Update runner.go

2026-01-11 06:18:05 -05:00 · 2022-07-19 09:38:55 -05:00
2577 changed files with 64699 additions and 100890 deletions
--- a/.bazelrc
+++ b/.bazelrc
@@ -13,6 +13,7 @@ coverage --define=coverage_enabled=1

 # Fix for rules_docker. See: https://github.com/bazelbuild/rules_docker/issues/842
 build --host_force_python=PY2
+test --host_force_python=PY2
 run --host_force_python=PY2

 # Networking is blocked for tests by default, add "requires-network" tag to your test if networking
@@ -21,12 +22,15 @@ build --sandbox_default_allow_network=false

 # Stamp binaries with git information
 build --workspace_status_command=./hack/workspace_status.sh
+build --stamp

 # Prevent PATH changes from rebuilding when switching from IDE to command line.
 build --incompatible_strict_action_env
+test --incompatible_strict_action_env
 run --incompatible_strict_action_env

 build --define blst_disabled=false
+test --define blst_disabled=false
 run --define blst_disabled=false

 build:blst_disabled --define blst_disabled=true
@@ -37,14 +41,13 @@ build:minimal --@io_bazel_rules_go//go/config:tags=minimal

 # Release flags
 build:release --compilation_mode=opt
-build:release --stamp
+build:release --config=llvm

 # LLVM compiler for building C/C++ dependencies.
+build:llvm --crosstool_top=@llvm_toolchain//:toolchain
 build:llvm --define compiler=llvm
 build:llvm --copt -fno-sanitize=vptr,function
 build:llvm --linkopt -fno-sanitize=vptr,function
-# --incompatible_enable_cc_toolchain_resolution not needed after this issue is closed https://github.com/bazelbuild/bazel/issues/7260
-build:llvm --incompatible_enable_cc_toolchain_resolution

 build:asan --copt -fsanitize=address,undefined
 build:asan --copt -fno-omit-frame-pointer
@@ -82,12 +85,6 @@ build:osx_amd64 --config=cross
 build:osx_amd64 --platforms=@io_bazel_rules_go//go/toolchain:darwin_amd64_cgo
 build:osx_amd64 --compiler=osxcross

-# osx_arm64 config for cross compiler toolchain
-build:osx_arm64 --config=cross
-build:osx_arm64 --platforms=@io_bazel_rules_go//go/toolchain:darwin_arm64_cgo
-build:osx_arm64 --compiler=osxcross
-build:osx_arm64 --cpu=aarch64
-
 # windows
 build:windows_amd64 --config=cross
 build:windows_amd64  --platforms=@io_bazel_rules_go//go/toolchain:windows_amd64_cgo
@@ -119,10 +116,6 @@ build:windows_amd64_debug --config=debug
 build:osx_amd64_debug --config=debug
 build:osx_amd64_debug --config=osx_amd64

-# osx_arm64 debug config
-build:osx_arm64_debug --config=debug
-build:osx_arm64_debug --config=osx_arm64
-
 # linux_arm64_debug
 build:linux_arm64_debug --config=linux_arm64
 build:linux_arm64_debug --config=debug
@@ -158,10 +151,6 @@ build:windows_amd64_docker_debug --config=windows_amd64_docker --config=debug
 build:osx_amd64_docker --config=docker-sandbox --config=osx_amd64
 build:osx_amd64_docker_debug --config=osx_amd64_docker --config=debug

-# osx_arm64 docker sandbox build config
-build:osx_arm64_docker --config=docker-sandbox --config=osx_arm64
-build:osx_arm64_docker_debug --config=osx_arm64_docker --config=debug
-
 # linux_arm64 docker sandbox build config
 build:linux_arm64_docker --config=docker-sandbox --config=linux_arm64
 build:linux_arm64_docker_debug --config=linux_arm64_docker --config=debug
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-5.3.0
+5.0.0
--- a/.deepsource.toml
+++ b/.deepsource.toml
@@ -11,7 +11,7 @@ name = "go"
 enabled = true

 [analyzers.meta]
-import_paths = ["github.com/prysmaticlabs/prysm/v3"]
+import_paths = ["github.com/prysmaticlabs/prysm"]

 [[analyzers]]
 name = "test-coverage"
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -5,4 +5,12 @@
 *.bzl @prestonvanloon

 # Anyone on prylabs team can approve dependency updates.
-deps.bzl @prysmaticlabs/core-team
+deps.bzl @prysmaticlabs/core-team
+
+# Radek and Nishant are responsible for changes that can affect the native state feature.
+# See https://www.notion.so/prysmaticlabs/Native-Beacon-State-Redesign-6cc9744b4ec1439bb34fa829b36a35c1
+/beacon-chain/state/fieldtrie/ @rkapka @nisdas @rauljordan
+/beacon-chain/state/v1/ @rkapka @nisdas @rauljordan
+/beacon-chain/state/v2/ @rkapka @nisdas @rauljordan
+/beacon-chain/state/v3/ @rkapka @nisdas @rauljordan
+/beacon-chain/state/state-native/ @rkapka @nisdas @rauljordan
--- a/.github/ISSUE_TEMPLATE/feature_request.md
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -16,12 +16,12 @@ Existing issues often contain information about workarounds, resolution, or prog

 ### Description

-<!-- ✍️ A clear and concise description of the problem or missing capability... --> 
+<!-- ✍️--> A clear and concise description of the problem or missing capability...

 ### Describe the solution you'd like

-<!-- ✍️ If you have a solution in mind, please describe it. --> 
+<!-- ✍️--> If you have a solution in mind, please describe it.

 ### Describe alternatives you've considered

-<!-- ✍️ Have you considered any alternative solutions or workarounds? --> 
+<!-- ✍️--> Have you considered any alternative solutions or workarounds?
--- a/.github/actions/gofmt/Dockerfile
+++ b/.github/actions/gofmt/Dockerfile
@@ -0,0 +1,5 @@
+FROM cytopia/gofmt
+
+COPY entrypoint.sh /entrypoint.sh
+
+ENTRYPOINT ["/entrypoint.sh"]
--- a/.github/actions/gofmt/action.yml
+++ b/.github/actions/gofmt/action.yml
@@ -0,0 +1,12 @@
+name: 'Gofmt checker'
+description: 'Checks that all project files have been properly formatted.'
+inputs:
+  path:
+    description: 'Path to check'
+    required: true
+    default: './'
+runs:
+  using: 'docker'
+  image: 'Dockerfile'
+  args:
+    - ${{ inputs.path }}
--- a/.github/actions/gofmt/entrypoint.sh
+++ b/.github/actions/gofmt/entrypoint.sh
@@ -0,0 +1,15 @@
+#!/bin/sh -l
+set -e
+
+cd $GITHUB_WORKSPACE
+
+# Check if any files are not formatted.
+nonformatted="$(gofmt -l $1 2>&1)"
+
+# Return if `go fmt` passes.
+[ -z "$nonformatted" ] && exit 0
+
+# Notify of issues with formatting.
+echo "Following files need to be properly formatted:"
+echo "$nonformatted"
+exit 1
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -18,6 +18,18 @@ jobs:
        id: gomodtidy
        uses: ./.github/actions/gomodtidy

+      - name: Gofmt checker
+        id: gofmt
+        uses: ./.github/actions/gofmt
+        with:
+          path: ./
+
+      - name: GoImports checker
+        id: goimports
+        uses: Jerome1337/goimports-action@v1.0.2
+        with:
+          goimports-path: ./
+
  gosec:
    name: Gosec scan
    runs-on: ubuntu-latest
@@ -26,14 +38,14 @@ jobs:
    steps:
      - name: Checkout
        uses: actions/checkout@v2
-      - name: Set up Go 1.19
+      - name: Set up Go 1.18
        uses: actions/setup-go@v3
        with:
-          go-version: 1.19
+          go-version: 1.18
      - 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@v2.12.0
+          go install github.com/securego/gosec/v2/cmd/gosec@latest
          gosec -exclude=G307 -exclude-dir=crypto/bls/herumi ./...

  lint:
@@ -43,17 +55,17 @@ jobs:
      - name: Checkout
        uses: actions/checkout@v2

-      - name: Set up Go 1.19
+      - name: Set up Go 1.18
        uses: actions/setup-go@v3
        with:
-          go-version: 1.19
+          go-version: 1.18
          id: go

      - name: Golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v2
        with:
-          version: v1.50.1
-          args: --config=.golangci.yml --out-${NO_FUTURE}format colored-line-number
+          version: v1.45.2
+          skip-go-installation: true

  build:
    name: Build
@@ -62,7 +74,7 @@ jobs:
      - name: Set up Go 1.x
        uses: actions/setup-go@v2
        with:
-          go-version: 1.19
+          go-version: 1.18
        id: go

      - name: Check out code into the Go module directory
--- a/.gitignore
+++ b/.gitignore
@@ -38,6 +38,3 @@ metaData

 # execution API authentication
 jwt.hex
-
-# manual testing
-tmp
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -6,14 +6,12 @@ run:
    - proto
    - tools/analyzers
  timeout: 10m
-  go: '1.19'
+  go: '1.18'

 linters:
  disable-all: true
  enable:
-    - gofmt
-    - goimports
-    - unused
+    - deadcode
    - errcheck
    - gosimple
    - gocognit
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -12,7 +12,7 @@ exports_files([
    "LICENSE.md",
 ])

-# gazelle:prefix github.com/prysmaticlabs/prysm/v3
+# gazelle:prefix github.com/prysmaticlabs/prysm
 # 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
@@ -122,7 +122,6 @@ nogo(
        "//tools/analyzers/gocognit:go_default_library",
        "//tools/analyzers/ineffassign:go_default_library",
        "//tools/analyzers/interfacechecker:go_default_library",
-        "//tools/analyzers/logruswitherror:go_default_library",
        "//tools/analyzers/maligned:go_default_library",
        "//tools/analyzers/nop:go_default_library",
        "//tools/analyzers/properpermissions:go_default_library",
--- a/README.md
+++ b/README.md
@@ -2,10 +2,9 @@

 [![Build status](https://badge.buildkite.com/b555891daf3614bae4284dcf365b2340cefc0089839526f096.svg?branch=master)](https://buildkite.com/prysmatic-labs/prysm)
 [![Go Report Card](https://goreportcard.com/badge/github.com/prysmaticlabs/prysm)](https://goreportcard.com/report/github.com/prysmaticlabs/prysm)
-[![Consensus_Spec_Version 1.2.0](https://img.shields.io/badge/Consensus%20Spec%20Version-v1.2.0-blue.svg)](https://github.com/ethereum/consensus-specs/tree/v1.2.0)
-[![Execution_API_Version 1.0.0-beta.1](https://img.shields.io/badge/Execution%20API%20Version-v1.0.0.beta.1-blue.svg)](https://github.com/ethereum/execution-apis/tree/v1.0.0-beta.1/src/engine)
+[![Consensus_Spec_Version 1.2.0-rc.1](https://img.shields.io/badge/Consensus%20Spec%20Version-v1.2.0.rc.1-blue.svg)](https://github.com/ethereum/consensus-specs/tree/v1.2.0-rc.1)
+[![Execution_API_Version 1.0.0-alpha.9](https://img.shields.io/badge/Execution%20API%20Version-v1.0.0.alpha.9-blue.svg)](https://github.com/ethereum/execution-apis/tree/v1.0.0-alpha.9/src/engine)
 [![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/CTYGPUJ)
-[![GitPOAP Badge](https://public-api.gitpoap.io/v1/repo/prysmaticlabs/prysm/badge)](https://www.gitpoap.io/gh/prysmaticlabs/prysm)

 This is the core repository for Prysm, a [Golang](https://golang.org/) implementation of the [Ethereum Consensus](https://ethereum.org/en/eth2/) specification, developed by [Prysmatic Labs](https://prysmaticlabs.com). See the [Changelog](https://github.com/prysmaticlabs/prysm/releases) for details of the latest releases and upcoming breaking changes.

--- a/63
+++ b/63
@@ -15,9 +15,9 @@ http_archive(

 http_archive(
    name = "com_grail_bazel_toolchain",
-    sha256 = "b210fc8e58782ef171f428bfc850ed7179bdd805543ebd1aa144b9c93489134f",
-    strip_prefix = "bazel-toolchain-83e69ba9e4b4fdad0d1d057fcb87addf77c281c9",
-    urls = ["https://github.com/grailbio/bazel-toolchain/archive/83e69ba9e4b4fdad0d1d057fcb87addf77c281c9.tar.gz"],
+    sha256 = "040b9d00b8a03e8a28e38159ad0f2d0e0de625d93f453a9f226971a8c47e757b",
+    strip_prefix = "bazel-toolchain-5f82830f9d6a1941c3eb29683c1864ccf2862454",
+    urls = ["https://github.com/grailbio/bazel-toolchain/archive/5f82830f9d6a1941c3eb29683c1864ccf2862454.tar.gz"],
 )

 load("@com_grail_bazel_toolchain//toolchain:deps.bzl", "bazel_toolchain_dependencies")
@@ -28,7 +28,7 @@ load("@com_grail_bazel_toolchain//toolchain:rules.bzl", "llvm_toolchain")

 llvm_toolchain(
    name = "llvm_toolchain",
-    llvm_version = "13.0.1",
+    llvm_version = "10.0.0",
 )

 load("@llvm_toolchain//:toolchains.bzl", "llvm_register_toolchains")
@@ -88,10 +88,10 @@ http_archive(
        # Expose internals of go_test for custom build transitions.
        "//third_party:io_bazel_rules_go_test.patch",
    ],
-    sha256 = "ae013bf35bd23234d1dea46b079f1e05ba74ac0321423830119d3e787ec73483",
+    sha256 = "f2dcd210c7095febe54b804bb1cd3a58fe8435a909db2ec04e31542631cf715c",
    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.36.0/rules_go-v0.36.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.36.0/rules_go-v0.36.0.zip",
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.31.0/rules_go-v0.31.0.zip",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.31.0/rules_go-v0.31.0.zip",
    ],
 )

@@ -110,6 +110,13 @@ git_repository(
    # gazelle args: -go_prefix github.com/gogo/protobuf -proto legacy
 )

+http_archive(
+    name = "fuzzit_linux",
+    build_file_content = "exports_files([\"fuzzit\"])",
+    sha256 = "9ca76ac1c22d9360936006efddf992977ebf8e4788ded8e5f9d511285c9ac774",
+    urls = ["https://github.com/fuzzitdev/fuzzit/releases/download/v2.4.76/fuzzit_Linux_x86_64.zip"],
+)
+
 load(
    "@io_bazel_rules_docker//repositories:repositories.bzl",
    container_repositories = "repositories",
@@ -157,15 +164,35 @@ container_pull(
    repository = "pinglamb/alpine-glibc",
 )

+container_pull(
+    name = "fuzzit_base",
+    digest = "sha256:24a39a4360b07b8f0121eb55674a2e757ab09f0baff5569332fefd227ee4338f",
+    registry = "gcr.io",
+    repository = "fuzzit-public/stretch-llvm8",
+)
+
 load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")

 go_rules_dependencies()

 go_register_toolchains(
-    go_version = "1.19.4",
+    go_version = "1.18.1",
    nogo = "@//:nogo",
 )

+http_archive(
+    name = "prysm_testnet_site",
+    build_file_content = """
+proto_library(
+  name = "faucet_proto",
+  srcs = ["src/proto/faucet.proto"],
+  visibility = ["//visibility:public"],
+)""",
+    sha256 = "29742136ff9faf47343073c4569a7cf21b8ed138f726929e09e3c38ab83544f7",
+    strip_prefix = "prysm-testnet-site-5c711600f0a77fc553b18cf37b880eaffef4afdb",
+    url = "https://github.com/prestonvanloon/prysm-testnet-site/archive/5c711600f0a77fc553b18cf37b880eaffef4afdb.tar.gz",
+)
+
 http_archive(
    name = "io_kubernetes_build",
    sha256 = "b84fbd1173acee9d02a7d3698ad269fdf4f7aa081e9cecd40e012ad0ad8cfa2a",
@@ -188,7 +215,7 @@ filegroup(
    url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/b8413ca42dc92308019d0d4db52c87e9e125c4e9.tar.gz",
 )

-consensus_spec_version = "v1.3.0-rc.1"
+consensus_spec_version = "v1.2.0-rc.1"

 bls_test_version = "v0.1.1"

@@ -204,7 +231,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "3d6fadb64674eb64a84fae6c2efa9949231ea91e7cb74ada9214097323e86569",
+    sha256 = "9c93f87378aaa6d6fe1c67b396eac2aacc9594af2a83f028cb99c95dea5b81df",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

@@ -220,7 +247,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "54ffbcab1e77316a280e6f5a64c6ed62351e8f5678e6fa49340e49b9b5575e8e",
+    sha256 = "52f2c52415228cee8a4de5a09abff785f439a77dfef8f03e834e4e16857673c1",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

@@ -236,7 +263,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "bb06d30ca533dc97d45f2367916ba9ff1b5af52f08a9d8c33bb7b1a61254094e",
+    sha256 = "022dcc0d6de7dd27b337a0d1b945077eaf5ee47000700395a693fc25e12f96df",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

@@ -251,7 +278,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "9d22246c00ec3907ef8dc3ddccdfe6f7153ce46df73deee0a0176fe7e4aa1126",
+    sha256 = "0a9c110305cbd6ebbe0d942f0f33e6ce22dd484ce4ceed277bf185a091941cde",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -282,9 +309,9 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "82b01a48b143fe0f2fb7fb5f5dd385c1f934335a12d7954f08b1d45d77427b5e",
-    strip_prefix = "eth2-networks-674f7a1d01d9c18345456eab76e3871b3df2126b",
-    url = "https://github.com/eth-clients/eth2-networks/archive/674f7a1d01d9c18345456eab76e3871b3df2126b.tar.gz",
+    sha256 = "4e8a18b21d056c4032605621b1a6632198eabab57cb90c61e273f344c287f1b2",
+    strip_prefix = "eth2-networks-791a5369c5981e829698b17fbcdcdacbdaba97c8",
+    url = "https://github.com/eth-clients/eth2-networks/archive/791a5369c5981e829698b17fbcdcdacbdaba97c8.tar.gz",
 )

 http_archive(
@@ -315,9 +342,9 @@ filegroup(
    visibility = ["//visibility:public"],
 )
 """,
-    sha256 = "b2226874526805d64c29e5053fa28e511b57c0860585d6d59777ee81ff4859ca",
+    sha256 = "98013b40922e54a64996da49b939e0a88fe2456f68eedc5aee4ceba0f8623f71",
    urls = [
-        "https://github.com/prysmaticlabs/prysm-web-ui/releases/download/v2.0.2/prysm-web-ui.tar.gz",
+        "https://github.com/prysmaticlabs/prysm-web-ui/releases/download/v2.0.0/prysm-web-ui.tar.gz",
    ],
 )

--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -8,7 +8,7 @@ go_library(
        "doc.go",
        "errors.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v3/api/client/beacon",
+    importpath = "github.com/prysmaticlabs/prysm/api/client/beacon",
    visibility = ["//visibility:public"],
    deps = [
        "//beacon-chain/core/helpers:go_default_library",
@@ -40,9 +40,8 @@ go_test(
    deps = [
        "//beacon-chain/state:go_default_library",
        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
        "//consensus-types/primitives:go_default_library",
+        "//consensus-types/wrapper:go_default_library",
        "//encoding/ssz/detect:go_default_library",
        "//network/forks:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
--- a/api/client/beacon/checkpoint.go
+++ b/api/client/beacon/checkpoint.go
@@ -6,14 +6,14 @@ import (
 	"path"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v3/io/file"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/ssz/detect"
+	"github.com/prysmaticlabs/prysm/io/file"
+	"github.com/prysmaticlabs/prysm/runtime/version"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/mod/semver"
 )
@@ -21,13 +21,14 @@ import (
 // OriginData represents the BeaconState and SignedBeaconBlock necessary to start an empty Beacon Node
 // using Checkpoint Sync.
 type OriginData struct {
-	sb []byte
-	bb []byte
-	st state.BeaconState
-	b  interfaces.SignedBeaconBlock
-	vu *detect.VersionedUnmarshaler
-	br [32]byte
-	sr [32]byte
+	wsd *WeakSubjectivityData
+	sb  []byte
+	bb  []byte
+	st  state.BeaconState
+	b   interfaces.SignedBeaconBlock
+	vu  *detect.VersionedUnmarshaler
+	br  [32]byte
+	sr  [32]byte
 }

 // SaveBlock saves the downloaded block to a unique file in the given path.
@@ -74,9 +75,6 @@ func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, er
 	if err != nil {
 		return nil, errors.Wrap(err, "error unmarshaling finalized state to correct version")
 	}
-	if s.Slot() != s.LatestBlockHeader().Slot {
-		return nil, fmt.Errorf("finalized state slot does not match latest block header slot %d != %d", s.Slot(), s.LatestBlockHeader().Slot)
-	}

 	sr, err := s.HashTreeRoot(ctx)
 	if err != nil {
--- a/api/client/beacon/checkpoint_test.go
+++ b/api/client/beacon/checkpoint_test.go
@@ -10,21 +10,21 @@ import (
 	"net/url"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	blocktest "github.com/prysmaticlabs/prysm/v3/consensus-types/blocks/testing"
-	"github.com/prysmaticlabs/prysm/v3/network/forks"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"

-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/network/forks"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
+
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/ssz/detect"
+	"github.com/prysmaticlabs/prysm/runtime/version"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 type testRT struct {
@@ -134,14 +134,10 @@ func TestDownloadWeakSubjectivityCheckpoint(t *testing.T) {
 	require.NoError(t, wst.SetFork(fork))

 	// set up checkpoint block
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockParentRoot(b, cfg.ZeroHash)
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockSlot(b, wSlot)
-	require.NoError(t, err)
-	b, err = blocktest.SetProposerIndex(b, 0)
-	require.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
+	require.NoError(t, wrapper.SetBlockParentRoot(b, cfg.ZeroHash))
+	require.NoError(t, wrapper.SetBlockSlot(b, wSlot))
+	require.NoError(t, wrapper.SetProposerIndex(b, 0))

 	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
 	header, err := b.Header()
@@ -155,8 +151,7 @@ func TestDownloadWeakSubjectivityCheckpoint(t *testing.T) {
 	wRoot, err := wst.HashTreeRoot(ctx)
 	require.NoError(t, err)

-	b, err = blocktest.SetBlockStateRoot(b, wRoot)
-	require.NoError(t, err)
+	require.NoError(t, wrapper.SetBlockStateRoot(b, wRoot))
 	serBlock, err := b.MarshalSSZ()
 	require.NoError(t, err)
 	bRoot, err := b.Block().HashTreeRoot()
@@ -235,14 +230,10 @@ func TestDownloadBackwardsCompatibleCombined(t *testing.T) {
 	require.NoError(t, wst.SetFork(fork))

 	// set up checkpoint block
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockParentRoot(b, cfg.ZeroHash)
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockSlot(b, wSlot)
-	require.NoError(t, err)
-	b, err = blocktest.SetProposerIndex(b, 0)
-	require.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
+	require.NoError(t, wrapper.SetBlockParentRoot(b, cfg.ZeroHash))
+	require.NoError(t, wrapper.SetBlockSlot(b, wSlot))
+	require.NoError(t, wrapper.SetProposerIndex(b, 0))

 	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
 	header, err := b.Header()
@@ -256,8 +247,7 @@ func TestDownloadBackwardsCompatibleCombined(t *testing.T) {
 	wRoot, err := wst.HashTreeRoot(ctx)
 	require.NoError(t, err)

-	b, err = blocktest.SetBlockStateRoot(b, wRoot)
-	require.NoError(t, err)
+	require.NoError(t, wrapper.SetBlockStateRoot(b, wRoot))
 	serBlock, err := b.MarshalSSZ()
 	require.NoError(t, err)
 	bRoot, err := b.Block().HashTreeRoot()
@@ -418,17 +408,12 @@ func TestDownloadFinalizedData(t *testing.T) {
 	require.NoError(t, err)
 	fork, err := forkForEpoch(cfg, epoch)
 	require.NoError(t, st.SetFork(fork))
-	require.NoError(t, st.SetSlot(slot))

 	// set up checkpoint block
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockParentRoot(b, cfg.ZeroHash)
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockSlot(b, slot)
-	require.NoError(t, err)
-	b, err = blocktest.SetProposerIndex(b, 0)
-	require.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
+	require.NoError(t, wrapper.SetBlockParentRoot(b, cfg.ZeroHash))
+	require.NoError(t, wrapper.SetBlockSlot(b, slot))
+	require.NoError(t, wrapper.SetProposerIndex(b, 0))

 	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
 	header, err := b.Header()
@@ -442,8 +427,7 @@ func TestDownloadFinalizedData(t *testing.T) {
 	sr, err := st.HashTreeRoot(ctx)
 	require.NoError(t, err)

-	b, err = blocktest.SetBlockStateRoot(b, sr)
-	require.NoError(t, err)
+	require.NoError(t, wrapper.SetBlockStateRoot(b, sr))
 	mb, err := b.MarshalSSZ()
 	require.NoError(t, err)
 	br, err := b.Block().HashTreeRoot()
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -16,14 +16,14 @@ import (
 	"text/template"
 	"time"

-	"github.com/prysmaticlabs/prysm/v3/network/forks"
+	"github.com/prysmaticlabs/prysm/network/forks"

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/rpc/apimiddleware"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/beacon-chain/rpc/apimiddleware"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	log "github.com/sirupsen/logrus"
 )

@@ -95,6 +95,8 @@ func WithTimeout(timeout time.Duration) ClientOpt {
 // Client provides a collection of helper methods for calling the Eth Beacon Node API endpoints.
 type Client struct {
 	hc      *http.Client
+	host    string
+	scheme  string
 	baseURL *url.URL
 }

--- a/api/client/beacon/client_test.go
+++ b/api/client/beacon/client_test.go
@@ -4,7 +4,7 @@ import (
 	"net/url"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func TestParseNodeVersion(t *testing.T) {
--- a/api/client/beacon/doc.go
+++ b/api/client/beacon/doc.go
@@ -1,5 +1,6 @@
 /*
 Package beacon provides a client for interacting with the standard Eth Beacon Node API.
 Interactive swagger documentation for the API is available here: https://ethereum.github.io/beacon-APIs/
+
 */
 package beacon
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -7,14 +7,12 @@ go_library(
        "errors.go",
        "types.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v3/api/client/builder",
+    importpath = "github.com/prysmaticlabs/prysm/api/client/builder",
    visibility = ["//visibility:public"],
    deps = [
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil: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",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -13,12 +13,10 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/monitoring/tracing"
-	"github.com/prysmaticlabs/prysm/v3/network"
-	"github.com/prysmaticlabs/prysm/v3/network/authorization"
-	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/monitoring/tracing"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	log "github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -32,11 +30,17 @@ const (

 var errMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
 var errMalformedRequest = errors.New("required request data are missing")
-var submitBlindedBlockTimeout = 3 * time.Second

 // ClientOpt is a functional option for the Client type (http.Client wrapper)
 type ClientOpt func(*Client)

+// WithTimeout sets the .Timeout attribute of the wrapped http.Client.
+func WithTimeout(timeout time.Duration) ClientOpt {
+	return func(c *Client) {
+		c.hc.Timeout = timeout
+	}
+}
+
 type observer interface {
 	observe(r *http.Request) error
 }
@@ -79,15 +83,6 @@ func (*requestLogger) observe(r *http.Request) (e error) {

 var _ observer = &requestLogger{}

-// BuilderClient provides a collection of helper methods for calling Builder API endpoints.
-type BuilderClient interface {
-	NodeURL() string
-	GetHeader(ctx context.Context, slot types.Slot, parentHash [32]byte, pubkey [48]byte) (*ethpb.SignedBuilderBid, error)
-	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb *ethpb.SignedBlindedBeaconBlockBellatrix) (*v1.ExecutionPayload, error)
-	Status(ctx context.Context) error
-}
-
 // Client provides a collection of helper methods for calling Builder API endpoints.
 type Client struct {
 	hc      *http.Client
@@ -99,8 +94,7 @@ type Client struct {
 // `host` is the base host + port used to construct request urls. This value can be
 // a URL string, or NewClient will assume an http endpoint if just `host:port` is used.
 func NewClient(host string, opts ...ClientOpt) (*Client, error) {
-	endpoint := covertEndPoint(host)
-	u, err := urlForHost(endpoint.Url)
+	u, err := urlForHost(host)
 	if err != nil {
 		return nil, err
 	}
@@ -254,11 +248,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb *ethpb.SignedBlinded
 	if err != nil {
 		return nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockBellatrix value body in SubmitBlindedBlock")
 	}
-
-	ctx, cancel := context.WithTimeout(ctx, submitBlindedBlockTimeout)
-	defer cancel()
 	rb, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body))
-
 	if err != nil {
 		return nil, errors.Wrap(err, "error posting the SignedBlindedBeaconBlockBellatrix to the builder api")
 	}
@@ -279,7 +269,6 @@ func (c *Client) Status(ctx context.Context) error {

 func non200Err(response *http.Response) error {
 	bodyBytes, err := io.ReadAll(response.Body)
-	var errMessage ErrorMessage
 	var body string
 	if err != nil {
 		body = "(Unable to read response body.)"
@@ -288,38 +277,9 @@ func non200Err(response *http.Response) error {
 	}
 	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
-	case 204:
-		log.WithError(ErrNoContent).Debug(msg)
-		return ErrNoContent
-	case 400:
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
-		log.WithError(ErrBadRequest).Debug(msg)
-		return errors.Wrap(ErrBadRequest, errMessage.Message)
 	case 404:
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
-		log.WithError(ErrNotFound).Debug(msg)
-		return errors.Wrap(ErrNotFound, errMessage.Message)
-	case 500:
-		if jsonErr := json.Unmarshal(bodyBytes, &errMessage); jsonErr != nil {
-			return errors.Wrap(jsonErr, "unable to read response body")
-		}
-		log.WithError(ErrNotOK).Debug(msg)
-		return errors.Wrap(ErrNotOK, errMessage.Message)
+		return errors.Wrap(ErrNotFound, msg)
 	default:
-		log.WithError(ErrNotOK).Debug(msg)
-		return errors.Wrap(ErrNotOK, fmt.Sprintf("unsupported error code: %d", response.StatusCode))
+		return errors.Wrap(ErrNotOK, msg)
 	}
 }
-
-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
@@ -3,7 +3,6 @@ package builder
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -12,12 +11,12 @@ import (
 	"testing"

 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 type roundtrip func(*http.Request) (*http.Response, error)
@@ -59,15 +58,9 @@ func TestClient_Status(t *testing.T) {
 				require.NoError(t, r.Body.Close())
 			}()
 			require.Equal(t, statusPath, r.URL.Path)
-			message := ErrorMessage{
-				Code:    500,
-				Message: "Internal server error",
-			}
-			resp, err := json.Marshal(message)
-			require.NoError(t, err)
 			return &http.Response{
 				StatusCode: http.StatusInternalServerError,
-				Body:       io.NopCloser(bytes.NewBuffer(resp)),
+				Body:       io.NopCloser(bytes.NewBuffer(nil)),
 				Request:    r.Clone(ctx),
 			}, nil
 		}),
@@ -81,7 +74,7 @@ func TestClient_Status(t *testing.T) {

 func TestClient_RegisterValidator(t *testing.T) {
 	ctx := context.Background()
-	expectedBody := `[{"message":{"fee_recipient":"0x0000000000000000000000000000000000000000","gas_limit":"23","timestamp":"42","pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}]`
+	expectedBody := `[{"message":{"fee_recipient":"0x0000000000000000000000000000000000000000","gas_limit":"23","timestamp":"42","pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"}}]`
 	expectedPath := "/eth/v1/builder/validators"
 	hc := &http.Client{
 		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -111,7 +104,6 @@ func TestClient_RegisterValidator(t *testing.T) {
 			Timestamp:    42,
 			Pubkey:       ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
 		},
-		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
 	}
 	require.NoError(t, c.RegisterValidator(ctx, []*eth.SignedValidatorRegistrationV1{reg}))
 }
@@ -122,15 +114,9 @@ func TestClient_GetHeader(t *testing.T) {
 	hc := &http.Client{
 		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 			require.Equal(t, expectedPath, r.URL.Path)
-			message := ErrorMessage{
-				Code:    500,
-				Message: "Internal server error",
-			}
-			resp, err := json.Marshal(message)
-			require.NoError(t, err)
 			return &http.Response{
 				StatusCode: http.StatusInternalServerError,
-				Body:       io.NopCloser(bytes.NewBuffer(resp)),
+				Body:       io.NopCloser(bytes.NewBuffer(nil)),
 				Request:    r.Clone(ctx),
 			}, nil
 		}),
@@ -145,23 +131,6 @@ func TestClient_GetHeader(t *testing.T) {
 	_, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
 	require.ErrorIs(t, err, ErrNotOK)

-	hc = &http.Client{
-		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
-			require.Equal(t, expectedPath, r.URL.Path)
-			return &http.Response{
-				StatusCode: http.StatusNoContent,
-				Body:       io.NopCloser(bytes.NewBuffer([]byte("No header is available."))),
-				Request:    r.Clone(ctx),
-			}, nil
-		}),
-	}
-	c = &Client{
-		hc:      hc,
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
-	_, err = c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
-	require.ErrorIs(t, err, ErrNoContent)
-
 	hc = &http.Client{
 		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
 			require.Equal(t, expectedPath, r.URL.Path)
@@ -183,8 +152,7 @@ func TestClient_GetHeader(t *testing.T) {
 	expectedTxRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
 	require.Equal(t, true, bytes.Equal(expectedTxRoot, h.Message.Header.TransactionsRoot))
 	require.Equal(t, uint64(1), h.Message.Header.GasUsed)
-	value, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
+	value := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
 	require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", h.Message.Value))
 }

@@ -208,8 +176,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 	ep, err := c.SubmitBlindedBlock(ctx, sbbb)
 	require.NoError(t, err)
 	require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash))
-	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
 	require.Equal(t, fmt.Sprintf("%#x", bfpg.SSZBytes()), fmt.Sprintf("%#x", ep.BaseFeePerGas))
 	require.Equal(t, uint64(1), ep.GasLimit)
 }
--- a/api/client/builder/errors.go
+++ b/api/client/builder/errors.go
@@ -4,14 +4,7 @@ import "github.com/pkg/errors"

 // ErrNotOK is used to indicate when an HTTP request to the Beacon Node API failed with any non-2xx response code.
 // More specific errors may be returned, but an error in reaction to a non-2xx response will always wrap ErrNotOK.
-var ErrNotOK = errors.New("did not receive 200 response from API")
+var ErrNotOK = errors.New("did not receive 2xx response from API")

