h)
-	if err == nil && u.Host != "" {
+	if u, err := url.Parse(h); err == nil && u.Host != "" {
 		return u, nil
 	}
 	// try to parse as host:port
@@ -140,7 +137,7 @@ func (c *Client) NodeURL() string {

 type reqOption func(*http.Request)

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

 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
-func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	if !sb.IsBlinded() {
 		return nil, nil, errNotBlinded
 	}
@@ -301,7 +294,7 @@ 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 := shared.SignedBlindedBeaconBlockBellatrixFromConsensus(&ethpb.SignedBlindedBeaconBlockBellatrix{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := structs.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")
 		}
@@ -338,7 +331,7 @@ 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 := shared.SignedBlindedBeaconBlockCapellaFromConsensus(&ethpb.SignedBlindedBeaconBlockCapella{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := structs.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")
 		}
@@ -365,7 +358,7 @@ 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, 0)
+		payload, err := blocks.WrappedExecutionPayloadCapella(p, big.NewInt(0))
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
 		}
@@ -375,9 +368,9 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := shared.SignedBlindedBeaconBlockContentsDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockAndBlobsDeneb{SignedBlindedBlock: psb, SignedBlindedBlobSidecars: blobs})
+		b, err := structs.SignedBlindedBeaconBlockDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockDeneb{Message: psb.Message, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
 		if err != nil {
-			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockContentsDeneb to json marshalable type")
+			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockDeneb to json marshalable type")
 		}
 		body, err := json.Marshal(b)
 		if err != nil {
@@ -402,7 +395,7 @@ 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, 0)
+		payload, err := blocks.WrappedExecutionPayloadDeneb(p, big.NewInt(0))
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
 		}
@@ -431,38 +424,29 @@ 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 204:
+	case http.StatusNoContent:
 		log.WithError(ErrNoContent).Debug(msg)
 		return ErrNoContent
-	case 400:
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
+	case http.StatusBadRequest:
 		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 404:
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
+	case http.StatusNotFound:
 		log.WithError(ErrNotFound).Debug(msg)
-		return errors.Wrap(ErrNotFound, errMessage.Message)
-	case 500:
 		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)
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		return errors.Wrap(ErrNotOK, errMessage.Message)
 	default:
 		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, fmt.Sprintf("unsupported error code: %d", response.StatusCode))
 	}
 }
-
-func covertEndPoint(ep string) network.Endpoint {
-	return network.Endpoint{
-		Url: ep,
-		Auth: network.AuthorizationData{ // Auth is not used for builder.
-			Method: authorization.None,
-			Value:  "",
-		}}
-}
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -12,10 +12,8 @@ import (
 	"strconv"
 	"testing"

-	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
-	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/api/server/structs"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	types "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
@@ -270,28 +268,20 @@ func TestClient_GetHeader(t *testing.T) {
 		bidValue := bytesutil.ReverseByteOrder(bid.Value())
 		require.DeepEqual(t, bidValue, value.Bytes())
 		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
-		bundle, err := bid.BlindedBlobsBundle()
+		kcgCommitments, err := bid.BlobKzgCommitments()
 		require.NoError(t, err)
-		require.Equal(t, len(bundle.BlobRoots) <= fieldparams.MaxBlobsPerBlock && len(bundle.BlobRoots) > 0, true)
-		for i := range bundle.BlobRoots {
-			require.Equal(t, len(bundle.BlobRoots[i]) == fieldparams.RootLength, true)
-		}
-		require.Equal(t, len(bundle.KzgCommitments) > 0, true)
-		for i := range bundle.KzgCommitments {
-			require.Equal(t, len(bundle.KzgCommitments[i]) == 48, true)
-		}
-		require.Equal(t, len(bundle.Proofs) > 0, true)
-		for i := range bundle.Proofs {
-			require.Equal(t, len(bundle.Proofs[i]) == 48, true)
+		require.Equal(t, len(kcgCommitments) > 0, true)
+		for i := range kcgCommitments {
+			require.Equal(t, len(kcgCommitments[i]) == 48, true)
 		}
 	})
-	t.Run("deneb, no bundle", func(t *testing.T) {
+	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(testExampleHeaderResponseDenebNoBundle)),
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebTooManyBlobs)),
 					Request:    r.Clone(ctx),
 				}, nil
 			}),
@@ -300,27 +290,9 @@ func TestClient_GetHeader(t *testing.T) {
 			hc:      hc,
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}
-		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
-		require.NoError(t, err)
-		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-		bid, err := h.Message()
-		require.NoError(t, err)
-		bidHeader, err := bid.Header()
-		require.NoError(t, err)
-		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
-		require.NoError(t, err)
-		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
-		value, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
-		require.NoError(t, err)
-		require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", bid.Value()))
-		bidValue := bytesutil.ReverseByteOrder(bid.Value())
-		require.DeepEqual(t, bidValue, value.Bytes())
-		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
-		bundle, err := bid.BlindedBlobsBundle()
-		require.NoError(t, err)
-		require.Equal(t, (*v1.BlindedBlobsBundle)(nil), bundle)
+		_, 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) {
@@ -362,7 +334,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb, nil)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb)
 		require.NoError(t, err)
 		require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash()))
 		bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
@@ -388,7 +360,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockCapella(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbb, nil)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbb)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -399,18 +371,17 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
 	t.Run("deneb", func(t *testing.T) {
-
-		test := testSignedBlindedBeaconBlockAndBlobsDeneb(t)
+		test := testSignedBlindedBeaconBlockDeneb(t)
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
 				require.Equal(t, "deneb", r.Header.Get("Eth-Consensus-Version"))
-				var req shared.SignedBlindedBeaconBlockContentsDeneb
+				var req structs.SignedBlindedBeaconBlockDeneb
 				err := json.NewDecoder(r.Body).Decode(&req)
 				require.NoError(t, err)
-				block, err := req.SignedBlindedBlock.ToConsensus()
+				block, err := req.ToConsensus()
 				require.NoError(t, err)
-				require.DeepEqual(t, block, test.SignedBlindedBlock)
+				require.DeepEqual(t, block, test)
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadDeneb)),
@@ -423,10 +394,10 @@ func TestSubmitBlindedBlock(t *testing.T) {
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}

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

-		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb, test.SignedBlindedBlobSidecars)
+		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -436,9 +407,6 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 		require.NotNil(t, blobBundle)
-		require.Equal(t, hexutil.Encode(blobBundle.Blobs[0]), hexutil.Encode(make([]byte, fieldparams.BlobLength)))
-		require.Equal(t, hexutil.Encode(blobBundle.KzgCommitments[0]), "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f")
-		require.Equal(t, hexutil.Encode(blobBundle.Proofs[0]), "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a")
 	})
 	t.Run("mismatched versions, expected bellatrix got capella", func(t *testing.T) {
 		hc := &http.Client{
@@ -457,13 +425,13 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		_, _, err = c.SubmitBlindedBlock(ctx, sbbb, nil)
+		_, _, err = c.SubmitBlindedBlock(ctx, sbbb)
 		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{}}})
+		sbb, err := blocks.NewSignedBeaconBlock(&eth.SignedBeaconBlockBellatrix{Block: &eth.BeaconBlockBellatrix{Body: &eth.BeaconBlockBodyBellatrix{ExecutionPayload: &v1.ExecutionPayload{}}}})
 		require.NoError(t, err)
-		_, _, err = (&Client{}).SubmitBlindedBlock(ctx, sbb, nil)
+		_, _, err = (&Client{}).SubmitBlindedBlock(ctx, sbb)
 		require.ErrorIs(t, err, errNotBlinded)
 	})
 }
@@ -753,91 +721,70 @@ func testSignedBlindedBeaconBlockCapella(t *testing.T) *eth.SignedBlindedBeaconB
 	}
 }

-func testSignedBlindedBeaconBlockAndBlobsDeneb(t *testing.T) *eth.SignedBlindedBeaconBlockAndBlobsDeneb {
-	basebytes, err := shared.Uint256ToSSZBytes("14074904626401341155369551180448584754667373453244490859944217516317499064576")
+func testSignedBlindedBeaconBlockDeneb(t *testing.T) *eth.SignedBlindedBeaconBlockDeneb {
+	basebytes, err := bytesutil.Uint256ToSSZBytes("14074904626401341155369551180448584754667373453244490859944217516317499064576")
 	if err != nil {
 		log.Error(err)
 	}
-	return &eth.SignedBlindedBeaconBlockAndBlobsDeneb{
-		SignedBlindedBlock: &eth.SignedBlindedBeaconBlockDeneb{
-			Message: &eth.BlindedBeaconBlockDeneb{
-				Slot:          1,
-				ProposerIndex: 1,
-				ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-				StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-				Body: &eth.BlindedBeaconBlockBodyDeneb{
-					RandaoReveal: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
-					Eth1Data: &eth.Eth1Data{
-						DepositRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						DepositCount: 1,
-						BlockHash:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-					},
-					Graffiti: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-					ProposerSlashings: []*eth.ProposerSlashing{
-						{
-							Header_1: &eth.SignedBeaconBlockHeader{
-								Header: &eth.BeaconBlockHeader{
-									Slot:          1,
-									ProposerIndex: 1,
-									ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-								},
-								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+	return &eth.SignedBlindedBeaconBlockDeneb{
+		Message: &eth.BlindedBeaconBlockDeneb{
+			Slot:          1,
+			ProposerIndex: 1,
+			ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			Body: &eth.BlindedBeaconBlockBodyDeneb{
+				RandaoReveal: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+				Eth1Data: &eth.Eth1Data{
+					DepositRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					DepositCount: 1,
+					BlockHash:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+				Graffiti: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				ProposerSlashings: []*eth.ProposerSlashing{
+					{
+						Header_1: &eth.SignedBeaconBlockHeader{
+							Header: &eth.BeaconBlockHeader{
+								Slot:          1,
+								ProposerIndex: 1,
+								ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 							},
-							Header_2: &eth.SignedBeaconBlockHeader{
-								Header: &eth.BeaconBlockHeader{
-									Slot:          1,
-									ProposerIndex: 1,
-									ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-								},
-								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+						Header_2: &eth.SignedBeaconBlockHeader{
+							Header: &eth.BeaconBlockHeader{
+								Slot:          1,
+								ProposerIndex: 1,
+								ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
 					},
-					AttesterSlashings: []*eth.AttesterSlashing{
-						{
-							Attestation_1: &eth.IndexedAttestation{
-								AttestingIndices: []uint64{1},
-								Data: &eth.AttestationData{
-									Slot:            1,
-									CommitteeIndex:  1,
-									BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									Source: &eth.Checkpoint{
-										Epoch: 1,
-										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									},
-									Target: &eth.Checkpoint{
-										Epoch: 1,
-										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									},
+				},
+				AttesterSlashings: []*eth.AttesterSlashing{
+					{
+						Attestation_1: &eth.IndexedAttestation{
+							AttestingIndices: []uint64{1},
+							Data: &eth.AttestationData{
+								Slot:            1,
+								CommitteeIndex:  1,
+								BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Source: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 								},
-								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
-							},
-							Attestation_2: &eth.IndexedAttestation{
-								AttestingIndices: []uint64{1},
-								Data: &eth.AttestationData{
-									Slot:            1,
-									CommitteeIndex:  1,
-									BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									Source: &eth.Checkpoint{
-										Epoch: 1,
-										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									},
-									Target: &eth.Checkpoint{
-										Epoch: 1,
-										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-									},
+								Target: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 								},
-								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
-					},
-					Attestations: []*eth.Attestation{
-						{
-							AggregationBits: bitfield.Bitlist{0x01},
+						Attestation_2: &eth.IndexedAttestation{
+							AttestingIndices: []uint64{1},
 							Data: &eth.AttestationData{
 								Slot:            1,
 								CommitteeIndex:  1,
@@ -854,68 +801,72 @@ func testSignedBlindedBeaconBlockAndBlobsDeneb(t *testing.T) *eth.SignedBlindedB
 							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
 					},
-					Deposits: []*eth.Deposit{
-						{
-							Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
-							Data: &eth.Deposit_Data{
-								PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
-								WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-								Amount:                1,
-								Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+				},
+				Attestations: []*eth.Attestation{
+					{
+						AggregationBits: bitfield.Bitlist{0x01},
+						Data: &eth.AttestationData{
+							Slot:            1,
+							CommitteeIndex:  1,
+							BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							Source: &eth.Checkpoint{
+								Epoch: 1,
+								Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Target: &eth.Checkpoint{
+								Epoch: 1,
+								Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 							},
 						},
+						Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 					},
-					VoluntaryExits: []*eth.SignedVoluntaryExit{
-						{
-							Exit: &eth.VoluntaryExit{
-								Epoch:          1,
-								ValidatorIndex: 1,
-							},
-							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+				},
+				Deposits: []*eth.Deposit{
+					{
+						Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+						Data: &eth.Deposit_Data{
+							PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+							WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							Amount:                1,
+							Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 						},
 					},
-					SyncAggregate: &eth.SyncAggregate{
-						SyncCommitteeSignature: make([]byte, 96),
-						SyncCommitteeBits:      ezDecode(t, "0x6451e9f951ebf05edc01de67e593484b672877054f055903ff0df1a1a945cf30ca26bb4d4b154f94a1bc776bcf5d0efb3603e1f9b8ee2499ccdcfe2a18cef458"),
-					},
-					ExecutionPayloadHeader: &v1.ExecutionPayloadHeaderDeneb{
-						ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
-						StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
-						PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						BlockNumber:      1,
-						GasLimit:         1,
-						GasUsed:          1,
-						Timestamp:        1,
-						ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						BaseFeePerGas:    basebytes,
-						BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						WithdrawalsRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-						BlobGasUsed:      1,
-						ExcessBlobGas:    2,
+				},
+				VoluntaryExits: []*eth.SignedVoluntaryExit{
+					{
+						Exit: &eth.VoluntaryExit{
+							Epoch:          1,
+							ValidatorIndex: 1,
+						},
+						Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 					},
 				},
-			},
-			Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
-		},
-		SignedBlindedBlobSidecars: []*eth.SignedBlindedBlobSidecar{
-			{
-				Message: &eth.BlindedBlobSidecar{
-					BlockRoot:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-					Index:           0,
-					Slot:            1,
-					BlockParentRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
-					ProposerIndex:   1,
-					BlobRoot:        ezDecode(t, "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"),
-					KzgCommitment:   ezDecode(t, "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"),
-					KzgProof:        ezDecode(t, "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"),
+				SyncAggregate: &eth.SyncAggregate{
+					SyncCommitteeSignature: make([]byte, 96),
+					SyncCommitteeBits:      ezDecode(t, "0x6451e9f951ebf05edc01de67e593484b672877054f055903ff0df1a1a945cf30ca26bb4d4b154f94a1bc776bcf5d0efb3603e1f9b8ee2499ccdcfe2a18cef458"),
+				},
+				ExecutionPayloadHeader: &v1.ExecutionPayloadHeaderDeneb{
+					ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
+					StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+					PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BlockNumber:      1,
+					GasLimit:         1,
+					GasUsed:          1,
+					Timestamp:        1,
+					ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BaseFeePerGas:    basebytes,
+					BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					WithdrawalsRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BlobGasUsed:      1,
+					ExcessBlobGas:    2,
 				},
-				Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 			},
 		},
+		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 	}
 }

--- a/api/client/builder/testing/mock.go
+++ b/api/client/builder/testing/mock.go
@@ -41,7 +41,7 @@ func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedVali
 }

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

--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
@@ -117,7 +117,7 @@ type VersionResponse struct {
 	Version string `json:"version"`
 }

-// ExecHeaderResponse is a JSON representation of  the builder API header response for Bellatrix.
+// ExecHeaderResponse is a JSON representation of the builder API header response for Bellatrix.
 type ExecHeaderResponse struct {
 	Version string `json:"version"`
 	Data    struct {
@@ -357,6 +357,45 @@ 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 {
@@ -869,16 +908,19 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 	if err != nil {
 		return nil, err
 	}
-	var bundle *v1.BlindedBlobsBundle
-	if bb.BlindedBlobsBundle != nil {
-		bundle, err = bb.BlindedBlobsBundle.ToProto()
-		if err != nil {
-			return nil, err
+	if len(bb.BlobKzgCommitments) > fieldparams.MaxBlobsPerBlock {
+		return nil, fmt.Errorf("too many blob commitments: %d", len(bb.BlobKzgCommitments))
+	}
+	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
+	for i, commit := range bb.BlobKzgCommitments {
+		if len(commit) != fieldparams.BLSPubkeyLength {
+			return nil, fmt.Errorf("commitment length %d is not %d", len(commit), fieldparams.BLSPubkeyLength)
 		}
+		kzgCommitments[i] = bytesutil.SafeCopyBytes(commit)
 	}
 	return &eth.BuilderBidDeneb{
 		Header:             header,
-		BlindedBlobsBundle: bundle,
+		BlobKzgCommitments: kzgCommitments,
 		Value:              bytesutil.SafeCopyBytes(bb.Value.SSZBytes()),
 		Pubkey:             bytesutil.SafeCopyBytes(bb.Pubkey),
 	}, nil
@@ -887,42 +929,11 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 // BuilderBidDeneb is a field of ExecHeaderResponseDeneb.
 type BuilderBidDeneb struct {
 	Header             *ExecutionPayloadHeaderDeneb `json:"header"`
-	BlindedBlobsBundle *BlindedBlobsBundle          `json:"blinded_blobs_bundle"`
+	BlobKzgCommitments []hexutil.Bytes              `json:"blob_kzg_commitments"`
 	Value              Uint256                      `json:"value"`
 	Pubkey             hexutil.Bytes                `json:"pubkey"`
 }

-// BlindedBlobsBundle is a field of BuilderBidDeneb and represents the blinded blobs of the associated header.
-type BlindedBlobsBundle struct {
-	KzgCommitments []hexutil.Bytes `json:"commitments"`
-	Proofs         []hexutil.Bytes `json:"proofs"`
-	BlobRoots      []hexutil.Bytes `json:"blob_roots"`
-}
-
-// ToProto creates a BlindedBlobsBundle Proto from BlindedBlobsBundle.
-func (r *BlindedBlobsBundle) ToProto() (*v1.BlindedBlobsBundle, error) {
-	kzg := make([][]byte, len(r.KzgCommitments))
-	for i := range kzg {
-		kzg[i] = bytesutil.SafeCopyBytes(r.KzgCommitments[i])
-	}
-
-	proofs := make([][]byte, len(r.Proofs))
-	for i := range proofs {
-		proofs[i] = bytesutil.SafeCopyBytes(r.Proofs[i])
-	}
-
-	blobRoots := make([][]byte, len(r.BlobRoots))
-	for i := range blobRoots {
-		blobRoots[i] = bytesutil.SafeCopyBytes(r.BlobRoots[i])
-	}
-
-	return &v1.BlindedBlobsBundle{
-		KzgCommitments: kzg,
-		Proofs:         proofs,
-		BlobRoots:      blobRoots,
-	}, nil
-}
-
 // ExecutionPayloadHeaderDeneb a field part of the BuilderBidDeneb.
 type ExecutionPayloadHeaderDeneb struct {
 	ParentHash       hexutil.Bytes `json:"parent_hash"`
@@ -1052,6 +1063,16 @@ 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 {
@@ -1066,9 +1087,6 @@ 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 {
@@ -1083,6 +1101,28 @@ 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
@@ -13,7 +13,7 @@ import (

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	"github.com/prysmaticlabs/prysm/v4/api/server/structs"
 	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/math"
 	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
@@ -38,8 +38,7 @@ func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
 		},
 		Signature: make([]byte, 96),
 	}
-	a, err := shared.SignedValidatorRegistrationFromConsensus(svr)
-	require.NoError(t, err)
+	a := structs.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
@@ -56,7 +55,7 @@ func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
 	require.Equal(t, "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", un.Message.Pubkey)

 	t.Run("roundtrip", func(t *testing.T) {
-		b := &shared.SignedValidatorRegistration{}
+		b := &structs.SignedValidatorRegistration{}
 		if err := json.Unmarshal(je, b); err != nil {
 			require.NoError(t, err)
 		}
@@ -142,17 +141,9 @@ var testExampleHeaderResponseDeneb = `{
 		"blob_gas_used": "1",	
 		"excess_blob_gas": "2"	
      },
-      "blinded_blobs_bundle": {
-        "commitments": [
+      "blob_kzg_commitments": [
          "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
-        ],
-        "proofs": [
-          "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
-        ],
-        "blob_roots": [
-          "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"
-        ]
-      },
+	  ],
      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
    },
@@ -218,6 +209,39 @@ 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))
@@ -637,6 +661,151 @@ 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))
@@ -1013,7 +1182,6 @@ func TestExecutionPayloadResponseCapellaToProto(t *testing.T) {
 		},
 	}
 	require.DeepEqual(t, expected, p)
-
 }

