add missing bazel build file

lock wrapper for safer forkchoice sharing
2026-01-11 06:18:05 -05:00 · 2023-12-01 09:49:52 -06:00 · 2023-11-22 14:49:23 -06:00
840 changed files with 39816 additions and 33721 deletions
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-7.0.0
+6.3.2
--- a/.buildkite-bazelrc
+++ b/.buildkite-bazelrc
@@ -9,8 +9,8 @@
 #build:remote-cache --strategy=Genrule=standalone

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

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

--- a/.github/actions/gomodtidy/Dockerfile
+++ b/.github/actions/gomodtidy/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.21-alpine
+FROM golang:alpine

 COPY entrypoint.sh /entrypoint.sh

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

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

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

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

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

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

      - name: Check out code into the Go module directory
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -6,83 +6,21 @@ run:
    - proto
    - tools/analyzers
  timeout: 10m
-  go: '1.21.5'
+  go: '1.19'

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

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

 prefix = "github.com/prysmaticlabs/prysm"

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

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

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

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

 ### Getting Started

--- a/134
+++ b/134
@@ -96,22 +96,11 @@ http_archive(
 )

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

-load("@rules_distroless//distroless:dependencies.bzl", "rules_distroless_dependencies")
-
-rules_distroless_dependencies()
-
-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",
@@ -137,10 +126,10 @@ http_archive(
        # Expose internals of go_test for custom build transitions.
        "//third_party:io_bazel_rules_go_test.patch",
    ],
-    sha256 = "d6ab6b57e48c09523e93050f13698f708428cfd5e619252e369d377af6597707",
+    sha256 = "91585017debb61982f7054c9688857a2ad1fd823fc3f9cb05048b0025c47d023",
    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.43.0/rules_go-v0.43.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.43.0/rules_go-v0.43.0.zip",
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.42.0/rules_go-v0.42.0.zip",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.42.0/rules_go-v0.42.0.zip",
    ],
 )

@@ -159,16 +148,67 @@ git_repository(
    # gazelle args: -go_prefix github.com/gogo/protobuf -proto legacy
 )

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

 # A multi-arch base image
 oci_pull(
    name = "linux_debian11_multiarch_base",  # Debian bullseye
-    digest = "sha256:b82f113425c5b5c714151aaacd8039bc141821cdcd3c65202d42bdf9c43ae60b",  # 2023-12-12
+    digest = "sha256:9b8e0854865dcaf49470b4ec305df45957020fbcf17b71eeb50ffd3bc5bf885d",  # 2023-05-17
    image = "gcr.io/distroless/cc-debian11",
    platforms = [
        "linux/amd64",
-        "linux/arm64/v8",
+        "linux/arm64",
    ],
    reproducible = True,
 )
@@ -182,7 +222,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()

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

@@ -204,8 +244,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "516d551cfb3e50e4ac2f42db0992f4ceb573a7cb1616d727a725c8161485329f",
-    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/refs/tags/v5.3.0.tar.gz",
+    sha256 = "91434d5fd5e1c6eb7b0174fed2afe25e09bddf00e1e4c431db931b2cee4e7773",
+    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/b8413ca42dc92308019d0d4db52c87e9e125c4e9.tar.gz",
 )

 http_archive(
@@ -223,7 +263,7 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.4.0-beta.5"
+consensus_spec_version = "v1.4.0-beta.3"

 bls_test_version = "v0.1.1"

@@ -239,7 +279,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "9017ffff84d64a7c4c9e6ff9f421f9479f71d3b463b738f54e02158dbb4f50f0",
+    sha256 = "67ae5b8fc368853da23d4297e480a4b7f4722fb970d1c7e2b6a5b7faef9cb907",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

@@ -255,7 +295,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "f08711682553fe7c9362f1400ed8c56b2fa9576df08581fcad4c508ba8ad4788",
+    sha256 = "82474f29fff4abd09fb1e71bafa98827e2573cf0ad02cf119610961831dc3bb5",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

@@ -271,7 +311,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "7ea3189e3879f2ac62467cbf2945c00b6c94d30cdefb2d645c630b1018c50e10",
+    sha256 = "60e4b6eb6c341daab7ee5614a8e3f28567247c504c593b951bfe919622c8ef8f",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

@@ -286,7 +326,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "4119992a2efc79e5cb2bdc07ed08c0b1fa32332cbd0d88e6467f34938df97026",
+    sha256 = "fdab9756c93a250219ff6a10d5a9faee1e2e6878a14508410409e307362c6991",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -322,22 +362,6 @@ filegroup(
    url = "https://github.com/eth-clients/eth2-networks/archive/7b4897888cebef23801540236f73123e21774954.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(
    name = "holesky_testnet",
    build_file_content = """
@@ -356,10 +380,10 @@ filegroup(

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

@@ -393,6 +417,24 @@ load("@prysm//testing/endtoend:deps.bzl", "e2e_deps")

 e2e_deps()

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

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

 go_library(
    name = "go_default_library",
-    srcs = [
-        "constants.go",
-        "headers.go",
-    ],
+    srcs = ["headers.go"],
    importpath = "github.com/prysmaticlabs/prysm/v4/api",
    visibility = ["//visibility:public"],
 )
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -11,12 +11,11 @@ go_library(
    visibility = ["//visibility:public"],
    deps = [
        "//api/client:go_default_library",
-        "//api/server: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/rpc/prysm/beacon:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -16,11 +16,10 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/api/client"
-	"github.com/prysmaticlabs/prysm/v4/api/server"
+	"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"
-	apibeacon "github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/prysm/beacon"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v4/network/forks"
@@ -32,7 +31,7 @@ const (
 	getSignedBlockPath       = "/eth/v2/beacon/blocks"
 	getBlockRootPath         = "/eth/v1/beacon/blocks/{{.Id}}/root"
 	getForkForStatePath      = "/eth/v1/beacon/states/{{.Id}}/fork"
-	getWeakSubjectivityPath  = "/prysm/v1/beacon/weak_subjectivity"
+	getWeakSubjectivityPath  = "/eth/v1/beacon/weak_subjectivity"
 	getForkSchedulePath      = "/eth/v1/config/fork_schedule"
 	getConfigSpecPath        = "/eth/v1/config/spec"
 	getStatePath             = "/eth/v2/debug/beacon/states"
@@ -259,16 +258,16 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 	if err != nil {
 		return nil, err
 	}
-	v := &apibeacon.GetWeakSubjectivityResponse{}
+	v := &apimiddleware.WeakSubjectivityResponse{}
 	err = json.Unmarshal(body, v)
 	if err != nil {
 		return nil, err
 	}
-	epoch, err := strconv.ParseUint(v.Data.WsCheckpoint.Epoch, 10, 64)
+	epoch, err := strconv.ParseUint(v.Data.Checkpoint.Epoch, 10, 64)
 	if err != nil {
 		return nil, err
 	}
-	blockRoot, err := hexutil.Decode(v.Data.WsCheckpoint.Root)
+	blockRoot, err := hexutil.Decode(v.Data.Checkpoint.Root)
 	if err != nil {
 		return nil, err
 	}
@@ -306,7 +305,7 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*shar
 	if resp.StatusCode != http.StatusOK {
 		decoder := json.NewDecoder(resp.Body)
 		decoder.DisallowUnknownFields()
-		errorJson := &server.IndexedVerificationFailureError{}
+		errorJson := &apimiddleware.IndexedVerificationFailureErrorJson{}
 		if err := decoder.Decode(errorJson); err != nil {
 			return errors.Wrapf(err, "failed to decode error JSON for %s", resp.Request.URL)
 		}
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -20,6 +20,8 @@ go_library(
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//monitoring/tracing:go_default_library",
+        "//network:go_default_library",
+        "//network/authorization:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
--- a/api/client/builder/bid.go
+++ b/api/client/builder/bid.go
@@ -6,6 +6,7 @@ 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"
 )
@@ -21,7 +22,7 @@ type SignedBid interface {
 // Bid is an interface describing the method set of a builder bid.
 type Bid interface {
 	Header() (interfaces.ExecutionData, error)
-	BlobKzgCommitments() ([][]byte, error)
+	BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error)
 	Value() []byte
 	Pubkey() []byte
 	Version() int
@@ -114,9 +115,9 @@ func (b builderBid) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeader(b.p.Header)
 }

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

 // Version --
@@ -168,9 +169,9 @@ func (b builderBidCapella) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeaderCapella(b.p.Header, blocks.PayloadValueToGwei(b.p.Value))
 }

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

 // Version --
@@ -252,9 +253,9 @@ func (b builderBidDeneb) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeaderDeneb(b.p.Header, blocks.PayloadValueToGwei(b.p.Value))
 }

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

 type signedBuilderBidDeneb struct {
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -19,6 +19,8 @@ import (
 	"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"
@@ -87,7 +89,7 @@ type BuilderClient interface {
 	NodeURL() string
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error)
 	Status(ctx context.Context) error
 }

@@ -102,7 +104,8 @@ type Client struct {
 // `host` is the base host + port used to construct request urls. This value can be
 // a URL string, or NewClient will assume an http endpoint if just `host:port` is used.
 func NewClient(host string, opts ...ClientOpt) (*Client, error) {
-	u, err := urlForHost(host)
+	endpoint := covertEndPoint(host)
+	u, err := urlForHost(endpoint.Url)
 	if err != nil {
 		return nil, err
 	}
@@ -118,7 +121,8 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {

 func urlForHost(h string) (*url.URL, error) {
 	// try to parse as url (being permissive)
-	if u, err := url.Parse(h); err == nil && u.Host != "" {
+	u, err := url.Parse(h)
+	if err == nil && u.Host != "" {
 		return u, nil
 	}
 	// try to parse as host:port
@@ -136,7 +140,7 @@ func (c *Client) NodeURL() string {

 type reqOption func(*http.Request)

-// do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder.
+// do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder/types.go.
 func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, err error) {
 	ctx, span := trace.StartSpan(ctx, "builder.client.do")
 	defer func() {
@@ -268,7 +272,11 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 	}
 	vs := make([]*shared.SignedValidatorRegistration, len(svr))
 	for i := 0; i < len(svr); i++ {
-		vs[i] = shared.SignedValidatorRegistrationFromConsensus(svr[i])
+		svrJson, err := shared.SignedValidatorRegistrationFromConsensus(svr[i])
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("failed to encode to SignedValidatorRegistration at index %d", i))
+		}
+		vs[i] = svrJson
 	}
 	body, err := json.Marshal(vs)
 	if err != nil {
@@ -283,7 +291,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid

 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
-func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	if !sb.IsBlinded() {
 		return nil, nil, errNotBlinded
 	}
@@ -367,9 +375,9 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := shared.SignedBlindedBeaconBlockDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockDeneb{Message: psb.Message, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockContentsDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockAndBlobsDeneb{SignedBlindedBlock: psb, SignedBlindedBlobSidecars: blobs})
 		if err != nil {
-			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockDeneb to json marshalable type")
+			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockContentsDeneb to json marshalable type")
 		}
 		body, err := json.Marshal(b)
 		if err != nil {
@@ -423,29 +431,38 @@ func non200Err(response *http.Response) error {
 	}
 	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
-	case http.StatusNoContent:
+	case 204:
 		log.WithError(ErrNoContent).Debug(msg)
 		return ErrNoContent
-	case http.StatusBadRequest:
+	case 400:
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		log.WithError(ErrBadRequest).Debug(msg)
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
 		return errors.Wrap(ErrBadRequest, errMessage.Message)
-	case http.StatusNotFound:
+	case 404:
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		log.WithError(ErrNotFound).Debug(msg)
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
 		return errors.Wrap(ErrNotFound, errMessage.Message)
-	case http.StatusInternalServerError:
-		log.WithError(ErrNotOK).Debug(msg)
+	case 500:
 		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
 			return errors.Wrap(jsonErr, "unable to read response body")
 		}
+		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, errMessage.Message)
 	default:
 		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, fmt.Sprintf("unsupported error code: %d", response.StatusCode))
 	}
 }
+
+func covertEndPoint(ep string) network.Endpoint {
+	return network.Endpoint{
+		Url: ep,
+		Auth: network.AuthorizationData{ // Auth is not used for builder.
+			Method: authorization.None,
+			Value:  "",
+		}}
+}
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -12,8 +12,10 @@ 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/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	types "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
@@ -268,20 +270,28 @@ func TestClient_GetHeader(t *testing.T) {
 		bidValue := bytesutil.ReverseByteOrder(bid.Value())
 		require.DeepEqual(t, bidValue, value.Bytes())
 		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
-		kcgCommitments, err := bid.BlobKzgCommitments()
+		bundle, err := bid.BlindedBlobsBundle()
 		require.NoError(t, err)
-		require.Equal(t, len(kcgCommitments) > 0, true)
-		for i := range kcgCommitments {
-			require.Equal(t, len(kcgCommitments[i]) == 48, true)
+		require.Equal(t, len(bundle.BlobRoots) <= fieldparams.MaxBlobsPerBlock && len(bundle.BlobRoots) > 0, true)
+		for i := range bundle.BlobRoots {
+			require.Equal(t, len(bundle.BlobRoots[i]) == fieldparams.RootLength, true)
+		}
+		require.Equal(t, len(bundle.KzgCommitments) > 0, true)
+		for i := range bundle.KzgCommitments {
+			require.Equal(t, len(bundle.KzgCommitments[i]) == 48, true)
+		}
+		require.Equal(t, len(bundle.Proofs) > 0, true)
+		for i := range bundle.Proofs {
+			require.Equal(t, len(bundle.Proofs[i]) == 48, true)
 		}
 	})
-	t.Run("deneb, too many kzg commitments", func(t *testing.T) {
+	t.Run("deneb, no bundle", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, expectedPath, r.URL.Path)
 				return &http.Response{
 					StatusCode: http.StatusOK,
-					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebTooManyBlobs)),
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebNoBundle)),
 					Request:    r.Clone(ctx),
 				}, nil
 			}),
@@ -290,9 +300,27 @@ func TestClient_GetHeader(t *testing.T) {
 			hc:      hc,
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}
-		_, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
-		require.ErrorContains(t, "could not extract proto message from header: too many blob commitments: 7", err)
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+		value, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
+		require.NoError(t, err)
+		require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", bid.Value()))
+		bidValue := bytesutil.ReverseByteOrder(bid.Value())
+		require.DeepEqual(t, bidValue, value.Bytes())
+		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
+		bundle, err := bid.BlindedBlobsBundle()
+		require.NoError(t, err)
+		require.Equal(t, (*v1.BlindedBlobsBundle)(nil), bundle)
 	})
+
 	t.Run("unsupported version", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -334,7 +362,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb, nil)
 		require.NoError(t, err)
 		require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash()))
 		bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
@@ -360,7 +388,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockCapella(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbb, nil)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -371,17 +399,18 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
 	t.Run("deneb", func(t *testing.T) {
-		test := testSignedBlindedBeaconBlockDeneb(t)
+
+		test := testSignedBlindedBeaconBlockAndBlobsDeneb(t)
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
 				require.Equal(t, "deneb", r.Header.Get("Eth-Consensus-Version"))
-				var req shared.SignedBlindedBeaconBlockDeneb
+				var req shared.SignedBlindedBeaconBlockContentsDeneb
 				err := json.NewDecoder(r.Body).Decode(&req)
 				require.NoError(t, err)
-				block, err := req.ToConsensus()
+				block, err := req.SignedBlindedBlock.ToConsensus()
 				require.NoError(t, err)
-				require.DeepEqual(t, block, test)
+				require.DeepEqual(t, block, test.SignedBlindedBlock)
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadDeneb)),
@@ -394,10 +423,10 @@ func TestSubmitBlindedBlock(t *testing.T) {
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}

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

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

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

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

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

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

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

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

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

-// FromBundleProto converts the proto bundle type to the builder
-// type.
-func FromBundleProto(bundle *v1.BlobsBundle) *BlobsBundle {
-	commitments := make([]hexutil.Bytes, len(bundle.KzgCommitments))
-	for i := range bundle.KzgCommitments {
-		commitments[i] = bytesutil.SafeCopyBytes(bundle.KzgCommitments[i])
-	}
-	proofs := make([]hexutil.Bytes, len(bundle.Proofs))
-	for i := range bundle.Proofs {
-		proofs[i] = bytesutil.SafeCopyBytes(bundle.Proofs[i])
-	}
-	blobs := make([]hexutil.Bytes, len(bundle.Blobs))
-	for i := range bundle.Blobs {
-		blobs[i] = bytesutil.SafeCopyBytes(bundle.Blobs[i])
-	}
-	return &BlobsBundle{
-		Commitments: commitments,
-		Proofs:      proofs,
-		Blobs:       blobs,
-	}
-}
-
 // ToProto returns ExecutionPayloadDeneb Proto and BlobsBundle Proto separately.
 func (r *ExecPayloadResponseDeneb) ToProto() (*v1.ExecutionPayloadDeneb, *v1.BlobsBundle, error) {
 	if r.Data == nil {
--- a/api/client/builder/types_test.go
+++ b/api/client/builder/types_test.go
@@ -38,7 +38,8 @@ func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
 		},
 		Signature: make([]byte, 96),
 	}
-	a := shared.SignedValidatorRegistrationFromConsensus(svr)
+	a, err := shared.SignedValidatorRegistrationFromConsensus(svr)
+	require.NoError(t, err)
 	je, err := json.Marshal(a)
 	require.NoError(t, err)
 	// decode with a struct w/ plain strings so we can check the string encoding of the hex fields
@@ -141,9 +142,17 @@ var testExampleHeaderResponseDeneb = `{
 		"blob_gas_used": "1",	
 		"excess_blob_gas": "2"	
      },
-      "blob_kzg_commitments": [
+      "blinded_blobs_bundle": {
+        "commitments": [
          "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
-	  ],
+        ],
+        "proofs": [
+          "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
+        ],
+        "blob_roots": [
+          "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"
+        ]
+      },
      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
    },
@@ -209,39 +218,6 @@ var testExampleHeaderResponseUnknownVersion = `{
  }
 }`

