fix it

Merge branch 'develop' of https://github.com/prysmaticlabs/geth-sharding into optimizeMVSlice
2026-01-11 06:18:05 -05:00 · 2023-11-24 17:16:46 +08:00 · 2023-11-24 16:37:24 +08:00 · 2023-11-24 16:12:25 +08:00 · 2023-10-21 22:47:17 +08:00 · 2023-10-11 23:36:03 +08:00
2730 changed files with 77331 additions and 76398 deletions
--- a/.bazelrc
+++ b/.bazelrc
@@ -6,12 +6,6 @@ import %workspace%/build/bazelrc/debug.bazelrc
 import %workspace%/build/bazelrc/hermetic-cc.bazelrc
 import %workspace%/build/bazelrc/performance.bazelrc

-# hermetic_cc_toolchain v3.0.1 required changes.
-common --enable_platform_specific_config
-build:linux --sandbox_add_mount_pair=/tmp
-build:macos --sandbox_add_mount_pair=/var/tmp
-build:windows --sandbox_add_mount_pair=C:\Temp
-
 # E2E run with debug gotag
 test:e2e --define gotags=debug

--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-7.1.0
+6.3.2
--- a/.buildkite-bazelrc
+++ b/.buildkite-bazelrc
@@ -9,8 +9,8 @@
 #build:remote-cache --strategy=Genrule=standalone

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

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

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

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

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

 COPY entrypoint.sh /entrypoint.sh

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

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

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

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

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

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

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

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

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

 prefix = "github.com/prysmaticlabs/prysm"

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

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

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

 config_setting(
--- a/DEPENDENCIES.md
+++ b/DEPENDENCIES.md
@@ -55,7 +55,7 @@ bazel build //beacon-chain --config=release
 ## Adding / updating dependencies

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

 Example:

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

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

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

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

 ### Getting Started

--- a/186
+++ b/186
@@ -16,14 +16,12 @@ load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")

 rules_pkg_dependencies()

-HERMETIC_CC_TOOLCHAIN_VERSION = "v3.0.1"
-
 http_archive(
    name = "hermetic_cc_toolchain",
-    sha256 = "3bc6ec127622fdceb4129cb06b6f7ab098c4d539124dde96a6318e7c32a53f7a",
+    sha256 = "973ab22945b921ef45b8e1d6ce01ca7ce1b8a462167449a36e297438c4ec2755",
+    strip_prefix = "hermetic_cc_toolchain-5098046bccc15d2962f3cc8e7e53d6a2a26072dc",
    urls = [
-        "https://mirror.bazel.build/github.com/uber/hermetic_cc_toolchain/releases/download/{0}/hermetic_cc_toolchain-{0}.tar.gz".format(HERMETIC_CC_TOOLCHAIN_VERSION),
-        "https://github.com/uber/hermetic_cc_toolchain/releases/download/{0}/hermetic_cc_toolchain-{0}.tar.gz".format(HERMETIC_CC_TOOLCHAIN_VERSION),
+        "https://github.com/uber/hermetic_cc_toolchain/archive/5098046bccc15d2962f3cc8e7e53d6a2a26072dc.tar.gz",  # 2023-06-28
    ],
 )

@@ -83,10 +81,10 @@ bazel_skylib_workspace()

 http_archive(
    name = "bazel_gazelle",
-    integrity = "sha256-MpOL2hbmcABjA1R5Bj2dJMYO2o15/Uc5Vj9Q0zHLMgk=",
+    sha256 = "d3fa66a39028e97d76f9e2db8f1b0c11c099e8e01bf363a923074784e451f809",
    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.35.0/bazel-gazelle-v0.35.0.tar.gz",
-        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.35.0/bazel-gazelle-v0.35.0.tar.gz",
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.33.0/bazel-gazelle-v0.33.0.tar.gz",
+        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.33.0/bazel-gazelle-v0.33.0.tar.gz",
    ],
 )

@@ -98,36 +96,11 @@ http_archive(
 )

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

-load("@rules_distroless//distroless:dependencies.bzl", "rules_distroless_dependencies")
-
-rules_distroless_dependencies()
-
-http_archive(
-    name = "distroless",
-    integrity = "sha256-Cf00kUp1NyXA3LzbdyYy4Kda27wbkB8+A9MliTxq4jE=",
-    strip_prefix = "distroless-9dc924b9fe812eec2fa0061824dcad39eb09d0d6",
-    url = "https://github.com/GoogleContainerTools/distroless/archive/9dc924b9fe812eec2fa0061824dcad39eb09d0d6.tar.gz",  # 2024-01-24
-)
-
-http_archive(
-    name = "aspect_bazel_lib",
-    sha256 = "f5ea76682b209cc0bd90d0f5a3b26d2f7a6a2885f0c5f615e72913f4805dbb0d",
-    strip_prefix = "bazel-lib-2.5.0",
-    url = "https://github.com/aspect-build/bazel-lib/releases/download/v2.5.0/bazel-lib-v2.5.0.tar.gz",
-)
-
-load("@aspect_bazel_lib//lib:repositories.bzl", "aspect_bazel_lib_dependencies", "aspect_bazel_lib_register_toolchains")
-
-aspect_bazel_lib_dependencies()
-
-aspect_bazel_lib_register_toolchains()
-
 http_archive(
    name = "rules_oci",
    sha256 = "c71c25ed333a4909d2dd77e0b16c39e9912525a98c7fa85144282be8d04ef54c",
@@ -153,10 +126,10 @@ http_archive(
        # Expose internals of go_test for custom build transitions.
        "//third_party:io_bazel_rules_go_test.patch",
    ],
-    sha256 = "80a98277ad1311dacd837f9b16db62887702e9f1d1c4c9f796d0121a46c8e184",
+    sha256 = "91585017debb61982f7054c9688857a2ad1fd823fc3f9cb05048b0025c47d023",
    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.46.0/rules_go-v0.46.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.46.0/rules_go-v0.46.0.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",
    ],
 )

@@ -175,16 +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,
 )
@@ -198,14 +222,10 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()

 go_register_toolchains(
-    go_version = "1.21.8",
+    go_version = "1.20.10",
    nogo = "@//:nogo",
 )

-load("//:distroless_deps.bzl", "distroless_deps")
-
-distroless_deps()
-
 http_archive(
    name = "io_kubernetes_build",
    sha256 = "b84fbd1173acee9d02a7d3698ad269fdf4f7aa081e9cecd40e012ad0ad8cfa2a",
@@ -224,8 +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(
@@ -243,9 +263,7 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