 func TestExecutionPayloadResponseDenebToProto(t *testing.T) {
@@ -1092,7 +1260,27 @@ 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 {
@@ -1530,7 +1718,7 @@ func TestUint256UnmarshalTooBig(t *testing.T) {
 func TestMarshalBlindedBeaconBlockBodyBellatrix(t *testing.T) {
 	expected, err := os.ReadFile("testdata/blinded-block.json")
 	require.NoError(t, err)
-	b, err := shared.BlindedBeaconBlockBellatrixFromConsensus(&eth.BlindedBeaconBlockBellatrix{
+	b, err := structs.BlindedBeaconBlockBellatrixFromConsensus(&eth.BlindedBeaconBlockBellatrix{
 		Slot:          1,
 		ProposerIndex: 1,
 		ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
@@ -1560,7 +1748,7 @@ 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 := shared.BlindedBeaconBlockCapellaFromConsensus(&eth.BlindedBeaconBlockCapella{
+	b, err := structs.BlindedBeaconBlockCapellaFromConsensus(&eth.BlindedBeaconBlockCapella{
 		Slot:          1,
 		ProposerIndex: 1,
 		ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
--- 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 404:
+	case http.StatusNotFound:
 		return errors.Wrap(ErrNotFound, msg)
 	default:
 		return errors.Wrap(ErrNotOK, msg)
--- a/api/constants.go
+++ b/api/constants.go
@@ -0,0 +1,7 @@
+package api
+
+const (
+	WebUrlPrefix        = "/v2/validator/"
+	WebApiUrlPrefix     = "/api/v2/validator/"
+	KeymanagerApiPrefix = "/eth/v1"
+)
--- a/api/gateway/BUILD.bazel
+++ b/api/gateway/BUILD.bazel
@@ -14,12 +14,11 @@ go_library(
        "//validator:__subpackages__",
    ],
    deps = [
-        "//api/gateway/apimiddleware:go_default_library",
+        "//api/server:go_default_library",
        "//runtime:go_default_library",
        "@com_github_gorilla_mux//:go_default_library",
        "@com_github_grpc_ecosystem_grpc_gateway_v2//runtime:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
-        "@com_github_rs_cors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@org_golang_google_grpc//:go_default_library",
        "@org_golang_google_grpc//connectivity:go_default_library",
@@ -34,7 +33,6 @@ go_test(
    srcs = ["gateway_test.go"],
    embed = [":go_default_library"],
    deps = [
-        "//api/gateway/apimiddleware:go_default_library",
        "//cmd/beacon-chain/flags:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
--- a/api/gateway/apimiddleware/BUILD.bazel
+++ b/api/gateway/apimiddleware/BUILD.bazel
@@ -1,43 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "go_default_library",
-    srcs = [
-        "api_middleware.go",
-        "log.go",
-        "param_handling.go",
-        "process_field.go",
-        "process_request.go",
-        "structs.go",
-    ],
-    importpath = "github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware",
-    visibility = ["//visibility:public"],
-    deps = [
-        "//api:go_default_library",
-        "//api/grpc:go_default_library",
-        "//encoding/bytesutil:go_default_library",
-        "@com_github_ethereum_go_ethereum//common:go_default_library",
-        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
-        "@com_github_gorilla_mux//:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
-        "@com_github_wealdtech_go_bytesutil//:go_default_library",
-    ],
-)
-
-go_test(
-    name = "go_default_test",
-    srcs = [
-        "param_handling_test.go",
-        "process_request_test.go",
-    ],
-    embed = [":go_default_library"],
-    deps = [
-        "//api:go_default_library",
-        "//api/grpc:go_default_library",
-        "//testing/assert:go_default_library",
-        "//testing/require:go_default_library",
-        "@com_github_gorilla_mux//:go_default_library",
-        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
-    ],
-)
--- a/api/gateway/apimiddleware/api_middleware.go
+++ b/api/gateway/apimiddleware/api_middleware.go
@@ -1,265 +0,0 @@
-package apimiddleware
-
-import (
-	"net/http"
-	"reflect"
-	"time"
-
-	"github.com/gorilla/mux"
-)
-
-// ApiProxyMiddleware is a proxy between an Ethereum consensus API HTTP client and grpc-gateway.
-// The purpose of the proxy is to handle HTTP requests and gRPC responses in such a way that:
-//   - Ethereum consensus API requests can be handled by grpc-gateway correctly
-//   - gRPC responses can be returned as spec-compliant Ethereum consensus API responses
-type ApiProxyMiddleware struct {
-	GatewayAddress  string
-	EndpointCreator EndpointFactory
-	Timeout         time.Duration
-	router          *mux.Router
-}
-
-// EndpointFactory is responsible for creating new instances of Endpoint values.
-type EndpointFactory interface {
-	Create(path string) (*Endpoint, error)
-	Paths() []string
-	IsNil() bool
-}
-
-// Endpoint is a representation of an API HTTP endpoint that should be proxied by the middleware.
-type Endpoint struct {
-	Path               string          // The path of the HTTP endpoint.
-	GetResponse        interface{}     // The struct corresponding to the JSON structure used in a GET response.
-	PostRequest        interface{}     // The struct corresponding to the JSON structure used in a POST request.
-	PostResponse       interface{}     // The struct corresponding to the JSON structure used in a POST response.
-	DeleteRequest      interface{}     // The struct corresponding to the JSON structure used in a DELETE request.
-	DeleteResponse     interface{}     // The struct corresponding to the JSON structure used in a DELETE response.
-	RequestURLLiterals []string        // Names of URL parameters that should not be base64-encoded.
-	RequestQueryParams []QueryParam    // Query parameters of the request.
-	Err                ErrorJson       // The struct corresponding to the error that should be returned in case of a request failure.
-	Hooks              HookCollection  // A collection of functions that can be invoked at various stages of the request/response cycle.
-	CustomHandlers     []CustomHandler // Functions that will be executed instead of the default request/response behaviour.
-}
-
-// RunDefault expresses whether the default processing logic should be carried out after running a pre hook.
-type RunDefault bool
-
-// DefaultEndpoint returns an Endpoint with default configuration, e.g. DefaultErrorJson for error handling.
-func DefaultEndpoint() Endpoint {
-	return Endpoint{
-		Err: &DefaultErrorJson{},
-	}
-}
-
-// QueryParam represents a single query parameter's metadata.
-type QueryParam struct {
-	Name string
-	Hex  bool
-	Enum bool
-}
-
-// CustomHandler is a function that can be invoked at the very beginning of the request,
-// essentially replacing the whole default request/response logic with custom logic for a specific endpoint.
-type CustomHandler = func(m *ApiProxyMiddleware, endpoint Endpoint, w http.ResponseWriter, req *http.Request) (handled bool)
-
-// HookCollection contains hooks that can be used to amend the default request/response cycle with custom logic for a specific endpoint.
-type HookCollection struct {
-	OnPreDeserializeRequestBodyIntoContainer      func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) (RunDefault, ErrorJson)
-	OnPostDeserializeRequestBodyIntoContainer     func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson
-	OnPreDeserializeGrpcResponseBodyIntoContainer func([]byte, interface{}) (RunDefault, ErrorJson)
-	OnPreSerializeMiddlewareResponseIntoJson      func(interface{}) (RunDefault, []byte, ErrorJson)
-}
-
-// fieldProcessor applies the processing function f to a value when the tag is present on the field.
-type fieldProcessor struct {
-	tag string
-	f   func(value reflect.Value) error
-}
-
-// Run starts the proxy, registering all proxy endpoints.
-func (m *ApiProxyMiddleware) Run(gatewayRouter *mux.Router) {
-	for _, path := range m.EndpointCreator.Paths() {
-		gatewayRouter.HandleFunc(path, m.WithMiddleware(path))
-	}
-	m.router = gatewayRouter
-}
-
-// ServeHTTP for the proxy middleware.
-func (m *ApiProxyMiddleware) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-	m.router.ServeHTTP(w, req)
-}
-
-// WithMiddleware wraps the given endpoint handler with the middleware logic.
-func (m *ApiProxyMiddleware) WithMiddleware(path string) http.HandlerFunc {
-	return func(w http.ResponseWriter, req *http.Request) {
-		endpoint, err := m.EndpointCreator.Create(path)
-		if err != nil {
-			log.WithError(err).Errorf("Could not create endpoint for path: %s", path)
-			return
-		}
-
-		for _, handler := range endpoint.CustomHandlers {
-			if handler(m, *endpoint, w, req) {
-				return
-			}
-		}
-
-		if req.Method == "POST" {
-			if errJson := handlePostRequestForEndpoint(endpoint, w, req); errJson != nil {
-				WriteError(w, errJson, nil)
-				return
-			}
-		}
-
-		if req.Method == "DELETE" && req.Body != http.NoBody {
-			if errJson := handleDeleteRequestForEndpoint(endpoint, req); errJson != nil {
-				WriteError(w, errJson, nil)
-				return
-			}
-		}
-
-		if errJson := m.PrepareRequestForProxying(*endpoint, req); errJson != nil {
-			WriteError(w, errJson, nil)
-			return
-		}
-		grpcResp, errJson := m.ProxyRequest(req)
-		if errJson != nil {
-			WriteError(w, errJson, nil)
-			return
-		}
-		grpcRespBody, errJson := ReadGrpcResponseBody(grpcResp.Body)
-		if errJson != nil {
-			WriteError(w, errJson, nil)
-			return
-		}
-
-		var respJson []byte
-		if !GrpcResponseIsEmpty(grpcRespBody) {
-			respHasError, errJson := HandleGrpcResponseError(endpoint.Err, grpcResp, grpcRespBody, w)
-			if errJson != nil {
-				WriteError(w, errJson, nil)
-				return
-			}
-			if respHasError {
-				return
-			}
-
-			var resp interface{}
-			if req.Method == "GET" {
-				resp = endpoint.GetResponse
-			} else if req.Method == "DELETE" {
-				resp = endpoint.DeleteResponse
-			} else {
-				resp = endpoint.PostResponse
-			}
-			if errJson := deserializeGrpcResponseBodyIntoContainerWrapped(endpoint, grpcRespBody, resp); errJson != nil {
-				WriteError(w, errJson, nil)
-				return
-			}
-			if errJson := ProcessMiddlewareResponseFields(resp); errJson != nil {
-				WriteError(w, errJson, nil)
-				return
-			}
-
-			respJson, errJson = serializeMiddlewareResponseIntoJsonWrapped(endpoint, respJson, resp)
-			if errJson != nil {
-				WriteError(w, errJson, nil)
-				return
-			}
-		}
-
-		if errJson := WriteMiddlewareResponseHeadersAndBody(grpcResp, respJson, w); errJson != nil {
-			WriteError(w, errJson, nil)
-			return
-		}
-		if errJson := Cleanup(grpcResp.Body); errJson != nil {
-			WriteError(w, errJson, nil)
-			return
-		}
-	}
-}
-
-func handlePostRequestForEndpoint(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson {
-	if errJson := deserializeRequestBodyIntoContainerWrapped(endpoint, req, w); errJson != nil {
-		return errJson
-	}
-	if errJson := ProcessRequestContainerFields(endpoint.PostRequest); errJson != nil {
-		return errJson
-	}
-	return SetRequestBodyToRequestContainer(endpoint.PostRequest, req)
-}
-
-func handleDeleteRequestForEndpoint(endpoint *Endpoint, req *http.Request) ErrorJson {
-	if errJson := DeserializeRequestBodyIntoContainer(req.Body, endpoint.DeleteRequest); errJson != nil {
-		return errJson
-	}
-	if errJson := ProcessRequestContainerFields(endpoint.DeleteRequest); errJson != nil {
-		return errJson
-	}
-	return SetRequestBodyToRequestContainer(endpoint.DeleteRequest, req)
-}
-
-func deserializeRequestBodyIntoContainerWrapped(endpoint *Endpoint, req *http.Request, w http.ResponseWriter) ErrorJson {
-	runDefault := true
-	if endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer != nil {
-		run, errJson := endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer(endpoint, w, req)
-		if errJson != nil {
-			return errJson
-		}
-		if !run {
-			runDefault = false
-		}
-	}
-	if runDefault {
-		if errJson := DeserializeRequestBodyIntoContainer(req.Body, endpoint.PostRequest); errJson != nil {
-			return errJson
-		}
-	}
-	if endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer != nil {
-		if errJson := endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer(endpoint, w, req); errJson != nil {
-			return errJson
-		}
-	}
-	return nil
-}
-
-func deserializeGrpcResponseBodyIntoContainerWrapped(endpoint *Endpoint, grpcResponseBody []byte, resp interface{}) ErrorJson {
-	runDefault := true
-	if endpoint.Hooks.OnPreDeserializeGrpcResponseBodyIntoContainer != nil {
-		run, errJson := endpoint.Hooks.OnPreDeserializeGrpcResponseBodyIntoContainer(grpcResponseBody, resp)
-		if errJson != nil {
-			return errJson
-		}
-		if !run {
-			runDefault = false
-		}
-	}
-	if runDefault {
-		if errJson := DeserializeGrpcResponseBodyIntoContainer(grpcResponseBody, resp); errJson != nil {
-			return errJson
-		}
-	}
-	return nil
-}
-
-func serializeMiddlewareResponseIntoJsonWrapped(endpoint *Endpoint, respJson []byte, resp interface{}) ([]byte, ErrorJson) {
-	runDefault := true
-	var errJson ErrorJson
-	if endpoint.Hooks.OnPreSerializeMiddlewareResponseIntoJson != nil {
-		var run RunDefault
-		run, respJson, errJson = endpoint.Hooks.OnPreSerializeMiddlewareResponseIntoJson(resp)
-		if errJson != nil {
-			return nil, errJson
-		}
-		if !run {
-			runDefault = false
-		}
-	}
-	if runDefault {
-		respJson, errJson = SerializeMiddlewareResponseIntoJson(resp)
-		if errJson != nil {
-			return nil, errJson
-		}
-	}
-	return respJson, nil
-}
--- a/api/gateway/apimiddleware/log.go
+++ b/api/gateway/apimiddleware/log.go
@@ -1,5 +0,0 @@
-package apimiddleware
-
-import "github.com/sirupsen/logrus"
-
-var log = logrus.WithField("prefix", "apimiddleware")
--- a/api/gateway/apimiddleware/param_handling.go
+++ b/api/gateway/apimiddleware/param_handling.go
@@ -1,103 +0,0 @@
-package apimiddleware
-
-import (
-	"encoding/base64"
-	"net/http"
-	"net/url"
-	"strings"
-
-	"github.com/gorilla/mux"
-	butil "github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
-	"github.com/wealdtech/go-bytesutil"
-)
-
-// HandleURLParameters processes URL parameters, allowing parameterized URLs to be safely and correctly proxied to grpc-gateway.
-func HandleURLParameters(url string, req *http.Request, literals []string) ErrorJson {
-	segments := strings.Split(url, "/")
-
-segmentsLoop:
-	for i, s := range segments {
-		// We only care about segments which are parameterized.
-		if isRequestParam(s) {
-			// Don't do anything with parameters which should be forwarded literally to gRPC.
-			for _, l := range literals {
-				if s == "{"+l+"}" {
-					continue segmentsLoop
-				}
-			}
-
-			routeVar := mux.Vars(req)[s[1:len(s)-1]]
-			bRouteVar := []byte(routeVar)
-			if butil.IsHex(bRouteVar) {
-				var err error
-				bRouteVar, err = bytesutil.FromHexString(string(bRouteVar))
-				if err != nil {
-					return InternalServerErrorWithMessage(err, "could not process URL parameter")
-				}
-			}
-			// Converting hex to base64 may result in a value which malforms the URL.
-			// We use URLEncoding to safely escape such values.
-			base64RouteVar := base64.URLEncoding.EncodeToString(bRouteVar)
-
-			// Merge segments back into the full URL.
-			splitPath := strings.Split(req.URL.Path, "/")
-			splitPath[i] = base64RouteVar
-			req.URL.Path = strings.Join(splitPath, "/")
-		}
-	}
-	return nil
-}
-
-// HandleQueryParameters processes query parameters, allowing them to be safely and correctly proxied to grpc-gateway.
-func HandleQueryParameters(req *http.Request, params []QueryParam) ErrorJson {
-	queryParams := req.URL.Query()
-
-	normalizeQueryValues(queryParams)
-
-	for key, vals := range queryParams {
-		for _, p := range params {
-			if key == p.Name {
-				if p.Hex {
-					queryParams.Del(key)
-					for _, v := range vals {
-						b := []byte(v)
-						if butil.IsHex(b) {
-							var err error
-							b, err = bytesutil.FromHexString(v)
-							if err != nil {
-								return InternalServerErrorWithMessage(err, "could not process query parameter")
-							}
-						}
-						queryParams.Add(key, base64.URLEncoding.EncodeToString(b))
-					}
-				}
-				if p.Enum {
-					queryParams.Del(key)
-					for _, v := range vals {
-						// gRPC expects uppercase enum values.
-						queryParams.Add(key, strings.ToUpper(v))
-					}
-				}
-			}
-		}
-	}
-	req.URL.RawQuery = queryParams.Encode()
-	return nil
-}
-
-// isRequestParam verifies whether the passed string is a request parameter.
-// Request parameters are enclosed in { and }.
-func isRequestParam(s string) bool {
-	return len(s) > 2 && s[0] == '{' && s[len(s)-1] == '}'
-}
-
-func normalizeQueryValues(queryParams url.Values) {
-	// Replace comma-separated values with individual values.
-	for key, vals := range queryParams {
-		splitVals := make([]string, 0)
-		for _, v := range vals {
-			splitVals = append(splitVals, strings.Split(v, ",")...)
-		}
-		queryParams[key] = splitVals
-	}
-}
--- a/api/gateway/apimiddleware/param_handling_test.go
+++ b/api/gateway/apimiddleware/param_handling_test.go
@@ -1,124 +0,0 @@
-package apimiddleware
-
-import (
-	"bytes"
-	"net/http/httptest"
-	"testing"
-
-	"github.com/gorilla/mux"
-	"github.com/prysmaticlabs/prysm/v4/testing/assert"
-	"github.com/prysmaticlabs/prysm/v4/testing/require"
-)
-
-func TestHandleURLParameters(t *testing.T) {
-	var body bytes.Buffer
-
-	t.Run("no_params", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example/bar", &body)
-
-		errJson := HandleURLParameters("/not_param", request, []string{})
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "/bar", request.URL.Path)
-	})
-
-	t.Run("with_params", func(t *testing.T) {
-		muxVars := make(map[string]string)
-		muxVars["bar_param"] = "bar"
-		muxVars["quux_param"] = "quux"
-		request := httptest.NewRequest("GET", "http://foo.example/bar/baz/quux", &body)
-		request = mux.SetURLVars(request, muxVars)
-
-		errJson := HandleURLParameters("/{bar_param}/not_param/{quux_param}", request, []string{})
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "/YmFy/baz/cXV1eA==", request.URL.Path)
-	})
-
-	t.Run("with_literal", func(t *testing.T) {
-		muxVars := make(map[string]string)
-		muxVars["bar_param"] = "bar"
-		request := httptest.NewRequest("GET", "http://foo.example/bar/baz", &body)
-		request = mux.SetURLVars(request, muxVars)
-
-		errJson := HandleURLParameters("/{bar_param}/not_param/", request, []string{"bar_param"})
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "/bar/baz", request.URL.Path)
-	})
-
-	t.Run("with_hex", func(t *testing.T) {
-		muxVars := make(map[string]string)
-		muxVars["hex_param"] = "0x626172"
-		request := httptest.NewRequest("GET", "http://foo.example/0x626172/baz", &body)
-		request = mux.SetURLVars(request, muxVars)
-
-		errJson := HandleURLParameters("/{hex_param}/not_param/", request, []string{})
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "/YmFy/baz", request.URL.Path)
-	})
-}
-
-func TestHandleQueryParameters(t *testing.T) {
-	var body bytes.Buffer
-
-	t.Run("regular_params", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example?bar=bar&baz=baz", &body)
-
-		errJson := HandleQueryParameters(request, []QueryParam{{Name: "bar"}, {Name: "baz"}})
-		require.Equal(t, true, errJson == nil)
-		query := request.URL.Query()
-		v, ok := query["bar"]
-		require.Equal(t, true, ok, "query param not found")
-		require.Equal(t, 1, len(v), "wrong number of query param values")
-		assert.Equal(t, "bar", v[0])
-		v, ok = query["baz"]
-		require.Equal(t, true, ok, "query param not found")
-		require.Equal(t, 1, len(v), "wrong number of query param values")
-		assert.Equal(t, "baz", v[0])
-	})
-
-	t.Run("hex_and_enum_params", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example?hex=0x626172&baz=baz", &body)
-
-		errJson := HandleQueryParameters(request, []QueryParam{{Name: "hex", Hex: true}, {Name: "baz", Enum: true}})
-		require.Equal(t, true, errJson == nil)
-		query := request.URL.Query()
-		v, ok := query["hex"]
-		require.Equal(t, true, ok, "query param not found")
-		require.Equal(t, 1, len(v), "wrong number of query param values")
-		assert.Equal(t, "YmFy", v[0])
-		v, ok = query["baz"]
-		require.Equal(t, true, ok, "query param not found")
-		require.Equal(t, 1, len(v), "wrong number of query param values")
-		assert.Equal(t, "BAZ", v[0])
-	})
-}
-
-func TestIsRequestParam(t *testing.T) {
-	tests := []struct {
-		s string
-		b bool
-	}{
-		{"", false},
-		{"{", false},
-		{"}", false},
-		{"{}", false},
-		{"{x}", true},
-		{"{very_long_parameter_name_with_underscores}", true},
-	}
-	for _, tt := range tests {
-		b := isRequestParam(tt.s)
-		assert.Equal(t, tt.b, b)
-	}
-}
-
-func TestNormalizeQueryValues(t *testing.T) {
-	input := make(map[string][]string)
-	input["key"] = []string{"value1", "value2,value3,value4", "value5"}
-
-	normalizeQueryValues(input)
-	require.Equal(t, 5, len(input["key"]))
-	assert.Equal(t, "value1", input["key"][0])
-	assert.Equal(t, "value2", input["key"][1])
-	assert.Equal(t, "value3", input["key"][2])
-	assert.Equal(t, "value4", input["key"][3])
-	assert.Equal(t, "value5", input["key"][4])
-}
--- a/api/gateway/apimiddleware/process_field.go
+++ b/api/gateway/apimiddleware/process_field.go
@@ -1,179 +0,0 @@
-package apimiddleware
-
-import (
-	"encoding/base64"
-	"fmt"
-	"math/big"
-	"reflect"
-	"strconv"
-	"strings"
-	"time"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/pkg/errors"
-	"github.com/wealdtech/go-bytesutil"
-)
-
-// processField calls each processor function on any field that has the matching tag set.
-// It is a recursive function.
-func processField(s interface{}, processors []fieldProcessor) error {
-	kind := reflect.TypeOf(s).Kind()
-	if kind != reflect.Ptr && kind != reflect.Slice && kind != reflect.Array {
-		return fmt.Errorf("processing fields of kind '%v' is unsupported", kind)
-	}
-
-	t := reflect.TypeOf(s).Elem()
-	v := reflect.Indirect(reflect.ValueOf(s))
-
-	for i := 0; i < t.NumField(); i++ {
-		switch v.Field(i).Kind() {
-		case reflect.Slice:
-			sliceElem := t.Field(i).Type.Elem()
-			kind := sliceElem.Kind()
-			// Recursively process slices to struct pointers.
-			switch {
-			case kind == reflect.Ptr && sliceElem.Elem().Kind() == reflect.Struct:
-				for j := 0; j < v.Field(i).Len(); j++ {
-					if err := processField(v.Field(i).Index(j).Interface(), processors); err != nil {
-						return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
-					}
-				}
-			// Process each string in string slices.
-			case kind == reflect.String:
-				for _, proc := range processors {
-					_, hasTag := t.Field(i).Tag.Lookup(proc.tag)
-					if !hasTag {
-						continue
-					}
-					for j := 0; j < v.Field(i).Len(); j++ {
-						if err := proc.f(v.Field(i).Index(j)); err != nil {
-							return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
-						}
-					}
-				}
-			}
-		// Recursively process struct pointers.
-		case reflect.Ptr:
-			if v.Field(i).Elem().Kind() == reflect.Struct {
-				if err := processField(v.Field(i).Interface(), processors); err != nil {
-					return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
-				}
-			}
-		default:
-			field := t.Field(i)
-			for _, proc := range processors {
-				if _, hasTag := field.Tag.Lookup(proc.tag); hasTag {
-					if err := proc.f(v.Field(i)); err != nil {
-						return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
-					}
-				}
-			}
-		}
-	}
-	return nil
-}
-
-func hexToBase64Processor(v reflect.Value) error {
-	if v.String() == "0x" {
-		v.SetString("")
-		return nil
-	}
-	b, err := bytesutil.FromHexString(v.String())
-	if err != nil {
-		return err
-	}
-	v.SetString(base64.StdEncoding.EncodeToString(b))
-	return nil
-}
-
-func base64ToHexProcessor(v reflect.Value) error {
-	if v.String() == "" {
-		// Empty hex values are represented as "0x".
-		v.SetString("0x")
-		return nil
-	}
-	b, err := base64.StdEncoding.DecodeString(v.String())
-	if err != nil {
-		return err
-	}
-	v.SetString(hexutil.Encode(b))
-	return nil
-}
-
-func base64ToChecksumAddressProcessor(v reflect.Value) error {
-	if v.String() == "" {
-		// Empty hex values are represented as "0x".
-		v.SetString("0x")
-		return nil
-	}
-	b, err := base64.StdEncoding.DecodeString(v.String())
-	if err != nil {
-		return err
-	}
-	v.SetString(common.BytesToAddress(b).Hex())
-	return nil
-}
-
-func base64ToUint256Processor(v reflect.Value) error {
-	if v.String() == "" {
-		return nil
-	}
-	littleEndian, err := base64.StdEncoding.DecodeString(v.String())
-	if err != nil {
-		return err
-	}
-	if len(littleEndian) != 32 {
-		return errors.New("invalid length for Uint256")
-	}
-
-	// Integers are stored as little-endian, but
-	// big.Int expects big-endian. So we need to reverse
-	// the byte order before decoding.
-	var bigEndian [32]byte
-	for i := 0; i < len(littleEndian); i++ {
-		bigEndian[i] = littleEndian[len(littleEndian)-1-i]
-	}
-	var uint256 big.Int
-	uint256.SetBytes(bigEndian[:])
-	v.SetString(uint256.String())
-	return nil
-}
-
-func uint256ToBase64Processor(v reflect.Value) error {
-	if v.String() == "" {
-		return nil
-	}
-	uint256, ok := new(big.Int).SetString(v.String(), 10)
-	if !ok {
-		return fmt.Errorf("could not parse Uint256")
-	}
-	bigEndian := uint256.Bytes()
-	if len(bigEndian) > 32 {
-		return fmt.Errorf("number too big for Uint256")
-	}
-
-	// Integers are stored as little-endian, but
-	// big.Int gives big-endian. So we need to reverse
-	// the byte order before encoding.
-	var littleEndian [32]byte
-	for i := 0; i < len(bigEndian); i++ {
-		littleEndian[i] = bigEndian[len(bigEndian)-1-i]
-	}
-	v.SetString(base64.StdEncoding.EncodeToString(littleEndian[:]))
-	return nil
-}
-
-func enumToLowercaseProcessor(v reflect.Value) error {
-	v.SetString(strings.ToLower(v.String()))
-	return nil
-}
-
-func timeToUnixProcessor(v reflect.Value) error {
-	t, err := time.Parse(time.RFC3339, v.String())
-	if err != nil {
-		return err
-	}
-	v.SetString(strconv.FormatUint(uint64(t.Unix()), 10))
-	return nil
-}
--- a/api/gateway/apimiddleware/process_request.go
+++ b/api/gateway/apimiddleware/process_request.go
@@ -1,283 +0,0 @@
-package apimiddleware
-
-import (
-	"bytes"
-	"encoding/json"
-	"io"
-	"net"
-	"net/http"
-	"strconv"
-	"strings"
-
-	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v4/api"
-	"github.com/prysmaticlabs/prysm/v4/api/grpc"
-)
-
-// DeserializeRequestBodyIntoContainer deserializes the request's body into an endpoint-specific struct.
-func DeserializeRequestBodyIntoContainer(body io.Reader, requestContainer interface{}) ErrorJson {
-	decoder := json.NewDecoder(body)
-	decoder.DisallowUnknownFields()
-	if err := decoder.Decode(&requestContainer); err != nil {
-		if strings.Contains(err.Error(), "json: unknown field") {
-			e := errors.Wrap(err, "could not decode request body")
-			return &DefaultErrorJson{
-				Message: e.Error(),
-				Code:    http.StatusBadRequest,
-			}
-		}
-		return InternalServerErrorWithMessage(err, "could not decode request body")
-	}
-	return nil
-}
-
-// ProcessRequestContainerFields processes fields of an endpoint-specific container according to field tags.
-func ProcessRequestContainerFields(requestContainer interface{}) ErrorJson {
-	if err := processField(requestContainer, []fieldProcessor{
-		{
-			tag: "hex",
-			f:   hexToBase64Processor,
-		},
-		{
-			tag: "uint256",
-			f:   uint256ToBase64Processor,
-		},
-	}); err != nil {
-		return InternalServerErrorWithMessage(err, "could not process request data")
-	}
-	return nil
-}
-
-// SetRequestBodyToRequestContainer makes the endpoint-specific container the new body of the request.
-func SetRequestBodyToRequestContainer(requestContainer interface{}, req *http.Request) ErrorJson {
-	// Serialize the struct, which now includes a base64-encoded value, into JSON.
-	j, err := json.Marshal(requestContainer)
-	if err != nil {
-		return InternalServerErrorWithMessage(err, "could not marshal request")
-	}
-	// Set the body to the new JSON.
-	req.Body = io.NopCloser(bytes.NewReader(j))
-	req.Header.Set("Content-Length", strconv.Itoa(len(j)))
-	req.ContentLength = int64(len(j))
-	return nil
-}
-
-// PrepareRequestForProxying applies additional logic to the request so that it can be correctly proxied to grpc-gateway.
-func (m *ApiProxyMiddleware) PrepareRequestForProxying(endpoint Endpoint, req *http.Request) ErrorJson {
-	req.URL.Scheme = "http"
-	req.URL.Host = m.GatewayAddress
-	req.RequestURI = ""
-	if errJson := HandleURLParameters(endpoint.Path, req, endpoint.RequestURLLiterals); errJson != nil {
-		return errJson
-	}
-	if errJson := HandleQueryParameters(req, endpoint.RequestQueryParams); errJson != nil {
-		return errJson
-	}
-	// We have to add the prefix after handling parameters because adding the prefix changes URL segment indexing.
-	req.URL.Path = "/internal" + req.URL.Path
-	return nil
-}
-
-// ProxyRequest proxies the request to grpc-gateway.
-func (m *ApiProxyMiddleware) ProxyRequest(req *http.Request) (*http.Response, ErrorJson) {
-	// We do not use http.DefaultClient because it does not have any timeout.
-	netClient := &http.Client{Timeout: m.Timeout}
-	grpcResp, err := netClient.Do(req)
-	if err != nil {
-		if err, ok := err.(net.Error); ok && err.Timeout() {
-			return nil, TimeoutError()
-		}
-		return nil, InternalServerErrorWithMessage(err, "could not proxy request")
-	}
-	if grpcResp == nil {
-		return nil, &DefaultErrorJson{Message: "nil response from gRPC-gateway", Code: http.StatusInternalServerError}
-	}
-	return grpcResp, nil
-}
-
-// ReadGrpcResponseBody reads the body from the grpc-gateway's response.
-func ReadGrpcResponseBody(r io.Reader) ([]byte, ErrorJson) {
-	body, err := io.ReadAll(r)
-	if err != nil {
-		return nil, InternalServerErrorWithMessage(err, "could not read response body")
-	}
-	return body, nil
-}
-
-// HandleGrpcResponseError acts on an error that resulted from a grpc-gateway's response.
-// Whether there was an error is indicated by the bool return value. In case of an error,
-// there is no need to write to the response because it's taken care of by the function.
-func HandleGrpcResponseError(errJson ErrorJson, resp *http.Response, respBody []byte, w http.ResponseWriter) (bool, ErrorJson) {
-	responseHasError := false
-	if err := json.Unmarshal(respBody, errJson); err != nil {
-		return false, InternalServerErrorWithMessage(err, "could not unmarshal error")
-	}
-	if errJson.Msg() != "" {
-		responseHasError = true
-		// Something went wrong, but the request completed, meaning we can write headers and the error message.
-		for h, vs := range resp.Header {
-			for _, v := range vs {
-				if strings.HasSuffix(h, api.VersionHeader) {
-					w.Header().Set(api.VersionHeader, v)
-				} else {
-					w.Header().Set(h, v)
-				}
-			}
-		}
-		// Handle gRPC timeout.
-		if resp.StatusCode == http.StatusGatewayTimeout {
-			WriteError(w, TimeoutError(), resp.Header)
-		} else {
-			// Set code to HTTP code because unmarshalled body contained gRPC code.
-			errJson.SetCode(resp.StatusCode)
-			WriteError(w, errJson, resp.Header)
-		}
-	}
-	return responseHasError, nil
-}
-
-// GrpcResponseIsEmpty determines whether the grpc-gateway's response body contains no data.
-func GrpcResponseIsEmpty(grpcResponseBody []byte) bool {
-	return len(grpcResponseBody) == 0 || string(grpcResponseBody) == "{}"
-}
-
-// DeserializeGrpcResponseBodyIntoContainer deserializes the grpc-gateway's response body into an endpoint-specific struct.
-func DeserializeGrpcResponseBodyIntoContainer(body []byte, responseContainer interface{}) ErrorJson {
-	if err := json.Unmarshal(body, &responseContainer); err != nil {
-		return InternalServerErrorWithMessage(err, "could not unmarshal response")
-	}
-	return nil
-}
-
-// ProcessMiddlewareResponseFields processes fields of an endpoint-specific container according to field tags.
-func ProcessMiddlewareResponseFields(responseContainer interface{}) ErrorJson {
-	if err := processField(responseContainer, []fieldProcessor{
-		{
-			tag: "hex",
-			f:   base64ToHexProcessor,
-		},
-		{
-			tag: "address",
-			f:   base64ToChecksumAddressProcessor,
-		},
-		{
-			tag: "enum",
-			f:   enumToLowercaseProcessor,
-		},
-		{
-			tag: "time",
-			f:   timeToUnixProcessor,
-		},
-		{
-			tag: "uint256",
-			f:   base64ToUint256Processor,
-		},
-	}); err != nil {
-		return InternalServerErrorWithMessage(err, "could not process response data")
-	}
-	return nil
-}
-
-// SerializeMiddlewareResponseIntoJson serializes the endpoint-specific response struct into a JSON representation.
-func SerializeMiddlewareResponseIntoJson(responseContainer interface{}) (jsonResponse []byte, errJson ErrorJson) {
-	j, err := json.Marshal(responseContainer)
-	if err != nil {
-		return nil, InternalServerErrorWithMessage(err, "could not marshal response")
-	}
-	return j, nil
-}
-
-// WriteMiddlewareResponseHeadersAndBody populates headers and the body of the final response.
-func WriteMiddlewareResponseHeadersAndBody(grpcResp *http.Response, responseJson []byte, w http.ResponseWriter) ErrorJson {
-	var statusCodeHeader string
-	for h, vs := range grpcResp.Header {
-		// We don't want to expose any gRPC metadata in the HTTP response, so we skip forwarding metadata headers.
-		if strings.HasPrefix(h, grpc.MetadataPrefix) {
-			if h == grpc.WithPrefix(grpc.HttpCodeMetadataKey) {
-				statusCodeHeader = vs[0]
-			} else if strings.HasSuffix(h, api.VersionHeader) {
-				w.Header().Set(api.VersionHeader, vs[0])
-			}
-		} else {
-			for _, v := range vs {
-				w.Header().Set(h, v)
-			}
-		}
-	}
-	if !GrpcResponseIsEmpty(responseJson) {
-		w.Header().Set("Content-Length", strconv.Itoa(len(responseJson)))
-		if statusCodeHeader != "" {
-			code, err := strconv.Atoi(statusCodeHeader)
-			if err != nil {
-				return InternalServerErrorWithMessage(err, "could not parse status code")
-			}
-			w.WriteHeader(code)
-		} else {
-			w.WriteHeader(grpcResp.StatusCode)
-		}
-		if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(responseJson))); err != nil {
-			return InternalServerErrorWithMessage(err, "could not write response message")
-		}
-	} else {
-		w.Header().Set("Content-Length", "0")
-		w.WriteHeader(grpcResp.StatusCode)
-	}
-	return nil
-}
-
-// WriteError writes the error by manipulating headers and the body of the final response.
-func WriteError(w http.ResponseWriter, errJson ErrorJson, responseHeader http.Header) {
-	// Include custom error in the error JSON.
-	hasCustomError := false
-	if responseHeader != nil {
-		customError, ok := responseHeader[grpc.WithPrefix(grpc.CustomErrorMetadataKey)]
-		if ok {
-			hasCustomError = true
-			// Assume header has only one value and read the 0 index.
-			if err := json.Unmarshal([]byte(customError[0]), errJson); err != nil {
-				log.WithError(err).Error("Could not unmarshal custom error message")
-				return
-			}
-		}
-	}
-
-	var j []byte
-	if hasCustomError {
-		var err error
-		j, err = json.Marshal(errJson)
-		if err != nil {
-			log.WithError(err).Error("Could not marshal error message")
-			return
-		}
-	} else {
-		var err error
-		// We marshal the response body into a DefaultErrorJson if the custom error is not present.
-		// This is because the ErrorJson argument is the endpoint's error definition, which may contain custom fields.
-		// In such a scenario marhaling the endpoint's error would populate the resulting JSON
-		// with these fields even if they are not present in the gRPC header.
-		d := &DefaultErrorJson{
-			Message: errJson.Msg(),
-			Code:    errJson.StatusCode(),
-		}
-		j, err = json.Marshal(d)
-		if err != nil {
-			log.WithError(err).Error("Could not marshal error message")
-			return
-		}
-	}
-
-	w.Header().Set("Content-Length", strconv.Itoa(len(j)))
-	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(errJson.StatusCode())
-	if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(j))); err != nil {
-		log.WithError(err).Error("Could not write error message")
-	}
-}
-
-// Cleanup performs final cleanup on the initial response from grpc-gateway.
-func Cleanup(grpcResponseBody io.ReadCloser) ErrorJson {
-	if err := grpcResponseBody.Close(); err != nil {
-		return InternalServerErrorWithMessage(err, "could not close response body")
-	}
-	return nil
-}
--- a/api/gateway/apimiddleware/process_request_test.go
+++ b/api/gateway/apimiddleware/process_request_test.go
@@ -1,435 +0,0 @@
-package apimiddleware
-
-import (
-	"bytes"
-	"encoding/json"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"testing"
-
-	"github.com/prysmaticlabs/prysm/v4/api"
-	"github.com/prysmaticlabs/prysm/v4/api/grpc"
-	"github.com/prysmaticlabs/prysm/v4/testing/assert"
-	"github.com/prysmaticlabs/prysm/v4/testing/require"
-	"github.com/sirupsen/logrus/hooks/test"
-)
-
-type testRequestContainer struct {
-	TestString         string
-	TestHexString      string `hex:"true"`
-	TestEmptyHexString string `hex:"true"`
-	TestUint256String  string `uint256:"true"`
-}
-
-func defaultRequestContainer() *testRequestContainer {
-	return &testRequestContainer{
-		TestString:         "test string",
-		TestHexString:      "0x666F6F", // hex encoding of "foo"
-		TestEmptyHexString: "0x",
-		TestUint256String:  "4196",
-	}
-}
-
-type testResponseContainer struct {
-	TestString       string
-	TestHex          string `hex:"true"`
-	TestEmptyHex     string `hex:"true"`
-	TestAddress      string `address:"true"`
-	TestEmptyAddress string `address:"true"`
-	TestUint256      string `uint256:"true"`
-	TestEnum         string `enum:"true"`
-	TestTime         string `time:"true"`
-}
-
-func defaultResponseContainer() *testResponseContainer {
-	return &testResponseContainer{
-		TestString:       "test string",
-		TestHex:          "Zm9v", // base64 encoding of "foo"
-		TestEmptyHex:     "",
-		TestAddress:      "Zm9v",
-		TestEmptyAddress: "",
-		TestEnum:         "Test Enum",
-		TestTime:         "2006-01-02T15:04:05Z",
-
-		// base64 encoding of 4196 in little-endian
-		TestUint256: "ZBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
-	}
-}
-
-type testErrorJson struct {
-	Message     string
-	Code        int
-	CustomField string
-}
-
-// StatusCode returns the error's underlying error code.
-func (e *testErrorJson) StatusCode() int {
-	return e.Code
-}
-
-// Msg returns the error's underlying message.
-func (e *testErrorJson) Msg() string {
-	return e.Message
-}
-
-// SetCode sets the error's underlying error code.
-func (e *testErrorJson) SetCode(code int) {
-	e.Code = code
-}
-
-// SetMsg sets the error's underlying message.
-func (e *testErrorJson) SetMsg(msg string) {
-	e.Message = msg
-}
-
-func TestDeserializeRequestBodyIntoContainer(t *testing.T) {
-	t.Run("ok", func(t *testing.T) {
-		var bodyJson bytes.Buffer
-		err := json.NewEncoder(&bodyJson).Encode(defaultRequestContainer())
-		require.NoError(t, err)
-
-		container := &testRequestContainer{}
-		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, container)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "test string", container.TestString)
-	})
-
-	t.Run("error", func(t *testing.T) {
-		var bodyJson bytes.Buffer
-		bodyJson.Write([]byte("foo"))
-		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
-		require.NotNil(t, errJson)
-		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
-		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
-	})
-
-	t.Run("unknown field", func(t *testing.T) {
-		var bodyJson bytes.Buffer
-		bodyJson.Write([]byte("{\"foo\":\"foo\"}"))
-		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
-		require.NotNil(t, errJson)
-		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
-		assert.Equal(t, http.StatusBadRequest, errJson.StatusCode())
-	})
-}
-
-func TestProcessRequestContainerFields(t *testing.T) {
-	t.Run("ok", func(t *testing.T) {
-		container := defaultRequestContainer()
-
-		errJson := ProcessRequestContainerFields(container)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "Zm9v", container.TestHexString)
-		assert.Equal(t, "", container.TestEmptyHexString)
-		assert.Equal(t, "ZBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=", container.TestUint256String)
-	})
-
-	t.Run("error", func(t *testing.T) {
-		errJson := ProcessRequestContainerFields("foo")
-		require.NotNil(t, errJson)
-		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not process request data"))
-		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
-	})
-}
-
-func TestSetRequestBodyToRequestContainer(t *testing.T) {
-	var body bytes.Buffer
-	request := httptest.NewRequest("GET", "http://foo.example", &body)
-
-	errJson := SetRequestBodyToRequestContainer(defaultRequestContainer(), request)
-	require.Equal(t, true, errJson == nil)
-	container := &testRequestContainer{}
-	require.NoError(t, json.NewDecoder(request.Body).Decode(container))
-	assert.Equal(t, "test string", container.TestString)
-	contentLengthHeader, ok := request.Header["Content-Length"]
-	require.Equal(t, true, ok)
-	require.Equal(t, 1, len(contentLengthHeader), "wrong number of header values")
-	assert.Equal(t, "108", contentLengthHeader[0])
-	assert.Equal(t, int64(108), request.ContentLength)
-}
-
-func TestPrepareRequestForProxying(t *testing.T) {
-	middleware := &ApiProxyMiddleware{
-		GatewayAddress: "http://gateway.example",
-	}
-	// We will set some params to make the request more interesting.
-	endpoint := Endpoint{
-		Path:               "/{url_param}",
-		RequestURLLiterals: []string{"url_param"},
-		RequestQueryParams: []QueryParam{{Name: "query_param"}},
-	}
-	var body bytes.Buffer
-	request := httptest.NewRequest("GET", "http://foo.example?query_param=bar", &body)
-
-	errJson := middleware.PrepareRequestForProxying(endpoint, request)
-	require.Equal(t, true, errJson == nil)
-	assert.Equal(t, "http", request.URL.Scheme)
-	assert.Equal(t, middleware.GatewayAddress, request.URL.Host)
-	assert.Equal(t, "", request.RequestURI)
-}
-
-func TestReadGrpcResponseBody(t *testing.T) {
-	var b bytes.Buffer
-	b.Write([]byte("foo"))
-
-	body, jsonErr := ReadGrpcResponseBody(&b)
-	require.Equal(t, true, jsonErr == nil)
-	assert.Equal(t, "foo", string(body))
-}
-
-func TestHandleGrpcResponseError(t *testing.T) {
-	response := &http.Response{
-		StatusCode: 400,
-		Header: http.Header{
-			"Foo": []string{"foo"},
-			"Bar": []string{"bar"},
-		},
-	}
-	writer := httptest.NewRecorder()
-	errJson := &testErrorJson{
-		Message: "foo",
-		Code:    400,
-	}
-	b, err := json.Marshal(errJson)
-	require.NoError(t, err)
-
-	hasError, e := HandleGrpcResponseError(errJson, response, b, writer)
-	require.Equal(t, true, e == nil)
-	assert.Equal(t, true, hasError)
-	v, ok := writer.Header()["Foo"]
-	require.Equal(t, true, ok, "header not found")
-	require.Equal(t, 1, len(v), "wrong number of header values")
-	assert.Equal(t, "foo", v[0])
-	v, ok = writer.Header()["Bar"]
-	require.Equal(t, true, ok, "header not found")
-	require.Equal(t, 1, len(v), "wrong number of header values")
-	assert.Equal(t, "bar", v[0])
-	assert.Equal(t, 400, errJson.StatusCode())
-}
-
-func TestGrpcResponseIsEmpty(t *testing.T) {
-	t.Run("nil", func(t *testing.T) {
-		assert.Equal(t, true, GrpcResponseIsEmpty(nil))
-	})
-	t.Run("empty_slice", func(t *testing.T) {
-		assert.Equal(t, true, GrpcResponseIsEmpty(make([]byte, 0)))
-	})
-	t.Run("empty_brackets", func(t *testing.T) {
-		assert.Equal(t, true, GrpcResponseIsEmpty([]byte("{}")))
-	})
-	t.Run("non_empty", func(t *testing.T) {
-		assert.Equal(t, false, GrpcResponseIsEmpty([]byte("{\"foo\":\"bar\"})")))
-	})
-}
-
-func TestDeserializeGrpcResponseBodyIntoContainer(t *testing.T) {
-	t.Run("ok", func(t *testing.T) {
-		body, err := json.Marshal(defaultRequestContainer())
-		require.NoError(t, err)
-
-		container := &testRequestContainer{}
-		errJson := DeserializeGrpcResponseBodyIntoContainer(body, container)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "test string", container.TestString)
-	})
-
-	t.Run("error", func(t *testing.T) {
-		var bodyJson bytes.Buffer
-		bodyJson.Write([]byte("foo"))
-		errJson := DeserializeGrpcResponseBodyIntoContainer(bodyJson.Bytes(), &testRequestContainer{})
-		require.NotNil(t, errJson)
-		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not unmarshal response"))
-		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
-	})
-}
-
-func TestProcessMiddlewareResponseFields(t *testing.T) {
-	t.Run("Ok", func(t *testing.T) {
-		container := defaultResponseContainer()
-
-		errJson := ProcessMiddlewareResponseFields(container)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, "0x666f6f", container.TestHex)
-		assert.Equal(t, "0x", container.TestEmptyHex)
-		assert.Equal(t, "0x0000000000000000000000000000000000666F6f", container.TestAddress)
-		assert.Equal(t, "0x", container.TestEmptyAddress)
-		assert.Equal(t, "4196", container.TestUint256)
-		assert.Equal(t, "test enum", container.TestEnum)
-		assert.Equal(t, "1136214245", container.TestTime)
-	})
-
-	t.Run("error", func(t *testing.T) {
-		errJson := ProcessMiddlewareResponseFields("foo")
-		require.NotNil(t, errJson)
-		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not process response data"))
-		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
-	})
-}
-
-func TestSerializeMiddlewareResponseIntoJson(t *testing.T) {
-	container := defaultResponseContainer()
-	j, errJson := SerializeMiddlewareResponseIntoJson(container)
-	assert.Equal(t, true, errJson == nil)
-	cToDeserialize := &testResponseContainer{}
-	require.NoError(t, json.Unmarshal(j, cToDeserialize))
-	assert.Equal(t, "test string", cToDeserialize.TestString)
-}
-
-func TestWriteMiddlewareResponseHeadersAndBody(t *testing.T) {
-	t.Run("GET", func(t *testing.T) {
-		response := &http.Response{
-			Header: http.Header{
-				"Foo": []string{"foo"},
-				grpc.WithPrefix(grpc.HttpCodeMetadataKey): []string{"204"},
-				grpc.WithPrefix(api.VersionHeader):        []string{"capella"},
-			},
-		}
-		container := defaultResponseContainer()
-		responseJson, err := json.Marshal(container)
-		require.NoError(t, err)
-		writer := httptest.NewRecorder()
-		writer.Body = &bytes.Buffer{}
-
-		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
-		require.Equal(t, true, errJson == nil)
-		v, ok := writer.Header()["Foo"]
-		require.Equal(t, true, ok, "header not found")
-		require.Equal(t, 1, len(v), "wrong number of header values")
-		assert.Equal(t, "foo", v[0])
-		v, ok = writer.Header()["Content-Length"]
-		require.Equal(t, true, ok, "header not found")
-		require.Equal(t, 1, len(v), "wrong number of header values")
-		assert.Equal(t, "224", v[0])
-		v, ok = writer.Header()["Eth-Consensus-Version"]
-		require.Equal(t, true, ok, "header not found")
-		assert.Equal(t, "capella", v[0])
-		assert.Equal(t, 204, writer.Code)
-		assert.DeepEqual(t, responseJson, writer.Body.Bytes())
-	})
-
-	t.Run("GET_no_grpc_status_code_header", func(t *testing.T) {
-		response := &http.Response{
-			Header:     http.Header{},
-			StatusCode: 204,
-		}
-		container := defaultResponseContainer()
-		responseJson, err := json.Marshal(container)
-		require.NoError(t, err)
-		writer := httptest.NewRecorder()
-
-		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, 204, writer.Code)
-	})
-
-	t.Run("GET_invalid_status_code", func(t *testing.T) {
-		response := &http.Response{
-			Header: http.Header{"Grpc-Metadata-Eth-Consensus-Version": []string{"capella"}},
-		}
-
-		// Set invalid status code.
-		response.Header[grpc.WithPrefix(grpc.HttpCodeMetadataKey)] = []string{"invalid"}
-		response.Header[grpc.WithPrefix(api.VersionHeader)] = []string{"capella"}
-
-		container := defaultResponseContainer()
-		responseJson, err := json.Marshal(container)
-		require.NoError(t, err)
-		writer := httptest.NewRecorder()
-
-		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
-		require.Equal(t, false, errJson == nil)
-		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not parse status code"))
-		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
-	})
-
-	t.Run("POST", func(t *testing.T) {
-		response := &http.Response{
-			Header:     http.Header{},
-			StatusCode: 204,
-		}
-		container := defaultResponseContainer()
-		responseJson, err := json.Marshal(container)
-		require.NoError(t, err)
-		writer := httptest.NewRecorder()
-
-		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, 204, writer.Code)
-	})
-
-	t.Run("POST_with_response_body", func(t *testing.T) {
-		response := &http.Response{
-			Header:     http.Header{},
-			StatusCode: 204,
-		}
-		container := defaultResponseContainer()
-		responseJson, err := json.Marshal(container)
-		require.NoError(t, err)
-		writer := httptest.NewRecorder()
-		writer.Body = &bytes.Buffer{}
-
-		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, 204, writer.Code)
-		assert.DeepEqual(t, responseJson, writer.Body.Bytes())
-	})
-
-	t.Run("POST_with_empty_json_body", func(t *testing.T) {
-		response := &http.Response{
-			Header:     http.Header{},
-			StatusCode: 204,
-		}
-		responseJson, err := json.Marshal(struct{}{})
-		require.NoError(t, err)
-		writer := httptest.NewRecorder()
-		writer.Body = &bytes.Buffer{}
-
-		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
-		require.Equal(t, true, errJson == nil)
-		assert.Equal(t, 204, writer.Code)
-		assert.DeepEqual(t, []byte(nil), writer.Body.Bytes())
-		assert.Equal(t, "0", writer.Header()["Content-Length"][0])
-	})
-}
-
-func TestWriteError(t *testing.T) {
-	t.Run("ok", func(t *testing.T) {
-		responseHeader := http.Header{
-			grpc.WithPrefix(grpc.CustomErrorMetadataKey): []string{"{\"CustomField\":\"bar\"}"},
-		}
-		errJson := &testErrorJson{
-			Message: "foo",
-			Code:    500,
-		}
-		writer := httptest.NewRecorder()
-		writer.Body = &bytes.Buffer{}
-
-		WriteError(writer, errJson, responseHeader)
-		v, ok := writer.Header()["Content-Length"]
-		require.Equal(t, true, ok, "header not found")
-		require.Equal(t, 1, len(v), "wrong number of header values")
-		assert.Equal(t, "48", v[0])
-		v, ok = writer.Header()["Content-Type"]
-		require.Equal(t, true, ok, "header not found")
-		require.Equal(t, 1, len(v), "wrong number of header values")
-		assert.Equal(t, "application/json", v[0])
-		assert.Equal(t, 500, writer.Code)
-		eDeserialize := &testErrorJson{}
-		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), eDeserialize))
-		assert.Equal(t, "foo", eDeserialize.Message)
-		assert.Equal(t, 500, eDeserialize.Code)
-		assert.Equal(t, "bar", eDeserialize.CustomField)
-	})
-
-	t.Run("invalid_custom_error_header", func(t *testing.T) {
-		logHook := test.NewGlobal()
-
-		responseHeader := http.Header{
-			grpc.WithPrefix(grpc.CustomErrorMetadataKey): []string{"invalid"},
-		}
-
-		WriteError(httptest.NewRecorder(), &testErrorJson{}, responseHeader)
-		assert.LogsContain(t, logHook, "Could not unmarshal custom error message")
-	})
-}
--- a/api/gateway/apimiddleware/structs.go
+++ b/api/gateway/apimiddleware/structs.go
@@ -1,69 +0,0 @@
-package apimiddleware
-
-import (
-	"net/http"
-
-	"github.com/pkg/errors"
-)
-
-// ---------------
-// Error handling.
-// ---------------
-
-// ErrorJson describes common functionality of all JSON error representations.
-type ErrorJson interface {
-	StatusCode() int
-	SetCode(code int)
-	Msg() string
-	SetMsg(msg string)
-}
-
-// DefaultErrorJson is a JSON representation of a simple error value, containing only a message and an error code.
-type DefaultErrorJson struct {
-	Message string `json:"message"`
-	Code    int    `json:"code"`
-}
-
-// InternalServerErrorWithMessage returns a DefaultErrorJson with 500 code and a custom message.
-func InternalServerErrorWithMessage(err error, message string) *DefaultErrorJson {
-	e := errors.Wrapf(err, message)
-	return &DefaultErrorJson{
-		Message: e.Error(),
-		Code:    http.StatusInternalServerError,
-	}
-}
-
-// InternalServerError returns a DefaultErrorJson with 500 code.
-func InternalServerError(err error) *DefaultErrorJson {
-	return &DefaultErrorJson{
-		Message: err.Error(),
-		Code:    http.StatusInternalServerError,
-	}
-}
-
-func TimeoutError() *DefaultErrorJson {
-	return &DefaultErrorJson{
-		Message: "Request timeout",
-		Code:    http.StatusRequestTimeout,
-	}
-}
-
-// StatusCode returns the error's underlying error code.
-func (e *DefaultErrorJson) StatusCode() int {
-	return e.Code
-}
-
-// Msg returns the error's underlying message.
-func (e *DefaultErrorJson) Msg() string {
-	return e.Message
-}
-
-// SetCode sets the error's underlying error code.
-func (e *DefaultErrorJson) SetCode(code int) {
-	e.Code = code
-}
-
-// SetMsg sets the error's underlying message.
-func (e *DefaultErrorJson) SetMsg(msg string) {
-	e.Message = msg
-}
--- a/api/gateway/gateway.go
+++ b/api/gateway/gateway.go
@@ -11,9 +11,8 @@ import (
 	"github.com/gorilla/mux"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/v4/api/server"
 	"github.com/prysmaticlabs/prysm/v4/runtime"
-	"github.com/rs/cors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
@@ -34,7 +33,6 @@ type PbHandlerRegistration func(context.Context, *gwruntime.ServeMux, *grpc.Clie