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

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

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

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

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

 func pbEth1Data() *eth.Eth1Data {
--- a/api/client/errors.go
+++ b/api/client/errors.go
@@ -32,7 +32,7 @@ func Non200Err(response *http.Response) error {
 	}
 	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
-	case http.StatusNotFound:
+	case 404:
 		return errors.Wrap(ErrNotFound, msg)
 	default:
 		return errors.Wrap(ErrNotOK, msg)
--- a/api/constants.go
+++ b/api/constants.go
@@ -1,3 +0,0 @@
-package api
-
-const WebUrlPrefix = "/v2/validator/"
--- a/api/gateway/BUILD.bazel
+++ b/api/gateway/BUILD.bazel
@@ -14,11 +14,12 @@ go_library(
        "//validator:__subpackages__",
    ],
    deps = [
-        "//api/server:go_default_library",
+        "//api/gateway/apimiddleware:go_default_library",
        "//runtime:go_default_library",
        "@com_github_gorilla_mux//:go_default_library",
        "@com_github_grpc_ecosystem_grpc_gateway_v2//runtime:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_rs_cors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@org_golang_google_grpc//:go_default_library",
        "@org_golang_google_grpc//connectivity:go_default_library",
@@ -33,6 +34,7 @@ go_test(
    srcs = ["gateway_test.go"],
    embed = [":go_default_library"],
    deps = [
+        "//api/gateway/apimiddleware:go_default_library",
        "//cmd/beacon-chain/flags:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
--- a/api/gateway/apimiddleware/BUILD.bazel
+++ b/api/gateway/apimiddleware/BUILD.bazel
@@ -0,0 +1,43 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "api_middleware.go",
+        "log.go",
+        "param_handling.go",
+        "process_field.go",
+        "process_request.go",
+        "structs.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//api:go_default_library",
+        "//api/grpc:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_gorilla_mux//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@com_github_wealdtech_go_bytesutil//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "param_handling_test.go",
+        "process_request_test.go",
+    ],
+    embed = [":go_default_library"],
+    deps = [
+        "//api:go_default_library",
+        "//api/grpc:go_default_library",
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "@com_github_gorilla_mux//:go_default_library",
+        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
+    ],
+)
--- a/api/gateway/apimiddleware/api_middleware.go
+++ b/api/gateway/apimiddleware/api_middleware.go
@@ -0,0 +1,265 @@
+package apimiddleware
+
+import (
+	"net/http"
+	"reflect"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+// ApiProxyMiddleware is a proxy between an Ethereum consensus API HTTP client and grpc-gateway.
+// The purpose of the proxy is to handle HTTP requests and gRPC responses in such a way that:
+//   - Ethereum consensus API requests can be handled by grpc-gateway correctly
+//   - gRPC responses can be returned as spec-compliant Ethereum consensus API responses
+type ApiProxyMiddleware struct {
+	GatewayAddress  string
+	EndpointCreator EndpointFactory
+	Timeout         time.Duration
+	router          *mux.Router
+}
+
+// EndpointFactory is responsible for creating new instances of Endpoint values.
+type EndpointFactory interface {
+	Create(path string) (*Endpoint, error)
+	Paths() []string
+	IsNil() bool
+}
+
+// Endpoint is a representation of an API HTTP endpoint that should be proxied by the middleware.
+type Endpoint struct {
+	Path               string          // The path of the HTTP endpoint.
+	GetResponse        interface{}     // The struct corresponding to the JSON structure used in a GET response.
+	PostRequest        interface{}     // The struct corresponding to the JSON structure used in a POST request.
+	PostResponse       interface{}     // The struct corresponding to the JSON structure used in a POST response.
+	DeleteRequest      interface{}     // The struct corresponding to the JSON structure used in a DELETE request.
+	DeleteResponse     interface{}     // The struct corresponding to the JSON structure used in a DELETE response.
+	RequestURLLiterals []string        // Names of URL parameters that should not be base64-encoded.
+	RequestQueryParams []QueryParam    // Query parameters of the request.
+	Err                ErrorJson       // The struct corresponding to the error that should be returned in case of a request failure.
+	Hooks              HookCollection  // A collection of functions that can be invoked at various stages of the request/response cycle.
+	CustomHandlers     []CustomHandler // Functions that will be executed instead of the default request/response behaviour.
+}
+
+// RunDefault expresses whether the default processing logic should be carried out after running a pre hook.
+type RunDefault bool
+
+// DefaultEndpoint returns an Endpoint with default configuration, e.g. DefaultErrorJson for error handling.
+func DefaultEndpoint() Endpoint {
+	return Endpoint{
+		Err: &DefaultErrorJson{},
+	}
+}
+
+// QueryParam represents a single query parameter's metadata.
+type QueryParam struct {
+	Name string
+	Hex  bool
+	Enum bool
+}
+
+// CustomHandler is a function that can be invoked at the very beginning of the request,
+// essentially replacing the whole default request/response logic with custom logic for a specific endpoint.
+type CustomHandler = func(m *ApiProxyMiddleware, endpoint Endpoint, w http.ResponseWriter, req *http.Request) (handled bool)
+
+// HookCollection contains hooks that can be used to amend the default request/response cycle with custom logic for a specific endpoint.
+type HookCollection struct {
+	OnPreDeserializeRequestBodyIntoContainer      func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) (RunDefault, ErrorJson)
+	OnPostDeserializeRequestBodyIntoContainer     func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson
+	OnPreDeserializeGrpcResponseBodyIntoContainer func([]byte, interface{}) (RunDefault, ErrorJson)
+	OnPreSerializeMiddlewareResponseIntoJson      func(interface{}) (RunDefault, []byte, ErrorJson)
+}
+
+// fieldProcessor applies the processing function f to a value when the tag is present on the field.
+type fieldProcessor struct {
+	tag string
+	f   func(value reflect.Value) error
+}
+
+// Run starts the proxy, registering all proxy endpoints.
+func (m *ApiProxyMiddleware) Run(gatewayRouter *mux.Router) {
+	for _, path := range m.EndpointCreator.Paths() {
+		gatewayRouter.HandleFunc(path, m.WithMiddleware(path))
+	}
+	m.router = gatewayRouter
+}
+
+// ServeHTTP for the proxy middleware.
+func (m *ApiProxyMiddleware) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	m.router.ServeHTTP(w, req)
+}
+
+// WithMiddleware wraps the given endpoint handler with the middleware logic.
+func (m *ApiProxyMiddleware) WithMiddleware(path string) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		endpoint, err := m.EndpointCreator.Create(path)
+		if err != nil {
+			log.WithError(err).Errorf("Could not create endpoint for path: %s", path)
+			return
+		}
+
+		for _, handler := range endpoint.CustomHandlers {
+			if handler(m, *endpoint, w, req) {
+				return
+			}
+		}
+
+		if req.Method == "POST" {
+			if errJson := handlePostRequestForEndpoint(endpoint, w, req); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+		}
+
+		if req.Method == "DELETE" && req.Body != http.NoBody {
+			if errJson := handleDeleteRequestForEndpoint(endpoint, req); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+		}
+
+		if errJson := m.PrepareRequestForProxying(*endpoint, req); errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+		grpcResp, errJson := m.ProxyRequest(req)
+		if errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+		grpcRespBody, errJson := ReadGrpcResponseBody(grpcResp.Body)
+		if errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+
+		var respJson []byte
+		if !GrpcResponseIsEmpty(grpcRespBody) {
+			respHasError, errJson := HandleGrpcResponseError(endpoint.Err, grpcResp, grpcRespBody, w)
+			if errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+			if respHasError {
+				return
+			}
+
+			var resp interface{}
+			if req.Method == "GET" {
+				resp = endpoint.GetResponse
+			} else if req.Method == "DELETE" {
+				resp = endpoint.DeleteResponse
+			} else {
+				resp = endpoint.PostResponse
+			}
+			if errJson := deserializeGrpcResponseBodyIntoContainerWrapped(endpoint, grpcRespBody, resp); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+			if errJson := ProcessMiddlewareResponseFields(resp); errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+
+			respJson, errJson = serializeMiddlewareResponseIntoJsonWrapped(endpoint, respJson, resp)
+			if errJson != nil {
+				WriteError(w, errJson, nil)
+				return
+			}
+		}
+
+		if errJson := WriteMiddlewareResponseHeadersAndBody(grpcResp, respJson, w); errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+		if errJson := Cleanup(grpcResp.Body); errJson != nil {
+			WriteError(w, errJson, nil)
+			return
+		}
+	}
+}
+
+func handlePostRequestForEndpoint(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson {
+	if errJson := deserializeRequestBodyIntoContainerWrapped(endpoint, req, w); errJson != nil {
+		return errJson
+	}
+	if errJson := ProcessRequestContainerFields(endpoint.PostRequest); errJson != nil {
+		return errJson
+	}
+	return SetRequestBodyToRequestContainer(endpoint.PostRequest, req)
+}
+
+func handleDeleteRequestForEndpoint(endpoint *Endpoint, req *http.Request) ErrorJson {
+	if errJson := DeserializeRequestBodyIntoContainer(req.Body, endpoint.DeleteRequest); errJson != nil {
+		return errJson
+	}
+	if errJson := ProcessRequestContainerFields(endpoint.DeleteRequest); errJson != nil {
+		return errJson
+	}
+	return SetRequestBodyToRequestContainer(endpoint.DeleteRequest, req)
+}
+
+func deserializeRequestBodyIntoContainerWrapped(endpoint *Endpoint, req *http.Request, w http.ResponseWriter) ErrorJson {
+	runDefault := true
+	if endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer != nil {
+		run, errJson := endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer(endpoint, w, req)
+		if errJson != nil {
+			return errJson
+		}
+		if !run {
+			runDefault = false
+		}
+	}
+	if runDefault {
+		if errJson := DeserializeRequestBodyIntoContainer(req.Body, endpoint.PostRequest); errJson != nil {
+			return errJson
+		}
+	}
+	if endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer != nil {
+		if errJson := endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer(endpoint, w, req); errJson != nil {
+			return errJson
+		}
+	}
+	return nil
+}
+
+func deserializeGrpcResponseBodyIntoContainerWrapped(endpoint *Endpoint, grpcResponseBody []byte, resp interface{}) ErrorJson {
+	runDefault := true
+	if endpoint.Hooks.OnPreDeserializeGrpcResponseBodyIntoContainer != nil {
+		run, errJson := endpoint.Hooks.OnPreDeserializeGrpcResponseBodyIntoContainer(grpcResponseBody, resp)
+		if errJson != nil {
+			return errJson
+		}
+		if !run {
+			runDefault = false
+		}
+	}
+	if runDefault {
+		if errJson := DeserializeGrpcResponseBodyIntoContainer(grpcResponseBody, resp); errJson != nil {
+			return errJson
+		}
+	}
+	return nil
+}
+
+func serializeMiddlewareResponseIntoJsonWrapped(endpoint *Endpoint, respJson []byte, resp interface{}) ([]byte, ErrorJson) {
+	runDefault := true
+	var errJson ErrorJson
+	if endpoint.Hooks.OnPreSerializeMiddlewareResponseIntoJson != nil {
+		var run RunDefault
+		run, respJson, errJson = endpoint.Hooks.OnPreSerializeMiddlewareResponseIntoJson(resp)
+		if errJson != nil {
+			return nil, errJson
+		}
+		if !run {
+			runDefault = false
+		}
+	}
+	if runDefault {
+		respJson, errJson = SerializeMiddlewareResponseIntoJson(resp)
+		if errJson != nil {
+			return nil, errJson
+		}
+	}
+	return respJson, nil
+}
--- a/api/gateway/apimiddleware/log.go
+++ b/api/gateway/apimiddleware/log.go
@@ -0,0 +1,5 @@
+package apimiddleware
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "apimiddleware")
--- a/api/gateway/apimiddleware/param_handling.go
+++ b/api/gateway/apimiddleware/param_handling.go
@@ -0,0 +1,103 @@
+package apimiddleware
+
+import (
+	"encoding/base64"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/gorilla/mux"
+	butil "github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/wealdtech/go-bytesutil"
+)
+
+// HandleURLParameters processes URL parameters, allowing parameterized URLs to be safely and correctly proxied to grpc-gateway.
+func HandleURLParameters(url string, req *http.Request, literals []string) ErrorJson {
+	segments := strings.Split(url, "/")
+
+segmentsLoop:
+	for i, s := range segments {
+		// We only care about segments which are parameterized.
+		if isRequestParam(s) {
+			// Don't do anything with parameters which should be forwarded literally to gRPC.
+			for _, l := range literals {
+				if s == "{"+l+"}" {
+					continue segmentsLoop
+				}
+			}
+
+			routeVar := mux.Vars(req)[s[1:len(s)-1]]
+			bRouteVar := []byte(routeVar)
+			if butil.IsHex(bRouteVar) {
+				var err error
+				bRouteVar, err = bytesutil.FromHexString(string(bRouteVar))
+				if err != nil {
+					return InternalServerErrorWithMessage(err, "could not process URL parameter")
+				}
+			}
+			// Converting hex to base64 may result in a value which malforms the URL.
+			// We use URLEncoding to safely escape such values.
+			base64RouteVar := base64.URLEncoding.EncodeToString(bRouteVar)
+
+			// Merge segments back into the full URL.
+			splitPath := strings.Split(req.URL.Path, "/")
+			splitPath[i] = base64RouteVar
+			req.URL.Path = strings.Join(splitPath, "/")
+		}
+	}
+	return nil
+}
+
+// HandleQueryParameters processes query parameters, allowing them to be safely and correctly proxied to grpc-gateway.
+func HandleQueryParameters(req *http.Request, params []QueryParam) ErrorJson {
+	queryParams := req.URL.Query()
+
+	normalizeQueryValues(queryParams)
+
+	for key, vals := range queryParams {
+		for _, p := range params {
+			if key == p.Name {
+				if p.Hex {
+					queryParams.Del(key)
+					for _, v := range vals {
+						b := []byte(v)
+						if butil.IsHex(b) {
+							var err error
+							b, err = bytesutil.FromHexString(v)
+							if err != nil {
+								return InternalServerErrorWithMessage(err, "could not process query parameter")
+							}
+						}
+						queryParams.Add(key, base64.URLEncoding.EncodeToString(b))
+					}
+				}
+				if p.Enum {
+					queryParams.Del(key)
+					for _, v := range vals {
+						// gRPC expects uppercase enum values.
+						queryParams.Add(key, strings.ToUpper(v))
+					}
+				}
+			}
+		}
+	}
+	req.URL.RawQuery = queryParams.Encode()
+	return nil
+}
+
+// isRequestParam verifies whether the passed string is a request parameter.
+// Request parameters are enclosed in { and }.
+func isRequestParam(s string) bool {
+	return len(s) > 2 && s[0] == '{' && s[len(s)-1] == '}'
+}
+
+func normalizeQueryValues(queryParams url.Values) {
+	// Replace comma-separated values with individual values.
+	for key, vals := range queryParams {
+		splitVals := make([]string, 0)
+		for _, v := range vals {
+			splitVals = append(splitVals, strings.Split(v, ",")...)
+		}
+		queryParams[key] = splitVals
+	}
+}
--- a/api/gateway/apimiddleware/param_handling_test.go
+++ b/api/gateway/apimiddleware/param_handling_test.go
@@ -0,0 +1,124 @@
+package apimiddleware
+
+import (
+	"bytes"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gorilla/mux"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func TestHandleURLParameters(t *testing.T) {
+	var body bytes.Buffer
+
+	t.Run("no_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example/bar", &body)
+
+		errJson := HandleURLParameters("/not_param", request, []string{})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/bar", request.URL.Path)
+	})
+
+	t.Run("with_params", func(t *testing.T) {
+		muxVars := make(map[string]string)
+		muxVars["bar_param"] = "bar"
+		muxVars["quux_param"] = "quux"
+		request := httptest.NewRequest("GET", "http://foo.example/bar/baz/quux", &body)
+		request = mux.SetURLVars(request, muxVars)
+
+		errJson := HandleURLParameters("/{bar_param}/not_param/{quux_param}", request, []string{})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/YmFy/baz/cXV1eA==", request.URL.Path)
+	})
+
+	t.Run("with_literal", func(t *testing.T) {
+		muxVars := make(map[string]string)
+		muxVars["bar_param"] = "bar"
+		request := httptest.NewRequest("GET", "http://foo.example/bar/baz", &body)
+		request = mux.SetURLVars(request, muxVars)
+
+		errJson := HandleURLParameters("/{bar_param}/not_param/", request, []string{"bar_param"})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/bar/baz", request.URL.Path)
+	})
+
+	t.Run("with_hex", func(t *testing.T) {
+		muxVars := make(map[string]string)
+		muxVars["hex_param"] = "0x626172"
+		request := httptest.NewRequest("GET", "http://foo.example/0x626172/baz", &body)
+		request = mux.SetURLVars(request, muxVars)
+
+		errJson := HandleURLParameters("/{hex_param}/not_param/", request, []string{})
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "/YmFy/baz", request.URL.Path)
+	})
+}
+
+func TestHandleQueryParameters(t *testing.T) {
+	var body bytes.Buffer
+
+	t.Run("regular_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example?bar=bar&baz=baz", &body)
+
+		errJson := HandleQueryParameters(request, []QueryParam{{Name: "bar"}, {Name: "baz"}})
+		require.Equal(t, true, errJson == nil)
+		query := request.URL.Query()
+		v, ok := query["bar"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "bar", v[0])
+		v, ok = query["baz"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "baz", v[0])
+	})
+
+	t.Run("hex_and_enum_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example?hex=0x626172&baz=baz", &body)
+
+		errJson := HandleQueryParameters(request, []QueryParam{{Name: "hex", Hex: true}, {Name: "baz", Enum: true}})
+		require.Equal(t, true, errJson == nil)
+		query := request.URL.Query()
+		v, ok := query["hex"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "YmFy", v[0])
+		v, ok = query["baz"]
+		require.Equal(t, true, ok, "query param not found")
+		require.Equal(t, 1, len(v), "wrong number of query param values")
+		assert.Equal(t, "BAZ", v[0])
+	})
+}
+
+func TestIsRequestParam(t *testing.T) {
+	tests := []struct {
+		s string
+		b bool
+	}{
+		{"", false},
+		{"{", false},
+		{"}", false},
+		{"{}", false},
+		{"{x}", true},
+		{"{very_long_parameter_name_with_underscores}", true},
+	}
+	for _, tt := range tests {
+		b := isRequestParam(tt.s)
+		assert.Equal(t, tt.b, b)
+	}
+}
+
+func TestNormalizeQueryValues(t *testing.T) {
+	input := make(map[string][]string)
+	input["key"] = []string{"value1", "value2,value3,value4", "value5"}
+
+	normalizeQueryValues(input)
+	require.Equal(t, 5, len(input["key"]))
+	assert.Equal(t, "value1", input["key"][0])
+	assert.Equal(t, "value2", input["key"][1])
+	assert.Equal(t, "value3", input["key"][2])
+	assert.Equal(t, "value4", input["key"][3])
+	assert.Equal(t, "value5", input["key"][4])
+}
--- a/api/gateway/apimiddleware/process_field.go
+++ b/api/gateway/apimiddleware/process_field.go
@@ -0,0 +1,179 @@
+package apimiddleware
+
+import (
+	"encoding/base64"
+	"fmt"
+	"math/big"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
+	"github.com/wealdtech/go-bytesutil"
+)
+
+// processField calls each processor function on any field that has the matching tag set.
+// It is a recursive function.
+func processField(s interface{}, processors []fieldProcessor) error {
+	kind := reflect.TypeOf(s).Kind()
+	if kind != reflect.Ptr && kind != reflect.Slice && kind != reflect.Array {
+		return fmt.Errorf("processing fields of kind '%v' is unsupported", kind)
+	}
+
+	t := reflect.TypeOf(s).Elem()
+	v := reflect.Indirect(reflect.ValueOf(s))
+
+	for i := 0; i < t.NumField(); i++ {
+		switch v.Field(i).Kind() {
+		case reflect.Slice:
+			sliceElem := t.Field(i).Type.Elem()
+			kind := sliceElem.Kind()
+			// Recursively process slices to struct pointers.
+			switch {
+			case kind == reflect.Ptr && sliceElem.Elem().Kind() == reflect.Struct:
+				for j := 0; j < v.Field(i).Len(); j++ {
+					if err := processField(v.Field(i).Index(j).Interface(), processors); err != nil {
+						return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+					}
+				}
+			// Process each string in string slices.
+			case kind == reflect.String:
+				for _, proc := range processors {
+					_, hasTag := t.Field(i).Tag.Lookup(proc.tag)
+					if !hasTag {
+						continue
+					}
+					for j := 0; j < v.Field(i).Len(); j++ {
+						if err := proc.f(v.Field(i).Index(j)); err != nil {
+							return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+						}
+					}
+				}
+			}
+		// Recursively process struct pointers.
+		case reflect.Ptr:
+			if v.Field(i).Elem().Kind() == reflect.Struct {
+				if err := processField(v.Field(i).Interface(), processors); err != nil {
+					return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+				}
+			}
+		default:
+			field := t.Field(i)
+			for _, proc := range processors {
+				if _, hasTag := field.Tag.Lookup(proc.tag); hasTag {
+					if err := proc.f(v.Field(i)); err != nil {
+						return errors.Wrapf(err, "could not process field '%s'", t.Field(i).Name)
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func hexToBase64Processor(v reflect.Value) error {
+	if v.String() == "0x" {
+		v.SetString("")
+		return nil
+	}
+	b, err := bytesutil.FromHexString(v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(base64.StdEncoding.EncodeToString(b))
+	return nil
+}
+
+func base64ToHexProcessor(v reflect.Value) error {
+	if v.String() == "" {
+		// Empty hex values are represented as "0x".
+		v.SetString("0x")
+		return nil
+	}
+	b, err := base64.StdEncoding.DecodeString(v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(hexutil.Encode(b))
+	return nil
+}
+
+func base64ToChecksumAddressProcessor(v reflect.Value) error {
+	if v.String() == "" {
+		// Empty hex values are represented as "0x".
+		v.SetString("0x")
+		return nil
+	}
+	b, err := base64.StdEncoding.DecodeString(v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(common.BytesToAddress(b).Hex())
+	return nil
+}
+
+func base64ToUint256Processor(v reflect.Value) error {
+	if v.String() == "" {
+		return nil
+	}
+	littleEndian, err := base64.StdEncoding.DecodeString(v.String())
+	if err != nil {
+		return err
+	}
+	if len(littleEndian) != 32 {
+		return errors.New("invalid length for Uint256")
+	}
+
+	// Integers are stored as little-endian, but
+	// big.Int expects big-endian. So we need to reverse
+	// the byte order before decoding.
+	var bigEndian [32]byte
+	for i := 0; i < len(littleEndian); i++ {
+		bigEndian[i] = littleEndian[len(littleEndian)-1-i]
+	}
+	var uint256 big.Int
+	uint256.SetBytes(bigEndian[:])
+	v.SetString(uint256.String())
+	return nil
+}
+
+func uint256ToBase64Processor(v reflect.Value) error {
+	if v.String() == "" {
+		return nil
+	}
+	uint256, ok := new(big.Int).SetString(v.String(), 10)
+	if !ok {
+		return fmt.Errorf("could not parse Uint256")
+	}
+	bigEndian := uint256.Bytes()
+	if len(bigEndian) > 32 {
+		return fmt.Errorf("number too big for Uint256")
+	}
+
+	// Integers are stored as little-endian, but
+	// big.Int gives big-endian. So we need to reverse
+	// the byte order before encoding.
+	var littleEndian [32]byte
+	for i := 0; i < len(bigEndian); i++ {
+		littleEndian[i] = bigEndian[len(bigEndian)-1-i]
+	}
+	v.SetString(base64.StdEncoding.EncodeToString(littleEndian[:]))
+	return nil
+}
+
+func enumToLowercaseProcessor(v reflect.Value) error {
+	v.SetString(strings.ToLower(v.String()))
+	return nil
+}
+
+func timeToUnixProcessor(v reflect.Value) error {
+	t, err := time.Parse(time.RFC3339, v.String())
+	if err != nil {
+		return err
+	}
+	v.SetString(strconv.FormatUint(uint64(t.Unix()), 10))
+	return nil
+}
--- a/api/gateway/apimiddleware/process_request.go
+++ b/api/gateway/apimiddleware/process_request.go
@@ -0,0 +1,283 @@
+package apimiddleware
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/api"
+	"github.com/prysmaticlabs/prysm/v4/api/grpc"
+)
+
+// DeserializeRequestBodyIntoContainer deserializes the request's body into an endpoint-specific struct.