 // ErrNotFound specifically means that a '404 - NOT FOUND' response was received from the API.
 var ErrNotFound = errors.Wrap(ErrNotOK, "recv 404 NotFound response from API")
-
-// ErrBadRequest specifically means that a '400 - BAD REQUEST' response was received from the API.
-var ErrBadRequest = errors.Wrap(ErrNotOK, "recv 400 BadRequest response from API")
-
-// ErrNoContent specifically means that a '204 - No Content' response was received from the API.
-// Typically, a 204 is a success but in this case for the Header API means No header is available
-var ErrNoContent = errors.New("recv 204 no content response from API, No header is available")
--- a/api/client/builder/testing/BUILD.bazel
+++ b/api/client/builder/testing/BUILD.bazel
@@ -1,14 +0,0 @@
-load("@prysm//tools/go:def.bzl", "go_library")
-
-go_library(
-    name = "go_default_library",
-    srcs = ["mock.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v3/api/client/builder/testing",
-    visibility = ["//visibility:public"],
-    deps = [
-        "//consensus-types/primitives:go_default_library",
-        "//encoding/bytesutil:go_default_library",
-        "//proto/engine/v1:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-    ],
-)
--- a/api/client/builder/testing/mock.go
+++ b/api/client/builder/testing/mock.go
@@ -1,49 +0,0 @@
-package testing
-
-import (
-	"context"
-
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-)
-
-// MockClient is a mock implementation of BuilderClient.
-type MockClient struct {
-	RegisteredVals map[[48]byte]bool
-}
-
-// NewClient creates a new, correctly initialized mock.
-func NewClient() MockClient {
-	return MockClient{RegisteredVals: map[[48]byte]bool{}}
-}
-
-// NodeURL --
-func (MockClient) NodeURL() string {
-	return ""
-}
-
-// GetHeader --
-func (MockClient) GetHeader(_ context.Context, _ types.Slot, _ [32]byte, _ [48]byte) (*ethpb.SignedBuilderBid, error) {
-	return nil, nil
-}
-
-// RegisterValidator --
-func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error {
-	for _, r := range svr {
-		b := bytesutil.ToBytes48(r.Message.Pubkey)
-		m.RegisteredVals[b] = true
-	}
-	return nil
-}
-
-// SubmitBlindedBlock --
-func (MockClient) SubmitBlindedBlock(_ context.Context, _ *ethpb.SignedBlindedBeaconBlockBellatrix) (*v1.ExecutionPayload, error) {
-	return nil, nil
-}
-
-// Status --
-func (MockClient) Status(_ context.Context) error {
-	return nil
-}
--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
@@ -8,9 +8,9 @@ import (

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 )

 type SignedValidatorRegistration struct {
@@ -23,8 +23,8 @@ type ValidatorRegistration struct {

 func (r *SignedValidatorRegistration) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Message   *ValidatorRegistration `json:"message"`
-		Signature hexutil.Bytes          `json:"signature"`
+		Message   *ValidatorRegistration `json:"message,omitempty"`
+		Signature hexutil.Bytes          `json:"signature,omitempty"`
 	}{
 		Message:   &ValidatorRegistration{r.Message},
 		Signature: r.SignedValidatorRegistrationV1.Signature,
@@ -36,8 +36,8 @@ func (r *SignedValidatorRegistration) UnmarshalJSON(b []byte) error {
 		r.SignedValidatorRegistrationV1 = &eth.SignedValidatorRegistrationV1{}
 	}
 	o := struct {
-		Message   *ValidatorRegistration `json:"message"`
-		Signature hexutil.Bytes          `json:"signature"`
+		Message   *ValidatorRegistration `json:"message,omitempty"`
+		Signature hexutil.Bytes          `json:"signature,omitempty"`
 	}{}
 	if err := json.Unmarshal(b, &o); err != nil {
 		return err
@@ -49,10 +49,10 @@ func (r *SignedValidatorRegistration) UnmarshalJSON(b []byte) error {

 func (r *ValidatorRegistration) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		FeeRecipient hexutil.Bytes `json:"fee_recipient"`
-		GasLimit     string        `json:"gas_limit"`
-		Timestamp    string        `json:"timestamp"`
-		Pubkey       hexutil.Bytes `json:"pubkey"`
+		FeeRecipient hexutil.Bytes `json:"fee_recipient,omitempty"`
+		GasLimit     string        `json:"gas_limit,omitempty"`
+		Timestamp    string        `json:"timestamp,omitempty"`
+		Pubkey       hexutil.Bytes `json:"pubkey,omitempty"`
 	}{
 		FeeRecipient: r.FeeRecipient,
 		GasLimit:     fmt.Sprintf("%d", r.GasLimit),
@@ -66,10 +66,10 @@ func (r *ValidatorRegistration) UnmarshalJSON(b []byte) error {
 		r.ValidatorRegistrationV1 = &eth.ValidatorRegistrationV1{}
 	}
 	o := struct {
-		FeeRecipient hexutil.Bytes `json:"fee_recipient"`
-		GasLimit     string        `json:"gas_limit"`
-		Timestamp    string        `json:"timestamp"`
-		Pubkey       hexutil.Bytes `json:"pubkey"`
+		FeeRecipient hexutil.Bytes `json:"fee_recipient,omitempty"`
+		GasLimit     string        `json:"gas_limit,omitempty"`
+		Timestamp    string        `json:"timestamp,omitempty"`
+		Pubkey       hexutil.Bytes `json:"pubkey,omitempty"`
 	}{}
 	if err := json.Unmarshal(b, &o); err != nil {
 		return err
@@ -88,43 +88,29 @@ func (r *ValidatorRegistration) UnmarshalJSON(b []byte) error {
 	return nil
 }

-var errInvalidUint256 = errors.New("invalid Uint256")
-var errDecodeUint256 = errors.New("unable to decode into Uint256")
-
 type Uint256 struct {
 	*big.Int
 }

-func isValidUint256(bi *big.Int) bool {
-	return bi.Cmp(big.NewInt(0)) >= 0 && bi.BitLen() <= 256
-}
-
-func stringToUint256(s string) (Uint256, error) {
+func stringToUint256(s string) Uint256 {
 	bi := new(big.Int)
-	_, ok := bi.SetString(s, 10)
-	if !ok || !isValidUint256(bi) {
-		return Uint256{}, errors.Wrapf(errDecodeUint256, "value=%s", s)
-	}
-	return Uint256{Int: bi}, nil
+	bi.SetString(s, 10)
+	return Uint256{Int: bi}
 }

 // sszBytesToUint256 creates a Uint256 from a ssz-style (little-endian byte slice) representation.
-func sszBytesToUint256(b []byte) (Uint256, error) {
-	bi := bytesutil.LittleEndianBytesToBigInt(b)
-	if !isValidUint256(bi) {
-		return Uint256{}, errors.Wrapf(errDecodeUint256, "value=%s", b)
-	}
-	return Uint256{Int: bi}, nil
+func sszBytesToUint256(b []byte) Uint256 {
+	bi := new(big.Int)
+	return Uint256{Int: bi.SetBytes(bytesutil.ReverseByteOrder(b))}
 }

 // SSZBytes creates an ssz-style (little-endian byte slice) representation of the Uint256
 func (s Uint256) SSZBytes() []byte {
-	if !isValidUint256(s.Int) {
-		return []byte{}
-	}
 	return bytesutil.PadTo(bytesutil.ReverseByteOrder(s.Int.Bytes()), 32)
 }

+var errUnmarshalUint256Failed = errors.New("unable to UnmarshalText into a Uint256 value")
+
 func (s *Uint256) UnmarshalJSON(t []byte) error {
 	start := 0
 	end := len(t)
@@ -143,10 +129,7 @@ func (s *Uint256) UnmarshalText(t []byte) error {
 	}
 	z, ok := s.SetString(string(t), 10)
 	if !ok {
-		return errors.Wrapf(errDecodeUint256, "value=%s", t)
-	}
-	if !isValidUint256(z) {
-		return errors.Wrapf(errDecodeUint256, "value=%s", t)
+		return errors.Wrapf(errUnmarshalUint256Failed, "value=%s", string(t))
 	}
 	s.Int = z
 	return nil
@@ -163,9 +146,6 @@ func (s Uint256) MarshalJSON() ([]byte, error) {
 }

 func (s Uint256) MarshalText() ([]byte, error) {
-	if !isValidUint256(s.Int) {
-		return nil, errors.Wrapf(errInvalidUint256, "value=%s", s.Int)
-	}
 	return []byte(s.String()), nil
 }

@@ -182,11 +162,11 @@ func (s Uint64String) MarshalText() ([]byte, error) {
 }

 type ExecHeaderResponse struct {
-	Version string `json:"version"`
+	Version string `json:"version,omitempty"`
 	Data    struct {
-		Signature hexutil.Bytes `json:"signature"`
-		Message   *BuilderBid   `json:"message"`
-	} `json:"data"`
+		Signature hexutil.Bytes `json:"signature,omitempty"`
+		Message   *BuilderBid   `json:"message,omitempty"`
+	} `json:"data,omitempty"`
 }

 func (ehr *ExecHeaderResponse) ToProto() (*eth.SignedBuilderBid, error) {
@@ -232,35 +212,31 @@ func (h *ExecutionPayloadHeader) ToProto() (*v1.ExecutionPayloadHeader, error) {
 }

 type BuilderBid struct {
-	Header *ExecutionPayloadHeader `json:"header"`
-	Value  Uint256                 `json:"value"`
-	Pubkey hexutil.Bytes           `json:"pubkey"`
+	Header *ExecutionPayloadHeader `json:"header,omitempty"`
+	Value  Uint256                 `json:"value,omitempty"`
+	Pubkey hexutil.Bytes           `json:"pubkey,omitempty"`
 }

 type ExecutionPayloadHeader struct {
-	ParentHash       hexutil.Bytes `json:"parent_hash"`
-	FeeRecipient     hexutil.Bytes `json:"fee_recipient"`
-	StateRoot        hexutil.Bytes `json:"state_root"`
-	ReceiptsRoot     hexutil.Bytes `json:"receipts_root"`
-	LogsBloom        hexutil.Bytes `json:"logs_bloom"`
-	PrevRandao       hexutil.Bytes `json:"prev_randao"`
-	BlockNumber      Uint64String  `json:"block_number"`
-	GasLimit         Uint64String  `json:"gas_limit"`
-	GasUsed          Uint64String  `json:"gas_used"`
-	Timestamp        Uint64String  `json:"timestamp"`
-	ExtraData        hexutil.Bytes `json:"extra_data"`
-	BaseFeePerGas    Uint256       `json:"base_fee_per_gas"`
-	BlockHash        hexutil.Bytes `json:"block_hash"`
-	TransactionsRoot hexutil.Bytes `json:"transactions_root"`
+	ParentHash       hexutil.Bytes `json:"parent_hash,omitempty"`
+	FeeRecipient     hexutil.Bytes `json:"fee_recipient,omitempty"`
+	StateRoot        hexutil.Bytes `json:"state_root,omitempty"`
+	ReceiptsRoot     hexutil.Bytes `json:"receipts_root,omitempty"`
+	LogsBloom        hexutil.Bytes `json:"logs_bloom,omitempty"`
+	PrevRandao       hexutil.Bytes `json:"prev_randao,omitempty"`
+	BlockNumber      Uint64String  `json:"block_number,omitempty"`
+	GasLimit         Uint64String  `json:"gas_limit,omitempty"`
+	GasUsed          Uint64String  `json:"gas_used,omitempty"`
+	Timestamp        Uint64String  `json:"timestamp,omitempty"`
+	ExtraData        hexutil.Bytes `json:"extra_data,omitempty"`
+	BaseFeePerGas    Uint256       `json:"base_fee_per_gas,omitempty"`
+	BlockHash        hexutil.Bytes `json:"block_hash,omitempty"`
+	TransactionsRoot hexutil.Bytes `json:"transactions_root,omitempty"`
 	*v1.ExecutionPayloadHeader
 }

 func (h *ExecutionPayloadHeader) MarshalJSON() ([]byte, error) {
 	type MarshalCaller ExecutionPayloadHeader
-	baseFeePerGas, err := sszBytesToUint256(h.ExecutionPayloadHeader.BaseFeePerGas)
-	if err != nil {
-		return []byte{}, errors.Wrapf(err, "invalid BaseFeePerGas")
-	}
 	return json.Marshal(&MarshalCaller{
 		ParentHash:       h.ExecutionPayloadHeader.ParentHash,
 		FeeRecipient:     h.ExecutionPayloadHeader.FeeRecipient,
@@ -273,7 +249,7 @@ func (h *ExecutionPayloadHeader) MarshalJSON() ([]byte, error) {
 		GasUsed:          Uint64String(h.ExecutionPayloadHeader.GasUsed),
 		Timestamp:        Uint64String(h.ExecutionPayloadHeader.Timestamp),
 		ExtraData:        h.ExecutionPayloadHeader.ExtraData,
-		BaseFeePerGas:    baseFeePerGas,
+		BaseFeePerGas:    sszBytesToUint256(h.ExecutionPayloadHeader.BaseFeePerGas),
 		BlockHash:        h.ExecutionPayloadHeader.BlockHash,
 		TransactionsRoot: h.ExecutionPayloadHeader.TransactionsRoot,
 	})
@@ -293,25 +269,25 @@ func (h *ExecutionPayloadHeader) UnmarshalJSON(b []byte) error {
 }

 type ExecPayloadResponse struct {
-	Version string           `json:"version"`
-	Data    ExecutionPayload `json:"data"`
+	Version string           `json:"version,omitempty"`
+	Data    ExecutionPayload `json:"data,omitempty"`
 }

 type ExecutionPayload struct {
-	ParentHash    hexutil.Bytes   `json:"parent_hash"`
-	FeeRecipient  hexutil.Bytes   `json:"fee_recipient"`
-	StateRoot     hexutil.Bytes   `json:"state_root"`
-	ReceiptsRoot  hexutil.Bytes   `json:"receipts_root"`
-	LogsBloom     hexutil.Bytes   `json:"logs_bloom"`
-	PrevRandao    hexutil.Bytes   `json:"prev_randao"`
-	BlockNumber   Uint64String    `json:"block_number"`
-	GasLimit      Uint64String    `json:"gas_limit"`
-	GasUsed       Uint64String    `json:"gas_used"`
-	Timestamp     Uint64String    `json:"timestamp"`
-	ExtraData     hexutil.Bytes   `json:"extra_data"`
-	BaseFeePerGas Uint256         `json:"base_fee_per_gas"`
-	BlockHash     hexutil.Bytes   `json:"block_hash"`
-	Transactions  []hexutil.Bytes `json:"transactions"`
+	ParentHash    hexutil.Bytes   `json:"parent_hash,omitempty"`
+	FeeRecipient  hexutil.Bytes   `json:"fee_recipient,omitempty"`
+	StateRoot     hexutil.Bytes   `json:"state_root,omitempty"`
+	ReceiptsRoot  hexutil.Bytes   `json:"receipts_root,omitempty"`
+	LogsBloom     hexutil.Bytes   `json:"logs_bloom,omitempty"`
+	PrevRandao    hexutil.Bytes   `json:"prev_randao,omitempty"`
+	BlockNumber   Uint64String    `json:"block_number,omitempty"`
+	GasLimit      Uint64String    `json:"gas_limit,omitempty"`
+	GasUsed       Uint64String    `json:"gas_used,omitempty"`
+	Timestamp     Uint64String    `json:"timestamp,omitempty"`
+	ExtraData     hexutil.Bytes   `json:"extra_data,omitempty"`
+	BaseFeePerGas Uint256         `json:"base_fee_per_gas,omitempty"`
+	BlockHash     hexutil.Bytes   `json:"block_hash,omitempty"`
+	Transactions  []hexutil.Bytes `json:"transactions,omitempty"`
 }

 func (r *ExecPayloadResponse) ToProto() (*v1.ExecutionPayload, error) {
@@ -355,8 +331,8 @@ type BlindedBeaconBlockBodyBellatrix struct {

 func (r *SignedBlindedBeaconBlockBellatrix) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Message   *BlindedBeaconBlockBellatrix `json:"message"`
-		Signature hexutil.Bytes                `json:"signature"`
+		Message   *BlindedBeaconBlockBellatrix `json:"message,omitempty"`
+		Signature hexutil.Bytes                `json:"signature,omitempty"`
 	}{
 		Message:   &BlindedBeaconBlockBellatrix{r.SignedBlindedBeaconBlockBellatrix.Block},
 		Signature: r.SignedBlindedBeaconBlockBellatrix.Signature,
@@ -366,10 +342,10 @@ func (r *SignedBlindedBeaconBlockBellatrix) MarshalJSON() ([]byte, error) {
 func (b *BlindedBeaconBlockBellatrix) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
 		Slot          string                           `json:"slot"`
-		ProposerIndex string                           `json:"proposer_index"`
-		ParentRoot    hexutil.Bytes                    `json:"parent_root"`
-		StateRoot     hexutil.Bytes                    `json:"state_root"`
-		Body          *BlindedBeaconBlockBodyBellatrix `json:"body"`
+		ProposerIndex string                           `json:"proposer_index,omitempty"`
+		ParentRoot    hexutil.Bytes                    `json:"parent_root,omitempty"`
+		StateRoot     hexutil.Bytes                    `json:"state_root,omitempty"`
+		Body          *BlindedBeaconBlockBodyBellatrix `json:"body,omitempty"`
 	}{
 		Slot:          fmt.Sprintf("%d", b.Slot),
 		ProposerIndex: fmt.Sprintf("%d", b.ProposerIndex),
@@ -385,8 +361,8 @@ type ProposerSlashing struct {

 func (s *ProposerSlashing) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		SignedHeader1 *SignedBeaconBlockHeader `json:"signed_header_1"`
-		SignedHeader2 *SignedBeaconBlockHeader `json:"signed_header_2"`
+		SignedHeader1 *SignedBeaconBlockHeader `json:"signed_header_1,omitempty"`
+		SignedHeader2 *SignedBeaconBlockHeader `json:"signed_header_2,omitempty"`
 	}{
 		SignedHeader1: &SignedBeaconBlockHeader{s.ProposerSlashing.Header_1},
 		SignedHeader2: &SignedBeaconBlockHeader{s.ProposerSlashing.Header_2},
@@ -399,8 +375,8 @@ type SignedBeaconBlockHeader struct {

 func (h *SignedBeaconBlockHeader) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Header    *BeaconBlockHeader `json:"message"`
-		Signature hexutil.Bytes      `json:"signature"`
+		Header    *BeaconBlockHeader `json:"message,omitempty"`
+		Signature hexutil.Bytes      `json:"signature,omitempty"`
 	}{
 		Header:    &BeaconBlockHeader{h.SignedBeaconBlockHeader.Header},
 		Signature: h.SignedBeaconBlockHeader.Signature,
@@ -413,11 +389,11 @@ type BeaconBlockHeader struct {

 func (h *BeaconBlockHeader) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Slot          string        `json:"slot"`
-		ProposerIndex string        `json:"proposer_index"`
-		ParentRoot    hexutil.Bytes `json:"parent_root"`
-		StateRoot     hexutil.Bytes `json:"state_root"`
-		BodyRoot      hexutil.Bytes `json:"body_root"`
+		Slot          string        `json:"slot,omitempty"`
+		ProposerIndex string        `json:"proposer_index,omitempty"`
+		ParentRoot    hexutil.Bytes `json:"parent_root,omitempty"`
+		StateRoot     hexutil.Bytes `json:"state_root,omitempty"`
+		BodyRoot      hexutil.Bytes `json:"body_root,omitempty"`
 	}{
 		Slot:          fmt.Sprintf("%d", h.BeaconBlockHeader.Slot),
 		ProposerIndex: fmt.Sprintf("%d", h.BeaconBlockHeader.ProposerIndex),
@@ -437,9 +413,9 @@ func (a *IndexedAttestation) MarshalJSON() ([]byte, error) {
 		indices[i] = fmt.Sprintf("%d", a.AttestingIndices[i])
 	}
 	return json.Marshal(struct {
-		AttestingIndices []string         `json:"attesting_indices"`
-		Data             *AttestationData `json:"data"`
-		Signature        hexutil.Bytes    `json:"signature"`
+		AttestingIndices []string         `json:"attesting_indices,omitempty"`
+		Data             *AttestationData `json:"data,omitempty"`
+		Signature        hexutil.Bytes    `json:"signature,omitempty"`
 	}{
 		AttestingIndices: indices,
 		Data:             &AttestationData{a.IndexedAttestation.Data},
@@ -453,8 +429,8 @@ type AttesterSlashing struct {

 func (s *AttesterSlashing) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Attestation1 *IndexedAttestation `json:"attestation_1"`
-		Attestation2 *IndexedAttestation `json:"attestation_2"`
+		Attestation1 *IndexedAttestation `json:"attestation_1,omitempty"`
+		Attestation2 *IndexedAttestation `json:"attestation_2,omitempty"`
 	}{
 		Attestation1: &IndexedAttestation{s.Attestation_1},
 		Attestation2: &IndexedAttestation{s.Attestation_2},
@@ -467,8 +443,8 @@ type Checkpoint struct {

 func (c *Checkpoint) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Epoch string        `json:"epoch"`
-		Root  hexutil.Bytes `json:"root"`
+		Epoch string        `json:"epoch,omitempty"`
+		Root  hexutil.Bytes `json:"root,omitempty"`
 	}{
 		Epoch: fmt.Sprintf("%d", c.Checkpoint.Epoch),
 		Root:  c.Checkpoint.Root,
@@ -481,11 +457,11 @@ type AttestationData struct {

 func (a *AttestationData) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Slot            string        `json:"slot"`
-		Index           string        `json:"index"`
-		BeaconBlockRoot hexutil.Bytes `json:"beacon_block_root"`
-		Source          *Checkpoint   `json:"source"`
-		Target          *Checkpoint   `json:"target"`
+		Slot            string        `json:"slot,omitempty"`
+		Index           string        `json:"index,omitempty"`
+		BeaconBlockRoot hexutil.Bytes `json:"beacon_block_root,omitempty"`
+		Source          *Checkpoint   `json:"source,omitempty"`
+		Target          *Checkpoint   `json:"target,omitempty"`
 	}{
 		Slot:            fmt.Sprintf("%d", a.AttestationData.Slot),
 		Index:           fmt.Sprintf("%d", a.AttestationData.CommitteeIndex),
@@ -501,9 +477,9 @@ type Attestation struct {

 func (a *Attestation) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		AggregationBits hexutil.Bytes    `json:"aggregation_bits"`
-		Data            *AttestationData `json:"data"`
-		Signature       hexutil.Bytes    `json:"signature" ssz-size:"96"`
+		AggregationBits hexutil.Bytes    `json:"aggregation_bits,omitempty"`
+		Data            *AttestationData `json:"data,omitempty"`
+		Signature       hexutil.Bytes    `json:"signature,omitempty" ssz-size:"96"`
 	}{
 		AggregationBits: hexutil.Bytes(a.Attestation.AggregationBits),
 		Data:            &AttestationData{a.Attestation.Data},
@@ -517,10 +493,10 @@ type DepositData struct {

 func (d *DepositData) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		PublicKey             hexutil.Bytes `json:"pubkey"`
-		WithdrawalCredentials hexutil.Bytes `json:"withdrawal_credentials"`
-		Amount                string        `json:"amount"`
-		Signature             hexutil.Bytes `json:"signature"`
+		PublicKey             hexutil.Bytes `json:"pubkey,omitempty"`
+		WithdrawalCredentials hexutil.Bytes `json:"withdrawal_credentials,omitempty"`
+		Amount                string        `json:"amount,omitempty"`
+		Signature             hexutil.Bytes `json:"signature,omitempty"`
 	}{
 		PublicKey:             d.PublicKey,
 		WithdrawalCredentials: d.WithdrawalCredentials,
@@ -553,8 +529,8 @@ type SignedVoluntaryExit struct {

 func (sve *SignedVoluntaryExit) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Message   *VoluntaryExit `json:"message"`
-		Signature hexutil.Bytes  `json:"signature"`
+		Message   *VoluntaryExit `json:"message,omitempty"`
+		Signature hexutil.Bytes  `json:"signature,omitempty"`
 	}{
 		Signature: sve.SignedVoluntaryExit.Signature,
 		Message:   &VoluntaryExit{sve.SignedVoluntaryExit.Exit},
@@ -567,8 +543,8 @@ type VoluntaryExit struct {

 func (ve *VoluntaryExit) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		Epoch          string `json:"epoch"`
-		ValidatorIndex string `json:"validator_index"`
+		Epoch          string `json:"epoch,omitempty"`
+		ValidatorIndex string `json:"validator_index,omitempty"`
 	}{
 		Epoch:          fmt.Sprintf("%d", ve.Epoch),
 		ValidatorIndex: fmt.Sprintf("%d", ve.ValidatorIndex),
@@ -581,8 +557,8 @@ type SyncAggregate struct {

 func (s *SyncAggregate) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		SyncCommitteeBits      hexutil.Bytes `json:"sync_committee_bits"`
-		SyncCommitteeSignature hexutil.Bytes `json:"sync_committee_signature"`
+		SyncCommitteeBits      hexutil.Bytes `json:"sync_committee_bits,omitempty"`
+		SyncCommitteeSignature hexutil.Bytes `json:"sync_committee_signature,omitempty"`
 	}{
 		SyncCommitteeBits:      hexutil.Bytes(s.SyncAggregate.SyncCommitteeBits),
 		SyncCommitteeSignature: s.SyncAggregate.SyncCommitteeSignature,
@@ -595,9 +571,9 @@ type Eth1Data struct {

 func (e *Eth1Data) MarshalJSON() ([]byte, error) {
 	return json.Marshal(struct {
-		DepositRoot  hexutil.Bytes `json:"deposit_root"`
-		DepositCount string        `json:"deposit_count"`
-		BlockHash    hexutil.Bytes `json:"block_hash"`
+		DepositRoot  hexutil.Bytes `json:"deposit_root,omitempty"`
+		DepositCount string        `json:"deposit_count,omitempty"`
+		BlockHash    hexutil.Bytes `json:"block_hash,omitempty"`
 	}{
 		DepositRoot:  e.DepositRoot,
 		DepositCount: fmt.Sprintf("%d", e.DepositCount),
@@ -627,16 +603,16 @@ func (b *BlindedBeaconBlockBodyBellatrix) MarshalJSON() ([]byte, error) {
 		pros[i] = &ProposerSlashing{ProposerSlashing: b.BlindedBeaconBlockBodyBellatrix.ProposerSlashings[i]}
 	}
 	return json.Marshal(struct {
-		RandaoReveal           hexutil.Bytes           `json:"randao_reveal"`
-		Eth1Data               *Eth1Data               `json:"eth1_data"`
-		Graffiti               hexutil.Bytes           `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"`
+		RandaoReveal           hexutil.Bytes           `json:"randao_reveal,omitempty"`
+		Eth1Data               *Eth1Data               `json:"eth1_data,omitempty"`
+		Graffiti               hexutil.Bytes           `json:"graffiti,omitempty"`
+		ProposerSlashings      []*ProposerSlashing     `json:"proposer_slashings,omitempty"`
+		AttesterSlashings      []*AttesterSlashing     `json:"attester_slashings,omitempty"`
+		Attestations           []*Attestation          `json:"attestations,omitempty"`
+		Deposits               []*Deposit              `json:"deposits,omitempty"`
+		VoluntaryExits         []*SignedVoluntaryExit  `json:"voluntary_exits,omitempty"`
+		SyncAggregate          *SyncAggregate          `json:"sync_aggregate,omitempty"`
+		ExecutionPayloadHeader *ExecutionPayloadHeader `json:"execution_payload_header,omitempty"`
 	}{
 		RandaoReveal:           b.RandaoReveal,
 		Eth1Data:               &Eth1Data{b.BlindedBeaconBlockBodyBellatrix.Eth1Data},
@@ -650,9 +626,3 @@ func (b *BlindedBeaconBlockBodyBellatrix) MarshalJSON() ([]byte, error) {
 		ExecutionPayloadHeader: &ExecutionPayloadHeader{ExecutionPayloadHeader: b.BlindedBeaconBlockBodyBellatrix.ExecutionPayloadHeader},
 	})
 }
-
-type ErrorMessage struct {
-	Code        int      `json:"code"`
-	Message     string   `json:"message"`
-	Stacktraces []string `json:"stacktraces,omitempty"`
-}
--- a/api/client/builder/types_test.go
+++ b/api/client/builder/types_test.go
@@ -4,19 +4,16 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io"
 	"math/big"
-	"net/http"
-	"net/url"
 	"os"
 	"testing"

 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/golang/protobuf/proto"
 	"github.com/prysmaticlabs/go-bitfield"
-	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func ezDecode(t *testing.T, s string) []byte {
@@ -187,10 +184,8 @@ func TestExecutionHeaderResponseUnmarshal(t *testing.T) {
 }

 func TestExecutionHeaderResponseToProto(t *testing.T) {
-	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
-	v, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	v := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
 	hr := &ExecHeaderResponse{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponse), hr))
 	p, err := hr.ToProto()
@@ -375,8 +370,7 @@ func TestExecutionPayloadResponseToProto(t *testing.T) {
 	require.NoError(t, err)
 	txList := [][]byte{tx}

-	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
 	expected := &v1.ExecutionPayload{
 		ParentHash:    parentHash,
 		FeeRecipient:  feeRecipient,
@@ -584,8 +578,7 @@ func TestProposerSlashings(t *testing.T) {
 }

 func pbExecutionPayloadHeader(t *testing.T) *v1.ExecutionPayloadHeader {
-	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
 	return &v1.ExecutionPayloadHeader{
 		ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
 		FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
@@ -665,49 +658,6 @@ func TestMathBigUnmarshal(t *testing.T) {
 	require.NoError(t, u256.UnmarshalText([]byte("452312848583266388373324160190187140051835877600158453279131187530910662656")))
 }

-func TestIsValidUint256(t *testing.T) {
-	value, ok := new(big.Int), false
-
-	// negative uint256.max - 1
-	_, ok = value.SetString("-10000000000000000000000000000000000000000000000000000000000000000", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, 257, value.BitLen())
-	require.Equal(t, false, isValidUint256(value))
-
-	// negative uint256.max
-	_, ok = value.SetString("-ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, 256, value.BitLen())
-	require.Equal(t, false, isValidUint256(value))
-
-	// negative number
-	_, ok = value.SetString("-1", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, false, isValidUint256(value))
-
-	// uint256.min
-	_, ok = value.SetString("0", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, true, isValidUint256(value))
-
-	// positive number
-	_, ok = value.SetString("1", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, true, isValidUint256(value))
-
-	// uint256.max
-	_, ok = value.SetString("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, 256, value.BitLen())
-	require.Equal(t, true, isValidUint256(value))
-
-	// uint256.max + 1
-	_, ok = value.SetString("10000000000000000000000000000000000000000000000000000000000000000", 16)
-	require.Equal(t, true, ok)
-	require.Equal(t, 257, value.BitLen())
-	require.Equal(t, false, isValidUint256(value))
-}
-
 func TestUint256Unmarshal(t *testing.T) {
 	base10 := "452312848583266388373324160190187140051835877600158453279131187530910662656"
 	bi := new(big.Int)
@@ -724,36 +674,6 @@ func TestUint256Unmarshal(t *testing.T) {
 	require.Equal(t, expected, string(m))
 }

-func TestUint256UnmarshalNegative(t *testing.T) {
-	m := "-1"
-	var value Uint256
-	err := value.UnmarshalText([]byte(m))
-	require.ErrorContains(t, "unable to decode into Uint256", err)
-}
-
-func TestUint256UnmarshalMin(t *testing.T) {
-	m := "0"
-	var value Uint256
-	err := value.UnmarshalText([]byte(m))
-	require.NoError(t, err)
-}
-
-func TestUint256UnmarshalMax(t *testing.T) {
-	// 2**256-1 (uint256.max)
-	m := "115792089237316195423570985008687907853269984665640564039457584007913129639935"
-	var value Uint256
-	err := value.UnmarshalText([]byte(m))
-	require.NoError(t, err)
-}
-
-func TestUint256UnmarshalTooBig(t *testing.T) {
-	// 2**256 (one more than uint256.max)
-	m := "115792089237316195423570985008687907853269984665640564039457584007913129639936"
-	var value Uint256
-	err := value.UnmarshalText([]byte(m))
-	require.ErrorContains(t, "unable to decode into Uint256", err)
-}
-
 func TestMarshalBlindedBeaconBlockBodyBellatrix(t *testing.T) {
 	expected, err := os.ReadFile("testdata/blinded-block.json")
 	require.NoError(t, err)
@@ -785,12 +705,10 @@ func TestMarshalBlindedBeaconBlockBodyBellatrix(t *testing.T) {

 func TestRoundTripUint256(t *testing.T) {
 	vs := "4523128485832663883733241601901871400518358776001584532791311875309106626"
-	u, err := stringToUint256(vs)
-	require.NoError(t, err)
+	u := stringToUint256(vs)
 	sb := u.SSZBytes()
 	require.Equal(t, 32, len(sb))
-	uu, err := sszBytesToUint256(sb)
-	require.NoError(t, err)
+	uu := sszBytesToUint256(sb)
 	require.Equal(t, true, bytes.Equal(u.SSZBytes(), uu.SSZBytes()))
 	require.Equal(t, vs, uu.String())
 }
@@ -817,92 +735,3 @@ func TestExecutionPayloadHeaderRoundtrip(t *testing.T) {
 	require.NoError(t, err)
 	require.DeepEqual(t, string(expected[0:len(expected)-1]), string(m))
 }
-
-func TestErrorMessage_non200Err(t *testing.T) {
-	mockRequest := &http.Request{
-		URL: &url.URL{Path: "example.com"},
-	}
-	tests := []struct {
-		name        string
-		args        *http.Response
-		wantMessage string
-	}{
-		{
-			name: "204",
-			args: func() *http.Response {
-				message := ErrorMessage{
-					Code:    204,
-					Message: "No header is available",
-				}
-				r, err := json.Marshal(message)
-				require.NoError(t, err)
-				return &http.Response{
-					Request:    mockRequest,
-					StatusCode: 204,
-					Body:       io.NopCloser(bytes.NewReader(r)),
-				}
-			}(),
-			wantMessage: "No header is available",
-		},
-		{
-			name: "400",
-			args: func() *http.Response {
-				message := ErrorMessage{
-					Code:    400,
-					Message: "Unknown hash: missing parent hash",
-				}
-				r, err := json.Marshal(message)
-				require.NoError(t, err)
-				return &http.Response{
-					Request:    mockRequest,
-					StatusCode: 400,
-					Body:       io.NopCloser(bytes.NewReader(r)),
-				}
-			}(),
-			wantMessage: "Unknown hash: missing parent hash",
-		},
-		{
-			name: "500",
-			args: func() *http.Response {
-				message := ErrorMessage{
-					Code:    500,
-					Message: "Internal server error",
-				}
-				r, err := json.Marshal(message)
-				require.NoError(t, err)
-				return &http.Response{
-					Request:    mockRequest,
-					StatusCode: 500,
-					Body:       io.NopCloser(bytes.NewReader(r)),
-				}
-			}(),
-			wantMessage: "Internal server error",
-		},
-		{
-			name: "205",
-			args: func() *http.Response {
-				message := ErrorMessage{
-					Code:    205,
-					Message: "Reset Content",
-				}
-				r, err := json.Marshal(message)
-				require.NoError(t, err)
-				return &http.Response{
-					Request:    mockRequest,
-					StatusCode: 205,
-					Body:       io.NopCloser(bytes.NewReader(r)),
-				}
-			}(),
-			wantMessage: "did not receive 200 response from API",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			err := non200Err(tt.args)
-			if err != nil && tt.wantMessage != "" {
-				require.ErrorContains(t, tt.wantMessage, err)
-			}
-		})
-	}
-
-}
--- a/api/gateway/BUILD.bazel
+++ b/api/gateway/BUILD.bazel
@@ -8,7 +8,7 @@ go_library(
        "modifiers.go",
        "options.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v3/api/gateway",
+    importpath = "github.com/prysmaticlabs/prysm/api/gateway",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//validator:__subpackages__",
--- a/api/gateway/apimiddleware/BUILD.bazel
+++ b/api/gateway/apimiddleware/BUILD.bazel
@@ -10,7 +10,7 @@ go_library(
        "process_request.go",
        "structs.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v3/api/gateway/apimiddleware",
+    importpath = "github.com/prysmaticlabs/prysm/api/gateway/apimiddleware",
    visibility = ["//visibility:public"],
    deps = [
        "//api/grpc:go_default_library",
--- a/api/gateway/apimiddleware/param_handling.go
+++ b/api/gateway/apimiddleware/param_handling.go
@@ -7,7 +7,7 @@ import (
 	"strings"