 // MuxHandler is a function that implements the mux handler functionality.
 type MuxHandler func(
-	apiMiddlewareHandler *apimiddleware.ApiProxyMiddleware,
 	h http.HandlerFunc,
 	w http.ResponseWriter,
 	req *http.Request,
@@ -42,16 +40,15 @@ type MuxHandler func(

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

 // Gateway is the gRPC gateway to serve HTTP JSON traffic as a proxy and forward it to the gRPC server.
@@ -60,7 +57,6 @@ type Gateway struct {
 	conn         *grpc.ClientConn
 	server       *http.Server
 	cancel       context.CancelFunc
-	proxy        *apimiddleware.ApiProxyMiddleware
 	ctx          context.Context
 	startFailure error
 }
@@ -108,15 +104,11 @@ func (g *Gateway) Start() {
 		}
 	}

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

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

@@ -166,17 +158,6 @@ func (g *Gateway) Stop() error {
 	return nil
 }

-func (g *Gateway) corsMiddleware(h http.Handler) http.Handler {
-	c := cors.New(cors.Options{
-		AllowedOrigins:   g.cfg.allowedOrigins,
-		AllowedMethods:   []string{http.MethodPost, http.MethodGet, http.MethodDelete, http.MethodOptions},
-		AllowCredentials: true,
-		MaxAge:           600,
-		AllowedHeaders:   []string{"*"},
-	})
-	return c.Handler(h)
-}
-
 // dial the gRPC server.
 func (g *Gateway) dial(ctx context.Context, network, addr string) (*grpc.ClientConn, error) {
 	switch network {
@@ -229,13 +210,3 @@ func (g *Gateway) dialUnix(ctx context.Context, addr string) (*grpc.ClientConn,
 	}
 	return grpc.DialContext(ctx, addr, opts...)
 }
-
-func (g *Gateway) registerApiMiddleware() {
-	g.proxy = &apimiddleware.ApiProxyMiddleware{
-		GatewayAddress:  g.cfg.gatewayAddr,
-		EndpointCreator: g.cfg.apiMiddlewareEndpointFactory,
-		Timeout:         g.cfg.timeout,
-	}
-	log.Info("Starting API middleware")
-	g.proxy.Run(g.cfg.router)
-}
--- a/api/gateway/gateway_test.go
+++ b/api/gateway/gateway_test.go
@@ -10,7 +10,6 @@ import (
 	"testing"

 	"github.com/gorilla/mux"
-	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
 	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
@@ -18,36 +17,18 @@ import (
 	"github.com/urfave/cli/v2"
 )

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

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

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

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

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

-// WithApiMiddleware allows adding an API middleware proxy to the gateway.
-func WithApiMiddleware(endpointFactory apimiddleware.EndpointFactory) Option {
-	return func(g *Gateway) error {
-		g.cfg.apiMiddlewareEndpointFactory = endpointFactory
-		return nil
-	}
-}
-
 // WithTimeout allows changing the timeout value for API calls.
 func WithTimeout(seconds uint64) Option {
 	return func(g *Gateway) error {
--- a/api/headers.go
+++ b/api/headers.go
@@ -7,4 +7,6 @@ const (
 	ConsensusBlockValueHeader     = "Eth-Consensus-Block-Value"
 	JsonMediaType                 = "application/json"
 	OctetStreamMediaType          = "application/octet-stream"
+	EventStreamMediaType          = "text/event-stream"
+	KeepAlive                     = "keep-alive"
 )
--- a/api/server/BUILD.bazel
+++ b/api/server/BUILD.bazel
@@ -3,16 +3,22 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = [
+        "error.go",
        "middleware.go",
        "util.go",
    ],
    importpath = "github.com/prysmaticlabs/prysm/v4/api/server",
    visibility = ["//visibility:public"],
+    deps = [
+        "@com_github_gorilla_mux//:go_default_library",
+        "@com_github_rs_cors//:go_default_library",
+    ],
 )

 go_test(
    name = "go_default_test",
    srcs = [
+        "error_test.go",
        "middleware_test.go",
        "util_test.go",
    ],
--- a/api/server/error.go
+++ b/api/server/error.go
@@ -0,0 +1,45 @@
+package server
+
+import (
+	"fmt"
+	"strings"
+)
+
+// DecodeError represents an error resulting from trying to decode an HTTP request.
+// It tracks the full field name for which decoding failed.
+type DecodeError struct {
+	path []string
+	err  error
+}
+
+// NewDecodeError wraps an error (either the initial decoding error or another DecodeError).
+// The current field that failed decoding must be passed in.
+func NewDecodeError(err error, field string) *DecodeError {
+	de, ok := err.(*DecodeError)
+	if ok {
+		return &DecodeError{path: append([]string{field}, de.path...), err: de.err}
+	}
+	return &DecodeError{path: []string{field}, err: err}
+}
+
+// Error returns the formatted error message which contains the full field name and the actual decoding error.
+func (e *DecodeError) Error() string {
+	return fmt.Sprintf("could not decode %s: %s", strings.Join(e.path, "."), e.err.Error())
+}
+
+// IndexedVerificationFailureError wraps a collection of verification failures.
+type IndexedVerificationFailureError struct {
+	Message  string                        `json:"message"`
+	Code     int                           `json:"code"`
+	Failures []*IndexedVerificationFailure `json:"failures"`
+}
+
+func (e *IndexedVerificationFailureError) StatusCode() int {
+	return e.Code
+}
+
+// IndexedVerificationFailure represents an issue when verifying a single indexed object e.g. an item in an array.
+type IndexedVerificationFailure struct {
+	Index   int    `json:"index"`
+	Message string `json:"message"`
+}
--- a/api/server/error_test.go
+++ b/api/server/error_test.go
@@ -0,0 +1,16 @@
+package server
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+)
+
+func TestDecodeError(t *testing.T) {
+	e := errors.New("not a number")
+	de := NewDecodeError(e, "Z")
+	de = NewDecodeError(de, "Y")
+	de = NewDecodeError(de, "X")
+	assert.Equal(t, "could not decode X.Y.Z: not a number", de.Error())
+}
--- a/api/server/middleware.go
+++ b/api/server/middleware.go
@@ -2,8 +2,12 @@ package server