+func DeserializeRequestBodyIntoContainer(body io.Reader, requestContainer interface{}) ErrorJson {
+	decoder := json.NewDecoder(body)
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&requestContainer); err != nil {
+		if strings.Contains(err.Error(), "json: unknown field") {
+			e := errors.Wrap(err, "could not decode request body")
+			return &DefaultErrorJson{
+				Message: e.Error(),
+				Code:    http.StatusBadRequest,
+			}
+		}
+		return InternalServerErrorWithMessage(err, "could not decode request body")
+	}
+	return nil
+}
+
+// ProcessRequestContainerFields processes fields of an endpoint-specific container according to field tags.
+func ProcessRequestContainerFields(requestContainer interface{}) ErrorJson {
+	if err := processField(requestContainer, []fieldProcessor{
+		{
+			tag: "hex",
+			f:   hexToBase64Processor,
+		},
+		{
+			tag: "uint256",
+			f:   uint256ToBase64Processor,
+		},
+	}); err != nil {
+		return InternalServerErrorWithMessage(err, "could not process request data")
+	}
+	return nil
+}
+
+// SetRequestBodyToRequestContainer makes the endpoint-specific container the new body of the request.
+func SetRequestBodyToRequestContainer(requestContainer interface{}, req *http.Request) ErrorJson {
+	// Serialize the struct, which now includes a base64-encoded value, into JSON.
+	j, err := json.Marshal(requestContainer)
+	if err != nil {
+		return InternalServerErrorWithMessage(err, "could not marshal request")
+	}
+	// Set the body to the new JSON.
+	req.Body = io.NopCloser(bytes.NewReader(j))
+	req.Header.Set("Content-Length", strconv.Itoa(len(j)))
+	req.ContentLength = int64(len(j))
+	return nil
+}
+
+// PrepareRequestForProxying applies additional logic to the request so that it can be correctly proxied to grpc-gateway.
+func (m *ApiProxyMiddleware) PrepareRequestForProxying(endpoint Endpoint, req *http.Request) ErrorJson {
+	req.URL.Scheme = "http"
+	req.URL.Host = m.GatewayAddress
+	req.RequestURI = ""
+	if errJson := HandleURLParameters(endpoint.Path, req, endpoint.RequestURLLiterals); errJson != nil {
+		return errJson
+	}
+	if errJson := HandleQueryParameters(req, endpoint.RequestQueryParams); errJson != nil {
+		return errJson
+	}
+	// We have to add the prefix after handling parameters because adding the prefix changes URL segment indexing.
+	req.URL.Path = "/internal" + req.URL.Path
+	return nil
+}
+
+// ProxyRequest proxies the request to grpc-gateway.
+func (m *ApiProxyMiddleware) ProxyRequest(req *http.Request) (*http.Response, ErrorJson) {
+	// We do not use http.DefaultClient because it does not have any timeout.
+	netClient := &http.Client{Timeout: m.Timeout}
+	grpcResp, err := netClient.Do(req)
+	if err != nil {
+		if err, ok := err.(net.Error); ok && err.Timeout() {
+			return nil, TimeoutError()
+		}
+		return nil, InternalServerErrorWithMessage(err, "could not proxy request")
+	}
+	if grpcResp == nil {
+		return nil, &DefaultErrorJson{Message: "nil response from gRPC-gateway", Code: http.StatusInternalServerError}
+	}
+	return grpcResp, nil
+}
+
+// ReadGrpcResponseBody reads the body from the grpc-gateway's response.
+func ReadGrpcResponseBody(r io.Reader) ([]byte, ErrorJson) {
+	body, err := io.ReadAll(r)
+	if err != nil {
+		return nil, InternalServerErrorWithMessage(err, "could not read response body")
+	}
+	return body, nil
+}
+
+// HandleGrpcResponseError acts on an error that resulted from a grpc-gateway's response.
+// Whether there was an error is indicated by the bool return value. In case of an error,
+// there is no need to write to the response because it's taken care of by the function.
+func HandleGrpcResponseError(errJson ErrorJson, resp *http.Response, respBody []byte, w http.ResponseWriter) (bool, ErrorJson) {
+	responseHasError := false
+	if err := json.Unmarshal(respBody, errJson); err != nil {
+		return false, InternalServerErrorWithMessage(err, "could not unmarshal error")
+	}
+	if errJson.Msg() != "" {
+		responseHasError = true
+		// Something went wrong, but the request completed, meaning we can write headers and the error message.
+		for h, vs := range resp.Header {
+			for _, v := range vs {
+				if strings.HasSuffix(h, api.VersionHeader) {
+					w.Header().Set(api.VersionHeader, v)
+				} else {
+					w.Header().Set(h, v)
+				}
+			}
+		}
+		// Handle gRPC timeout.
+		if resp.StatusCode == http.StatusGatewayTimeout {
+			WriteError(w, TimeoutError(), resp.Header)
+		} else {
+			// Set code to HTTP code because unmarshalled body contained gRPC code.
+			errJson.SetCode(resp.StatusCode)
+			WriteError(w, errJson, resp.Header)
+		}
+	}
+	return responseHasError, nil
+}
+
+// GrpcResponseIsEmpty determines whether the grpc-gateway's response body contains no data.
+func GrpcResponseIsEmpty(grpcResponseBody []byte) bool {
+	return len(grpcResponseBody) == 0 || string(grpcResponseBody) == "{}"
+}
+
+// DeserializeGrpcResponseBodyIntoContainer deserializes the grpc-gateway's response body into an endpoint-specific struct.
+func DeserializeGrpcResponseBodyIntoContainer(body []byte, responseContainer interface{}) ErrorJson {
+	if err := json.Unmarshal(body, &responseContainer); err != nil {
+		return InternalServerErrorWithMessage(err, "could not unmarshal response")
+	}
+	return nil
+}
+
+// ProcessMiddlewareResponseFields processes fields of an endpoint-specific container according to field tags.
+func ProcessMiddlewareResponseFields(responseContainer interface{}) ErrorJson {
+	if err := processField(responseContainer, []fieldProcessor{
+		{
+			tag: "hex",
+			f:   base64ToHexProcessor,
+		},
+		{
+			tag: "address",
+			f:   base64ToChecksumAddressProcessor,
+		},
+		{
+			tag: "enum",
+			f:   enumToLowercaseProcessor,
+		},
+		{
+			tag: "time",
+			f:   timeToUnixProcessor,
+		},
+		{
+			tag: "uint256",
+			f:   base64ToUint256Processor,
+		},
+	}); err != nil {
+		return InternalServerErrorWithMessage(err, "could not process response data")
+	}
+	return nil
+}
+
+// SerializeMiddlewareResponseIntoJson serializes the endpoint-specific response struct into a JSON representation.
+func SerializeMiddlewareResponseIntoJson(responseContainer interface{}) (jsonResponse []byte, errJson ErrorJson) {
+	j, err := json.Marshal(responseContainer)
+	if err != nil {
+		return nil, InternalServerErrorWithMessage(err, "could not marshal response")
+	}
+	return j, nil
+}
+
+// WriteMiddlewareResponseHeadersAndBody populates headers and the body of the final response.
+func WriteMiddlewareResponseHeadersAndBody(grpcResp *http.Response, responseJson []byte, w http.ResponseWriter) ErrorJson {
+	var statusCodeHeader string
+	for h, vs := range grpcResp.Header {
+		// We don't want to expose any gRPC metadata in the HTTP response, so we skip forwarding metadata headers.
+		if strings.HasPrefix(h, grpc.MetadataPrefix) {
+			if h == grpc.WithPrefix(grpc.HttpCodeMetadataKey) {
+				statusCodeHeader = vs[0]
+			} else if strings.HasSuffix(h, api.VersionHeader) {
+				w.Header().Set(api.VersionHeader, vs[0])
+			}
+		} else {
+			for _, v := range vs {
+				w.Header().Set(h, v)
+			}
+		}
+	}
+	if !GrpcResponseIsEmpty(responseJson) {
+		w.Header().Set("Content-Length", strconv.Itoa(len(responseJson)))
+		if statusCodeHeader != "" {
+			code, err := strconv.Atoi(statusCodeHeader)
+			if err != nil {
+				return InternalServerErrorWithMessage(err, "could not parse status code")
+			}
+			w.WriteHeader(code)
+		} else {
+			w.WriteHeader(grpcResp.StatusCode)
+		}
+		if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(responseJson))); err != nil {
+			return InternalServerErrorWithMessage(err, "could not write response message")
+		}
+	} else {
+		w.Header().Set("Content-Length", "0")
+		w.WriteHeader(grpcResp.StatusCode)
+	}
+	return nil
+}
+
+// WriteError writes the error by manipulating headers and the body of the final response.
+func WriteError(w http.ResponseWriter, errJson ErrorJson, responseHeader http.Header) {
+	// Include custom error in the error JSON.
+	hasCustomError := false
+	if responseHeader != nil {
+		customError, ok := responseHeader[grpc.WithPrefix(grpc.CustomErrorMetadataKey)]
+		if ok {
+			hasCustomError = true
+			// Assume header has only one value and read the 0 index.
+			if err := json.Unmarshal([]byte(customError[0]), errJson); err != nil {
+				log.WithError(err).Error("Could not unmarshal custom error message")
+				return
+			}
+		}
+	}
+
+	var j []byte
+	if hasCustomError {
+		var err error
+		j, err = json.Marshal(errJson)
+		if err != nil {
+			log.WithError(err).Error("Could not marshal error message")
+			return
+		}
+	} else {
+		var err error
+		// We marshal the response body into a DefaultErrorJson if the custom error is not present.
+		// This is because the ErrorJson argument is the endpoint's error definition, which may contain custom fields.
+		// In such a scenario marhaling the endpoint's error would populate the resulting JSON
+		// with these fields even if they are not present in the gRPC header.
+		d := &DefaultErrorJson{
+			Message: errJson.Msg(),
+			Code:    errJson.StatusCode(),
+		}
+		j, err = json.Marshal(d)
+		if err != nil {
+			log.WithError(err).Error("Could not marshal error message")
+			return
+		}
+	}
+
+	w.Header().Set("Content-Length", strconv.Itoa(len(j)))
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(errJson.StatusCode())
+	if _, err := io.Copy(w, io.NopCloser(bytes.NewReader(j))); err != nil {
+		log.WithError(err).Error("Could not write error message")
+	}
+}
+
+// Cleanup performs final cleanup on the initial response from grpc-gateway.
+func Cleanup(grpcResponseBody io.ReadCloser) ErrorJson {
+	if err := grpcResponseBody.Close(); err != nil {
+		return InternalServerErrorWithMessage(err, "could not close response body")
+	}
+	return nil
+}
--- a/api/gateway/apimiddleware/process_request_test.go
+++ b/api/gateway/apimiddleware/process_request_test.go
@@ -0,0 +1,435 @@
+package apimiddleware
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/api"
+	"github.com/prysmaticlabs/prysm/v4/api/grpc"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/sirupsen/logrus/hooks/test"
+)
+
+type testRequestContainer struct {
+	TestString         string
+	TestHexString      string `hex:"true"`
+	TestEmptyHexString string `hex:"true"`
+	TestUint256String  string `uint256:"true"`
+}
+
+func defaultRequestContainer() *testRequestContainer {
+	return &testRequestContainer{
+		TestString:         "test string",
+		TestHexString:      "0x666F6F", // hex encoding of "foo"
+		TestEmptyHexString: "0x",
+		TestUint256String:  "4196",
+	}
+}
+
+type testResponseContainer struct {
+	TestString       string
+	TestHex          string `hex:"true"`
+	TestEmptyHex     string `hex:"true"`
+	TestAddress      string `address:"true"`
+	TestEmptyAddress string `address:"true"`
+	TestUint256      string `uint256:"true"`
+	TestEnum         string `enum:"true"`
+	TestTime         string `time:"true"`
+}
+
+func defaultResponseContainer() *testResponseContainer {
+	return &testResponseContainer{
+		TestString:       "test string",
+		TestHex:          "Zm9v", // base64 encoding of "foo"
+		TestEmptyHex:     "",
+		TestAddress:      "Zm9v",
+		TestEmptyAddress: "",
+		TestEnum:         "Test Enum",
+		TestTime:         "2006-01-02T15:04:05Z",
+
+		// base64 encoding of 4196 in little-endian
+		TestUint256: "ZBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
+	}
+}
+
+type testErrorJson struct {
+	Message     string
+	Code        int
+	CustomField string
+}
+
+// StatusCode returns the error's underlying error code.
+func (e *testErrorJson) StatusCode() int {
+	return e.Code
+}
+
+// Msg returns the error's underlying message.
+func (e *testErrorJson) Msg() string {
+	return e.Message
+}
+
+// SetCode sets the error's underlying error code.
+func (e *testErrorJson) SetCode(code int) {
+	e.Code = code
+}
+
+// SetMsg sets the error's underlying message.
+func (e *testErrorJson) SetMsg(msg string) {
+	e.Message = msg
+}
+
+func TestDeserializeRequestBodyIntoContainer(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		err := json.NewEncoder(&bodyJson).Encode(defaultRequestContainer())
+		require.NoError(t, err)
+
+		container := &testRequestContainer{}
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "test string", container.TestString)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("foo"))
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+
+	t.Run("unknown field", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("{\"foo\":\"foo\"}"))
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
+		assert.Equal(t, http.StatusBadRequest, errJson.StatusCode())
+	})
+}
+
+func TestProcessRequestContainerFields(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		container := defaultRequestContainer()
+
+		errJson := ProcessRequestContainerFields(container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "Zm9v", container.TestHexString)
+		assert.Equal(t, "", container.TestEmptyHexString)
+		assert.Equal(t, "ZBAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=", container.TestUint256String)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		errJson := ProcessRequestContainerFields("foo")
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not process request data"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+}
+
+func TestSetRequestBodyToRequestContainer(t *testing.T) {
+	var body bytes.Buffer
+	request := httptest.NewRequest("GET", "http://foo.example", &body)
+
+	errJson := SetRequestBodyToRequestContainer(defaultRequestContainer(), request)
+	require.Equal(t, true, errJson == nil)
+	container := &testRequestContainer{}
+	require.NoError(t, json.NewDecoder(request.Body).Decode(container))
+	assert.Equal(t, "test string", container.TestString)
+	contentLengthHeader, ok := request.Header["Content-Length"]
+	require.Equal(t, true, ok)
+	require.Equal(t, 1, len(contentLengthHeader), "wrong number of header values")
+	assert.Equal(t, "108", contentLengthHeader[0])
+	assert.Equal(t, int64(108), request.ContentLength)
+}
+
+func TestPrepareRequestForProxying(t *testing.T) {
+	middleware := &ApiProxyMiddleware{
+		GatewayAddress: "http://gateway.example",
+	}
+	// We will set some params to make the request more interesting.
+	endpoint := Endpoint{
+		Path:               "/{url_param}",
+		RequestURLLiterals: []string{"url_param"},
+		RequestQueryParams: []QueryParam{{Name: "query_param"}},
+	}
+	var body bytes.Buffer
+	request := httptest.NewRequest("GET", "http://foo.example?query_param=bar", &body)
+
+	errJson := middleware.PrepareRequestForProxying(endpoint, request)
+	require.Equal(t, true, errJson == nil)
+	assert.Equal(t, "http", request.URL.Scheme)
+	assert.Equal(t, middleware.GatewayAddress, request.URL.Host)
+	assert.Equal(t, "", request.RequestURI)
+}
+
+func TestReadGrpcResponseBody(t *testing.T) {
+	var b bytes.Buffer
+	b.Write([]byte("foo"))
+
+	body, jsonErr := ReadGrpcResponseBody(&b)
+	require.Equal(t, true, jsonErr == nil)
+	assert.Equal(t, "foo", string(body))
+}
+
+func TestHandleGrpcResponseError(t *testing.T) {
+	response := &http.Response{
+		StatusCode: 400,
+		Header: http.Header{
+			"Foo": []string{"foo"},
+			"Bar": []string{"bar"},
+		},
+	}
+	writer := httptest.NewRecorder()
+	errJson := &testErrorJson{
+		Message: "foo",
+		Code:    400,
+	}
+	b, err := json.Marshal(errJson)
+	require.NoError(t, err)
+
+	hasError, e := HandleGrpcResponseError(errJson, response, b, writer)
+	require.Equal(t, true, e == nil)
+	assert.Equal(t, true, hasError)
+	v, ok := writer.Header()["Foo"]
+	require.Equal(t, true, ok, "header not found")
+	require.Equal(t, 1, len(v), "wrong number of header values")
+	assert.Equal(t, "foo", v[0])
+	v, ok = writer.Header()["Bar"]
+	require.Equal(t, true, ok, "header not found")
+	require.Equal(t, 1, len(v), "wrong number of header values")
+	assert.Equal(t, "bar", v[0])
+	assert.Equal(t, 400, errJson.StatusCode())
+}
+
+func TestGrpcResponseIsEmpty(t *testing.T) {
+	t.Run("nil", func(t *testing.T) {
+		assert.Equal(t, true, GrpcResponseIsEmpty(nil))
+	})
+	t.Run("empty_slice", func(t *testing.T) {
+		assert.Equal(t, true, GrpcResponseIsEmpty(make([]byte, 0)))
+	})
+	t.Run("empty_brackets", func(t *testing.T) {
+		assert.Equal(t, true, GrpcResponseIsEmpty([]byte("{}")))
+	})
+	t.Run("non_empty", func(t *testing.T) {
+		assert.Equal(t, false, GrpcResponseIsEmpty([]byte("{\"foo\":\"bar\"})")))
+	})
+}
+
+func TestDeserializeGrpcResponseBodyIntoContainer(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		body, err := json.Marshal(defaultRequestContainer())
+		require.NoError(t, err)
+
+		container := &testRequestContainer{}
+		errJson := DeserializeGrpcResponseBodyIntoContainer(body, container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "test string", container.TestString)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("foo"))
+		errJson := DeserializeGrpcResponseBodyIntoContainer(bodyJson.Bytes(), &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not unmarshal response"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+}
+
+func TestProcessMiddlewareResponseFields(t *testing.T) {
+	t.Run("Ok", func(t *testing.T) {
+		container := defaultResponseContainer()
+
+		errJson := ProcessMiddlewareResponseFields(container)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, "0x666f6f", container.TestHex)
+		assert.Equal(t, "0x", container.TestEmptyHex)
+		assert.Equal(t, "0x0000000000000000000000000000000000666F6f", container.TestAddress)
+		assert.Equal(t, "0x", container.TestEmptyAddress)
+		assert.Equal(t, "4196", container.TestUint256)
+		assert.Equal(t, "test enum", container.TestEnum)
+		assert.Equal(t, "1136214245", container.TestTime)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		errJson := ProcessMiddlewareResponseFields("foo")
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not process response data"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+}
+
+func TestSerializeMiddlewareResponseIntoJson(t *testing.T) {
+	container := defaultResponseContainer()
+	j, errJson := SerializeMiddlewareResponseIntoJson(container)
+	assert.Equal(t, true, errJson == nil)
+	cToDeserialize := &testResponseContainer{}
+	require.NoError(t, json.Unmarshal(j, cToDeserialize))
+	assert.Equal(t, "test string", cToDeserialize.TestString)
+}
+
+func TestWriteMiddlewareResponseHeadersAndBody(t *testing.T) {
+	t.Run("GET", func(t *testing.T) {
+		response := &http.Response{
+			Header: http.Header{
+				"Foo": []string{"foo"},
+				grpc.WithPrefix(grpc.HttpCodeMetadataKey): []string{"204"},
+				grpc.WithPrefix(api.VersionHeader):        []string{"capella"},
+			},
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		v, ok := writer.Header()["Foo"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "foo", v[0])
+		v, ok = writer.Header()["Content-Length"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "224", v[0])
+		v, ok = writer.Header()["Eth-Consensus-Version"]
+		require.Equal(t, true, ok, "header not found")
+		assert.Equal(t, "capella", v[0])
+		assert.Equal(t, 204, writer.Code)
+		assert.DeepEqual(t, responseJson, writer.Body.Bytes())
+	})
+
+	t.Run("GET_no_grpc_status_code_header", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+	})
+
+	t.Run("GET_invalid_status_code", func(t *testing.T) {
+		response := &http.Response{
+			Header: http.Header{"Grpc-Metadata-Eth-Consensus-Version": []string{"capella"}},
+		}
+
+		// Set invalid status code.
+		response.Header[grpc.WithPrefix(grpc.HttpCodeMetadataKey)] = []string{"invalid"}
+		response.Header[grpc.WithPrefix(api.VersionHeader)] = []string{"capella"}
+
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, false, errJson == nil)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not parse status code"))
+		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
+	})
+
+	t.Run("POST", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+	})
+
+	t.Run("POST_with_response_body", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		container := defaultResponseContainer()
+		responseJson, err := json.Marshal(container)
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+		assert.DeepEqual(t, responseJson, writer.Body.Bytes())
+	})
+
+	t.Run("POST_with_empty_json_body", func(t *testing.T) {
+		response := &http.Response{
+			Header:     http.Header{},
+			StatusCode: 204,
+		}
+		responseJson, err := json.Marshal(struct{}{})
+		require.NoError(t, err)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		errJson := WriteMiddlewareResponseHeadersAndBody(response, responseJson, writer)
+		require.Equal(t, true, errJson == nil)
+		assert.Equal(t, 204, writer.Code)
+		assert.DeepEqual(t, []byte(nil), writer.Body.Bytes())
+		assert.Equal(t, "0", writer.Header()["Content-Length"][0])
+	})
+}
+
+func TestWriteError(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		responseHeader := http.Header{
+			grpc.WithPrefix(grpc.CustomErrorMetadataKey): []string{"{\"CustomField\":\"bar\"}"},
+		}
+		errJson := &testErrorJson{
+			Message: "foo",
+			Code:    500,
+		}
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		WriteError(writer, errJson, responseHeader)
+		v, ok := writer.Header()["Content-Length"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "48", v[0])
+		v, ok = writer.Header()["Content-Type"]
+		require.Equal(t, true, ok, "header not found")
+		require.Equal(t, 1, len(v), "wrong number of header values")
+		assert.Equal(t, "application/json", v[0])
+		assert.Equal(t, 500, writer.Code)
+		eDeserialize := &testErrorJson{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), eDeserialize))
+		assert.Equal(t, "foo", eDeserialize.Message)
+		assert.Equal(t, 500, eDeserialize.Code)
+		assert.Equal(t, "bar", eDeserialize.CustomField)
+	})
+
+	t.Run("invalid_custom_error_header", func(t *testing.T) {
+		logHook := test.NewGlobal()
+
+		responseHeader := http.Header{
+			grpc.WithPrefix(grpc.CustomErrorMetadataKey): []string{"invalid"},
+		}
+
+		WriteError(httptest.NewRecorder(), &testErrorJson{}, responseHeader)
+		assert.LogsContain(t, logHook, "Could not unmarshal custom error message")
+	})
+}
--- a/api/gateway/apimiddleware/structs.go
+++ b/api/gateway/apimiddleware/structs.go
@@ -0,0 +1,69 @@
+package apimiddleware
+
+import (
+	"net/http"
+
+	"github.com/pkg/errors"
+)
+
+// ---------------
+// Error handling.
+// ---------------
+
+// ErrorJson describes common functionality of all JSON error representations.
+type ErrorJson interface {
+	StatusCode() int
+	SetCode(code int)
+	Msg() string
+	SetMsg(msg string)
+}
+
+// DefaultErrorJson is a JSON representation of a simple error value, containing only a message and an error code.
+type DefaultErrorJson struct {
+	Message string `json:"message"`
+	Code    int    `json:"code"`
+}
+
+// InternalServerErrorWithMessage returns a DefaultErrorJson with 500 code and a custom message.
+func InternalServerErrorWithMessage(err error, message string) *DefaultErrorJson {
+	e := errors.Wrapf(err, message)
+	return &DefaultErrorJson{
+		Message: e.Error(),
+		Code:    http.StatusInternalServerError,
+	}
+}
+
+// InternalServerError returns a DefaultErrorJson with 500 code.
+func InternalServerError(err error) *DefaultErrorJson {
+	return &DefaultErrorJson{
+		Message: err.Error(),
+		Code:    http.StatusInternalServerError,
+	}
+}
+
+func TimeoutError() *DefaultErrorJson {
+	return &DefaultErrorJson{
+		Message: "Request timeout",
+		Code:    http.StatusRequestTimeout,
+	}
+}
+
+// StatusCode returns the error's underlying error code.
+func (e *DefaultErrorJson) StatusCode() int {
+	return e.Code
+}
+
+// Msg returns the error's underlying message.
+func (e *DefaultErrorJson) Msg() string {
+	return e.Message
+}
+
+// SetCode sets the error's underlying error code.
+func (e *DefaultErrorJson) SetCode(code int) {
+	e.Code = code
+}
+
+// SetMsg sets the error's underlying message.
+func (e *DefaultErrorJson) SetMsg(msg string) {
+	e.Message = msg
+}
--- a/api/gateway/gateway.go
+++ b/api/gateway/gateway.go
@@ -11,8 +11,9 @@ import (
 	"github.com/gorilla/mux"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v4/api/server"
+	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
 	"github.com/prysmaticlabs/prysm/v4/runtime"
+	"github.com/rs/cors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
@@ -33,6 +34,7 @@ type PbHandlerRegistration func(context.Context, *gwruntime.ServeMux, *grpc.Clie