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

 bls_test_version = "v0.1.1"

@@ -261,8 +279,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "c282c0f86f23f3d2e0f71f5975769a4077e62a7e3c7382a16bd26a7e589811a0",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_test_version,
+    sha256 = "67ae5b8fc368853da23d4297e480a4b7f4722fb970d1c7e2b6a5b7faef9cb907",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

 http_archive(
@@ -277,8 +295,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "4649c35aa3b8eb0cfdc81bee7c05649f90ef36bede5b0513e1f2e8baf37d6033",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_test_version,
+    sha256 = "82474f29fff4abd09fb1e71bafa98827e2573cf0ad02cf119610961831dc3bb5",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

 http_archive(
@@ -293,8 +311,8 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "c5a03f724f757456ffaabd2a899992a71d2baf45ee4db65ca3518f2b7ee928c8",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_test_version,
+    sha256 = "60e4b6eb6c341daab7ee5614a8e3f28567247c504c593b951bfe919622c8ef8f",
+    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

 http_archive(
@@ -308,7 +326,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "049c29267310e6b88280f4f834a75866c2f5b9036fa97acb9d9c6db8f64d9118",
+    sha256 = "fdab9756c93a250219ff6a10d5a9faee1e2e6878a14508410409e307362c6991",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -339,25 +357,9 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "77e7e3ed65e33b7bb19d30131f4c2bb39e4dfeb188ab9ae84651c3cc7600131d",
-    strip_prefix = "eth2-networks-934c948e69205dcf2deb87e4ae6cc140c335f94d",
-    url = "https://github.com/eth-clients/eth2-networks/archive/934c948e69205dcf2deb87e4ae6cc140c335f94d.tar.gz",
-)
-
-http_archive(
-    name = "goerli_testnet",
-    build_file_content = """
-filegroup(
-    name = "configs",
-    srcs = [
-        "prater/config.yaml",
-    ],
-    visibility = ["//visibility:public"],
-)
-    """,
-    sha256 = "43fc0f55ddff7b511713e2de07aa22846a67432df997296fb4fc09cd8ed1dcdb",
-    strip_prefix = "goerli-6522ac6684693740cd4ddcc2a0662e03702aa4a1",
-    url = "https://github.com/eth-clients/goerli/archive/6522ac6684693740cd4ddcc2a0662e03702aa4a1.tar.gz",
+    sha256 = "2701e1e1a3ec10c673fe7dbdbbe6f02c8ae8c922aebbf6e720d8c72d5458aafe",
+    strip_prefix = "eth2-networks-7b4897888cebef23801540236f73123e21774954",
+    url = "https://github.com/eth-clients/eth2-networks/archive/7b4897888cebef23801540236f73123e21774954.tar.gz",
 )

 http_archive(
@@ -371,17 +373,17 @@ filegroup(
    visibility = ["//visibility:public"],
 )
 """,
-    sha256 = "5f4be6fd088683ea9db45c863b9c5a1884422449e5b59fd2d561d3ba0f73ffd9",
-    strip_prefix = "holesky-9d9aabf2d4de51334ee5fed6c79a4d55097d1a43",
-    url = "https://github.com/eth-clients/holesky/archive/9d9aabf2d4de51334ee5fed6c79a4d55097d1a43.tar.gz",  # 2024-01-22
+    sha256 = "9f66d8d5644982d3d0d2e3d2b9ebe77a5f96638a5d7fcd715599c32818195cb3",
+    strip_prefix = "holesky-ea39b9006210848e13f28d92e12a30548cecd41d",
+    url = "https://github.com/eth-clients/holesky/archive/ea39b9006210848e13f28d92e12a30548cecd41d.tar.gz",  # 2023-09-21
 )

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

@@ -415,6 +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",
-    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api",
+    srcs = ["headers.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v4/api",
    visibility = ["//visibility:public"],
 )
--- a/api/client/BUILD.bazel
+++ b/api/client/BUILD.bazel
@@ -7,7 +7,7 @@ go_library(
        "errors.go",
        "options.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client",
    visibility = ["//visibility:public"],
    deps = ["@com_github_pkg_errors//:go_default_library"],
 )
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -6,17 +6,16 @@ go_library(
        "checkpoint.go",
        "client.go",
        "doc.go",
-        "health.go",
-        "log.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/beacon",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/beacon",
    visibility = ["//visibility:public"],
    deps = [
        "//api/client:go_default_library",
-        "//api/client/beacon/iface:go_default_library",
-        "//api/server:go_default_library",
-        "//api/server/structs:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/rpc/apimiddleware:go_default_library",
+        "//beacon-chain/rpc/eth/beacon:go_default_library",
+        "//beacon-chain/rpc/eth/config:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
@@ -39,12 +38,10 @@ go_test(
    srcs = [
        "checkpoint_test.go",
        "client_test.go",
-        "health_test.go",
    ],
    embed = [":go_default_library"],
    deps = [
        "//api/client:go_default_library",
-        "//api/client/beacon/testing:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
@@ -58,6 +55,5 @@ go_test(
        "//testing/util:go_default_library",
        "//time/slots:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
-        "@org_uber_go_mock//gomock:go_default_library",
    ],
 )
--- a/api/client/beacon/checkpoint.go
+++ b/api/client/beacon/checkpoint.go
@@ -7,17 +7,17 @@ import (

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

@@ -74,12 +74,7 @@ func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, er
 	if err != nil {
 		return nil, errors.Wrap(err, "error detecting chain config for finalized state")
 	}
-
-	log.WithFields(logrus.Fields{
-		"name": vu.Config.ConfigName,
-		"fork": version.String(vu.Fork),
-	}).Info("Detected supported config in remote finalized state")
-
+	log.Printf("detected supported config in remote finalized state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
 	s, err := vu.UnmarshalBeaconState(sb)
 	if err != nil {
 		return nil, errors.Wrap(err, "error unmarshaling finalized state to correct version")
@@ -113,10 +108,10 @@ func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, er
 	}

 	log.
-		WithField("blockSlot", b.Block().Slot()).
-		WithField("stateSlot", s.Slot()).
-		WithField("stateRoot", hexutil.Encode(sr[:])).
-		WithField("blockRoot", hexutil.Encode(br[:])).
+		WithField("block_slot", b.Block().Slot()).
+		WithField("state_slot", s.Slot()).
+		WithField("state_root", hexutil.Encode(sr[:])).
+		WithField("block_root", hexutil.Encode(br[:])).
 		Info("Downloaded checkpoint sync state and block.")
 	return &OriginData{
 		st: s,
--- a/api/client/beacon/checkpoint_test.go
+++ b/api/client/beacon/checkpoint_test.go
@@ -9,22 +9,22 @@ import (
 	"net/http"
 	"testing"