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

+// NormalizeQueryValuesHandler normalizes an input query of "key=value1,value2,value3" to "key=value1&key=value2&key=value3"
 func NormalizeQueryValuesHandler(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		query := r.URL.Query()
@@ -13,3 +17,16 @@ func NormalizeQueryValuesHandler(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
+
+// CorsHandler sets the cors settings on api endpoints
+func CorsHandler(allowOrigins []string) mux.MiddlewareFunc {
+	c := cors.New(cors.Options{
+		AllowedOrigins:   allowOrigins,
+		AllowedMethods:   []string{http.MethodPost, http.MethodGet, http.MethodDelete, http.MethodOptions},
+		AllowCredentials: true,
+		MaxAge:           600,
+		AllowedHeaders:   []string{"*"},
+	})
+
+	return c.Handler
+}
--- a/api/server/structs/BUILD.bazel
+++ b/api/server/structs/BUILD.bazel
@@ -0,0 +1,50 @@
+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/v4/api/server/structs",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//api/server:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//consensus-types/validator:go_default_library",
+        "//container/slice:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//math:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["conversions_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+    ],
+)
--- a/api/server/structs/block.go
+++ b/api/server/structs/block.go
@@ -0,0 +1,353 @@
+package structs
+
+type SignedBeaconBlock struct {
+	Message   *BeaconBlock `json:"message"`
+	Signature string       `json:"signature"`
+}
+
+type BeaconBlock struct {
+	Slot          string           `json:"slot"`
+	ProposerIndex string           `json:"proposer_index"`
+	ParentRoot    string           `json:"parent_root"`
+	StateRoot     string           `json:"state_root"`
+	Body          *BeaconBlockBody `json:"body"`
+}
+
+type BeaconBlockBody struct {
+	RandaoReveal      string                 `json:"randao_reveal"`
+	Eth1Data          *Eth1Data              `json:"eth1_data"`
+	Graffiti          string                 `json:"graffiti"`
+	ProposerSlashings []*ProposerSlashing    `json:"proposer_slashings"`
+	AttesterSlashings []*AttesterSlashing    `json:"attester_slashings"`
+	Attestations      []*Attestation         `json:"attestations"`
+	Deposits          []*Deposit             `json:"deposits"`
+	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
+}
+
+type SignedBeaconBlockAltair struct {
+	Message   *BeaconBlockAltair `json:"message"`
+	Signature string             `json:"signature"`
+}
+
+type BeaconBlockAltair struct {
+	Slot          string                 `json:"slot"`
+	ProposerIndex string                 `json:"proposer_index"`
+	ParentRoot    string                 `json:"parent_root"`
+	StateRoot     string                 `json:"state_root"`
+	Body          *BeaconBlockBodyAltair `json:"body"`
+}
+
+type BeaconBlockBodyAltair struct {
+	RandaoReveal      string                 `json:"randao_reveal"`
+	Eth1Data          *Eth1Data              `json:"eth1_data"`
+	Graffiti          string                 `json:"graffiti"`
+	ProposerSlashings []*ProposerSlashing    `json:"proposer_slashings"`
+	AttesterSlashings []*AttesterSlashing    `json:"attester_slashings"`
+	Attestations      []*Attestation         `json:"attestations"`
+	Deposits          []*Deposit             `json:"deposits"`
+	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
+	SyncAggregate     *SyncAggregate         `json:"sync_aggregate"`
+}
+
+type SignedBeaconBlockBellatrix struct {
+	Message   *BeaconBlockBellatrix `json:"message"`
+	Signature string                `json:"signature"`
+}
+
+type BeaconBlockBellatrix struct {
+	Slot          string                    `json:"slot"`
+	ProposerIndex string                    `json:"proposer_index"`
+	ParentRoot    string                    `json:"parent_root"`
+	StateRoot     string                    `json:"state_root"`
+	Body          *BeaconBlockBodyBellatrix `json:"body"`
+}
+
+type BeaconBlockBodyBellatrix struct {
+	RandaoReveal      string                 `json:"randao_reveal"`
+	Eth1Data          *Eth1Data              `json:"eth1_data"`
+	Graffiti          string                 `json:"graffiti"`
+	ProposerSlashings []*ProposerSlashing    `json:"proposer_slashings"`
+	AttesterSlashings []*AttesterSlashing    `json:"attester_slashings"`
+	Attestations      []*Attestation         `json:"attestations"`
+	Deposits          []*Deposit             `json:"deposits"`
+	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
+	SyncAggregate     *SyncAggregate         `json:"sync_aggregate"`
+	ExecutionPayload  *ExecutionPayload      `json:"execution_payload"`
+}
+
+type SignedBlindedBeaconBlockBellatrix struct {
+	Message   *BlindedBeaconBlockBellatrix `json:"message"`
+	Signature string                       `json:"signature"`
+}
+
+type BlindedBeaconBlockBellatrix struct {
+	Slot          string                           `json:"slot"`
+	ProposerIndex string                           `json:"proposer_index"`
+	ParentRoot    string                           `json:"parent_root"`
+	StateRoot     string                           `json:"state_root"`
+	Body          *BlindedBeaconBlockBodyBellatrix `json:"body"`
+}
+
+type BlindedBeaconBlockBodyBellatrix struct {
+	RandaoReveal           string                  `json:"randao_reveal"`
+	Eth1Data               *Eth1Data               `json:"eth1_data"`
+	Graffiti               string                  `json:"graffiti"`
+	ProposerSlashings      []*ProposerSlashing     `json:"proposer_slashings"`
+	AttesterSlashings      []*AttesterSlashing     `json:"attester_slashings"`
+	Attestations           []*Attestation          `json:"attestations"`
+	Deposits               []*Deposit              `json:"deposits"`
+	VoluntaryExits         []*SignedVoluntaryExit  `json:"voluntary_exits"`
+	SyncAggregate          *SyncAggregate          `json:"sync_aggregate"`
+	ExecutionPayloadHeader *ExecutionPayloadHeader `json:"execution_payload_header"`
+}
+
+type SignedBeaconBlockCapella struct {
+	Message   *BeaconBlockCapella `json:"message"`
+	Signature string              `json:"signature"`
+}
+
+type BeaconBlockCapella struct {
+	Slot          string                  `json:"slot"`
+	ProposerIndex string                  `json:"proposer_index"`
+	ParentRoot    string                  `json:"parent_root"`
+	StateRoot     string                  `json:"state_root"`
+	Body          *BeaconBlockBodyCapella `json:"body"`
+}
+
+type BeaconBlockBodyCapella struct {
+	RandaoReveal          string                        `json:"randao_reveal"`
+	Eth1Data              *Eth1Data                     `json:"eth1_data"`
+	Graffiti              string                        `json:"graffiti"`
+	ProposerSlashings     []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings     []*AttesterSlashing           `json:"attester_slashings"`
+	Attestations          []*Attestation                `json:"attestations"`
+	Deposits              []*Deposit                    `json:"deposits"`
+	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayload      *ExecutionPayloadCapella      `json:"execution_payload"`
+	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+}
+
+type SignedBlindedBeaconBlockCapella struct {
+	Message   *BlindedBeaconBlockCapella `json:"message"`
+	Signature string                     `json:"signature"`
+}
+
+type BlindedBeaconBlockCapella struct {
+	Slot          string                         `json:"slot"`
+	ProposerIndex string                         `json:"proposer_index"`
+	ParentRoot    string                         `json:"parent_root"`
+	StateRoot     string                         `json:"state_root"`
+	Body          *BlindedBeaconBlockBodyCapella `json:"body"`
+}
+
+type BlindedBeaconBlockBodyCapella struct {
+	RandaoReveal           string                         `json:"randao_reveal"`
+	Eth1Data               *Eth1Data                      `json:"eth1_data"`
+	Graffiti               string                         `json:"graffiti"`
+	ProposerSlashings      []*ProposerSlashing            `json:"proposer_slashings"`
+	AttesterSlashings      []*AttesterSlashing            `json:"attester_slashings"`
+	Attestations           []*Attestation                 `json:"attestations"`
+	Deposits               []*Deposit                     `json:"deposits"`
+	VoluntaryExits         []*SignedVoluntaryExit         `json:"voluntary_exits"`
+	SyncAggregate          *SyncAggregate                 `json:"sync_aggregate"`
+	ExecutionPayloadHeader *ExecutionPayloadHeaderCapella `json:"execution_payload_header"`
+	BLSToExecutionChanges  []*SignedBLSToExecutionChange  `json:"bls_to_execution_changes"`
+}
+
+type SignedBeaconBlockContentsDeneb struct {
+	SignedBlock *SignedBeaconBlockDeneb `json:"signed_block"`
+	KzgProofs   []string                `json:"kzg_proofs"`
+	Blobs       []string                `json:"blobs"`
+}
+
+type BeaconBlockContentsDeneb struct {
+	Block     *BeaconBlockDeneb `json:"block"`
+	KzgProofs []string          `json:"kzg_proofs"`
+	Blobs     []string          `json:"blobs"`
+}
+
+type SignedBeaconBlockDeneb struct {
+	Message   *BeaconBlockDeneb `json:"message"`
+	Signature string            `json:"signature"`
+}
+
+type BeaconBlockDeneb struct {
+	Slot          string                `json:"slot"`
+	ProposerIndex string                `json:"proposer_index"`
+	ParentRoot    string                `json:"parent_root"`
+	StateRoot     string                `json:"state_root"`
+	Body          *BeaconBlockBodyDeneb `json:"body"`
+}
+
+type BeaconBlockBodyDeneb struct {
+	RandaoReveal          string                        `json:"randao_reveal"`
+	Eth1Data              *Eth1Data                     `json:"eth1_data"`
+	Graffiti              string                        `json:"graffiti"`
+	ProposerSlashings     []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings     []*AttesterSlashing           `json:"attester_slashings"`
+	Attestations          []*Attestation                `json:"attestations"`
+	Deposits              []*Deposit                    `json:"deposits"`
+	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayload      *ExecutionPayloadDeneb        `json:"execution_payload"`
+	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+	BlobKzgCommitments    []string                      `json:"blob_kzg_commitments"`
+}
+
+type BlindedBeaconBlockDeneb struct {
+	Slot          string                       `json:"slot"`
+	ProposerIndex string                       `json:"proposer_index"`
+	ParentRoot    string                       `json:"parent_root"`
+	StateRoot     string                       `json:"state_root"`
+	Body          *BlindedBeaconBlockBodyDeneb `json:"body"`
+}
+
+type SignedBlindedBeaconBlockDeneb struct {
+	Message   *BlindedBeaconBlockDeneb `json:"message"`
+	Signature string                   `json:"signature"`
+}
+
+type BlindedBeaconBlockBodyDeneb struct {
+	RandaoReveal           string                        `json:"randao_reveal"`
+	Eth1Data               *Eth1Data                     `json:"eth1_data"`
+	Graffiti               string                        `json:"graffiti"`
+	ProposerSlashings      []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings      []*AttesterSlashing           `json:"attester_slashings"`
+	Attestations           []*Attestation                `json:"attestations"`
+	Deposits               []*Deposit                    `json:"deposits"`
+	VoluntaryExits         []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate          *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayloadHeader *ExecutionPayloadHeaderDeneb  `json:"execution_payload_header"`
+	BLSToExecutionChanges  []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
+}
+
+type SignedBeaconBlockHeaderContainer struct {
+	Header    *SignedBeaconBlockHeader `json:"header"`
+	Root      string                   `json:"root"`
+	Canonical bool                     `json:"canonical"`
+}
+
+type SignedBeaconBlockHeader struct {
+	Message   *BeaconBlockHeader `json:"message"`
+	Signature string             `json:"signature"`
+}
+
+type BeaconBlockHeader struct {
+	Slot          string `json:"slot"`
+	ProposerIndex string `json:"proposer_index"`
+	ParentRoot    string `json:"parent_root"`
+	StateRoot     string `json:"state_root"`
+	BodyRoot      string `json:"body_root"`
+}
+
+type ExecutionPayload struct {
+	ParentHash    string   `json:"parent_hash"`
+	FeeRecipient  string   `json:"fee_recipient"`
+	StateRoot     string   `json:"state_root"`
+	ReceiptsRoot  string   `json:"receipts_root"`
+	LogsBloom     string   `json:"logs_bloom"`
+	PrevRandao    string   `json:"prev_randao"`
+	BlockNumber   string   `json:"block_number"`
+	GasLimit      string   `json:"gas_limit"`
+	GasUsed       string   `json:"gas_used"`
+	Timestamp     string   `json:"timestamp"`
+	ExtraData     string   `json:"extra_data"`
+	BaseFeePerGas string   `json:"base_fee_per_gas"`
+	BlockHash     string   `json:"block_hash"`
+	Transactions  []string `json:"transactions"`
+}
+
+type ExecutionPayloadHeader struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+}
+
+type ExecutionPayloadCapella struct {
+	ParentHash    string        `json:"parent_hash"`
+	FeeRecipient  string        `json:"fee_recipient"`
+	StateRoot     string        `json:"state_root"`
+	ReceiptsRoot  string        `json:"receipts_root"`
+	LogsBloom     string        `json:"logs_bloom"`
+	PrevRandao    string        `json:"prev_randao"`
+	BlockNumber   string        `json:"block_number"`
+	GasLimit      string        `json:"gas_limit"`
+	GasUsed       string        `json:"gas_used"`
+	Timestamp     string        `json:"timestamp"`
+	ExtraData     string        `json:"extra_data"`
+	BaseFeePerGas string        `json:"base_fee_per_gas"`
+	BlockHash     string        `json:"block_hash"`
+	Transactions  []string      `json:"transactions"`
+	Withdrawals   []*Withdrawal `json:"withdrawals"`
+}
+
+type ExecutionPayloadHeaderCapella struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+	WithdrawalsRoot  string `json:"withdrawals_root"`
+}
+
+type ExecutionPayloadDeneb struct {
+	ParentHash    string        `json:"parent_hash"`
+	FeeRecipient  string        `json:"fee_recipient"`
+	StateRoot     string        `json:"state_root"`
+	ReceiptsRoot  string        `json:"receipts_root"`
+	LogsBloom     string        `json:"logs_bloom"`
+	PrevRandao    string        `json:"prev_randao"`
+	BlockNumber   string        `json:"block_number"`
+	GasLimit      string        `json:"gas_limit"`
+	GasUsed       string        `json:"gas_used"`
+	Timestamp     string        `json:"timestamp"`
+	ExtraData     string        `json:"extra_data"`
+	BaseFeePerGas string        `json:"base_fee_per_gas"`
+	BlockHash     string        `json:"block_hash"`
+	Transactions  []string      `json:"transactions"`
+	Withdrawals   []*Withdrawal `json:"withdrawals"`
+	BlobGasUsed   string        `json:"blob_gas_used"`
+	ExcessBlobGas string        `json:"excess_blob_gas"`
+}
+
+type ExecutionPayloadHeaderDeneb struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+	WithdrawalsRoot  string `json:"withdrawals_root"`
+	BlobGasUsed      string `json:"blob_gas_used"`
+	ExcessBlobGas    string `json:"excess_blob_gas"`
+}
--- a/api/server/structs/conversions.go
+++ b/api/server/structs/conversions.go
--- a/api/server/structs/conversions_block.go
+++ b/api/server/structs/conversions_block.go
--- a/api/server/structs/conversions_state.go
+++ b/api/server/structs/conversions_state.go
@@ -0,0 +1,595 @@
+package structs
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	beaconState "github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+)
+
+var errPayloadHeaderNotFound = errors.New("expected payload header not found")
+
+func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevAtts, err := st.PreviousEpochAttestations()
+	if err != nil {
+		return nil, err
+	}
+	prevAtts := make([]*PendingAttestation, len(srcPrevAtts))
+	for i, a := range srcPrevAtts {
+		prevAtts[i] = PendingAttestationFromConsensus(a)
+	}
+	srcCurrAtts, err := st.CurrentEpochAttestations()
+	if err != nil {
+		return nil, err
+	}
+	currAtts := make([]*PendingAttestation, len(srcCurrAtts))
+	for i, a := range srcCurrAtts {
+		currAtts[i] = PendingAttestationFromConsensus(a)
+	}
+
+	return &BeaconState{
+		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:       hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                        fmt.Sprintf("%d", st.Slot()),
+		Fork:                        ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:           BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                  br,
+		StateRoots:                  sr,
+		HistoricalRoots:             hr,
+		Eth1Data:                    Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:               votes,
+		Eth1DepositIndex:            fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                  vals,
+		Balances:                    bals,
+		RandaoMixes:                 rm,
+		Slashings:                   slashings,
+		PreviousEpochAttestations:   prevAtts,
+		CurrentEpochAttestations:    currAtts,
+		JustificationBits:           hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint: CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:  CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:         CheckpointFromConsensus(st.FinalizedCheckpoint()),
+	}, nil
+}
+
+func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAltair, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevPart, err := st.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	prevPart := make([]string, len(srcPrevPart))
+	for i, p := range srcPrevPart {
+		prevPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcCurrPart, err := st.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currPart := make([]string, len(srcCurrPart))
+	for i, p := range srcCurrPart {
+		currPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcIs, err := st.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	is := make([]string, len(srcIs))
+	for i, s := range srcIs {
+		is[i] = fmt.Sprintf("%d", s)
+	}
+	currSc, err := st.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSc, err := st.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+
+	return &BeaconStateAltair{
+		GenesisTime:                 fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:       hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                        fmt.Sprintf("%d", st.Slot()),
+		Fork:                        ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:           BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                  br,
+		StateRoots:                  sr,
+		HistoricalRoots:             hr,
+		Eth1Data:                    Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:               votes,
+		Eth1DepositIndex:            fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                  vals,
+		Balances:                    bals,
+		RandaoMixes:                 rm,
+		Slashings:                   slashings,
+		PreviousEpochParticipation:  prevPart,
+		CurrentEpochParticipation:   currPart,
+		JustificationBits:           hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint: CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:  CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:         CheckpointFromConsensus(st.FinalizedCheckpoint()),
+		InactivityScores:            is,
+		CurrentSyncCommittee:        SyncCommitteeFromConsensus(currSc),
+		NextSyncCommittee:           SyncCommitteeFromConsensus(nextSc),
+	}, nil
+}
+
+func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconStateBellatrix, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevPart, err := st.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	prevPart := make([]string, len(srcPrevPart))
+	for i, p := range srcPrevPart {
+		prevPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcCurrPart, err := st.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currPart := make([]string, len(srcCurrPart))
+	for i, p := range srcCurrPart {
+		currPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcIs, err := st.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	is := make([]string, len(srcIs))
+	for i, s := range srcIs {
+		is[i] = fmt.Sprintf("%d", s)
+	}
+	currSc, err := st.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSc, err := st.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	execData, err := st.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeader)
+	if !ok {
+		return nil, errPayloadHeaderNotFound
+	}
+	payload, err := ExecutionPayloadHeaderFromConsensus(srcPayload)
+	if err != nil {
+		return nil, err
+	}
+
+	return &BeaconStateBellatrix{
+		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                         fmt.Sprintf("%d", st.Slot()),
+		Fork:                         ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:            BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                   br,
+		StateRoots:                   sr,
+		HistoricalRoots:              hr,
+		Eth1Data:                     Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:                votes,
+		Eth1DepositIndex:             fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                   vals,
+		Balances:                     bals,
+		RandaoMixes:                  rm,
+		Slashings:                    slashings,
+		PreviousEpochParticipation:   prevPart,
+		CurrentEpochParticipation:    currPart,
+		JustificationBits:            hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint:  CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:   CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:          CheckpointFromConsensus(st.FinalizedCheckpoint()),
+		InactivityScores:             is,
+		CurrentSyncCommittee:         SyncCommitteeFromConsensus(currSc),
+		NextSyncCommittee:            SyncCommitteeFromConsensus(nextSc),
+		LatestExecutionPayloadHeader: payload,
+	}, nil
+}
+
+func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCapella, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevPart, err := st.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	prevPart := make([]string, len(srcPrevPart))
+	for i, p := range srcPrevPart {
+		prevPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcCurrPart, err := st.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currPart := make([]string, len(srcCurrPart))
+	for i, p := range srcCurrPart {
+		currPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcIs, err := st.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	is := make([]string, len(srcIs))
+	for i, s := range srcIs {
+		is[i] = fmt.Sprintf("%d", s)
+	}
+	currSc, err := st.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSc, err := st.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	execData, err := st.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeaderCapella)
+	if !ok {
+		return nil, errPayloadHeaderNotFound
+	}
+	payload, err := ExecutionPayloadHeaderCapellaFromConsensus(srcPayload)
+	if err != nil {
+		return nil, err
+	}
+	srcHs, err := st.HistoricalSummaries()
+	if err != nil {
+		return nil, err
+	}
+	hs := make([]*HistoricalSummary, len(srcHs))
+	for i, s := range srcHs {
+		hs[i] = HistoricalSummaryFromConsensus(s)
+	}
+	nwi, err := st.NextWithdrawalIndex()
+	if err != nil {
+		return nil, err
+	}
+	nwvi, err := st.NextWithdrawalValidatorIndex()
+	if err != nil {
+		return nil, err
+	}
+
+	return &BeaconStateCapella{
+		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                         fmt.Sprintf("%d", st.Slot()),
+		Fork:                         ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:            BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                   br,
+		StateRoots:                   sr,
+		HistoricalRoots:              hr,
+		Eth1Data:                     Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:                votes,
+		Eth1DepositIndex:             fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                   vals,
+		Balances:                     bals,
+		RandaoMixes:                  rm,
+		Slashings:                    slashings,
+		PreviousEpochParticipation:   prevPart,
+		CurrentEpochParticipation:    currPart,
+		JustificationBits:            hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint:  CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:   CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:          CheckpointFromConsensus(st.FinalizedCheckpoint()),
+		InactivityScores:             is,
+		CurrentSyncCommittee:         SyncCommitteeFromConsensus(currSc),
+		NextSyncCommittee:            SyncCommitteeFromConsensus(nextSc),
+		LatestExecutionPayloadHeader: payload,
+		NextWithdrawalIndex:          fmt.Sprintf("%d", nwi),
+		NextWithdrawalValidatorIndex: fmt.Sprintf("%d", nwvi),
+		HistoricalSummaries:          hs,
+	}, nil
+}
+
+func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDeneb, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevPart, err := st.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	prevPart := make([]string, len(srcPrevPart))
+	for i, p := range srcPrevPart {
+		prevPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcCurrPart, err := st.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currPart := make([]string, len(srcCurrPart))
+	for i, p := range srcCurrPart {
+		currPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcIs, err := st.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	is := make([]string, len(srcIs))
+	for i, s := range srcIs {
+		is[i] = fmt.Sprintf("%d", s)
+	}
+	currSc, err := st.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSc, err := st.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	execData, err := st.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+	if !ok {
+		return nil, errPayloadHeaderNotFound
+	}
+	payload, err := ExecutionPayloadHeaderDenebFromConsensus(srcPayload)
+	if err != nil {
+		return nil, err
+	}
+	srcHs, err := st.HistoricalSummaries()
+	if err != nil {
+		return nil, err
+	}
+	hs := make([]*HistoricalSummary, len(srcHs))
+	for i, s := range srcHs {
+		hs[i] = HistoricalSummaryFromConsensus(s)
+	}
+	nwi, err := st.NextWithdrawalIndex()
+	if err != nil {
+		return nil, err
+	}
+	nwvi, err := st.NextWithdrawalValidatorIndex()
+	if err != nil {
+		return nil, err
+	}
+
+	return &BeaconStateDeneb{
+		GenesisTime:                  fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:        hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                         fmt.Sprintf("%d", st.Slot()),
+		Fork:                         ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:            BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                   br,
+		StateRoots:                   sr,
+		HistoricalRoots:              hr,
+		Eth1Data:                     Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:                votes,
+		Eth1DepositIndex:             fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                   vals,
+		Balances:                     bals,
+		RandaoMixes:                  rm,
+		Slashings:                    slashings,
+		PreviousEpochParticipation:   prevPart,
+		CurrentEpochParticipation:    currPart,
+		JustificationBits:            hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint:  CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:   CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:          CheckpointFromConsensus(st.FinalizedCheckpoint()),
+		InactivityScores:             is,
+		CurrentSyncCommittee:         SyncCommitteeFromConsensus(currSc),
+		NextSyncCommittee:            SyncCommitteeFromConsensus(nextSc),
+		LatestExecutionPayloadHeader: payload,
+		NextWithdrawalIndex:          fmt.Sprintf("%d", nwi),
+		NextWithdrawalValidatorIndex: fmt.Sprintf("%d", nwvi),
+		HistoricalSummaries:          hs,
+	}, nil
+}
--- a/api/server/structs/conversions_test.go
+++ b/api/server/structs/conversions_test.go
@@ -0,0 +1,26 @@
+package structs
+
+import (
+	"testing"
+
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/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_beacon.go
+++ b/api/server/structs/endpoints_beacon.go
@@ -1,45 +1,45 @@
-package beacon
+package structs

 import (
 	"encoding/json"
-
-	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
 )

 type BlockRootResponse struct {
-	Data *struct {
-		Root string `json:"root"`
-	} `json:"data"`
-	ExecutionOptimistic bool `json:"execution_optimistic"`
-	Finalized           bool `json:"finalized"`
+	Data                *BlockRoot `json:"data"`
+	ExecutionOptimistic bool       `json:"execution_optimistic"`
+	Finalized           bool       `json:"finalized"`
+}
+
+type BlockRoot struct {
+	Root string `json:"root"`
 }

 type GetCommitteesResponse struct {
-	Data                []*shared.Committee `json:"data"`
-	ExecutionOptimistic bool                `json:"execution_optimistic"`
-	Finalized           bool                `json:"finalized"`
+	Data                []*Committee `json:"data"`
+	ExecutionOptimistic bool         `json:"execution_optimistic"`
+	Finalized           bool         `json:"finalized"`
 }

 type ListAttestationsResponse struct {
-	Data []*shared.Attestation `json:"data"`
+	Data []*Attestation `json:"data"`
 }

 type SubmitAttestationsRequest struct {
-	Data []*shared.Attestation `json:"data"`
+	Data []*Attestation `json:"data"`
 }

 type ListVoluntaryExitsResponse struct {
-	Data []*shared.SignedVoluntaryExit `json:"data"`
+	Data []*SignedVoluntaryExit `json:"data"`
 }

 type SubmitSyncCommitteeSignaturesRequest struct {
-	Data []*shared.SyncCommitteeMessage `json:"data"`
+	Data []*SyncCommitteeMessage `json:"data"`
 }

 type GetStateForkResponse struct {
-	Data                *shared.Fork `json:"data"`
-	ExecutionOptimistic bool         `json:"execution_optimistic"`
-	Finalized           bool         `json:"finalized"`
+	Data                *Fork `json:"data"`
+	ExecutionOptimistic bool  `json:"execution_optimistic"`
+	Finalized           bool  `json:"finalized"`
 }

 type GetFinalityCheckpointsResponse struct {
@@ -49,9 +49,9 @@ type GetFinalityCheckpointsResponse struct {
 }

 type FinalityCheckpoints struct {
-	PreviousJustified *shared.Checkpoint `json:"previous_justified"`
-	CurrentJustified  *shared.Checkpoint `json:"current_justified"`
-	Finalized         *shared.Checkpoint `json:"finalized"`
+	PreviousJustified *Checkpoint `json:"previous_justified"`
+	CurrentJustified  *Checkpoint `json:"current_justified"`
+	Finalized         *Checkpoint `json:"finalized"`
 }

 type GetGenesisResponse struct {
@@ -65,15 +65,15 @@ type Genesis struct {
 }

 type GetBlockHeadersResponse struct {
-	Data                []*shared.SignedBeaconBlockHeaderContainer `json:"data"`
-	ExecutionOptimistic bool                                       `json:"execution_optimistic"`
-	Finalized           bool                                       `json:"finalized"`
+	Data                []*SignedBeaconBlockHeaderContainer `json:"data"`
+	ExecutionOptimistic bool                                `json:"execution_optimistic"`
+	Finalized           bool                                `json:"finalized"`
 }

 type GetBlockHeaderResponse struct {
-	ExecutionOptimistic bool                                     `json:"execution_optimistic"`
-	Finalized           bool                                     `json:"finalized"`
-	Data                *shared.SignedBeaconBlockHeaderContainer `json:"data"`
+	ExecutionOptimistic bool                              `json:"execution_optimistic"`
+	Finalized           bool                              `json:"finalized"`
+	Data                *SignedBeaconBlockHeaderContainer `json:"data"`
 }

 type GetValidatorsRequest struct {
@@ -106,17 +106,6 @@ type ValidatorContainer struct {
 	Validator *Validator `json:"validator"`
 }

-type Validator struct {
-	Pubkey                     string `json:"pubkey"`
-	WithdrawalCredentials      string `json:"withdrawal_credentials"`
-	EffectiveBalance           string `json:"effective_balance"`
-	Slashed                    bool   `json:"slashed"`
-	ActivationEligibilityEpoch string `json:"activation_eligibility_epoch"`
-	ActivationEpoch            string `json:"activation_epoch"`
-	ExitEpoch                  string `json:"exit_epoch"`
-	WithdrawableEpoch          string `json:"withdrawable_epoch"`
-}
-
 type ValidatorBalance struct {
 	Index   string `json:"index"`
 	Balance string `json:"balance"`
@@ -139,9 +128,9 @@ type SignedBlock struct {
 }

 type GetBlockAttestationsResponse struct {
-	ExecutionOptimistic bool                  `json:"execution_optimistic"`
-	Finalized           bool                  `json:"finalized"`
-	Data                []*shared.Attestation `json:"data"`
+	ExecutionOptimistic bool           `json:"execution_optimistic"`
+	Finalized           bool           `json:"finalized"`
+	Data                []*Attestation `json:"data"`
 }

 type GetStateRootResponse struct {
@@ -176,13 +165,34 @@ type SyncCommitteeValidators struct {
 }

 type BLSToExecutionChangesPoolResponse struct {
-	Data []*shared.SignedBLSToExecutionChange `json:"data"`
+	Data []*SignedBLSToExecutionChange `json:"data"`
 }

 type GetAttesterSlashingsResponse struct {
-	Data []*shared.AttesterSlashing `json:"data"`
+	Data []*AttesterSlashing `json:"data"`
 }

 type GetProposerSlashingsResponse struct {
-	Data []*shared.ProposerSlashing `json:"data"`
+	Data []*ProposerSlashing `json:"data"`
+}
+
+type GetWeakSubjectivityResponse struct {
+	Data *WeakSubjectivityData `json:"data"`
+}
+
+type WeakSubjectivityData struct {
+	WsCheckpoint *Checkpoint `json:"ws_checkpoint"`
+	StateRoot    string      `json:"state_root"`
+}
+
+type GetDepositSnapshotResponse struct {
+	Data *DepositSnapshot `json:"data"`
+}
+
+type DepositSnapshot struct {
+	Finalized            []string `json:"finalized"`
+	DepositRoot          string   `json:"deposit_root"`
+	DepositCount         string   `json:"deposit_count"`
+	ExecutionBlockHash   string   `json:"execution_block_hash"`
+	ExecutionBlockHeight string   `json:"execution_block_height"`
 }
--- a/api/server/structs/endpoints_blob.go
+++ b/api/server/structs/endpoints_blob.go
@@ -0,0 +1,14 @@
+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_builder.go
+++ b/api/server/structs/endpoints_builder.go
@@ -1,4 +1,4 @@
-package builder
+package structs

 type ExpectedWithdrawalsResponse struct {
 	Data                []*ExpectedWithdrawal `json:"data"`
--- a/api/server/structs/endpoints_config.go
+++ b/api/server/structs/endpoints_config.go
@@ -1,6 +1,4 @@
-package config
-
-import "github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+package structs

 type GetDepositContractResponse struct {
 	Data *DepositContractData `json:"data"`
@@ -12,7 +10,7 @@ type DepositContractData struct {
 }

 type GetForkScheduleResponse struct {
-	Data []*shared.Fork `json:"data"`
+	Data []*Fork `json:"data"`
 }