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

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

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

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

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

@@ -158,6 +166,17 @@ 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 {
@@ -210,3 +229,13 @@ 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
@@ -10,6 +10,7 @@ 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"
@@ -17,18 +18,36 @@ 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,
@@ -44,6 +63,7 @@ func TestGateway_Customized(t *testing.T) {
 	require.Equal(t, 1, len(g.cfg.allowedOrigins))
 	assert.Equal(t, origins[0], g.cfg.allowedOrigins[0])
 	assert.Equal(t, size, g.cfg.maxCallRecvMsgSize)
+	assert.Equal(t, endpointFactory, g.cfg.apiMiddlewareEndpointFactory)
 }

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

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

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

+// WithApiMiddleware allows adding an API middleware proxy to the gateway.
+func WithApiMiddleware(endpointFactory apimiddleware.EndpointFactory) Option {
+	return func(g *Gateway) error {
+		g.cfg.apiMiddlewareEndpointFactory = endpointFactory
+		return nil
+	}
+}
+
 // WithTimeout allows changing the timeout value for API calls.
 func WithTimeout(seconds uint64) Option {
 	return func(g *Gateway) error {
--- a/api/server/BUILD.bazel
+++ b/api/server/BUILD.bazel
@@ -3,22 +3,16 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = [
-        "error.go",
        "middleware.go",
        "util.go",
    ],
    importpath = "github.com/prysmaticlabs/prysm/v4/api/server",
    visibility = ["//visibility:public"],
-    deps = [
-        "@com_github_gorilla_mux//:go_default_library",
-        "@com_github_rs_cors//:go_default_library",
-    ],
 )

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

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

-// NormalizeQueryValuesHandler normalizes an input query of "key=value1,value2,value3" to "key=value1&key=value2&key=value3"
 func NormalizeQueryValuesHandler(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		query := r.URL.Query()
@@ -17,16 +13,3 @@ func NormalizeQueryValuesHandler(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
-
-// CorsHandler sets the cors settings on api endpoints
-func CorsHandler(allowOrigins []string) mux.MiddlewareFunc {
-	c := cors.New(cors.Options{
-		AllowedOrigins:   allowOrigins,
-		AllowedMethods:   []string{http.MethodPost, http.MethodGet, http.MethodDelete, http.MethodOptions},
-		AllowCredentials: true,
-		MaxAge:           600,
-		AllowedHeaders:   []string{"*"},
-	})
-
-	return c.Handler
-}
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -26,7 +26,6 @@ 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",
@@ -50,10 +49,10 @@ go_library(
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/time:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
-        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/filters:go_default_library",
+        "//beacon-chain/db/kv:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/forkchoice:go_default_library",
        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
@@ -100,22 +99,26 @@ go_library(
    ],
 )

-go_test(
+test_suite(
    name = "go_default_test",
+    tests = [
+        ":go_raceoff_test",
+        ":go_raceon_test",
+    ],
+)
+
+go_test(
+    name = "go_raceoff_test",
    size = "medium",
    srcs = [
        "blockchain_test.go",
-        "chain_info_norace_test.go",
        "chain_info_test.go",
        "checktags_test.go",
-        "error_test.go",
        "execution_engine_test.go",
        "forkchoice_update_execution_test.go",
        "head_sync_committee_info_test.go",
        "head_test.go",
-        "init_sync_process_block_test.go",
        "init_test.go",
-        "lightclient_test.go",
        "log_test.go",
        "metrics_test.go",
        "mock_test.go",
@@ -124,67 +127,98 @@ go_test(
        "process_block_test.go",
        "receive_attestation_test.go",
        "receive_block_test.go",
-        "service_norace_test.go",
        "service_test.go",
        "setup_test.go",
        "weak_subjectivity_checks_test.go",
    ],
    embed = [":go_default_library"],
    gotags = ["develop"],
-    tags = ["CI_race_detection"],
    deps = [
        "//async/event:go_default_library",
        "//beacon-chain/blockchain/testing:go_default_library",
-        "//beacon-chain/cache:go_default_library",
        "//beacon-chain/cache/depositcache:go_default_library",
        "//beacon-chain/core/blocks:go_default_library",
-        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
-        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
-        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/testing:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/execution/testing:go_default_library",
-        "//beacon-chain/forkchoice:go_default_library",
-        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
        "//beacon-chain/forkchoice/types:go_default_library",
-        "//beacon-chain/operations/attestations:go_default_library",
-        "//beacon-chain/operations/blstoexec:go_default_library",
-        "//beacon-chain/operations/slashings:go_default_library",
-        "//beacon-chain/operations/voluntaryexits:go_default_library",
        "//beacon-chain/p2p:go_default_library",
-        "//beacon-chain/startup:go_default_library",
-        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/state-native:go_default_library",
-        "//beacon-chain/state/stategen:go_default_library",
-        "//config/features:go_default_library",
+        "//beacon-chain/state/stateutil:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/interfaces:go_default_library",
-        "//consensus-types/primitives:go_default_library",
+        "//consensus-types/blocks/testing:go_default_library",
        "//container/trie:go_default_library",
-        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
-        "//proto/engine/v1:go_default_library",
-        "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime/version:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
-        "//time:go_default_library",
-        "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
+        "@in_gopkg_d4l3k_messagediff_v1//:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
+        "@org_golang_x_net//context:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_raceon_test",
+    srcs = [
+        "chain_info_norace_test.go",
+        "checktags_test.go",
+        "init_test.go",
+        "mock_test.go",
+        "receive_block_test.go",
+        "service_norace_test.go",
+        "setup_test.go",
+    ],
+    embed = [":go_default_library"],
+    gc_goopts = [
+        # Go 1.14 enables checkptr by default when building with -race or -msan. There is a pointer
+        # issue in boltdb, so must disable checkptr at compile time. This flag can be removed once
+        # the project is migrated to etcd's version of boltdb and the issue has been fixed.
+        # See: https://github.com/etcd-io/bbolt/issues/187.
+        "-d=checkptr=0",
+    ],
+    gotags = ["develop"],
+    race = "on",
+    tags = ["race_on"],
+    deps = [
+        "//async/event:go_default_library",
+        "//beacon-chain/blockchain/testing:go_default_library",
+        "//beacon-chain/cache/depositcache:go_default_library",
+        "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/transition:go_default_library",
+        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/execution:go_default_library",
+        "//beacon-chain/execution/testing:go_default_library",
+        "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/blocks/testing:go_default_library",
+        "//container/trie:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_ethereum_go_ethereum//:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
-        "@com_github_holiman_uint256//:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
+        "@org_golang_x_net//context:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/chain_info.go
+++ b/beacon-chain/blockchain/chain_info.go
@@ -75,7 +75,6 @@ type HeadFetcher interface {
 	HeadPublicKeyToValidatorIndex(pubKey [fieldparams.BLSPubkeyLength]byte) (primitives.ValidatorIndex, bool)
 	HeadValidatorIndexToPublicKey(ctx context.Context, index primitives.ValidatorIndex) ([fieldparams.BLSPubkeyLength]byte, error)
 	ChainHeads() ([][32]byte, []primitives.Slot)
-	TargetRootForEpoch([32]byte, primitives.Epoch) ([32]byte, error)
 	HeadSyncCommitteeFetcher
 	HeadDomainFetcher
 }
@@ -340,10 +339,6 @@ func (s *Service) IsOptimistic(_ context.Context) (bool, error) {
 		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
@@ -469,13 +464,6 @@ func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool,
 	return !isCanonical, nil
 }

-// TargetRootForEpoch wraps the corresponding method in forkchoice
-func (s *Service) TargetRootForEpoch(root [32]byte, epoch primitives.Epoch) ([32]byte, error) {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.TargetRootForEpoch(root, epoch)
-}
-
 // Ancestor returns the block root of an ancestry block from the input block root.
 //
 // Spec pseudocode definition:
@@ -542,10 +530,3 @@ func (s *Service) recoverStateSummary(ctx context.Context, blockRoot [32]byte) (
 func (s *Service) BlockBeingSynced(root [32]byte) bool {
 	return s.blockBeingSynced.isSyncing(root)
 }
-
-// RecentBlockSlot returns block slot form fork choice store
-func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.Slot(root)
-}
--- a/beacon-chain/blockchain/chain_info_forkchoice.go
+++ b/beacon-chain/blockchain/chain_info_forkchoice.go
@@ -22,13 +22,6 @@ func (s *Service) GetProposerHead() [32]byte {
 	return s.cfg.ForkChoiceStore.GetProposerHead()
 }

-// ShouldOverrideFCU returns the corresponding value from forkchoice
-func (s *Service) ShouldOverrideFCU() bool {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.ShouldOverrideFCU()
-}
-
 // SetForkChoiceGenesisTime sets the genesis time in Forkchoice
 func (s *Service) SetForkChoiceGenesisTime(timestamp uint64) {
 	s.cfg.ForkChoiceStore.Lock()
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -429,11 +429,6 @@ func TestService_IsOptimistic(t *testing.T) {
 	opt, err = c.IsOptimistic(ctx)
 	require.NoError(t, err)
 	require.Equal(t, true, opt)
-
-	// If head is nil, for some reason, an error should be returned rather than panic.
-	c = &Service{}
-	_, err = c.IsOptimistic(ctx)
-	require.ErrorIs(t, err, ErrNilHead)
 }

 func TestService_IsOptimisticBeforeBellatrix(t *testing.T) {
--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -28,8 +28,6 @@ var (
 	// ErrNotCheckpoint is returned when a given checkpoint is not a
 	// checkpoint in any chain known to forkchoice
 	ErrNotCheckpoint = errors.New("not a checkpoint in forkchoice")
-	// ErrNilHead is returned when no head is present in the blockchain service.
-	ErrNilHead = errors.New("nil head")
 )

 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")
--- a/beacon-chain/blockchain/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"
@@ -32,18 +32,21 @@ const blobCommitmentVersionKZG uint8 = 0x01

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

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

-	if arg.headBlock.IsNil() {
-		log.Error("Head block is nil")
-		return nil, nil
-	}
-	headBlk := arg.headBlock.Block()
+	headBlk := arg.headBlock
 	if headBlk == nil || headBlk.IsNil() || headBlk.Body().IsNil() {
 		log.Error("Head block is nil")
 		return nil, nil
@@ -69,10 +72,11 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		SafeBlockHash:      justifiedHash[:],
 		FinalizedBlockHash: finalizedHash[:],
 	}
-	if arg.attributes == nil {
-		arg.attributes = payloadattribute.EmptyWithVersion(headBlk.Version())
-	}
-	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, arg.attributes)
+
+	nextSlot := s.CurrentSlot() + 1 // Cache payload ID for next slot proposer.
+	hasAttr, attr, proposerId := s.getPayloadAttribute(ctx, arg.headState, nextSlot, arg.headRoot[:])
+
+	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, attr)
 	if err != nil {
 		switch err {
 		case execution.ErrAcceptedSyncingPayloadStatus:
@@ -118,11 +122,10 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 				log.WithError(err).Error("Could not get head state")
 				return nil, nil
 			}
-			pid, err := s.notifyForkchoiceUpdate(ctx, &fcuConfig{
-				headState:  st,
-				headRoot:   r,
-				headBlock:  b,
-				attributes: arg.attributes,
+			pid, err := s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
+				headState: st,
+				headRoot:  r,
+				headBlock: b.Block(),
 			})
 			if err != nil {
 				return nil, err // Returning err because it's recursive here.
@@ -150,9 +153,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 		log.WithError(err).Error("Could not set head root to valid")
 		return nil, nil
 	}
-	// If the forkchoice update call has an attribute, update the payload ID cache.
-	hasAttr := arg.attributes != nil && !arg.attributes.IsEmpty()
-	nextSlot := s.CurrentSlot() + 1
+	// If the forkchoice update call has an attribute, update the proposer payload ID cache.
 	if hasAttr && payloadID != nil {
 		var pId [8]byte
 		copy(pId[:], payloadID[:])
@@ -161,7 +162,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			"headSlot":  headBlk.Slot(),
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
-		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
+		s.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(nextSlot, proposerId, pId, arg.headRoot)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
@@ -276,50 +277,56 @@ func (s *Service) pruneInvalidBlock(ctx context.Context, root, parentRoot, lvh [

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

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

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

-	return attr
+	return true, attr, proposerID
 }

 // removeInvalidBlockAndState removes the invalid block, blob and its corresponding state from the cache and DB.
@@ -387,7 +394,10 @@ 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
 		}
-		// TODO: Remove blob here
+		// No op if the sidecar does not exist.
+		if err := s.cfg.BeaconDB.DeleteBlobSidecars(ctx, root); err != nil {
+			return err
+		}
 	}
 	return nil
 }
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -26,10 +26,11 @@ 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, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
 	ctx, beaconDB, fcs := tr.ctx, tr.db, tr.fcs

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

 	// Cache hit, advance state, has fee recipient
 	suggestedAddr := common.HexToAddress("123")
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	attr = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
-	require.Equal(t, false, attr.IsEmpty())
+	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []primitives.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
 	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
 	a, err = attr.Withdrawals()
 	require.NoError(t, err)
@@ -1102,35 +1112,3 @@ func TestKZGCommitmentToVersionedHashes(t *testing.T) {
 	require.Equal(t, vhs[0].String(), vh0)
 	require.Equal(t, vhs[1].String(), vh1)
 }
-
-func TestComputePayloadAttribute(t *testing.T) {
-	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
-	ctx := tr.ctx
-
-	st, _ := util.DeterministicGenesisStateBellatrix(t, 1)
-
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, Index: 0})
-	// Cache hit, advance state, no fee recipient
-	slot := primitives.Slot(1)
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	cfg := &postBlockProcessConfig{
-		ctx:       ctx,
-		blockRoot: [32]byte{'a'},
-	}
-	fcu := &fcuConfig{
-		headState:     st,
-		proposingSlot: slot,
-		headRoot:      [32]byte{},
-	}
-	require.NoError(t, service.computePayloadAttributes(cfg, fcu))
-	require.Equal(t, false, fcu.attributes.IsEmpty())
-	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(fcu.attributes.SuggestedFeeRecipient()).String())
-
-	// Cache hit, advance state, has fee recipient
-	suggestedAddr := common.HexToAddress("123")
-	service.cfg.TrackedValidatorsCache.Set(cache.TrackedValidator{Active: true, FeeRecipient: primitives.ExecutionAddress(suggestedAddr), Index: 0})
-	service.cfg.PayloadIDCache.Set(slot, [32]byte{}, [8]byte{})
-	require.NoError(t, service.computePayloadAttributes(cfg, fcu))
-	require.Equal(t, false, fcu.attributes.IsEmpty())
-	require.Equal(t, suggestedAddr, common.BytesToAddress(fcu.attributes.SuggestedFeeRecipient()))
-}
--- a/beacon-chain/blockchain/forkchoice_update_execution.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution.go
@@ -8,15 +8,20 @@ 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()
@@ -44,69 +49,48 @@ func (s *Service) getStateAndBlock(ctx context.Context, r [32]byte) (state.Beaco
 	return headState, newHeadBlock, nil
 }

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

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

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

 // shouldOverrideFCU checks whether the incoming block is still subject to being
--- a/beacon-chain/blockchain/forkchoice_update_execution_test.go
+++ b/beacon-chain/blockchain/forkchoice_update_execution_test.go
@@ -17,6 +17,15 @@ 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)
@@ -58,14 +67,33 @@ func TestService_getHeadStateAndBlock(t *testing.T) {
 }

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

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

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

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

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

 func TestShouldOverrideFCU(t *testing.T) {
--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -276,7 +276,7 @@ func (s *Service) headBlock() (interfaces.ReadOnlySignedBeaconBlock, error) {
 // It does a full copy on head state for immutability.
 // This is a lock free version.
 func (s *Service) headState(ctx context.Context) state.BeaconState {
-	_, span := trace.StartSpan(ctx, "blockChain.headState")
+	ctx, span := trace.StartSpan(ctx, "blockChain.headState")
 	defer span.End()

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

 	return s.head.state
--- a/beacon-chain/blockchain/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 = [
-        "//consensus-types/blocks:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
@@ -24,10 +24,8 @@ go_test(
    ],
    embed = [":go_default_library"],
    deps = [
-        "//consensus-types/blocks:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
        "//testing/require:go_default_library",
-        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/kzg/validation.go
+++ b/beacon-chain/blockchain/kzg/validation.go
@@ -1,28 +1,32 @@
 package kzg