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

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

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

 type testRT struct {
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -15,21 +15,23 @@ import (

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

 const (
 	getSignedBlockPath       = "/eth/v2/beacon/blocks"
 	getBlockRootPath         = "/eth/v1/beacon/blocks/{{.Id}}/root"
 	getForkForStatePath      = "/eth/v1/beacon/states/{{.Id}}/fork"
-	getWeakSubjectivityPath  = "/prysm/v1/beacon/weak_subjectivity"
+	getWeakSubjectivityPath  = "/eth/v1/beacon/weak_subjectivity"
 	getForkSchedulePath      = "/eth/v1/config/fork_schedule"
 	getConfigSpecPath        = "/eth/v1/config/spec"
 	getStatePath             = "/eth/v2/debug/beacon/states"
@@ -147,8 +149,8 @@ func (c *Client) GetFork(ctx context.Context, stateId StateOrBlockId) (*ethpb.Fo
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting fork by state id = %s", stateId)
 	}
-	fr := &structs.Fork{}
-	dataWrapper := &struct{ Data *structs.Fork }{Data: fr}
+	fr := &shared.Fork{}
+	dataWrapper := &struct{ Data *shared.Fork }{Data: fr}
 	err = json.Unmarshal(body, dataWrapper)
 	if err != nil {
 		return nil, errors.Wrap(err, "error decoding json response in GetFork")
@@ -176,12 +178,12 @@ func (c *Client) GetForkSchedule(ctx context.Context) (forks.OrderedSchedule, er
 }

 // GetConfigSpec retrieve the current configs of the network used by the beacon node.
-func (c *Client) GetConfigSpec(ctx context.Context) (*structs.GetSpecResponse, error) {
+func (c *Client) GetConfigSpec(ctx context.Context) (*config.GetSpecResponse, error) {
 	body, err := c.Get(ctx, getConfigSpecPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting configSpecPath")
 	}
-	fsr := &structs.GetSpecResponse{}
+	fsr := &config.GetSpecResponse{}
 	err = json.Unmarshal(body, fsr)
 	if err != nil {
 		return nil, err
@@ -256,16 +258,16 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 	if err != nil {
 		return nil, err
 	}
-	v := &structs.GetWeakSubjectivityResponse{}
+	v := &apimiddleware.WeakSubjectivityResponse{}
 	err = json.Unmarshal(body, v)
 	if err != nil {
 		return nil, err
 	}
-	epoch, err := strconv.ParseUint(v.Data.WsCheckpoint.Epoch, 10, 64)
+	epoch, err := strconv.ParseUint(v.Data.Checkpoint.Epoch, 10, 64)
 	if err != nil {
 		return nil, err
 	}
-	blockRoot, err := hexutil.Decode(v.Data.WsCheckpoint.Root)
+	blockRoot, err := hexutil.Decode(v.Data.Checkpoint.Root)
 	if err != nil {
 		return nil, err
 	}
@@ -282,7 +284,7 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData

 // SubmitChangeBLStoExecution calls a beacon API endpoint to set the withdrawal addresses based on the given signed messages.
 // If the API responds with something other than OK there will be failure messages associated to the corresponding request message.
-func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*structs.SignedBLSToExecutionChange) error {
+func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*shared.SignedBLSToExecutionChange) error {
 	u := c.BaseURL().ResolveReference(&url.URL{Path: changeBLStoExecutionPath})
 	body, err := json.Marshal(request)
 	if err != nil {
@@ -303,15 +305,15 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*stru
 	if resp.StatusCode != http.StatusOK {
 		decoder := json.NewDecoder(resp.Body)
 		decoder.DisallowUnknownFields()
-		errorJson := &server.IndexedVerificationFailureError{}
+		errorJson := &apimiddleware.IndexedVerificationFailureErrorJson{}
 		if err := decoder.Decode(errorJson); err != nil {
 			return errors.Wrapf(err, "failed to decode error JSON for %s", resp.Request.URL)
 		}
 		for _, failure := range errorJson.Failures {
 			w := request[failure.Index].Message
-			log.WithFields(logrus.Fields{
-				"validatorIndex":    w.ValidatorIndex,
-				"withdrawalAddress": w.ToExecutionAddress,
+			log.WithFields(log.Fields{
+				"validator_index":    w.ValidatorIndex,
+				"withdrawal_address": w.ToExecutionAddress,
 			}).Error(failure.Message)
 		}
 		return errors.Errorf("POST error %d: %s", errorJson.Code, errorJson.Message)
@@ -321,12 +323,12 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*stru

 // GetBLStoExecutionChanges gets all the set withdrawal messages in the node's operation pool.
 // Returns a struct representation of json response.
-func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToExecutionChangesPoolResponse, error) {
+func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*beacon.BLSToExecutionChangesPoolResponse, error) {
 	body, err := c.Get(ctx, changeBLStoExecutionPath)
 	if err != nil {
 		return nil, err
 	}
-	poolResponse := &structs.BLSToExecutionChangesPoolResponse{}
+	poolResponse := &beacon.BLSToExecutionChangesPoolResponse{}
 	err = json.Unmarshal(body, poolResponse)
 	if err != nil {
 		return nil, err
@@ -335,15 +337,15 @@ func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToEx
 }

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

 func (fsr *forkScheduleResponse) OrderedForkSchedule() (forks.OrderedSchedule, error) {
 	ofs := make(forks.OrderedSchedule, 0)
 	for _, d := range fsr.Data {
-		epoch, err := strconv.ParseUint(d.Epoch, 10, 64)
+		epoch, err := strconv.Atoi(d.Epoch)
 		if err != nil {
-			return nil, errors.Wrapf(err, "error parsing epoch %s", d.Epoch)
+			return nil, err
 		}
 		vSlice, err := hexutil.Decode(d.CurrentVersion)
 		if err != nil {
@@ -355,7 +357,7 @@ func (fsr *forkScheduleResponse) OrderedForkSchedule() (forks.OrderedSchedule, e
 		version := bytesutil.ToBytes4(vSlice)
 		ofs = append(ofs, forks.ForkScheduleEntry{
 			Version: version,
-			Epoch:   primitives.Epoch(epoch),
+			Epoch:   primitives.Epoch(uint64(epoch)),
 		})
 	}
 	sort.Sort(ofs)
--- a/api/client/beacon/client_test.go
+++ b/api/client/beacon/client_test.go
@@ -4,8 +4,8 @@ import (
 	"net/url"
 	"testing"