 type GetSpecResponse struct {
--- a/api/server/structs/endpoints_debug.go
+++ b/api/server/structs/endpoints_debug.go
@@ -0,0 +1,57 @@
+package structs
+
+import (
+	"encoding/json"
+)
+
+type GetBeaconStateV2Response struct {
+	Version             string          `json:"version"`
+	ExecutionOptimistic bool            `json:"execution_optimistic"`
+	Finalized           bool            `json:"finalized"`
+	Data                json.RawMessage `json:"data"` // represents the state values based on the version
+}
+
+type GetForkChoiceHeadsV2Response struct {
+	Data []*ForkChoiceHead `json:"data"`
+}
+
+type ForkChoiceHead struct {
+	Root                string `json:"root"`
+	Slot                string `json:"slot"`
+	ExecutionOptimistic bool   `json:"execution_optimistic"`
+}
+
+type GetForkChoiceDumpResponse struct {
+	JustifiedCheckpoint *Checkpoint              `json:"justified_checkpoint"`
+	FinalizedCheckpoint *Checkpoint              `json:"finalized_checkpoint"`
+	ForkChoiceNodes     []*ForkChoiceNode        `json:"fork_choice_nodes"`
+	ExtraData           *ForkChoiceDumpExtraData `json:"extra_data"`
+}
+
+type ForkChoiceDumpExtraData struct {
+	UnrealizedJustifiedCheckpoint *Checkpoint `json:"unrealized_justified_checkpoint"`
+	UnrealizedFinalizedCheckpoint *Checkpoint `json:"unrealized_finalized_checkpoint"`
+	ProposerBoostRoot             string      `json:"proposer_boost_root"`
+	PreviousProposerBoostRoot     string      `json:"previous_proposer_boost_root"`
+	HeadRoot                      string      `json:"head_root"`
+}
+
+type ForkChoiceNode struct {
+	Slot               string                   `json:"slot"`
+	BlockRoot          string                   `json:"block_root"`
+	ParentRoot         string                   `json:"parent_root"`
+	JustifiedEpoch     string                   `json:"justified_epoch"`
+	FinalizedEpoch     string                   `json:"finalized_epoch"`
+	Weight             string                   `json:"weight"`
+	Validity           string                   `json:"validity"`
+	ExecutionBlockHash string                   `json:"execution_block_hash"`
+	ExtraData          *ForkChoiceNodeExtraData `json:"extra_data"`
+}
+
+type ForkChoiceNodeExtraData struct {
+	UnrealizedJustifiedEpoch string `json:"unrealized_justified_epoch"`
+	UnrealizedFinalizedEpoch string `json:"unrealized_finalized_epoch"`
+	Balance                  string `json:"balance"`
+	ExecutionOptimistic      bool   `json:"execution_optimistic"`
+	TimeStamp                string `json:"timestamp"`
+}
--- a/api/server/structs/endpoints_events.go
+++ b/api/server/structs/endpoints_events.go
@@ -0,0 +1,116 @@
+package structs
+
+import (
+	"encoding/json"
+)
+
+type HeadEvent struct {
+	Slot                      string `json:"slot"`
+	Block                     string `json:"block"`
+	State                     string `json:"state"`
+	EpochTransition           bool   `json:"epoch_transition"`
+	ExecutionOptimistic       bool   `json:"execution_optimistic"`
+	PreviousDutyDependentRoot string `json:"previous_duty_dependent_root"`
+	CurrentDutyDependentRoot  string `json:"current_duty_dependent_root"`
+}
+
+type BlockEvent struct {
+	Slot                string `json:"slot"`
+	Block               string `json:"block"`
+	ExecutionOptimistic bool   `json:"execution_optimistic"`
+}
+
+type AggregatedAttEventSource struct {
+	Aggregate *Attestation `json:"aggregate"`
+}
+
+type UnaggregatedAttEventSource struct {
+	AggregationBits string           `json:"aggregation_bits"`
+	Data            *AttestationData `json:"data"`
+	Signature       string           `json:"signature"`
+}
+
+type FinalizedCheckpointEvent struct {
+	Block               string `json:"block"`
+	State               string `json:"state"`
+	Epoch               string `json:"epoch"`
+	ExecutionOptimistic bool   `json:"execution_optimistic"`
+}
+
+type ChainReorgEvent struct {
+	Slot                string `json:"slot"`
+	Depth               string `json:"depth"`
+	OldHeadBlock        string `json:"old_head_block"`
+	NewHeadBlock        string `json:"old_head_state"`
+	OldHeadState        string `json:"new_head_block"`
+	NewHeadState        string `json:"new_head_state"`
+	Epoch               string `json:"epoch"`
+	ExecutionOptimistic bool   `json:"execution_optimistic"`
+}
+
+type PayloadAttributesEvent struct {
+	Version string          `json:"version"`
+	Data    json.RawMessage `json:"data"`
+}
+
+type PayloadAttributesEventData struct {
+	ProposerIndex     string          `json:"proposer_index"`
+	ProposalSlot      string          `json:"proposal_slot"`
+	ParentBlockNumber string          `json:"parent_block_number"`
+	ParentBlockRoot   string          `json:"parent_block_root"`
+	ParentBlockHash   string          `json:"parent_block_hash"`
+	PayloadAttributes json.RawMessage `json:"payload_attributes"`
+}
+
+type PayloadAttributesV1 struct {
+	Timestamp             string `json:"timestamp"`
+	PrevRandao            string `json:"prev_randao"`
+	SuggestedFeeRecipient string `json:"suggested_fee_recipient"`
+}
+
+type PayloadAttributesV2 struct {
+	Timestamp             string        `json:"timestamp"`
+	PrevRandao            string        `json:"prev_randao"`
+	SuggestedFeeRecipient string        `json:"suggested_fee_recipient"`
+	Withdrawals           []*Withdrawal `json:"withdrawals"`
+}
+
+type PayloadAttributesV3 struct {
+	Timestamp             string        `json:"timestamp"`
+	PrevRandao            string        `json:"prev_randao"`
+	SuggestedFeeRecipient string        `json:"suggested_fee_recipient"`
+	Withdrawals           []*Withdrawal `json:"withdrawals"`
+	ParentBeaconBlockRoot string        `json:"parent_beacon_block_root"`
+}
+
+type BlobSidecarEvent struct {
+	BlockRoot     string `json:"block_root"`
+	Index         string `json:"index"`
+	Slot          string `json:"slot"`
+	KzgCommitment string `json:"kzg_commitment"`
+	VersionedHash string `json:"versioned_hash"`
+}
+
+type LightClientFinalityUpdateEvent struct {
+	Version string                     `json:"version"`
+	Data    *LightClientFinalityUpdate `json:"data"`
+}
+
+type LightClientFinalityUpdate struct {
+	AttestedHeader  *BeaconBlockHeader `json:"attested_header"`
+	FinalizedHeader *BeaconBlockHeader `json:"finalized_header"`
+	FinalityBranch  []string           `json:"finality_branch"`
+	SyncAggregate   *SyncAggregate     `json:"sync_aggregate"`
+	SignatureSlot   string             `json:"signature_slot"`
+}
+
+type LightClientOptimisticUpdateEvent struct {
+	Version string                       `json:"version"`
+	Data    *LightClientOptimisticUpdate `json:"data"`
+}
+
+type LightClientOptimisticUpdate struct {
+	AttestedHeader *BeaconBlockHeader `json:"attested_header"`
+	SyncAggregate  *SyncAggregate     `json:"sync_aggregate"`
+	SignatureSlot  string             `json:"signature_slot"`
+}
--- a/api/server/structs/endpoints_lightclient.go
+++ b/api/server/structs/endpoints_lightclient.go
@@ -0,0 +1,31 @@
+package structs
+
+type LightClientBootstrapResponse struct {
+	Version string                `json:"version"`
+	Data    *LightClientBootstrap `json:"data"`
+}
+
+type LightClientBootstrap struct {
+	Header                     *BeaconBlockHeader `json:"header"`
+	CurrentSyncCommittee       *SyncCommittee     `json:"current_sync_committee"`
+	CurrentSyncCommitteeBranch []string           `json:"current_sync_committee_branch"`
+}
+
+type LightClientUpdate struct {
+	AttestedHeader          *BeaconBlockHeader `json:"attested_header"`
+	NextSyncCommittee       *SyncCommittee     `json:"next_sync_committee,omitempty"`
+	FinalizedHeader         *BeaconBlockHeader `json:"finalized_header,omitempty"`
+	SyncAggregate           *SyncAggregate     `json:"sync_aggregate"`
+	NextSyncCommitteeBranch []string           `json:"next_sync_committee_branch,omitempty"`
+	FinalityBranch          []string           `json:"finality_branch,omitempty"`
+	SignatureSlot           string             `json:"signature_slot"`
+}
+
+type LightClientUpdateWithVersion struct {
+	Version string             `json:"version"`
+	Data    *LightClientUpdate `json:"data"`
+}
+
+type LightClientUpdatesByRangeResponse struct {
+	Updates []*LightClientUpdateWithVersion `json:"updates"`
+}
--- a/api/server/structs/endpoints_node.go
+++ b/api/server/structs/endpoints_node.go
@@ -1,4 +1,4 @@
-package node
+package structs

 type SyncStatusResponse struct {
 	Data *SyncStatusResponseData `json:"data"`
@@ -63,3 +63,11 @@ type GetVersionResponse struct {
 type Version struct {
 	Version string `json:"version"`
 }
+
+type AddrRequest struct {
+	Addr string `json:"addr"`
+}
+
+type PeersResponse struct {
+	Peers []*Peer `json:"peers"`
+}
--- a/api/server/structs/endpoints_rewards.go
+++ b/api/server/structs/endpoints_rewards.go
@@ -1,4 +1,4 @@
-package rewards
+package structs

 type BlockRewardsResponse struct {
 	Data                *BlockRewards `json:"data"`
@@ -31,6 +31,7 @@ type IdealAttestationReward struct {
 	Head             string `json:"head"`
 	Target           string `json:"target"`
 	Source           string `json:"source"`
+	Inactivity       string `json:"inactivity"`
 }

 type TotalAttestationReward struct {
@@ -38,7 +39,7 @@ type TotalAttestationReward struct {
 	Head           string `json:"head"`
 	Target         string `json:"target"`
 	Source         string `json:"source"`
-	InclusionDelay string `json:"inclusion_delay"`
+	Inactivity     string `json:"inactivity"`
 }

 type SyncCommitteeRewardsResponse struct {
--- a/api/server/structs/endpoints_validator.go
+++ b/api/server/structs/endpoints_validator.go
@@ -1,37 +1,37 @@
-package validator
+package structs

 import (
 	"encoding/json"

-	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 )

 type AggregateAttestationResponse struct {
-	Data *shared.Attestation `json:"data"`
+	Data *Attestation `json:"data"`
 }

 type SubmitContributionAndProofsRequest struct {
-	Data []*shared.SignedContributionAndProof `json:"data"`
+	Data []*SignedContributionAndProof `json:"data"`
 }

 type SubmitAggregateAndProofsRequest struct {
-	Data []*shared.SignedAggregateAttestationAndProof `json:"data"`
+	Data []*SignedAggregateAttestationAndProof `json:"data"`
 }

 type SubmitSyncCommitteeSubscriptionsRequest struct {
-	Data []*shared.SyncCommitteeSubscription `json:"data"`
+	Data []*SyncCommitteeSubscription `json:"data"`
 }

 type SubmitBeaconCommitteeSubscriptionsRequest struct {
-	Data []*shared.BeaconCommitteeSubscription `json:"data"`
+	Data []*BeaconCommitteeSubscription `json:"data"`
 }

 type GetAttestationDataResponse struct {
-	Data *shared.AttestationData `json:"data"`
+	Data *AttestationData `json:"data"`
 }

 type ProduceSyncCommitteeContributionResponse struct {
-	Data *shared.SyncCommitteeContribution `json:"data"`
+	Data *SyncCommitteeContribution `json:"data"`
 }

 type GetAttesterDutiesResponse struct {
@@ -90,3 +90,31 @@ type Liveness struct {
 	Index  string `json:"index"`
 	IsLive bool   `json:"is_live"`
 }
+
+type GetValidatorCountResponse struct {
+	ExecutionOptimistic string            `json:"execution_optimistic"`
+	Finalized           string            `json:"finalized"`
+	Data                []*ValidatorCount `json:"data"`
+}
+
+type ValidatorCount struct {
+	Status string `json:"status"`
+	Count  string `json:"count"`
+}
+
+type GetValidatorPerformanceRequest struct {
+	PublicKeys [][]byte                    `json:"public_keys,omitempty"`
+	Indices    []primitives.ValidatorIndex `json:"indices,omitempty"`
+}
+
+type GetValidatorPerformanceResponse struct {
+	PublicKeys                    [][]byte `json:"public_keys,omitempty"`
+	CorrectlyVotedSource          []bool   `json:"correctly_voted_source,omitempty"`
+	CorrectlyVotedTarget          []bool   `json:"correctly_voted_target,omitempty"`
+	CorrectlyVotedHead            []bool   `json:"correctly_voted_head,omitempty"`
+	CurrentEffectiveBalances      []uint64 `json:"current_effective_balances,omitempty"`
+	BalancesBeforeEpochTransition []uint64 `json:"balances_before_epoch_transition,omitempty"`
+	BalancesAfterEpochTransition  []uint64 `json:"balances_after_epoch_transition,omitempty"`
+	MissingValidators             [][]byte `json:"missing_validators,omitempty"`
+	InactivityScores              []uint64 `json:"inactivity_scores,omitempty"`
+}
--- a/api/server/structs/other.go
+++ b/api/server/structs/other.go
@@ -0,0 +1,209 @@
+package structs
+
+type Validator struct {
+	Pubkey                     string `json:"pubkey"`
+	WithdrawalCredentials      string `json:"withdrawal_credentials"`
+	EffectiveBalance           string `json:"effective_balance"`
+	Slashed                    bool   `json:"slashed"`
+	ActivationEligibilityEpoch string `json:"activation_eligibility_epoch"`
+	ActivationEpoch            string `json:"activation_epoch"`
+	ExitEpoch                  string `json:"exit_epoch"`
+	WithdrawableEpoch          string `json:"withdrawable_epoch"`
+}
+
+type PendingAttestation struct {
+	AggregationBits string           `json:"aggregation_bits"`
+	Data            *AttestationData `json:"data"`
+	InclusionDelay  string           `json:"inclusion_delay"`
+	ProposerIndex   string           `json:"proposer_index"`
+}
+
+type HistoricalSummary struct {
+	BlockSummaryRoot string `json:"block_summary_root"`
+	StateSummaryRoot string `json:"state_summary_root"`
+}
+
+type Attestation struct {
+	AggregationBits string           `json:"aggregation_bits"`
+	Data            *AttestationData `json:"data"`
+	Signature       string           `json:"signature"`
+}
+
+type AttestationData struct {
+	Slot            string      `json:"slot"`
+	CommitteeIndex  string      `json:"index"`
+	BeaconBlockRoot string      `json:"beacon_block_root"`
+	Source          *Checkpoint `json:"source"`
+	Target          *Checkpoint `json:"target"`
+}
+
+type Checkpoint struct {
+	Epoch string `json:"epoch"`
+	Root  string `json:"root"`
+}
+
+type Committee struct {
+	Index      string   `json:"index"`
+	Slot       string   `json:"slot"`
+	Validators []string `json:"validators"`
+}
+
+type SignedContributionAndProof struct {
+	Message   *ContributionAndProof `json:"message"`
+	Signature string                `json:"signature"`
+}
+
+type ContributionAndProof struct {
+	AggregatorIndex string                     `json:"aggregator_index"`
+	Contribution    *SyncCommitteeContribution `json:"contribution"`
+	SelectionProof  string                     `json:"selection_proof"`
+}
+
+type SyncCommitteeContribution struct {
+	Slot              string `json:"slot"`
+	BeaconBlockRoot   string `json:"beacon_block_root"`
+	SubcommitteeIndex string `json:"subcommittee_index"`
+	AggregationBits   string `json:"aggregation_bits"`
+	Signature         string `json:"signature"`
+}
+
+type SignedAggregateAttestationAndProof struct {
+	Message   *AggregateAttestationAndProof `json:"message"`
+	Signature string                        `json:"signature"`
+}
+
+type AggregateAttestationAndProof struct {
+	AggregatorIndex string       `json:"aggregator_index"`
+	Aggregate       *Attestation `json:"aggregate"`
+	SelectionProof  string       `json:"selection_proof"`
+}
+
+type SyncCommitteeSubscription struct {
+	ValidatorIndex       string   `json:"validator_index"`
+	SyncCommitteeIndices []string `json:"sync_committee_indices"`
+	UntilEpoch           string   `json:"until_epoch"`
+}
+
+type BeaconCommitteeSubscription struct {
+	ValidatorIndex   string `json:"validator_index"`
+	CommitteeIndex   string `json:"committee_index"`
+	CommitteesAtSlot string `json:"committees_at_slot"`
+	Slot             string `json:"slot"`
+	IsAggregator     bool   `json:"is_aggregator"`
+}
+
+type ValidatorRegistration struct {
+	FeeRecipient string `json:"fee_recipient"`
+	GasLimit     string `json:"gas_limit"`
+	Timestamp    string `json:"timestamp"`
+	Pubkey       string `json:"pubkey"`
+}
+
+type SignedValidatorRegistration struct {
+	Message   *ValidatorRegistration `json:"message"`
+	Signature string                 `json:"signature"`
+}
+
+type FeeRecipient struct {
+	ValidatorIndex string `json:"validator_index"`
+	FeeRecipient   string `json:"fee_recipient"`
+}
+
+type SignedVoluntaryExit struct {
+	Message   *VoluntaryExit `json:"message"`
+	Signature string         `json:"signature"`
+}
+
+type VoluntaryExit struct {
+	Epoch          string `json:"epoch"`
+	ValidatorIndex string `json:"validator_index"`
+}
+
+type Fork struct {
+	PreviousVersion string `json:"previous_version"`
+	CurrentVersion  string `json:"current_version"`
+	Epoch           string `json:"epoch"`
+}
+
+type SignedBLSToExecutionChange struct {
+	Message   *BLSToExecutionChange `json:"message"`
+	Signature string                `json:"signature"`
+}
+
+type BLSToExecutionChange struct {
+	ValidatorIndex     string `json:"validator_index"`
+	FromBLSPubkey      string `json:"from_bls_pubkey"`
+	ToExecutionAddress string `json:"to_execution_address"`
+}
+
+type SyncCommitteeMessage struct {
+	Slot            string `json:"slot"`
+	BeaconBlockRoot string `json:"beacon_block_root"`
+	ValidatorIndex  string `json:"validator_index"`
+	Signature       string `json:"signature"`
+}
+
+type SyncCommittee struct {
+	Pubkeys         []string `json:"pubkeys"`
+	AggregatePubkey string   `json:"aggregate_pubkey"`
+}
+
+// SyncDetails contains information about node sync status.
+type SyncDetails struct {
+	HeadSlot     string `json:"head_slot"`
+	SyncDistance string `json:"sync_distance"`
+	IsSyncing    bool   `json:"is_syncing"`
+	IsOptimistic bool   `json:"is_optimistic"`
+	ElOffline    bool   `json:"el_offline"`
+}
+
+// SyncDetailsContainer is a wrapper for Data.
+type SyncDetailsContainer struct {
+	Data *SyncDetails `json:"data"`
+}
+
+type Eth1Data struct {
+	DepositRoot  string `json:"deposit_root"`
+	DepositCount string `json:"deposit_count"`
+	BlockHash    string `json:"block_hash"`
+}
+
+type ProposerSlashing struct {
+	SignedHeader1 *SignedBeaconBlockHeader `json:"signed_header_1"`
+	SignedHeader2 *SignedBeaconBlockHeader `json:"signed_header_2"`
+}
+
+type AttesterSlashing struct {
+	Attestation1 *IndexedAttestation `json:"attestation_1"`
+	Attestation2 *IndexedAttestation `json:"attestation_2"`
+}
+
+type Deposit struct {
+	Proof []string     `json:"proof"`
+	Data  *DepositData `json:"data"`
+}
+
+type DepositData struct {
+	Pubkey                string `json:"pubkey"`
+	WithdrawalCredentials string `json:"withdrawal_credentials"`
+	Amount                string `json:"amount"`
+	Signature             string `json:"signature"`
+}
+
+type IndexedAttestation struct {
+	AttestingIndices []string         `json:"attesting_indices"`
+	Data             *AttestationData `json:"data"`
+	Signature        string           `json:"signature"`
+}
+
+type SyncAggregate struct {
+	SyncCommitteeBits      string `json:"sync_committee_bits"`
+	SyncCommitteeSignature string `json:"sync_committee_signature"`
+}
+
+type Withdrawal struct {
+	WithdrawalIndex  string `json:"index"`
+	ValidatorIndex   string `json:"validator_index"`
+	ExecutionAddress string `json:"address"`
+	Amount           string `json:"amount"`
+}
--- a/api/server/structs/state.go
+++ b/api/server/structs/state.go
@@ -0,0 +1,142 @@
+package structs
+
+type BeaconState struct {
+	GenesisTime                 string                `json:"genesis_time"`
+	GenesisValidatorsRoot       string                `json:"genesis_validators_root"`
+	Slot                        string                `json:"slot"`
+	Fork                        *Fork                 `json:"fork"`
+	LatestBlockHeader           *BeaconBlockHeader    `json:"latest_block_header"`
+	BlockRoots                  []string              `json:"block_roots"`
+	StateRoots                  []string              `json:"state_roots"`
+	HistoricalRoots             []string              `json:"historical_roots"`
+	Eth1Data                    *Eth1Data             `json:"eth1_data"`
+	Eth1DataVotes               []*Eth1Data           `json:"eth1_data_votes"`
+	Eth1DepositIndex            string                `json:"eth1_deposit_index"`
+	Validators                  []*Validator          `json:"validators"`
+	Balances                    []string              `json:"balances"`
+	RandaoMixes                 []string              `json:"randao_mixes"`
+	Slashings                   []string              `json:"slashings"`
+	PreviousEpochAttestations   []*PendingAttestation `json:"previous_epoch_attestations"`
+	CurrentEpochAttestations    []*PendingAttestation `json:"current_epoch_attestations"`
+	JustificationBits           string                `json:"justification_bits"`
+	PreviousJustifiedCheckpoint *Checkpoint           `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint  *Checkpoint           `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint         *Checkpoint           `json:"finalized_checkpoint"`
+}
+
+type BeaconStateAltair struct {
+	GenesisTime                 string             `json:"genesis_time"`
+	GenesisValidatorsRoot       string             `json:"genesis_validators_root"`
+	Slot                        string             `json:"slot"`
+	Fork                        *Fork              `json:"fork"`
+	LatestBlockHeader           *BeaconBlockHeader `json:"latest_block_header"`
+	BlockRoots                  []string           `json:"block_roots"`
+	StateRoots                  []string           `json:"state_roots"`
+	HistoricalRoots             []string           `json:"historical_roots"`
+	Eth1Data                    *Eth1Data          `json:"eth1_data"`
+	Eth1DataVotes               []*Eth1Data        `json:"eth1_data_votes"`
+	Eth1DepositIndex            string             `json:"eth1_deposit_index"`
+	Validators                  []*Validator       `json:"validators"`
+	Balances                    []string           `json:"balances"`
+	RandaoMixes                 []string           `json:"randao_mixes"`
+	Slashings                   []string           `json:"slashings"`
+	PreviousEpochParticipation  []string           `json:"previous_epoch_participation"`
+	CurrentEpochParticipation   []string           `json:"current_epoch_participation"`
+	JustificationBits           string             `json:"justification_bits"`
+	PreviousJustifiedCheckpoint *Checkpoint        `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint  *Checkpoint        `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint         *Checkpoint        `json:"finalized_checkpoint"`
+	InactivityScores            []string           `json:"inactivity_scores"`
+	CurrentSyncCommittee        *SyncCommittee     `json:"current_sync_committee"`
+	NextSyncCommittee           *SyncCommittee     `json:"next_sync_committee"`
+}
+
+type BeaconStateBellatrix struct {
+	GenesisTime                  string                  `json:"genesis_time"`
+	GenesisValidatorsRoot        string                  `json:"genesis_validators_root"`
+	Slot                         string                  `json:"slot"`
+	Fork                         *Fork                   `json:"fork"`
+	LatestBlockHeader            *BeaconBlockHeader      `json:"latest_block_header"`
+	BlockRoots                   []string                `json:"block_roots"`
+	StateRoots                   []string                `json:"state_roots"`
+	HistoricalRoots              []string                `json:"historical_roots"`
+	Eth1Data                     *Eth1Data               `json:"eth1_data"`
+	Eth1DataVotes                []*Eth1Data             `json:"eth1_data_votes"`
+	Eth1DepositIndex             string                  `json:"eth1_deposit_index"`
+	Validators                   []*Validator            `json:"validators"`
+	Balances                     []string                `json:"balances"`
+	RandaoMixes                  []string                `json:"randao_mixes"`
+	Slashings                    []string                `json:"slashings"`
+	PreviousEpochParticipation   []string                `json:"previous_epoch_participation"`
+	CurrentEpochParticipation    []string                `json:"current_epoch_participation"`
+	JustificationBits            string                  `json:"justification_bits"`
+	PreviousJustifiedCheckpoint  *Checkpoint             `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint   *Checkpoint             `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint          *Checkpoint             `json:"finalized_checkpoint"`
+	InactivityScores             []string                `json:"inactivity_scores"`
+	CurrentSyncCommittee         *SyncCommittee          `json:"current_sync_committee"`
+	NextSyncCommittee            *SyncCommittee          `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader *ExecutionPayloadHeader `json:"latest_execution_payload_header"`
+}
+
+type BeaconStateCapella struct {
+	GenesisTime                  string                         `json:"genesis_time"`
+	GenesisValidatorsRoot        string                         `json:"genesis_validators_root"`
+	Slot                         string                         `json:"slot"`
+	Fork                         *Fork                          `json:"fork"`
+	LatestBlockHeader            *BeaconBlockHeader             `json:"latest_block_header"`
+	BlockRoots                   []string                       `json:"block_roots"`
+	StateRoots                   []string                       `json:"state_roots"`
+	HistoricalRoots              []string                       `json:"historical_roots"`
+	Eth1Data                     *Eth1Data                      `json:"eth1_data"`
+	Eth1DataVotes                []*Eth1Data                    `json:"eth1_data_votes"`
+	Eth1DepositIndex             string                         `json:"eth1_deposit_index"`
+	Validators                   []*Validator                   `json:"validators"`
+	Balances                     []string                       `json:"balances"`
+	RandaoMixes                  []string                       `json:"randao_mixes"`
+	Slashings                    []string                       `json:"slashings"`
+	PreviousEpochParticipation   []string                       `json:"previous_epoch_participation"`
+	CurrentEpochParticipation    []string                       `json:"current_epoch_participation"`
+	JustificationBits            string                         `json:"justification_bits"`
+	PreviousJustifiedCheckpoint  *Checkpoint                    `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint   *Checkpoint                    `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint          *Checkpoint                    `json:"finalized_checkpoint"`
+	InactivityScores             []string                       `json:"inactivity_scores"`
+	CurrentSyncCommittee         *SyncCommittee                 `json:"current_sync_committee"`
+	NextSyncCommittee            *SyncCommittee                 `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader *ExecutionPayloadHeaderCapella `json:"latest_execution_payload_header"`
+	NextWithdrawalIndex          string                         `json:"next_withdrawal_index"`
+	NextWithdrawalValidatorIndex string                         `json:"next_withdrawal_validator_index"`
+	HistoricalSummaries          []*HistoricalSummary           `json:"historical_summaries"`
+}
+
+type BeaconStateDeneb struct {
+	GenesisTime                  string                       `json:"genesis_time"`
+	GenesisValidatorsRoot        string                       `json:"genesis_validators_root"`
+	Slot                         string                       `json:"slot"`
+	Fork                         *Fork                        `json:"fork"`
+	LatestBlockHeader            *BeaconBlockHeader           `json:"latest_block_header"`
+	BlockRoots                   []string                     `json:"block_roots"`
+	StateRoots                   []string                     `json:"state_roots"`
+	HistoricalRoots              []string                     `json:"historical_roots"`
+	Eth1Data                     *Eth1Data                    `json:"eth1_data"`
+	Eth1DataVotes                []*Eth1Data                  `json:"eth1_data_votes"`
+	Eth1DepositIndex             string                       `json:"eth1_deposit_index"`
+	Validators                   []*Validator                 `json:"validators"`
+	Balances                     []string                     `json:"balances"`
+	RandaoMixes                  []string                     `json:"randao_mixes"`
+	Slashings                    []string                     `json:"slashings"`
+	PreviousEpochParticipation   []string                     `json:"previous_epoch_participation"`
+	CurrentEpochParticipation    []string                     `json:"current_epoch_participation"`
+	JustificationBits            string                       `json:"justification_bits"`
+	PreviousJustifiedCheckpoint  *Checkpoint                  `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint   *Checkpoint                  `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint          *Checkpoint                  `json:"finalized_checkpoint"`
+	InactivityScores             []string                     `json:"inactivity_scores"`
+	CurrentSyncCommittee         *SyncCommittee               `json:"current_sync_committee"`
+	NextSyncCommittee            *SyncCommittee               `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader *ExecutionPayloadHeaderDeneb `json:"latest_execution_payload_header"`
+	NextWithdrawalIndex          string                       `json:"next_withdrawal_index"`
+	NextWithdrawalValidatorIndex string                       `json:"next_withdrawal_validator_index"`
+	HistoricalSummaries          []*HistoricalSummary         `json:"historical_summaries"`
+}
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -6,6 +6,7 @@ go_library(
        "chain_info.go",
        "chain_info_forkchoice.go",
        "currently_syncing_block.go",
+        "defragment.go",
        "error.go",
        "execution_engine.go",
        "forkchoice_update_execution.go",
@@ -26,6 +27,7 @@ go_library(
        "receive_blob.go",
        "receive_block.go",
        "service.go",
+        "tracked_proposer.go",
        "weak_subjectivity_checks.go",
    ],
    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain",
@@ -49,10 +51,10 @@ 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",
@@ -99,26 +101,22 @@ go_library(
    ],
 )