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

-// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
-func Verify(sidecars ...blocks.ROBlob) error {
-	if len(sidecars) == 0 {
+// IsDataAvailable checks that
+// - all blobs in the block are available
+// - Expected KZG commitments match the number of blobs in the block
+// - That the number of proofs match the number of blobs
+// - That the proofs are verified against the KZG commitments
+func IsDataAvailable(commitments [][]byte, sidecars []*ethpb.DeprecatedBlobSidecar) error {
+	if len(commitments) != len(sidecars) {
+		return fmt.Errorf("could not check data availability, expected %d commitments, obtained %d",
+			len(commitments), len(sidecars))
+	}
+	if len(commitments) == 0 {
 		return nil
 	}
-	if len(sidecars) == 1 {
-		return kzgContext.VerifyBlobKZGProof(
-			bytesToBlob(sidecars[0].Blob),
-			bytesToCommitment(sidecars[0].KzgCommitment),
-			bytesToKZGProof(sidecars[0].KzgProof))
-	}
-	blobs := make([]GoKZG.Blob, len(sidecars))
-	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
-	proofs := make([]GoKZG.KZGProof, len(sidecars))
+	blobs := make([]GoKZG.Blob, len(commitments))
+	proofs := make([]GoKZG.KZGProof, len(commitments))
+	cmts := make([]GoKZG.KZGCommitment, len(commitments))
 	for i, sidecar := range sidecars {
 		blobs[i] = bytesToBlob(sidecar.Blob)
-		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
 		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
+		cmts[i] = bytesToCommitment(commitments[i])
 	}
 	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
 }
--- a/beacon-chain/blockchain/kzg/validation_test.go
+++ b/beacon-chain/blockchain/kzg/validation_test.go
@@ -1,66 +1,17 @@
 package kzg

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

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

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

 func TestBytesToAny(t *testing.T) {
@@ -72,13 +23,3 @@ 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, daWaitedTime time.Duration) error {
+func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte, justified, finalized *ethpb.Checkpoint, receivedTime time.Time, genesisTime uint64) error {
 	startTime, err := slots.ToTime(genesisTime, block.Slot())
 	if err != nil {
 		return err
@@ -93,7 +93,7 @@ func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte
 			"parentRoot":                fmt.Sprintf("0x%s...", hex.EncodeToString(parentRoot[:])[:8]),
 			"version":                   version.String(block.Version()),
 			"sinceSlotStartTime":        prysmTime.Now().Sub(startTime),
-			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime) - daWaitedTime,
+			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime),
 			"deposits":                  len(block.Body().Deposits()),
 		}
 		log.WithFields(lf).Debug("Synced new block")
--- a/beacon-chain/blockchain/metrics.go
+++ b/beacon-chain/blockchain/metrics.go
@@ -358,7 +358,6 @@ func reportEpochMetrics(ctx context.Context, postState, headState state.BeaconSt
 	for name, val := range refMap {
 		stateTrieReferences.WithLabelValues(name).Set(float64(val))
 	}
-	postState.RecordStateMetrics()

 	return nil
 }
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -69,18 +69,10 @@ func WithDepositCache(c cache.DepositCache) Option {
 	}
 }

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

-// WithClockSynchronizer sets the ClockSetter/ClockWaiter values to be used by services that need to block until
+// WithClockSychronizer sets the ClockSetter/ClockWaiter values to be used by services that need to block until
 // the genesis timestamp is known (ClockWaiter) or which determine the genesis timestamp (ClockSetter).
 func WithClockSynchronizer(gs *startup.ClockSynchronizer) Option {
 	return func(s *Service) error {
--- 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)}))

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

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

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

 	assert.Equal(t, 2*params.BeaconConfig().SlotsPerEpoch, s2.Slot(), "Unexpected state slot")
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -12,7 +12,6 @@ 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/db/filesystem"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
@@ -29,6 +28,7 @@ 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"
 )

@@ -41,67 +41,106 @@ const depositDeadline = 20 * time.Second
 // This defines size of the upper bound for initial sync block cache.
 var initialSyncBlockCacheSize = uint64(2 * params.BeaconConfig().SlotsPerEpoch)

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

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

-	s.InsertSlashingsToForkChoiceStore(ctx, cfg.signed.Block().Body().AttesterSlashings())
-	if cfg.isValidPayload {
-		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, cfg.blockRoot); err != nil {
+	s.InsertSlashingsToForkChoiceStore(ctx, signed.Block().Body().AttesterSlashings())
+	if isValidPayload {
+		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, blockRoot); err != nil {
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
+
 	start := time.Now()
-	cfg.headRoot, err = s.cfg.ForkChoiceStore.Head(ctx)
+	headRoot, err := s.cfg.ForkChoiceStore.Head(ctx)
 	if err != nil {
 		log.WithError(err).Warn("Could not update head")
 	}
+	if blockRoot != headRoot {
+		receivedWeight, err := s.cfg.ForkChoiceStore.Weight(blockRoot)
+		if err != nil {
+			log.WithField("root", fmt.Sprintf("%#x", blockRoot)).Warn("could not determine node weight")
+		}
+		headWeight, err := s.cfg.ForkChoiceStore.Weight(headRoot)
+		if err != nil {
+			log.WithField("root", fmt.Sprintf("%#x", headRoot)).Warn("could not determine node weight")
+		}
+		log.WithFields(logrus.Fields{
+			"receivedRoot":   fmt.Sprintf("%#x", blockRoot),
+			"receivedWeight": receivedWeight,
+			"headRoot":       fmt.Sprintf("%#x", headRoot),
+			"headWeight":     headWeight,
+		}).Debug("Head block is not the received block")
+	}
 	newBlockHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
-	if cfg.headRoot != cfg.blockRoot {
-		s.logNonCanonicalBlockReceived(cfg.blockRoot, cfg.headRoot)
-		return nil
+
+	// 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 err := s.getFCUArgs(cfg, fcuArgs); err != nil {
-		log.WithError(err).Error("Could not get forkchoice update argument")
-		return nil
+
+	optimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(blockRoot)
+	if err != nil {
+		log.WithError(err).Debug("Could not check if block is optimistic")
+		optimistic = true
 	}
-	if err := s.sendFCU(cfg, fcuArgs); err != nil {
-		return errors.Wrap(err, "could not send FCU to engine")
+
+	// 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
 }

@@ -123,7 +162,7 @@ func getStateVersionAndPayload(st state.BeaconState) (int, interfaces.ExecutionD
 	return preStateVersion, preStateHeader, nil
 }

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

@@ -226,8 +265,8 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 				return err
 			}
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
-			return errors.Wrapf(err, "could not validate blob data availability at slot %d", b.Block().Slot())
+		if err := s.databaseDACheck(ctx, b); err != nil {
+			return errors.Wrap(err, "could not validate blob data availability")
 		}
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
 			JustifiedCheckpoint: jCheckpoints[i],
@@ -283,10 +322,10 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
-	arg := &fcuConfig{
+	arg := &notifyForkchoiceUpdateArg{
 		headState: preState,
 		headRoot:  lastBR,
-		headBlock: lastB,
+		headBlock: lastB.Block(),
 	}
 	if _, err := s.notifyForkchoiceUpdate(ctx, arg); err != nil {
 		return err
@@ -294,6 +333,37 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }

+func commitmentsToCheck(b consensusblocks.ROBlock, current primitives.Slot) [][]byte {
+	if b.Version() < version.Deneb {
+		return nil
+	}
+	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	if !params.WithinDAPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(current)) {
+		return nil
+	}
+	kzgCommitments, err := b.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil
+	}
+	return kzgCommitments
+}
+
+func (s *Service) databaseDACheck(ctx context.Context, b consensusblocks.ROBlock) error {
+	commitments := commitmentsToCheck(b, s.CurrentSlot())
+	if len(commitments) == 0 {
+		return nil
+	}
+	missing, err := missingIndices(s.blobStorage, b.Root(), commitments)
+	if err != nil {
+		return err
+	}
+	if len(missing) == 0 {
+		return nil
+	}
+	// TODO: don't worry that this error isn't informative, it will be superceded by a detailed sidecar cache error.
+	return errors.New("not all kzg commitments are available")
+}
+
 func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.BeaconState) error {
 	e := coreTime.CurrentEpoch(st)
 	if err := helpers.UpdateCommitteeCache(ctx, st, e); err != nil {
@@ -311,24 +381,10 @@ 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
-	target, err := s.cfg.ForkChoiceStore.TargetRootForEpoch(r, e-1)
-	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
 }

@@ -595,18 +651,16 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	if err := transition.UpdateNextSlotCache(ctx, lastRoot, lastState); err != nil {
 		log.WithError(err).Debug("could not update next slot state cache")
 	}
-	// handleEpochBoundary requires a forkchoice lock to obtain the target root.
-	s.cfg.ForkChoiceStore.RLock()
 	if err := s.handleEpochBoundary(ctx, currentSlot, headState, headRoot[:]); err != nil {
 		log.WithError(err).Error("lateBlockTasks: could not update epoch boundary caches")
 	}
-	s.cfg.ForkChoiceStore.RUnlock()
-	// 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 {
+	// 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
 	}
+
 	s.headLock.RLock()
 	headBlock, err := s.headBlock()
 	if err != nil {
@@ -615,19 +669,12 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 		return
 	}
 	s.headLock.RUnlock()
-
-	fcuArgs := &fcuConfig{
+	s.cfg.ForkChoiceStore.RLock()
+	_, err = s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
 		headState: headState,
 		headRoot:  headRoot,
-		headBlock: headBlock,
-	}
-	fcuArgs.attributes = s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
-	// return early if we are not proposing next slot
-	if fcuArgs.attributes.IsEmpty() {
-		return
-	}
-	s.cfg.ForkChoiceStore.RLock()
-	_, err = s.notifyForkchoiceUpdate(ctx, fcuArgs)
+		headBlock: headBlock.Block(),
+	})
 	s.cfg.ForkChoiceStore.RUnlock()
 	if err != nil {
 		log.WithError(err).Debug("could not perform late block tasks: failed to update forkchoice with engine")
--- a/beacon-chain/blockchain/process_block_helpers.go
+++ b/beacon-chain/blockchain/process_block_helpers.go
@@ -3,13 +3,9 @@ package blockchain
 import (
 	"context"
 	"fmt"
-	"time"

 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
-	"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"
@@ -19,8 +15,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	mathutil "github.com/prysmaticlabs/prysm/v4/math"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )

@@ -29,127 +25,6 @@ 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
-	}
-	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,
-		},
-	})
-}
-
-// 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.
@@ -171,7 +46,7 @@ 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.BeaconConfig().MaximumGossipClockDisparityDuration()); err != nil {
+	if err := slots.VerifyTime(uint64(s.genesisTime.Unix()), b.Slot(), params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
 		return nil, err
 	}

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

 import (
+	"bytes"
 	"context"
 	"fmt"
 	"math/big"
@@ -16,7 +17,6 @@ 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"
@@ -40,6 +40,7 @@ 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"
 )

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

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

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

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

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

 	aHash := common.BytesToHash([]byte("a"))
@@ -923,10 +924,8 @@ 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),
 			},
 		},
 		{
@@ -970,7 +969,6 @@ 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),
@@ -1113,7 +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(&postBlockProcessConfig{ctx, wsb1, r1, [32]byte{}, postState, true}))
+			require.NoError(t, service.postBlockProcess(ctx, wsb1, r1, postState, true))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1123,7 +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(&postBlockProcessConfig{ctx, wsb2, r2, [32]byte{}, postState, true}))
+			require.NoError(t, service.postBlockProcess(ctx, wsb2, r2, postState, true))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1133,7 +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(&postBlockProcessConfig{ctx, wsb3, r3, [32]byte{}, postState, true}))
+			require.NoError(t, service.postBlockProcess(ctx, wsb3, r3, postState, true))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1143,7 +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(&postBlockProcessConfig{ctx, wsb4, r4, [32]byte{}, postState, true}))
+			require.NoError(t, service.postBlockProcess(ctx, wsb4, r4, postState, true))
 			lock.Unlock()
 			wg.Done()
 		}()
@@ -1218,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
+		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
 	}

 	for i := 6; i < 12; i++ {
@@ -1236,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, root, postState, false)
 		require.NoError(t, err)
 	}

@@ -1255,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, root, postState, false)
 		require.NoError(t, err)
 	}
 	// Check that we haven't justified the second epoch yet
@@ -1277,7 +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(&postBlockProcessConfig{ctx, wsb, firstInvalidRoot, [32]byte{}, postState, false})
+	err = service.postBlockProcess(ctx, wsb, firstInvalidRoot, postState, false)
 	require.NoError(t, err)
 	jc = service.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	require.Equal(t, primitives.Epoch(2), jc.Epoch)
@@ -1305,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+	err = service.postBlockProcess(ctx, wsb, root, 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
@@ -1334,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
+	err = service.postBlockProcess(ctx, wsb, root, 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
@@ -1396,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
+		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
 	}

 	for i := 6; i < 12; i++ {
@@ -1414,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, root, postState, false)
 		require.NoError(t, err)
 	}

@@ -1434,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, root, postState, false)
 		require.NoError(t, err)
 	}
 	// Check that we haven't justified the second epoch yet
@@ -1456,7 +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(&postBlockProcessConfig{ctx, wsb, firstInvalidRoot, [32]byte{}, postState, false})
+	err = service.postBlockProcess(ctx, wsb, firstInvalidRoot, postState, false)
 	require.NoError(t, err)
 	jc = service.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	require.Equal(t, primitives.Epoch(2), jc.Epoch)
@@ -1512,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
+	err = service.postBlockProcess(ctx, wsb, root, 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
@@ -1576,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
+		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
 	}

 	for i := 6; i < 12; i++ {
@@ -1595,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, root, postState, false)
 		require.NoError(t, err)
 	}

@@ -1614,7 +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(&postBlockProcessConfig{ctx, wsb, lastValidRoot, [32]byte{}, postState, false})
+	err = service.postBlockProcess(ctx, wsb, lastValidRoot, postState, false)
 	require.NoError(t, err)
 	// save the post state and the payload Hash of this block since it will
 	// be the LVH
@@ -1641,7 +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(&postBlockProcessConfig{ctx, wsb, invalidRoots[i-13], [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, invalidRoots[i-13], postState, false)
 		require.NoError(t, err)
 	}
 	// Check that we have justified the second epoch
@@ -1706,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true}))
+	require.NoError(t, service.postBlockProcess(ctx, wsb, root, 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)
@@ -1729,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
+		err = service.postBlockProcess(ctx, wsb, root, postState, true)
 		require.NoError(t, err)
 		st, err = service.cfg.StateGen.StateByRoot(ctx, root)
 		require.NoError(t, err)
@@ -1755,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, true})
+	err = service.postBlockProcess(ctx, wsb, root, postState, true)
 	require.NoError(t, err)
 	require.Equal(t, root, service.cfg.ForkChoiceStore.CachedHeadRoot())
 	sjc = service.CurrentJustifiedCheckpt()
@@ -1811,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
+		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
 	}

 	for i := 6; i < 12; i++ {
@@ -1829,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false})
+		err = service.postBlockProcess(ctx, wsb, root, postState, false)
 		require.NoError(t, err)
 	}

@@ -1848,7 +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(&postBlockProcessConfig{ctx, wsb, lastValidRoot, [32]byte{}, postState, false})
+	err = service.postBlockProcess(ctx, wsb, lastValidRoot, postState, false)
 	require.NoError(t, err)
 	// save the post state and the payload Hash of this block since it will
 	// be the LVH
@@ -1877,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
+		require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))
 		require.NoError(t, service.updateJustificationOnBlock(ctx, preState, postState, currStoreJustifiedEpoch))
 		_, err = service.updateFinalizationOnBlock(ctx, preState, postState, currStoreFinalizedEpoch)
 		require.NoError(t, err)
@@ -1948,7 +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}, &das.MockAvailabilityStore{}))
+	require.NoError(t, service.onBlockBatch(ctx, []consensusblocks.ROBlock{rwsb}))
 	// 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)
@@ -1992,7 +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(&postBlockProcessConfig{ctx, wsb, root, [32]byte{}, postState, false}))
+	require.NoError(t, service.postBlockProcess(ctx, wsb, root, postState, false))

 	st, err = service.HeadState(ctx)
 	require.NoError(t, err)
@@ -2047,10 +2045,78 @@ 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
+	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]))
+			}
+		})
+	}
+}
+
 func TestMissingIndices(t *testing.T) {
 	cases := []struct {
 		name     string
@@ -2131,35 +2197,6 @@ 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
@@ -9,6 +9,7 @@ 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"
@@ -52,11 +53,15 @@ 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 {
-	r, err := s.TargetRootForEpoch([32]byte(a.Data.BeaconBlockRoot), a.Data.Target.Epoch)
+	targetSlot, err := slots.EpochStart(a.Data.Target.Epoch)
 	if err != nil {
 		return err
 	}
-	if !bytes.Equal(a.Data.Target.Root, r[:]) {
+	r, err := s.Ancestor(ctx, a.Data.BeaconBlockRoot, targetSlot)
+	if err != nil {
+		return err
+	}
+	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
@@ -120,43 +125,37 @@ 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.BeaconConfig().MaximumGossipClockDisparityDuration()
-	disparity += reorgLateBlockCountAttestations
-
+	disparity := params.BeaconNetworkConfig().MaximumGossipClockDisparity
+	if !features.Get().DisableReorgLateBlocks {
+		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")
-		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
+		// Fallback to our current head root in the event of a failure.
+		s.headLock.RLock()
+		newHeadRoot = s.headRoot()
+		s.headLock.RUnlock()
 	}
 	newAttHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
-	fcuArgs := &fcuConfig{
-		headState:     headState,
-		headRoot:      newHeadRoot,
-		headBlock:     headBlock,
-		proposingSlot: proposingSlot,
-	}
-	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 {
+
+	changed, err := s.forkchoiceUpdateWithExecution(s.ctx, newHeadRoot, proposingSlot)
+	if err != nil {
 		log.WithError(err).Error("could not update forkchoice")
 	}
+	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()
+	}
 }

 // This processes fork choice attestations from the pool to account for validator votes and fork choice.
--- a/beacon-chain/blockchain/receive_attestation_test.go
+++ b/beacon-chain/blockchain/receive_attestation_test.go
@@ -36,28 +36,50 @@ func TestAttestationCheckPtState_FarFutureSlot(t *testing.T) {
 	require.ErrorContains(t, "exceeds max allowed value relative to the local clock", err)
 }

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

-	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)
+	b32 := util.NewBeaconBlock()
+	b32.Block.Slot = 32
+	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b32)
+	r32, err := b32.Block.HashTreeRoot()
 	require.NoError(t, err)
-	require.NoError(t, f.InsertNode(ctx, state, r32))
-
-	state, r33, err := prepareForkchoiceState(ctx, 33, [32]byte{'b'}, r32, params.BeaconConfig().ZeroHash, fc, fc)
+	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)
-	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{'c'}
+	a.Data.Target.Root = []byte{'a'}
 	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")
 }
@@ -112,7 +134,7 @@ 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(&postBlockProcessConfig{ctx, wsb, tRoot, [32]byte{}, postState, false}))
+	require.NoError(t, service.postBlockProcess(ctx, wsb, tRoot, postState, false))
 	copied, err = service.cfg.StateGen.StateByRoot(ctx, tRoot)
 	require.NoError(t, err)
 	require.Equal(t, 2, fcs.NodeCount())
@@ -168,7 +190,7 @@ 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(&postBlockProcessConfig{ctx, wsb, tRoot, [32]byte{}, postState, false}))
+	require.NoError(t, service.postBlockProcess(ctx, wsb, tRoot, 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 block root `root` is ready in the database
+// for the blocroot `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
@@ -12,7 +12,6 @@ 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"
@@ -34,8 +33,8 @@ 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, avs das.AvailabilityStore) error
-	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityStore) error
+	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error
+	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock) error
 	HasBlock(ctx context.Context, root [32]byte) bool
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 	BlockBeingSynced([32]byte) bool
@@ -57,7 +56,7 @@ 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, avs das.AvailabilityStore) error {
+func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlock")
 	defer span.End()
 	// Return early if the block has been synced
@@ -73,10 +72,6 @@ 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 {
@@ -111,37 +106,21 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err := eg.Wait(); err != nil {
 		return err
 	}
-	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")
-		}
+	if err := s.isDataAvailable(ctx, blockRoot, blockCopy); err != nil {
+		return errors.Wrap(err, "could not validate blob data availability")
 	}
-	daWaitedTime := time.Since(daStartTime)
-
 	// 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")
 	}
-	args := &postBlockProcessConfig{
-		ctx:            ctx,
-		signed:         blockCopy,
-		blockRoot:      blockRoot,
-		postState:      postState,
-		isValidPayload: isValidPayload,
-	}
-	if err := s.postBlockProcess(args); err != nil {
+	if err := s.postBlockProcess(ctx, blockCopy, blockRoot, postState, isValidPayload); err != nil {
 		err := errors.Wrap(err, "could not process block")
 		tracing.AnnotateError(span, err)
 		return err
 	}
-	if coreTime.CurrentEpoch(postState) > currentEpoch && s.cfg.ForkChoiceStore.IsCanonical(blockRoot) {
+	if coreTime.CurrentEpoch(postState) > currentEpoch {
 		headSt, err := s.HeadState(ctx)
 		if err != nil {
 			return errors.Wrap(err, "could not get head state")
@@ -192,7 +171,7 @@ 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()), daWaitedTime); err != nil {
+	if err := logBlockSyncStatus(blockCopy.Block(), blockRoot, justified, finalized, receivedTime, uint64(s.genesisTime.Unix())); err != nil {
 		log.WithError(err).Error("Unable to log block sync status")
 	}
 	// Log payload data
@@ -204,8 +183,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		log.WithError(err).Error("Unable to log state transition data")
 	}

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

 	return nil
 }
@@ -213,7 +191,7 @@ 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, avs das.AvailabilityStore) error {
+func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlockBatch")
 	defer span.End()