 	"github.com/gorilla/mux"
-	butil "github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
+	butil "github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	"github.com/wealdtech/go-bytesutil"
 )

--- a/api/gateway/apimiddleware/param_handling_test.go
+++ b/api/gateway/apimiddleware/param_handling_test.go
@@ -6,8 +6,8 @@ import (
 	"testing"

 	"github.com/gorilla/mux"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func TestHandleURLParameters(t *testing.T) {
--- a/api/gateway/apimiddleware/process_request.go
+++ b/api/gateway/apimiddleware/process_request.go
@@ -10,7 +10,7 @@ import (
 	"strings"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/api/grpc"
+	"github.com/prysmaticlabs/prysm/api/grpc"
 )

 // DeserializeRequestBodyIntoContainer deserializes the request's body into an endpoint-specific struct.
--- a/api/gateway/apimiddleware/process_request_test.go
+++ b/api/gateway/apimiddleware/process_request_test.go
@@ -8,9 +8,9 @@ import (
 	"strings"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/api/grpc"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/api/grpc"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/sirupsen/logrus/hooks/test"
 )

--- a/api/gateway/gateway.go
+++ b/api/gateway/gateway.go
@@ -13,8 +13,8 @@ import (
 	"github.com/gorilla/mux"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/api/gateway/apimiddleware"
-	"github.com/prysmaticlabs/prysm/v3/runtime"
+	"github.com/prysmaticlabs/prysm/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/runtime"
 	"github.com/rs/cors"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/connectivity"
--- a/api/gateway/gateway_test.go
+++ b/api/gateway/gateway_test.go
@@ -10,10 +10,10 @@ import (
 	"testing"

 	"github.com/gorilla/mux"
-	"github.com/prysmaticlabs/prysm/v3/api/gateway/apimiddleware"
-	"github.com/prysmaticlabs/prysm/v3/cmd/beacon-chain/flags"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"github.com/urfave/cli/v2"
 )
--- a/api/gateway/options.go
+++ b/api/gateway/options.go
@@ -5,7 +5,7 @@ import (

 	"github.com/gorilla/mux"
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
-	"github.com/prysmaticlabs/prysm/v3/api/gateway/apimiddleware"
+	"github.com/prysmaticlabs/prysm/api/gateway/apimiddleware"
 )

 type Option 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/v3/api/grpc",
+    importpath = "github.com/prysmaticlabs/prysm/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/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/metadata"
--- 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/v3/api/pagination",
+    importpath = "github.com/prysmaticlabs/prysm/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/v3/config/params"
+	"github.com/prysmaticlabs/prysm/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/v3/api/pagination"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/api/pagination"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func TestStartAndEndPage(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/v3/async",
+    importpath = "github.com/prysmaticlabs/prysm/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/v3/async/abool",
+    importpath = "github.com/prysmaticlabs/prysm/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/v3/async"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/async"
+	"github.com/prysmaticlabs/prysm/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/v3/async"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	"github.com/prysmaticlabs/prysm/async"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/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/v3/async/event",
+    importpath = "github.com/prysmaticlabs/prysm/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/v3/async/event"
+	"github.com/prysmaticlabs/prysm/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/v3/async/event"
+	"github.com/prysmaticlabs/prysm/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/v3/async/event"
+	"github.com/prysmaticlabs/prysm/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/v3/testing/assert"
+	"github.com/prysmaticlabs/prysm/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/v3/time/mclock"
+	"github.com/prysmaticlabs/prysm/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/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/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/v3/async"
+	"github.com/prysmaticlabs/prysm/async"
 )

 func TestEveryRuns(t *testing.T) {
--- a/async/multilock.go
+++ b/async/multilock.go
@@ -3,9 +3,7 @@ Copyright 2017 Albert Tedja
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
-
-	http://www.apache.org/licenses/LICENSE-2.0
-
+    http://www.apache.org/licenses/LICENSE-2.0
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
--- a/async/multilock_test.go
+++ b/async/multilock_test.go
@@ -3,9 +3,7 @@ Copyright 2017 Albert Tedja
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
-
-	http://www.apache.org/licenses/LICENSE-2.0
-
+    http://www.apache.org/licenses/LICENSE-2.0
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
--- a/async/scatter_test.go
+++ b/async/scatter_test.go
@@ -5,9 +5,9 @@ import (
 	"sync"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/async"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/async"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func TestDouble(t *testing.T) {
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -24,7 +24,7 @@ go_library(
        "state_balance_cache.go",
        "weak_subjectivity_checks.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v3/beacon-chain/blockchain",
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/blockchain",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//cmd/beacon-chain:__subpackages__",
@@ -48,24 +48,24 @@ go_library(
        "//beacon-chain/db: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",
+        "//beacon-chain/forkchoice/protoarray: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/powchain:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//beacon-chain/state/stategen:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
        "//config/features:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
-        "//consensus-types/payload-attribute:go_default_library",
        "//consensus-types/primitives:go_default_library",
+        "//consensus-types/wrapper:go_default_library",
        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
@@ -129,16 +129,16 @@ go_test(
        "//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",
-        "//beacon-chain/state/state-native:go_default_library",
+        "//beacon-chain/powchain:go_default_library",
+        "//beacon-chain/powchain/testing:go_default_library",
        "//beacon-chain/state/stateutil:go_default_library",
+        "//beacon-chain/state/v1:go_default_library",
+        "//beacon-chain/state/v3:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
+        "//consensus-types/wrapper:go_default_library",
        "//container/trie:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
@@ -186,13 +186,12 @@ go_test(
        "//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",
+        "//beacon-chain/powchain:go_default_library",
+        "//beacon-chain/powchain/testing:go_default_library",
        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
+        "//consensus-types/wrapper:go_default_library",
        "//container/trie:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
--- a/beacon-chain/blockchain/chain_info.go
+++ b/beacon-chain/blockchain/chain_info.go
@@ -1,22 +1,21 @@
 package blockchain

 import (
-	"bytes"
 	"context"
 	"time"

-	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )

@@ -25,8 +24,10 @@ import (
 type ChainInfoFetcher interface {
 	HeadFetcher
 	FinalizationFetcher
+	GenesisFetcher
 	CanonicalFetcher
 	ForkFetcher
+	TimeFetcher
 	HeadDomainFetcher
 }

@@ -68,8 +69,6 @@ type HeadFetcher interface {
 type ForkFetcher interface {
 	ForkChoicer() forkchoice.ForkChoicer
 	CurrentFork() *ethpb.Fork
-	GenesisFetcher
-	TimeFetcher
 }

 // CanonicalFetcher retrieves the current chain's canonical information.
@@ -162,7 +161,7 @@ func (s *Service) HeadBlock(ctx context.Context) (interfaces.SignedBeaconBlock,
 	defer s.headLock.RUnlock()

 	if s.hasHeadState() {
-		return s.headBlock()
+		return s.headBlock(), nil
 	}

 	return s.cfg.BeaconDB.HeadBlock(ctx)
@@ -300,26 +299,13 @@ func (s *Service) ForkChoicer() forkchoice.ForkChoicer {

 // IsOptimistic returns true if the current head is optimistic.
 func (s *Service) IsOptimistic(ctx context.Context) (bool, error) {
+	s.headLock.RLock()
+	defer s.headLock.RUnlock()
 	if slots.ToEpoch(s.CurrentSlot()) < params.BeaconConfig().BellatrixForkEpoch {
 		return false, nil
 	}
-	s.headLock.RLock()
-	headRoot := s.head.root
-	s.headLock.RUnlock()

-	if s.cfg.ForkChoiceStore.AllTipsAreInvalid() {
-		return true, nil
-	}
-	optimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(headRoot)
-	if err == nil {
-		return optimistic, nil
-	}
-	if !errors.Is(err, doublylinkedtree.ErrNilNode) {
-		return true, err
-	}
-	// If fockchoice does not have the headroot, then the node is considered
-	// optimistic
-	return true, nil
+	return s.IsOptimisticForRoot(ctx, s.head.root)
 }

 // IsFinalized returns true if the input root is finalized.
@@ -328,11 +314,6 @@ func (s *Service) IsFinalized(ctx context.Context, root [32]byte) bool {
 	if s.ForkChoicer().FinalizedCheckpoint().Root == root {
 		return true
 	}
-	// If node exists in our store, then it is not
-	// finalized.
-	if s.ForkChoicer().HasNode(root) {
-		return false
-	}
 	return s.cfg.BeaconDB.IsFinalizedBlock(ctx, root)
 }

@@ -343,27 +324,17 @@ func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool,
 	if err == nil {
 		return optimistic, nil
 	}
-	if !errors.Is(err, doublylinkedtree.ErrNilNode) {
+	if err != protoarray.ErrUnknownNodeRoot && err != doublylinkedtree.ErrNilNode {
 		return false, err
 	}
-	// if the requested root is the headroot and the root is not found in
-	// forkchoice, the node should respond that it is optimistic
-	headRoot, err := s.HeadRoot(ctx)
-	if err != nil {
-		return true, err
-	}
-	if bytes.Equal(headRoot, root[:]) {
-		return true, nil
-	}
-
 	ss, err := s.cfg.BeaconDB.StateSummary(ctx, root)
 	if err != nil {
 		return false, err
 	}
-
 	if ss == nil {
-		return true, errInvalidNilSummary
+		return false, errInvalidNilSummary
 	}
+
 	validatedCheckpoint, err := s.cfg.BeaconDB.LastValidatedCheckpoint(ctx)
 	if err != nil {
 		return false, err
@@ -372,14 +343,8 @@ func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool,
 		return true, nil
 	}

-	// Historical non-canonical blocks here are returned as optimistic for safety.
-	isCanonical, err := s.IsCanonical(ctx, root)
-	if err != nil {
-		return false, err
-	}
-
 	if slots.ToEpoch(ss.Slot)+1 < validatedCheckpoint.Epoch {
-		return !isCanonical, nil
+		return false, nil
 	}

 	// Checkpoint root could be zeros before the first finalized epoch. Use genesis root if the case.
@@ -394,6 +359,13 @@ func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool,
 	if ss.Slot > lastValidated.Slot {
 		return true, nil
 	}
+
+	isCanonical, err := s.IsCanonical(ctx, root)
+	if err != nil {
+		return false, err
+	}
+
+	// Historical non-canonical blocks here are returned as optimistic for safety.
 	return !isCanonical, nil
 }

--- a/beacon-chain/blockchain/chain_info_norace_test.go
+++ b/beacon-chain/blockchain/chain_info_norace_test.go
@@ -4,13 +4,12 @@ import (
 	"context"
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 )

 func TestHeadSlot_DataRace(t *testing.T) {
@@ -18,7 +17,7 @@ func TestHeadSlot_DataRace(t *testing.T) {
 	s := &Service{
 		cfg: &config{BeaconDB: beaconDB},
 	}
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	st, _ := util.DeterministicGenesisState(t, 1)
 	wait := make(chan struct{})
@@ -33,10 +32,10 @@ func TestHeadSlot_DataRace(t *testing.T) {
 func TestHeadRoot_DataRace(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	s := &Service{
-		cfg:  &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
+		cfg:  &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB)},
 		head: &head{root: [32]byte{'A'}},
 	}
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	wait := make(chan struct{})
 	st, _ := util.DeterministicGenesisState(t, 1)
@@ -52,13 +51,13 @@ func TestHeadRoot_DataRace(t *testing.T) {

 func TestHeadBlock_DataRace(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
-	wsb, err := blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlock{Block: &ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}}})
+	wsb, err := wrapper.WrappedSignedBeaconBlock(&ethpb.SignedBeaconBlock{})
 	require.NoError(t, err)
 	s := &Service{
-		cfg:  &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
+		cfg:  &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB)},
 		head: &head{block: wsb},
 	}
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	wait := make(chan struct{})
 	st, _ := util.DeterministicGenesisState(t, 1)
@@ -75,9 +74,9 @@ func TestHeadBlock_DataRace(t *testing.T) {
 func TestHeadState_DataRace(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	s := &Service{
-		cfg: &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
+		cfg: &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB)},
 	}
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	wait := make(chan struct{})
 	st, _ := util.DeterministicGenesisState(t, 1)
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -5,22 +5,24 @@ import (
 	"testing"
 	"time"

-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	state_native "github.com/prysmaticlabs/prysm/v3/beacon-chain/state/state-native"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	enginev1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
+	v3 "github.com/prysmaticlabs/prysm/beacon-chain/state/v3"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 	"google.golang.org/protobuf/proto"
 )

@@ -59,7 +61,7 @@ func prepareForkchoiceState(
 	}

 	base.BlockRoots[0] = append(base.BlockRoots[0], blockRoot[:]...)
-	st, err := state_native.InitializeFromProtoBellatrix(base)
+	st, err := v3.InitializeFromProto(base)
 	return st, blockRoot, err
 }

@@ -80,11 +82,11 @@ func TestService_ForkChoiceStore(t *testing.T) {
 func TestFinalizedCheckpt_GenesisRootOk(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithForkChoiceStore(fcs),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -105,11 +107,11 @@ func TestFinalizedCheckpt_GenesisRootOk(t *testing.T) {
 func TestCurrentJustifiedCheckpt_CanRetrieve(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithForkChoiceStore(fcs),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -123,23 +125,20 @@ func TestCurrentJustifiedCheckpt_CanRetrieve(t *testing.T) {

 func TestHeadSlot_CanRetrieve(t *testing.T) {
 	c := &Service{}
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
+	s, err := v1.InitializeFromProto(&ethpb.BeaconState{})
 	require.NoError(t, err)
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b.Block().SetSlot(100)
-	c.head = &head{block: b, state: s}
+	c.head = &head{slot: 100, state: s}
 	assert.Equal(t, types.Slot(100), c.HeadSlot())
 }

 func TestHeadRoot_CanRetrieve(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithForkChoiceStore(fcs),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -154,11 +153,11 @@ func TestHeadRoot_CanRetrieve(t *testing.T) {
 func TestHeadRoot_UseDB(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithForkChoiceStore(fcs),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -167,7 +166,7 @@ func TestHeadRoot_UseDB(t *testing.T) {
 	b := util.NewBeaconBlock()
 	br, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	wsb, err := blocks.NewSignedBeaconBlock(b)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
 	require.NoError(t, err)
 	require.NoError(t, beaconDB.SaveBlock(ctx, wsb))
 	require.NoError(t, beaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{Root: br[:]}))
@@ -180,28 +179,26 @@ func TestHeadRoot_UseDB(t *testing.T) {
 func TestHeadBlock_CanRetrieve(t *testing.T) {
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 1
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
+	s, err := v1.InitializeFromProto(&ethpb.BeaconState{})
 	require.NoError(t, err)
-	wsb, err := blocks.NewSignedBeaconBlock(b)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
 	require.NoError(t, err)
 	c := &Service{}
 	c.head = &head{block: wsb, state: s}

-	received, err := c.HeadBlock(context.Background())
+	recevied, err := c.HeadBlock(context.Background())
 	require.NoError(t, err)
-	pb, err := received.Proto()
-	require.NoError(t, err)
-	assert.DeepEqual(t, b, pb, "Incorrect head block received")
+	assert.DeepEqual(t, b, recevied.Proto(), "Incorrect head block received")
 }

 func TestHeadState_CanRetrieve(t *testing.T) {
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: 2, GenesisValidatorsRoot: params.BeaconConfig().ZeroHash[:]})
+	s, err := v1.InitializeFromProto(&ethpb.BeaconState{Slot: 2, GenesisValidatorsRoot: params.BeaconConfig().ZeroHash[:]})
 	require.NoError(t, err)
 	c := &Service{}
 	c.head = &head{state: s}
 	headState, err := c.HeadState(context.Background())
 	require.NoError(t, err)
-	assert.DeepEqual(t, headState.ToProtoUnsafe(), s.ToProtoUnsafe(), "Incorrect head state received")
+	assert.DeepEqual(t, headState.InnerStateUnsafe(), s.InnerStateUnsafe(), "Incorrect head state received")
 }

 func TestGenesisTime_CanRetrieve(t *testing.T) {
@@ -212,7 +209,7 @@ func TestGenesisTime_CanRetrieve(t *testing.T) {

 func TestCurrentFork_CanRetrieve(t *testing.T) {
 	f := &ethpb.Fork{Epoch: 999}
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{Fork: f})
+	s, err := v1.InitializeFromProto(&ethpb.BeaconState{Fork: f})
 	require.NoError(t, err)
 	c := &Service{}
 	c.head = &head{state: s}
@@ -237,7 +234,7 @@ func TestGenesisValidatorsRoot_CanRetrieve(t *testing.T) {
 	c := &Service{}
 	assert.Equal(t, [32]byte{}, c.GenesisValidatorsRoot(), "Did not get correct genesis validators root")

-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{GenesisValidatorsRoot: []byte{'a'}})
+	s, err := v1.InitializeFromProto(&ethpb.BeaconState{GenesisValidatorsRoot: []byte{'a'}})
 	require.NoError(t, err)
 	c.head = &head{state: s}
 	assert.Equal(t, [32]byte{'a'}, c.GenesisValidatorsRoot(), "Did not get correct genesis validators root")
@@ -251,7 +248,7 @@ func TestHeadETH1Data_Nil(t *testing.T) {

 func TestHeadETH1Data_CanRetrieve(t *testing.T) {
 	d := &ethpb.Eth1Data{DepositCount: 999}
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{Eth1Data: d})
+	s, err := v1.InitializeFromProto(&ethpb.BeaconState{Eth1Data: d})
 	require.NoError(t, err)
 	c := &Service{}
 	c.head = &head{state: s}
@@ -307,22 +304,12 @@ func TestService_HeadGenesisValidatorsRoot(t *testing.T) {
 	root = c.HeadGenesisValidatorsRoot()
 	require.DeepEqual(t, root[:], s.GenesisValidatorsRoot())
 }
-
-//
-//  A <- B <- C
-//   \    \
-//    \    ---------- E
-//     ---------- D
-
-func TestService_ChainHeads(t *testing.T) {
+func TestService_ChainHeads_ProtoArray(t *testing.T) {
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}}
+	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New()}}
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	st, blkRoot, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
-	require.NoError(t, err)
-	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
-	st, blkRoot, err = prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	st, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
 	st, blkRoot, err = prepareForkchoiceState(ctx, 101, [32]byte{'b'}, [32]byte{'a'}, params.BeaconConfig().ZeroHash, ojc, ofc)
@@ -338,9 +325,44 @@ func TestService_ChainHeads(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))

+	roots, slots := c.ChainHeads()
+	require.DeepEqual(t, [][32]byte{{'c'}, {'d'}, {'e'}}, roots)
+	require.DeepEqual(t, []types.Slot{102, 103, 104}, slots)
+}
+
+//
+//  A <- B <- C
+//   \    \
+//    \    ---------- E
+//     ---------- D
+
+func TestService_ChainHeads_DoublyLinkedTree(t *testing.T) {
+	ctx := context.Background()
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}}
+	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	st, blkRoot, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 101, [32]byte{'b'}, [32]byte{'a'}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 102, [32]byte{'c'}, [32]byte{'b'}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 103, [32]byte{'d'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 104, [32]byte{'e'}, [32]byte{'b'}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+
 	roots, slots := c.ChainHeads()
 	require.Equal(t, 3, len(roots))
-	rootMap := map[[32]byte]types.Slot{{'c'}: 102, {'d'}: 103, {'e'}: 104}
+	rootMap := map[[32]byte]types.Slot{[32]byte{'c'}: 102, [32]byte{'d'}: 103, [32]byte{'e'}: 104}
 	for i, root := range roots {
 		slot, ok := rootMap[root]
 		require.Equal(t, true, ok)
@@ -406,7 +428,29 @@ func TestService_HeadValidatorIndexToPublicKeyNil(t *testing.T) {
 	require.Equal(t, [fieldparams.BLSPubkeyLength]byte{}, p)
 }

-func TestService_IsOptimistic(t *testing.T) {
+func TestService_IsOptimistic_ProtoArray(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig()
+	cfg.BellatrixForkEpoch = 0
+	params.OverrideBeaconConfig(cfg)
+
+	ctx := context.Background()
+	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	st, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 101, [32]byte{'b'}, [32]byte{'a'}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+
+	opt, err := c.IsOptimistic(ctx)
+	require.NoError(t, err)
+	require.Equal(t, true, opt)
+}
+
+func TestService_IsOptimistic_DoublyLinkedTree(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	cfg := params.BeaconConfig()
 	cfg.BellatrixForkEpoch = 0
@@ -415,7 +459,7 @@ func TestService_IsOptimistic(t *testing.T) {
 	ctx := context.Background()
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	st, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
@@ -436,9 +480,9 @@ func TestService_IsOptimisticBeforeBellatrix(t *testing.T) {
 	require.Equal(t, false, opt)
 }

-func TestService_IsOptimisticForRoot(t *testing.T) {
+func TestService_IsOptimisticForRoot_ProtoArray(t *testing.T) {
 	ctx := context.Background()
-	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{ForkChoiceStore: protoarray.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	st, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
@@ -453,10 +497,86 @@ func TestService_IsOptimisticForRoot(t *testing.T) {
 	require.Equal(t, true, opt)
 }

-func TestService_IsOptimisticForRoot_DB(t *testing.T) {
+func TestService_IsOptimisticForRoot_DoublyLinkedTree(t *testing.T) {
+	ctx := context.Background()
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	st, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 101, [32]byte{'b'}, [32]byte{'a'}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+
+	opt, err := c.IsOptimisticForRoot(ctx, [32]byte{'a'})
+	require.NoError(t, err)
+	require.Equal(t, true, opt)
+}
+
+func TestService_IsOptimisticForRoot_DB_ProtoArray(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: protoarray.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
+	c.head = &head{root: params.BeaconConfig().ZeroHash}
+	b := util.NewBeaconBlock()
+	b.Block.Slot = 10
+	br, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, context.Background(), beaconDB, b)
+	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: br[:], Slot: 10}))
+
+	optimisticBlock := util.NewBeaconBlock()
+	optimisticBlock.Block.Slot = 97
+	optimisticRoot, err := optimisticBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, context.Background(), beaconDB, optimisticBlock)
+
+	validatedBlock := util.NewBeaconBlock()
+	validatedBlock.Block.Slot = 9
+	validatedRoot, err := validatedBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, context.Background(), beaconDB, validatedBlock)
+
+	validatedCheckpoint := &ethpb.Checkpoint{Root: br[:]}
+	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, validatedCheckpoint))
+
+	_, err = c.IsOptimisticForRoot(ctx, optimisticRoot)
+	require.ErrorContains(t, "nil summary returned from the DB", err)
+
+	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: optimisticRoot[:], Slot: 11}))
+	optimistic, err := c.IsOptimisticForRoot(ctx, optimisticRoot)
+	require.NoError(t, err)
+	require.Equal(t, true, optimistic)
+
+	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: validatedRoot[:], Slot: 9}))
+	cp := &ethpb.Checkpoint{
+		Epoch: 1,
+		Root:  validatedRoot[:],
+	}
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, validatedRoot))
+	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, cp))
+
+	validated, err := c.IsOptimisticForRoot(ctx, validatedRoot)
+	require.NoError(t, err)
+	require.Equal(t, false, validated)
+
+	// Before the first finalized epoch, finalized root could be zeros.
+	validatedCheckpoint = &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, br))
+	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: params.BeaconConfig().ZeroHash[:], Slot: 10}))
+	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, validatedCheckpoint))
+
+	require.NoError(t, beaconDB.SaveStateSummary(context.Background(), &ethpb.StateSummary{Root: optimisticRoot[:], Slot: 11}))
+	optimistic, err = c.IsOptimisticForRoot(ctx, optimisticRoot)
+	require.NoError(t, err)
+	require.Equal(t, true, optimistic)
+}
+
+func TestService_IsOptimisticForRoot_DB_DoublyLinkedTree(t *testing.T) {
+	beaconDB := testDB.SetupDB(t)
+	ctx := context.Background()
+	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
@@ -514,7 +634,7 @@ func TestService_IsOptimisticForRoot_DB(t *testing.T) {
 func TestService_IsOptimisticForRoot_DB_non_canonical(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
-	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	c := &Service{cfg: &config{BeaconDB: beaconDB, ForkChoiceStore: doublylinkedtree.New()}, head: &head{slot: 101, root: [32]byte{'b'}}}
 	c.head = &head{root: params.BeaconConfig().ZeroHash}
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 10
--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -8,17 +8,19 @@ var (
 	// ErrInvalidBlockHashPayloadStatus is returned when the payload has invalid block hash.
 	ErrInvalidBlockHashPayloadStatus = invalidBlock{error: errors.New("received an INVALID_BLOCK_HASH payload from execution engine")}
 	// ErrUndefinedExecutionEngineError is returned when the execution engine returns an error that is not defined
-	ErrUndefinedExecutionEngineError = errors.New("received an undefined execution engine error")
+	ErrUndefinedExecutionEngineError = errors.New("received an undefined ee error")
 	// errNilFinalizedInStore is returned when a nil finalized checkpt is returned from store.
 	errNilFinalizedInStore = errors.New("nil finalized checkpoint returned from store")
 	// errNilFinalizedCheckpoint is returned when a nil finalized checkpt is returned from a state.
 	errNilFinalizedCheckpoint = errors.New("nil finalized checkpoint returned from state")
 	// errNilJustifiedCheckpoint is returned when a nil justified checkpt is returned from a state.
-	errNilJustifiedCheckpoint = errors.New("nil justified checkpoint returned from state")
+	errNilJustifiedCheckpoint = errors.New("nil finalized checkpoint returned from state")
 	// errInvalidNilSummary is returned when a nil summary is returned from the DB.
 	errInvalidNilSummary = errors.New("nil summary returned from the DB")
 	// errWrongBlockCount is returned when the wrong number of blocks or block roots is used
 	errWrongBlockCount = errors.New("wrong number of blocks or block roots")
+	// block is not a valid optimistic candidate block
+	errNotOptimisticCandidate = errors.New("block is not suitable for optimistic sync")
 	// errBlockNotFoundInCacheOrDB is returned when a block is not found in the cache or DB.
 	errBlockNotFoundInCacheOrDB = errors.New("block not found in cache or db")
 	// errNilStateFromStategen is returned when a nil state is returned from the state generator.
@@ -38,14 +40,12 @@ var (
 // The block is deemed invalid according to execution layer client.
 // The block violates certain fork choice rules (before finalized slot, not finalized ancestor)
 type invalidBlock struct {
-	invalidAncestorRoots [][32]byte
 	error
 	root [32]byte
 }

 type invalidBlockError interface {
 	Error() string
-	InvalidAncestorRoots() [][32]byte
 	BlockRoot() [32]byte
 }

@@ -54,11 +54,6 @@ func (e invalidBlock) BlockRoot() [32]byte {
 	return e.root
 }

-// InvalidAncestorRoots returns an optional list of invalid roots of the invalid block which leads up last valid root.
-func (e invalidBlock) InvalidAncestorRoots() [][32]byte {
-	return e.invalidAncestorRoots
-}
-
 // IsInvalidBlock returns true if the error has `invalidBlock`.
 func IsInvalidBlock(e error) bool {
 	if e == nil {
@@ -83,15 +78,3 @@ func InvalidBlockRoot(e error) [32]byte {
 	}
 	return d.BlockRoot()
 }
-
-// InvalidAncestorRoots returns a list of invalid roots up to last valid root.
-func InvalidAncestorRoots(e error) [][32]byte {
-	if e == nil {
-		return [][32]byte{}
-	}
-	d, ok := e.(invalidBlockError)
-	if !ok {
-		return [][32]byte{}
-	}
-	return d.InvalidAncestorRoots()
-}
--- a/beacon-chain/blockchain/error_test.go
+++ b/beacon-chain/blockchain/error_test.go
@@ -4,7 +4,7 @@ import (
 	"testing"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func TestIsInvalidBlock(t *testing.T) {
@@ -14,7 +14,6 @@ func TestIsInvalidBlock(t *testing.T) {

 	newErr := errors.Wrap(err, "wrap me")
 	require.Equal(t, true, IsInvalidBlock(newErr))
-	require.DeepEqual(t, [][32]byte(nil), InvalidAncestorRoots(err))
 }

 func TestInvalidBlockRoot(t *testing.T) {
@@ -23,14 +22,4 @@ func TestInvalidBlockRoot(t *testing.T) {

 	err := invalidBlock{error: ErrInvalidPayload, root: [32]byte{'a'}}
 	require.Equal(t, [32]byte{'a'}, InvalidBlockRoot(err))
-	require.DeepEqual(t, [][32]byte(nil), InvalidAncestorRoots(err))
-}
-
-func TestInvalidRoots(t *testing.T) {
-	roots := [][32]byte{{'d'}, {'b'}, {'c'}}
-	err := invalidBlock{error: ErrInvalidPayload, root: [32]byte{'a'}, invalidAncestorRoots: roots}
-
-	require.Equal(t, true, IsInvalidBlock(err))
-	require.Equal(t, [32]byte{'a'}, InvalidBlockRoot(err))
-	require.DeepEqual(t, roots, InvalidAncestorRoots(err))
 }
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -5,28 +5,24 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/time"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db/kv"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/execution"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	consensusblocks "github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	payloadattribute "github.com/prysmaticlabs/prysm/v3/consensus-types/payload-attribute"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	enginev1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/kv"
+	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )

-var defaultLatestValidHash = bytesutil.PadTo([]byte{0xff}, 32)
-
 // notifyForkchoiceUpdateArg is the argument for the forkchoice update notification `notifyForkchoiceUpdate`.
 type notifyForkchoiceUpdateArg struct {
 	headState state.BeaconState
@@ -69,26 +65,31 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 	}

 	nextSlot := s.CurrentSlot() + 1 // Cache payload ID for next slot proposer.
-	hasAttr, attr, proposerId := s.getPayloadAttribute(ctx, arg.headState, nextSlot)
+	hasAttr, attr, proposerId, err := s.getPayloadAttribute(ctx, arg.headState, nextSlot)
+	if err != nil {
+		log.WithError(err).Error("Could not get head payload attribute")
+		return nil, nil
+	}

 	payloadID, lastValidHash, err := s.cfg.ExecutionEngineCaller.ForkchoiceUpdated(ctx, fcs, attr)
 	if err != nil {
 		switch err {
-		case execution.ErrAcceptedSyncingPayloadStatus:
+		case powchain.ErrAcceptedSyncingPayloadStatus:
 			forkchoiceUpdatedOptimisticNodeCount.Inc()
 			log.WithFields(logrus.Fields{
 				"headSlot":                  headBlk.Slot(),
 				"headPayloadBlockHash":      fmt.Sprintf("%#x", bytesutil.Trunc(headPayload.BlockHash())),
 				"finalizedPayloadBlockHash": fmt.Sprintf("%#x", bytesutil.Trunc(finalizedHash[:])),
 			}).Info("Called fork choice updated with optimistic block")
-			return payloadID, nil
-		case execution.ErrInvalidPayloadStatus:
-			forkchoiceUpdatedInvalidNodeCount.Inc()
-			headRoot := arg.headRoot
-			if len(lastValidHash) == 0 {
-				lastValidHash = defaultLatestValidHash
+			err := s.optimisticCandidateBlock(ctx, headBlk)
+			if err != nil {
+				log.WithError(err).Error("Optimistic block failed to be candidate")
 			}
-			invalidRoots, err := s.ForkChoicer().SetOptimisticToInvalid(ctx, headRoot, headBlk.ParentRoot(), bytesutil.ToBytes32(lastValidHash))
+			return payloadID, nil
+		case powchain.ErrInvalidPayloadStatus:
+			newPayloadInvalidNodeCount.Inc()
+			headRoot := arg.headRoot
+			invalidRoots, err := s.ForkChoicer().SetOptimisticToInvalid(ctx, headRoot, bytesutil.ToBytes32(headBlk.ParentRoot()), bytesutil.ToBytes32(lastValidHash))
 			if err != nil {
 				log.WithError(err).Error("Could not set head root to invalid")
 				return nil, nil
@@ -100,12 +101,8 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho

 			r, err := s.cfg.ForkChoiceStore.Head(ctx, s.justifiedBalances.balances)
 			if err != nil {
-				log.WithFields(logrus.Fields{
-					"slot":                 headBlk.Slot(),
-					"blockRoot":            fmt.Sprintf("%#x", bytesutil.Trunc(headRoot[:])),
-					"invalidChildrenCount": len(invalidRoots),
-				}).Warn("Pruned invalid blocks, could not update head root")
-				return nil, invalidBlock{error: ErrInvalidPayload, root: arg.headRoot, invalidAncestorRoots: invalidRoots}
+				log.WithError(err).Error("Could not get head root")
+				return nil, nil
 			}
 			b, err := s.getBlock(ctx, r)
 			if err != nil {
@@ -131,12 +128,12 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 			}

 			log.WithFields(logrus.Fields{
-				"slot":                 headBlk.Slot(),
-				"blockRoot":            fmt.Sprintf("%#x", bytesutil.Trunc(headRoot[:])),
-				"invalidChildrenCount": len(invalidRoots),
-				"newHeadRoot":          fmt.Sprintf("%#x", bytesutil.Trunc(r[:])),
+				"slot":         headBlk.Slot(),
+				"blockRoot":    fmt.Sprintf("%#x", bytesutil.Trunc(headRoot[:])),
+				"invalidCount": len(invalidRoots),
+				"newHeadRoot":  fmt.Sprintf("%#x", bytesutil.Trunc(r[:])),
 			}).Warn("Pruned invalid blocks")
-			return pid, invalidBlock{error: ErrInvalidPayload, root: arg.headRoot, invalidAncestorRoots: invalidRoots}
+			return pid, invalidBlock{error: ErrInvalidPayload, root: arg.headRoot}

 		default:
 			log.WithError(err).Error(ErrUndefinedExecutionEngineError)
@@ -148,11 +145,10 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 		log.WithError(err).Error("Could not set head root to valid")
 		return nil, nil
 	}
-	// If the forkchoice update call has an attribute, update the proposer payload ID cache.
-	if hasAttr && payloadID != nil {
+	if hasAttr && payloadID != nil { // If the forkchoice update call has an attribute, update the proposer payload ID cache.
 		var pId [8]byte
 		copy(pId[:], payloadID[:])
-		s.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(nextSlot, proposerId, pId, arg.headRoot)
+		s.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(nextSlot, proposerId, pId)
 	} else if hasAttr && payloadID == nil {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
@@ -179,10 +175,10 @@ func (s *Service) getPayloadHash(ctx context.Context, root []byte) ([32]byte, er
 	return bytesutil.ToBytes32(payload.BlockHash()), nil
 }

-// notifyNewPayload signals execution engine on a new payload.
+// notifyForkchoiceUpdate signals execution engine on a new payload.
 // It returns true if the EL has returned VALID for the block
 func (s *Service) notifyNewPayload(ctx context.Context, postStateVersion int,
-	postStateHeader interfaces.ExecutionData, blk interfaces.SignedBeaconBlock) (bool, error) {
+	postStateHeader *enginev1.ExecutionPayloadHeader, blk interfaces.SignedBeaconBlock) (bool, error) {
 	ctx, span := trace.StartSpan(ctx, "blockChain.notifyNewPayload")
 	defer span.End()