-test_suite(
-    name = "go_default_test",
-    tests = [
-        ":go_raceoff_test",
-        ":go_raceon_test",
-    ],
-)
-
 go_test(
-    name = "go_raceoff_test",
+    name = "go_default_test",
    size = "medium",
    srcs = [
        "blockchain_test.go",
+        "chain_info_norace_test.go",
        "chain_info_test.go",
        "checktags_test.go",
+        "error_test.go",
        "execution_engine_test.go",
        "forkchoice_update_execution_test.go",
        "head_sync_committee_info_test.go",
        "head_test.go",
+        "init_sync_process_block_test.go",
        "init_test.go",
+        "lightclient_test.go",
        "log_test.go",
        "metrics_test.go",
        "mock_test.go",
@@ -127,98 +125,67 @@ go_test(
        "process_block_test.go",
        "receive_attestation_test.go",
        "receive_block_test.go",
+        "service_norace_test.go",
        "service_test.go",
        "setup_test.go",
        "weak_subjectivity_checks_test.go",
    ],
    embed = [":go_default_library"],
    gotags = ["develop"],
+    tags = ["CI_race_detection"],
    deps = [
        "//async/event:go_default_library",
        "//beacon-chain/blockchain/testing:go_default_library",
+        "//beacon-chain/cache:go_default_library",
        "//beacon-chain/cache/depositcache:go_default_library",
        "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
+        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/testing:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/execution/testing:go_default_library",
+        "//beacon-chain/forkchoice:go_default_library",
+        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
        "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/operations/attestations:go_default_library",
+        "//beacon-chain/operations/blstoexec:go_default_library",
+        "//beacon-chain/operations/slashings:go_default_library",
+        "//beacon-chain/operations/voluntaryexits:go_default_library",
        "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/startup:go_default_library",
+        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/state-native:go_default_library",
-        "//beacon-chain/state/stateutil:go_default_library",
+        "//beacon-chain/state/stategen:go_default_library",
+        "//config/features:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/primitives:go_default_library",
        "//container/trie:go_default_library",
+        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/eth/v1:go_default_library",
+        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
-        "@com_github_ethereum_go_ethereum//:go_default_library",
-        "@com_github_ethereum_go_ethereum//common:go_default_library",
-        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
-        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
-        "@in_gopkg_d4l3k_messagediff_v1//:go_default_library",
-        "@org_golang_google_protobuf//proto:go_default_library",
-        "@org_golang_x_net//context:go_default_library",
-    ],
-)
-
-go_test(
-    name = "go_raceon_test",
-    srcs = [
-        "chain_info_norace_test.go",
-        "checktags_test.go",
-        "init_test.go",
-        "mock_test.go",
-        "receive_block_test.go",
-        "service_norace_test.go",
-        "setup_test.go",
-    ],
-    embed = [":go_default_library"],
-    gc_goopts = [
-        # Go 1.14 enables checkptr by default when building with -race or -msan. There is a pointer
-        # issue in boltdb, so must disable checkptr at compile time. This flag can be removed once
-        # the project is migrated to etcd's version of boltdb and the issue has been fixed.
-        # See: https://github.com/etcd-io/bbolt/issues/187.
-        "-d=checkptr=0",
-    ],
-    gotags = ["develop"],
-    race = "on",
-    tags = ["race_on"],
-    deps = [
-        "//async/event:go_default_library",
-        "//beacon-chain/blockchain/testing:go_default_library",
-        "//beacon-chain/cache/depositcache:go_default_library",
-        "//beacon-chain/core/blocks:go_default_library",
-        "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/transition:go_default_library",
-        "//beacon-chain/db:go_default_library",
-        "//beacon-chain/db/testing:go_default_library",
-        "//beacon-chain/execution:go_default_library",
-        "//beacon-chain/execution/testing:go_default_library",
-        "//beacon-chain/forkchoice/types:go_default_library",
-        "//beacon-chain/p2p:go_default_library",
-        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
-        "//container/trie:go_default_library",
-        "//encoding/bytesutil:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-        "//testing/assert:go_default_library",
-        "//testing/require:go_default_library",
-        "//testing/util:go_default_library",
-        "@com_github_ethereum_go_ethereum//:go_default_library",
+        "//time:go_default_library",
+        "//time/slots:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
+        "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
-        "@org_golang_x_net//context:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/chain_info.go
+++ b/beacon-chain/blockchain/chain_info.go
@@ -6,7 +6,10 @@ import (
 	"time"

 	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	f "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
 	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"
@@ -18,7 +21,6 @@ import (
 	"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"
 )

 // ChainInfoFetcher defines a common interface for methods in blockchain service which
@@ -75,6 +77,7 @@ 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
 }
@@ -333,12 +336,21 @@ 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
@@ -464,6 +476,13 @@ func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool,
 	return !isCanonical, nil
 }

+// TargetRootForEpoch wraps the corresponding method in forkchoice
+func (s *Service) TargetRootForEpoch(root [32]byte, epoch primitives.Epoch) ([32]byte, error) {
+	s.cfg.ForkChoiceStore.RLock()
+	defer s.cfg.ForkChoiceStore.RUnlock()
+	return s.cfg.ForkChoiceStore.TargetRootForEpoch(root, epoch)
+}
+
 // Ancestor returns the block root of an ancestry block from the input block root.
 //
 // Spec pseudocode definition:
@@ -537,3 +556,10 @@ 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
@@ -22,6 +22,13 @@ 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_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -429,6 +429,11 @@ 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
@@ -0,0 +1,27 @@
+package blockchain
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
+	"github.com/prysmaticlabs/prysm/v4/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
@@ -28,6 +28,8 @@ var (
 	// ErrNotCheckpoint is returned when a given checkpoint is not a
 	// checkpoint in any chain known to forkchoice
 	ErrNotCheckpoint = errors.New("not a checkpoint in forkchoice")
+	// ErrNilHead is returned when no head is present in the blockchain service.
+	ErrNilHead = errors.New("nil head")
 )

 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -7,11 +7,11 @@ import (

 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
 	"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"
@@ -32,21 +32,18 @@ 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 *notifyForkchoiceUpdateArg) (*enginev1.PayloadIDBytes, error) {
+func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*enginev1.PayloadIDBytes, error) {
 	ctx, span := trace.StartSpan(ctx, "blockChain.notifyForkchoiceUpdate")
 	defer span.End()

-	headBlk := arg.headBlock
+	if arg.headBlock.IsNil() {
+		log.Error("Head block is nil")
+		return nil, nil
+	}
+	headBlk := arg.headBlock.Block()
 	if headBlk == nil || headBlk.IsNil() || headBlk.Body().IsNil() {
 		log.Error("Head block is nil")
 		return nil, nil
@@ -72,11 +69,10 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 		SafeBlockHash:      justifiedHash[:],
 		FinalizedBlockHash: finalizedHash[:],
 	}
-
-	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 arg.attributes == nil {
+		arg.attributes = payloadattribute.EmptyWithVersion(headBlk.Version())
+	}
+	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, arg.attributes)
 	if err != nil {
 		switch err {
 		case execution.ErrAcceptedSyncingPayloadStatus:
@@ -122,10 +118,11 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 				log.WithError(err).Error("Could not get head state")
 				return nil, nil
 			}
-			pid, err := s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
-				headState: st,
-				headRoot:  r,
-				headBlock: b.Block(),
+			pid, err := s.notifyForkchoiceUpdate(ctx, &fcuConfig{
+				headState:  st,
+				headRoot:   r,
+				headBlock:  b,
+				attributes: arg.attributes,
 			})
 			if err != nil {
 				return nil, err // Returning err because it's recursive here.
@@ -153,7 +150,9 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 		log.WithError(err).Error("Could not set head root to valid")
 		return nil, nil
 	}
-	// If the forkchoice update call has an attribute, update the proposer payload ID cache.
+	// 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 hasAttr && payloadID != nil {
 		var pId [8]byte
 		copy(pId[:], payloadID[:])
@@ -162,7 +161,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 			"headSlot":  headBlk.Slot(),
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
-		s.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(nextSlot, proposerId, pId, arg.headRoot)
+		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
@@ -277,56 +276,50 @@ 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) (bool, payloadattribute.Attributer, primitives.ValidatorIndex) {
+func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState, slot primitives.Slot, headRoot []byte) payloadattribute.Attributer {
 	emptyAttri := payloadattribute.EmptyWithVersion(st.Version())
-	// 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.
+	// 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
+		}
+	}
 	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 false, emptyAttri, 0
+			return emptyAttri
 		}
 	}
+	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 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
+		return emptyAttri
 	}

 	// 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 false, emptyAttri, 0
+		return emptyAttri
 	}

 	var attr payloadattribute.Attributer
@@ -335,51 +328,51 @@ 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 false, emptyAttri, 0
+			return emptyAttri
 		}
 		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV3{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: feeRecipient.Bytes(),
+			SuggestedFeeRecipient: val.FeeRecipient[:],
 			Withdrawals:           withdrawals,
 			ParentBeaconBlockRoot: headRoot,
 		})
 		if err != nil {
 			log.WithError(err).Error("Could not get payload attribute")
-			return false, emptyAttri, 0
+			return emptyAttri
 		}
 	case version.Capella:
 		withdrawals, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
-			return false, emptyAttri, 0
+			return emptyAttri
 		}
 		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV2{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: feeRecipient.Bytes(),
+			SuggestedFeeRecipient: val.FeeRecipient[:],
 			Withdrawals:           withdrawals,
 		})
 		if err != nil {
 			log.WithError(err).Error("Could not get payload attribute")
-			return false, emptyAttri, 0
+			return emptyAttri
 		}
 	case version.Bellatrix:
 		attr, err = payloadattribute.New(&enginev1.PayloadAttributes{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: feeRecipient.Bytes(),
+			SuggestedFeeRecipient: val.FeeRecipient[:],
 		})
 		if err != nil {
 			log.WithError(err).Error("Could not get payload attribute")
-			return false, emptyAttri, 0
+			return emptyAttri
 		}
 	default:
 		log.WithField("version", st.Version()).Error("Could not get payload attribute due to unknown state version")
-		return false, emptyAttri, 0
+		return emptyAttri
 	}

-	return true, attr, proposerID
+	return attr
 }

 // removeInvalidBlockAndState removes the invalid block, blob and its corresponding state from the cache and DB.
@@ -394,9 +387,9 @@ 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
 		}
-		// No op if the sidecar does not exist.
-		if err := s.cfg.BeaconDB.DeleteBlobSidecars(ctx, root); err != nil {
-			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")
 		}
 	}
 	return nil
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -26,11 +26,10 @@ import (
 	"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, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
+	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

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

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

 	pid := &v1.PayloadIDBytes{1}
@@ -73,20 +75,20 @@ 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 := &notifyForkchoiceUpdateArg{
+	arg := &fcuConfig{
 		headState: s,
 		headRoot:  [32]byte{},
 		headBlock: b,
 	}

-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(1, 0, [8]byte{}, [32]byte{})
+	service.cfg.PayloadIDCache.Set(1, [32]byte{}, [8]byte{})
 	got, err := service.notifyForkchoiceUpdate(ctx, arg)
 	require.NoError(t, err)
 	require.DeepEqual(t, got, pid) // We still get a payload ID even though the state is bad. This means it returns until the end.
 }

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

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

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

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

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

 	require.NoError(t, beaconDB.SaveState(ctx, st, bra))
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bra))
-	a := &notifyForkchoiceUpdateArg{
+	a := &fcuConfig{
 		headState: st,
-		headBlock: wbd.Block(),
+		headBlock: wbd,
 		headRoot:  brd,
 	}
 	_, err = service.notifyForkchoiceUpdate(ctx, a)
@@ -334,7 +338,7 @@ 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, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
+	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

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

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

 	phase0State, _ := util.DeterministicGenesisState(t, 1)
@@ -492,8 +496,10 @@ 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),
 				},
 			},
 		},
@@ -595,8 +601,10 @@ 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),
 							},
 						},
 					},
@@ -709,7 +717,7 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	cfg.TerminalTotalDifficulty = "2"
 	params.OverrideBeaconConfig(cfg)

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

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

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

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

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

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

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

 	// Cache hit, advance state, no fee recipient
-	suggestedVid := primitives.ValidatorIndex(1)
+	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
 	slot := primitives.Slot(1)
-	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)
+	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.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")
-	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)
+	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.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
 	a, err = attr.Withdrawals()
 	require.NoError(t, err)
@@ -861,35 +856,30 @@ func Test_GetPayloadAttributeV2(t *testing.T) {
 }

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

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

 	// Cache hit, advance state, no fee recipient
-	suggestedVid := primitives.ValidatorIndex(1)
 	slot := primitives.Slot(1)
-	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)
+	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())
 	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")
-	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)
+	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.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
 	a, err = attr.Withdrawals()
 	require.NoError(t, err)
@@ -1112,3 +1102,35 @@ 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
@@ -8,20 +8,15 @@ import (
 	"github.com/pkg/errors"
 	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"
+	payloadattribute "github.com/prysmaticlabs/prysm/v4/consensus-types/payload-attribute"
 	"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()
@@ -49,48 +44,69 @@ 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
+	if err := s.computePayloadAttributes(cfg, fcuArgs); err != nil {
+		log.WithError(err).Error("could not compute payload attributes")
+		return
+	}
+	if fcuArgs.attributes.IsEmpty() {
+		return
+	}
+	s.cfg.ForkChoiceStore.RLock()
+	defer s.cfg.ForkChoiceStore.RUnlock()
+	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.
-// it returns true if the new head is updated
-func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, newHeadRoot [32]byte, proposingSlot primitives.Slot) (bool, error) {
+func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuConfig) 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)
-
-	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)
+	_, err := s.notifyForkchoiceUpdate(ctx, args)
 	if err != nil {
-		log.WithError(err).Error("Could not get forkchoice update argument")
-		return false, nil
+		return errors.Wrap(err, "could not notify forkchoice update")
 	}

-	_, 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 {
+	if err := s.saveHead(ctx, args.headRoot, args.headBlock, args.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(headBlock); err != nil {
+	if err := s.pruneAttsFromPool(args.headBlock); err != nil {
 		log.WithError(err).Error("could not prune attestations from pool")
 	}
-	return true, nil
+	return 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
@@ -17,15 +17,6 @@ import (
 	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)
@@ -67,33 +58,14 @@ 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.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)
+	service.cfg.PayloadIDCache = cache.NewPayloadIDCache()
+	service.cfg.TrackedValidatorsCache = cache.NewTrackedValidatorsCache()

-	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)
@@ -107,13 +79,7 @@ func TestService_forkchoiceUpdateWithExecution_exceptionalCases(t *testing.T) {
 		block: wsb,
 		state: st,
 	}
-	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
+	service.cfg.PayloadIDCache.Set(2, [32]byte{2}, [8]byte{1})
 	b = util.NewBeaconBlock()
 	b.Block.Slot = 3
 	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b)
@@ -125,25 +91,22 @@ func TestService_forkchoiceUpdateWithExecution_exceptionalCases(t *testing.T) {
 		block: wsb,
 		state: st,
 	}
-	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.ValidatorIndex(1), vId)
-	require.Equal(t, [8]byte{1}, payloadID)
+	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))

-	// 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)
+	payloadID, has := service.cfg.PayloadIDCache.PayloadID(2, [32]byte{2})
+	require.Equal(t, true, has)
+	require.Equal(t, primitives.PayloadID{1}, payloadID)
 }

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

 	altairBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockAltair())
@@ -182,10 +145,14 @@ func TestService_forkchoiceUpdateWithExecution_SameHeadRootNewProposer(t *testin
 	service.head.root = r
 	service.head.block = sb
 	service.head.state = st
-	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)
-
+	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))
 }

 func TestShouldOverrideFCU(t *testing.T) {
--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -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 {
-	ctx, span := trace.StartSpan(ctx, "blockChain.headState")
+	_, 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 {
-	ctx, span := trace.StartSpan(ctx, "blockChain.headStateReadOnly")
+	_, span := trace.StartSpan(ctx, "blockChain.headStateReadOnly")
 	defer span.End()

 	return s.head.state
--- a/beacon-chain/blockchain/kzg/BUILD.bazel
+++ b/beacon-chain/blockchain/kzg/BUILD.bazel
@@ -10,7 +10,7 @@ go_library(
    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/kzg",
    visibility = ["//visibility:public"],
    deps = [
-        "//proto/prysm/v1alpha1:go_default_library",
+        "//consensus-types/blocks:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
@@ -24,8 +24,10 @@ go_test(
    ],
    embed = [":go_default_library"],
    deps = [
-        "//proto/prysm/v1alpha1:go_default_library",
+        "//consensus-types/blocks: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",
+        "@com_github_sirupsen_logrus//:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/kzg/validation.go
+++ b/beacon-chain/blockchain/kzg/validation.go
@@ -1,32 +1,28 @@
 package kzg

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

-// 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 {
+// 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 {
 		return nil
 	}
-	blobs := make([]GoKZG.Blob, len(commitments))
-	proofs := make([]GoKZG.KZGProof, len(commitments))
-	cmts := make([]GoKZG.KZGCommitment, len(commitments))
+	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))
 	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)
 }
--- a/beacon-chain/blockchain/kzg/validation_test.go
+++ b/beacon-chain/blockchain/kzg/validation_test.go
@@ -1,17 +1,66 @@
 package kzg

 import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
 	"testing"

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

-func TestIsDataAvailable(t *testing.T) {
-	sidecars := make([]*ethpb.DeprecatedBlobSidecar, 0)
-	commitments := make([][]byte, 0)
-	require.NoError(t, IsDataAvailable(commitments, sidecars))
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func GetRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// Returns a random blob using the passed seed as entropy
+func GetRandBlob(seed int64) GoKZG.Blob {
+	var blob GoKZG.Blob
+	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
+		fieldElementBytes := GetRandFieldElement(seed + int64(i))
+		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
+	}
+	return blob
+}
+
+func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZGProof, error) {
+	commitment, err := kzgContext.BlobToKZGCommitment(blob, 0)
+	if err != nil {
+		return GoKZG.KZGCommitment{}, GoKZG.KZGProof{}, err
+	}
+	proof, err := kzgContext.ComputeBlobKZGProof(blob, commitment, 0)
+	if err != nil {
+		return GoKZG.KZGCommitment{}, GoKZG.KZGProof{}, err
+	}
+	return commitment, proof, err
+}
+
+func TestVerify(t *testing.T) {
+	sidecars := make([]blocks.ROBlob, 0)
+	require.NoError(t, Verify(sidecars...))
 }

 func TestBytesToAny(t *testing.T) {
@@ -23,3 +72,13 @@ func TestBytesToAny(t *testing.T) {
 	require.DeepEqual(t, commitment, bytesToCommitment(bytes))
 	require.DeepEqual(t, proof, bytesToKZGProof(bytes))
 }
+
+func TestGenerateCommitmentAndProof(t *testing.T) {
+	blob := GetRandBlob(123)
+	commitment, proof, err := GenerateCommitmentAndProof(blob)
+	require.NoError(t, err)
+	expectedCommitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}
+	expectedProof := GoKZG.KZGProof{128, 110, 116, 170, 56, 111, 126, 87, 229, 234, 211, 42, 110, 150, 129, 206, 73, 142, 167, 243, 90, 149, 240, 240, 236, 204, 143, 182, 229, 249, 81, 27, 153, 171, 83, 70, 144, 250, 42, 1, 188, 215, 71, 235, 30, 7, 175, 86}
+	require.Equal(t, expectedCommitment, commitment)
+	require.Equal(t, expectedProof, proof)
+}
--- a/beacon-chain/blockchain/log.go
+++ b/beacon-chain/blockchain/log.go
@@ -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) error {
+func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte, justified, finalized *ethpb.Checkpoint, receivedTime time.Time, genesisTime uint64, daWaitedTime time.Duration) 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),
+			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime) - daWaitedTime,
 			"deposits":                  len(block.Body().Deposits()),
 		}
 		log.WithFields(lf).Debug("Synced new block")
--- a/beacon-chain/blockchain/metrics.go
+++ b/beacon-chain/blockchain/metrics.go
@@ -182,6 +182,10 @@ 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",
@@ -358,6 +362,7 @@ 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/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -69,10 +69,18 @@ func WithDepositCache(c cache.DepositCache) Option {
 	}
 }

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

-// WithClockSychronizer sets the ClockSetter/ClockWaiter values to be used by services that need to block until
+// WithClockSynchronizer 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 {
@@ -190,3 +198,10 @@ 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/process_attestation_test.go
+++ b/beacon-chain/blockchain/process_attestation_test.go
@@ -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)}))

-	s2, err := service.getAttPreState(ctx, cp2)
+	_, 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
@@ -6,12 +6,15 @@ import (
 	"time"

 	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+
 	"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/das"
 	"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"
@@ -28,8 +31,6 @@ import (
 	"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"
 )

 // A custom slot deadline for processing state slots in our cache.
@@ -41,106 +42,71 @@ 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(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, postState state.BeaconState, isValidPayload bool) error {
-	ctx, span := trace.StartSpan(ctx, "blockChain.onBlock")
+func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
+	ctx, span := trace.StartSpan(cfg.ctx, "blockChain.onBlock")
 	defer span.End()
-	if err := consensusblocks.BeaconBlockIsNil(signed); err != nil {
+	cfg.ctx = ctx
+	if err := consensusblocks.BeaconBlockIsNil(cfg.signed); err != nil {
 		return invalidBlock{error: err}
 	}
 	startTime := time.Now()
-	b := signed.Block()
+	fcuArgs := &fcuConfig{}

-	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())
+	if s.inRegularSync() {
+		defer s.handleSecondFCUCall(cfg, fcuArgs)
 	}
-	if err := s.handleBlockAttestations(ctx, signed.Block(), postState); err != nil {
+	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 {
 		return errors.Wrap(err, "could not handle block's attestations")
 	}

-	s.InsertSlashingsToForkChoiceStore(ctx, signed.Block().Body().AttesterSlashings())
-	if isValidPayload {
-		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, blockRoot); err != nil {
+	s.InsertSlashingsToForkChoiceStore(ctx, cfg.signed.Block().Body().AttesterSlashings())
+	if cfg.isValidPayload {
+		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, cfg.blockRoot); err != nil {
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
-
 	start := time.Now()
-	headRoot, err := s.cfg.ForkChoiceStore.Head(ctx)
+	cfg.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()))
-
-	// 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
+	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")
 	}

-	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
 }

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

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

@@ -265,8 +231,8 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 				return err
 			}
 		}
-		if err := s.databaseDACheck(ctx, b); err != nil {
-			return errors.Wrap(err, "could not validate blob data availability")
+		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())
 		}
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
 			JustifiedCheckpoint: jCheckpoints[i],
@@ -322,10 +288,10 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
-	arg := &notifyForkchoiceUpdateArg{
+	arg := &fcuConfig{
 		headState: preState,
 		headRoot:  lastBR,
-		headBlock: lastB.Block(),
+		headBlock: lastB,
 	}
 	if _, err := s.notifyForkchoiceUpdate(ctx, arg); err != nil {
 		return err
@@ -333,37 +299,6 @@ 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 {
@@ -381,10 +316,27 @@ func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.Beacon
 		if err := helpers.UpdateCommitteeCache(slotCtx, st, e+1); err != nil {
 			log.WithError(err).Warn("Could not update committee cache")
 		}
-		if err := helpers.UpdateProposerIndicesInCache(slotCtx, st, e+1); err != nil {
-			log.WithError(err).Warn("Failed to cache next epoch proposers")
-		}
 	}()
+	// 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")
+	}
 	return nil
 }

@@ -633,10 +585,15 @@ 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)
@@ -654,10 +611,16 @@ 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")
 	}
-	// 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 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() {
 		return
 	}

@@ -669,13 +632,14 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 		return
 	}
 	s.headLock.RUnlock()
-	s.cfg.ForkChoiceStore.RLock()
-	_, err = s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
-		headState: headState,
-		headRoot:  headRoot,
-		headBlock: headBlock.Block(),
-	})
-	s.cfg.ForkChoiceStore.RUnlock()
+
+	fcuArgs := &fcuConfig{
+		headState:  headState,
+		headRoot:   headRoot,
+		headBlock:  headBlock,
+		attributes: attribute,
+	}
+	_, err = s.notifyForkchoiceUpdate(ctx, fcuArgs)
 	if err != nil {
 		log.WithError(err).Debug("could not perform late block tasks: failed to update forkchoice with engine")
 	}
--- a/beacon-chain/blockchain/process_block_helpers.go
+++ b/beacon-chain/blockchain/process_block_helpers.go
@@ -3,21 +3,28 @@ package blockchain
 import (
 	"context"
 	"fmt"
+	"time"

 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
+
+	"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/transition"
 	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"
+	"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/encoding/bytesutil"
 	mathutil "github.com/prysmaticlabs/prysm/v4/math"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v4/proto/eth/v2"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"go.opencensus.io/trace"
 )

 // CurrentSlot returns the current slot based on time.
@@ -25,6 +32,252 @@ func (s *Service) CurrentSlot() primitives.Slot {
 	return slots.CurrentSlot(uint64(s.genesisTime.Unix()))
 }

+// getFCUArgs returns the arguments to call forkchoice update
+func (s *Service) getFCUArgs(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) error {
+	if err := s.getFCUArgsEarlyBlock(cfg, fcuArgs); err != nil {
+		return err
+	}
+	if !s.inRegularSync() {
+		return nil
+	}
+	slot := cfg.signed.Block().Slot()
+	if slots.WithinVotingWindow(uint64(s.genesisTime.Unix()), slot) {
+		return nil
+	}
+	return s.computePayloadAttributes(cfg, fcuArgs)
+}
+
+func (s *Service) getFCUArgsEarlyBlock(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) error {
+	if cfg.blockRoot == cfg.headRoot {
+		fcuArgs.headState = cfg.postState
+		fcuArgs.headBlock = cfg.signed
+		fcuArgs.headRoot = cfg.headRoot
+		fcuArgs.proposingSlot = s.CurrentSlot() + 1
+		return nil
+	}
+	return s.fcuArgsNonCanonicalBlock(cfg, fcuArgs)
+}
+
+// logNonCanonicalBlockReceived prints a message informing that the received
+// block is not the head of the chain. It requires the caller holds a lock on
+// Foprkchoice.
+func (s *Service) logNonCanonicalBlockReceived(blockRoot [32]byte, headRoot [32]byte) {
+	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")
+}
+
+// fcuArgsNonCanonicalBlock returns the arguments to the FCU call when the
+// incoming block is non-canonical, that is, based on the head root.
+func (s *Service) fcuArgsNonCanonicalBlock(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) error {
+	headState, headBlock, err := s.getStateAndBlock(cfg.ctx, cfg.headRoot)
+	if err != nil {
+		return err
+	}
+	fcuArgs.headState = headState
+	fcuArgs.headBlock = headBlock
+	fcuArgs.headRoot = cfg.headRoot
+	fcuArgs.proposingSlot = s.CurrentSlot() + 1
+	return nil
+}
+
+// sendStateFeedOnBlock sends an event that a new block has been synced
+func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
+	optimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(cfg.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:        cfg.signed.Block().Slot(),
+			BlockRoot:   cfg.blockRoot,
+			SignedBlock: cfg.signed,
+			Verified:    true,
+			Optimistic:  optimistic,
+		},
+	})
+}
+
+// sendLightClientFeeds sends the light client feeds when feature flag is enabled.
+func (s *Service) sendLightClientFeeds(cfg *postBlockProcessConfig) {
+	if features.Get().EnableLightClient {
+		if _, err := s.sendLightClientOptimisticUpdate(cfg.ctx, cfg.signed, cfg.postState); err != nil {
+			log.WithError(err).Error("Failed to send light client optimistic update")
+		}
+
+		// Get the finalized checkpoint
+		finalized := s.ForkChoicer().FinalizedCheckpoint()
+
+		// LightClientFinalityUpdate needs super majority
+		s.tryPublishLightClientFinalityUpdate(cfg.ctx, cfg.signed, finalized, cfg.postState)
+	}
+}
+
+func (s *Service) tryPublishLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock, finalized *forkchoicetypes.Checkpoint, postState state.BeaconState) {
+	if finalized.Epoch <= s.lastPublishedLightClientEpoch {
+		return
+	}
+
+	config := params.BeaconConfig()
+	if finalized.Epoch < config.AltairForkEpoch {
+		return
+	}
+
+	syncAggregate, err := signed.Block().Body().SyncAggregate()
+	if err != nil || syncAggregate == nil {
+		return
+	}
+
+	// LightClientFinalityUpdate needs super majority
+	if syncAggregate.SyncCommitteeBits.Count()*3 < config.SyncCommitteeSize*2 {
+		return
+	}
+
+	_, err = s.sendLightClientFinalityUpdate(ctx, signed, postState)
+	if err != nil {
+		log.WithError(err).Error("Failed to send light client finality update")
+	} else {
+		s.lastPublishedLightClientEpoch = finalized.Epoch
+	}
+}
+
+// sendLightClientFinalityUpdate sends a light client finality update notification to the state feed.
+func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState) (int, error) {
+	// Get attested state
+	attestedRoot := signed.Block().ParentRoot()
+	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
+	if err != nil {
+		return 0, errors.Wrap(err, "could not get attested state")
+	}
+
+	// Get finalized block
+	var finalizedBlock interfaces.ReadOnlySignedBeaconBlock
+	finalizedCheckPoint := attestedState.FinalizedCheckpoint()
+	if finalizedCheckPoint != nil {
+		finalizedRoot := bytesutil.ToBytes32(finalizedCheckPoint.Root)
+		finalizedBlock, err = s.cfg.BeaconDB.Block(ctx, finalizedRoot)
+		if err != nil {
+			finalizedBlock = nil
+		}
+	}
+
+	update, err := NewLightClientFinalityUpdateFromBeaconState(
+		ctx,
+		postState,
+		signed,
+		attestedState,
+		finalizedBlock,
+	)
+
+	if err != nil {
+		return 0, errors.Wrap(err, "could not create light client update")
+	}
+
+	// Return the result
+	result := &ethpbv2.LightClientFinalityUpdateWithVersion{
+		Version: ethpbv2.Version(signed.Version()),
+		Data:    CreateLightClientFinalityUpdate(update),
+	}
+
+	// Send event
+	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+		Type: statefeed.LightClientFinalityUpdate,
+		Data: result,
+	}), nil
+}
+
+// sendLightClientOptimisticUpdate sends a light client optimistic update notification to the state feed.
+func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState) (int, error) {
+	// Get attested state
+	attestedRoot := signed.Block().ParentRoot()
+	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
+	if err != nil {
+		return 0, errors.Wrap(err, "could not get attested state")
+	}
+
+	update, err := NewLightClientOptimisticUpdateFromBeaconState(
+		ctx,
+		postState,
+		signed,
+		attestedState,
+	)
+
+	if err != nil {
+		return 0, errors.Wrap(err, "could not create light client update")
+	}
+
+	// Return the result
+	result := &ethpbv2.LightClientOptimisticUpdateWithVersion{
+		Version: ethpbv2.Version(signed.Version()),
+		Data:    CreateLightClientOptimisticUpdate(update),
+	}
+
+	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+		Type: statefeed.LightClientOptimisticUpdate,
+		Data: result,
+	}), nil
+}
+
+// updateCachesPostBlockProcessing updates the next slot cache and handles the epoch
+// boundary in order to compute the right proposer indices after processing
+// state transition. This function is called on late blocks while still locked,
+// before sending FCU to the engine.
+func (s *Service) updateCachesPostBlockProcessing(cfg *postBlockProcessConfig) error {
+	slot := cfg.postState.Slot()
+	if err := transition.UpdateNextSlotCache(cfg.ctx, cfg.blockRoot[:], cfg.postState); err != nil {
+		return errors.Wrap(err, "could not update next slot state cache")
+	}
+	if !slots.IsEpochEnd(slot) {
+		return nil
+	}
+	return s.handleEpochBoundary(cfg.ctx, slot, cfg.postState, cfg.blockRoot[:])
+}
+
+// handleSecondFCUCall handles a second call to FCU when syncing a new block.
+// This is useful when proposing in the next block and we want to defer the
+// computation of the next slot shuffling.
+func (s *Service) handleSecondFCUCall(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) {
+	if (fcuArgs.attributes == nil || fcuArgs.attributes.IsEmpty()) && cfg.headRoot == cfg.blockRoot {
+		go s.sendFCUWithAttributes(cfg, fcuArgs)
+	}
+}
+
+// reportProcessingTime reports the metric of how long it took to process the
+// current block
+func reportProcessingTime(startTime time.Time) {
+	onBlockProcessingTime.Observe(float64(time.Since(startTime).Milliseconds()))
+}
+
+// computePayloadAttributes modifies the passed FCU arguments to
+// contain the right payload attributes with the tracked proposer. It gets
+// called on blocks that arrive after the attestation voting window, or in a
+// background routine after syncing early blocks.
+func (s *Service) computePayloadAttributes(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) error {
+	if cfg.blockRoot == cfg.headRoot {
+		if err := s.updateCachesPostBlockProcessing(cfg); err != nil {
+			return err
+		}
+	}
+	fcuArgs.attributes = s.getPayloadAttribute(cfg.ctx, fcuArgs.headState, fcuArgs.proposingSlot, cfg.headRoot[:])
+	return nil
+}
+
 // getBlockPreState returns the pre state of an incoming block. It uses the parent root of the block
 // to retrieve the state in DB. It verifies the pre state's validity and the incoming block
 // is in the correct time window.
@@ -46,7 +299,7 @@ func (s *Service) getBlockPreState(ctx context.Context, b interfaces.ReadOnlyBea
 	}