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

 func TestParseNodeVersion(t *testing.T) {
--- a/api/client/beacon/health.go
+++ b/api/client/beacon/health.go
@@ -1,55 +0,0 @@
-package beacon
-
-import (
-	"context"
-	"sync"
-
-	"github.com/prysmaticlabs/prysm/v5/api/client/beacon/iface"
-)
-
-type NodeHealthTracker struct {
-	isHealthy  *bool
-	healthChan chan bool
-	node       iface.HealthNode
-	sync.RWMutex
-}
-
-func NewNodeHealthTracker(node iface.HealthNode) *NodeHealthTracker {
-	return &NodeHealthTracker{
-		node:       node,
-		healthChan: make(chan bool, 1),
-	}
-}
-
-// HealthUpdates provides a read-only channel for health updates.
-func (n *NodeHealthTracker) HealthUpdates() <-chan bool {
-	return n.healthChan
-}
-
-func (n *NodeHealthTracker) IsHealthy() bool {
-	n.RLock()
-	defer n.RUnlock()
-	if n.isHealthy == nil {
-		return false
-	}
-	return *n.isHealthy
-}
-
-func (n *NodeHealthTracker) CheckHealth(ctx context.Context) bool {
-	n.RLock()
-	newStatus := n.node.IsHealthy(ctx)
-	if n.isHealthy == nil {
-		n.isHealthy = &newStatus
-	}
-	isStatusChanged := newStatus != *n.isHealthy
-	n.RUnlock()
-
-	if isStatusChanged {
-		n.Lock()
-		// Double-check the condition to ensure it hasn't changed since the first check.
-		n.isHealthy = &newStatus
-		n.Unlock() // It's better to unlock as soon as the protected section is over.
-		n.healthChan <- newStatus
-	}
-	return newStatus
-}
--- a/api/client/beacon/health_test.go
+++ b/api/client/beacon/health_test.go
@@ -1,118 +0,0 @@
-package beacon
-
-import (
-	"context"
-	"sync"
-	"testing"
-
-	healthTesting "github.com/prysmaticlabs/prysm/v5/api/client/beacon/testing"
-	"go.uber.org/mock/gomock"
-)
-
-func TestNodeHealth_IsHealthy(t *testing.T) {
-	tests := []struct {
-		name      string
-		isHealthy bool
-		want      bool
-	}{
-		{"initially healthy", true, true},
-		{"initially unhealthy", false, false},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			n := &NodeHealthTracker{
-				isHealthy:  &tt.isHealthy,
-				healthChan: make(chan bool, 1),
-			}
-			if got := n.IsHealthy(); got != tt.want {
-				t.Errorf("IsHealthy() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestNodeHealth_UpdateNodeHealth(t *testing.T) {
-	tests := []struct {
-		name       string
-		initial    bool // Initial health status
-		newStatus  bool // Status to update to
-		shouldSend bool // Should a message be sent through the channel
-	}{
-		{"healthy to unhealthy", true, false, true},
-		{"unhealthy to healthy", false, true, true},
-		{"remain healthy", true, true, false},
-		{"remain unhealthy", false, false, false},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
-			client := healthTesting.NewMockHealthClient(ctrl)
-			client.EXPECT().IsHealthy(gomock.Any()).Return(tt.newStatus)
-			n := &NodeHealthTracker{
-				isHealthy:  &tt.initial,
-				node:       client,
-				healthChan: make(chan bool, 1),
-			}
-
-			s := n.CheckHealth(context.Background())
-			// Check if health status was updated
-			if s != tt.newStatus {
-				t.Errorf("UpdateNodeHealth() failed to update isHealthy from %v to %v", tt.initial, tt.newStatus)
-			}
-
-			select {
-			case status := <-n.HealthUpdates():
-				if !tt.shouldSend {
-					t.Errorf("UpdateNodeHealth() unexpectedly sent status %v to HealthCh", status)
-				} else if status != tt.newStatus {
-					t.Errorf("UpdateNodeHealth() sent wrong status %v, want %v", status, tt.newStatus)
-				}
-			default:
-				if tt.shouldSend {
-					t.Error("UpdateNodeHealth() did not send any status to HealthCh when expected")
-				}
-			}
-		})
-	}
-}
-
-func TestNodeHealth_Concurrency(t *testing.T) {
-	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
-	client := healthTesting.NewMockHealthClient(ctrl)
-	n := NewNodeHealthTracker(client)
-	var wg sync.WaitGroup
-
-	// Number of goroutines to spawn for both reading and writing
-	numGoroutines := 6
-
-	go func() {
-		for range n.HealthUpdates() {
-			// Consume values to avoid blocking on channel send.
-		}
-	}()
-
-	wg.Add(numGoroutines * 2) // for readers and writers
-
-	// Concurrently update health status
-	for i := 0; i < numGoroutines; i++ {
-		go func() {
-			defer wg.Done()
-			client.EXPECT().IsHealthy(gomock.Any()).Return(false)
-			n.CheckHealth(context.Background())
-			client.EXPECT().IsHealthy(gomock.Any()).Return(true)
-			n.CheckHealth(context.Background())
-		}()
-	}
-
-	// Concurrently read health status
-	for i := 0; i < numGoroutines; i++ {
-		go func() {
-			defer wg.Done()
-			_ = n.IsHealthy() // Just read the value
-		}()
-	}
-
-	wg.Wait() // Wait for all goroutines to finish
-}
--- a/api/client/beacon/iface/BUILD.bazel
+++ b/api/client/beacon/iface/BUILD.bazel
@@ -1,8 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library")
-
-go_library(
-    name = "go_default_library",
-    srcs = ["health.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/beacon/iface",
-    visibility = ["//visibility:public"],
-)
--- a/api/client/beacon/iface/health.go
+++ b/api/client/beacon/iface/health.go
@@ -1,13 +0,0 @@
-package iface
-
-import "context"
-
-type HealthTracker interface {
-	HealthUpdates() <-chan bool
-	IsHealthy() bool
-	CheckHealth(ctx context.Context) bool
-}
-
-type HealthNode interface {
-	IsHealthy(ctx context.Context) bool
-}
--- a/api/client/beacon/log.go
+++ b/api/client/beacon/log.go
@@ -1,5 +0,0 @@
-package beacon
-
-import "github.com/sirupsen/logrus"
-
-var log = logrus.WithField("prefix", "beacon")
--- a/api/client/beacon/testing/BUILD.bazel
+++ b/api/client/beacon/testing/BUILD.bazel
@@ -1,12 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library")
-
-go_library(
-    name = "go_default_library",
-    srcs = ["mock.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/beacon/testing",
-    visibility = ["//visibility:public"],
-    deps = [
-        "//api/client/beacon/iface:go_default_library",
-        "@org_uber_go_mock//gomock:go_default_library",
-    ],
-)
--- a/api/client/beacon/testing/mock.go
+++ b/api/client/beacon/testing/mock.go
@@ -1,53 +0,0 @@
-package testing
-
-import (
-	"context"
-	"reflect"
-
-	"github.com/prysmaticlabs/prysm/v5/api/client/beacon/iface"
-	"go.uber.org/mock/gomock"
-)
-
-var (
-	_ = iface.HealthNode(&MockHealthClient{})
-)
-
-// MockHealthClient is a mock of HealthClient interface.
-type MockHealthClient struct {
-	ctrl     *gomock.Controller
-	recorder *MockHealthClientMockRecorder
-}
-
-// MockHealthClientMockRecorder is the mock recorder for MockHealthClient.
-type MockHealthClientMockRecorder struct {
-	mock *MockHealthClient
-}
-
-// IsHealthy mocks base method.
-func (m *MockHealthClient) IsHealthy(arg0 context.Context) bool {
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "IsHealthy", arg0)
-	ret0, ok := ret[0].(bool)
-	if !ok {
-		return false
-	}
-	return ret0
-}
-
-// EXPECT returns an object that allows the caller to indicate expected use.
-func (m *MockHealthClient) EXPECT() *MockHealthClientMockRecorder {
-	return m.recorder
-}
-
-// IsHealthy indicates an expected call of IsHealthy.
-func (mr *MockHealthClientMockRecorder) IsHealthy(arg0 any) *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IsHealthy", reflect.TypeOf((*MockHealthClient)(nil).IsHealthy), arg0)
-}
-
-// NewMockHealthClient creates a new mock instance.
-func NewMockHealthClient(ctrl *gomock.Controller) *MockHealthClient {
-	mock := &MockHealthClient{ctrl: ctrl}
-	mock.recorder = &MockHealthClientMockRecorder{mock}
-	return mock
-}
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -8,10 +8,10 @@ go_library(
        "errors.go",
        "types.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/builder",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/builder",
    visibility = ["//visibility:public"],
    deps = [
-        "//api/server/structs:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//config/fieldparams:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
@@ -20,6 +20,8 @@ go_library(
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//monitoring/tracing:go_default_library",
+        "//network:go_default_library",
+        "//network/authorization:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
@@ -40,7 +42,7 @@ go_test(
    data = glob(["testdata/**"]),
    embed = [":go_default_library"],
    deps = [
-        "//api/server/structs:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
--- a/api/client/builder/bid.go
+++ b/api/client/builder/bid.go
@@ -3,11 +3,12 @@ package builder
 import (
 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
-	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	consensus_types "github.com/prysmaticlabs/prysm/v4/consensus-types"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 )