@@ -221,7 +199,7 @@ 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, avs); err != nil {
+	if err := s.onBlockBatch(ctx, blocks); err != nil {
 		err := errors.Wrap(err, "could not process block in batch")
 		tracing.AnnotateError(span, err)
 		return err
@@ -280,6 +258,11 @@ func (s *Service) HasBlock(ctx context.Context, root [32]byte) bool {
 	return s.hasBlockInInitSyncOrDB(ctx, root)
 }

+// RecentBlockSlot returns block slot form fork choice store
+func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
+	return s.cfg.ForkChoiceStore.Slot(root)
+}
+
 // ReceiveAttesterSlashing receives an attester slashing and inserts it to forkchoice
 func (s *Service) ReceiveAttesterSlashing(ctx context.Context, slashing *ethpb.AttesterSlashing) {
 	s.cfg.ForkChoiceStore.Lock()
--- a/beacon-chain/blockchain/receive_block_test.go
+++ b/beacon-chain/blockchain/receive_block_test.go
@@ -7,8 +7,6 @@ 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"
@@ -132,9 +130,7 @@ func TestService_ReceiveBlock(t *testing.T) {
 			s, tr := minimalTestService(t,
 				WithFinalizedStateAtStartUp(genesis),
 				WithExitPool(voluntaryexits.NewPool()),
-				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
-				WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
-			)
+				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}))

 			beaconDB := tr.db
 			genesisBlockRoot := bytesutil.ToBytes32(nil)
@@ -147,7 +143,7 @@ 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, nil)
+			err = s.ReceiveBlock(ctx, wsb, root)
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
@@ -180,7 +176,7 @@ 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, nil))
+		require.NoError(t, s.ReceiveBlock(ctx, wsb, root))
 		wg.Done()
 	}()
 	wg.Wait()
@@ -244,7 +240,7 @@ 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}, &das.MockAvailabilityStore{})
+			err = s.ReceiveBlockBatch(ctx, []blocks.ROBlock{rwsb})
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -73,8 +73,7 @@ type config struct {
 	ChainStartFetcher       execution.ChainStartFetcher
 	BeaconDB                db.HeadAccessDatabase
 	DepositCache            cache.DepositCache
-	PayloadIDCache          *cache.PayloadIDCache
-	TrackedValidatorsCache  *cache.TrackedValidatorsCache
+	ProposerSlotIndexCache  *cache.ProposerPayloadIDsCache
 	AttPool                 attestations.Pool
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
@@ -168,7 +167,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 		checkpointStateCache: cache.NewCheckpointStateCache(),
 		initSyncBlocks:       make(map[[32]byte]interfaces.ReadOnlySignedBeaconBlock),
 		blobNotifiers:        bn,
-		cfg:                  &config{},
+		cfg:                  &config{ProposerSlotIndexCache: cache.NewProposerPayloadIDsCache()},
 		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),
-		WithPayloadIDCache(cache.NewPayloadIDCache()),
+		WithProposerIdsCache(cache.NewProposerPayloadIDsCache()),
 		WithClockSynchronizer(startup.NewClockSynchronizer()),
 	}

--- a/beacon-chain/blockchain/setup_test.go
+++ b/beacon-chain/blockchain/setup_test.go
@@ -6,7 +6,6 @@ import (
 	"testing"

 	"github.com/prysmaticlabs/prysm/v4/async/event"
-	"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"
@@ -57,7 +56,7 @@ func (mb *mockBroadcaster) BroadcastSyncCommitteeMessage(_ context.Context, _ ui
 	return nil
 }

-func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.BlobSidecar) error {
+func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.SignedBlobSidecar) error {
 	mb.broadcastCalled = true
 	return nil
 }
@@ -115,7 +114,6 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithAttestationService(req.attSrv),
 		WithBLSToExecPool(req.blsPool),
 		WithDepositCache(dc),
-		WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
 	}
 	// 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
@@ -17,7 +17,6 @@ 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
@@ -16,7 +16,6 @@ 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"
@@ -74,7 +73,6 @@ 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) {
@@ -209,7 +207,7 @@ 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, _ das.AvailabilityStore) error {
+func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBlock) error {
 	if s.State == nil {
 		return ErrNilState
 	}
@@ -239,7 +237,7 @@ 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, _ das.AvailabilityStore) error {
+func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, _ [32]byte) error {
 	if s.ReceiveBlockMockErr != nil {
 		return s.ReceiveBlockMockErr
 	}
@@ -321,7 +319,7 @@ 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
 }

@@ -401,12 +399,12 @@ 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")
 	}
@@ -414,7 +412,7 @@ func (*ChainService) VerifyLmdFfgConsistency(_ context.Context, a *ethpb.Attesta
 }

 // 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)),
@@ -423,7 +421,7 @@ 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
 }

@@ -487,7 +485,7 @@ func (s *ChainService) UpdateHead(ctx context.Context, slot primitives.Slot) {
 }

 // ReceiveAttesterSlashing mocks the same method in the chain service.
-func (*ChainService) ReceiveAttesterSlashing(context.Context, *ethpb.AttesterSlashing) {}
+func (s *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 {
@@ -600,12 +598,12 @@ func (s *ChainService) ProposerBoost() [32]byte {
 }

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

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

@@ -619,8 +617,3 @@ 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
@@ -1,27 +0,0 @@
-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
@@ -15,6 +15,7 @@ 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
@@ -2,6 +2,7 @@ package builder

 import (
 	"context"
+	"fmt"
 	"reflect"
 	"time"

@@ -10,6 +11,7 @@ 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"
@@ -25,7 +27,7 @@ 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) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (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)
@@ -88,7 +90,7 @@ 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) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlock")
 	defer span.End()
 	start := time.Now()
@@ -98,8 +100,11 @@ 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)
+	return s.c.SubmitBlindedBlock(ctx, b, blobs)
 }

 // 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)
+	_, _, err = s.SubmitBlindedBlock(context.Background(), nil, 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
@@ -45,7 +45,7 @@ func (s *MockBuilderService) Configured() bool {
 }

 // SubmitBlindedBlock for mocking.
-func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock, _ []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	switch b.Version() {
 	case version.Bellatrix:
 		w, err := blocks.WrappedExecutionPayload(s.Payload)
--- a/beacon-chain/cache/BUILD.bazel
+++ b/beacon-chain/cache/BUILD.bazel
@@ -25,7 +25,6 @@ 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 = [
@@ -34,7 +33,6 @@ 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",
@@ -80,7 +78,6 @@ 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",
@@ -93,7 +90,6 @@ 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
@@ -1,41 +1,171 @@
 package cache

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

-	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"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"
 )

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

-// AttestationCache stores cached results of AttestationData requests.
+	// 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.
 type AttestationCache struct {
-	a *AttestationConsensusData
-	sync.RWMutex
+	cache      *cache.FIFO
+	lock       sync.RWMutex
+	inProgress map[string]bool
 }

-// NewAttestationCache creates a new instance of AttestationCache.
+// NewAttestationCache initializes the map and underlying cache.
 func NewAttestationCache() *AttestationCache {
-	return &AttestationCache{}
-}
-
-// Get retrieves cached attestation data, recording a cache hit or miss. This method is lock free.
-func (c *AttestationCache) Get() *AttestationConsensusData {
-	return c.a
-}
-
-// 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")
+	return &AttestationCache{
+		cache:      cache.NewFIFO(wrapperToKey),
+		inProgress: make(map[string]bool),
 	}
-	c.a = a
+}
+
+// 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
+}
+
+// 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
+	}
+	if c.inProgress[s] {
+		return ErrAlreadyInProgress
+	}
+	c.inProgress[s] = true
 	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
@@ -1,53 +1,41 @@
 package cache_test

 import (
+	"context"
 	"testing"

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

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

-	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},
-		},
+	req := &ethpb.AttestationDataRequest{
+		CommitteeIndex: 0,
+		Slot:           1,
 	}

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

-	a = c.Get()
-	require.Equal(t, insert, a)
+	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/beacon-chain/cache/common.go
+++ b/beacon-chain/cache/common.go
@@ -1,9 +1,16 @@
 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/beacon-chain/cache/depositcache/deposits_cache.go
+++ b/beacon-chain/cache/depositcache/deposits_cache.go
@@ -70,7 +70,7 @@ func New() (*DepositCache, error) {
 // InsertDeposit into the database. If deposit or block number are nil
 // then this method does nothing.
 func (dc *DepositCache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blockNum uint64, index int64, depositRoot [32]byte) error {
-	_, span := trace.StartSpan(ctx, "DepositsCache.InsertDeposit")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertDeposit")
 	defer span.End()
 	if d == nil {
 		log.WithFields(logrus.Fields{
@@ -104,7 +104,7 @@ func (dc *DepositCache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blo

 // InsertDepositContainers inserts a set of deposit containers into our deposit cache.
 func (dc *DepositCache) InsertDepositContainers(ctx context.Context, ctrs []*ethpb.DepositContainer) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.InsertDepositContainers")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertDepositContainers")
 	defer span.End()
 	dc.depositsLock.Lock()
 	defer dc.depositsLock.Unlock()
@@ -124,7 +124,7 @@ func (dc *DepositCache) InsertDepositContainers(ctx context.Context, ctrs []*eth
 // InsertFinalizedDeposits inserts deposits up to eth1DepositIndex (inclusive) into the finalized deposits cache.
 func (dc *DepositCache) InsertFinalizedDeposits(ctx context.Context,
 	eth1DepositIndex int64, _ common.Hash, _ uint64) error {
-	_, span := trace.StartSpan(ctx, "DepositsCache.InsertFinalizedDeposits")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertFinalizedDeposits")
 	defer span.End()
 	dc.depositsLock.Lock()
 	defer dc.depositsLock.Unlock()
@@ -176,7 +176,7 @@ func (dc *DepositCache) InsertFinalizedDeposits(ctx context.Context,

 // AllDepositContainers returns all historical deposit containers.
 func (dc *DepositCache) AllDepositContainers(ctx context.Context) []*ethpb.DepositContainer {
-	_, span := trace.StartSpan(ctx, "DepositsCache.AllDepositContainers")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.AllDepositContainers")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -220,7 +220,7 @@ func (dc *DepositCache) allDeposits(untilBlk *big.Int) []*ethpb.Deposit {
 // DepositsNumberAndRootAtHeight returns number of deposits made up to blockheight and the
 // root that corresponds to the latest deposit at that blockheight.
 func (dc *DepositCache) DepositsNumberAndRootAtHeight(ctx context.Context, blockHeight *big.Int) (uint64, [32]byte) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.DepositsNumberAndRootAtHeight")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.DepositsNumberAndRootAtHeight")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -236,7 +236,7 @@ func (dc *DepositCache) DepositsNumberAndRootAtHeight(ctx context.Context, block
 // DepositByPubkey looks through historical deposits and finds one which contains
 // a certain public key within its deposit data.
 func (dc *DepositCache) DepositByPubkey(ctx context.Context, pubKey []byte) (*ethpb.Deposit, *big.Int) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.DepositByPubkey")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.DepositByPubkey")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -257,7 +257,7 @@ func (dc *DepositCache) DepositByPubkey(ctx context.Context, pubKey []byte) (*et

 // FinalizedDeposits returns the finalized deposits trie.
 func (dc *DepositCache) FinalizedDeposits(ctx context.Context) (cache.FinalizedDeposits, error) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.FinalizedDeposits")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.FinalizedDeposits")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -271,7 +271,7 @@ func (dc *DepositCache) FinalizedDeposits(ctx context.Context) (cache.FinalizedD
 // NonFinalizedDeposits returns the list of non-finalized deposits until the given block number (inclusive).
 // If no block is specified then this method returns all non-finalized deposits.
 func (dc *DepositCache) NonFinalizedDeposits(ctx context.Context, lastFinalizedIndex int64, untilBlk *big.Int) []*ethpb.Deposit {
-	_, span := trace.StartSpan(ctx, "DepositsCache.NonFinalizedDeposits")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.NonFinalizedDeposits")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -292,7 +292,7 @@ func (dc *DepositCache) NonFinalizedDeposits(ctx context.Context, lastFinalizedI

 // PruneProofs removes proofs from all deposits whose index is equal or less than untilDepositIndex.
 func (dc *DepositCache) PruneProofs(ctx context.Context, untilDepositIndex int64) error {
-	_, span := trace.StartSpan(ctx, "DepositsCache.PruneProofs")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.PruneProofs")
 	defer span.End()
 	dc.depositsLock.Lock()
 	defer dc.depositsLock.Unlock()
@@ -314,10 +314,7 @@ func (dc *DepositCache) PruneProofs(ctx context.Context, untilDepositIndex int64

 // Deposits returns the cached internal deposit tree.
 func (fd *FinalizedDeposits) Deposits() cache.MerkleTree {
-	if fd.deposits != nil {
-		return fd.deposits
-	}
-	return nil
+	return fd.deposits
 }

 // MerkleTrieIndex represents the last finalized index in
--- a/beacon-chain/cache/depositcache/pending_deposits.go
+++ b/beacon-chain/cache/depositcache/pending_deposits.go
@@ -29,7 +29,7 @@ type PendingDepositsFetcher interface {
 // InsertPendingDeposit into the database. If deposit or block number are nil
 // then this method does nothing.
 func (dc *DepositCache) InsertPendingDeposit(ctx context.Context, d *ethpb.Deposit, blockNum uint64, index int64, depositRoot [32]byte) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.InsertPendingDeposit")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.InsertPendingDeposit")
 	defer span.End()
 	if d == nil {
 		log.WithFields(logrus.Fields{
@@ -66,7 +66,7 @@ func (dc *DepositCache) PendingDeposits(ctx context.Context, untilBlk *big.Int)
 // PendingContainers returns a list of deposit containers until the given block number
 // (inclusive).
 func (dc *DepositCache) PendingContainers(ctx context.Context, untilBlk *big.Int) []*ethpb.DepositContainer {
-	_, span := trace.StartSpan(ctx, "DepositsCache.PendingDeposits")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.PendingDeposits")
 	defer span.End()
 	dc.depositsLock.RLock()
 	defer dc.depositsLock.RUnlock()
@@ -90,7 +90,7 @@ func (dc *DepositCache) PendingContainers(ctx context.Context, untilBlk *big.Int
 // RemovePendingDeposit from the database. The deposit is indexed by the
 // Index. This method does nothing if deposit ptr is nil.
 func (dc *DepositCache) RemovePendingDeposit(ctx context.Context, d *ethpb.Deposit) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.RemovePendingDeposit")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.RemovePendingDeposit")
 	defer span.End()

 	if d == nil {
@@ -128,7 +128,7 @@ func (dc *DepositCache) RemovePendingDeposit(ctx context.Context, d *ethpb.Depos

 // PrunePendingDeposits removes any deposit which is older than the given deposit merkle tree index.
 func (dc *DepositCache) PrunePendingDeposits(ctx context.Context, merkleTreeIndex int64) {
-	_, span := trace.StartSpan(ctx, "DepositsCache.PrunePendingDeposits")
+	ctx, span := trace.StartSpan(ctx, "DepositsCache.PrunePendingDeposits")
 	defer span.End()

 	if merkleTreeIndex == 0 {
--- a/beacon-chain/cache/depositsnapshot/deposit_fetcher.go
+++ b/beacon-chain/cache/depositsnapshot/deposit_fetcher.go
@@ -76,7 +76,7 @@ func (c *Cache) allDeposits(untilBlk *big.Int) []*ethpb.Deposit {

 // AllDepositContainers returns all historical deposit containers.
 func (c *Cache) AllDepositContainers(ctx context.Context) []*ethpb.DepositContainer {
-	_, span := trace.StartSpan(ctx, "Cache.AllDepositContainers")
+	ctx, span := trace.StartSpan(ctx, "Cache.AllDepositContainers")
 	defer span.End()
 	c.depositsLock.RLock()
 	defer c.depositsLock.RUnlock()
@@ -101,7 +101,7 @@ func (c *Cache) AllDepositContainers(ctx context.Context) []*ethpb.DepositContai
 // DepositByPubkey looks through historical deposits and finds one which contains
 // a certain public key within its deposit data.
 func (c *Cache) DepositByPubkey(ctx context.Context, pubKey []byte) (*ethpb.Deposit, *big.Int) {
-	_, span := trace.StartSpan(ctx, "Cache.DepositByPubkey")
+	ctx, span := trace.StartSpan(ctx, "Cache.DepositByPubkey")
 	defer span.End()
 	c.depositsLock.RLock()
 	defer c.depositsLock.RUnlock()
@@ -123,7 +123,7 @@ func (c *Cache) DepositByPubkey(ctx context.Context, pubKey []byte) (*ethpb.Depo
 // DepositsNumberAndRootAtHeight returns number of deposits made up to blockheight and the
 // root that corresponds to the latest deposit at that blockheight.
 func (c *Cache) DepositsNumberAndRootAtHeight(ctx context.Context, blockHeight *big.Int) (uint64, [32]byte) {
-	_, span := trace.StartSpan(ctx, "Cache.DepositsNumberAndRootAtHeight")
+	ctx, span := trace.StartSpan(ctx, "Cache.DepositsNumberAndRootAtHeight")
 	defer span.End()
 	c.depositsLock.RLock()
 	defer c.depositsLock.RUnlock()
@@ -141,7 +141,7 @@ func (c *Cache) DepositsNumberAndRootAtHeight(ctx context.Context, blockHeight *

 // FinalizedDeposits returns the finalized deposits trie.
 func (c *Cache) FinalizedDeposits(ctx context.Context) (cache.FinalizedDeposits, error) {
-	_, span := trace.StartSpan(ctx, "Cache.FinalizedDeposits")
+	ctx, span := trace.StartSpan(ctx, "Cache.FinalizedDeposits")
 	defer span.End()
 	c.depositsLock.RLock()
 	defer c.depositsLock.RUnlock()
@@ -159,7 +159,7 @@ func (c *Cache) FinalizedDeposits(ctx context.Context) (cache.FinalizedDeposits,
 // NonFinalizedDeposits returns the list of non-finalized deposits until the given block number (inclusive).
 // If no block is specified then this method returns all non-finalized deposits.
 func (c *Cache) NonFinalizedDeposits(ctx context.Context, lastFinalizedIndex int64, untilBlk *big.Int) []*ethpb.Deposit {
-	_, span := trace.StartSpan(ctx, "Cache.NonFinalizedDeposits")
+	ctx, span := trace.StartSpan(ctx, "Cache.NonFinalizedDeposits")
 	defer span.End()
 	c.depositsLock.RLock()
 	defer c.depositsLock.RUnlock()
@@ -180,7 +180,7 @@ func (c *Cache) NonFinalizedDeposits(ctx context.Context, lastFinalizedIndex int

 // PruneProofs removes proofs from all deposits whose index is equal or less than untilDepositIndex.
 func (c *Cache) PruneProofs(ctx context.Context, untilDepositIndex int64) error {
-	_, span := trace.StartSpan(ctx, "Cache.PruneProofs")
+	ctx, span := trace.StartSpan(ctx, "Cache.PruneProofs")
 	defer span.End()
 	c.depositsLock.Lock()
 	defer c.depositsLock.Unlock()
@@ -202,7 +202,7 @@ func (c *Cache) PruneProofs(ctx context.Context, untilDepositIndex int64) error

 // PrunePendingDeposits removes any deposit which is older than the given deposit merkle tree index.
 func (c *Cache) PrunePendingDeposits(ctx context.Context, merkleTreeIndex int64) {
-	_, span := trace.StartSpan(ctx, "Cache.PrunePendingDeposits")
+	ctx, span := trace.StartSpan(ctx, "Cache.PrunePendingDeposits")
 	defer span.End()

 	if merkleTreeIndex == 0 {
@@ -227,7 +227,7 @@ func (c *Cache) PrunePendingDeposits(ctx context.Context, merkleTreeIndex int64)
 // InsertPendingDeposit into the database. If deposit or block number are nil
 // then this method does nothing.
 func (c *Cache) InsertPendingDeposit(ctx context.Context, d *ethpb.Deposit, blockNum uint64, index int64, depositRoot [32]byte) {
-	_, span := trace.StartSpan(ctx, "Cache.InsertPendingDeposit")
+	ctx, span := trace.StartSpan(ctx, "Cache.InsertPendingDeposit")
 	defer span.End()
 	if d == nil {
 		log.WithFields(logrus.Fields{
@@ -282,7 +282,7 @@ func (c *Cache) PendingDeposits(ctx context.Context, untilBlk *big.Int) []*ethpb
 // PendingContainers returns a list of deposit containers until the given block number
 // (inclusive).
 func (c *Cache) PendingContainers(ctx context.Context, untilBlk *big.Int) []*ethpb.DepositContainer {
-	_, span := trace.StartSpan(ctx, "Cache.PendingContainers")
+	ctx, span := trace.StartSpan(ctx, "Cache.PendingContainers")
 	defer span.End()
 	c.depositsLock.RLock()
 	defer c.depositsLock.RUnlock()
--- a/beacon-chain/cache/depositsnapshot/deposit_inserter.go
+++ b/beacon-chain/cache/depositsnapshot/deposit_inserter.go
@@ -28,9 +28,6 @@ var (
 func (c *Cache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blockNum uint64, index int64, depositRoot [32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "Cache.InsertDeposit")
 	defer span.End()
-	if ctx.Err() != nil {
-		return ctx.Err()
-	}
 	if d == nil {
 		log.WithFields(logrus.Fields{
 			"block":        blockNum,
@@ -63,7 +60,7 @@ func (c *Cache) InsertDeposit(ctx context.Context, d *ethpb.Deposit, blockNum ui