@@ -191,7 +187,7 @@ func (s *Service) notifyNewPayload(ctx context.Context, postStateVersion int,
 	if blocks.IsPreBellatrixVersion(postStateVersion) {
 		return true, nil
 	}
-	if err := consensusblocks.BeaconBlockIsNil(blk); err != nil {
+	if err := wrapper.BeaconBlockIsNil(blk); err != nil {
 		return false, err
 	}
 	body := blk.Block().Body()
@@ -211,20 +207,20 @@ func (s *Service) notifyNewPayload(ctx context.Context, postStateVersion int,
 	case nil:
 		newPayloadValidNodeCount.Inc()
 		return true, nil
-	case execution.ErrAcceptedSyncingPayloadStatus:
+	case powchain.ErrAcceptedSyncingPayloadStatus:
 		newPayloadOptimisticNodeCount.Inc()
 		log.WithFields(logrus.Fields{
 			"slot":             blk.Block().Slot(),
 			"payloadBlockHash": fmt.Sprintf("%#x", bytesutil.Trunc(payload.BlockHash())),
 		}).Info("Called new payload with optimistic block")
-		return false, nil
-	case execution.ErrInvalidPayloadStatus:
+		return false, s.optimisticCandidateBlock(ctx, blk.Block())
+	case powchain.ErrInvalidPayloadStatus:
 		newPayloadInvalidNodeCount.Inc()
 		root, err := blk.Block().HashTreeRoot()
 		if err != nil {
 			return false, err
 		}
-		invalidRoots, err := s.ForkChoicer().SetOptimisticToInvalid(ctx, root, blk.Block().ParentRoot(), bytesutil.ToBytes32(lastValidHash))
+		invalidRoots, err := s.ForkChoicer().SetOptimisticToInvalid(ctx, root, bytesutil.ToBytes32(blk.Block().ParentRoot()), bytesutil.ToBytes32(lastValidHash))
 		if err != nil {
 			return false, err
 		}
@@ -232,15 +228,12 @@ func (s *Service) notifyNewPayload(ctx context.Context, postStateVersion int,
 			return false, err
 		}
 		log.WithFields(logrus.Fields{
-			"slot":                 blk.Block().Slot(),
-			"blockRoot":            fmt.Sprintf("%#x", root),
-			"invalidChildrenCount": len(invalidRoots),
+			"slot":         blk.Block().Slot(),
+			"blockRoot":    fmt.Sprintf("%#x", root),
+			"invalidCount": len(invalidRoots),
 		}).Warn("Pruned invalid blocks")
-		return false, invalidBlock{
-			invalidAncestorRoots: invalidRoots,
-			error:                ErrInvalidPayload,
-		}
-	case execution.ErrInvalidBlockHashPayloadStatus:
+		return false, ErrInvalidPayload
+	case powchain.ErrInvalidBlockHashPayloadStatus:
 		newPayloadInvalidNodeCount.Inc()
 		return false, ErrInvalidBlockHashPayloadStatus
 	default:
@@ -248,27 +241,54 @@ func (s *Service) notifyNewPayload(ctx context.Context, postStateVersion int,
 	}
 }

+// optimisticCandidateBlock returns an error if this block can't be optimistically synced.
+// It replaces boolean in spec code with `errNotOptimisticCandidate`.
+//
+// Spec pseudocode definition:
+// def is_optimistic_candidate_block(opt_store: OptimisticStore, current_slot: Slot, block: BeaconBlock) -> bool:
+//    if is_execution_block(opt_store.blocks[block.parent_root]):
+//        return True
+//
+//    if block.slot + SAFE_SLOTS_TO_IMPORT_OPTIMISTICALLY <= current_slot:
+//        return True
+//
+//    return False
+func (s *Service) optimisticCandidateBlock(ctx context.Context, blk interfaces.BeaconBlock) error {
+	if blk.Slot()+params.BeaconConfig().SafeSlotsToImportOptimistically <= s.CurrentSlot() {
+		return nil
+	}
+	parent, err := s.getBlock(ctx, bytesutil.ToBytes32(blk.ParentRoot()))
+	if err != nil {
+		return err
+	}
+	parentIsExecutionBlock, err := blocks.IsExecutionBlock(parent.Block().Body())
+	if err != nil {
+		return err
+	}
+	if parentIsExecutionBlock {
+		return nil
+	}
+
+	return errNotOptimisticCandidate
+}
+
 // getPayloadAttributes returns the payload attributes for the given state and slot.
 // The attribute is required to initiate a payload build process in the context of an `engine_forkchoiceUpdated` call.
-func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState, slot types.Slot) (bool, payloadattribute.Attributer, types.ValidatorIndex) {
-	emptyAttri := payloadattribute.EmptyWithVersion(st.Version())
-	// Root is `[32]byte{}` since we are retrieving proposer ID of a given slot. During insertion at assignment the root was not known.
-	proposerID, _, ok := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(slot, [32]byte{} /* root */)
+func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState, slot types.Slot) (bool, *enginev1.PayloadAttributes, types.ValidatorIndex, error) {
+	proposerID, _, ok := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(slot)
 	if !ok { // There's no need to build attribute if there is no proposer for slot.
-		return false, emptyAttri, 0
+		return false, nil, 0, nil
 	}

 	// Get previous randao.
 	st = st.Copy()
 	st, err := transition.ProcessSlotsIfPossible(ctx, st, slot)
 	if err != nil {
-		log.WithError(err).Error("Could not process slots to get payload attribute")
-		return false, emptyAttri, 0
+		return false, nil, 0, err
 	}
 	prevRando, err := helpers.RandaoMix(st, time.CurrentEpoch(st))
 	if err != nil {
-		log.WithError(err).Error("Could not get randao mix to get payload attribute")
-		return false, emptyAttri, 0
+		return false, nil, 0, nil
 	}

 	// Get fee recipient.
@@ -286,8 +306,7 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 				"Please refer to our documentation for instructions")
 		}
 	case err != nil:
-		log.WithError(err).Error("Could not get fee recipient to get payload attribute")
-		return false, emptyAttri, 0
+		return false, nil, 0, errors.Wrap(err, "could not get fee recipient in db")
 	default:
 		feeRecipient = recipient
 	}
@@ -295,44 +314,14 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 	// Get timestamp.
 	t, err := slots.ToTime(uint64(s.genesisTime.Unix()), slot)
 	if err != nil {
-		log.WithError(err).Error("Could not get timestamp to get payload attribute")
-		return false, emptyAttri, 0
+		return false, nil, 0, err
 	}
-
-	var attr payloadattribute.Attributer
-	switch st.Version() {
-	case version.Capella:
-		withdrawals, err := st.ExpectedWithdrawals()
-		if err != nil {
-			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
-			return false, emptyAttri, 0
-		}
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV2{
-			Timestamp:             uint64(t.Unix()),
-			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: feeRecipient.Bytes(),
-			Withdrawals:           withdrawals,
-		})
-		if err != nil {
-			log.WithError(err).Error("Could not get payload attribute")
-			return false, emptyAttri, 0
-		}
-	case version.Bellatrix:
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributes{
-			Timestamp:             uint64(t.Unix()),
-			PrevRandao:            prevRando,
-			SuggestedFeeRecipient: feeRecipient.Bytes(),
-		})
-		if err != nil {
-			log.WithError(err).Error("Could not get payload attribute")
-			return false, emptyAttri, 0
-		}
-	default:
-		log.WithField("version", st.Version()).Error("Could not get payload attribute due to unknown state version")
-		return false, emptyAttri, 0
+	attr := &enginev1.PayloadAttributes{
+		Timestamp:             uint64(t.Unix()),
+		PrevRandao:            prevRando,
+		SuggestedFeeRecipient: feeRecipient.Bytes(),
 	}
-
-	return true, attr, proposerID
+	return true, attr, proposerID, nil
 }

 // removeInvalidBlockAndState removes the invalid block and its corresponding state from the cache and DB.
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -7,94 +7,32 @@ import (

 	"github.com/ethereum/go-ethereum/common"
 	gethtypes "github.com/ethereum/go-ethereum/core/types"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/blocks"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/execution"
-	mockExecution "github.com/prysmaticlabs/prysm/v3/beacon-chain/execution/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	bstate "github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	state_native "github.com/prysmaticlabs/prysm/v3/beacon-chain/state/state-native"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	consensusblocks "github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	v1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
+	mockPOW "github.com/prysmaticlabs/prysm/beacon-chain/powchain/testing"
+	bstate "github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

-func Test_NotifyForkchoiceUpdate_GetPayloadAttrErrorCanContinue(t *testing.T) {
-	ctx := context.Background()
-	beaconDB := testDB.SetupDB(t)
-	altairBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockAltair())
-	altairBlkRoot, err := altairBlk.Block().HashTreeRoot()
-	require.NoError(t, err)
-	bellatrixBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockBellatrix())
-	bellatrixBlkRoot, err := bellatrixBlk.Block().HashTreeRoot()
-	require.NoError(t, err)
-	fcs := doublylinkedtree.New()
-	opts := []Option{
-		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
-		WithForkChoiceStore(fcs),
-		WithProposerIdsCache(cache.NewProposerPayloadIDsCache()),
-	}
-	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
-	st, _ := util.DeterministicGenesisState(t, 10)
-	service.head = &head{
-		state: st,
-	}
-
-	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	state, blkRoot, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
-	require.NoError(t, err)
-	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
-	state, blkRoot, err = prepareForkchoiceState(ctx, 1, altairBlkRoot, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
-	require.NoError(t, err)
-	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
-	state, blkRoot, err = prepareForkchoiceState(ctx, 2, bellatrixBlkRoot, altairBlkRoot, params.BeaconConfig().ZeroHash, ojc, ofc)
-	require.NoError(t, err)
-	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
-
-	b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
-		Body: &ethpb.BeaconBlockBodyBellatrix{
-			ExecutionPayload: &v1.ExecutionPayload{},
-		},
-	})
-	require.NoError(t, err)
-
-	pid := &v1.PayloadIDBytes{1}
-	service.cfg.ExecutionEngineCaller = &mockExecution.EngineClient{PayloadIDBytes: pid}
-	st, _ = util.DeterministicGenesisState(t, 1)
-	require.NoError(t, beaconDB.SaveState(ctx, st, bellatrixBlkRoot))
-	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bellatrixBlkRoot))
-
-	// Intentionally generate a bad state such that `hash_tree_root` fails during `process_slot`
-	s, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
-	require.NoError(t, err)
-	arg := &notifyForkchoiceUpdateArg{
-		headState: s,
-		headRoot:  [32]byte{},
-		headBlock: b,
-	}
-
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(1, 0, [8]byte{}, [32]byte{})
-	got, err := service.notifyForkchoiceUpdate(ctx, arg)
-	require.NoError(t, err)
-	require.DeepEqual(t, got, pid) // We still get a payload ID even though the state is bad. This means it returns until the end.
-}
-
 func Test_NotifyForkchoiceUpdate(t *testing.T) {
+	params.BeaconConfig().SafeSlotsToImportOptimistically = 0
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	altairBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockAltair())
@@ -103,20 +41,19 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 	bellatrixBlk := util.SaveBlock(t, ctx, beaconDB, util.NewBeaconBlockBellatrix())
 	bellatrixBlkRoot, err := bellatrixBlk.Block().HashTreeRoot()
 	require.NoError(t, err)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 		WithProposerIdsCache(cache.NewProposerPayloadIDsCache()),
 	}
 	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
 	st, _ := util.DeterministicGenesisState(t, 10)
 	service.head = &head{
 		state: st,
 	}
-
+	require.NoError(t, err)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	state, blkRoot, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
@@ -141,7 +78,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		{
 			name: "phase0 block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}})
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}})
 				require.NoError(t, err)
 				return b
 			}(),
@@ -149,7 +86,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		{
 			name: "altair block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockAltair{Body: &ethpb.BeaconBlockBodyAltair{}})
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlockAltair{Body: &ethpb.BeaconBlockBodyAltair{}})
 				require.NoError(t, err)
 				return b
 			}(),
@@ -157,7 +94,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		{
 			name: "not execution block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{
 							ParentHash:    make([]byte, fieldparams.RootLength),
@@ -178,7 +115,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		{
 			name: "happy case: finalized root is altair block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
@@ -192,7 +129,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		{
 			name: "happy case: finalized root is bellatrix block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
@@ -206,7 +143,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 		{
 			name: "forkchoice updated with optimistic block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
@@ -214,14 +151,14 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 				require.NoError(t, err)
 				return b
 			}(),
-			newForkchoiceErr: execution.ErrAcceptedSyncingPayloadStatus,
+			newForkchoiceErr: powchain.ErrAcceptedSyncingPayloadStatus,
 			finalizedRoot:    bellatrixBlkRoot,
 			justifiedRoot:    bellatrixBlkRoot,
 		},
 		{
 			name: "forkchoice updated with invalid block",
 			blk: func() interfaces.BeaconBlock {
-				b, err := consensusblocks.NewBeaconBlock(&ethpb.BeaconBlockBellatrix{
+				b, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlockBellatrix{
 					Body: &ethpb.BeaconBlockBodyBellatrix{
 						ExecutionPayload: &v1.ExecutionPayload{},
 					},
@@ -229,7 +166,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 				require.NoError(t, err)
 				return b
 			}(),
-			newForkchoiceErr: execution.ErrInvalidPayloadStatus,
+			newForkchoiceErr: powchain.ErrInvalidPayloadStatus,
 			finalizedRoot:    bellatrixBlkRoot,
 			justifiedRoot:    bellatrixBlkRoot,
 			headRoot:         [32]byte{'a'},
@@ -239,7 +176,7 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {

 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			service.cfg.ExecutionEngineCaller = &mockExecution.EngineClient{ErrForkchoiceUpdated: tt.newForkchoiceErr}
+			service.cfg.ExecutionEngineCaller = &mockPOW.EngineClient{ErrForkchoiceUpdated: tt.newForkchoiceErr}
 			st, _ := util.DeterministicGenesisState(t, 1)
 			require.NoError(t, beaconDB.SaveState(ctx, st, tt.finalizedRoot))
 			require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, tt.finalizedRoot))
@@ -262,7 +199,22 @@ func Test_NotifyForkchoiceUpdate(t *testing.T) {
 	}
 }

-func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
+//
+//
+//  A <- B <- C <- D
+//       \
+//         ---------- E <- F
+//                     \
+//                       ------ G
+// D is the current head, attestations for F and G come late, both are invalid.
+// We switch recursively to F then G and finally to D.
+//
+// We test:
+// 1. forkchoice removes blocks F and G from the forkchoice implementation
+// 2. forkchoice removes the weights of these blocks
+// 3. the blockchain package calls fcu to obtain heads G -> F -> D.
+
+func Test_NotifyForkchoiceUpdateRecursive_Protoarray(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)

@@ -280,8 +232,6 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 	require.NoError(t, err)

 	bc := util.NewBeaconBlockBellatrix()
-	pc := [32]byte{'C'}
-	bc.Block.Body.ExecutionPayload.BlockHash = pc[:]
 	bc.Block.Body.ExecutionPayload.BlockNumber = 3
 	wbc := util.SaveBlock(t, ctx, beaconDB, bc)
 	brc, err := wbc.Block().HashTreeRoot()
@@ -291,14 +241,39 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 	pd := [32]byte{'D'}
 	bd.Block.Body.ExecutionPayload.BlockHash = pd[:]
 	bd.Block.Body.ExecutionPayload.BlockNumber = 4
-	bd.Block.ParentRoot = brc[:]
 	wbd := util.SaveBlock(t, ctx, beaconDB, bd)
 	brd, err := wbd.Block().HashTreeRoot()
 	require.NoError(t, err)

+	be := util.NewBeaconBlockBellatrix()
+	pe := [32]byte{'E'}
+	be.Block.Body.ExecutionPayload.BlockHash = pe[:]
+	be.Block.Body.ExecutionPayload.BlockNumber = 5
+	wbe := util.SaveBlock(t, ctx, beaconDB, be)
+	bre, err := wbe.Block().HashTreeRoot()
+	require.NoError(t, err)
+
+	bf := util.NewBeaconBlockBellatrix()
+	pf := [32]byte{'F'}
+	bf.Block.Body.ExecutionPayload.BlockHash = pf[:]
+	bf.Block.Body.ExecutionPayload.BlockNumber = 6
+	bf.Block.ParentRoot = bre[:]
+	wbf := util.SaveBlock(t, ctx, beaconDB, bf)
+	brf, err := wbf.Block().HashTreeRoot()
+	require.NoError(t, err)
+
+	bg := util.NewBeaconBlockBellatrix()
+	bg.Block.Body.ExecutionPayload.BlockNumber = 7
+	pg := [32]byte{'G'}
+	bg.Block.Body.ExecutionPayload.BlockHash = pg[:]
+	bg.Block.ParentRoot = bre[:]
+	wbg := util.SaveBlock(t, ctx, beaconDB, bg)
+	brg, err := wbg.Block().HashTreeRoot()
+	require.NoError(t, err)
+
 	// Insert blocks into forkchoice
 	service := setupBeaconChain(t, beaconDB)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	service.cfg.ForkChoiceStore = fcs
 	service.cfg.ProposerSlotIndexCache = cache.NewProposerPayloadIDsCache()

@@ -318,9 +293,29 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 	state, blkRoot, err = prepareForkchoiceState(ctx, 4, brd, brc, [32]byte{'D'}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
+	state, blkRoot, err = prepareForkchoiceState(ctx, 5, bre, brb, [32]byte{'E'}, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
+	state, blkRoot, err = prepareForkchoiceState(ctx, 6, brf, bre, [32]byte{'F'}, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
+	state, blkRoot, err = prepareForkchoiceState(ctx, 7, brg, bre, [32]byte{'G'}, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))

-	// Prepare Engine Mock to return invalid LVH =  nil
-	service.cfg.ExecutionEngineCaller = &mockExecution.EngineClient{ErrForkchoiceUpdated: execution.ErrInvalidPayloadStatus, OverrideValidHash: [32]byte{'C'}}
+	// Insert Attestations to D, F and G so that they have higher weight than D
+	// Ensure G is head
+	fcs.ProcessAttestation(ctx, []uint64{0}, brd, 1)
+	fcs.ProcessAttestation(ctx, []uint64{1}, brf, 1)
+	fcs.ProcessAttestation(ctx, []uint64{2}, brg, 1)
+	jc := &forkchoicetypes.Checkpoint{Epoch: 0, Root: bra}
+	require.NoError(t, fcs.UpdateJustifiedCheckpoint(jc))
+	headRoot, err := fcs.Head(ctx, []uint64{50, 100, 200})
+	require.NoError(t, err)
+	require.Equal(t, brg, headRoot)
+
+	// Prepare Engine Mock to return invalid unless head is D, LVH =  E
+	service.cfg.ExecutionEngineCaller = &mockPOW.EngineClient{ErrForkchoiceUpdated: powchain.ErrInvalidPayloadStatus, ForkChoiceUpdatedResp: pe[:], OverrideValidHash: [32]byte{'D'}}
 	st, _ := util.DeterministicGenesisState(t, 1)
 	service.head = &head{
 		state: st,
@@ -331,14 +326,22 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bra))
 	a := &notifyForkchoiceUpdateArg{
 		headState: st,
-		headBlock: wbd.Block(),
-		headRoot:  brd,
+		headBlock: wbg.Block(),
+		headRoot:  brg,
 	}
 	_, err = service.notifyForkchoiceUpdate(ctx, a)
 	require.Equal(t, true, IsInvalidBlock(err))
-	require.Equal(t, brd, InvalidBlockRoot(err))
-	require.Equal(t, brd, InvalidAncestorRoots(err)[0])
-	require.Equal(t, 1, len(InvalidAncestorRoots(err)))
+	require.Equal(t, brf, InvalidBlockRoot(err))
+
+	// Ensure Head is D
+	headRoot, err = fcs.Head(ctx, service.justifiedBalances.balances)
+	require.NoError(t, err)
+	require.Equal(t, brd, headRoot)
+
+	// Ensure F and G where removed but their parent E wasn't
+	require.Equal(t, false, fcs.HasNode(brf))
+	require.Equal(t, false, fcs.HasNode(brg))
+	require.Equal(t, true, fcs.HasNode(bre))
 }

 //
@@ -457,7 +460,7 @@ func Test_NotifyForkchoiceUpdateRecursive_DoublyLinkedTree(t *testing.T) {
 	require.Equal(t, brg, headRoot)

 	// Prepare Engine Mock to return invalid unless head is D, LVH =  E
-	service.cfg.ExecutionEngineCaller = &mockExecution.EngineClient{ErrForkchoiceUpdated: execution.ErrInvalidPayloadStatus, ForkChoiceUpdatedResp: pe[:], OverrideValidHash: [32]byte{'D'}}
+	service.cfg.ExecutionEngineCaller = &mockPOW.EngineClient{ErrForkchoiceUpdated: powchain.ErrInvalidPayloadStatus, ForkChoiceUpdatedResp: pe[:], OverrideValidHash: [32]byte{'D'}}
 	st, _ := util.DeterministicGenesisState(t, 1)
 	service.head = &head{
 		state: st,
@@ -493,10 +496,10 @@ func Test_NotifyNewPayload(t *testing.T) {

 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 	phase0State, _ := util.DeterministicGenesisState(t, 1)
@@ -507,7 +510,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 			Body: &ethpb.BeaconBlockBodyAltair{},
 		},
 	}
-	altairBlk, err := consensusblocks.NewSignedBeaconBlock(a)
+	altairBlk, err := wrapper.WrappedSignedBeaconBlock(a)
 	require.NoError(t, err)
 	blk := &ethpb.SignedBeaconBlockBellatrix{
 		Block: &ethpb.BeaconBlockBellatrix{
@@ -527,7 +530,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 			},
 		},
 	}
-	bellatrixBlk, err := consensusblocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlockBellatrix(blk))
+	bellatrixBlk, err := wrapper.WrappedSignedBeaconBlock(util.HydrateSignedBeaconBlockBellatrix(blk))
 	require.NoError(t, err)
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -573,14 +576,14 @@ func Test_NotifyNewPayload(t *testing.T) {
 			name:           "new payload with optimistic block",
 			postState:      bellatrixState,
 			blk:            bellatrixBlk,
-			newPayloadErr:  execution.ErrAcceptedSyncingPayloadStatus,
+			newPayloadErr:  powchain.ErrAcceptedSyncingPayloadStatus,
 			isValidPayload: false,
 		},
 		{
 			name:           "new payload with invalid block",
 			postState:      bellatrixState,
 			blk:            bellatrixBlk,
-			newPayloadErr:  execution.ErrInvalidPayloadStatus,
+			newPayloadErr:  powchain.ErrInvalidPayloadStatus,
 			errString:      ErrInvalidPayload.Error(),
 			isValidPayload: false,
 			invalidBlock:   true,
@@ -604,7 +607,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 						},
 					},
 				}
-				b, err := consensusblocks.NewSignedBeaconBlock(blk)
+				b, err := wrapper.WrappedSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
 			}(),
@@ -630,7 +633,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 						},
 					},
 				}
-				b, err := consensusblocks.NewSignedBeaconBlock(blk)
+				b, err := wrapper.WrappedSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
 			}(),
@@ -649,7 +652,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 						},
 					},
 				}
-				b, err := consensusblocks.NewSignedBeaconBlock(blk)
+				b, err := wrapper.WrappedSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
 			}(),
@@ -668,7 +671,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 						},
 					},
 				}
-				b, err := consensusblocks.NewSignedBeaconBlock(blk)
+				b, err := wrapper.WrappedSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
 			}(),
@@ -688,7 +691,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 						},
 					},
 				}
-				b, err := consensusblocks.NewSignedBeaconBlock(blk)
+				b, err := wrapper.WrappedSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
 			}(),
@@ -698,7 +701,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			e := &mockExecution.EngineClient{ErrNewPayload: tt.newPayloadErr, BlockByHashMap: map[[32]byte]*v1.ExecutionBlock{}}
+			e := &mockPOW.EngineClient{ErrNewPayload: tt.newPayloadErr, BlockByHashMap: map[[32]byte]*v1.ExecutionBlock{}}
 			e.BlockByHashMap[[32]byte{'a'}] = &v1.ExecutionBlock{
 				Header: gethtypes.Header{
 					ParentHash: common.BytesToHash([]byte("b")),
@@ -713,7 +716,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 			}
 			service.cfg.ExecutionEngineCaller = e
 			root := [32]byte{'a'}
-			state, blkRoot, err := prepareForkchoiceState(ctx, 0, root, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+			state, blkRoot, err := prepareForkchoiceState(ctx, 0, root, root, params.BeaconConfig().ZeroHash, ojc, ofc)
 			require.NoError(t, err)
 			require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 			postVersion, postHeader, err := getStateVersionAndPayload(tt.postState)
@@ -739,10 +742,10 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 	bellatrixState, _ := util.DeterministicGenesisStateBellatrix(t, 2)
@@ -755,11 +758,11 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 			},
 		},
 	}
-	bellatrixBlk, err := consensusblocks.NewSignedBeaconBlock(blk)
+	bellatrixBlk, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	e := &mockExecution.EngineClient{BlockByHashMap: map[[32]byte]*v1.ExecutionBlock{}}
+	e := &mockPOW.EngineClient{BlockByHashMap: map[[32]byte]*v1.ExecutionBlock{}}
 	e.BlockByHashMap[[32]byte{'a'}] = &v1.ExecutionBlock{
 		Header: gethtypes.Header{
 			ParentHash: common.BytesToHash([]byte("b")),
@@ -780,86 +783,194 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	require.Equal(t, true, validated)
 }

+func Test_IsOptimisticCandidateBlock(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	params.OverrideBeaconConfig(params.MainnetConfig())
+
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	fcs := protoarray.New()
+	opts := []Option{
+		WithDatabase(beaconDB),
+		WithStateGen(stategen.New(beaconDB)),
+		WithForkChoiceStore(fcs),
+	}
+
+	service, err := NewService(ctx, opts...)
+	require.NoError(t, err)
+
+	params.BeaconConfig().SafeSlotsToImportOptimistically = 128
+	service.genesisTime = time.Now().Add(-time.Second * 12 * 2 * 128)
+
+	parentBlk := util.NewBeaconBlockBellatrix()
+	wrappedParentBlock, err := wrapper.WrappedSignedBeaconBlock(parentBlk)
+	require.NoError(t, err)
+	parentRoot, err := wrappedParentBlock.Block().HashTreeRoot()
+	require.NoError(t, err)
+
+	tests := []struct {
+		name      string
+		blk       interfaces.BeaconBlock
+		justified interfaces.SignedBeaconBlock
+		err       error
+	}{
+		{
+			name: "deep block",
+			blk: func(tt *testing.T) interfaces.BeaconBlock {
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Slot = 1
+				blk.Block.ParentRoot = parentRoot[:]
+				wr, err := wrapper.WrappedBeaconBlock(blk.Block)
+				require.NoError(tt, err)
+				return wr
+			}(t),
+			justified: func(tt *testing.T) interfaces.SignedBeaconBlock {
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Slot = 32
+				blk.Block.ParentRoot = parentRoot[:]
+				wr, err := wrapper.WrappedSignedBeaconBlock(blk)
+				require.NoError(tt, err)
+				return wr
+			}(t),
+			err: nil,
+		},
+		{
+			name: "shallow block, Altair justified chkpt",
+			blk: func(tt *testing.T) interfaces.BeaconBlock {
+				blk := util.NewBeaconBlockAltair()
+				blk.Block.Slot = 200
+				blk.Block.ParentRoot = parentRoot[:]
+				wr, err := wrapper.WrappedBeaconBlock(blk.Block)
+				require.NoError(tt, err)
+				return wr
+			}(t),
+			justified: func(tt *testing.T) interfaces.SignedBeaconBlock {
+				blk := util.NewBeaconBlockAltair()
+				blk.Block.Slot = 32
+				blk.Block.ParentRoot = parentRoot[:]
+				wr, err := wrapper.WrappedSignedBeaconBlock(blk)
+				require.NoError(tt, err)
+				return wr
+			}(t),
+			err: errNotOptimisticCandidate,
+		},
+		{
+			name: "shallow block, Bellatrix justified chkpt without execution",
+			blk: func(tt *testing.T) interfaces.BeaconBlock {
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Slot = 200
+				blk.Block.ParentRoot = parentRoot[:]
+				wr, err := wrapper.WrappedBeaconBlock(blk.Block)
+				require.NoError(tt, err)
+				return wr
+			}(t),
+			justified: func(tt *testing.T) interfaces.SignedBeaconBlock {
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Slot = 32
+				blk.Block.ParentRoot = parentRoot[:]
+				wr, err := wrapper.WrappedSignedBeaconBlock(blk)
+				require.NoError(tt, err)
+				return wr
+			}(t),
+			err: errNotOptimisticCandidate,
+		},
+	}
+	for _, tt := range tests {
+		require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, tt.justified))
+		require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wrappedParentBlock))
+
+		err = service.optimisticCandidateBlock(ctx, tt.blk)
+		if tt.err != nil {
+			require.Equal(t, tt.err.Error(), err.Error())
+		} else {
+			require.NoError(t, err)
+		}
+	}
+}
+
+func Test_IsOptimisticShallowExecutionParent(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	params.OverrideBeaconConfig(params.MainnetConfig())
+
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	opts := []Option{
+		WithDatabase(beaconDB),
+		WithStateGen(stategen.New(beaconDB)),
+	}
+
+	service, err := NewService(ctx, opts...)
+	require.NoError(t, err)
+
+	params.BeaconConfig().SafeSlotsToImportOptimistically = 128
+	service.genesisTime = time.Now().Add(-time.Second * 12 * 2 * 128)
+	payload := &v1.ExecutionPayload{
+		ParentHash:    make([]byte, 32),
+		FeeRecipient:  make([]byte, 20),
+		StateRoot:     make([]byte, 32),
+		ReceiptsRoot:  make([]byte, 32),
+		LogsBloom:     make([]byte, 256),
+		PrevRandao:    make([]byte, 32),
+		BaseFeePerGas: bytesutil.PadTo([]byte{1, 2, 3, 4}, fieldparams.RootLength),
+		BlockHash:     make([]byte, 32),
+		BlockNumber:   100,
+	}
+	body := &ethpb.BeaconBlockBodyBellatrix{ExecutionPayload: payload}
+	b := &ethpb.BeaconBlockBellatrix{Body: body, Slot: 200}
+	rawSigned := &ethpb.SignedBeaconBlockBellatrix{Block: b}
+	blk := util.HydrateSignedBeaconBlockBellatrix(rawSigned)
+	wr := util.SaveBlock(t, ctx, service.cfg.BeaconDB, blk)
+	blkRoot, err := wr.Block().HashTreeRoot()
+	require.NoError(t, err)
+
+	childBlock := util.NewBeaconBlockBellatrix()
+	childBlock.Block.ParentRoot = blkRoot[:]
+	// shallow block
+	childBlock.Block.Slot = 201
+	wrappedChild := util.SaveBlock(t, ctx, service.cfg.BeaconDB, childBlock)
+	err = service.optimisticCandidateBlock(ctx, wrappedChild.Block())
+	require.NoError(t, err)
+}
+
 func Test_GetPayloadAttribute(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, doublylinkedtree.New())),
+		WithStateGen(stategen.New(beaconDB)),
 		WithProposerIdsCache(cache.NewProposerPayloadIDsCache()),
 	}

 	// Cache miss
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	st, _ := util.DeterministicGenesisStateBellatrix(t, 1)
-	hasPayload, _, vId := service.getPayloadAttribute(ctx, st, 0)
+	hasPayload, _, vId, err := service.getPayloadAttribute(ctx, nil, 0)
+	require.NoError(t, err)
 	require.Equal(t, false, hasPayload)
 	require.Equal(t, types.ValidatorIndex(0), vId)

 	// Cache hit, advance state, no fee recipient
 	suggestedVid := types.ValidatorIndex(1)
 	slot := types.Slot(1)
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{})
+	st, _ := util.DeterministicGenesisState(t, 1)
 	hook := logTest.NewGlobal()
-	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, slot)
+	hasPayload, attr, vId, err := service.getPayloadAttribute(ctx, st, slot)
+	require.NoError(t, err)
 	require.Equal(t, true, hasPayload)
 	require.Equal(t, suggestedVid, vId)
-	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient).String())
 	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")

 	// Cache hit, advance state, has fee recipient
 	suggestedAddr := common.HexToAddress("123")
 	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []types.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
-	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot)
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{})
+	hasPayload, attr, vId, err = service.getPayloadAttribute(ctx, st, slot)
+	require.NoError(t, err)
 	require.Equal(t, true, hasPayload)
 	require.Equal(t, suggestedVid, vId)
-	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
-}
-
-func Test_GetPayloadAttributeV2(t *testing.T) {
-	ctx := context.Background()
-	beaconDB := testDB.SetupDB(t)
-	opts := []Option{
-		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, doublylinkedtree.New())),
-		WithProposerIdsCache(cache.NewProposerPayloadIDsCache()),
-	}
-
-	// Cache miss
-	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
-	st, _ := util.DeterministicGenesisStateCapella(t, 1)
-	hasPayload, _, vId := service.getPayloadAttribute(ctx, st, 0)
-	require.Equal(t, false, hasPayload)
-	require.Equal(t, types.ValidatorIndex(0), vId)
-
-	// Cache hit, advance state, no fee recipient
-	suggestedVid := types.ValidatorIndex(1)
-	slot := types.Slot(1)
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
-	hook := logTest.NewGlobal()
-	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, slot)
-	require.Equal(t, true, hasPayload)
-	require.Equal(t, suggestedVid, vId)
-	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
-	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")
-	a, err := attr.Withdrawals()
-	require.NoError(t, err)
-	require.Equal(t, 0, len(a))
-
-	// Cache hit, advance state, has fee recipient
-	suggestedAddr := common.HexToAddress("123")
-	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []types.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
-	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot)
-	require.Equal(t, true, hasPayload)
-	require.Equal(t, suggestedVid, vId)
-	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
-	a, err = attr.Withdrawals()
-	require.NoError(t, err)
-	require.Equal(t, 0, len(a))
+	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient))
 }

 func Test_UpdateLastValidatedCheckpoint(t *testing.T) {
@@ -868,8 +979,8 @@ func Test_UpdateLastValidatedCheckpoint(t *testing.T) {