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

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

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

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

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

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

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

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v4/network"
+	"github.com/prysmaticlabs/prysm/v4/network/authorization"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	log "github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -57,8 +58,8 @@ func (*requestLogger) observe(r *http.Request) (e error) {
 	b := bytes.NewBuffer(nil)
 	if r.Body == nil {
 		log.WithFields(log.Fields{
-			"bodyBase64": "(nil value)",
-			"url":        r.URL.String(),
+			"body-base64": "(nil value)",
+			"url":         r.URL.String(),
 		}).Info("builder http request")
 		return nil
 	}
@@ -74,8 +75,8 @@ func (*requestLogger) observe(r *http.Request) (e error) {
 	}
 	r.Body = io.NopCloser(b)
 	log.WithFields(log.Fields{
-		"bodyBase64": string(body),
-		"url":        r.URL.String(),
+		"body-base64": string(body),
+		"url":         r.URL.String(),
 	}).Info("builder http request")

 	return nil
@@ -88,7 +89,7 @@ type BuilderClient interface {
 	NodeURL() string
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error)
 	Status(ctx context.Context) error
 }

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

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

 type reqOption func(*http.Request)

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

 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
-func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	if !sb.IsBlinded() {
 		return nil, nil, errNotBlinded
 	}
@@ -294,7 +301,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := structs.SignedBlindedBeaconBlockBellatrixFromConsensus(&ethpb.SignedBlindedBeaconBlockBellatrix{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockBellatrixFromConsensus(&ethpb.SignedBlindedBeaconBlockBellatrix{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockBellatrix to json marshalable type")
 		}
@@ -331,7 +338,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := structs.SignedBlindedBeaconBlockCapellaFromConsensus(&ethpb.SignedBlindedBeaconBlockCapella{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockCapellaFromConsensus(&ethpb.SignedBlindedBeaconBlockCapella{Block: psb.Block, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockCapella to json marshalable type")
 		}
@@ -358,7 +365,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
 		}
-		payload, err := blocks.WrappedExecutionPayloadCapella(p, big.NewInt(0))
+		payload, err := blocks.WrappedExecutionPayloadCapella(p, 0)
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
 		}
@@ -368,9 +375,9 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
-		b, err := structs.SignedBlindedBeaconBlockDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockDeneb{Message: psb.Message, Signature: bytesutil.SafeCopyBytes(psb.Signature)})
+		b, err := shared.SignedBlindedBeaconBlockContentsDenebFromConsensus(&ethpb.SignedBlindedBeaconBlockAndBlobsDeneb{SignedBlindedBlock: psb, SignedBlindedBlobSidecars: blobs})
 		if err != nil {
-			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockDeneb to json marshalable type")
+			return nil, nil, errors.Wrapf(err, "could not convert SignedBlindedBeaconBlockContentsDeneb to json marshalable type")
 		}
 		body, err := json.Marshal(b)
 		if err != nil {
@@ -395,7 +402,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
 		}
-		payload, err := blocks.WrappedExecutionPayloadDeneb(p, big.NewInt(0))
+		payload, err := blocks.WrappedExecutionPayloadDeneb(p, 0)
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
 		}
@@ -424,29 +431,38 @@ func non200Err(response *http.Response) error {
 	}
 	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
-	case http.StatusNoContent:
+	case 204:
 		log.WithError(ErrNoContent).Debug(msg)
 		return ErrNoContent
-	case http.StatusBadRequest:
+	case 400:
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		log.WithError(ErrBadRequest).Debug(msg)
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
 		return errors.Wrap(ErrBadRequest, errMessage.Message)
-	case http.StatusNotFound:
+	case 404:
+		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
+			return errors.Wrap(jsonErr, "unable to read response body")
+		}
 		log.WithError(ErrNotFound).Debug(msg)
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
 		return errors.Wrap(ErrNotFound, errMessage.Message)
-	case http.StatusInternalServerError:
-		log.WithError(ErrNotOK).Debug(msg)
+	case 500:
 		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
 			return errors.Wrap(jsonErr, "unable to read response body")
 		}
+		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, errMessage.Message)
 	default:
 		log.WithError(ErrNotOK).Debug(msg)
 		return errors.Wrap(ErrNotOK, fmt.Sprintf("unsupported error code: %d", response.StatusCode))
 	}
 }
+
+func covertEndPoint(ep string) network.Endpoint {
+	return network.Endpoint{
+		Url: ep,
+		Auth: network.AuthorizationData{ // Auth is not used for builder.
+			Method: authorization.None,
+			Value:  "",
+		}}
+}
--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -12,16 +12,18 @@ import (
 	"strconv"
 	"testing"