 // InsertDepositContainers inserts a set of deposit containers into our deposit cache.
 func (c *Cache) InsertDepositContainers(ctx context.Context, ctrs []*ethpb.DepositContainer) {
-	_, span := trace.StartSpan(ctx, "Cache.InsertDepositContainers")
+	ctx, span := trace.StartSpan(ctx, "Cache.InsertDepositContainers")
 	defer span.End()
 	c.depositsLock.Lock()
 	defer c.depositsLock.Unlock()
@@ -92,10 +89,6 @@ func (c *Cache) InsertFinalizedDeposits(ctx context.Context, eth1DepositIndex in
 	c.depositsLock.Lock()
 	defer c.depositsLock.Unlock()

-	if ctx.Err() != nil {
-		return ctx.Err()
-	}
-
 	depositTrie := c.finalizedDeposits.depositTree
 	insertIndex := int(c.finalizedDeposits.MerkleTrieIndex() + 1)

--- a/beacon-chain/cache/error.go
+++ b/beacon-chain/cache/error.go
@@ -14,9 +14,4 @@ var (
 	errNotSyncCommitteeIndexPosition = errors.New("not syncCommitteeIndexPosition struct")
 	// ErrNotFoundRegistration when validator registration does not exist in cache.
 	ErrNotFoundRegistration = errors.Wrap(ErrNotFound, "no validator registered")
-
-	// 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.
-	ErrAlreadyInProgress = errors.New("already in progress")
 )
--- a/beacon-chain/cache/payload_id.go
+++ b/beacon-chain/cache/payload_id.go
@@ -1,63 +1,94 @@
 package cache

 import (
+	"bytes"
 	"sync"

+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 )

-// RootToPayloadIDMap is a map with keys the head root and values the
-// corresponding PayloadID
-type RootToPayloadIDMap map[[32]byte]primitives.PayloadID
+const keyLength = 40
+const vIdLength = 8
+const pIdLength = 8
+const vpIdsLength = vIdLength + pIdLength

-// PayloadIDCache is a cache that keeps track of the prepared payload ID for the
-// given slot and with the given head root.
-type PayloadIDCache struct {
-	slotToPayloadID map[primitives.Slot]RootToPayloadIDMap
-	sync.Mutex
+// ProposerPayloadIDsCache is a cache of proposer payload IDs.
+// The key is the concatenation of the slot and the block root.
+// The value is the concatenation of the proposer and payload IDs, 8 bytes each.
+type ProposerPayloadIDsCache struct {
+	slotToProposerAndPayloadIDs map[[keyLength]byte][vpIdsLength]byte
+	sync.RWMutex
 }

-// NewPayloadIDCache returns a new payload ID cache
-func NewPayloadIDCache() *PayloadIDCache {
-	return &PayloadIDCache{slotToPayloadID: make(map[primitives.Slot]RootToPayloadIDMap)}
+// NewProposerPayloadIDsCache creates a new proposer payload IDs cache.
+func NewProposerPayloadIDsCache() *ProposerPayloadIDsCache {
+	return &ProposerPayloadIDsCache{
+		slotToProposerAndPayloadIDs: make(map[[keyLength]byte][vpIdsLength]byte),
+	}
 }

-// PayloadID returns the payload ID for the given slot and parent block root
-func (p *PayloadIDCache) PayloadID(slot primitives.Slot, root [32]byte) (primitives.PayloadID, bool) {
-	p.Lock()
-	defer p.Unlock()
-	inner, ok := p.slotToPayloadID[slot]
+// GetProposerPayloadIDs returns the proposer and payload IDs for the given slot and head root to build the block.
+func (f *ProposerPayloadIDsCache) GetProposerPayloadIDs(
+	slot primitives.Slot,
+	r [fieldparams.RootLength]byte,
+) (primitives.ValidatorIndex, [pIdLength]byte, bool) {
+	f.RLock()
+	defer f.RUnlock()
+	ids, ok := f.slotToProposerAndPayloadIDs[idKey(slot, r)]
 	if !ok {
-		return primitives.PayloadID{}, false
+		return 0, [pIdLength]byte{}, false
 	}
-	pid, ok := inner[root]
-	if !ok {
-		return primitives.PayloadID{}, false
-	}
-	return pid, true
+	vId := ids[:vIdLength]
+
+	b := ids[vIdLength:]
+	var pId [pIdLength]byte
+	copy(pId[:], b)
+
+	return primitives.ValidatorIndex(bytesutil.BytesToUint64BigEndian(vId)), pId, true
 }

-// SetPayloadID updates the payload ID for the given slot and head root
-// it also prunes older entries in the cache
-func (p *PayloadIDCache) Set(slot primitives.Slot, root [32]byte, pid primitives.PayloadID) {
-	p.Lock()
-	defer p.Unlock()
-	if slot > 1 {
-		p.prune(slot - 2)
+// SetProposerAndPayloadIDs sets the proposer and payload IDs for the given slot and head root to build block.
+func (f *ProposerPayloadIDsCache) SetProposerAndPayloadIDs(
+	slot primitives.Slot,
+	vId primitives.ValidatorIndex,
+	pId [pIdLength]byte,
+	r [fieldparams.RootLength]byte,
+) {
+	f.Lock()
+	defer f.Unlock()
+	var vIdBytes [vIdLength]byte
+	copy(vIdBytes[:], bytesutil.Uint64ToBytesBigEndian(uint64(vId)))
+
+	var bs [vpIdsLength]byte
+	copy(bs[:], append(vIdBytes[:], pId[:]...))
+
+	k := idKey(slot, r)
+	ids, ok := f.slotToProposerAndPayloadIDs[k]
+	// Ok to overwrite if the slot is already set but the cached payload ID is not set.
+	// This combats the re-org case where payload assignment could change at the start of the epoch.
+	var byte8 [vIdLength]byte
+	if !ok || (ok && bytes.Equal(ids[vIdLength:], byte8[:])) {
+		f.slotToProposerAndPayloadIDs[k] = bs
 	}
-	inner, ok := p.slotToPayloadID[slot]
-	if !ok {
-		inner = make(RootToPayloadIDMap)
-		p.slotToPayloadID[slot] = inner
-	}
-	inner[root] = pid
 }

-// Prune prunes old payload IDs. Requires a Lock in the cache
-func (p *PayloadIDCache) prune(slot primitives.Slot) {
-	for key := range p.slotToPayloadID {
-		if key < slot {
-			delete(p.slotToPayloadID, key)
+// PrunePayloadIDs removes the payload ID entries older than input slot.
+func (f *ProposerPayloadIDsCache) PrunePayloadIDs(slot primitives.Slot) {
+	f.Lock()
+	defer f.Unlock()
+
+	for k := range f.slotToProposerAndPayloadIDs {
+		s := primitives.Slot(bytesutil.BytesToUint64BigEndian(k[:8]))
+		if slot > s {
+			delete(f.slotToProposerAndPayloadIDs, k)
 		}
 	}
 }
+
+func idKey(slot primitives.Slot, r [fieldparams.RootLength]byte) [keyLength]byte {
+	var k [keyLength]byte
+	copy(k[:], append(bytesutil.Uint64ToBytesBigEndian(uint64(slot)), r[:]...))
+	return k
+}
--- a/beacon-chain/cache/payload_id_test.go
+++ b/beacon-chain/cache/payload_id_test.go
@@ -8,54 +8,65 @@ import (
 )

 func TestValidatorPayloadIDsCache_GetAndSaveValidatorPayloadIDs(t *testing.T) {
-	cache := NewPayloadIDCache()
+	cache := NewProposerPayloadIDsCache()
 	var r [32]byte
-	p, ok := cache.PayloadID(0, r)
+	i, p, ok := cache.GetProposerPayloadIDs(0, r)
 	require.Equal(t, false, ok)
-	require.Equal(t, primitives.PayloadID{}, p)
+	require.Equal(t, primitives.ValidatorIndex(0), i)
+	require.Equal(t, [pIdLength]byte{}, p)

 	slot := primitives.Slot(1234)
-	pid := primitives.PayloadID{1, 2, 3, 3, 7, 8, 7, 8}
+	vid := primitives.ValidatorIndex(34234324)
+	pid := [8]byte{1, 2, 3, 3, 7, 8, 7, 8}
 	r = [32]byte{1, 2, 3}
-	cache.Set(slot, r, pid)
-	p, ok = cache.PayloadID(slot, r)
+	cache.SetProposerAndPayloadIDs(slot, vid, pid, r)
+	i, p, ok = cache.GetProposerPayloadIDs(slot, r)
 	require.Equal(t, true, ok)
+	require.Equal(t, vid, i)
 	require.Equal(t, pid, p)

 	slot = primitives.Slot(9456456)
+	vid = primitives.ValidatorIndex(6786745)
 	r = [32]byte{4, 5, 6}
-	cache.Set(slot, r, primitives.PayloadID{})
-	p, ok = cache.PayloadID(slot, r)
+	cache.SetProposerAndPayloadIDs(slot, vid, [pIdLength]byte{}, r)
+	i, p, ok = cache.GetProposerPayloadIDs(slot, r)
 	require.Equal(t, true, ok)
-	require.Equal(t, primitives.PayloadID{}, p)
+	require.Equal(t, vid, i)
+	require.Equal(t, [pIdLength]byte{}, p)

 	// reset cache without pid
 	slot = primitives.Slot(9456456)
+	vid = primitives.ValidatorIndex(11111)
 	r = [32]byte{7, 8, 9}
 	pid = [8]byte{3, 2, 3, 33, 72, 8, 7, 8}
-	cache.Set(slot, r, pid)
-	p, ok = cache.PayloadID(slot, r)
+	cache.SetProposerAndPayloadIDs(slot, vid, pid, r)
+	i, p, ok = cache.GetProposerPayloadIDs(slot, r)
 	require.Equal(t, true, ok)
+	require.Equal(t, vid, i)
 	require.Equal(t, pid, p)

 	// Forked chain
 	r = [32]byte{1, 2, 3}
-	p, ok = cache.PayloadID(slot, r)
+	i, p, ok = cache.GetProposerPayloadIDs(slot, r)
 	require.Equal(t, false, ok)
-	require.Equal(t, primitives.PayloadID{}, p)
+	require.Equal(t, primitives.ValidatorIndex(0), i)
+	require.Equal(t, [pIdLength]byte{}, p)

-	// existing pid - change the cache
+	// existing pid - no change in cache
 	slot = primitives.Slot(9456456)
+	vid = primitives.ValidatorIndex(11111)
 	r = [32]byte{7, 8, 9}
-	newPid := primitives.PayloadID{1, 2, 3, 33, 72, 8, 7, 1}
-	cache.Set(slot, r, newPid)
-	p, ok = cache.PayloadID(slot, r)
+	newPid := [8]byte{1, 2, 3, 33, 72, 8, 7, 1}
+	cache.SetProposerAndPayloadIDs(slot, vid, newPid, r)
+	i, p, ok = cache.GetProposerPayloadIDs(slot, r)
 	require.Equal(t, true, ok)
-	require.Equal(t, newPid, p)
+	require.Equal(t, vid, i)
+	require.Equal(t, pid, p)

 	// remove cache entry
-	cache.prune(slot + 1)
-	p, ok = cache.PayloadID(slot, r)
+	cache.PrunePayloadIDs(slot + 1)
+	i, p, ok = cache.GetProposerPayloadIDs(slot, r)
 	require.Equal(t, false, ok)
-	require.Equal(t, primitives.PayloadID{}, p)
+	require.Equal(t, primitives.ValidatorIndex(0), i)
+	require.Equal(t, [pIdLength]byte{}, p)
 }
--- a/beacon-chain/cache/proposer_indices.go
+++ b/beacon-chain/cache/proposer_indices.go
@@ -7,12 +7,15 @@ import (

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

 var (
+	// maxProposerIndicesCacheSize defines the max number of proposer indices on per block root basis can cache.
+	// Due to reorgs and long finality, it's good to keep the old cache around for quickly switch over.
+	maxProposerIndicesCacheSize = uint64(8)
+
 	// ProposerIndicesCacheMiss tracks the number of proposerIndices requests that aren't present in the cache.
 	ProposerIndicesCacheMiss = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "proposer_indices_cache_miss",
@@ -25,97 +28,85 @@ var (
 	})
 )

-// ProposerIndicesCache keeps track of the proposer indices in the next two
-// epochs. It is keyed by the state root of the last epoch before. That is, for
-// blocks during epoch 2, for example slot 65, it will be keyed by the state
-// root of slot 63 (last slot in epoch 1).
-// The cache keeps two sets of indices computed, the "safe" set is computed
-// right before the epoch transition into the current epoch. For example for
-// epoch 2 we will compute this list after importing block 63. The "unsafe"
-// version is computed an epoch in advance, for example for epoch 3, it will be
-// computed after importing block 63.
-//
-// The cache also keeps a map from checkpoints to state roots so that one is
-// able to access the proposer indices list from a checkpoint instead. The
-// checkpoint is the checkpoint for the epoch previous to the requested
-// proposer indices. That is, for a slot in epoch 2 (eg. 65), the checkpoint
-// root would be for slot 32 if present.
+// ProposerIndicesCache is a struct with 1 queue for looking up proposer indices by root.
 type ProposerIndicesCache struct {
-	sync.Mutex
-	indices map[primitives.Epoch]map[[32]byte][fieldparams.SlotsPerEpoch]primitives.ValidatorIndex
-	rootMap map[forkchoicetypes.Checkpoint][32]byte // A map from checkpoint root to state root
+	proposerIndicesCache *cache.FIFO
+	lock                 sync.RWMutex
 }

-// NewProposerIndicesCache returns a newly created cache
-func NewProposerIndicesCache() *ProposerIndicesCache {
-	return &ProposerIndicesCache{
-		indices: make(map[primitives.Epoch]map[[32]byte][fieldparams.SlotsPerEpoch]primitives.ValidatorIndex),
-		rootMap: make(map[forkchoicetypes.Checkpoint][32]byte),
-	}
-}
-
-// ProposerIndices returns the proposer indices (safe) for the given root
-func (p *ProposerIndicesCache) ProposerIndices(epoch primitives.Epoch, root [32]byte) ([fieldparams.SlotsPerEpoch]primitives.ValidatorIndex, bool) {
-	p.Lock()
-	defer p.Unlock()
-	inner, ok := p.indices[epoch]
+// proposerIndicesKeyFn takes the block root as the key to retrieve proposer indices in a given epoch.
+func proposerIndicesKeyFn(obj interface{}) (string, error) {
+	info, ok := obj.(*ProposerIndices)
 	if !ok {
-		ProposerIndicesCacheMiss.Inc()
-		return [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}, false
+		return "", ErrNotProposerIndices
 	}
-	indices, exists := inner[root]
+
+	return key(info.BlockRoot), nil
+}
+
+// NewProposerIndicesCache creates a new proposer indices cache for storing/accessing proposer index assignments of an epoch.
+func NewProposerIndicesCache() *ProposerIndicesCache {
+	c := &ProposerIndicesCache{}
+	c.Clear()
+	return c
+}
+
+// Clear resets the ProposerIndicesCache to its initial state
+func (c *ProposerIndicesCache) Clear() {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.proposerIndicesCache = cache.NewFIFO(proposerIndicesKeyFn)
+}
+
+// AddProposerIndices adds ProposerIndices object to the cache.
+// This method also trims the least recently list if the cache size has ready the max cache size limit.
+func (c *ProposerIndicesCache) AddProposerIndices(p *ProposerIndices) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if err := c.proposerIndicesCache.AddIfNotPresent(p); err != nil {
+		return err
+	}
+	trim(c.proposerIndicesCache, maxProposerIndicesCacheSize)
+	return nil
+}
+
+// HasProposerIndices returns the proposer indices of a block root seed.
+func (c *ProposerIndicesCache) HasProposerIndices(r [32]byte) (bool, error) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	_, exists, err := c.proposerIndicesCache.GetByKey(key(r))
+	if err != nil {
+		return false, err
+	}
+	return exists, nil
+}
+
+// ProposerIndices returns the proposer indices of a block root seed.
+func (c *ProposerIndicesCache) ProposerIndices(r [32]byte) ([]primitives.ValidatorIndex, error) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	obj, exists, err := c.proposerIndicesCache.GetByKey(key(r))
+	if err != nil {
+		return nil, err
+	}
+
 	if exists {
 		ProposerIndicesCacheHit.Inc()
 	} else {
 		ProposerIndicesCacheMiss.Inc()
+		return nil, nil
 	}
-	return indices, exists
-}

-// Prune resets the ProposerIndicesCache to its initial state
-func (p *ProposerIndicesCache) Prune(epoch primitives.Epoch) {
-	p.Lock()
-	defer p.Unlock()
-	for key := range p.indices {
-		if key < epoch {
-			delete(p.indices, key)
-		}
-	}
-	for key := range p.rootMap {
-		if key.Epoch+1 < epoch {
-			delete(p.rootMap, key)
-		}
-	}
-}
-
-// Set sets the proposer indices for the given root as key
-func (p *ProposerIndicesCache) Set(epoch primitives.Epoch, root [32]byte, indices [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex) {
-	p.Lock()
-	defer p.Unlock()
-
-	inner, ok := p.indices[epoch]
+	item, ok := obj.(*ProposerIndices)
 	if !ok {
-		inner = make(map[[32]byte][fieldparams.SlotsPerEpoch]primitives.ValidatorIndex)
-		p.indices[epoch] = inner
+		return nil, ErrNotProposerIndices
 	}
-	inner[root] = indices
+
+	return item.ProposerIndices, nil
 }

-// SetCheckpoint updates the map from checkpoints to state roots
-func (p *ProposerIndicesCache) SetCheckpoint(c forkchoicetypes.Checkpoint, root [32]byte) {
-	p.Lock()
-	defer p.Unlock()
-	p.rootMap[c] = root
-}
-
-// IndicesFromCheckpoint returns the proposer indices from a checkpoint rather than the state root
-func (p *ProposerIndicesCache) IndicesFromCheckpoint(c forkchoicetypes.Checkpoint) ([fieldparams.SlotsPerEpoch]primitives.ValidatorIndex, bool) {
-	p.Lock()
-	emptyIndices := [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}
-	root, ok := p.rootMap[c]
-	p.Unlock()
-	if !ok {
-		return emptyIndices, ok
-	}
-	return p.ProposerIndices(c.Epoch+1, root)
+// Len returns the number of keys in the underlying cache.
+func (c *ProposerIndicesCache) Len() int {
+	return len(c.proposerIndicesCache.ListKeys())
 }
--- a/beacon-chain/cache/proposer_indices_disabled.go
+++ b/beacon-chain/cache/proposer_indices_disabled.go
@@ -3,26 +3,7 @@
 // This file is used in fuzzer builds to bypass proposer indices caches.
 package cache

-import (
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
-	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
-)
-
-var (
-	// ProposerIndicesCacheMiss tracks the number of proposerIndices requests that aren't present in the cache.
-	ProposerIndicesCacheMiss = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "proposer_indices_cache_miss",
-		Help: "The number of proposer indices requests that aren't present in the cache.",
-	})
-	// ProposerIndicesCacheHit tracks the number of proposerIndices requests that are in the cache.
-	ProposerIndicesCacheHit = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "proposer_indices_cache_hit",
-		Help: "The number of proposer indices requests that are present in the cache.",
-	})
-)
+import "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"

 // FakeProposerIndicesCache is a struct with 1 queue for looking up proposer indices by root.
 type FakeProposerIndicesCache struct {
@@ -33,31 +14,26 @@ func NewProposerIndicesCache() *FakeProposerIndicesCache {
 	return &FakeProposerIndicesCache{}
 }

-// ProposerIndices is a stub.
-func (c *FakeProposerIndicesCache) ProposerIndices(_ primitives.Epoch, _ [32]byte) ([fieldparams.SlotsPerEpoch]primitives.ValidatorIndex, bool) {
-	return [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}, false
+// AddProposerIndices adds ProposerIndices object to the cache.
+// This method also trims the least recently list if the cache size has ready the max cache size limit.
+func (c *FakeProposerIndicesCache) AddProposerIndices(p *ProposerIndices) error {
+	return nil
 }

-// UnsafeProposerIndices is a stub.
-func (c *FakeProposerIndicesCache) UnsafeProposerIndices(_ primitives.Epoch, _ [32]byte) ([fieldparams.SlotsPerEpoch]primitives.ValidatorIndex, bool) {
-	return [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}, false
+// ProposerIndices returns the proposer indices of a block root seed.
+func (c *FakeProposerIndicesCache) ProposerIndices(r [32]byte) ([]primitives.ValidatorIndex, error) {
+	return nil, nil
 }

-// Prune is a stub.
-func (p *FakeProposerIndicesCache) Prune(epoch primitives.Epoch) {}
-
-// Set is a stub.
-func (p *FakeProposerIndicesCache) Set(epoch primitives.Epoch, root [32]byte, indices [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex) {
+// HasProposerIndices returns the proposer indices of a block root seed.
+func (c *FakeProposerIndicesCache) HasProposerIndices(r [32]byte) (bool, error) {
+	return false, nil
 }