 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
+	stateGen := stategen.New(beaconDB)
 	fcs := doublylinkedtree.New()
-	stateGen := stategen.New(beaconDB, fcs)
 	opts := []Option{
 		WithDatabase(beaconDB),
 		WithStateGen(stateGen),
@@ -877,7 +988,7 @@ func Test_UpdateLastValidatedCheckpoint(t *testing.T) {
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	var genesisStateRoot [32]byte
+	genesisStateRoot := [32]byte{}
 	genesisBlk := blocks.NewGenesisBlock(genesisStateRoot[:])
 	util.SaveBlock(t, ctx, beaconDB, genesisBlk)
 	genesisRoot, err := genesisBlk.Block.HashTreeRoot()
@@ -965,28 +1076,15 @@ func Test_UpdateLastValidatedCheckpoint(t *testing.T) {
 	require.Equal(t, false, optimistic)
 	require.DeepEqual(t, validCheckpoint.Root, cp.Root)
 	require.Equal(t, validCheckpoint.Epoch, cp.Epoch)
-
-	// Checkpoint with a lower epoch
-	oldCp, err := service.cfg.BeaconDB.FinalizedCheckpoint(ctx)
-	require.NoError(t, err)
-	invalidCp := &ethpb.Checkpoint{
-		Epoch: oldCp.Epoch - 1,
-	}
-	// Nothing should happen as we no-op on an invalid checkpoint.
-	require.NoError(t, service.updateFinalized(ctx, invalidCp))
-	got, err := service.cfg.BeaconDB.FinalizedCheckpoint(ctx)
-	require.NoError(t, err)
-	require.DeepEqual(t, oldCp, got)
 }

 func TestService_removeInvalidBlockAndState(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fc := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fc)),
-		WithForkChoiceStore(fc),
+		WithStateGen(stategen.New(beaconDB)),
+		WithForkChoiceStore(protoarray.New()),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -1035,11 +1133,10 @@ func TestService_removeInvalidBlockAndState(t *testing.T) {
 func TestService_getPayloadHash(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fc := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fc)),
-		WithForkChoiceStore(fc),
+		WithStateGen(stategen.New(beaconDB)),
+		WithForkChoiceStore(protoarray.New()),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -1050,7 +1147,7 @@ func TestService_getPayloadHash(t *testing.T) {
 	b := util.NewBeaconBlock()
 	r, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	wsb, err := consensusblocks.NewSignedBeaconBlock(b)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
 	require.NoError(t, err)
 	require.NoError(t, service.saveInitSyncBlock(ctx, r, wsb))

@@ -1063,7 +1160,7 @@ func TestService_getPayloadHash(t *testing.T) {
 	bb.Block.Body.ExecutionPayload.BlockHash = h[:]
 	r, err = b.Block.HashTreeRoot()
 	require.NoError(t, err)
-	wsb, err = consensusblocks.NewSignedBeaconBlock(bb)
+	wsb, err = wrapper.WrappedSignedBeaconBlock(bb)
 	require.NoError(t, err)
 	require.NoError(t, service.saveInitSyncBlock(ctx, r, wsb))

--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -6,21 +6,19 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v3/math"
-	ethpbv1 "github.com/prysmaticlabs/prysm/v3/proto/eth/v1"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpbv1 "github.com/prysmaticlabs/prysm/proto/eth/v1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -52,6 +50,7 @@ func (s *Service) UpdateAndSaveHeadWithBalances(ctx context.Context) error {

 // This defines the current chain service's view of head.
 type head struct {
+	slot  types.Slot                   // current head slot.
 	root  [32]byte                     // current head root.
 	block interfaces.SignedBeaconBlock // current head block.
 	state state.BeaconState            // current head state.
@@ -75,7 +74,7 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 	if newHeadRoot == oldHeadRoot {
 		return nil
 	}
-	if err := blocks.BeaconBlockIsNil(headBlock); err != nil {
+	if err := wrapper.BeaconBlockIsNil(headBlock); err != nil {
 		return err
 	}
 	if headState == nil || headState.IsNil() {
@@ -88,49 +87,19 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 		return nil
 	}

+	// A chain re-org occurred, so we fire an event notifying the rest of the services.
 	s.headLock.RLock()
-	oldHeadBlock, err := s.headBlock()
-	if err != nil {
-		s.headLock.RUnlock()
-		return errors.Wrap(err, "could not get old head block")
-	}
-	oldStateRoot := oldHeadBlock.Block().StateRoot()
+	oldStateRoot := s.headBlock().Block().StateRoot()
 	s.headLock.RUnlock()
 	headSlot := s.HeadSlot()
 	newHeadSlot := headBlock.Block().Slot()
 	newStateRoot := headBlock.Block().StateRoot()
-
-	// A chain re-org occurred, so we fire an event notifying the rest of the services.
-	if headBlock.Block().ParentRoot() != oldHeadRoot {
-		commonRoot, forkSlot, err := s.ForkChoicer().CommonAncestor(ctx, oldHeadRoot, newHeadRoot)
-		if err != nil {
-			log.WithError(err).Error("Could not find common ancestor root")
-			commonRoot = params.BeaconConfig().ZeroHash
-		}
-		dis := headSlot + newHeadSlot - 2*forkSlot
-		dep := math.Max(uint64(headSlot-forkSlot), uint64(newHeadSlot-forkSlot))
-		oldWeight, err := s.ForkChoicer().Weight(oldHeadRoot)
-		if err != nil {
-			log.WithField("root", fmt.Sprintf("%#x", oldHeadRoot)).Warn("could not determine node weight")
-		}
-		newWeight, err := s.ForkChoicer().Weight(newHeadRoot)
-		if err != nil {
-			log.WithField("root", fmt.Sprintf("%#x", newHeadRoot)).Warn("could not determine node weight")
-		}
+	if bytesutil.ToBytes32(headBlock.Block().ParentRoot()) != oldHeadRoot {
 		log.WithFields(logrus.Fields{
-			"newSlot":            fmt.Sprintf("%d", newHeadSlot),
-			"newRoot":            fmt.Sprintf("%#x", newHeadRoot),
-			"newWeight":          newWeight,
-			"oldSlot":            fmt.Sprintf("%d", headSlot),
-			"oldRoot":            fmt.Sprintf("%#x", oldHeadRoot),
-			"oldWeight":          oldWeight,
-			"commonAncestorRoot": fmt.Sprintf("%#x", commonRoot),
-			"distance":           dis,
-			"depth":              dep,
-		}).Info("Chain reorg occurred")
-		reorgDistance.Observe(float64(dis))
-		reorgDepth.Observe(float64(dep))
-
+			"newSlot": fmt.Sprintf("%d", newHeadSlot),
+			"oldSlot": fmt.Sprintf("%d", headSlot),
+		}).Debug("Chain reorg occurred")
+		absoluteSlotDifference := slots.AbsoluteValueSlotDifference(newHeadSlot, headSlot)
 		isOptimistic, err := s.IsOptimistic(ctx)
 		if err != nil {
 			return errors.Wrap(err, "could not check if node is optimistically synced")
@@ -139,26 +108,24 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 			Type: statefeed.Reorg,
 			Data: &ethpbv1.EventChainReorg{
 				Slot:                newHeadSlot,
-				Depth:               math.Max(uint64(headSlot-forkSlot), uint64(newHeadSlot-forkSlot)),
+				Depth:               absoluteSlotDifference,
 				OldHeadBlock:        oldHeadRoot[:],
 				NewHeadBlock:        newHeadRoot[:],
-				OldHeadState:        oldStateRoot[:],
-				NewHeadState:        newStateRoot[:],
+				OldHeadState:        oldStateRoot,
+				NewHeadState:        newStateRoot,
 				Epoch:               slots.ToEpoch(newHeadSlot),
 				ExecutionOptimistic: isOptimistic,
 			},
 		})

-		if err := s.saveOrphanedOperations(ctx, oldHeadRoot, newHeadRoot); err != nil {
+		if err := s.saveOrphanedAtts(ctx, oldHeadRoot, newHeadRoot); err != nil {
 			return err
 		}
 		reorgCount.Inc()
 	}

 	// Cache the new head info.
-	if err := s.setHead(newHeadRoot, headBlock, headState); err != nil {
-		return errors.Wrap(err, "could not set head")
-	}
+	s.setHead(newHeadRoot, headBlock, headState)

 	// Save the new head root to DB.
 	if err := s.cfg.BeaconDB.SaveHeadBlockRoot(ctx, newHeadRoot); err != nil {
@@ -168,7 +135,7 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 	// Forward an event capturing a new chain head over a common event feed
 	// done in a goroutine to avoid blocking the critical runtime main routine.
 	go func() {
-		if err := s.notifyNewHeadEvent(ctx, newHeadSlot, headState, newStateRoot[:], newHeadRoot[:]); err != nil {
+		if err := s.notifyNewHeadEvent(ctx, newHeadSlot, headState, newStateRoot, newHeadRoot[:]); err != nil {
 			log.WithError(err).Error("Could not notify event feed of new chain head")
 		}
 	}()
@@ -180,7 +147,7 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 // root in DB. With the inception of initial-sync-cache-state flag, it uses finalized
 // check point as anchors to resume sync therefore head is no longer needed to be saved on per slot basis.
 func (s *Service) saveHeadNoDB(ctx context.Context, b interfaces.SignedBeaconBlock, r [32]byte, hs state.BeaconState) error {
-	if err := blocks.BeaconBlockIsNil(b); err != nil {
+	if err := wrapper.BeaconBlockIsNil(b); err != nil {
 		return err
 	}
 	cachedHeadRoot, err := s.HeadRoot(ctx)
@@ -191,61 +158,44 @@ func (s *Service) saveHeadNoDB(ctx context.Context, b interfaces.SignedBeaconBlo
 		return nil
 	}

-	bCp, err := b.Copy()
-	if err != nil {
-		return err
-	}
-	if err := s.setHeadInitialSync(r, bCp, hs); err != nil {
-		return errors.Wrap(err, "could not set head")
-	}
+	s.setHeadInitialSync(r, b.Copy(), hs)
 	return nil
 }

 // This sets head view object which is used to track the head slot, root, block and state.
-func (s *Service) setHead(root [32]byte, block interfaces.SignedBeaconBlock, state state.BeaconState) error {
+func (s *Service) setHead(root [32]byte, block interfaces.SignedBeaconBlock, state state.BeaconState) {
 	s.headLock.Lock()
 	defer s.headLock.Unlock()

 	// This does a full copy of the block and state.
-	bCp, err := block.Copy()
-	if err != nil {
-		return err
-	}
 	s.head = &head{
+		slot:  block.Block().Slot(),
 		root:  root,
-		block: bCp,
+		block: block.Copy(),
 		state: state.Copy(),
 	}
-	return nil
 }

 // This sets head view object which is used to track the head slot, root, block and state. The method
 // assumes that state being passed into the method will not be modified by any other alternate
 // caller which holds the state's reference.
-func (s *Service) setHeadInitialSync(root [32]byte, block interfaces.SignedBeaconBlock, state state.BeaconState) error {
+func (s *Service) setHeadInitialSync(root [32]byte, block interfaces.SignedBeaconBlock, state state.BeaconState) {
 	s.headLock.Lock()
 	defer s.headLock.Unlock()

 	// This does a full copy of the block only.
-	bCp, err := block.Copy()
-	if err != nil {
-		return err
-	}
 	s.head = &head{
+		slot:  block.Block().Slot(),
 		root:  root,
-		block: bCp,
+		block: block.Copy(),
 		state: state,
 	}
-	return nil
 }

 // This returns the head slot.
 // This is a lock free version.
 func (s *Service) headSlot() types.Slot {
-	if s.head == nil || s.head.block == nil || s.head.block.Block() == nil {
-		return 0
-	}
-	return s.head.block.Block().Slot()
+	return s.head.slot
 }

 // This returns the head root.
@@ -262,7 +212,7 @@ func (s *Service) headRoot() [32]byte {
 // This returns the head block.
 // It does a full copy on head block for immutability.
 // This is a lock free version.
-func (s *Service) headBlock() (interfaces.SignedBeaconBlock, error) {
+func (s *Service) headBlock() interfaces.SignedBeaconBlock {
 	return s.head.block.Copy()
 }

@@ -358,10 +308,10 @@ func (s *Service) notifyNewHeadEvent(
 	return nil
 }

-// This saves the Attestations and BLSToExecChanges between `orphanedRoot` and the common ancestor root that is derived using `newHeadRoot`.
+// This saves the attestations between `orphanedRoot` and the common ancestor root that is derived using `newHeadRoot`.
 // It also filters out the attestations that is one epoch older as a defense so invalid attestations don't flow into the attestation pool.
-func (s *Service) saveOrphanedOperations(ctx context.Context, orphanedRoot [32]byte, newHeadRoot [32]byte) error {
-	commonAncestorRoot, _, err := s.ForkChoicer().CommonAncestor(ctx, newHeadRoot, orphanedRoot)
+func (s *Service) saveOrphanedAtts(ctx context.Context, orphanedRoot [32]byte, newHeadRoot [32]byte) error {
+	commonAncestorRoot, err := s.ForkChoicer().CommonAncestorRoot(ctx, newHeadRoot, orphanedRoot)
 	switch {
 	// Exit early if there's no common ancestor and root doesn't exist, there would be nothing to save.
 	case errors.Is(err, forkchoice.ErrUnknownCommonAncestor):
@@ -399,17 +349,7 @@ func (s *Service) saveOrphanedOperations(ctx context.Context, orphanedRoot [32]b
 			}
 			saveOrphanedAttCount.Inc()
 		}
-		if orphanedBlk.Version() >= version.Capella {
-			changes, err := orphanedBlk.Block().Body().BLSToExecutionChanges()
-			if err != nil {
-				return errors.Wrap(err, "could not get BLSToExecutionChanges")
-			}
-			for _, c := range changes {
-				s.cfg.BLSToExecPool.InsertBLSToExecChange(c)
-			}
-		}
-		parentRoot := orphanedBlk.Block().ParentRoot()
-		orphanedRoot = bytesutil.ToBytes32(parentRoot[:])
+		orphanedRoot = bytesutil.ToBytes32(orphanedBlk.Block().ParentRoot())
 	}
 	return nil
 }
--- a/beacon-chain/blockchain/head_sync_committee_info.go
+++ b/beacon-chain/blockchain/head_sync_committee_info.go
@@ -5,17 +5,17 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/async"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/altair"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/signing"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/async"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

 // Initialize the state cache for sync committees.
--- a/beacon-chain/blockchain/head_sync_committee_info_test.go
+++ b/beacon-chain/blockchain/head_sync_committee_info_test.go
@@ -4,23 +4,22 @@ import (
 	"context"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/signing"
-	dbtest "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	dbtest "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

 func TestService_headSyncCommitteeFetcher_Errors(t *testing.T) {
 	beaconDB := dbtest.SetupDB(t)
 	c := &Service{
 		cfg: &config{
-			StateGen: stategen.New(beaconDB, doublylinkedtree.New()),
+			StateGen: stategen.New(beaconDB),
 		},
 	}
 	c.head = &head{}
@@ -38,7 +37,7 @@ func TestService_HeadDomainFetcher_Errors(t *testing.T) {
 	beaconDB := dbtest.SetupDB(t)
 	c := &Service{
 		cfg: &config{
-			StateGen: stategen.New(beaconDB, doublylinkedtree.New()),
+			StateGen: stategen.New(beaconDB),
 		},
 	}
 	c.head = &head{}
--- a/beacon-chain/blockchain/head_test.go
+++ b/beacon-chain/blockchain/head_test.go
@@ -7,22 +7,21 @@ import (
 	"testing"
 	"time"

-	mock "github.com/prysmaticlabs/prysm/v3/beacon-chain/blockchain/testing"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/blstoexec"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/config/features"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpbv1 "github.com/prysmaticlabs/prysm/v3/proto/eth/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	mock "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/config/features"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpbv1 "github.com/prysmaticlabs/prysm/proto/eth/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -31,8 +30,8 @@ func TestSaveHead_Same(t *testing.T) {
 	service := setupBeaconChain(t, beaconDB)

 	r := [32]byte{'A'}
-	service.head = &head{root: r}
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	service.head = &head{slot: 0, root: r}
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	st, _ := util.DeterministicGenesisState(t, 1)
 	require.NoError(t, service.saveHead(context.Background(), r, b, st))
@@ -50,10 +49,11 @@ func TestSaveHead_Different(t *testing.T) {
 	require.NoError(t, err)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	state, blkRoot, err := prepareForkchoiceState(ctx, oldBlock.Block().Slot(), oldRoot, oldBlock.Block().ParentRoot(), [32]byte{}, ojc, ofc)
+	state, blkRoot, err := prepareForkchoiceState(ctx, oldBlock.Block().Slot(), oldRoot, bytesutil.ToBytes32(oldBlock.Block().ParentRoot()), [32]byte{}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 	service.head = &head{
+		slot:  0,
 		root:  oldRoot,
 		block: oldBlock,
 	}
@@ -65,11 +65,7 @@ func TestSaveHead_Different(t *testing.T) {
 	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
-	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot()-1, wsb.Block().ParentRoot(), service.cfg.ForkChoiceStore.CachedHeadRoot(), [32]byte{}, ojc, ofc)
-	require.NoError(t, err)
-	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
-
-	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot(), newRoot, wsb.Block().ParentRoot(), [32]byte{}, ojc, ofc)
+	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot(), newRoot, bytesutil.ToBytes32(wsb.Block().ParentRoot()), [32]byte{}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 	headState, err := util.NewBeaconState()
@@ -84,12 +80,8 @@ func TestSaveHead_Different(t *testing.T) {
 	cachedRoot, err := service.HeadRoot(context.Background())
 	require.NoError(t, err)
 	assert.DeepEqual(t, cachedRoot, newRoot[:], "Head did not change")
-	headBlock, err := service.headBlock()
-	require.NoError(t, err)
-	pb, err := headBlock.Proto()
-	require.NoError(t, err)
-	assert.DeepEqual(t, newHeadSignedBlock, pb, "Head did not change")
-	assert.DeepSSZEqual(t, headState.ToProto(), service.headState(ctx).ToProto(), "Head did not change")
+	assert.DeepEqual(t, newHeadSignedBlock, service.headBlock().Proto(), "Head did not change")
+	assert.DeepSSZEqual(t, headState.CloneInnerState(), service.headState(ctx).CloneInnerState(), "Head did not change")
 }

 func TestSaveHead_Different_Reorg(t *testing.T) {
@@ -103,19 +95,16 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	require.NoError(t, err)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
-	state, blkRoot, err := prepareForkchoiceState(ctx, oldBlock.Block().Slot(), oldRoot, oldBlock.Block().ParentRoot(), [32]byte{}, ojc, ofc)
+	state, blkRoot, err := prepareForkchoiceState(ctx, oldBlock.Block().Slot(), oldRoot, bytesutil.ToBytes32(oldBlock.Block().ParentRoot()), [32]byte{}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 	service.head = &head{
+		slot:  0,
 		root:  oldRoot,
 		block: oldBlock,
 	}

 	reorgChainParent := [32]byte{'B'}
-	state, blkRoot, err = prepareForkchoiceState(ctx, 0, reorgChainParent, oldRoot, oldBlock.Block().ParentRoot(), ojc, ofc)
-	require.NoError(t, err)
-	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
-
 	newHeadSignedBlock := util.NewBeaconBlock()
 	newHeadSignedBlock.Block.Slot = 1
 	newHeadSignedBlock.Block.ParentRoot = reorgChainParent[:]
@@ -124,7 +113,7 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	wsb := util.SaveBlock(t, context.Background(), service.cfg.BeaconDB, newHeadSignedBlock)
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
-	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot(), newRoot, wsb.Block().ParentRoot(), [32]byte{}, ojc, ofc)
+	state, blkRoot, err = prepareForkchoiceState(ctx, wsb.Block().Slot(), newRoot, bytesutil.ToBytes32(wsb.Block().ParentRoot()), [32]byte{}, ojc, ofc)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 	headState, err := util.NewBeaconState()
@@ -141,15 +130,9 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	if !bytes.Equal(cachedRoot, newRoot[:]) {
 		t.Error("Head did not change")
 	}
-	headBlock, err := service.headBlock()
-	require.NoError(t, err)
-	pb, err := headBlock.Proto()
-	require.NoError(t, err)
-	assert.DeepEqual(t, newHeadSignedBlock, pb, "Head did not change")
-	assert.DeepSSZEqual(t, headState.ToProto(), service.headState(ctx).ToProto(), "Head did not change")
+	assert.DeepEqual(t, newHeadSignedBlock, service.headBlock().Proto(), "Head did not change")
+	assert.DeepSSZEqual(t, headState.CloneInnerState(), service.headState(ctx).CloneInnerState(), "Head did not change")
 	require.LogsContain(t, hook, "Chain reorg occurred")
-	require.LogsContain(t, hook, "distance=1")
-	require.LogsContain(t, hook, "depth=1")
 }

 func TestCacheJustifiedStateBalances_CanCache(t *testing.T) {
@@ -232,6 +215,60 @@ func Test_notifyNewHeadEvent(t *testing.T) {
 	})
 }

+func TestSaveOrphanedAtts_NoCommonAncestor(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//    -4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	util.SaveBlock(t, ctx, service.cfg.BeaconDB, blkG)
+	rG, err := blkG.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+		ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+		state, blkRoot, err := prepareForkchoiceState(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, ojc, ofc)
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertNode(ctx, state, blkRoot))
+		util.SaveBlock(t, ctx, beaconDB, blk)
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
+	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
+}
+
 func TestSaveOrphanedAtts(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
@@ -284,7 +321,7 @@ func TestSaveOrphanedAtts(t *testing.T) {
 		util.SaveBlock(t, ctx, beaconDB, blk)
 	}

-	require.NoError(t, service.saveOrphanedOperations(ctx, r3, r4))
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
 	require.Equal(t, 3, service.cfg.AttPool.AggregatedAttestationCount())
 	wantAtts := []*ethpb.Attestation{
 		blk3.Block.Body.Attestations[0],
@@ -302,37 +339,31 @@ func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.cfg.BLSToExecPool = blstoexec.NewPool()
 	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+2)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)

 	// Chain setup
 	// 0 -- 1 -- 2
 	//  \-4
-	st, keys := util.DeterministicGenesisStateCapella(t, 64)
-	blkConfig := util.DefaultBlockGenConfig()
-	blkConfig.NumBLSChanges = 5
-	blkG, err := util.GenerateFullBlockCapella(st, keys, blkConfig, 1)
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
 	assert.NoError(t, err)
 	util.SaveBlock(t, ctx, service.cfg.BeaconDB, blkG)
 	rG, err := blkG.Block.HashTreeRoot()
 	require.NoError(t, err)

-	blkConfig.NumBLSChanges = 10
-	blk1, err := util.GenerateFullBlockCapella(st, keys, blkConfig, 2)
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
 	assert.NoError(t, err)
 	blk1.Block.ParentRoot = rG[:]
 	r1, err := blk1.Block.HashTreeRoot()
 	require.NoError(t, err)

-	blkConfig.NumBLSChanges = 15
-	blk2, err := util.GenerateFullBlockCapella(st, keys, blkConfig, 3)
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
 	assert.NoError(t, err)
 	blk2.Block.ParentRoot = r1[:]
 	r2, err := blk2.Block.HashTreeRoot()
 	require.NoError(t, err)

-	blk4 := util.NewBeaconBlockCapella()
-	blkConfig.NumBLSChanges = 0
+	blk4 := util.NewBeaconBlock()
 	blk4.Block.Slot = 4
 	blk4.Block.ParentRoot = rG[:]
 	r4, err := blk4.Block.HashTreeRoot()
@@ -340,7 +371,7 @@ func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
 	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}

-	for _, blk := range []*ethpb.SignedBeaconBlockCapella{blkG, blk1, blk2, blk4} {
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk4} {
 		r, err := blk.Block.HashTreeRoot()
 		require.NoError(t, err)
 		state, blkRoot, err := prepareForkchoiceState(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, ojc, ofc)
@@ -349,16 +380,72 @@ func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
 		util.SaveBlock(t, ctx, beaconDB, blk)
 	}

-	require.NoError(t, service.saveOrphanedOperations(ctx, r2, r4))
-	require.Equal(t, 1, service.cfg.AttPool.AggregatedAttestationCount())
-	pending, err := service.cfg.BLSToExecPool.PendingBLSToExecChanges()
+	require.NoError(t, service.saveOrphanedAtts(ctx, r2, r4))
+	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
+}
+
+func TestSaveOrphanedAtts_NoCommonAncestor_DoublyLinkedTrie(t *testing.T) {
+	resetCfg := features.InitWithReset(&features.Flags{
+		EnableForkChoiceDoublyLinkedTree: true,
+	})
+	defer resetCfg()
+
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//    -4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	util.SaveBlock(t, ctx, service.cfg.BeaconDB, blkG)
+	rG, err := blkG.Block.HashTreeRoot()
 	require.NoError(t, err)
-	require.Equal(t, 15, len(pending))
+
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		state, blkRoot, err := prepareForkchoiceState(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, ojc, ofc)
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertNode(ctx, state, blkRoot))
+		util.SaveBlock(t, ctx, beaconDB, blk)
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
+	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
 }

 func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {
 	resetCfg := features.InitWithReset(&features.Flags{
-		DisableForkchoiceDoublyLinkedTree: false,
+		EnableForkChoiceDoublyLinkedTree: true,
 	})
 	defer resetCfg()

@@ -412,7 +499,7 @@ func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {
 		util.SaveBlock(t, ctx, beaconDB, blk)
 	}

-	require.NoError(t, service.saveOrphanedOperations(ctx, r3, r4))
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
 	require.Equal(t, 3, service.cfg.AttPool.AggregatedAttestationCount())
 	wantAtts := []*ethpb.Attestation{
 		blk3.Block.Body.Attestations[0],
@@ -428,7 +515,7 @@ func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {

 func TestSaveOrphanedAtts_CanFilter_DoublyLinkedTrie(t *testing.T) {
 	resetCfg := features.InitWithReset(&features.Flags{
-		DisableForkchoiceDoublyLinkedTree: false,
+		EnableForkChoiceDoublyLinkedTree: true,
 	})
 	defer resetCfg()

@@ -476,7 +563,7 @@ func TestSaveOrphanedAtts_CanFilter_DoublyLinkedTrie(t *testing.T) {
 		util.SaveBlock(t, ctx, beaconDB, blk)
 	}

-	require.NoError(t, service.saveOrphanedOperations(ctx, r2, r4))
+	require.NoError(t, service.saveOrphanedAtts(ctx, r2, r4))
 	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
 }

@@ -487,7 +574,7 @@ func TestUpdateHead_noSavedChanges(t *testing.T) {
 	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}

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

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
 )

 // This saves a beacon block to the initial sync blocks cache. It rate limits how many blocks
@@ -56,7 +56,7 @@ func (s *Service) getBlock(ctx context.Context, r [32]byte) (interfaces.SignedBe
 			return nil, errors.Wrap(err, "could not retrieve block from db")
 		}
 	}
-	if err := blocks.BeaconBlockIsNil(b); err != nil {
+	if err := wrapper.BeaconBlockIsNil(b); err != nil {
 		return nil, errBlockNotFoundInCacheOrDB
 	}
 	return b, nil
--- a/beacon-chain/blockchain/init_sync_process_block_test.go
+++ b/beacon-chain/blockchain/init_sync_process_block_test.go
@@ -4,10 +4,10 @@ import (
 	"context"
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 )

 func TestService_getBlock(t *testing.T) {
@@ -27,9 +27,9 @@ func TestService_getBlock(t *testing.T) {
 	require.ErrorIs(t, err, errBlockNotFoundInCacheOrDB)

 	// block in cache
-	b, err := blocks.NewSignedBeaconBlock(b1)
+	b, err := wrapper.WrappedSignedBeaconBlock(b1)
 	require.NoError(t, err)
-	require.NoError(t, s.saveInitSyncBlock(ctx, r1, b))
+	s.saveInitSyncBlock(ctx, r1, b)
 	got, err := s.getBlock(ctx, r1)
 	require.NoError(t, err)
 	require.DeepEqual(t, b, got)
@@ -57,9 +57,9 @@ func TestService_hasBlockInInitSyncOrDB(t *testing.T) {
 	require.Equal(t, false, s.hasBlockInInitSyncOrDB(ctx, [32]byte{}))

 	// block in cache
-	b, err := blocks.NewSignedBeaconBlock(b1)
+	b, err := wrapper.WrappedSignedBeaconBlock(b1)
 	require.NoError(t, err)
-	require.NoError(t, s.saveInitSyncBlock(ctx, r1, b))
+	s.saveInitSyncBlock(ctx, r1, b)
 	require.Equal(t, true, s.hasBlockInInitSyncOrDB(ctx, r1))

 	// block in db
--- a/beacon-chain/blockchain/init_test.go
+++ b/beacon-chain/blockchain/init_test.go
@@ -1,7 +1,7 @@
 package blockchain

 import (
-	"github.com/prysmaticlabs/prysm/v3/config/params"
+	"github.com/prysmaticlabs/prysm/config/params"
 )

 func init() {
--- a/beacon-chain/blockchain/log.go
+++ b/beacon-chain/blockchain/log.go
@@ -6,15 +6,14 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	consensusBlocks "github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
-	prysmTime "github.com/prysmaticlabs/prysm/v3/time"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/runtime/version"
+	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"github.com/sirupsen/logrus"
 )

@@ -38,29 +37,24 @@ func logStateTransitionData(b interfaces.BeaconBlock) error {
 	if len(b.Body().VoluntaryExits()) > 0 {
 		log = log.WithField("voluntaryExits", len(b.Body().VoluntaryExits()))
 	}
-	if b.Version() >= version.Altair {
+	if b.Version() == version.Altair || b.Version() == version.Bellatrix {
 		agg, err := b.Body().SyncAggregate()
 		if err != nil {
 			return err
 		}
 		log = log.WithField("syncBitsCount", agg.SyncCommitteeBits.Count())
 	}
-	if b.Version() >= version.Bellatrix {
+	if b.Version() == version.Bellatrix {
 		p, err := b.Body().Execution()
 		if err != nil {
 			return err
 		}
 		log = log.WithField("payloadHash", fmt.Sprintf("%#x", bytesutil.Trunc(p.BlockHash())))
 		txs, err := p.Transactions()
-		switch {
-		case errors.Is(err, consensusBlocks.ErrUnsupportedGetter):
-		case err != nil:
+		if err != nil {
 			return err
-		default:
-			log = log.WithField("txCount", len(txs))
-			txsPerSlotCount.Set(float64(len(txs)))
 		}
-
+		log = log.WithField("txCount", len(txs))
 	}
 	log.Info("Finished applying state transition")
 	return nil
@@ -73,7 +67,6 @@ func logBlockSyncStatus(block interfaces.BeaconBlock, blockRoot [32]byte, justif
 	}
 	level := log.Logger.GetLevel()
 	if level >= logrus.DebugLevel {
-		parentRoot := block.ParentRoot()
 		log.WithFields(logrus.Fields{
 			"slot":                      block.Slot(),
 			"slotInEpoch":               block.Slot() % params.BeaconConfig().SlotsPerEpoch,
@@ -83,11 +76,10 @@ func logBlockSyncStatus(block interfaces.BeaconBlock, blockRoot [32]byte, justif
 			"justifiedRoot":             fmt.Sprintf("0x%s...", hex.EncodeToString(justified.Root)[:8]),
 			"finalizedEpoch":            finalized.Epoch,
 			"finalizedRoot":             fmt.Sprintf("0x%s...", hex.EncodeToString(finalized.Root)[:8]),
-			"parentRoot":                fmt.Sprintf("0x%s...", hex.EncodeToString(parentRoot[:])[:8]),
+			"parentRoot":                fmt.Sprintf("0x%s...", hex.EncodeToString(block.ParentRoot())[:8]),
 			"version":                   version.String(block.Version()),
 			"sinceSlotStartTime":        prysmTime.Now().Sub(startTime),
 			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime),
-			"deposits":                  len(block.Body().Deposits()),
 		}).Debug("Synced new block")
 	} else {
 		log.WithFields(logrus.Fields{
@@ -118,24 +110,12 @@ func logPayload(block interfaces.BeaconBlock) error {
 		return errors.New("gas limit should not be 0")
 	}
 	gasUtilized := float64(payload.GasUsed()) / float64(payload.GasLimit())
-	fields := logrus.Fields{
+
+	log.WithFields(logrus.Fields{
 		"blockHash":   fmt.Sprintf("%#x", bytesutil.Trunc(payload.BlockHash())),
 		"parentHash":  fmt.Sprintf("%#x", bytesutil.Trunc(payload.ParentHash())),
 		"blockNumber": payload.BlockNumber,
 		"gasUtilized": fmt.Sprintf("%.2f", gasUtilized),
-	}
-	if block.Version() >= version.Capella {
-		withdrawals, err := payload.Withdrawals()
-		if err != nil {
-			return errors.Wrap(err, "could not get withdrawals")
-		}
-		fields["withdrawals"] = len(withdrawals)
-		changes, err := block.Body().BLSToExecutionChanges()
-		if err != nil {
-			return errors.Wrap(err, "could not get BLSToExecutionChanges")
-		}
-		fields["blsToExecutionChanges"] = len(changes)
-	}
-	log.WithFields(fields).Debug("Synced new payload")
+	}).Debug("Synced new payload")
 	return nil
 }
--- a/beacon-chain/blockchain/log_test.go
+++ b/beacon-chain/blockchain/log_test.go
@@ -3,11 +3,11 @@ package blockchain
 import (
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	enginev1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -21,7 +21,7 @@ func Test_logStateTransitionData(t *testing.T) {
 			},
 		},
 	}
-	wrappedPayloadBlk, err := blocks.NewBeaconBlock(payloadBlk)
+	wrappedPayloadBlk, err := wrapper.WrappedBeaconBlock(payloadBlk)
 	require.NoError(t, err)
 	tests := []struct {
 		name string
@@ -30,7 +30,7 @@ func Test_logStateTransitionData(t *testing.T) {
 	}{
 		{name: "empty block body",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}})
+				wb, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}})
 				require.NoError(t, err)
 				return wb
 			},
@@ -38,7 +38,7 @@ func Test_logStateTransitionData(t *testing.T) {
 		},
 		{name: "has attestation",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{Attestations: []*ethpb.Attestation{{}}}})
+				wb, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{Attestations: []*ethpb.Attestation{{}}}})
 				require.NoError(t, err)
 				return wb
 			},
@@ -46,7 +46,7 @@ func Test_logStateTransitionData(t *testing.T) {
 		},
 		{name: "has deposit",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(
+				wb, err := wrapper.WrappedBeaconBlock(
 					&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
 						Attestations: []*ethpb.Attestation{{}},
 						Deposits:     []*ethpb.Deposit{{}}}})
@@ -57,7 +57,7 @@ func Test_logStateTransitionData(t *testing.T) {
 		},
 		{name: "has attester slashing",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
+				wb, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
 					AttesterSlashings: []*ethpb.AttesterSlashing{{}}}})
 				require.NoError(t, err)
 				return wb
@@ -66,7 +66,7 @@ func Test_logStateTransitionData(t *testing.T) {
 		},
 		{name: "has proposer slashing",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
+				wb, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
 					ProposerSlashings: []*ethpb.ProposerSlashing{{}}}})
 				require.NoError(t, err)
 				return wb
@@ -75,7 +75,7 @@ func Test_logStateTransitionData(t *testing.T) {
 		},
 		{name: "has exit",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
+				wb, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
 					VoluntaryExits: []*ethpb.SignedVoluntaryExit{{}}}})
 				require.NoError(t, err)
 				return wb
@@ -84,7 +84,7 @@ func Test_logStateTransitionData(t *testing.T) {
 		},
 		{name: "has everything",
 			b: func() interfaces.BeaconBlock {
-				wb, err := blocks.NewBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
+				wb, err := wrapper.WrappedBeaconBlock(&ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{
 					Attestations:      []*ethpb.Attestation{{}},
 					Deposits:          []*ethpb.Deposit{{}},
 					AttesterSlashings: []*ethpb.AttesterSlashing{{}},
--- a/beacon-chain/blockchain/metrics.go
+++ b/beacon-chain/blockchain/metrics.go
@@ -6,15 +6,15 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/altair"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/epoch/precompute"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/runtime/version"
 )

 var (
@@ -158,61 +158,10 @@ var (
 		Name: "forkchoice_updated_optimistic_node_count",
 		Help: "Count the number of optimistic nodes after forkchoiceUpdated EE call",
 	})
-	forkchoiceUpdatedInvalidNodeCount = promauto.NewCounter(prometheus.CounterOpts{
-		Name: "forkchoice_updated_invalid_node_count",
-		Help: "Count the number of invalid nodes after forkchoiceUpdated EE call",
-	})
-	txsPerSlotCount = promauto.NewGauge(prometheus.GaugeOpts{
-		Name: "txs_per_slot_count",
-		Help: "Count the number of txs per slot",
-	})
 	missedPayloadIDFilledCount = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "missed_payload_id_filled_count",
 		Help: "",
 	})
-	onBlockProcessingTime = promauto.NewSummary(prometheus.SummaryOpts{
-		Name: "on_block_processing_milliseconds",
-		Help: "Total time in milliseconds to complete a call to onBlock()",
-	})
-	stateTransitionProcessingTime = promauto.NewSummary(prometheus.SummaryOpts{
-		Name: "state_transition_processing_milliseconds",
-		Help: "Total time to call a state transition in onBlock()",
-	})
-	processAttsElapsedTime = promauto.NewHistogram(
-		prometheus.HistogramOpts{
-			Name:    "process_attestations_milliseconds",
-			Help:    "Captures latency for process attestations (forkchoice) in milliseconds",
-			Buckets: []float64{1, 5, 20, 100, 500, 1000},
-		},
-	)
-	newAttHeadElapsedTime = promauto.NewHistogram(
-		prometheus.HistogramOpts{
-			Name:    "new_att_head_milliseconds",
-			Help:    "Captures latency for new attestation head in milliseconds",
-			Buckets: []float64{1, 5, 20, 100, 500, 1000},
-		},
-	)
-	newBlockHeadElapsedTime = promauto.NewHistogram(
-		prometheus.HistogramOpts{
-			Name:    "new_block_head_milliseconds",
-			Help:    "Captures latency for new block head in milliseconds",
-			Buckets: []float64{1, 5, 20, 100, 500, 1000},
-		},
-	)
-	reorgDistance = promauto.NewHistogram(
-		prometheus.HistogramOpts{
-			Name:    "reorg_distance",
-			Help:    "Captures distance of reorgs. Distance is defined as the number of blocks between the old head and the new head",
-			Buckets: []float64{1, 2, 4, 8, 16, 32, 64},
-		},
-	)
-	reorgDepth = promauto.NewHistogram(
-		prometheus.HistogramOpts{
-			Name:    "reorg_depth",
-			Help:    "Captures depth of reorgs. Depth is defined as the number of blocks between the head and the common ancestor",
-			Buckets: []float64{1, 2, 4, 8, 16, 32},
-		},
-	)
 )