 	// Verify block slot time is not from the future.
-	if err := slots.VerifyTime(uint64(s.genesisTime.Unix()), b.Slot(), params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
+	if err := slots.VerifyTime(uint64(s.genesisTime.Unix()), b.Slot(), params.BeaconConfig().MaximumGossipClockDisparityDuration()); err != nil {
 		return nil, err
 	}

--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
@@ -1,7 +1,6 @@
 package blockchain

 import (
-	"bytes"
 	"context"
 	"fmt"
 	"math/big"
@@ -17,6 +16,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/blocks"
 	"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/das"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db/filesystem"
 	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
@@ -40,7 +40,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	"github.com/prysmaticlabs/prysm/v4/testing/util"
 	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
-	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -69,7 +68,7 @@ func TestStore_OnBlockBatch(t *testing.T) {
 		require.NoError(t, err)
 		blks = append(blks, rwsb)
 	}
-	err := service.onBlockBatch(ctx, blks)
+	err := service.onBlockBatch(ctx, blks, &das.MockAvailabilityStore{})
 	require.NoError(t, err)
 	jcp := service.CurrentJustifiedCheckpt()
 	jroot := bytesutil.ToBytes32(jcp.Root)
@@ -99,7 +98,7 @@ func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
 		require.NoError(t, service.saveInitSyncBlock(ctx, rwsb.Root(), wsb))
 		blks = append(blks, rwsb)
 	}
-	require.NoError(t, service.onBlockBatch(ctx, blks))
+	require.NoError(t, service.onBlockBatch(ctx, blks, &das.MockAvailabilityStore{}))
 }

 func TestCachedPreState_CanGetFromStateSummary(t *testing.T) {
@@ -567,7 +566,7 @@ func TestOnBlock_CanFinalize_WithOnTick(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, r, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, r, postState, true))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, r, [32]byte{}, postState, true}))
 		require.NoError(t, service.updateJustificationOnBlock(ctx, preState, postState, currStoreJustifiedEpoch))
 		_, err = service.updateFinalizationOnBlock(ctx, preState, postState, currStoreFinalizedEpoch)
 		require.NoError(t, err)
@@ -615,7 +614,7 @@ func TestOnBlock_CanFinalize(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, r, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, r, postState, true))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, r, [32]byte{}, postState, true}))
 		require.NoError(t, service.updateJustificationOnBlock(ctx, preState, postState, currStoreJustifiedEpoch))
 		_, err = service.updateFinalizationOnBlock(ctx, preState, postState, currStoreFinalizedEpoch)
 		require.NoError(t, err)
@@ -641,7 +640,7 @@ func TestOnBlock_CanFinalize(t *testing.T) {

 func TestOnBlock_NilBlock(t *testing.T) {
 	service, tr := minimalTestService(t)
-	err := service.postBlockProcess(tr.ctx, nil, [32]byte{}, nil, true)
+	err := service.postBlockProcess(&postBlockProcessConfig{tr.ctx, nil, [32]byte{}, [32]byte{}, nil, true})
 	require.Equal(t, true, IsInvalidBlock(err))
 }

@@ -689,7 +688,7 @@ func TestOnBlock_CallNewPayloadAndForkchoiceUpdated(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, r, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, r, postState, false))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, r, [32]byte{}, postState, false}))
 		testState, err = service.cfg.StateGen.StateByRoot(ctx, r)
 		require.NoError(t, err)
 	}
@@ -895,7 +894,7 @@ func Test_validateMergeTransitionBlock(t *testing.T) {
 	cfg.TerminalBlockHash = params.BeaconConfig().ZeroHash
 	params.OverrideBeaconConfig(cfg)

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

 	aHash := common.BytesToHash([]byte("a"))
@@ -912,7 +911,6 @@ func Test_validateMergeTransitionBlock(t *testing.T) {
 			name:         "state older than Bellatrix, nil payload",
 			stateVersion: 1,
 			payload:      nil,
-			errString:    "attempted to wrap nil",
 		},
 		{
 			name:         "state older than Bellatrix, empty payload",
@@ -924,8 +922,10 @@ func Test_validateMergeTransitionBlock(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),
 			},
 		},
 		{
@@ -939,7 +939,6 @@ func Test_validateMergeTransitionBlock(t *testing.T) {
 			name:         "state is Bellatrix, nil payload",
 			stateVersion: 2,
 			payload:      nil,
-			errString:    "attempted to wrap nil",
 		},
 		{
 			name:         "state is Bellatrix, empty payload",
@@ -969,6 +968,7 @@ func Test_validateMergeTransitionBlock(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),
 					TransactionsRoot: make([]byte, fieldparams.RootLength),
@@ -1111,7 +1111,7 @@ func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 			postState, err := service.validateStateTransition(ctx, preState, wsb1)
 			require.NoError(t, err)
 			lock.Lock()
-			require.NoError(t, service.postBlockProcess(ctx, wsb1, r1, postState, true))
+			require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb1, r1, [32]byte{}, postState, true}))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1121,7 +1121,7 @@ func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 			postState, err := service.validateStateTransition(ctx, preState, wsb2)
 			require.NoError(t, err)
 			lock.Lock()
-			require.NoError(t, service.postBlockProcess(ctx, wsb2, r2, postState, true))
+			require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb2, r2, [32]byte{}, postState, true}))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1131,7 +1131,7 @@ func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 			postState, err := service.validateStateTransition(ctx, preState, wsb3)
 			require.NoError(t, err)
 			lock.Lock()
-			require.NoError(t, service.postBlockProcess(ctx, wsb3, r3, postState, true))
+			require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb3, r3, [32]byte{}, postState, true}))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1141,7 +1141,7 @@ func TestOnBlock_ProcessBlocksParallel(t *testing.T) {
 			postState, err := service.validateStateTransition(ctx, preState, wsb4)
 			require.NoError(t, err)
 			lock.Lock()
-			require.NoError(t, service.postBlockProcess(ctx, wsb4, r4, postState, true))
+			require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb4, r4, [32]byte{}, postState, true}))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1216,7 +1216,7 @@ func TestStore_NoViableHead_FCU(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
 	}

 	for i := 6; i < 12; i++ {
@@ -1234,7 +1234,7 @@ func TestStore_NoViableHead_FCU(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}

@@ -1253,7 +1253,7 @@ func TestStore_NoViableHead_FCU(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}
 	// Check that we haven't justified the second epoch yet
@@ -1275,7 +1275,7 @@ func TestStore_NoViableHead_FCU(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, firstInvalidRoot, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, firstInvalidRoot, postState, false)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, firstInvalidRoot, [32]byte{}, postState, false})
 	require.NoError(t, err)
 	jc = service.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	require.Equal(t, primitives.Epoch(2), jc.Epoch)
@@ -1303,7 +1303,7 @@ func TestStore_NoViableHead_FCU(t *testing.T) {
 	postState, err = service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, root, postState, false)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 	require.ErrorContains(t, "received an INVALID payload from execution engine", err)
 	// Check that forkchoice's head is the last invalid block imported. The
 	// store's headroot is the previous head (since the invalid block did
@@ -1332,7 +1332,7 @@ func TestStore_NoViableHead_FCU(t *testing.T) {
 	postState, err = service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, root, postState, true)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
 	require.NoError(t, err)
 	// Check the newly imported block is head, it justified the right
 	// checkpoint and the node is no longer optimistic
@@ -1394,7 +1394,7 @@ func TestStore_NoViableHead_NewPayload(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
 	}

 	for i := 6; i < 12; i++ {
@@ -1412,7 +1412,7 @@ func TestStore_NoViableHead_NewPayload(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}

@@ -1432,7 +1432,7 @@ func TestStore_NoViableHead_NewPayload(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}
 	// Check that we haven't justified the second epoch yet
@@ -1454,7 +1454,7 @@ func TestStore_NoViableHead_NewPayload(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, firstInvalidRoot, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, firstInvalidRoot, postState, false)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, firstInvalidRoot, [32]byte{}, postState, false})
 	require.NoError(t, err)
 	jc = service.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	require.Equal(t, primitives.Epoch(2), jc.Epoch)
@@ -1510,7 +1510,7 @@ func TestStore_NoViableHead_NewPayload(t *testing.T) {
 	postState, err = service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, root, postState, true)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
 	require.NoError(t, err)
 	// Check the newly imported block is head, it justified the right
 	// checkpoint and the node is no longer optimistic
@@ -1574,7 +1574,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
 	}

 	for i := 6; i < 12; i++ {
@@ -1593,7 +1593,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}

@@ -1612,7 +1612,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, lastValidRoot, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, lastValidRoot, postState, false)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, lastValidRoot, [32]byte{}, postState, false})
 	require.NoError(t, err)
 	// save the post state and the payload Hash of this block since it will
 	// be the LVH
@@ -1639,7 +1639,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, invalidRoots[i-13], wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, invalidRoots[i-13], postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, invalidRoots[i-13], [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}
 	// Check that we have justified the second epoch
@@ -1704,7 +1704,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 	postState, err = service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-	require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, true))
+	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true}))
 	// Check that the head is still INVALID and the node is still optimistic
 	require.Equal(t, invalidHeadRoot, service.cfg.ForkChoiceStore.CachedHeadRoot())
 	optimistic, err = service.IsOptimistic(ctx)
@@ -1727,7 +1727,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, true)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
 		require.NoError(t, err)
 		st, err = service.cfg.StateGen.StateByRoot(ctx, root)
 		require.NoError(t, err)
@@ -1753,7 +1753,7 @@ func TestStore_NoViableHead_Liveness(t *testing.T) {
 	postState, err = service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, root, postState, true)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
 	require.NoError(t, err)
 	require.Equal(t, root, service.cfg.ForkChoiceStore.CachedHeadRoot())
 	sjc = service.CurrentJustifiedCheckpt()
@@ -1809,7 +1809,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
 	}

 	for i := 6; i < 12; i++ {
@@ -1827,7 +1827,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		err = service.postBlockProcess(ctx, wsb, root, postState, false)
+		err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
 		require.NoError(t, err)
 	}

@@ -1846,7 +1846,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, lastValidRoot, wsb, postState))
-	err = service.postBlockProcess(ctx, wsb, lastValidRoot, postState, false)
+	err = service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, lastValidRoot, [32]byte{}, postState, false})
 	require.NoError(t, err)
 	// save the post state and the payload Hash of this block since it will
 	// be the LVH
@@ -1875,7 +1875,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 		postState, err := service.validateStateTransition(ctx, preState, wsb)
 		require.NoError(t, err)
 		require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
+		require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
 		require.NoError(t, service.updateJustificationOnBlock(ctx, preState, postState, currStoreJustifiedEpoch))
 		_, err = service.updateFinalizationOnBlock(ctx, preState, postState, currStoreFinalizedEpoch)
 		require.NoError(t, err)
@@ -1946,7 +1946,7 @@ func TestNoViableHead_Reboot(t *testing.T) {
 	rwsb, err := consensusblocks.NewROBlock(wsb)
 	require.NoError(t, err)
 	// We use onBlockBatch here because the valid chain is missing in forkchoice
-	require.NoError(t, service.onBlockBatch(ctx, []consensusblocks.ROBlock{rwsb}))
+	require.NoError(t, service.onBlockBatch(ctx, []consensusblocks.ROBlock{rwsb}, &das.MockAvailabilityStore{}))
 	// Check that the head is now VALID and the node is not optimistic
 	require.Equal(t, genesisRoot, service.ensureRootNotZeros(service.cfg.ForkChoiceStore.CachedHeadRoot()))
 	headRoot, err = service.HeadRoot(ctx)
@@ -1990,7 +1990,7 @@ func TestOnBlock_HandleBlockAttestations(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, root, wsb, postState))
-	require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
+	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))

 	st, err = service.HeadState(ctx)
 	require.NoError(t, err)
@@ -2045,76 +2045,10 @@ func TestFillMissingBlockPayloadId_PrepareAllPayloads(t *testing.T) {
 // Helper function to simulate the block being on time or delayed for proposer
 // boost. It alters the genesisTime tracked by the store.
 func driftGenesisTime(s *Service, slot, delay int64) {
-	offset := slot*int64(params.BeaconConfig().SecondsPerSlot) - delay
-	s.SetGenesisTime(time.Unix(time.Now().Unix()-offset, 0))
-}
-
-func Test_commitmentsToCheck(t *testing.T) {
-	windowSlots, err := slots.EpochEnd(params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest)
-	require.NoError(t, err)
-	commits := [][]byte{
-		bytesutil.PadTo([]byte("a"), 48),
-		bytesutil.PadTo([]byte("b"), 48),
-		bytesutil.PadTo([]byte("c"), 48),
-		bytesutil.PadTo([]byte("d"), 48),
-	}
-	cases := []struct {
-		name    string
-		commits [][]byte
-		block   func(*testing.T) consensusblocks.ROBlock
-		slot    primitives.Slot
-	}{
-		{
-			name: "pre deneb",
-			block: func(t *testing.T) consensusblocks.ROBlock {
-				bb := util.NewBeaconBlockBellatrix()
-				sb, err := consensusblocks.NewSignedBeaconBlock(bb)
-				require.NoError(t, err)
-				rb, err := consensusblocks.NewROBlock(sb)
-				require.NoError(t, err)
-				return rb
-			},
-		},
-		{
-			name: "commitments within da",
-			block: func(t *testing.T) consensusblocks.ROBlock {
-				d := util.NewBeaconBlockDeneb()
-				d.Block.Body.BlobKzgCommitments = commits
-				d.Block.Slot = 100
-				sb, err := consensusblocks.NewSignedBeaconBlock(d)
-				require.NoError(t, err)
-				rb, err := consensusblocks.NewROBlock(sb)
-				require.NoError(t, err)
-				return rb
-			},
-			commits: commits,
-			slot:    100,
-		},
-		{
-			name: "commitments outside da",
-			block: func(t *testing.T) consensusblocks.ROBlock {
-				d := util.NewBeaconBlockDeneb()
-				// block is from slot 0, "current slot" is window size +1 (so outside the window)
-				d.Block.Body.BlobKzgCommitments = commits
-				sb, err := consensusblocks.NewSignedBeaconBlock(d)
-				require.NoError(t, err)
-				rb, err := consensusblocks.NewROBlock(sb)
-				require.NoError(t, err)
-				return rb
-			},
-			slot: windowSlots + 1,
-		},
-	}
-	for _, c := range cases {
-		t.Run(c.name, func(t *testing.T) {
-			b := c.block(t)
-			co := commitmentsToCheck(b, c.slot)
-			require.Equal(t, len(c.commits), len(co))
-			for i := 0; i < len(c.commits); i++ {
-				require.Equal(t, true, bytes.Equal(c.commits[i], co[i]))
-			}
-		})
-	}
+	offset := slot*int64(params.BeaconConfig().SecondsPerSlot) + delay
+	newTime := time.Unix(time.Now().Unix()-offset, 0)
+	s.SetGenesisTime(newTime)
+	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(newTime.Unix()))
 }

 func TestMissingIndices(t *testing.T) {
@@ -2197,6 +2131,35 @@ func TestMissingIndices(t *testing.T) {
 	}
 }

+func Test_getFCUArgs(t *testing.T) {
+	s, tr := minimalTestService(t)
+	ctx := tr.ctx
+	st, keys := util.DeterministicGenesisState(t, 64)
+	b, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	require.NoError(t, err)
+	wsb, err := consensusblocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+
+	cfg := &postBlockProcessConfig{
+		ctx:            ctx,
+		signed:         wsb,
+		blockRoot:      [32]byte{'a'},
+		postState:      st,
+		isValidPayload: true,
+	}
+	// error branch
+	fcuArgs := &fcuConfig{}
+	err = s.getFCUArgs(cfg, fcuArgs)
+	require.ErrorContains(t, "block does not exist", err)
+
+	// canonical branch
+	cfg.headRoot = cfg.blockRoot
+	fcuArgs = &fcuConfig{}
+	err = s.getFCUArgs(cfg, fcuArgs)
+	require.NoError(t, err)
+	require.Equal(t, cfg.blockRoot, fcuArgs.headRoot)
+}
+
 func fakeCommitments(n int) [][]byte {
 	f := make([][]byte, n)
 	for i := range f {
--- a/beacon-chain/blockchain/receive_attestation.go
+++ b/beacon-chain/blockchain/receive_attestation.go
@@ -9,7 +9,6 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
 	"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/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
@@ -53,15 +52,11 @@ func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Chec

 // VerifyLmdFfgConsistency verifies that attestation's LMD and FFG votes are consistency to each other.
 func (s *Service) VerifyLmdFfgConsistency(ctx context.Context, a *ethpb.Attestation) error {
-	targetSlot, err := slots.EpochStart(a.Data.Target.Epoch)
+	r, err := s.TargetRootForEpoch([32]byte(a.Data.BeaconBlockRoot), a.Data.Target.Epoch)
 	if err != nil {
 		return err
 	}
-	r, err := s.Ancestor(ctx, a.Data.BeaconBlockRoot, targetSlot)
-	if err != nil {
-		return err
-	}
-	if !bytes.Equal(a.Data.Target.Root, r) {
+	if !bytes.Equal(a.Data.Target.Root, r[:]) {
 		return fmt.Errorf("FFG and LMD votes are not consistent, block root: %#x, target root: %#x, canonical target root: %#x", a.Data.BeaconBlockRoot, a.Data.Target.Root, r)
 	}
 	return nil
@@ -125,36 +120,44 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)
 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()
 	// This function is only called at 10 seconds or 0 seconds into the slot
-	disparity := params.BeaconNetworkConfig().MaximumGossipClockDisparity
-	if !features.Get().DisableReorgLateBlocks {
-		disparity += reorgLateBlockCountAttestations
-	}
+	disparity := params.BeaconConfig().MaximumGossipClockDisparityDuration()
+	disparity += reorgLateBlockCountAttestations
+
 	s.processAttestations(ctx, disparity)

 	processAttsElapsedTime.Observe(float64(time.Since(start).Milliseconds()))

 	start = time.Now()
+	// return early if we haven't changed head
 	newHeadRoot, err := s.cfg.ForkChoiceStore.Head(ctx)
 	if err != nil {
 		log.WithError(err).Error("Could not compute head from new attestations")
-		// Fallback to our current head root in the event of a failure.
-		s.headLock.RLock()
-		newHeadRoot = s.headRoot()
-		s.headLock.RUnlock()
+		return
+	}
+	if !s.isNewHead(newHeadRoot) {
+		return
+	}
+	log.WithField("newHeadRoot", fmt.Sprintf("%#x", newHeadRoot)).Debug("Head changed due to attestations")
+	headState, headBlock, err := s.getStateAndBlock(ctx, newHeadRoot)
+	if err != nil {
+		log.WithError(err).Error("could not get head block")
+		return
 	}
 	newAttHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
-
-	changed, err := s.forkchoiceUpdateWithExecution(s.ctx, newHeadRoot, proposingSlot)
-	if err != nil {
-		log.WithError(err).Error("could not update forkchoice")
+	fcuArgs := &fcuConfig{
+		headState:     headState,
+		headRoot:      newHeadRoot,
+		headBlock:     headBlock,
+		proposingSlot: proposingSlot,
 	}
-	if changed {
-		s.headLock.RLock()
-		log.WithFields(logrus.Fields{
-			"oldHeadRoot": fmt.Sprintf("%#x", s.headRoot()),
-			"newHeadRoot": fmt.Sprintf("%#x", newHeadRoot),
-		}).Debug("Head changed due to attestations")
-		s.headLock.RUnlock()
+	if s.inRegularSync() {
+		fcuArgs.attributes = s.getPayloadAttribute(ctx, headState, proposingSlot, newHeadRoot[:])
+	}
+	if fcuArgs.attributes != nil && s.shouldOverrideFCU(newHeadRoot, proposingSlot) {
+		return
+	}
+	if err := s.forkchoiceUpdateWithExecution(s.ctx, fcuArgs); err != nil {
+		log.WithError(err).Error("could not update forkchoice")
 	}
 }

--- a/beacon-chain/blockchain/receive_attestation_test.go
+++ b/beacon-chain/blockchain/receive_attestation_test.go
@@ -36,50 +36,28 @@ func TestAttestationCheckPtState_FarFutureSlot(t *testing.T) {
 	require.ErrorContains(t, "exceeds max allowed value relative to the local clock", err)
 }

-func TestVerifyLMDFFGConsistent_NotOK(t *testing.T) {
+func TestVerifyLMDFFGConsistent(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx := tr.ctx

-	b32 := util.NewBeaconBlock()
-	b32.Block.Slot = 32
-	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b32)
-	r32, err := b32.Block.HashTreeRoot()
+	f := service.cfg.ForkChoiceStore
+	fc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	state, r32, err := prepareForkchoiceState(ctx, 32, [32]byte{'a'}, params.BeaconConfig().ZeroHash, params.BeaconConfig().ZeroHash, fc, fc)
 	require.NoError(t, err)
-	b33 := util.NewBeaconBlock()
-	b33.Block.Slot = 33
-	b33.Block.ParentRoot = r32[:]
-	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b33)
-	r33, err := b33.Block.HashTreeRoot()
+	require.NoError(t, f.InsertNode(ctx, state, r32))
+
+	state, r33, err := prepareForkchoiceState(ctx, 33, [32]byte{'b'}, r32, params.BeaconConfig().ZeroHash, fc, fc)
 	require.NoError(t, err)
+	require.NoError(t, f.InsertNode(ctx, state, r33))

 	wanted := "FFG and LMD votes are not consistent"
 	a := util.NewAttestation()
 	a.Data.Target.Epoch = 1
-	a.Data.Target.Root = []byte{'a'}
+	a.Data.Target.Root = []byte{'c'}
 	a.Data.BeaconBlockRoot = r33[:]
 	require.ErrorContains(t, wanted, service.VerifyLmdFfgConsistency(context.Background(), a))
-}

-func TestVerifyLMDFFGConsistent_OK(t *testing.T) {
-	service, tr := minimalTestService(t)
-	ctx := tr.ctx
-
-	b32 := util.NewBeaconBlock()
-	b32.Block.Slot = 32
-	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b32)
-	r32, err := b32.Block.HashTreeRoot()
-	require.NoError(t, err)
-	b33 := util.NewBeaconBlock()
-	b33.Block.Slot = 33
-	b33.Block.ParentRoot = r32[:]
-	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b33)
-	r33, err := b33.Block.HashTreeRoot()
-	require.NoError(t, err)
-
-	a := util.NewAttestation()
-	a.Data.Target.Epoch = 1
 	a.Data.Target.Root = r32[:]
-	a.Data.BeaconBlockRoot = r33[:]
 	err = service.VerifyLmdFfgConsistency(context.Background(), a)
 	require.NoError(t, err, "Could not verify LMD and FFG votes to be consistent")
 }
@@ -134,7 +112,7 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, tRoot, wsb, postState))
-	require.NoError(t, service.postBlockProcess(ctx, wsb, tRoot, postState, false))
+	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, tRoot, [32]byte{}, postState, false}))
 	copied, err = service.cfg.StateGen.StateByRoot(ctx, tRoot)
 	require.NoError(t, err)
 	require.Equal(t, 2, fcs.NodeCount())
@@ -190,7 +168,7 @@ func TestService_UpdateHead_NoAtts(t *testing.T) {
 	postState, err := service.validateStateTransition(ctx, preState, wsb)
 	require.NoError(t, err)
 	require.NoError(t, service.savePostStateInfo(ctx, tRoot, wsb, postState))
-	require.NoError(t, service.postBlockProcess(ctx, wsb, tRoot, postState, false))
+	require.NoError(t, service.postBlockProcess(&postBlockProcessConfig{ctx, wsb, tRoot, [32]byte{}, postState, false}))
 	require.Equal(t, 2, fcs.NodeCount())
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
 	require.Equal(t, tRoot, service.head.root)
--- a/beacon-chain/blockchain/receive_blob.go
+++ b/beacon-chain/blockchain/receive_blob.go
@@ -7,7 +7,7 @@ import (
 )

 // SendNewBlobEvent sends a message to the BlobNotifier channel that the blob
-// for the blocroot `root` is ready in the database
+// for the block root `root` is ready in the database
 func (s *Service) sendNewBlobEvent(root [32]byte, index uint64) {
 	s.blobNotifiers.notifyIndex(root, index)
 }
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -12,6 +12,7 @@ import (
 	"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/das"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/config/features"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
@@ -33,8 +34,8 @@ var epochsSinceFinalitySaveHotStateDB = primitives.Epoch(100)

 // BlockReceiver interface defines the methods of chain service for receiving and processing new blocks.
 type BlockReceiver interface {
-	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error
-	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock) error
+	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error
+	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityStore) error
 	HasBlock(ctx context.Context, root [32]byte) bool
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 	BlockBeingSynced([32]byte) bool
@@ -56,7 +57,7 @@ type SlashingReceiver interface {
 //  1. Validate block, apply state transition and update checkpoints
 //  2. Apply fork choice to the processed block
 //  3. Save latest head info
-func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error {
+func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlock")
 	defer span.End()
 	// Return early if the block has been synced
@@ -72,6 +73,10 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err != nil {
 		return err
 	}
+	rob, err := blocks.NewROBlockWithRoot(block, blockRoot)
+	if err != nil {
+		return err
+	}

 	preState, err := s.getBlockPreState(ctx, blockCopy.Block())
 	if err != nil {
@@ -106,21 +111,41 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err := eg.Wait(); err != nil {
 		return err
 	}
-	if err := s.isDataAvailable(ctx, blockRoot, blockCopy); err != nil {
-		return errors.Wrap(err, "could not validate blob data availability")
+	daStartTime := time.Now()
+	if avs != nil {
+		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), rob); err != nil {
+			return errors.Wrap(err, "could not validate blob data availability (AvailabilityStore.IsDataAvailable)")
+		}
+	} else {
+		if err := s.isDataAvailable(ctx, blockRoot, blockCopy); err != nil {
+			return errors.Wrap(err, "could not validate blob data availability")
+		}
 	}
+	daWaitedTime := time.Since(daStartTime)
+	dataAvailWaitedTime.Observe(float64(daWaitedTime.Milliseconds()))
+
+	// Defragment the state before continuing block processing.
+	s.defragmentState(postState)
+
 	// The rest of block processing takes a lock on forkchoice.
 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()
 	if err := s.savePostStateInfo(ctx, blockRoot, blockCopy, postState); err != nil {
 		return errors.Wrap(err, "could not save post state info")
 	}
-	if err := s.postBlockProcess(ctx, blockCopy, blockRoot, postState, isValidPayload); err != nil {
+	args := &postBlockProcessConfig{
+		ctx:            ctx,
+		signed:         blockCopy,
+		blockRoot:      blockRoot,
+		postState:      postState,
+		isValidPayload: isValidPayload,
+	}
+	if err := s.postBlockProcess(args); err != nil {
 		err := errors.Wrap(err, "could not process block")
 		tracing.AnnotateError(span, err)
 		return err
 	}
-	if coreTime.CurrentEpoch(postState) > currentEpoch {
+	if coreTime.CurrentEpoch(postState) > currentEpoch && s.cfg.ForkChoiceStore.IsCanonical(blockRoot) {
 		headSt, err := s.HeadState(ctx)
 		if err != nil {
 			return errors.Wrap(err, "could not get head state")
@@ -171,7 +196,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	// Log block sync status.
 	cp = s.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	justified := &ethpb.Checkpoint{Epoch: cp.Epoch, Root: bytesutil.SafeCopyBytes(cp.Root[:])}
-	if err := logBlockSyncStatus(blockCopy.Block(), blockRoot, justified, finalized, receivedTime, uint64(s.genesisTime.Unix())); err != nil {
+	if err := logBlockSyncStatus(blockCopy.Block(), blockRoot, justified, finalized, receivedTime, uint64(s.genesisTime.Unix()), daWaitedTime); err != nil {
 		log.WithError(err).Error("Unable to log block sync status")
 	}
 	// Log payload data
@@ -183,7 +208,8 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		log.WithError(err).Error("Unable to log state transition data")
 	}