-// SetUnsafe is a stub.
-func (p *FakeProposerIndicesCache) SetUnsafe(epoch primitives.Epoch, root [32]byte, indices [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex) {
+func (c *FakeProposerIndicesCache) Len() int {
+	return 0
 }

-// SetCheckpoint is a stub.
-func (p *FakeProposerIndicesCache) SetCheckpoint(c forkchoicetypes.Checkpoint, root [32]byte) {}
-
-// IndicesFromCheckpoint is a stub.
-func (p *FakeProposerIndicesCache) IndicesFromCheckpoint(_ forkchoicetypes.Checkpoint) ([fieldparams.SlotsPerEpoch]primitives.ValidatorIndex, bool) {
-	return [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}, false
+// Clear is a stub.
+func (c *FakeProposerIndicesCache) Clear() {
 }
--- a/beacon-chain/cache/proposer_indices_test.go
+++ b/beacon-chain/cache/proposer_indices_test.go
@@ -3,104 +3,72 @@
 package cache

 import (
+	"strconv"
 	"testing"

-	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
-	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/testing/assert"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

-func TestProposerCache_Set(t *testing.T) {
+func TestProposerKeyFn_OK(t *testing.T) {
+	item := &ProposerIndices{
+		BlockRoot:       [32]byte{'A'},
+		ProposerIndices: []primitives.ValidatorIndex{1, 2, 3, 4, 5},
+	}
+
+	k, err := proposerIndicesKeyFn(item)
+	require.NoError(t, err)
+	assert.Equal(t, key(item.BlockRoot), k)
+}
+
+func TestProposerKeyFn_InvalidObj(t *testing.T) {
+	_, err := proposerIndicesKeyFn("bad")
+	assert.Equal(t, ErrNotProposerIndices, err)
+}
+
+func TestProposerCache_AddProposerIndicesList(t *testing.T) {
 	cache := NewProposerIndicesCache()
 	bRoot := [32]byte{'A'}
-	indices, ok := cache.ProposerIndices(0, bRoot)
-	require.Equal(t, false, ok)
-	emptyIndices := [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}
-	require.Equal(t, indices, emptyIndices, "Expected committee count not to exist in empty cache")
-	emptyIndices[0] = 1
-	cache.Set(0, bRoot, emptyIndices)
-
-	received, ok := cache.ProposerIndices(0, bRoot)
-	require.Equal(t, true, ok)
-	require.Equal(t, received, emptyIndices)
-
-	newRoot := [32]byte{'B'}
-	copy(emptyIndices[3:], []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6})
-	cache.Set(0, newRoot, emptyIndices)
-
-	received, ok = cache.ProposerIndices(0, newRoot)
-	require.Equal(t, true, ok)
-	require.Equal(t, emptyIndices, received)
-}
-
-func TestProposerCache_CheckpointAndPrune(t *testing.T) {
-	cache := NewProposerIndicesCache()
-	indices := [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}
-	root := [32]byte{'a'}
-	cpRoot := [32]byte{'b'}
-	copy(indices[3:], []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6})
-	for i := 1; i < 10; i++ {
-		cache.Set(primitives.Epoch(i), root, indices)
-		cache.SetCheckpoint(forkchoicetypes.Checkpoint{Epoch: primitives.Epoch(i - 1), Root: cpRoot}, root)
+	indices, err := cache.ProposerIndices(bRoot)
+	require.NoError(t, err)
+	if indices != nil {
+		t.Error("Expected committee count not to exist in empty cache")
 	}
-	received, ok := cache.ProposerIndices(1, root)
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
+	has, err := cache.HasProposerIndices(bRoot)
+	require.NoError(t, err)
+	assert.Equal(t, false, has)
+	require.NoError(t, cache.AddProposerIndices(&ProposerIndices{
+		ProposerIndices: indices,
+		BlockRoot:       bRoot,
+	}))

-	received, ok = cache.ProposerIndices(4, root)
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
+	received, err := cache.ProposerIndices(bRoot)
+	require.NoError(t, err)
+	assert.DeepEqual(t, received, indices)
+	has, err = cache.HasProposerIndices(bRoot)
+	require.NoError(t, err)
+	assert.Equal(t, true, has)

-	received, ok = cache.ProposerIndices(9, root)
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
+	item := &ProposerIndices{BlockRoot: [32]byte{'B'}, ProposerIndices: []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6}}
+	require.NoError(t, cache.AddProposerIndices(item))

-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 0, Root: cpRoot})
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 3, Root: cpRoot})
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 4, Root: cpRoot})
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 8, Root: cpRoot})
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
-
-	cache.Prune(5)
-
-	emptyIndices := [fieldparams.SlotsPerEpoch]primitives.ValidatorIndex{}
-	received, ok = cache.ProposerIndices(1, root)
-	require.Equal(t, false, ok)
-	require.Equal(t, emptyIndices, received)
-
-	received, ok = cache.ProposerIndices(4, root)
-	require.Equal(t, false, ok)
-	require.Equal(t, emptyIndices, received)
-
-	received, ok = cache.ProposerIndices(9, root)
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 0, Root: cpRoot})
-	require.Equal(t, false, ok)
-	require.Equal(t, emptyIndices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 3, Root: cpRoot})
-	require.Equal(t, false, ok)
-	require.Equal(t, emptyIndices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 4, Root: cpRoot})
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
-
-	received, ok = cache.IndicesFromCheckpoint(forkchoicetypes.Checkpoint{Epoch: 8, Root: cpRoot})
-	require.Equal(t, true, ok)
-	require.Equal(t, indices, received)
+	received, err = cache.ProposerIndices(item.BlockRoot)
+	require.NoError(t, err)
+	assert.DeepEqual(t, item.ProposerIndices, received)
+	has, err = cache.HasProposerIndices(bRoot)
+	require.NoError(t, err)
+	assert.Equal(t, true, has)

 }
+
+func TestProposerCache_CanRotate(t *testing.T) {
+	cache := NewProposerIndicesCache()
+	for i := 0; i < int(maxProposerIndicesCacheSize)+1; i++ {
+		s := []byte(strconv.Itoa(i))
+		item := &ProposerIndices{BlockRoot: bytesutil.ToBytes32(s)}
+		require.NoError(t, cache.AddProposerIndices(item))
+	}
+	assert.Equal(t, int(maxProposerIndicesCacheSize), cache.Len())
+}
--- a/beacon-chain/cache/skip_slot_cache.go
+++ b/beacon-chain/cache/skip_slot_cache.go
@@ -15,11 +15,6 @@ import (
 )

 var (
-	// Delay parameters
-	minDelay    = float64(10)        // 10 nanoseconds
-	maxDelay    = float64(100000000) // 0.1 second
-	delayFactor = 1.1
-
 	// Metrics
 	skipSlotCacheHit = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "skip_slot_cache_hit",
--- a/beacon-chain/cache/subnet_ids.go
+++ b/beacon-chain/cache/subnet_ids.go
@@ -24,8 +24,6 @@ type subnetIDs struct {
 // SubnetIDs for attester and aggregator.
 var SubnetIDs = newSubnetIDs()

-var subnetKey = "persistent-subnets"
-
 func newSubnetIDs() *subnetIDs {
 	// Given a node can calculate committee assignments of current epoch and next epoch.
 	// Max size is set to 2 epoch length.
@@ -93,11 +91,11 @@ func (s *subnetIDs) GetAggregatorSubnetIDs(slot primitives.Slot) []uint64 {

 // GetPersistentSubnets retrieves the persistent subnet and expiration time of that validator's
 // subscription.
-func (s *subnetIDs) GetPersistentSubnets() ([]uint64, bool, time.Time) {
+func (s *subnetIDs) GetPersistentSubnets(pubkey []byte) ([]uint64, bool, time.Time) {
 	s.subnetsLock.RLock()
 	defer s.subnetsLock.RUnlock()

-	id, duration, ok := s.persistentSubnets.GetWithExpiration(subnetKey)
+	id, duration, ok := s.persistentSubnets.GetWithExpiration(string(pubkey))
 	if !ok {
 		return []uint64{}, ok, time.Time{}
 	}
@@ -124,11 +122,11 @@ func (s *subnetIDs) GetAllSubnets() []uint64 {

 // AddPersistentCommittee adds the relevant committee for that particular validator along with its
 // expiration period.
-func (s *subnetIDs) AddPersistentCommittee(comIndex []uint64, duration time.Duration) {
+func (s *subnetIDs) AddPersistentCommittee(pubkey []byte, comIndex []uint64, duration time.Duration) {
 	s.subnetsLock.Lock()
 	defer s.subnetsLock.Unlock()

-	s.persistentSubnets.Set(subnetKey, comIndex, duration)
+	s.persistentSubnets.Set(string(pubkey), comIndex, duration)
 }

 // EmptyAllCaches empties out all the related caches and flushes any stored
--- a/beacon-chain/cache/subnet_ids_test.go
+++ b/beacon-chain/cache/subnet_ids_test.go
@@ -3,8 +3,10 @@ package cache
 import (
 	"testing"

+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

 func TestSubnetIDsCache_RoundTrip(t *testing.T) {
@@ -44,8 +46,21 @@ func TestSubnetIDsCache_RoundTrip(t *testing.T) {
 func TestSubnetIDsCache_PersistentCommitteeRoundtrip(t *testing.T) {
 	c := newSubnetIDs()

-	c.AddPersistentCommittee([]uint64{0, 1, 2, 7, 8}, 0)
+	for i := 0; i < 20; i++ {
+		pubkey := [fieldparams.BLSPubkeyLength]byte{byte(i)}
+		c.AddPersistentCommittee(pubkey[:], []uint64{uint64(i)}, 0)
+	}

+	for i := uint64(0); i < 20; i++ {
+		pubkey := [fieldparams.BLSPubkeyLength]byte{byte(i)}
+
+		idxs, ok, _ := c.GetPersistentSubnets(pubkey[:])
+		if !ok {
+			t.Errorf("Couldn't find entry in cache for pubkey %#x", pubkey)
+			continue
+		}
+		require.Equal(t, i, idxs[0])
+	}
 	coms := c.GetAllSubnets()
-	assert.Equal(t, 5, len(coms))
+	assert.Equal(t, 20, len(coms))
 }
--- a/beacon-chain/cache/tracked_validators.go
+++ b/beacon-chain/cache/tracked_validators.go
@@ -1,43 +0,0 @@
-package cache
-
-import (
-	"sync"
-
-	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
-)
-
-type TrackedValidator struct {
-	Active       bool
-	FeeRecipient primitives.ExecutionAddress
-	Index        primitives.ValidatorIndex
-}
-
-type TrackedValidatorsCache struct {
-	sync.Mutex
-	trackedValidators map[primitives.ValidatorIndex]TrackedValidator
-}
-
-func NewTrackedValidatorsCache() *TrackedValidatorsCache {
-	return &TrackedValidatorsCache{
-		trackedValidators: make(map[primitives.ValidatorIndex]TrackedValidator),
-	}
-}
-
-func (t *TrackedValidatorsCache) Validator(index primitives.ValidatorIndex) (TrackedValidator, bool) {
-	t.Lock()
-	defer t.Unlock()
-	val, ok := t.trackedValidators[index]
-	return val, ok
-}
-
-func (t *TrackedValidatorsCache) Set(val TrackedValidator) {
-	t.Lock()
-	defer t.Unlock()
-	t.trackedValidators[val.Index] = val
-}
-
-func (t *TrackedValidatorsCache) Prune() {
-	t.Lock()
-	defer t.Unlock()
-	t.trackedValidators = make(map[primitives.ValidatorIndex]TrackedValidator)
-}
--- a/beacon-chain/core/altair/attestation.go
+++ b/beacon-chain/core/altair/attestation.go
@@ -24,12 +24,12 @@ import (
 func ProcessAttestationsNoVerifySignature(
 	ctx context.Context,
 	beaconState state.BeaconState,
-	b interfaces.ReadOnlyBeaconBlock,
+	b interfaces.ReadOnlySignedBeaconBlock,
 ) (state.BeaconState, error) {
-	if b == nil || b.IsNil() {
-		return nil, consensusblocks.ErrNilBeaconBlock
+	if err := consensusblocks.BeaconBlockIsNil(b); err != nil {
+		return nil, err
 	}
-	body := b.Body()
+	body := b.Block().Body()
 	totalBalance, err := helpers.TotalActiveBalance(beaconState)
 	if err != nil {
 		return nil, err
--- a/beacon-chain/core/altair/attestation_test.go
+++ b/beacon-chain/core/altair/attestation_test.go
@@ -50,7 +50,7 @@ func TestProcessAttestations_InclusionDelayFailure(t *testing.T) {
 	)
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
 }

@@ -81,7 +81,7 @@ func TestProcessAttestations_NeitherCurrentNorPrevEpoch(t *testing.T) {
 	)
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
 }

@@ -110,13 +110,13 @@ func TestProcessAttestations_CurrentEpochFFGDataMismatches(t *testing.T) {
 	want := "source check point not equal to current justified checkpoint"
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
 	b.Block.Body.Attestations[0].Data.Source.Epoch = time.CurrentEpoch(beaconState)
 	b.Block.Body.Attestations[0].Data.Source.Root = []byte{}
 	wsb, err = blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
 }

@@ -151,14 +151,14 @@ func TestProcessAttestations_PrevEpochFFGDataMismatches(t *testing.T) {
 	want := "source check point not equal to previous justified checkpoint"
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
 	b.Block.Body.Attestations[0].Data.Source.Epoch = time.PrevEpoch(beaconState)
 	b.Block.Body.Attestations[0].Data.Target.Epoch = time.PrevEpoch(beaconState)
 	b.Block.Body.Attestations[0].Data.Source.Root = []byte{}
 	wsb, err = blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
 }

@@ -190,7 +190,7 @@ func TestProcessAttestations_InvalidAggregationBitsLength(t *testing.T) {
 	expected := "failed to verify aggregation bitfield: wanted participants bitfield length 3, got: 4"
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, expected, err)
 }

@@ -234,7 +234,7 @@ func TestProcessAttestations_OK(t *testing.T) {
 	require.NoError(t, err)
 	wsb, err := blocks.NewSignedBeaconBlock(block)
 	require.NoError(t, err)
-	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb.Block())
+	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.NoError(t, err)
 }

@@ -426,7 +426,7 @@ func TestFuzzProcessAttestationsNoVerify_10000(t *testing.T) {
 		}
 		wsb, err := blocks.NewSignedBeaconBlock(b)
 		require.NoError(t, err)
-		r, err := altair.ProcessAttestationsNoVerifySignature(context.Background(), s, wsb.Block())
+		r, err := altair.ProcessAttestationsNoVerifySignature(context.Background(), s, wsb)
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and block: %v", r, err, s, b)
 		}
--- a/beacon-chain/core/altair/epoch_precompute.go
+++ b/beacon-chain/core/altair/epoch_precompute.go
@@ -24,7 +24,7 @@ type AttDelta struct {

 // InitializePrecomputeValidators precomputes individual validator for its attested balances and the total sum of validators attested balances of the epoch.
 func InitializePrecomputeValidators(ctx context.Context, beaconState state.BeaconState) ([]*precompute.Validator, *precompute.Balance, error) {
-	_, span := trace.StartSpan(ctx, "altair.InitializePrecomputeValidators")
+	ctx, span := trace.StartSpan(ctx, "altair.InitializePrecomputeValidators")
 	defer span.End()
 	vals := make([]*precompute.Validator, beaconState.NumValidators())
 	bal := &precompute.Balance{}
@@ -86,7 +86,7 @@ func ProcessInactivityScores(
 	beaconState state.BeaconState,
 	vals []*precompute.Validator,
 ) (state.BeaconState, []*precompute.Validator, error) {
-	_, span := trace.StartSpan(ctx, "altair.ProcessInactivityScores")
+	ctx, span := trace.StartSpan(ctx, "altair.ProcessInactivityScores")
 	defer span.End()

 	cfg := params.BeaconConfig()
@@ -155,7 +155,7 @@ func ProcessEpochParticipation(
 	bal *precompute.Balance,
 	vals []*precompute.Validator,
 ) ([]*precompute.Validator, *precompute.Balance, error) {
-	_, span := trace.StartSpan(ctx, "altair.ProcessEpochParticipation")
+	ctx, span := trace.StartSpan(ctx, "altair.ProcessEpochParticipation")
 	defer span.End()

 	cp, err := beaconState.CurrentEpochParticipation()
--- a/beacon-chain/core/altair/sync_committee_test.go
+++ b/beacon-chain/core/altair/sync_committee_test.go
@@ -276,7 +276,7 @@ func TestSyncSubCommitteePubkeys_CanGet(t *testing.T) {
 }

 func Test_ValidateSyncMessageTime(t *testing.T) {
-	if params.BeaconConfig().MaximumGossipClockDisparityDuration() < 200*time.Millisecond {
+	if params.BeaconNetworkConfig().MaximumGossipClockDisparity < 200*time.Millisecond {
 		t.Fatal("This test expects the maximum clock disparity to be at least 200ms")
 	}

@@ -326,7 +326,7 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot == current_slot+CLOCK_DISPARITY",
 			args: args{
 				syncMessageSlot: 100,
-				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second - params.BeaconConfig().MaximumGossipClockDisparityDuration())),
+				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second - params.BeaconNetworkConfig().MaximumGossipClockDisparity)),
 			},
 			wantedErr: "",
 		},
@@ -334,7 +334,7 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot == current_slot+CLOCK_DISPARITY-1000ms",
 			args: args{
 				syncMessageSlot: 100,
-				genesisTime:     prysmTime.Now().Add(-(100 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second) + params.BeaconConfig().MaximumGossipClockDisparityDuration() + 1000*time.Millisecond),
+				genesisTime:     prysmTime.Now().Add(-(100 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second) + params.BeaconNetworkConfig().MaximumGossipClockDisparity + 1000*time.Millisecond),
 			},
 			wantedErr: "(message slot 100) not within allowable range of",
 		},
@@ -342,7 +342,7 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot == current_slot-CLOCK_DISPARITY",
 			args: args{
 				syncMessageSlot: 100,
-				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second + params.BeaconConfig().MaximumGossipClockDisparityDuration())),
+				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second + params.BeaconNetworkConfig().MaximumGossipClockDisparity)),
 			},
 			wantedErr: "",
 		},
@@ -350,7 +350,7 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot > current_slot+CLOCK_DISPARITY",
 			args: args{
 				syncMessageSlot: 101,
-				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second + params.BeaconConfig().MaximumGossipClockDisparityDuration())),
+				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second + params.BeaconNetworkConfig().MaximumGossipClockDisparity)),
 			},
 			wantedErr: "(message slot 101) not within allowable range of",
 		},
@@ -366,7 +366,7 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			err := altair.ValidateSyncMessageTime(tt.args.syncMessageSlot, tt.args.genesisTime,
-				params.BeaconConfig().MaximumGossipClockDisparityDuration())
+				params.BeaconNetworkConfig().MaximumGossipClockDisparity)
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
--- a/beacon-chain/core/blocks/attestation.go
+++ b/beacon-chain/core/blocks/attestation.go
@@ -25,12 +25,12 @@ import (
 func ProcessAttestationsNoVerifySignature(
 	ctx context.Context,
 	beaconState state.BeaconState,
-	b interfaces.ReadOnlyBeaconBlock,
+	b interfaces.ReadOnlySignedBeaconBlock,
 ) (state.BeaconState, error) {
-	if b == nil || b.IsNil() {
-		return nil, blocks.ErrNilBeaconBlock
+	if err := blocks.BeaconBlockIsNil(b); err != nil {
+		return nil, err
 	}
-	body := b.Body()
+	body := b.Block().Body()
 	var err error
 	for idx, att := range body.Attestations() {
 		beaconState, err = ProcessAttestationNoVerifySignature(ctx, beaconState, att)
--- a/beacon-chain/core/blocks/block_operations_fuzz_test.go
+++ b/beacon-chain/core/blocks/block_operations_fuzz_test.go
@@ -275,7 +275,7 @@ func TestFuzzProcessAttestationsNoVerify_10000(t *testing.T) {
 		}
 		wsb, err := blocks.NewSignedBeaconBlock(b)
 		require.NoError(t, err)
-		r, err := ProcessAttestationsNoVerifySignature(ctx, s, wsb.Block())
+		r, err := ProcessAttestationsNoVerifySignature(ctx, s, wsb)
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and block: %v", r, err, state, b)
 		}
--- a/beacon-chain/core/blocks/exit.go
+++ b/beacon-chain/core/blocks/exit.go
@@ -76,7 +76,7 @@ func ProcessVoluntaryExits(
 			} else if exitEpoch == maxExitEpoch {
 				churn++
 			}
-		} else if !errors.Is(err, v.ErrValidatorAlreadyExited) {
+		} else if !errors.Is(err, v.ValidatorAlreadyExitedErr) {
 			return nil, err
 		}
 	}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Kasey Kirkham	f7cf17149f	add missing bazel build file	2023-12-01 09:49:52 -06:00
Kasey Kirkham	1c3df826f4	lock wrapper for safer forkchoice sharing	2023-11-22 14:49:23 -06:00
@@ -1 +1 @@
 .0.0
 .3.2