 // reportSlotMetrics reports slot related metrics.
@@ -249,7 +198,7 @@ func reportEpochMetrics(ctx context.Context, postState, headState state.BeaconSt
 	for i, validator := range postState.Validators() {
 		bal, err := postState.BalanceAtIndex(types.ValidatorIndex(i))
 		if err != nil {
-			log.WithError(err).Error("Could not load validator balance")
+			log.Errorf("Could not load validator balance: %v", err)
 			continue
 		}
 		if validator.Slashed {
@@ -317,8 +266,9 @@ func reportEpochMetrics(ctx context.Context, postState, headState state.BeaconSt
 	var b *precompute.Balance
 	var v []*precompute.Validator
 	var err error
-
-	if headState.Version() == version.Phase0 {
+	switch headState.Version() {
+	case version.Phase0:
+		// Validator participation should be viewed on the canonical chain.
 		v, b, err = precompute.New(ctx, headState)
 		if err != nil {
 			return err
@@ -327,7 +277,7 @@ func reportEpochMetrics(ctx context.Context, postState, headState state.BeaconSt
 		if err != nil {
 			return err
 		}
-	} else if headState.Version() >= version.Altair {
+	case version.Altair, version.Bellatrix:
 		v, b, err = altair.InitializePrecomputeValidators(ctx, headState)
 		if err != nil {
 			return err
@@ -336,10 +286,9 @@ func reportEpochMetrics(ctx context.Context, postState, headState state.BeaconSt
 		if err != nil {
 			return err
 		}
-	} else {
-		return errors.Errorf("invalid state type provided: %T", headState.ToProtoUnsafe())
+	default:
+		return errors.Errorf("invalid state type provided: %T", headState.InnerStateUnsafe())
 	}
-
 	prevEpochActiveBalances.Set(float64(b.ActivePrevEpoch))
 	prevEpochSourceBalances.Set(float64(b.PrevEpochAttested))
 	prevEpochTargetBalances.Set(float64(b.PrevEpochTargetAttested))
--- a/beacon-chain/blockchain/metrics_test.go
+++ b/beacon-chain/blockchain/metrics_test.go
@@ -4,9 +4,9 @@ import (
 	"context"
 	"testing"

-	eth "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 )

 func TestReportEpochMetrics_BadHeadState(t *testing.T) {
--- a/beacon-chain/blockchain/mock_test.go
+++ b/beacon-chain/blockchain/mock_test.go
@@ -5,18 +5,18 @@ import (
 	"errors"
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
 )

 func testServiceOptsWithDB(t *testing.T) []Option {
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	return []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 }
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -1,21 +1,20 @@
 package blockchain

 import (
-	"github.com/prysmaticlabs/prysm/v3/async/event"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache/depositcache"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/execution"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/attestations"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/blstoexec"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/slashings"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/voluntaryexits"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/p2p"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/async/event"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/slashings"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/voluntaryexits"
+	"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 )

 type Option func(s *Service) error
@@ -45,7 +44,7 @@ func WithDatabase(beaconDB db.HeadAccessDatabase) Option {
 }

 // WithChainStartFetcher to retrieve information about genesis.
-func WithChainStartFetcher(f execution.ChainStartFetcher) Option {
+func WithChainStartFetcher(f powchain.ChainStartFetcher) Option {
 	return func(s *Service) error {
 		s.cfg.ChainStartFetcher = f
 		return nil
@@ -53,7 +52,7 @@ func WithChainStartFetcher(f execution.ChainStartFetcher) Option {
 }

 // WithExecutionEngineCaller to call execution engine.
-func WithExecutionEngineCaller(c execution.EngineCaller) Option {
+func WithExecutionEngineCaller(c powchain.EngineCaller) Option {
 	return func(s *Service) error {
 		s.cfg.ExecutionEngineCaller = c
 		return nil
@@ -100,14 +99,6 @@ func WithSlashingPool(p slashings.PoolManager) Option {
 	}
 }

-// WithBLSToExecPool to keep track of BLS to Execution address changes.
-func WithBLSToExecPool(p blstoexec.PoolManager) Option {
-	return func(s *Service) error {
-		s.cfg.BLSToExecPool = p
-		return nil
-	}
-}
-
 // WithP2PBroadcaster to broadcast messages after appropriate processing.
 func WithP2PBroadcaster(p p2p.Broadcaster) Option {
 	return func(s *Service) error {
--- a/beacon-chain/blockchain/pow_block.go
+++ b/beacon-chain/blockchain/pow_block.go
@@ -10,36 +10,34 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/holiman/uint256"
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"github.com/sirupsen/logrus"
 )

 // validateMergeBlock validates terminal block hash in the event of manual overrides before checking for total difficulty.
 //
 // def validate_merge_block(block: BeaconBlock) -> None:
+//    if TERMINAL_BLOCK_HASH != Hash32():
+//        # If `TERMINAL_BLOCK_HASH` is used as an override, the activation epoch must be reached.
+//        assert compute_epoch_at_slot(block.slot) >= TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH
+//        assert block.body.execution_payload.parent_hash == TERMINAL_BLOCK_HASH
+//        return
 //
-//	if TERMINAL_BLOCK_HASH != Hash32():
-//	    # If `TERMINAL_BLOCK_HASH` is used as an override, the activation epoch must be reached.
-//	    assert compute_epoch_at_slot(block.slot) >= TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH
-//	    assert block.body.execution_payload.parent_hash == TERMINAL_BLOCK_HASH
-//	    return
-//
-//	pow_block = get_pow_block(block.body.execution_payload.parent_hash)
-//	# Check if `pow_block` is available
-//	assert pow_block is not None
-//	pow_parent = get_pow_block(pow_block.parent_hash)
-//	# Check if `pow_parent` is available
-//	assert pow_parent is not None
-//	# Check if `pow_block` is a valid terminal PoW block
-//	assert is_valid_terminal_pow_block(pow_block, pow_parent)
+//    pow_block = get_pow_block(block.body.execution_payload.parent_hash)
+//    # Check if `pow_block` is available
+//    assert pow_block is not None
+//    pow_parent = get_pow_block(pow_block.parent_hash)
+//    # Check if `pow_parent` is available
+//    assert pow_parent is not None
+//    # Check if `pow_block` is a valid terminal PoW block
+//    assert is_valid_terminal_pow_block(pow_block, pow_parent)
 func (s *Service) validateMergeBlock(ctx context.Context, b interfaces.SignedBeaconBlock) error {
-	if err := blocks.BeaconBlockIsNil(b); err != nil {
+	if err := wrapper.BeaconBlockIsNil(b); err != nil {
 		return err
 	}
 	payload, err := b.Block().Body().Execution()
@@ -93,7 +91,6 @@ func (s *Service) getBlkParentHashAndTD(ctx context.Context, blkHash []byte) ([]
 	if blk == nil {
 		return nil, nil, errors.New("pow block is nil")
 	}
-	blk.Version = version.Bellatrix
 	blkTDBig, err := hexutil.DecodeBig(blk.TotalDifficulty)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "could not decode merge block total difficulty")
@@ -108,11 +105,10 @@ func (s *Service) getBlkParentHashAndTD(ctx context.Context, blkHash []byte) ([]
 // validateTerminalBlockHash validates if the merge block is a valid terminal PoW block.
 // spec code:
 // if TERMINAL_BLOCK_HASH != Hash32():
-//
-//	# If `TERMINAL_BLOCK_HASH` is used as an override, the activation epoch must be reached.
-//	assert compute_epoch_at_slot(block.slot) >= TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH
-//	assert block.body.execution_payload.parent_hash == TERMINAL_BLOCK_HASH
-//	return
+//        # If `TERMINAL_BLOCK_HASH` is used as an override, the activation epoch must be reached.
+//        assert compute_epoch_at_slot(block.slot) >= TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH
+//        assert block.body.execution_payload.parent_hash == TERMINAL_BLOCK_HASH
+//        return
 func validateTerminalBlockHash(blkSlot types.Slot, payload interfaces.ExecutionData) error {
 	if bytesutil.ToBytes32(params.BeaconConfig().TerminalBlockHash.Bytes()) == [32]byte{} {
 		return nil
@@ -129,10 +125,9 @@ func validateTerminalBlockHash(blkSlot types.Slot, payload interfaces.ExecutionD
 // validateTerminalBlockDifficulties validates terminal pow block by comparing own total difficulty with parent's total difficulty.
 //
 // def is_valid_terminal_pow_block(block: PowBlock, parent: PowBlock) -> bool:
-//
-//	is_total_difficulty_reached = block.total_difficulty >= TERMINAL_TOTAL_DIFFICULTY
-//	is_parent_total_difficulty_valid = parent.total_difficulty < TERMINAL_TOTAL_DIFFICULTY
-//	return is_total_difficulty_reached and is_parent_total_difficulty_valid
+//    is_total_difficulty_reached = block.total_difficulty >= TERMINAL_TOTAL_DIFFICULTY
+//    is_parent_total_difficulty_valid = parent.total_difficulty < TERMINAL_TOTAL_DIFFICULTY
+//    return is_total_difficulty_reached and is_parent_total_difficulty_valid
 func validateTerminalBlockDifficulties(currentDifficulty *uint256.Int, parentDifficulty *uint256.Int) (bool, error) {
 	b, ok := new(big.Int).SetString(params.BeaconConfig().TerminalTotalDifficulty, 10)
 	if !ok {
--- a/beacon-chain/blockchain/pow_block_test.go
+++ b/beacon-chain/blockchain/pow_block_test.go
@@ -8,16 +8,16 @@ import (

 	gethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/holiman/uint256"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	mocks "github.com/prysmaticlabs/prysm/v3/beacon-chain/execution/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	enginev1 "github.com/prysmaticlabs/prysm/v3/proto/engine/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	mocks "github.com/prysmaticlabs/prysm/beacon-chain/powchain/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
 )

 func Test_validTerminalPowBlock(t *testing.T) {
@@ -109,10 +109,10 @@ func Test_validateMergeBlock(t *testing.T) {

 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 	service, err := NewService(ctx, opts...)
@@ -145,7 +145,7 @@ func Test_validateMergeBlock(t *testing.T) {
 			},
 		},
 	}
-	bk, err := blocks.NewSignedBeaconBlock(blk)
+	bk, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 	require.NoError(t, service.validateMergeBlock(ctx, bk))

@@ -159,10 +159,10 @@ func Test_validateMergeBlock(t *testing.T) {
 func Test_getBlkParentHashAndTD(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 	service, err := NewService(ctx, opts...)
@@ -211,7 +211,7 @@ func Test_getBlkParentHashAndTD(t *testing.T) {
 }

 func Test_validateTerminalBlockHash(t *testing.T) {
-	wrapped, err := blocks.WrappedExecutionPayload(&enginev1.ExecutionPayload{})
+	wrapped, err := wrapper.WrappedExecutionPayload(&enginev1.ExecutionPayload{})
 	require.NoError(t, err)
 	require.NoError(t, validateTerminalBlockHash(1, wrapped))

@@ -224,7 +224,7 @@ func Test_validateTerminalBlockHash(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 	require.ErrorContains(t, "parent hash does not match terminal block hash", validateTerminalBlockHash(1, wrapped))

-	wrapped, err = blocks.WrappedExecutionPayload(&enginev1.ExecutionPayload{
+	wrapped, err = wrapper.WrappedExecutionPayload(&enginev1.ExecutionPayload{
 		ParentHash: cfg.TerminalBlockHash.Bytes(),
 	})
 	require.NoError(t, err)
--- a/beacon-chain/blockchain/process_attestation.go
+++ b/beacon-chain/blockchain/process_attestation.go
@@ -5,12 +5,12 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1/attestation"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )

@@ -19,24 +19,23 @@ import (
 // The delay is handled by the caller in `processAttestations`.
 //
 // Spec pseudocode definition:
+//   def on_attestation(store: Store, attestation: Attestation) -> None:
+//    """
+//    Run ``on_attestation`` upon receiving a new ``attestation`` from either within a block or directly on the wire.
 //
-//	def on_attestation(store: Store, attestation: Attestation) -> None:
-//	 """
-//	 Run ``on_attestation`` upon receiving a new ``attestation`` from either within a block or directly on the wire.
+//    An ``attestation`` that is asserted as invalid may be valid at a later time,
+//    consider scheduling it for later processing in such case.
+//    """
+//    validate_on_attestation(store, attestation)
+//    store_target_checkpoint_state(store, attestation.data.target)
 //
-//	 An ``attestation`` that is asserted as invalid may be valid at a later time,
-//	 consider scheduling it for later processing in such case.
-//	 """
-//	 validate_on_attestation(store, attestation)
-//	 store_target_checkpoint_state(store, attestation.data.target)
+//    # Get state at the `target` to fully validate attestation
+//    target_state = store.checkpoint_states[attestation.data.target]
+//    indexed_attestation = get_indexed_attestation(target_state, attestation)
+//    assert is_valid_indexed_attestation(target_state, indexed_attestation)
 //
-//	 # Get state at the `target` to fully validate attestation
-//	 target_state = store.checkpoint_states[attestation.data.target]
-//	 indexed_attestation = get_indexed_attestation(target_state, attestation)
-//	 assert is_valid_indexed_attestation(target_state, indexed_attestation)
-//
-//	 # Update latest messages for attesting indices
-//	 update_latest_messages(store, indexed_attestation.attesting_indices, attestation)
+//    # Update latest messages for attesting indices
+//    update_latest_messages(store, indexed_attestation.attesting_indices, attestation)
 func (s *Service) OnAttestation(ctx context.Context, a *ethpb.Attestation) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.onAttestation")
 	defer span.End()
--- a/beacon-chain/blockchain/process_attestation_helpers.go
+++ b/beacon-chain/blockchain/process_attestation_helpers.go
@@ -6,15 +6,15 @@ import (
 	"strconv"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/async"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/async"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

 // getAttPreState retrieves the att pre state by either from the cache or the DB.
@@ -80,7 +80,7 @@ func (s *Service) verifyBeaconBlock(ctx context.Context, data *ethpb.Attestation
 	if err != nil {
 		return err
 	}
-	if err := blocks.BeaconBlockIsNil(b); err != nil {
+	if err := wrapper.BeaconBlockIsNil(b); err != nil {
 		return err
 	}
 	if b.Block().Slot() > data.Slot {
--- a/beacon-chain/blockchain/process_attestation_test.go
+++ b/beacon-chain/blockchain/process_attestation_test.go
@@ -5,31 +5,31 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

-func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
+func TestStore_OnAttestation_ErrorConditions_ProtoArray(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)

-	fc := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithForkChoiceStore(fc),
-		WithStateGen(stategen.New(beaconDB, fc)),
+		WithForkChoiceStore(protoarray.New()),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -128,6 +128,142 @@ func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
 	}
 }

+func TestStore_OnAttestation_ErrorConditions_DoublyLinkedTree(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+
+	opts := []Option{
+		WithDatabase(beaconDB),
+		WithForkChoiceStore(doublylinkedtree.New()),
+		WithStateGen(stategen.New(beaconDB)),
+	}
+	service, err := NewService(ctx, opts...)
+	require.NoError(t, err)
+
+	_, err = blockTree1(t, beaconDB, []byte{'g'})
+	require.NoError(t, err)
+
+	blkWithoutState := util.NewBeaconBlock()
+	blkWithoutState.Block.Slot = 0
+	util.SaveBlock(t, ctx, beaconDB, blkWithoutState)
+	BlkWithOutStateRoot, err := blkWithoutState.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blkWithStateBadAtt := util.NewBeaconBlock()
+	blkWithStateBadAtt.Block.Slot = 1
+	util.SaveBlock(t, ctx, beaconDB, blkWithStateBadAtt)
+	BlkWithStateBadAttRoot, err := blkWithStateBadAtt.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	s, err := util.NewBeaconState()
+	require.NoError(t, err)
+	require.NoError(t, s.SetSlot(100*params.BeaconConfig().SlotsPerEpoch))
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, BlkWithStateBadAttRoot))
+
+	blkWithValidState := util.NewBeaconBlock()
+	blkWithValidState.Block.Slot = 2
+	util.SaveBlock(t, ctx, beaconDB, blkWithValidState)
+
+	blkWithValidStateRoot, err := blkWithValidState.Block.HashTreeRoot()
+	require.NoError(t, err)
+	s, err = util.NewBeaconState()
+	require.NoError(t, err)
+	err = s.SetFork(&ethpb.Fork{
+		Epoch:           0,
+		CurrentVersion:  params.BeaconConfig().GenesisForkVersion,
+		PreviousVersion: params.BeaconConfig().GenesisForkVersion,
+	})
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, blkWithValidStateRoot))
+
+	tests := []struct {
+		name      string
+		a         *ethpb.Attestation
+		wantedErr string
+	}{
+		{
+			name:      "attestation's data slot not aligned with target vote",
+			a:         util.HydrateAttestation(&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: params.BeaconConfig().SlotsPerEpoch, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}}}),
+			wantedErr: "slot 32 does not match target epoch 0",
+		},
+		{
+			name:      "no pre state for attestations's target block",
+			a:         util.HydrateAttestation(&ethpb.Attestation{Data: &ethpb.AttestationData{Target: &ethpb.Checkpoint{Root: BlkWithOutStateRoot[:]}}}),
+			wantedErr: "could not get pre state for epoch 0",
+		},
+		{
+			name: "process attestation doesn't match current epoch",
+			a: util.HydrateAttestation(&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 100 * params.BeaconConfig().SlotsPerEpoch, Target: &ethpb.Checkpoint{Epoch: 100,
+				Root: BlkWithStateBadAttRoot[:]}}}),
+			wantedErr: "target epoch 100 does not match current epoch",
+		},
+		{
+			name:      "process nil attestation",
+			a:         nil,
+			wantedErr: "attestation can't be nil",
+		},
+		{
+			name:      "process nil field (a.Data) in attestation",
+			a:         &ethpb.Attestation{},
+			wantedErr: "attestation's data can't be nil",
+		},
+		{
+			name: "process nil field (a.Target) in attestation",
+			a: &ethpb.Attestation{
+				Data: &ethpb.AttestationData{
+					BeaconBlockRoot: make([]byte, fieldparams.RootLength),
+					Target:          nil,
+					Source:          &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)},
+				},
+				AggregationBits: make([]byte, 1),
+				Signature:       make([]byte, 96),
+			},
+			wantedErr: "attestation's target can't be nil",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := service.OnAttestation(ctx, tt.a)
+			if tt.wantedErr != "" {
+				assert.ErrorContains(t, tt.wantedErr, err)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestStore_OnAttestation_Ok_ProtoArray(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+
+	fcs := protoarray.New()
+	opts := []Option{
+		WithDatabase(beaconDB),
+		WithStateGen(stategen.New(beaconDB)),
+		WithForkChoiceStore(fcs),
+	}
+	service, err := NewService(ctx, opts...)
+	require.NoError(t, err)
+	genesisState, pks := util.DeterministicGenesisState(t, 64)
+	service.SetGenesisTime(time.Unix(time.Now().Unix()-int64(params.BeaconConfig().SecondsPerSlot), 0))
+	require.NoError(t, service.saveGenesisData(ctx, genesisState))
+	att, err := util.GenerateAttestations(genesisState, pks, 1, 0, false)
+	require.NoError(t, err)
+	tRoot := bytesutil.ToBytes32(att[0].Data.Target.Root)
+	copied := genesisState.Copy()
+	copied, err = transition.ProcessSlots(ctx, copied, 1)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, copied, tRoot))
+	ojc := &ethpb.Checkpoint{Epoch: 1, Root: tRoot[:]}
+	ofc := &ethpb.Checkpoint{Epoch: 1, Root: tRoot[:]}
+	state, blkRoot, err := prepareForkchoiceState(ctx, 0, tRoot, tRoot, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
+	require.NoError(t, service.OnAttestation(ctx, att[0]))
+}
+
 func TestStore_OnAttestation_Ok_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
@@ -135,7 +271,7 @@ func TestStore_OnAttestation_Ok_DoublyLinkedTree(t *testing.T) {
 	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 	service, err := NewService(ctx, opts...)
@@ -164,7 +300,7 @@ func TestStore_SaveCheckpointState(t *testing.T) {

 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, doublylinkedtree.New())),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -226,7 +362,7 @@ func TestStore_UpdateCheckpointState(t *testing.T) {

 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, doublylinkedtree.New())),
+		WithStateGen(stategen.New(beaconDB)),
 	}
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
@@ -256,7 +392,7 @@ func TestStore_UpdateCheckpointState(t *testing.T) {

 	cached, err = service.checkpointStateCache.StateByCheckpoint(newCheckpoint)
 	require.NoError(t, err)
-	require.DeepSSZEqual(t, returned.ToProtoUnsafe(), cached.ToProtoUnsafe())
+	require.DeepSSZEqual(t, returned.InnerStateUnsafe(), cached.InnerStateUnsafe())
 }

 func TestAttEpoch_MatchPrevEpoch(t *testing.T) {
@@ -325,6 +461,37 @@ func TestVerifyBeaconBlock_OK(t *testing.T) {
 	assert.NoError(t, service.verifyBeaconBlock(ctx, d), "Did not receive the wanted error")
 }

+func TestVerifyFinalizedConsistency_InconsistentRoot_ProtoArray(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+
+	fcs := protoarray.New()
+	opts := []Option{
+		WithDatabase(beaconDB),
+		WithStateGen(stategen.New(beaconDB)),
+		WithForkChoiceStore(fcs),
+	}
+	service, err := NewService(ctx, opts...)
+	require.NoError(t, err)
+
+	b32 := util.NewBeaconBlock()
+	b32.Block.Slot = 32
+	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b32)
+	r32, err := b32.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	require.NoError(t, service.ForkChoicer().UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: 1}))
+	b33 := util.NewBeaconBlock()
+	b33.Block.Slot = 33
+	b33.Block.ParentRoot = r32[:]
+	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b33)
+	r33, err := b33.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	err = service.VerifyFinalizedConsistency(context.Background(), r33[:])
+	require.ErrorContains(t, "Root and finalized store are not consistent", err)
+}
+
 func TestVerifyFinalizedConsistency_InconsistentRoot_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
@@ -332,7 +499,7 @@ func TestVerifyFinalizedConsistency_InconsistentRoot_DoublyLinkedTree(t *testing
 	fcs := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithStateGen(stategen.New(beaconDB, fcs)),
+		WithStateGen(stategen.New(beaconDB)),
 		WithForkChoiceStore(fcs),
 	}
 	service, err := NewService(ctx, opts...)
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -6,28 +6,29 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/async/event"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	coreTime "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/time"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/features"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	consensusblocks "github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/crypto/bls"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v3/monitoring/tracing"
-	ethpbv1 "github.com/prysmaticlabs/prysm/v3/proto/eth/v1"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1/attestation"
-	"github.com/prysmaticlabs/prysm/v3/runtime/version"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/async/event"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	coreTime "github.com/prysmaticlabs/prysm/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/features"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/crypto/bls"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/monitoring/tracing"
+	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpbv1 "github.com/prysmaticlabs/prysm/proto/eth/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
+	"github.com/prysmaticlabs/prysm/runtime/version"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )

@@ -45,60 +46,58 @@ var initialSyncBlockCacheSize = uint64(2 * params.BeaconConfig().SlotsPerEpoch)
 // computation in this method and methods it calls into.
 //
 // Spec pseudocode definition:
+//   def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
+//    block = signed_block.message
+//    # Parent block must be known
+//    assert block.parent_root in store.block_states
+//    # Make a copy of the state to avoid mutability issues
+//    pre_state = copy(store.block_states[block.parent_root])
+//    # Blocks cannot be in the future. If they are, their consideration must be delayed until the are in the past.
+//    assert get_current_slot(store) >= block.slot
 //
-//	def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
-//	 block = signed_block.message
-//	 # Parent block must be known
-//	 assert block.parent_root in store.block_states
-//	 # Make a copy of the state to avoid mutability issues
-//	 pre_state = copy(store.block_states[block.parent_root])
-//	 # Blocks cannot be in the future. If they are, their consideration must be delayed until the are in the past.
-//	 assert get_current_slot(store) >= block.slot
+//    # Check that block is later than the finalized epoch slot (optimization to reduce calls to get_ancestor)
+//    finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
+//    assert block.slot > finalized_slot
+//    # Check block is a descendant of the finalized block at the checkpoint finalized slot
+//    assert get_ancestor(store, block.parent_root, finalized_slot) == store.finalized_checkpoint.root
 //
-//	 # Check that block is later than the finalized epoch slot (optimization to reduce calls to get_ancestor)
-//	 finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
-//	 assert block.slot > finalized_slot
-//	 # Check block is a descendant of the finalized block at the checkpoint finalized slot
-//	 assert get_ancestor(store, block.parent_root, finalized_slot) == store.finalized_checkpoint.root
+//    # Check the block is valid and compute the post-state
+//    state = pre_state.copy()
+//    state_transition(state, signed_block, True)
+//    # Add new block to the store
+//    store.blocks[hash_tree_root(block)] = block
+//    # Add new state for this block to the store
+//    store.block_states[hash_tree_root(block)] = state
 //
-//	 # Check the block is valid and compute the post-state
-//	 state = pre_state.copy()
-//	 state_transition(state, signed_block, True)
-//	 # Add new block to the store
-//	 store.blocks[hash_tree_root(block)] = block
-//	 # Add new state for this block to the store
-//	 store.block_states[hash_tree_root(block)] = state
+//    # Update justified checkpoint
+//    if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
+//        if state.current_justified_checkpoint.epoch > store.best_justified_checkpoint.epoch:
+//            store.best_justified_checkpoint = state.current_justified_checkpoint
+//        if should_update_justified_checkpoint(store, state.current_justified_checkpoint):
+//            store.justified_checkpoint = state.current_justified_checkpoint
 //
-//	 # Update justified checkpoint
-//	 if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
-//	     if state.current_justified_checkpoint.epoch > store.best_justified_checkpoint.epoch:
-//	         store.best_justified_checkpoint = state.current_justified_checkpoint
-//	     if should_update_justified_checkpoint(store, state.current_justified_checkpoint):
-//	         store.justified_checkpoint = state.current_justified_checkpoint
+//    # Update finalized checkpoint
+//    if state.finalized_checkpoint.epoch > store.finalized_checkpoint.epoch:
+//        store.finalized_checkpoint = state.finalized_checkpoint
 //
-//	 # Update finalized checkpoint
-//	 if state.finalized_checkpoint.epoch > store.finalized_checkpoint.epoch:
-//	     store.finalized_checkpoint = state.finalized_checkpoint
+//        # Potentially update justified if different from store
+//        if store.justified_checkpoint != state.current_justified_checkpoint:
+//            # Update justified if new justified is later than store justified
+//            if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
+//                store.justified_checkpoint = state.current_justified_checkpoint
+//                return
 //
-//	     # Potentially update justified if different from store
-//	     if store.justified_checkpoint != state.current_justified_checkpoint:
-//	         # Update justified if new justified is later than store justified
-//	         if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
-//	             store.justified_checkpoint = state.current_justified_checkpoint
-//	             return
-//
-//	         # Update justified if store justified is not in chain with finalized checkpoint
-//	         finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
-//	         ancestor_at_finalized_slot = get_ancestor(store, store.justified_checkpoint.root, finalized_slot)
-//	         if ancestor_at_finalized_slot != store.finalized_checkpoint.root:
-//	             store.justified_checkpoint = state.current_justified_checkpoint
+//            # Update justified if store justified is not in chain with finalized checkpoint
+//            finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
+//            ancestor_at_finalized_slot = get_ancestor(store, store.justified_checkpoint.root, finalized_slot)
+//            if ancestor_at_finalized_slot != store.finalized_checkpoint.root:
+//                store.justified_checkpoint = state.current_justified_checkpoint
 func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlock, blockRoot [32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.onBlock")
 	defer span.End()
-	if err := consensusblocks.BeaconBlockIsNil(signed); err != nil {
+	if err := wrapper.BeaconBlockIsNil(signed); err != nil {
 		return invalidBlock{error: err}
 	}
-	startTime := time.Now()
 	b := signed.Block()

 	preState, err := s.getBlockPreState(ctx, b)
@@ -116,13 +115,10 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 	if err != nil {
 		return err
 	}
-	stateTransitionStartTime := time.Now()
 	postState, err := transition.ExecuteStateTransition(ctx, preState, signed)
 	if err != nil {
 		return invalidBlock{error: err}
 	}
-	stateTransitionProcessingTime.Observe(float64(time.Since(stateTransitionStartTime).Milliseconds()))
-
 	postStateVersion, postStateHeader, err := getStateVersionAndPayload(postState)
 	if err != nil {
 		return err
@@ -140,16 +136,9 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 		return err
 	}

-	if err := s.insertBlockToForkchoiceStore(ctx, signed.Block(), blockRoot, postState); err != nil {
+	if err := s.insertBlockAndAttestationsToForkChoiceStore(ctx, signed.Block(), blockRoot, postState); err != nil {
 		return errors.Wrapf(err, "could not insert block %d to fork choice store", signed.Block().Slot())
 	}
-	if err := s.handleBlockAttestations(ctx, signed.Block(), postState); err != nil {
-		return errors.Wrap(err, "could not handle block's attestations")
-	}
-	if err := s.handleBlockBLSToExecChanges(signed.Block()); err != nil {
-		return errors.Wrap(err, "could not handle block's BLSToExecutionChanges")
-	}
-
 	s.InsertSlashingsToForkChoiceStore(ctx, signed.Block().Body().AttesterSlashings())
 	if isValidPayload {
 		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, blockRoot); err != nil {
@@ -190,14 +179,10 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 		msg := fmt.Sprintf("could not read balances for state w/ justified checkpoint %#x", justified.Root)
 		return errors.Wrap(err, msg)
 	}
-
-	start := time.Now()
 	headRoot, err := s.cfg.ForkChoiceStore.Head(ctx, balances)
 	if err != nil {
 		log.WithError(err).Warn("Could not update head")
 	}
-	newBlockHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
-
 	if err := s.notifyEngineIfChangedHead(ctx, headRoot); err != nil {
 		return err
 	}
@@ -252,13 +237,12 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 		}
 		go func() {
 			// Send an event regarding the new finalized checkpoint over a common event feed.
-			stateRoot := signed.Block().StateRoot()
 			s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 				Type: statefeed.FinalizedCheckpoint,
 				Data: &ethpbv1.EventFinalizedCheckpoint{
 					Epoch:               postState.FinalizedCheckpoint().Epoch,
 					Block:               postState.FinalizedCheckpoint().Root,
-					State:               stateRoot[:],
+					State:               signed.Block().StateRoot(),
 					ExecutionOptimistic: isOptimistic,
 				},
 			})
@@ -275,18 +259,14 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo

 	}
 	defer reportAttestationInclusion(b)
-	if err := s.handleEpochBoundary(ctx, postState); err != nil {
-		return err
-	}
-	onBlockProcessingTime.Observe(float64(time.Since(startTime).Milliseconds()))
-	return nil
+	return s.handleEpochBoundary(ctx, postState)
 }

-func getStateVersionAndPayload(st state.BeaconState) (int, interfaces.ExecutionData, error) {
+func getStateVersionAndPayload(st state.BeaconState) (int, *enginev1.ExecutionPayloadHeader, error) {
 	if st == nil {
 		return 0, nil, errors.New("nil state")
 	}
-	var preStateHeader interfaces.ExecutionData
+	var preStateHeader *enginev1.ExecutionPayloadHeader
 	var err error
 	preStateVersion := st.Version()
 	switch preStateVersion {
@@ -313,7 +293,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 		return errWrongBlockCount
 	}

-	if err := consensusblocks.BeaconBlockIsNil(blks[0]); err != nil {
+	if err := wrapper.BeaconBlockIsNil(blks[0]); err != nil {
 		return invalidBlock{error: err}
 	}
 	b := blks[0].Block()
@@ -322,7 +302,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 	if err := s.verifyBlkPreState(ctx, b); err != nil {
 		return err
 	}
-	preState, err := s.cfg.StateGen.StateByRootInitialSync(ctx, b.ParentRoot())
+	preState, err := s.cfg.StateGen.StateByRootInitialSync(ctx, bytesutil.ToBytes32(b.ParentRoot()))
 	if err != nil {
 		return err
 	}
@@ -337,10 +317,14 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac

 	jCheckpoints := make([]*ethpb.Checkpoint, len(blks))
 	fCheckpoints := make([]*ethpb.Checkpoint, len(blks))
-	sigSet := bls.NewSet()
+	sigSet := &bls.SignatureBatch{
+		Signatures: [][]byte{},
+		PublicKeys: []bls.PublicKey{},
+		Messages:   [][32]byte{},
+	}
 	type versionAndHeader struct {
 		version int
-		header  interfaces.ExecutionData
+		header  *enginev1.ExecutionPayloadHeader
 	}
 	preVersionAndHeaders := make([]*versionAndHeader, len(blks))
 	postVersionAndHeaders := make([]*versionAndHeader, len(blks))
@@ -377,13 +361,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 		}
 		sigSet.Join(set)
 	}
-
-	var verify bool
-	if features.Get().EnableVerboseSigVerification {
-		verify, err = sigSet.VerifyVerbosely()
-	} else {
-		verify, err = sigSet.Verify()
-	}
+	verify, err := sigSet.Verify()
 	if err != nil {
 		return invalidBlock{error: err}
 	}
@@ -517,13 +495,13 @@ func (s *Service) handleEpochBoundary(ctx context.Context, postState state.Beaco
 	return nil
 }