-	chainServiceProcessingTime.Observe(float64(time.Since(receivedTime).Milliseconds()))
+	timeWithoutDaWait := time.Since(receivedTime) - daWaitedTime
+	chainServiceProcessingTime.Observe(float64(timeWithoutDaWait.Milliseconds()))

 	return nil
 }
@@ -191,7 +217,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 // ReceiveBlockBatch processes the whole block batch at once, assuming the block batch is linear ,transitioning
 // the state, performing batch verification of all collected signatures and then performing the appropriate
 // actions for a block post-transition.
-func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock) error {
+func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityStore) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlockBatch")
 	defer span.End()

@@ -199,7 +225,7 @@ func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock
 	defer s.cfg.ForkChoiceStore.Unlock()

 	// Apply state transition on the incoming newly received block batches, one by one.
-	if err := s.onBlockBatch(ctx, blocks); err != nil {
+	if err := s.onBlockBatch(ctx, blocks, avs); err != nil {
 		err := errors.Wrap(err, "could not process block in batch")
 		tracing.AnnotateError(span, err)
 		return err
--- a/beacon-chain/blockchain/receive_block_test.go
+++ b/beacon-chain/blockchain/receive_block_test.go
@@ -7,6 +7,8 @@ import (
 	"time"

 	blockchainTesting "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/das"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/voluntaryexits"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
@@ -130,7 +132,9 @@ func TestService_ReceiveBlock(t *testing.T) {
 			s, tr := minimalTestService(t,
 				WithFinalizedStateAtStartUp(genesis),
 				WithExitPool(voluntaryexits.NewPool()),
-				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}))
+				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
+				WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
+			)

 			beaconDB := tr.db
 			genesisBlockRoot := bytesutil.ToBytes32(nil)
@@ -143,7 +147,7 @@ func TestService_ReceiveBlock(t *testing.T) {
 			require.NoError(t, err)
 			wsb, err := blocks.NewSignedBeaconBlock(tt.args.block)
 			require.NoError(t, err)
-			err = s.ReceiveBlock(ctx, wsb, root)
+			err = s.ReceiveBlock(ctx, wsb, root, nil)
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
@@ -176,7 +180,7 @@ func TestService_ReceiveBlockUpdateHead(t *testing.T) {
 	go func() {
 		wsb, err := blocks.NewSignedBeaconBlock(b)
 		require.NoError(t, err)
-		require.NoError(t, s.ReceiveBlock(ctx, wsb, root))
+		require.NoError(t, s.ReceiveBlock(ctx, wsb, root, nil))
 		wg.Done()
 	}()
 	wg.Wait()
@@ -240,7 +244,7 @@ func TestService_ReceiveBlockBatch(t *testing.T) {
 			require.NoError(t, err)
 			rwsb, err := blocks.NewROBlock(wsb)
 			require.NoError(t, err)
-			err = s.ReceiveBlockBatch(ctx, []blocks.ROBlock{rwsb})
+			err = s.ReceiveBlockBatch(ctx, []blocks.ROBlock{rwsb}, &das.MockAvailabilityStore{})
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -11,6 +11,8 @@ import (
 	"time"

 	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+
 	"github.com/prysmaticlabs/prysm/v4/async/event"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/kzg"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
@@ -37,34 +39,35 @@ import (
 	"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"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"go.opencensus.io/trace"
 )

 // Service represents a service that handles the internal
 // logic of managing the full PoS beacon chain.
 type Service struct {
-	cfg                  *config
-	ctx                  context.Context
-	cancel               context.CancelFunc
-	genesisTime          time.Time
-	head                 *head
-	headLock             sync.RWMutex
-	originBlockRoot      [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
-	boundaryRoots        [][32]byte
-	checkpointStateCache *cache.CheckpointStateCache
-	initSyncBlocks       map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
-	initSyncBlocksLock   sync.RWMutex
-	wsVerifier           *WeakSubjectivityVerifier
-	clockSetter          startup.ClockSetter
-	clockWaiter          startup.ClockWaiter
-	syncComplete         chan struct{}
-	blobNotifiers        *blobNotifierMap
-	blockBeingSynced     *currentlySyncingBlock
-	blobStorage          *filesystem.BlobStorage
+	cfg                           *config
+	ctx                           context.Context
+	cancel                        context.CancelFunc
+	genesisTime                   time.Time
+	head                          *head
+	headLock                      sync.RWMutex
+	originBlockRoot               [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
+	boundaryRoots                 [][32]byte
+	checkpointStateCache          *cache.CheckpointStateCache
+	initSyncBlocks                map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
+	initSyncBlocksLock            sync.RWMutex
+	wsVerifier                    *WeakSubjectivityVerifier
+	clockSetter                   startup.ClockSetter
+	clockWaiter                   startup.ClockWaiter
+	syncComplete                  chan struct{}
+	blobNotifiers                 *blobNotifierMap
+	blockBeingSynced              *currentlySyncingBlock
+	blobStorage                   *filesystem.BlobStorage
+	lastPublishedLightClientEpoch primitives.Epoch
 }

 // config options for the service.
@@ -73,7 +76,8 @@ type config struct {
 	ChainStartFetcher       execution.ChainStartFetcher
 	BeaconDB                db.HeadAccessDatabase
 	DepositCache            cache.DepositCache
-	ProposerSlotIndexCache  *cache.ProposerPayloadIDsCache
+	PayloadIDCache          *cache.PayloadIDCache
+	TrackedValidatorsCache  *cache.TrackedValidatorsCache
 	AttPool                 attestations.Pool
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
@@ -89,6 +93,13 @@ type config struct {
 	BlockFetcher            execution.POWBlockFetcher
 	FinalizedStateAtStartUp state.BeaconState
 	ExecutionEngineCaller   execution.EngineCaller
+	SyncChecker             Checker
+}
+
+// Checker is an interface used to determine if a node is in initial sync
+// or regular sync.
+type Checker interface {
+	Synced() bool
 }

 var ErrMissingClockSetter = errors.New("blockchain Service initialized without a startup.ClockSetter")
@@ -167,7 +178,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 		checkpointStateCache: cache.NewCheckpointStateCache(),
 		initSyncBlocks:       make(map[[32]byte]interfaces.ReadOnlySignedBeaconBlock),
 		blobNotifiers:        bn,
-		cfg:                  &config{ProposerSlotIndexCache: cache.NewProposerPayloadIDsCache()},
+		cfg:                  &config{},
 		blockBeingSynced:     &currentlySyncingBlock{roots: make(map[[32]byte]struct{})},
 	}
 	for _, opt := range opts {
--- a/beacon-chain/blockchain/service_test.go
+++ b/beacon-chain/blockchain/service_test.go
@@ -100,7 +100,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		WithForkChoiceStore(fc),
 		WithAttestationService(attService),
 		WithStateGen(stateGen),
-		WithProposerIdsCache(cache.NewProposerPayloadIDsCache()),
+		WithPayloadIDCache(cache.NewPayloadIDCache()),
 		WithClockSynchronizer(startup.NewClockSynchronizer()),
 	}

--- a/beacon-chain/blockchain/setup_test.go
+++ b/beacon-chain/blockchain/setup_test.go
@@ -6,9 +6,12 @@ import (
 	"testing"

 	"github.com/prysmaticlabs/prysm/v4/async/event"
+	mock "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache/depositcache"
 	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"
 	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
@@ -114,6 +117,9 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithAttestationService(req.attSrv),
 		WithBLSToExecPool(req.blsPool),
 		WithDepositCache(dc),
+		WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
+		WithSyncChecker(mock.MockChecker{}),
 	}
 	// append the variadic opts so they override the defaults by being processed afterwards
 	opts = append(defOpts, opts...)
--- a/beacon-chain/blockchain/testing/BUILD.bazel
+++ b/beacon-chain/blockchain/testing/BUILD.bazel
@@ -17,6 +17,7 @@ go_library(
        "//beacon-chain/core/feed/operation:go_default_library",
        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
        "//beacon-chain/forkchoice:go_default_library",
        "//beacon-chain/state:go_default_library",
--- a/beacon-chain/blockchain/testing/mock.go
+++ b/beacon-chain/blockchain/testing/mock.go
@@ -16,6 +16,7 @@ import (
 	opfeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/operation"
 	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/das"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
@@ -73,6 +74,7 @@ type ChainService struct {
 	BlockSlot                   primitives.Slot
 	SyncingRoot                 [32]byte
 	Blobs                       []blocks.VerifiedROBlob
+	TargetRoot                  [32]byte
 }

 func (s *ChainService) Ancestor(ctx context.Context, root []byte, slot primitives.Slot) ([]byte, error) {
@@ -178,6 +180,14 @@ func (mon *MockOperationNotifier) OperationFeed() *event.Feed {
 	return mon.feed
 }

+// MockChecker is a mock sync checker.
+type MockChecker struct{}
+
+// Synced returns true.
+func (_ MockChecker) Synced() bool {
+	return true
+}
+
 // ReceiveBlockInitialSync mocks ReceiveBlockInitialSync method in chain service.
 func (s *ChainService) ReceiveBlockInitialSync(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, _ [32]byte) error {
 	if s.State == nil {
@@ -207,7 +217,7 @@ func (s *ChainService) ReceiveBlockInitialSync(ctx context.Context, block interf
 }

 // ReceiveBlockBatch processes blocks in batches from initial-sync.
-func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBlock) error {
+func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBlock, _ das.AvailabilityStore) error {
 	if s.State == nil {
 		return ErrNilState
 	}
@@ -237,7 +247,7 @@ func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBl
 }

 // ReceiveBlock mocks ReceiveBlock method in chain service.
-func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, _ [32]byte) error {
+func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, _ [32]byte, _ das.AvailabilityStore) error {
 	if s.ReceiveBlockMockErr != nil {
 		return s.ReceiveBlockMockErr
 	}
@@ -319,7 +329,7 @@ func (s *ChainService) PreviousJustifiedCheckpt() *ethpb.Checkpoint {
 }

 // ReceiveAttestation mocks ReceiveAttestation method in chain service.
-func (_ *ChainService) ReceiveAttestation(_ context.Context, _ *ethpb.Attestation) error {
+func (*ChainService) ReceiveAttestation(_ context.Context, _ *ethpb.Attestation) error {
 	return nil
 }

@@ -399,12 +409,12 @@ func (s *ChainService) RecentBlockSlot([32]byte) (primitives.Slot, error) {
 }

 // HeadGenesisValidatorsRoot mocks HeadGenesisValidatorsRoot method in chain service.
-func (_ *ChainService) HeadGenesisValidatorsRoot() [32]byte {
+func (*ChainService) HeadGenesisValidatorsRoot() [32]byte {
 	return [32]byte{}
 }

 // VerifyLmdFfgConsistency mocks VerifyLmdFfgConsistency and always returns nil.
-func (_ *ChainService) VerifyLmdFfgConsistency(_ context.Context, a *ethpb.Attestation) error {
+func (*ChainService) VerifyLmdFfgConsistency(_ context.Context, a *ethpb.Attestation) error {
 	if !bytes.Equal(a.Data.BeaconBlockRoot, a.Data.Target.Root) {
 		return errors.New("LMD and FFG miss matched")
 	}
@@ -412,7 +422,7 @@ func (_ *ChainService) VerifyLmdFfgConsistency(_ context.Context, a *ethpb.Attes
 }

 // ChainHeads mocks ChainHeads and always return nil.
-func (_ *ChainService) ChainHeads() ([][32]byte, []primitives.Slot) {
+func (*ChainService) ChainHeads() ([][32]byte, []primitives.Slot) {
 	return [][32]byte{
 			bytesutil.ToBytes32(bytesutil.PadTo([]byte("foo"), 32)),
 			bytesutil.ToBytes32(bytesutil.PadTo([]byte("bar"), 32)),
@@ -421,7 +431,7 @@ func (_ *ChainService) ChainHeads() ([][32]byte, []primitives.Slot) {
 }

 // HeadPublicKeyToValidatorIndex mocks HeadPublicKeyToValidatorIndex and always return 0 and true.
-func (_ *ChainService) HeadPublicKeyToValidatorIndex(_ [fieldparams.BLSPubkeyLength]byte) (primitives.ValidatorIndex, bool) {
+func (*ChainService) HeadPublicKeyToValidatorIndex(_ [fieldparams.BLSPubkeyLength]byte) (primitives.ValidatorIndex, bool) {
 	return 0, true
 }

@@ -485,7 +495,7 @@ func (s *ChainService) UpdateHead(ctx context.Context, slot primitives.Slot) {
 }

 // ReceiveAttesterSlashing mocks the same method in the chain service.
-func (s *ChainService) ReceiveAttesterSlashing(context.Context, *ethpb.AttesterSlashing) {}
+func (*ChainService) ReceiveAttesterSlashing(context.Context, *ethpb.AttesterSlashing) {}

 // IsFinalized mocks the same method in the chain service.
 func (s *ChainService) IsFinalized(_ context.Context, blockRoot [32]byte) bool {
@@ -598,12 +608,12 @@ func (s *ChainService) ProposerBoost() [32]byte {
 }

 // FinalizedBlockHash mocks the same method in the chain service
-func (s *ChainService) FinalizedBlockHash() [32]byte {
+func (*ChainService) FinalizedBlockHash() [32]byte {
 	return [32]byte{}
 }

 // UnrealizedJustifiedPayloadBlockHash mocks the same method in the chain service
-func (s *ChainService) UnrealizedJustifiedPayloadBlockHash() [32]byte {
+func (*ChainService) UnrealizedJustifiedPayloadBlockHash() [32]byte {
 	return [32]byte{}
 }

@@ -617,3 +627,8 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 	c.Blobs = append(c.Blobs, b)
 	return nil
 }
+
+// TargetRootForEpoch mocks the same method in the chain service
+func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
+	return c.TargetRoot, nil
+}
--- a/beacon-chain/blockchain/tracked_proposer.go
+++ b/beacon-chain/blockchain/tracked_proposer.go
@@ -0,0 +1,27 @@
+package blockchain
+
+import (
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+)
+
+// trackedProposer returns whether the beacon node was informed, via the
+// validators/prepare_proposer endpoint, of the proposer at the given slot.
+// It only returns true if the tracked proposer is present and active.
+func (s *Service) trackedProposer(st state.ReadOnlyBeaconState, slot primitives.Slot) (cache.TrackedValidator, bool) {
+	if features.Get().PrepareAllPayloads {
+		return cache.TrackedValidator{Active: true}, true
+	}
+	id, err := helpers.BeaconProposerIndexAtSlot(s.ctx, st, slot)
+	if err != nil {
+		return cache.TrackedValidator{}, false
+	}
+	val, ok := s.cfg.TrackedValidatorsCache.Validator(id)
+	if !ok {
+		return cache.TrackedValidator{}, false
+	}
+	return val, val.Active
+}
--- a/beacon-chain/builder/BUILD.bazel
+++ b/beacon-chain/builder/BUILD.bazel
@@ -15,7 +15,6 @@ go_library(
        "//beacon-chain/cache:go_default_library",
        "//beacon-chain/db:go_default_library",
        "//cmd/beacon-chain/flags:go_default_library",
-        "//config/fieldparams:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
--- a/beacon-chain/builder/service.go
+++ b/beacon-chain/builder/service.go
@@ -2,7 +2,6 @@ package builder

 import (
 	"context"
-	"fmt"
 	"reflect"
 	"time"

@@ -11,7 +10,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
-	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
@@ -27,7 +25,7 @@ var ErrNoBuilder = errors.New("builder endpoint not configured")

 // BlockBuilder defines the interface for interacting with the block builder
 type BlockBuilder interface {
-	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error)
 	RegisterValidator(ctx context.Context, reg []*ethpb.SignedValidatorRegistrationV1) error
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
@@ -90,7 +88,7 @@ func (s *Service) Stop() error {
 }

 // SubmitBlindedBlock submits a blinded block to the builder relay network.
-func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlock")
 	defer span.End()
 	start := time.Now()
@@ -100,11 +98,8 @@ func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlyS
 	if s.c == nil {
 		return nil, nil, ErrNoBuilder
 	}
-	if uint64(len(blobs)) > fieldparams.MaxBlobsPerBlock {
-		return nil, nil, fmt.Errorf("blob count %d beyond max limit of %d", len(blobs), fieldparams.MaxBlobsPerBlock)
-	}

-	return s.c.SubmitBlindedBlock(ctx, b, blobs)
+	return s.c.SubmitBlindedBlock(ctx, b)
 }

 // GetHeader retrieves the header for a given slot and parent hash from the builder relay network.
--- a/beacon-chain/builder/service_test.go
+++ b/beacon-chain/builder/service_test.go
@@ -62,7 +62,7 @@ func Test_BuilderMethodsWithouClient(t *testing.T) {
 	_, err = s.GetHeader(context.Background(), 0, [32]byte{}, [48]byte{})
 	assert.ErrorContains(t, ErrNoBuilder.Error(), err)

-	_, _, err = s.SubmitBlindedBlock(context.Background(), nil, nil)
+	_, _, err = s.SubmitBlindedBlock(context.Background(), nil)
 	assert.ErrorContains(t, ErrNoBuilder.Error(), err)

 	err = s.RegisterValidator(context.Background(), nil)
--- a/beacon-chain/builder/testing/mock.go
+++ b/beacon-chain/builder/testing/mock.go
@@ -2,6 +2,7 @@ package testing

 import (
 	"context"
+	"math/big"

 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/api/client/builder"
@@ -45,7 +46,7 @@ func (s *MockBuilderService) Configured() bool {
 }

 // SubmitBlindedBlock for mocking.
-func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock, _ []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	switch b.Version() {
 	case version.Bellatrix:
 		w, err := blocks.WrappedExecutionPayload(s.Payload)
@@ -54,13 +55,13 @@ func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.
 		}
 		return w, nil, s.ErrSubmitBlindedBlock
 	case version.Capella:
-		w, err := blocks.WrappedExecutionPayloadCapella(s.PayloadCapella, 0)
+		w, err := blocks.WrappedExecutionPayloadCapella(s.PayloadCapella, big.NewInt(0))
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "could not wrap capella payload")
 		}
 		return w, nil, s.ErrSubmitBlindedBlock
 	case version.Deneb:
-		w, err := blocks.WrappedExecutionPayloadDeneb(s.PayloadDeneb, 0)
+		w, err := blocks.WrappedExecutionPayloadDeneb(s.PayloadDeneb, big.NewInt(0))
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "could not wrap deneb payload")
 		}
--- a/beacon-chain/cache/BUILD.bazel
+++ b/beacon-chain/cache/BUILD.bazel
@@ -25,6 +25,7 @@ go_library(
        "sync_committee_disabled.go",  # keep
        "sync_committee_head_state.go",
        "sync_subnet_ids.go",
+        "tracked_validators.go",
    ],
    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/cache",
    visibility = [
@@ -33,6 +34,7 @@ go_library(
        "//tools:__subpackages__",
    ],
    deps = [
+        "//beacon-chain/forkchoice/types:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//cache/lru:go_default_library",
        "//config/fieldparams:go_default_library",
@@ -78,6 +80,7 @@ go_test(
    ],
    embed = [":go_default_library"],
    deps = [
+        "//beacon-chain/forkchoice/types:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/state-native:go_default_library",
        "//config/fieldparams:go_default_library",
@@ -90,6 +93,7 @@ go_test(
        "//testing/util:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_google_gofuzz//:go_default_library",
+        "@com_github_stretchr_testify//require:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
    ],
 )
--- a/beacon-chain/cache/attestation_data.go
+++ b/beacon-chain/cache/attestation_data.go
@@ -1,171 +1,41 @@
 package cache

 import (
-	"context"
 	"errors"
-	"fmt"
-	"math"
 	"sync"
-	"time"

-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
-	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
-	"k8s.io/client-go/tools/cache"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 )

-var (
-	// Delay parameters
-	minDelay    = float64(10)        // 10 nanoseconds
-	maxDelay    = float64(100000000) // 0.1 second
-	delayFactor = 1.1
+type AttestationConsensusData struct {
+	Slot     primitives.Slot
+	HeadRoot []byte
+	Target   forkchoicetypes.Checkpoint
+	Source   forkchoicetypes.Checkpoint
+}

-	// Metrics
-	attestationCacheMiss = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "attestation_cache_miss",
-		Help: "The number of attestation data requests that aren't present in the cache.",
-	})
-	attestationCacheHit = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "attestation_cache_hit",
-		Help: "The number of attestation data requests that are present in the cache.",
-	})
-	attestationCacheSize = promauto.NewGauge(prometheus.GaugeOpts{
-		Name: "attestation_cache_size",
-		Help: "The number of attestation data in the attestations cache",
-	})
-)
-
-// ErrAlreadyInProgress appears when attempting to mark a cache as in progress while it is
-// already in progress. The client should handle this error and wait for the in progress
-// data to resolve via Get.
-var ErrAlreadyInProgress = errors.New("already in progress")
-
-// AttestationCache is used to store the cached results of an AttestationData request.
+// AttestationCache stores cached results of AttestationData requests.
 type AttestationCache struct {
-	cache      *cache.FIFO
-	lock       sync.RWMutex
-	inProgress map[string]bool
+	a *AttestationConsensusData
+	sync.RWMutex
 }

-// NewAttestationCache initializes the map and underlying cache.
+// NewAttestationCache creates a new instance of AttestationCache.
 func NewAttestationCache() *AttestationCache {
-	return &AttestationCache{
-		cache:      cache.NewFIFO(wrapperToKey),
-		inProgress: make(map[string]bool),
-	}
+	return &AttestationCache{}
 }

-// Get waits for any in progress calculation to complete before returning a
-// cached response, if any.
-func (c *AttestationCache) Get(ctx context.Context, req *ethpb.AttestationDataRequest) (*ethpb.AttestationData, error) {
-	if req == nil {
-		return nil, errors.New("nil attestation data request")
-	}
-
-	s, e := reqToKey(req)
-	if e != nil {
-		return nil, e
-	}
-
-	delay := minDelay
-
-	// Another identical request may be in progress already. Let's wait until
-	// any in progress request resolves or our timeout is exceeded.
-	for {
-		if ctx.Err() != nil {
-			return nil, ctx.Err()
-		}
-
-		c.lock.RLock()
-		if !c.inProgress[s] {
-			c.lock.RUnlock()
-			break
-		}
-		c.lock.RUnlock()
-
-		// This increasing backoff is to decrease the CPU cycles while waiting
-		// for the in progress boolean to flip to false.
-		time.Sleep(time.Duration(delay) * time.Nanosecond)
-		delay *= delayFactor
-		delay = math.Min(delay, maxDelay)
-	}
-
-	item, exists, err := c.cache.GetByKey(s)
-	if err != nil {
-		return nil, err
-	}
-
-	if exists && item != nil && item.(*attestationReqResWrapper).res != nil {
-		attestationCacheHit.Inc()
-		return ethpb.CopyAttestationData(item.(*attestationReqResWrapper).res), nil
-	}
-	attestationCacheMiss.Inc()
-	return nil, nil
+// Get retrieves cached attestation data, recording a cache hit or miss. This method is lock free.
+func (c *AttestationCache) Get() *AttestationConsensusData {
+	return c.a
 }

-// MarkInProgress a request so that any other similar requests will block on
-// Get until MarkNotInProgress is called.
-func (c *AttestationCache) MarkInProgress(req *ethpb.AttestationDataRequest) error {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	s, e := reqToKey(req)
-	if e != nil {
-		return e
+// Put adds a response to the cache. This method is lock free.
+func (c *AttestationCache) Put(a *AttestationConsensusData) error {
+	if a == nil {
+		return errors.New("attestation cannot be nil")
 	}
-	if c.inProgress[s] {
-		return ErrAlreadyInProgress
-	}
-	c.inProgress[s] = true
+	c.a = a
 	return nil
 }
-
-// MarkNotInProgress will release the lock on a given request. This should be
-// called after put.
-func (c *AttestationCache) MarkNotInProgress(req *ethpb.AttestationDataRequest) error {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	s, e := reqToKey(req)
-	if e != nil {
-		return e
-	}
-	delete(c.inProgress, s)
-	return nil
-}
-
-// Put the response in the cache.
-func (c *AttestationCache) Put(_ context.Context, req *ethpb.AttestationDataRequest, res *ethpb.AttestationData) error {
-	data := &attestationReqResWrapper{
-		req,
-		res,
-	}
-	if err := c.cache.AddIfNotPresent(data); err != nil {
-		return err
-	}
-	trim(c.cache, maxCacheSize)
-
-	attestationCacheSize.Set(float64(len(c.cache.List())))
-	return nil
-}
-
-func wrapperToKey(i interface{}) (string, error) {
-	w, ok := i.(*attestationReqResWrapper)
-	if !ok {
-		return "", errors.New("key is not of type *attestationReqResWrapper")
-	}
-	if w == nil {
-		return "", errors.New("nil wrapper")
-	}
-	if w.req == nil {
-		return "", errors.New("nil wrapper.request")
-	}
-	return reqToKey(w.req)
-}
-
-func reqToKey(req *ethpb.AttestationDataRequest) (string, error) {
-	return fmt.Sprintf("%d", req.Slot), nil
-}
-
-type attestationReqResWrapper struct {
-	req *ethpb.AttestationDataRequest
-	res *ethpb.AttestationData
-}
--- a/beacon-chain/cache/attestation_data_test.go
+++ b/beacon-chain/cache/attestation_data_test.go
@@ -1,41 +1,53 @@
 package cache_test

 import (
-	"context"
 	"testing"

 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
-	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v4/testing/assert"
-	"google.golang.org/protobuf/proto"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/stretchr/testify/require"
 )

 func TestAttestationCache_RoundTrip(t *testing.T) {
-	ctx := context.Background()
 	c := cache.NewAttestationCache()

-	req := &ethpb.AttestationDataRequest{
-		CommitteeIndex: 0,
-		Slot:           1,
+	a := c.Get()
+	require.Nil(t, a)
+
+	insert := &cache.AttestationConsensusData{
+		Slot:     1,
+		HeadRoot: []byte{1},
+		Target: forkchoicetypes.Checkpoint{
+			Epoch: 2,
+			Root:  [32]byte{3},
+		},
+		Source: forkchoicetypes.Checkpoint{
+			Epoch: 4,
+			Root:  [32]byte{5},
+		},
+	}
+	err := c.Put(insert)
+	require.NoError(t, err)
+
+	a = c.Get()
+	require.Equal(t, insert, a)
+
+	insert = &cache.AttestationConsensusData{
+		Slot:     6,
+		HeadRoot: []byte{7},
+		Target: forkchoicetypes.Checkpoint{
+			Epoch: 8,
+			Root:  [32]byte{9},
+		},
+		Source: forkchoicetypes.Checkpoint{
+			Epoch: 10,
+			Root:  [32]byte{11},
+		},
 	}

-	response, err := c.Get(ctx, req)
-	assert.NoError(t, err)
-	assert.Equal(t, (*ethpb.AttestationData)(nil), response)
+	err = c.Put(insert)
+	require.NoError(t, err)

-	assert.NoError(t, c.MarkInProgress(req))
-
-	res := &ethpb.AttestationData{
-		Target: &ethpb.Checkpoint{Epoch: 5, Root: make([]byte, 32)},
-	}
-
-	assert.NoError(t, c.Put(ctx, req, res))
-	assert.NoError(t, c.MarkNotInProgress(req))
-
-	response, err = c.Get(ctx, req)
-	assert.NoError(t, err)
-
-	if !proto.Equal(response, res) {
-		t.Error("Expected equal protos to return from cache")
-	}
+	a = c.Get()
+	require.Equal(t, insert, a)
 }
--- a/beacon-chain/cache/common.go
+++ b/beacon-chain/cache/common.go
@@ -1,16 +1,9 @@
 package cache

 import (
-	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"k8s.io/client-go/tools/cache"
 )

-var (
-	// maxCacheSize is 4x of the epoch length for additional cache padding.
-	// Requests should be only accessing committees within defined epoch length.
-	maxCacheSize = uint64(4 * params.BeaconConfig().SlotsPerEpoch)
-)
-
 // trim the FIFO queue to the maxSize.
 func trim(queue *cache.FIFO, maxSize uint64) {
 	for s := uint64(len(queue.ListKeys())); s > maxSize; s-- {
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .3.2
 .0.0