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

@@ -268,20 +270,28 @@ func TestClient_GetHeader(t *testing.T) {
 		bidValue := bytesutil.ReverseByteOrder(bid.Value())
 		require.DeepEqual(t, bidValue, value.Bytes())
 		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
-		kcgCommitments, err := bid.BlobKzgCommitments()
+		bundle, err := bid.BlindedBlobsBundle()
 		require.NoError(t, err)
-		require.Equal(t, len(kcgCommitments) > 0, true)
-		for i := range kcgCommitments {
-			require.Equal(t, len(kcgCommitments[i]) == 48, true)
+		require.Equal(t, len(bundle.BlobRoots) <= fieldparams.MaxBlobsPerBlock && len(bundle.BlobRoots) > 0, true)
+		for i := range bundle.BlobRoots {
+			require.Equal(t, len(bundle.BlobRoots[i]) == fieldparams.RootLength, true)
+		}
+		require.Equal(t, len(bundle.KzgCommitments) > 0, true)
+		for i := range bundle.KzgCommitments {
+			require.Equal(t, len(bundle.KzgCommitments[i]) == 48, true)
+		}
+		require.Equal(t, len(bundle.Proofs) > 0, true)
+		for i := range bundle.Proofs {
+			require.Equal(t, len(bundle.Proofs[i]) == 48, true)
 		}
 	})
-	t.Run("deneb, too many kzg commitments", func(t *testing.T) {
+	t.Run("deneb, no bundle", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, expectedPath, r.URL.Path)
 				return &http.Response{
 					StatusCode: http.StatusOK,
-					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebTooManyBlobs)),
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDenebNoBundle)),
 					Request:    r.Clone(ctx),
 				}, nil
 			}),
@@ -290,9 +300,27 @@ func TestClient_GetHeader(t *testing.T) {
 			hc:      hc,
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}
-		_, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
-		require.ErrorContains(t, "could not extract proto message from header: too many blob commitments: 7", err)
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+		value, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
+		require.NoError(t, err)
+		require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", bid.Value()))
+		bidValue := bytesutil.ReverseByteOrder(bid.Value())
+		require.DeepEqual(t, bidValue, value.Bytes())
+		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
+		bundle, err := bid.BlindedBlobsBundle()
+		require.NoError(t, err)
+		require.Equal(t, (*v1.BlindedBlobsBundle)(nil), bundle)
 	})
+
 	t.Run("unsupported version", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -334,7 +362,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb, nil)
 		require.NoError(t, err)
 		require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash()))
 		bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
@@ -360,7 +388,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockCapella(t))
 		require.NoError(t, err)
-		ep, _, err := c.SubmitBlindedBlock(ctx, sbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbb, nil)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -371,17 +399,18 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
 	t.Run("deneb", func(t *testing.T) {
-		test := testSignedBlindedBeaconBlockDeneb(t)
+
+		test := testSignedBlindedBeaconBlockAndBlobsDeneb(t)
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
 				require.Equal(t, "deneb", r.Header.Get("Eth-Consensus-Version"))
-				var req structs.SignedBlindedBeaconBlockDeneb
+				var req shared.SignedBlindedBeaconBlockContentsDeneb
 				err := json.NewDecoder(r.Body).Decode(&req)
 				require.NoError(t, err)
-				block, err := req.ToConsensus()
+				block, err := req.SignedBlindedBlock.ToConsensus()
 				require.NoError(t, err)
-				require.DeepEqual(t, block, test)
+				require.DeepEqual(t, block, test.SignedBlindedBlock)
 				return &http.Response{
 					StatusCode: http.StatusOK,
 					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadDeneb)),
@@ -394,10 +423,10 @@ func TestSubmitBlindedBlock(t *testing.T) {
 			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 		}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

 func TestValidHostname(t *testing.T) {
--- a/api/client/errors.go
+++ b/api/client/errors.go
@@ -21,9 +21,6 @@ var ErrNotFound = errors.Wrap(ErrNotOK, "recv 404 NotFound response from API")
 // ErrInvalidNodeVersion indicates that the /eth/v1/node/version API response format was not recognized.
 var ErrInvalidNodeVersion = errors.New("invalid node version response")