-// This feeds in the block to fork choice store. It's allows fork choice store
+// This feeds in the block and block's attestations to fork choice store. It's allows fork choice store
 // to gain information on the most current chain.
-func (s *Service) insertBlockToForkchoiceStore(ctx context.Context, blk interfaces.BeaconBlock, root [32]byte, st state.BeaconState) error {
-	ctx, span := trace.StartSpan(ctx, "blockChain.insertBlockToForkchoiceStore")
+func (s *Service) insertBlockAndAttestationsToForkChoiceStore(ctx context.Context, blk interfaces.BeaconBlock, root [32]byte, st state.BeaconState) error {
+	ctx, span := trace.StartSpan(ctx, "blockChain.insertBlockAndAttestationsToForkChoiceStore")
 	defer span.End()

-	if !s.cfg.ForkChoiceStore.HasNode(blk.ParentRoot()) {
+	if !s.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(blk.ParentRoot())) {
 		fCheckpoint := st.FinalizedCheckpoint()
 		jCheckpoint := st.CurrentJustifiedCheckpoint()
 		if err := s.fillInForkChoiceMissingBlocks(ctx, blk, fCheckpoint, jCheckpoint); err != nil {
@@ -531,12 +509,9 @@ func (s *Service) insertBlockToForkchoiceStore(ctx context.Context, blk interfac
 		}
 	}

-	return s.cfg.ForkChoiceStore.InsertNode(ctx, st, root)
-}
-
-// This feeds in the attestations included in the block to fork choice store. It's allows fork choice store
-// to gain information on the most current chain.
-func (s *Service) handleBlockAttestations(ctx context.Context, blk interfaces.BeaconBlock, st state.BeaconState) error {
+	if err := s.cfg.ForkChoiceStore.InsertNode(ctx, st, root); err != nil {
+		return err
+	}
 	// Feed in block's attestations to fork choice store.
 	for _, a := range blk.Body().Attestations() {
 		committee, err := helpers.BeaconCommitteeFromState(ctx, st, a.Data.Slot, a.Data.CommitteeIndex)
@@ -547,28 +522,7 @@ func (s *Service) handleBlockAttestations(ctx context.Context, blk interfaces.Be
 		if err != nil {
 			return err
 		}
-		r := bytesutil.ToBytes32(a.Data.BeaconBlockRoot)
-		if s.cfg.ForkChoiceStore.HasNode(r) {
-			s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indices, r, a.Data.Target.Epoch)
-		} else if err := s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func (s *Service) handleBlockBLSToExecChanges(blk interfaces.BeaconBlock) error {
-	if blk.Version() < version.Capella {
-		return nil
-	}
-	changes, err := blk.Body().BLSToExecutionChanges()
-	if err != nil {
-		return errors.Wrap(err, "could not get BLSToExecutionChanges")
-	}
-	for _, change := range changes {
-		if err := s.cfg.BLSToExecPool.MarkIncluded(change); err != nil {
-			return errors.Wrap(err, "could not mark BLSToExecutionChange as included")
-		}
+		s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indices, bytesutil.ToBytes32(a.Data.BeaconBlockRoot), a.Data.Target.Epoch)
 	}
 	return nil
 }
@@ -625,7 +579,7 @@ func (s *Service) pruneCanonicalAttsFromPool(ctx context.Context, r [32]byte, b
 }

 // validateMergeTransitionBlock validates the merge transition block.
-func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion int, stateHeader interfaces.ExecutionData, blk interfaces.SignedBeaconBlock) error {
+func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion int, stateHeader *enginev1.ExecutionPayloadHeader, blk interfaces.SignedBeaconBlock) error {
 	// Skip validation if block is older than Bellatrix.
 	if blocks.IsPreBellatrixVersion(blk.Block().Version()) {
 		return nil
@@ -636,7 +590,7 @@ func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion
 	if err != nil {
 		return invalidBlock{error: err}
 	}
-	isEmpty, err := consensusblocks.IsEmptyExecutionData(payload)
+	isEmpty, err := wrapper.IsEmptyExecutionData(payload)
 	if err != nil {
 		return err
 	}
@@ -652,7 +606,11 @@ func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion

 	// Skip validation if the block is not a merge transition block.
 	// To reach here. The payload must be non-empty. If the state header is empty then it's at transition.
-	empty, err := consensusblocks.IsEmptyExecutionData(stateHeader)
+	wh, err := wrapper.WrappedExecutionPayloadHeader(stateHeader)
+	if err != nil {
+		return err
+	}
+	empty, err := wrapper.IsEmptyExecutionData(wh)
 	if err != nil {
 		return err
 	}
@@ -683,8 +641,20 @@ func (s *Service) fillMissingPayloadIDRoutine(ctx context.Context, stateFeed *ev
 		for {
 			select {
 			case ti := <-ticker.C:
-				if err := s.fillMissingBlockPayloadId(ctx, ti); err != nil {
-					log.WithError(err).Error("Could not fill missing payload ID")
+				if !atHalfSlot(ti) {
+					continue
+				}
+				_, id, has := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(s.CurrentSlot() + 1)
+				// There exists proposer for next slot, but we haven't called fcu w/ payload attribute yet.
+				if has && id == [8]byte{} {
+					if _, err := s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
+						headState: s.headState(ctx),
+						headRoot:  s.headRoot(),
+						headBlock: s.headBlock().Block(),
+					}); err != nil {
+						log.WithError(err).Error("Could not prepare payload on empty ID")
+					}
+					missedPayloadIDFilledCount.Inc()
 				}
 			case <-s.ctx.Done():
 				log.Debug("Context closed, exiting routine")
@@ -699,31 +669,3 @@ func atHalfSlot(t time.Time) bool {
 	s := params.BeaconConfig().SecondsPerSlot
 	return uint64(t.Second())%s == s/2
 }
-
-func (s *Service) fillMissingBlockPayloadId(ctx context.Context, ti time.Time) error {
-	if !atHalfSlot(ti) {
-		return nil
-	}
-	if s.CurrentSlot() == s.cfg.ForkChoiceStore.HighestReceivedBlockSlot() {
-		return nil
-	}
-	// Head root should be empty when retrieving proposer index for the next slot.
-	_, id, has := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(s.CurrentSlot()+1, [32]byte{} /* head root */)
-	// There exists proposer for next slot, but we haven't called fcu w/ payload attribute yet.
-	if has && id == [8]byte{} {
-		missedPayloadIDFilledCount.Inc()
-		headBlock, err := s.headBlock()
-		if err != nil {
-			return err
-		} else {
-			if _, err := s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
-				headState: s.headState(ctx),
-				headRoot:  s.headRoot(),
-				headBlock: headBlock.Block(),
-			}); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
--- a/beacon-chain/blockchain/process_block_helpers.go
+++ b/beacon-chain/blockchain/process_block_helpers.go
@@ -6,17 +6,19 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	mathutil "github.com/prysmaticlabs/prysm/v3/math"
-	"github.com/prysmaticlabs/prysm/v3/monitoring/tracing"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	mathutil "github.com/prysmaticlabs/prysm/math"
+	"github.com/prysmaticlabs/prysm/monitoring/tracing"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )

@@ -37,7 +39,7 @@ func (s *Service) getBlockPreState(ctx context.Context, b interfaces.BeaconBlock
 		return nil, err
 	}

-	preState, err := s.cfg.StateGen.StateByRoot(ctx, b.ParentRoot())
+	preState, err := s.cfg.StateGen.StateByRoot(ctx, bytesutil.ToBytes32(b.ParentRoot()))
 	if err != nil {
 		return nil, errors.Wrapf(err, "could not get pre state for slot %d", b.Slot())
 	}
@@ -63,7 +65,7 @@ func (s *Service) verifyBlkPreState(ctx context.Context, b interfaces.BeaconBloc
 	ctx, span := trace.StartSpan(ctx, "blockChain.verifyBlkPreState")
 	defer span.End()

-	parentRoot := b.ParentRoot()
+	parentRoot := bytesutil.ToBytes32(b.ParentRoot())
 	// Loosen the check to HasBlock because state summary gets saved in batches
 	// during initial syncing. There's no risk given a state summary object is just a
 	// a subset of the block object.
@@ -71,7 +73,7 @@ func (s *Service) verifyBlkPreState(ctx context.Context, b interfaces.BeaconBloc
 		return errors.New("could not reconstruct parent state")
 	}

-	if err := s.VerifyFinalizedBlkDescendant(ctx, parentRoot); err != nil {
+	if err := s.VerifyFinalizedBlkDescendant(ctx, bytesutil.ToBytes32(b.ParentRoot())); err != nil {
 		return err
 	}

@@ -133,21 +135,11 @@ func (s *Service) verifyBlkFinalizedSlot(b interfaces.BeaconBlock) error {
 }

 // updateFinalized saves the init sync blocks, finalized checkpoint, migrates
-// to cold old states and saves the last validated checkpoint to DB. It returns
-// early if the new checkpoint is older than the one on db.
+// to cold old states and saves the last validated checkpoint to DB
 func (s *Service) updateFinalized(ctx context.Context, cp *ethpb.Checkpoint) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.updateFinalized")
 	defer span.End()

-	// return early if new checkpoint is not newer than the one in DB
-	currentFinalized, err := s.cfg.BeaconDB.FinalizedCheckpoint(ctx)
-	if err != nil {
-		return err
-	}
-	if cp.Epoch <= currentFinalized.Epoch {
-		return nil
-	}
-
 	// Blocks need to be saved so that we can retrieve finalized block from
 	// DB when migrating states.
 	if err := s.cfg.BeaconDB.SaveBlocks(ctx, s.getInitSyncBlocks()); err != nil {
@@ -161,7 +153,7 @@ func (s *Service) updateFinalized(ctx context.Context, cp *ethpb.Checkpoint) err

 	fRoot := bytesutil.ToBytes32(cp.Root)
 	optimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(fRoot)
-	if err != nil && !errors.Is(err, doublylinkedtree.ErrNilNode) {
+	if err != nil && err != protoarray.ErrUnknownNodeRoot && err != doublylinkedtree.ErrNilNode {
 		return err
 	}
 	if !optimistic {
@@ -170,30 +162,24 @@ func (s *Service) updateFinalized(ctx context.Context, cp *ethpb.Checkpoint) err
 			return err
 		}
 	}
-	go func() {
-		// We do not pass in the parent context from the method as this method call
-		// is meant to be asynchronous and run in the background rather than being
-		// tied to the execution of a block.
-		if err := s.cfg.StateGen.MigrateToCold(s.ctx, fRoot); err != nil {
-			log.WithError(err).Error("could not migrate to cold")
-		}
-	}()
+	if err := s.cfg.StateGen.MigrateToCold(ctx, fRoot); err != nil {
+		return errors.Wrap(err, "could not migrate to cold")
+	}
 	return nil
 }

 // ancestor returns the block root of an ancestry block from the input block root.
 //
 // Spec pseudocode definition:
-//
-//	def get_ancestor(store: Store, root: Root, slot: Slot) -> Root:
-//	 block = store.blocks[root]
-//	 if block.slot > slot:
-//	     return get_ancestor(store, block.parent_root, slot)
-//	 elif block.slot == slot:
-//	     return root
-//	 else:
-//	     # root is older than queried slot, thus a skip slot. Return most recent root prior to slot
-//	     return root
+//   def get_ancestor(store: Store, root: Root, slot: Slot) -> Root:
+//    block = store.blocks[root]
+//    if block.slot > slot:
+//        return get_ancestor(store, block.parent_root, slot)
+//    elif block.slot == slot:
+//        return root
+//    else:
+//        # root is older than queried slot, thus a skip slot. Return most recent root prior to slot
+//        return root
 func (s *Service) ancestor(ctx context.Context, root []byte, slot types.Slot) ([]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ancestor")
 	defer span.End()
@@ -245,7 +231,7 @@ func (s *Service) ancestorByDB(ctx context.Context, r [32]byte, slot types.Slot)
 		return r[:], nil
 	}

-	return s.ancestorByDB(ctx, b.ParentRoot(), slot)
+	return s.ancestorByDB(ctx, bytesutil.ToBytes32(b.ParentRoot()), slot)
 }

 // This retrieves missing blocks from DB (ie. the blocks that couldn't be received over sync) and inserts them to fork choice store.
@@ -263,7 +249,7 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfa
 	pendingNodes = append(pendingNodes, &forkchoicetypes.BlockAndCheckpoints{Block: blk,
 		JustifiedCheckpoint: jCheckpoint, FinalizedCheckpoint: fCheckpoint})
 	// As long as parent node is not in fork choice store, and parent node is in DB.
-	root := blk.ParentRoot()
+	root := bytesutil.ToBytes32(blk.ParentRoot())
 	for !s.cfg.ForkChoiceStore.HasNode(root) && s.cfg.BeaconDB.HasBlock(ctx, root) {
 		b, err := s.getBlock(ctx, root)
 		if err != nil {
@@ -272,7 +258,7 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfa
 		if b.Block().Slot() <= fSlot {
 			break
 		}
-		root = b.Block().ParentRoot()
+		root = bytesutil.ToBytes32(b.Block().ParentRoot())
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
 			JustifiedCheckpoint: jCheckpoint,
 			FinalizedCheckpoint: fCheckpoint}
@@ -281,7 +267,7 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfa
 	if len(pendingNodes) == 1 {
 		return nil
 	}
-	if root != s.ensureRootNotZeros(finalized.Root) && !s.ForkChoicer().HasNode(root) {
+	if root != s.ensureRootNotZeros(finalized.Root) {
 		return errNotDescendantOfFinalized
 	}
 	return s.cfg.ForkChoiceStore.InsertOptimisticChain(ctx, pendingNodes)
@@ -316,6 +302,23 @@ func (s *Service) insertFinalizedDeposits(ctx context.Context, fRoot [32]byte) e
 	return nil
 }

+// The deletes input attestations from the attestation pool, so proposers don't include them in a block for the future.
+func (s *Service) deletePoolAtts(atts []*ethpb.Attestation) error {
+	for _, att := range atts {
+		if helpers.IsAggregated(att) {
+			if err := s.cfg.AttPool.DeleteAggregatedAttestation(att); err != nil {
+				return err
+			}
+		} else {
+			if err := s.cfg.AttPool.DeleteUnaggregatedAttestation(att); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 // This ensures that the input root defaults to using genesis root instead of zero hashes. This is needed for handling
 // fork choice justification routine.
 func (s *Service) ensureRootNotZeros(root [32]byte) [32]byte {
--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
--- a/beacon-chain/blockchain/receive_attestation.go
+++ b/beacon-chain/blockchain/receive_attestation.go
@@ -7,14 +7,14 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/async/event"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/async/event"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -122,10 +122,12 @@ func (s *Service) spawnProcessAttestationsRoutine(stateFeed *event.Feed) {
 			case <-st.C():
 				if err := s.ForkChoicer().NewSlot(s.ctx, s.CurrentSlot()); err != nil {
 					log.WithError(err).Error("Could not process new slot")
+					return
 				}

 				if err := s.UpdateHead(s.ctx); err != nil {
 					log.WithError(err).Error("Could not process attestations and update head")
+					return
 				}
 			}
 		}
@@ -135,26 +137,27 @@ func (s *Service) spawnProcessAttestationsRoutine(stateFeed *event.Feed) {
 // UpdateHead updates the canonical head of the chain based on information from fork-choice attestations and votes.
 // It requires no external inputs.
 func (s *Service) UpdateHead(ctx context.Context) error {
+	// Continue when there's no fork choice attestation, there's nothing to process and update head.
+	// This covers the condition when the node is still initial syncing to the head of the chain.
+	if s.cfg.AttPool.ForkchoiceAttestationCount() == 0 {
+		return nil
+	}
+
 	// Only one process can process attestations and update head at a time.
 	s.processAttestationsLock.Lock()
 	defer s.processAttestationsLock.Unlock()

-	start := time.Now()
 	s.processAttestations(ctx)
-	processAttsElapsedTime.Observe(float64(time.Since(start).Milliseconds()))

 	justified := s.ForkChoicer().JustifiedCheckpoint()
 	balances, err := s.justifiedBalances.get(ctx, justified.Root)
 	if err != nil {
 		return err
 	}
-	start = time.Now()
 	newHeadRoot, err := s.cfg.ForkChoiceStore.Head(ctx, balances)
 	if err != nil {
-		log.WithError(err).Error("Could not compute head from new attestations")
+		log.WithError(err).Warn("Resolving fork due to new attestation")
 	}
-	newAttHeadElapsedTime.Observe(float64(time.Since(start).Milliseconds()))
-
 	s.headLock.RLock()
 	if s.headRoot() != newHeadRoot {
 		log.WithFields(logrus.Fields{
--- a/beacon-chain/blockchain/receive_attestation_test.go
+++ b/beacon-chain/blockchain/receive_attestation_test.go
@@ -5,21 +5,21 @@ import (
 	"testing"
 	"time"

-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/attestations"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	prysmTime "github.com/prysmaticlabs/prysm/v3/time"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -137,7 +137,7 @@ func TestNotifyEngineIfChangedHead(t *testing.T) {
 	invalidStateErr := "Could not get state from db"
 	require.LogsDoNotContain(t, hook, invalidStateErr)
 	require.LogsDoNotContain(t, hook, hookErr)
-	gb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	gb, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	require.NoError(t, service.saveInitSyncBlock(ctx, [32]byte{'a'}, gb))
 	require.NoError(t, service.notifyEngineIfChangedHead(ctx, [32]byte{'a'}))
@@ -152,18 +152,19 @@ func TestNotifyEngineIfChangedHead(t *testing.T) {
 	// Block in Cache
 	b := util.NewBeaconBlock()
 	b.Block.Slot = 2
-	wsb, err := blocks.NewSignedBeaconBlock(b)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
 	require.NoError(t, err)
 	r1, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
 	require.NoError(t, service.saveInitSyncBlock(ctx, r1, wsb))
 	st, _ := util.DeterministicGenesisState(t, 1)
 	service.head = &head{
+		slot:  1,
 		root:  r1,
 		block: wsb,
 		state: st,
 	}
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(2, 1, [8]byte{1}, [32]byte{2})
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(2, 1, [8]byte{1})
 	require.NoError(t, service.notifyEngineIfChangedHead(ctx, r1))
 	require.LogsDoNotContain(t, hook, invalidStateErr)
 	require.LogsDoNotContain(t, hook, hookErr)
@@ -176,15 +177,16 @@ func TestNotifyEngineIfChangedHead(t *testing.T) {
 	require.NoError(t, err)
 	st, _ = util.DeterministicGenesisState(t, 1)
 	service.head = &head{
+		slot:  1,
 		root:  r1,
 		block: wsb,
 		state: st,
 	}
-	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(2, 1, [8]byte{1}, [32]byte{2})
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(2, 1, [8]byte{1})
 	require.NoError(t, service.notifyEngineIfChangedHead(ctx, r1))
 	require.LogsDoNotContain(t, hook, invalidStateErr)
 	require.LogsDoNotContain(t, hook, hookErr)
-	vId, payloadID, has := service.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(2, [32]byte{2})
+	vId, payloadID, has := service.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(2)
 	require.Equal(t, true, has)
 	require.Equal(t, types.ValidatorIndex(1), vId)
 	require.Equal(t, [8]byte{1}, payloadID)
@@ -198,7 +200,7 @@ func TestNotifyEngineIfChangedHead(t *testing.T) {
 func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	ctx := context.Background()
 	opts := testServiceOptsWithDB(t)
-	fcs := doublylinkedtree.New()
+	fcs := protoarray.New()
 	opts = append(opts,
 		WithAttestationPool(attestations.NewPool()),
 		WithStateNotifier(&mockBeaconNode{}),
@@ -216,7 +218,7 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	require.NoError(t, err)
 	tRoot, err := blk.Block.HashTreeRoot()
 	require.NoError(t, err)
-	wsb, err := blocks.NewSignedBeaconBlock(blk)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 	require.NoError(t, service.onBlock(ctx, wsb, tRoot))
 	copied, err = service.cfg.StateGen.StateByRoot(ctx, tRoot)
@@ -224,11 +226,11 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	require.Equal(t, 2, fcs.NodeCount())
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))

-	// Generate attestations for this block in Slot 1
+	// Generate attestatios for this block in Slot 1
 	atts, err := util.GenerateAttestations(copied, pks, 1, 1, false)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.AttPool.SaveForkchoiceAttestations(atts))
-	// Verify the target is in forkchoice
+	// Verify the target is in forchoice
 	require.Equal(t, true, fcs.HasNode(bytesutil.ToBytes32(atts[0].Data.BeaconBlockRoot)))

 	// Insert a new block to forkchoice
@@ -251,52 +253,3 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	require.Equal(t, 0, len(service.cfg.AttPool.ForkchoiceAttestations())) // Validate att pool is empty
 	require.Equal(t, tRoot, service.head.root)                             // Validate head is the new one
 }
-
-func TestService_UpdateHead_NoAtts(t *testing.T) {
-	ctx := context.Background()
-	opts := testServiceOptsWithDB(t)
-	fcs := doublylinkedtree.New()
-	opts = append(opts,
-		WithAttestationPool(attestations.NewPool()),
-		WithStateNotifier(&mockBeaconNode{}),
-		WithForkChoiceStore(fcs),
-	)
-
-	service, err := NewService(ctx, opts...)
-	require.NoError(t, err)
-	service.genesisTime = prysmTime.Now().Add(-2 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
-	genesisState, pks := util.DeterministicGenesisState(t, 64)
-	require.NoError(t, service.saveGenesisData(ctx, genesisState))
-	copied := genesisState.Copy()
-	// Generate a new block
-	blk, err := util.GenerateFullBlock(copied, pks, util.DefaultBlockGenConfig(), 1)
-	require.NoError(t, err)
-	tRoot, err := blk.Block.HashTreeRoot()
-	require.NoError(t, err)
-	wsb, err := blocks.NewSignedBeaconBlock(blk)
-	require.NoError(t, err)
-	require.NoError(t, service.onBlock(ctx, wsb, tRoot))
-	require.Equal(t, 2, fcs.NodeCount())
-	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
-	require.Equal(t, tRoot, service.head.root)
-
-	// Insert a new block to forkchoice
-	ojc := &ethpb.Checkpoint{Epoch: 0, Root: params.BeaconConfig().ZeroHash[:]}
-	b, err := util.GenerateFullBlock(genesisState, pks, util.DefaultBlockGenConfig(), 2)
-	require.NoError(t, err)
-	b.Block.ParentRoot = service.originBlockRoot[:]
-	r, err := b.Block.HashTreeRoot()
-	require.NoError(t, err)
-	util.SaveBlock(t, ctx, service.cfg.BeaconDB, b)
-	state, blkRoot, err := prepareForkchoiceState(ctx, 2, r, service.originBlockRoot, [32]byte{'b'}, ojc, ojc)
-	require.NoError(t, err)
-	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
-	require.Equal(t, 3, fcs.NodeCount())
-
-	require.Equal(t, 0, service.cfg.AttPool.ForkchoiceAttestationCount())
-	require.NoError(t, err, service.UpdateHead(ctx))
-
-	require.Equal(t, 0, len(service.cfg.AttPool.ForkchoiceAttestations())) // Validate att pool is empty
-	require.Equal(t, r, service.head.root)                                 // Validate head is the new one
-
-}
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -4,14 +4,14 @@ import (
 	"context"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/monitoring/tracing"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/monitoring/tracing"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )

@@ -32,17 +32,14 @@ type SlashingReceiver interface {

 // ReceiveBlock is a function that defines the operations (minus pubsub)
 // that are performed on a received block. The operations consist of:
-//  1. Validate block, apply state transition and update checkpoints
-//  2. Apply fork choice to the processed block
-//  3. Save latest head info
+//   1. Validate block, apply state transition and update checkpoints
+//   2. Apply fork choice to the processed block
+//   3. Save latest head info
 func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.SignedBeaconBlock, blockRoot [32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlock")
 	defer span.End()
 	receivedTime := time.Now()
-	blockCopy, err := block.Copy()
-	if err != nil {
-		return err
-	}
+	blockCopy := block.Copy()

 	// Apply state transition on the new block.
 	if err := s.onBlock(ctx, blockCopy, blockRoot); err != nil {
@@ -97,10 +94,7 @@ func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []interfaces.Sig
 	}

 	for i, b := range blocks {
-		blockCopy, err := b.Copy()
-		if err != nil {
-			return err
-		}
+		blockCopy := b.Copy()
 		// Send notification of the processed block to the state feed.
 		s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 			Type: statefeed.BlockProcessed,
@@ -128,7 +122,7 @@ func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []interfaces.Sig
 		// log.Fatalf will prevent defer from being called
 		span.End()
 		// Exit run time if the node failed to verify weak subjectivity checkpoint.
-		log.WithError(err).Fatal("Could not verify weak subjectivity checkpoint")
+		log.Fatalf("Could not verify weak subjectivity checkpoint: %v", err)
 	}

 	return nil
@@ -145,6 +139,16 @@ func (s *Service) ReceiveAttesterSlashing(ctx context.Context, slashing *ethpb.A
 }

 func (s *Service) handlePostBlockOperations(b interfaces.BeaconBlock) error {
+	// Delete the processed block attestations from attestation pool.
+	if err := s.deletePoolAtts(b.Body().Attestations()); err != nil {
+		return err
+	}
+
+	// Add block attestations to the fork choice pool to compute head.
+	if err := s.cfg.AttPool.SaveBlockAttestations(b.Body().Attestations()); err != nil {
+		log.Errorf("Could not save block attestations for fork choice: %v", err)
+		return nil
+	}
 	// Mark block exits as seen so we don't include same ones in future blocks.
 	for _, e := range b.Body().VoluntaryExits() {
 		s.cfg.ExitPool.MarkIncluded(e)
--- a/beacon-chain/blockchain/receive_block_test.go
+++ b/beacon-chain/blockchain/receive_block_test.go
@@ -6,21 +6,21 @@ import (
 	"testing"
 	"time"

-	blockchainTesting "github.com/prysmaticlabs/prysm/v3/beacon-chain/blockchain/testing"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/attestations"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/voluntaryexits"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	blockchainTesting "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/voluntaryexits"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )

@@ -33,7 +33,7 @@ func TestService_ReceiveBlock(t *testing.T) {
 		assert.NoError(t, err)
 		return blk
 	}
-	//params.SetupTestConfigCleanupWithLock(t)
+	params.SetupTestConfigCleanup(t)
 	bc := params.BeaconConfig().Copy()
 	bc.ShardCommitteePeriod = 0 // Required for voluntary exits test in reasonable time.
 	params.OverrideBeaconConfig(bc)
@@ -76,9 +76,9 @@ func TestService_ReceiveBlock(t *testing.T) {
 				),
 			},
 			check: func(t *testing.T, s *Service) {
-				if baCount := len(s.cfg.AttPool.BlockAttestations()); baCount != 0 {
+				if baCount := len(s.cfg.AttPool.BlockAttestations()); baCount != 2 {
 					t.Errorf("Did not get the correct number of block attestations saved to the pool. "+
-						"Got %d but wanted %d", baCount, 0)
+						"Got %d but wanted %d", baCount, 2)
 				}
 			},
 		},
@@ -119,32 +119,27 @@ func TestService_ReceiveBlock(t *testing.T) {
 		},
 	}

-	wg := new(sync.WaitGroup)
 	for _, tt := range tests {
-		wg.Add(1)
 		t.Run(tt.name, func(t *testing.T) {
 			beaconDB := testDB.SetupDB(t)
 			genesisBlockRoot := bytesutil.ToBytes32(nil)
 			require.NoError(t, beaconDB.SaveState(ctx, genesis, genesisBlockRoot))

-			fc := doublylinkedtree.New()
 			opts := []Option{
 				WithDatabase(beaconDB),
-				WithForkChoiceStore(fc),
+				WithForkChoiceStore(protoarray.New()),
 				WithAttestationPool(attestations.NewPool()),
 				WithExitPool(voluntaryexits.NewPool()),
 				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
-				WithStateGen(stategen.New(beaconDB, fc)),
+				WithStateGen(stategen.New(beaconDB)),
 				WithFinalizedStateAtStartUp(genesis),
 			}
 			s, err := NewService(ctx, opts...)
 			require.NoError(t, err)
-			// Initialize it here.
-			_ = s.cfg.StateNotifier.StateFeed()
 			require.NoError(t, s.saveGenesisData(ctx, genesis))
 			root, err := tt.args.block.Block.HashTreeRoot()
 			require.NoError(t, err)
-			wsb, err := blocks.NewSignedBeaconBlock(tt.args.block)
+			wsb, err := wrapper.WrappedSignedBeaconBlock(tt.args.block)
 			require.NoError(t, err)
 			err = s.ReceiveBlock(ctx, wsb, root)
 			if tt.wantedErr != "" {
@@ -153,10 +148,8 @@ func TestService_ReceiveBlock(t *testing.T) {
 				assert.NoError(t, err)
 				tt.check(t, s)
 			}
-			wg.Done()
 		})
 	}
-	wg.Wait()
 }

 func TestService_ReceiveBlockUpdateHead(t *testing.T) {
@@ -167,27 +160,24 @@ func TestService_ReceiveBlockUpdateHead(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	genesisBlockRoot := bytesutil.ToBytes32(nil)
 	require.NoError(t, beaconDB.SaveState(ctx, genesis, genesisBlockRoot))
-	fc := doublylinkedtree.New()
 	opts := []Option{
 		WithDatabase(beaconDB),
-		WithForkChoiceStore(fc),
+		WithForkChoiceStore(protoarray.New()),
 		WithAttestationPool(attestations.NewPool()),
 		WithExitPool(voluntaryexits.NewPool()),
 		WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
-		WithStateGen(stategen.New(beaconDB, fc)),
+		WithStateGen(stategen.New(beaconDB)),
 	}

 	s, err := NewService(ctx, opts...)
 	require.NoError(t, err)
-	// Initialize it here.
-	_ = s.cfg.StateNotifier.StateFeed()
 	require.NoError(t, s.saveGenesisData(ctx, genesis))
 	root, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
 	wg := sync.WaitGroup{}
 	wg.Add(1)
 	go func() {
-		wsb, err := blocks.NewSignedBeaconBlock(b)
+		wsb, err := wrapper.WrappedSignedBeaconBlock(b)
 		require.NoError(t, err)
 		require.NoError(t, s.ReceiveBlock(ctx, wsb, root))
 		wg.Done()
@@ -244,13 +234,12 @@ func TestService_ReceiveBlockBatch(t *testing.T) {

 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			fc := doublylinkedtree.New()
 			beaconDB := testDB.SetupDB(t)
 			opts := []Option{
 				WithDatabase(beaconDB),
-				WithForkChoiceStore(fc),
+				WithForkChoiceStore(protoarray.New()),
 				WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}),
-				WithStateGen(stategen.New(beaconDB, fc)),
+				WithStateGen(stategen.New(beaconDB)),
 			}
 			s, err := NewService(ctx, opts...)
 			require.NoError(t, err)
@@ -258,7 +247,7 @@ func TestService_ReceiveBlockBatch(t *testing.T) {
 			require.NoError(t, err)
 			root, err := tt.args.block.Block.HashTreeRoot()
 			require.NoError(t, err)
-			wsb, err := blocks.NewSignedBeaconBlock(tt.args.block)
+			wsb, err := wrapper.WrappedSignedBeaconBlock(tt.args.block)
 			require.NoError(t, err)
 			blks := []interfaces.SignedBeaconBlock{wsb}
 			roots := [][32]byte{root}
@@ -282,7 +271,7 @@ func TestService_HasBlock(t *testing.T) {
 	if s.HasBlock(context.Background(), r) {
 		t.Error("Should not have block")
 	}
-	wsb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	wsb, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
 	require.NoError(t, s.saveInitSyncBlock(context.Background(), r, wsb))
 	if !s.HasBlock(context.Background(), r) {
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -11,36 +11,42 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/async/event"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache/depositcache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/execution"
-	f "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/attestations"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/blstoexec"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/slashings"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/voluntaryexits"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/p2p"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/config/features"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	prysmTime "github.com/prysmaticlabs/prysm/v3/time"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/async/event"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db"
+	f "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/slashings"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/voluntaryexits"
+	"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/config/features"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )

+// headSyncMinEpochsAfterCheckpoint defines how many epochs should elapse after known finalization
+// checkpoint for head sync to be triggered.
+const headSyncMinEpochsAfterCheckpoint = 128
+
 // Service represents a service that handles the internal
 // logic of managing the full PoS beacon chain.
 type Service struct {
@@ -64,14 +70,13 @@ type Service struct {
 // config options for the service.
 type config struct {
 	BeaconBlockBuf          int
-	ChainStartFetcher       execution.ChainStartFetcher
+	ChainStartFetcher       powchain.ChainStartFetcher
 	BeaconDB                db.HeadAccessDatabase
 	DepositCache            *depositcache.DepositCache
 	ProposerSlotIndexCache  *cache.ProposerPayloadIDsCache
 	AttPool                 attestations.Pool
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
-	BLSToExecPool           blstoexec.PoolManager
 	P2p                     p2p.Broadcaster
 	MaxRoutines             int
 	StateNotifier           statefeed.Notifier
@@ -80,9 +85,9 @@ type config struct {
 	StateGen                *stategen.State
 	SlasherAttestationsFeed *event.Feed
 	WeakSubjectivityCheckpt *ethpb.Checkpoint
-	BlockFetcher            execution.POWBlockFetcher
+	BlockFetcher            powchain.POWBlockFetcher
 	FinalizedStateAtStartUp state.BeaconState
-	ExecutionEngineCaller   execution.EngineCaller
+	ExecutionEngineCaller   powchain.EngineCaller
 }

 // NewService instantiates a new block service instance that will
@@ -125,7 +130,7 @@ func (s *Service) Start() {
 			log.Fatal(err)
 		}
 	} else {
-		if err := s.startFromExecutionChain(); err != nil {
+		if err := s.startFromPOWChain(); err != nil {
 			log.Fatal(err)
 		}
 	}
@@ -156,15 +161,6 @@ func (s *Service) Stop() error {
 // Status always returns nil unless there is an error condition that causes
 // this service to be unhealthy.
 func (s *Service) Status() error {
-	optimistic, err := s.IsOptimistic(s.ctx)
-	if err != nil {
-		return errors.Wrap(err, "failed to check if service is optimistic")
-	}
-	if optimistic {
-		return errors.New("service is optimistic, and only limited service functionality is provided " +
-			"please check if execution layer is fully synced")
-	}
-
 	if s.originBlockRoot == params.BeaconConfig().ZeroHash {
 		return errors.New("genesis state has not been created")
 	}
@@ -206,33 +202,39 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 		return errNilFinalizedCheckpoint
 	}