-// ErrConnectionIssue represents a connection problem.
-var ErrConnectionIssue = errors.New("could not connect")
-
 // Non200Err is a function that parses an HTTP response to handle responses that are not 200 with a formatted error.
 func Non200Err(response *http.Response) error {
 	bodyBytes, err := io.ReadAll(response.Body)
@@ -35,7 +32,7 @@ func Non200Err(response *http.Response) error {
 	}
 	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
-	case http.StatusNotFound:
+	case 404:
 		return errors.Wrap(ErrNotFound, msg)
 	default:
 		return errors.Wrap(ErrNotOK, msg)
--- a/api/client/event/BUILD.bazel
+++ b/api/client/event/BUILD.bazel
@@ -1,24 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library", "go_test")
-
-go_library(
-    name = "go_default_library",
-    srcs = ["event_stream.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/event",
-    visibility = ["//visibility:public"],
-    deps = [
-        "//api:go_default_library",
-        "//api/client:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
-    ],
-)
-
-go_test(
-    name = "go_default_test",
-    srcs = ["event_stream_test.go"],
-    embed = [":go_default_library"],
-    deps = [
-        "//testing/require:go_default_library",
-        "@com_github_sirupsen_logrus//:go_default_library",
-    ],
-)
--- a/api/client/event/event_stream.go
+++ b/api/client/event/event_stream.go
@@ -1,148 +0,0 @@
-package event
-
-import (
-	"bufio"
-	"context"
-	"net/http"
-	"net/url"
-	"strings"
-
-	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api"
-	"github.com/prysmaticlabs/prysm/v5/api/client"
-	log "github.com/sirupsen/logrus"
-)
-
-const (
-	EventHead                        = "head"
-	EventBlock                       = "block"
-	EventAttestation                 = "attestation"
-	EventVoluntaryExit               = "voluntary_exit"
-	EventBlsToExecutionChange        = "bls_to_execution_change"
-	EventProposerSlashing            = "proposer_slashing"
-	EventAttesterSlashing            = "attester_slashing"
-	EventFinalizedCheckpoint         = "finalized_checkpoint"
-	EventChainReorg                  = "chain_reorg"
-	EventContributionAndProof        = "contribution_and_proof"
-	EventLightClientFinalityUpdate   = "light_client_finality_update"
-	EventLightClientOptimisticUpdate = "light_client_optimistic_update"
-	EventPayloadAttributes           = "payload_attributes"
-	EventBlobSidecar                 = "blob_sidecar"
-	EventError                       = "error"
-	EventConnectionError             = "connection_error"
-)
-
-var (
-	_ = EventStreamClient(&EventStream{})
-)
-
-var DefaultEventTopics = []string{EventHead}
-
-type EventStreamClient interface {
-	Subscribe(eventsChannel chan<- *Event)
-}
-
-type Event struct {
-	EventType string
-	Data      []byte
-}
-
-// EventStream is responsible for subscribing to the Beacon API events endpoint
-// and dispatching received events to subscribers.
-type EventStream struct {
-	ctx        context.Context
-	httpClient *http.Client
-	host       string
-	topics     []string
-}
-
-func NewEventStream(ctx context.Context, httpClient *http.Client, host string, topics []string) (*EventStream, error) {
-	// Check if the host is a valid URL
-	_, err := url.ParseRequestURI(host)
-	if err != nil {
-		return nil, err
-	}
-	if len(topics) == 0 {
-		return nil, errors.New("no topics provided")
-	}
-
-	return &EventStream{
-		ctx:        ctx,
-		httpClient: httpClient,
-		host:       host,
-		topics:     topics,
-	}, nil
-}
-
-func (h *EventStream) Subscribe(eventsChannel chan<- *Event) {
-	allTopics := strings.Join(h.topics, ",")
-	log.WithField("topics", allTopics).Info("Listening to Beacon API events")
-	fullUrl := h.host + "/eth/v1/events?topics=" + allTopics
-	req, err := http.NewRequestWithContext(h.ctx, http.MethodGet, fullUrl, nil)
-	if err != nil {
-		eventsChannel <- &Event{
-			EventType: EventConnectionError,
-			Data:      []byte(errors.Wrap(err, "failed to create HTTP request").Error()),
-		}
-	}
-	req.Header.Set("Accept", api.EventStreamMediaType)
-	req.Header.Set("Connection", api.KeepAlive)
-	resp, err := h.httpClient.Do(req)
-	if err != nil {
-		eventsChannel <- &Event{
-			EventType: EventConnectionError,
-			Data:      []byte(errors.Wrap(err, client.ErrConnectionIssue.Error()).Error()),
-		}
-	}
-
-	defer func() {
-		if closeErr := resp.Body.Close(); closeErr != nil {
-			log.WithError(closeErr).Error("Failed to close events response body")
-		}
-	}()
-	// Create a new scanner to read lines from the response body
-	scanner := bufio.NewScanner(resp.Body)
-
-	var eventType, data string // Variables to store event type and data
-
-	// Iterate over lines of the event stream
-	for scanner.Scan() {
-		select {
-		case <-h.ctx.Done():
-			log.Info("Context canceled, stopping event stream")
-			close(eventsChannel)
-			return
-		default:
-			line := scanner.Text() // TODO(13730): scanner does not handle /r and does not fully adhere to https://html.spec.whatwg.org/multipage/server-sent-events.html#the-eventsource-interface
-			// Handle the event based on your specific format
-			if line == "" {
-				// Empty line indicates the end of an event
-				if eventType != "" && data != "" {
-					// Process the event when both eventType and data are set
-					eventsChannel <- &Event{EventType: eventType, Data: []byte(data)}
-				}
-
-				// Reset eventType and data for the next event
-				eventType, data = "", ""
-				continue
-			}
-			et, ok := strings.CutPrefix(line, "event: ")
-			if ok {
-				// Extract event type from the "event" field
-				eventType = et
-			}
-			d, ok := strings.CutPrefix(line, "data: ")
-			if ok {
-				// Extract data from the "data" field
-				data = d
-			}
-		}
-	}
-
-	if err := scanner.Err(); err != nil {
-		eventsChannel <- &Event{
-			EventType: EventConnectionError,
-			Data:      []byte(errors.Wrap(err, errors.Wrap(client.ErrConnectionIssue, "scanner failed").Error()).Error()),
-		}
-	}
-}
--- a/api/client/event/event_stream_test.go
+++ b/api/client/event/event_stream_test.go
@@ -1,80 +0,0 @@
-package event
-
-import (
-	"context"
-	"fmt"
-	"net/http"
-	"net/http/httptest"
-	"testing"
-	"time"
-
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	log "github.com/sirupsen/logrus"
-)
-
-func TestNewEventStream(t *testing.T) {
-	validURL := "http://localhost:8080"
-	invalidURL := "://invalid"
-	topics := []string{"topic1", "topic2"}
-
-	tests := []struct {
-		name    string
-		host    string
-		topics  []string
-		wantErr bool
-	}{
-		{"Valid input", validURL, topics, false},
-		{"Invalid URL", invalidURL, topics, true},
-		{"No topics", validURL, []string{}, true},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			_, err := NewEventStream(context.Background(), &http.Client{}, tt.host, tt.topics)
-			if (err != nil) != tt.wantErr {
-				t.Errorf("NewEventStream() error = %v, wantErr %v", err, tt.wantErr)
-			}
-		})
-	}
-}
-
-func TestEventStream(t *testing.T) {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/eth/v1/events", func(w http.ResponseWriter, r *http.Request) {
-		flusher, ok := w.(http.Flusher)
-		require.Equal(t, true, ok)
-		for i := 1; i <= 2; i++ {
-			_, err := fmt.Fprintf(w, "event: head\ndata: data%d\n\n", i)
-			require.NoError(t, err)
-			flusher.Flush()                    // Trigger flush to simulate streaming data
-			time.Sleep(100 * time.Millisecond) // Simulate delay between events
-		}
-	})
-	server := httptest.NewServer(mux)
-	defer server.Close()
-
-	topics := []string{"head"}
-	eventsChannel := make(chan *Event, 1)
-	stream, err := NewEventStream(context.Background(), http.DefaultClient, server.URL, topics)
-	require.NoError(t, err)
-	go stream.Subscribe(eventsChannel)
-
-	// Collect events
-	var events []*Event
-
-	for len(events) != 2 {
-		select {
-		case event := <-eventsChannel:
-			log.Info(event)
-			events = append(events, event)
-		}
-	}
-
-	// Assertions to verify the events content
-	expectedData := []string{"data1", "data2"}
-	for i, event := range events {
-		if string(event.Data) != expectedData[i] {
-			t.Errorf("Expected event data %q, got %q", expectedData[i], string(event.Data))
-		}
-	}
-}
--- a/api/client/validator/BUILD.bazel
+++ b/api/client/validator/BUILD.bazel
@@ -3,7 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library")
 go_library(
    name = "go_default_library",
    srcs = ["client.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/client/validator",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/validator",
    visibility = ["//visibility:public"],
    deps = [
        "//api/client:go_default_library",
--- a/api/client/validator/client.go
+++ b/api/client/validator/client.go
@@ -7,8 +7,8 @@ import (
 	"strings"

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

 const (
--- a/api/constants.go
+++ b/api/constants.go
@@ -1,7 +0,0 @@
-package api
-
-const (
-	WebUrlPrefix        = "/v2/validator/"
-	WebApiUrlPrefix     = "/api/v2/validator/"
-	KeymanagerApiPrefix = "/eth/v1"
-)
--- a/api/gateway/BUILD.bazel
+++ b/api/gateway/BUILD.bazel
@@ -8,17 +8,18 @@ go_library(
        "modifiers.go",
        "options.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/api/gateway",
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/gateway",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//validator:__subpackages__",
    ],
    deps = [
-        "//api/server:go_default_library",
+        "//api/gateway/apimiddleware:go_default_library",
        "//runtime:go_default_library",
        "@com_github_gorilla_mux//:go_default_library",
        "@com_github_grpc_ecosystem_grpc_gateway_v2//runtime:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_rs_cors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
        "@org_golang_google_grpc//:go_default_library",
        "@org_golang_google_grpc//connectivity:go_default_library",
@@ -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/v5/api/server"
-	"github.com/prysmaticlabs/prysm/v5/runtime"
+	"github.com/prysmaticlabs/prysm/v4/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/v4/runtime"
+	"github.com/rs/cors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
@@ -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
@@ -10,25 +10,44 @@ import (
 	"testing"

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

 func TestDouble(t *testing.T) {
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -6,7 +6,6 @@ go_library(
        "chain_info.go",
        "chain_info_forkchoice.go",
        "currently_syncing_block.go",
-        "defragment.go",
        "error.go",
        "execution_engine.go",
        "forkchoice_update_execution.go",
@@ -27,10 +26,9 @@ go_library(
        "receive_blob.go",
        "receive_block.go",
        "service.go",
-        "tracked_proposer.go",
        "weak_subjectivity_checks.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain",
+    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//cmd/beacon-chain:__subpackages__",
@@ -51,10 +49,10 @@ go_library(
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/time:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
-        "//beacon-chain/das:go_default_library",
        "//beacon-chain/db:go_default_library",
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/db/filters:go_default_library",
+        "//beacon-chain/db/kv:go_default_library",
        "//beacon-chain/execution:go_default_library",
        "//beacon-chain/forkchoice:go_default_library",
        "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
@@ -101,22 +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",
@@ -125,67 +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
@@ -6,21 +6,19 @@ import (
 	"time"

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

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

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

-// TargetRootForEpoch wraps the corresponding method in forkchoice
-func (s *Service) TargetRootForEpoch(root [32]byte, epoch primitives.Epoch) ([32]byte, error) {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.TargetRootForEpoch(root, epoch)
-}
-
 // Ancestor returns the block root of an ancestry block from the input block root.
 //
 // Spec pseudocode definition:
@@ -556,16 +537,3 @@ func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
 	defer s.cfg.ForkChoiceStore.RUnlock()
 	return s.cfg.ForkChoiceStore.Slot(root)
 }
-
-// inRegularSync queries the initial sync service to
-// determine if the node is in regular sync or is still
-// syncing to the head of the chain.
-func (s *Service) inRegularSync() bool {
-	return s.cfg.SyncChecker.Synced()
-}
-
-// validating returns true if the beacon is tracking some validators that have
-// registered for proposing.
-func (s *Service) validating() bool {
-	return s.cfg.TrackedValidatorsCache.Validating()
-}
--- a/beacon-chain/blockchain/chain_info_forkchoice.go
+++ b/beacon-chain/blockchain/chain_info_forkchoice.go
@@ -3,9 +3,9 @@ package blockchain
 import (
 	"context"

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

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

-// ShouldOverrideFCU returns the corresponding value from forkchoice
-func (s *Service) ShouldOverrideFCU() bool {
-	s.cfg.ForkChoiceStore.RLock()
-	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.ShouldOverrideFCU()
-}
-
 // SetForkChoiceGenesisTime sets the genesis time in Forkchoice
 func (s *Service) SetForkChoiceGenesisTime(timestamp uint64) {
 	s.cfg.ForkChoiceStore.Lock()
--- a/beacon-chain/blockchain/chain_info_norace_test.go
+++ b/beacon-chain/blockchain/chain_info_norace_test.go
@@ -4,14 +4,14 @@ import (
 	"context"
 	"testing"

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

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

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

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

 func TestService_IsOptimisticBeforeBellatrix(t *testing.T) {
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
nisdas	c3773ad796	fix it	2023-11-24 17:16:46 +08:00
nisdas	ce37952217	fix it	2023-11-24 16:37:24 +08:00
nisdas	2119b0ec28	Merge branch 'develop' of https://github.com/prysmaticlabs/geth-sharding into optimizeMVSlice	2023-11-24 16:12:25 +08:00
nisdas	06dcc5396c	Merge branch 'develop' of https://github.com/prysmaticlabs/geth-sharding into optimizeMVSlice	2023-10-21 22:47:17 +08:00
nisdas	06115705ac	fix panics	2023-10-11 23:36:03 +08:00
nisdas	617996fec9	save current progress	2023-10-11 22:54:44 +08:00
@@ -1 +1 @@
 .1.0
 .3.2