+	var forkChoicer f.ForkChoicer
 	fRoot := s.ensureRootNotZeros(bytesutil.ToBytes32(finalized.Root))
-	if err := s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: justified.Epoch,
+	if features.Get().EnableForkChoiceDoublyLinkedTree {
+		forkChoicer = doublylinkedtree.New()
+	} else {
+		forkChoicer = protoarray.New()
+	}
+	s.cfg.ForkChoiceStore = forkChoicer
+	if err := forkChoicer.UpdateJustifiedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: justified.Epoch,
 		Root: bytesutil.ToBytes32(justified.Root)}); err != nil {
 		return errors.Wrap(err, "could not update forkchoice's justified checkpoint")
 	}
-	if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: finalized.Epoch,
+	if err := forkChoicer.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: finalized.Epoch,
 		Root: bytesutil.ToBytes32(finalized.Root)}); err != nil {
 		return errors.Wrap(err, "could not update forkchoice's finalized checkpoint")
 	}
-	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(s.genesisTime.Unix()))
+	forkChoicer.SetGenesisTime(uint64(s.genesisTime.Unix()))

 	st, err := s.cfg.StateGen.StateByRoot(s.ctx, fRoot)
 	if err != nil {
 		return errors.Wrap(err, "could not get finalized checkpoint state")
 	}
-	if err := s.cfg.ForkChoiceStore.InsertNode(s.ctx, st, fRoot); err != nil {
+	if err := forkChoicer.InsertNode(s.ctx, st, fRoot); err != nil {
 		return errors.Wrap(err, "could not insert finalized block to forkchoice")
 	}
-	if !features.Get().EnableStartOptimistic {
-		lastValidatedCheckpoint, err := s.cfg.BeaconDB.LastValidatedCheckpoint(s.ctx)
-		if err != nil {
-			return errors.Wrap(err, "could not get last validated checkpoint")
-		}
-		if bytes.Equal(finalized.Root, lastValidatedCheckpoint.Root) {
-			if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(s.ctx, fRoot); err != nil {
-				return errors.Wrap(err, "could not set finalized block as validated")
-			}
+
+	lastValidatedCheckpoint, err := s.cfg.BeaconDB.LastValidatedCheckpoint(s.ctx)
+	if err != nil {
+		return errors.Wrap(err, "could not get last validated checkpoint")
+	}
+	if bytes.Equal(finalized.Root, lastValidatedCheckpoint.Root) {
+		if err := forkChoicer.SetOptimisticToValid(s.ctx, fRoot); err != nil {
+			return errors.Wrap(err, "could not set finalized block as validated")
 		}
 	}
 	// not attempting to save initial sync blocks here, because there shouldn't be any until
@@ -269,7 +271,7 @@ func (s *Service) originRootFromSavedState(ctx context.Context) ([32]byte, error
 	if err != nil {
 		return originRoot, errors.Wrap(err, "could not get genesis block from db")
 	}
-	if err := blocks.BeaconBlockIsNil(genesisBlock); err != nil {
+	if err := wrapper.BeaconBlockIsNil(genesisBlock); err != nil {
 		return originRoot, err
 	}
 	genesisBlkRoot, err := genesisBlock.Block().HashTreeRoot()
@@ -300,6 +302,41 @@ func (s *Service) initializeHeadFromDB(ctx context.Context) error {
 		return errors.Wrap(err, "could not get finalized state from db")
 	}

+	if flags.Get().HeadSync {
+		headBlock, err := s.cfg.BeaconDB.HeadBlock(ctx)
+		if err != nil {
+			return errors.Wrap(err, "could not retrieve head block")
+		}
+		headEpoch := slots.ToEpoch(headBlock.Block().Slot())
+		var epochsSinceFinality types.Epoch
+		if headEpoch > finalized.Epoch {
+			epochsSinceFinality = headEpoch - finalized.Epoch
+		}
+		// Head sync when node is far enough beyond known finalized epoch,
+		// this becomes really useful during long period of non-finality.
+		if epochsSinceFinality >= headSyncMinEpochsAfterCheckpoint {
+			headRoot, err := headBlock.Block().HashTreeRoot()
+			if err != nil {
+				return errors.Wrap(err, "could not hash head block")
+			}
+			finalizedState, err := s.cfg.StateGen.Resume(ctx, s.cfg.FinalizedStateAtStartUp)
+			if err != nil {
+				return errors.Wrap(err, "could not get finalized state from db")
+			}
+			log.Infof("Regenerating state from the last checkpoint at slot %d to current head slot of %d."+
+				"This process may take a while, please wait.", finalizedState.Slot(), headBlock.Block().Slot())
+			headState, err := s.cfg.StateGen.StateByRoot(ctx, headRoot)
+			if err != nil {
+				return errors.Wrap(err, "could not retrieve head state")
+			}
+			s.setHead(headRoot, headBlock, headState)
+			return nil
+		} else {
+			log.Warnf("Finalized checkpoint at slot %d is too close to the current head slot, "+
+				"resetting head from the checkpoint ('--%s' flag is ignored).",
+				finalizedState.Slot(), flags.HeadSync.Name)
+		}
+	}
 	if finalizedState == nil || finalizedState.IsNil() {
 		return errors.New("finalized state can't be nil")
 	}
@@ -308,17 +345,15 @@ func (s *Service) initializeHeadFromDB(ctx context.Context) error {
 	if err != nil {
 		return errors.Wrap(err, "could not get finalized block")
 	}
-	if err := s.setHead(finalizedRoot, finalizedBlock, finalizedState); err != nil {
-		return errors.Wrap(err, "could not set head")
-	}
+	s.setHead(finalizedRoot, finalizedBlock, finalizedState)

 	return nil
 }

-func (s *Service) startFromExecutionChain() error {
+func (s *Service) startFromPOWChain() error {
 	log.Info("Waiting to reach the validator deposit threshold to start the beacon chain...")
 	if s.cfg.ChainStartFetcher == nil {
-		return errors.New("not configured execution chain")
+		return errors.New("not configured web3Service for POW chain")
 	}
 	go func() {
 		stateChannel := make(chan *feed.Event, 1)
@@ -334,7 +369,7 @@ func (s *Service) startFromExecutionChain() error {
 						return
 					}
 					log.WithField("starttime", data.StartTime).Debug("Received chain start event")
-					s.onExecutionChainStart(s.ctx, data.StartTime)
+					s.onPowchainStart(s.ctx, data.StartTime)
 					return
 				}
 			case <-s.ctx.Done():
@@ -350,18 +385,18 @@ func (s *Service) startFromExecutionChain() error {
 	return nil
 }

-// onExecutionChainStart initializes a series of deposits from the ChainStart deposits in the eth1
+// onPowchainStart initializes a series of deposits from the ChainStart deposits in the eth1
 // deposit contract, initializes the beacon chain's state, and kicks off the beacon chain.
-func (s *Service) onExecutionChainStart(ctx context.Context, genesisTime time.Time) {
+func (s *Service) onPowchainStart(ctx context.Context, genesisTime time.Time) {
 	preGenesisState := s.cfg.ChainStartFetcher.PreGenesisState()
 	initializedState, err := s.initializeBeaconChain(ctx, genesisTime, preGenesisState, s.cfg.ChainStartFetcher.ChainStartEth1Data())
 	if err != nil {
-		log.WithError(err).Fatal("Could not initialize beacon chain")
+		log.Fatalf("Could not initialize beacon chain: %v", err)
 	}
 	// We start a counter to genesis, if needed.
 	gRoot, err := initializedState.HashTreeRoot(s.ctx)
 	if err != nil {
-		log.WithError(err).Fatal("Could not hash tree root genesis state")
+		log.Fatalf("Could not hash tree root genesis state: %v", err)
 	}
 	go slots.CountdownToGenesis(ctx, genesisTime, uint64(initializedState.NumValidators()), gRoot)

@@ -434,7 +469,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon
 	s.cfg.StateGen.SaveFinalizedState(0 /*slot*/, genesisBlkRoot, genesisState)

 	if err := s.cfg.ForkChoiceStore.InsertNode(ctx, genesisState, genesisBlkRoot); err != nil {
-		log.WithError(err).Fatal("Could not process genesis block for fork choice")
+		log.Fatalf("Could not process genesis block for fork choice: %v", err)
 	}
 	s.cfg.ForkChoiceStore.SetOriginRoot(genesisBlkRoot)
 	// Set genesis as fully validated
@@ -443,9 +478,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon
 	}
 	s.cfg.ForkChoiceStore.SetGenesisTime(uint64(s.genesisTime.Unix()))

-	if err := s.setHead(genesisBlkRoot, genesisBlk, genesisState); err != nil {
-		log.WithError(err).Fatal("Could not set head")
-	}
+	s.setHead(genesisBlkRoot, genesisBlk, genesisState)
 	return nil
 }

@@ -469,11 +502,11 @@ func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db d

 	gState, err := db.GenesisState(ctx)
 	if err != nil {
-		log.WithError(err).Fatal("Could not retrieve genesis state")
+		log.Fatalf("Could not retrieve genesis state: %v", err)
 	}
 	gRoot, err := gState.HashTreeRoot(ctx)
 	if err != nil {
-		log.WithError(err).Fatal("Could not hash tree root genesis state")
+		log.Fatalf("Could not hash tree root genesis state: %v", err)
 	}
 	go slots.CountdownToGenesis(ctx, genesisTime, uint64(gState.NumValidators()), gRoot)
 }
--- a/beacon-chain/blockchain/service_norace_test.go
+++ b/beacon-chain/blockchain/service_norace_test.go
@@ -5,10 +5,10 @@ import (
 	"io"
 	"testing"

-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 	"github.com/sirupsen/logrus"
 )

@@ -22,7 +22,7 @@ func TestChainService_SaveHead_DataRace(t *testing.T) {
 	s := &Service{
 		cfg: &config{BeaconDB: beaconDB},
 	}
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
 	st, _ := util.DeterministicGenesisState(t, 1)
 	require.NoError(t, err)
 	go func() {
--- a/beacon-chain/blockchain/service_test.go
+++ b/beacon-chain/blockchain/service_test.go
@@ -8,34 +8,35 @@ import (
 	"time"

 	"github.com/ethereum/go-ethereum/common"
-	"github.com/prysmaticlabs/prysm/v3/async/event"
-	mock "github.com/prysmaticlabs/prysm/v3/beacon-chain/blockchain/testing"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/cache/depositcache"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/transition"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/execution"
-	mockExecution "github.com/prysmaticlabs/prysm/v3/beacon-chain/execution/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/operations/attestations"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/p2p"
-	state_native "github.com/prysmaticlabs/prysm/v3/beacon-chain/state/state-native"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
-	"github.com/prysmaticlabs/prysm/v3/config/features"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	consensusblocks "github.com/prysmaticlabs/prysm/v3/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v3/container/trie"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/assert"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/async/event"
+	mock "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
+	"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
+	mockPOW "github.com/prysmaticlabs/prysm/beacon-chain/powchain/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
+	"github.com/prysmaticlabs/prysm/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/container/trie"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"google.golang.org/protobuf/proto"
 )
@@ -75,19 +76,19 @@ var _ p2p.Broadcaster = (*mockBroadcaster)(nil)

 func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 	ctx := context.Background()
-	var web3Service *execution.Service
+	var web3Service *powchain.Service
 	var err error
-	srv, endpoint, err := mockExecution.SetupRPCServer()
+	srv, endpoint, err := mockPOW.SetupRPCServer()
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		srv.Stop()
 	})
 	bState, _ := util.DeterministicGenesisState(t, 10)
-	pbState, err := state_native.ProtobufBeaconStatePhase0(bState.ToProtoUnsafe())
+	pbState, err := v1.ProtobufBeaconState(bState.InnerStateUnsafe())
 	require.NoError(t, err)
 	mockTrie, err := trie.NewTrie(0)
 	require.NoError(t, err)
-	err = beaconDB.SaveExecutionChainData(ctx, &ethpb.ETH1ChainData{
+	err = beaconDB.SavePowchainData(ctx, &ethpb.ETH1ChainData{
 		BeaconState: pbState,
 		Trie:        mockTrie.ToProto(),
 		CurrentEth1Data: &ethpb.LatestETH1Data{
@@ -103,11 +104,11 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		DepositContainers: []*ethpb.DepositContainer{},
 	})
 	require.NoError(t, err)
-	web3Service, err = execution.NewService(
+	web3Service, err = powchain.NewService(
 		ctx,
-		execution.WithDatabase(beaconDB),
-		execution.WithHttpEndpoint(endpoint),
-		execution.WithDepositContractAddress(common.Address{}),
+		powchain.WithDatabase(beaconDB),
+		powchain.WithHttpEndpoints([]string{endpoint}),
+		powchain.WithDepositContractAddress(common.Address{}),
 	)
 	require.NoError(t, err, "Unable to set up web3 service")

@@ -117,8 +118,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 	depositCache, err := depositcache.New()
 	require.NoError(t, err)

-	fc := doublylinkedtree.New()
-	stateGen := stategen.New(beaconDB, fc)
+	stateGen := stategen.New(beaconDB)
 	// Safe a state in stategen to purposes of testing a service stop / shutdown.
 	require.NoError(t, stateGen.SaveState(ctx, bytesutil.ToBytes32(bState.FinalizedCheckpoint().Root), bState))

@@ -129,7 +129,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		WithAttestationPool(attestations.NewPool()),
 		WithP2PBroadcaster(&mockBroadcaster{}),
 		WithStateNotifier(&mockBeaconNode{}),
-		WithForkChoiceStore(fc),
+		WithForkChoiceStore(protoarray.New()),
 		WithAttestationService(attService),
 		WithStateGen(stateGen),
 	}
@@ -306,26 +306,17 @@ func TestChainService_InitializeChainInfo(t *testing.T) {
 	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
 	attSrv, err := attestations.NewService(ctx, &attestations.Config{})
 	require.NoError(t, err)
-	fc := doublylinkedtree.New()
-	stateGen := stategen.New(beaconDB, fc)
-	c, err := NewService(ctx,
-		WithForkChoiceStore(fc),
-		WithDatabase(beaconDB),
-		WithStateGen(stateGen),
-		WithAttestationService(attSrv),
-		WithStateNotifier(&mock.MockStateNotifier{}),
-		WithFinalizedStateAtStartUp(headState))
+	stateGen := stategen.New(beaconDB)
+	c, err := NewService(ctx, WithDatabase(beaconDB), WithStateGen(stateGen), WithAttestationService(attSrv), WithStateNotifier(&mock.MockStateNotifier{}), WithFinalizedStateAtStartUp(headState))
 	require.NoError(t, err)
 	require.NoError(t, stateGen.SaveState(ctx, headRoot, headState))
 	require.NoError(t, c.StartFromSavedState(headState))
 	headBlk, err := c.HeadBlock(ctx)
 	require.NoError(t, err)
-	pb, err := headBlk.Proto()
-	require.NoError(t, err)
-	assert.DeepEqual(t, headBlock, pb, "Head block incorrect")
+	assert.DeepEqual(t, headBlock, headBlk.Proto(), "Head block incorrect")
 	s, err := c.HeadState(ctx)
 	require.NoError(t, err)
-	assert.DeepSSZEqual(t, headState.ToProtoUnsafe(), s.ToProtoUnsafe(), "Head state incorrect")
+	assert.DeepSSZEqual(t, headState.InnerStateUnsafe(), s.InnerStateUnsafe(), "Head state incorrect")
 	assert.Equal(t, c.HeadSlot(), headBlock.Block.Slot, "Head slot incorrect")
 	r, err := c.HeadRoot(context.Background())
 	require.NoError(t, err)
@@ -366,33 +357,107 @@ func TestChainService_InitializeChainInfo_SetHeadAtGenesis(t *testing.T) {
 	}
 	require.NoError(t, beaconDB.SaveStateSummary(ctx, ss))
 	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Root: headRoot[:], Epoch: slots.ToEpoch(finalizedSlot)}))
-	fc := doublylinkedtree.New()
-	stateGen := stategen.New(beaconDB, fc)
-	c, err := NewService(ctx,
-		WithForkChoiceStore(fc),
-		WithDatabase(beaconDB),
-		WithStateGen(stateGen),
-		WithAttestationService(attSrv),
-		WithStateNotifier(&mock.MockStateNotifier{}),
-		WithFinalizedStateAtStartUp(headState))
+	stateGen := stategen.New(beaconDB)
+	c, err := NewService(ctx, WithDatabase(beaconDB), WithStateGen(stateGen), WithAttestationService(attSrv), WithStateNotifier(&mock.MockStateNotifier{}), WithFinalizedStateAtStartUp(headState))
 	require.NoError(t, err)

 	require.NoError(t, c.StartFromSavedState(headState))
 	s, err := c.HeadState(ctx)
 	require.NoError(t, err)
-	assert.DeepSSZEqual(t, headState.ToProtoUnsafe(), s.ToProtoUnsafe(), "Head state incorrect")
+	assert.DeepSSZEqual(t, headState.InnerStateUnsafe(), s.InnerStateUnsafe(), "Head state incorrect")
 	assert.Equal(t, genesisRoot, c.originBlockRoot, "Genesis block root incorrect")
-	pb, err := c.head.block.Proto()
+	assert.DeepEqual(t, headBlock, c.head.block.Proto())
+}
+
+func TestChainService_InitializeChainInfo_HeadSync(t *testing.T) {
+	resetFlags := flags.Get()
+	flags.Init(&flags.GlobalFlags{
+		HeadSync: true,
+	})
+	defer func() {
+		flags.Init(resetFlags)
+	}()
+
+	hook := logTest.NewGlobal()
+	finalizedSlot := params.BeaconConfig().SlotsPerEpoch*2 + 1
+	beaconDB := testDB.SetupDB(t)
+	ctx := context.Background()
+
+	genesisBlock := util.NewBeaconBlock()
+	genesisRoot, err := genesisBlock.Block.HashTreeRoot()
 	require.NoError(t, err)
-	assert.DeepEqual(t, headBlock, pb)
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, genesisRoot))
+	util.SaveBlock(t, ctx, beaconDB, genesisBlock)
+
+	finalizedBlock := util.NewBeaconBlock()
+	finalizedBlock.Block.Slot = finalizedSlot
+	finalizedBlock.Block.ParentRoot = genesisRoot[:]
+	finalizedRoot, err := finalizedBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, ctx, beaconDB, finalizedBlock)
+
+	// Set head slot close to the finalization point, no head sync is triggered.
+	headBlock := util.NewBeaconBlock()
+	headBlock.Block.Slot = finalizedSlot + params.BeaconConfig().SlotsPerEpoch*5
+	headBlock.Block.ParentRoot = finalizedRoot[:]
+	headRoot, err := headBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, ctx, beaconDB, headBlock)
+
+	headState, err := util.NewBeaconState()
+	require.NoError(t, err)
+	require.NoError(t, headState.SetSlot(headBlock.Block.Slot))
+	require.NoError(t, headState.SetGenesisValidatorsRoot(params.BeaconConfig().ZeroHash[:]))
+	require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
+	require.NoError(t, beaconDB.SaveState(ctx, headState, finalizedRoot))
+	require.NoError(t, beaconDB.SaveHeadBlockRoot(ctx, headRoot))
+	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{
+		Epoch: slots.ToEpoch(finalizedBlock.Block.Slot),
+		Root:  finalizedRoot[:],
+	}))
+
+	attSrv, err := attestations.NewService(ctx, &attestations.Config{})
+	require.NoError(t, err)
+	stateGen := stategen.New(beaconDB)
+	c, err := NewService(ctx, WithDatabase(beaconDB), WithStateGen(stateGen), WithAttestationService(attSrv), WithStateNotifier(&mock.MockStateNotifier{}), WithFinalizedStateAtStartUp(headState))
+	require.NoError(t, err)
+	require.NoError(t, c.StartFromSavedState(headState))
+	s, err := c.HeadState(ctx)
+	require.NoError(t, err)
+	assert.DeepSSZEqual(t, headState.InnerStateUnsafe(), s.InnerStateUnsafe(), "Head state incorrect")
+	assert.Equal(t, genesisRoot, c.originBlockRoot, "Genesis block root incorrect")
+	// Since head sync is not triggered, chain is initialized to the last finalization checkpoint.
+	assert.DeepEqual(t, finalizedBlock, c.head.block.Proto())
+	assert.LogsContain(t, hook, "resetting head from the checkpoint ('--head-sync' flag is ignored)")
+	assert.LogsDoNotContain(t, hook, "Regenerating state from the last checkpoint at slot")
+
+	// Set head slot far beyond the finalization point, head sync should be triggered.
+	headBlock = util.NewBeaconBlock()
+	headBlock.Block.Slot = finalizedSlot + params.BeaconConfig().SlotsPerEpoch*headSyncMinEpochsAfterCheckpoint
+	headBlock.Block.ParentRoot = finalizedRoot[:]
+	headRoot, err = headBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, ctx, beaconDB, headBlock)
+	require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
+	require.NoError(t, beaconDB.SaveHeadBlockRoot(ctx, headRoot))
+
+	hook.Reset()
+	require.NoError(t, c.initializeHeadFromDB(ctx))
+	s, err = c.HeadState(ctx)
+	require.NoError(t, err)
+	assert.DeepSSZEqual(t, headState.InnerStateUnsafe(), s.InnerStateUnsafe(), "Head state incorrect")
+	assert.Equal(t, genesisRoot, c.originBlockRoot, "Genesis block root incorrect")
+	// Head slot is far beyond the latest finalized checkpoint, head sync is triggered.
+	assert.DeepEqual(t, headBlock, c.head.block.Proto())
+	assert.LogsContain(t, hook, "Regenerating state from the last checkpoint at slot 225")
+	assert.LogsDoNotContain(t, hook, "resetting head from the checkpoint ('--head-sync' flag is ignored)")
 }

 func TestChainService_SaveHeadNoDB(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	ctx := context.Background()
-	fc := doublylinkedtree.New()
 	s := &Service{
-		cfg: &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, fc), ForkChoiceStore: fc},
+		cfg: &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB), ForkChoiceStore: protoarray.New()},
 	}
 	blk := util.NewBeaconBlock()
 	blk.Block.Slot = 1
@@ -401,7 +466,7 @@ func TestChainService_SaveHeadNoDB(t *testing.T) {
 	newState, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, s.cfg.StateGen.SaveState(ctx, r, newState))
-	wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 	require.NoError(t, s.saveHeadNoDB(ctx, wsb, r, newState))

@@ -412,6 +477,25 @@ func TestChainService_SaveHeadNoDB(t *testing.T) {
 	}
 }

+func TestHasBlock_ForkChoiceAndDB_ProtoArray(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	s := &Service{
+		cfg: &config{ForkChoiceStore: protoarray.New(), BeaconDB: beaconDB},
+	}
+	b := util.NewBeaconBlock()
+	r, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	beaconState, err := util.NewBeaconState()
+	require.NoError(t, err)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
+	require.NoError(t, err)
+	require.NoError(t, s.insertBlockAndAttestationsToForkChoiceStore(ctx, wsb.Block(), r, beaconState))
+
+	assert.Equal(t, false, s.hasBlock(ctx, [32]byte{}), "Should not have block")
+	assert.Equal(t, true, s.hasBlock(ctx, r), "Should have block")
+}
+
 func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
@@ -423,9 +507,9 @@ func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
 	require.NoError(t, err)
 	beaconState, err := util.NewBeaconState()
 	require.NoError(t, err)
-	wsb, err := consensusblocks.NewSignedBeaconBlock(b)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
 	require.NoError(t, err)
-	require.NoError(t, s.insertBlockToForkchoiceStore(ctx, wsb.Block(), r, beaconState))
+	require.NoError(t, s.insertBlockAndAttestationsToForkChoiceStore(ctx, wsb.Block(), r, beaconState))

 	assert.Equal(t, false, s.hasBlock(ctx, [32]byte{}), "Should not have block")
 	assert.Equal(t, true, s.hasBlock(ctx, r), "Should have block")
@@ -435,7 +519,7 @@ func TestServiceStop_SaveCachedBlocks(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	beaconDB := testDB.SetupDB(t)
 	s := &Service{
-		cfg:            &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB, doublylinkedtree.New())},
+		cfg:            &config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB)},
 		ctx:            ctx,
 		cancel:         cancel,
 		initSyncBlocks: make(map[[32]byte]interfaces.SignedBeaconBlock),
@@ -443,7 +527,7 @@ func TestServiceStop_SaveCachedBlocks(t *testing.T) {
 	bb := util.NewBeaconBlock()
 	r, err := bb.Block.HashTreeRoot()
 	require.NoError(t, err)
-	wsb, err := consensusblocks.NewSignedBeaconBlock(bb)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(bb)
 	require.NoError(t, err)
 	require.NoError(t, s.saveInitSyncBlock(ctx, r, wsb))
 	require.NoError(t, s.Stop())
@@ -456,7 +540,7 @@ func TestProcessChainStartTime_ReceivedFeed(t *testing.T) {
 	stateChannel := make(chan *feed.Event, 1)
 	stateSub := service.cfg.StateNotifier.StateFeed().Subscribe(stateChannel)
 	defer stateSub.Unsubscribe()
-	service.onExecutionChainStart(context.Background(), time.Now())
+	service.onPowchainStart(context.Background(), time.Now())

 	stateEvent := <-stateChannel
 	require.Equal(t, int(stateEvent.Type), statefeed.Initialized)
@@ -471,7 +555,7 @@ func BenchmarkHasBlockDB(b *testing.B) {
 		cfg: &config{BeaconDB: beaconDB},
 	}
 	blk := util.NewBeaconBlock()
-	wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(b, err)
 	require.NoError(b, s.cfg.BeaconDB.SaveBlock(ctx, wsb))
 	r, err := blk.Block.HashTreeRoot()
@@ -483,6 +567,27 @@ func BenchmarkHasBlockDB(b *testing.B) {
 	}
 }

+func BenchmarkHasBlockForkChoiceStore_ProtoArray(b *testing.B) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(b)
+	s := &Service{
+		cfg: &config{ForkChoiceStore: protoarray.New(), BeaconDB: beaconDB},
+	}
+	blk := &ethpb.SignedBeaconBlock{Block: &ethpb.BeaconBlock{Body: &ethpb.BeaconBlockBody{}}}
+	r, err := blk.Block.HashTreeRoot()
+	require.NoError(b, err)
+	bs := &ethpb.BeaconState{FinalizedCheckpoint: &ethpb.Checkpoint{Root: make([]byte, 32)}, CurrentJustifiedCheckpoint: &ethpb.Checkpoint{Root: make([]byte, 32)}}
+	beaconState, err := v1.InitializeFromProto(bs)
+	require.NoError(b, err)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
+	require.NoError(b, err)
+	require.NoError(b, s.insertBlockAndAttestationsToForkChoiceStore(ctx, wsb.Block(), r, beaconState))
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		require.Equal(b, true, s.cfg.ForkChoiceStore.HasNode(r), "Block is not in fork choice store")
+	}
+}
 func BenchmarkHasBlockForkChoiceStore_DoublyLinkedTree(b *testing.B) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(b)
@@ -493,63 +598,14 @@ func BenchmarkHasBlockForkChoiceStore_DoublyLinkedTree(b *testing.B) {
 	r, err := blk.Block.HashTreeRoot()
 	require.NoError(b, err)
 	bs := &ethpb.BeaconState{FinalizedCheckpoint: &ethpb.Checkpoint{Root: make([]byte, 32)}, CurrentJustifiedCheckpoint: &ethpb.Checkpoint{Root: make([]byte, 32)}}
-	beaconState, err := state_native.InitializeFromProtoPhase0(bs)
+	beaconState, err := v1.InitializeFromProto(bs)
 	require.NoError(b, err)
-	wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(b, err)
-	require.NoError(b, s.insertBlockToForkchoiceStore(ctx, wsb.Block(), r, beaconState))
+	require.NoError(b, s.insertBlockAndAttestationsToForkChoiceStore(ctx, wsb.Block(), r, beaconState))

 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		require.Equal(b, true, s.cfg.ForkChoiceStore.HasNode(r), "Block is not in fork choice store")
 	}
 }
-
-func TestChainService_EverythingOptimistic(t *testing.T) {
-	resetFn := features.InitWithReset(&features.Flags{
-		EnableStartOptimistic: true,
-	})
-	defer resetFn()
-	beaconDB := testDB.SetupDB(t)
-	ctx := context.Background()
-
-	genesis := util.NewBeaconBlock()
-	genesisRoot, err := genesis.Block.HashTreeRoot()
-	require.NoError(t, err)
-	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, genesisRoot))
-	util.SaveBlock(t, ctx, beaconDB, genesis)
-
-	finalizedSlot := params.BeaconConfig().SlotsPerEpoch*2 + 1
-	headBlock := util.NewBeaconBlock()
-	headBlock.Block.Slot = finalizedSlot
-	headBlock.Block.ParentRoot = bytesutil.PadTo(genesisRoot[:], 32)
-	headState, err := util.NewBeaconState()
-	require.NoError(t, err)
-	require.NoError(t, headState.SetSlot(finalizedSlot))
-	require.NoError(t, headState.SetGenesisValidatorsRoot(params.BeaconConfig().ZeroHash[:]))
-	headRoot, err := headBlock.Block.HashTreeRoot()
-	require.NoError(t, err)
-	require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
-	require.NoError(t, beaconDB.SaveState(ctx, headState, genesisRoot))
-	util.SaveBlock(t, ctx, beaconDB, headBlock)
-	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
-	attSrv, err := attestations.NewService(ctx, &attestations.Config{})
-	require.NoError(t, err)
-	fc := doublylinkedtree.New()
-	stateGen := stategen.New(beaconDB, fc)
-	c, err := NewService(ctx,
-		WithForkChoiceStore(fc),
-		WithDatabase(beaconDB),
-		WithStateGen(stateGen),
-		WithAttestationService(attSrv),
-		WithStateNotifier(&mock.MockStateNotifier{}),
-		WithFinalizedStateAtStartUp(headState))
-	require.NoError(t, err)
-	require.NoError(t, stateGen.SaveState(ctx, headRoot, headState))
-	require.NoError(t, beaconDB.SaveLastValidatedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
-	require.NoError(t, c.StartFromSavedState(headState))
-	require.Equal(t, true, c.cfg.ForkChoiceStore.HasNode(headRoot))
-	op, err := c.cfg.ForkChoiceStore.IsOptimistic(headRoot)
-	require.NoError(t, err)
-	require.Equal(t, true, op)
-}
--- a/beacon-chain/blockchain/state_balance_cache.go
+++ b/beacon-chain/blockchain/state_balance_cache.go
@@ -5,10 +5,10 @@ import (
 	"errors"
 	"sync"

-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/time"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
 )

 type stateBalanceCache struct {
--- a/beacon-chain/blockchain/state_balance_cache_test.go
+++ b/beacon-chain/blockchain/state_balance_cache_test.go
@@ -6,13 +6,13 @@ import (
 	"errors"
 	"testing"

-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	state_native "github.com/prysmaticlabs/prysm/v3/beacon-chain/state/state-native"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	v2 "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

 type testStateOpt func(*ethpb.BeaconStateAltair)
@@ -34,7 +34,7 @@ func testStateFixture(opts ...testStateOpt) state.BeaconState {
 	for _, o := range opts {
 		o(a)
 	}
-	s, _ := state_native.InitializeFromProtoUnsafeAltair(a)
+	s, _ := v2.InitializeFromProtoUnsafe(a)
 	return s
 }

--- a/beacon-chain/blockchain/testing/BUILD.bazel
+++ b/beacon-chain/blockchain/testing/BUILD.bazel
@@ -4,7 +4,7 @@ go_library(
    name = "go_default_library",
    testonly = True,
    srcs = ["mock.go"],
-    importpath = "github.com/prysmaticlabs/prysm/v3/beacon-chain/blockchain/testing",
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing",
    visibility = [
        "//beacon-chain:__subpackages__",
        "//testing:__subpackages__",
--- a/beacon-chain/blockchain/testing/mock.go
+++ b/beacon-chain/blockchain/testing/mock.go
@@ -9,22 +9,22 @@ import (
 	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/async/event"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/epoch/precompute"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed"
-	blockfeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/block"
-	opfeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/operation"
-	statefeed "github.com/prysmaticlabs/prysm/v3/beacon-chain/core/feed/state"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/state"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	"github.com/prysmaticlabs/prysm/v3/consensus-types/interfaces"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/async/event"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
+	blockfeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/block"
+	opfeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/operation"
+	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/sirupsen/logrus"
 )

@@ -131,16 +131,13 @@ func (msn *MockStateNotifier) StateFeed() *event.Feed {
 			sub := msn.feed.Subscribe(msn.recvCh)

 			go func() {
-				for {
-					select {
-					case evt := <-msn.recvCh:
-						msn.recvLock.Lock()
-						msn.recv = append(msn.recv, evt)
-						msn.recvLock.Unlock()
-					case <-sub.Err():
-						sub.Unsubscribe()
-						return
-					}
+				select {
+				case evt := <-msn.recvCh:
+					msn.recvLock.Lock()
+					msn.recv = append(msn.recv, evt)
+					msn.recvLock.Unlock()
+				case <-sub.Err():
+					sub.Unsubscribe()
 				}
 			}()
 		}
@@ -174,8 +171,7 @@ func (s *ChainService) ReceiveBlockInitialSync(ctx context.Context, block interf
 	if s.State == nil {
 		return ErrNilState
 	}
-	parentRoot := block.Block().ParentRoot()
-	if !bytes.Equal(s.Root, parentRoot[:]) {
+	if !bytes.Equal(s.Root, block.Block().ParentRoot()) {
 		return errors.Errorf("wanted %#x but got %#x", s.Root, block.Block().ParentRoot())
 	}
 	if err := s.State.SetSlot(block.Block().Slot()); err != nil {
@@ -203,8 +199,7 @@ func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []interfaces.
 		return ErrNilState
 	}
 	for _, b := range blks {
-		parentRoot := b.Block().ParentRoot()
-		if !bytes.Equal(s.Root, parentRoot[:]) {
+		if !bytes.Equal(s.Root, b.Block().ParentRoot()) {
 			return errors.Errorf("wanted %#x but got %#x", s.Root, b.Block().ParentRoot())
 		}
 		if err := s.State.SetSlot(b.Block().Slot()); err != nil {
@@ -235,8 +230,7 @@ func (s *ChainService) ReceiveBlock(ctx context.Context, block interfaces.Signed
 	if s.State == nil {
 		return ErrNilState
 	}
-	parentRoot := block.Block().ParentRoot()
-	if !bytes.Equal(s.Root, parentRoot[:]) {
+	if !bytes.Equal(s.Root, block.Block().ParentRoot()) {
 		return errors.Errorf("wanted %#x but got %#x", s.Root, block.Block().ParentRoot())
 	}
 	if err := s.State.SetSlot(block.Block().Slot()); err != nil {
--- a/beacon-chain/blockchain/weak_subjectivity_checks.go
+++ b/beacon-chain/blockchain/weak_subjectivity_checks.go
@@ -5,12 +5,12 @@ import (
 	"fmt"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db/filters"
-	"github.com/prysmaticlabs/prysm/v3/config/params"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

 type weakSubjectivityDB interface {
@@ -30,7 +30,8 @@ type WeakSubjectivityVerifier struct {
 // NewWeakSubjectivityVerifier validates a checkpoint, and if valid, uses it to initialize a weak subjectivity verifier.
 func NewWeakSubjectivityVerifier(wsc *ethpb.Checkpoint, db weakSubjectivityDB) (*WeakSubjectivityVerifier, error) {
 	if wsc == nil || len(wsc.Root) == 0 || wsc.Epoch == 0 {
-		log.Debug("--weak-subjectivity-checkpoint not provided")
+		log.Info("--weak-subjectivity-checkpoint not provided. Prysm recommends providing a weak subjectivity checkpoint" +
+			"for nodes synced from genesis, or manual verification of block and state roots for checkpoint sync nodes.")
 		return &WeakSubjectivityVerifier{
 			enabled: false,
 		}, nil
--- a/beacon-chain/blockchain/weak_subjectivity_checks_test.go
+++ b/beacon-chain/blockchain/weak_subjectivity_checks_test.go
@@ -5,16 +5,16 @@ import (
 	"testing"

 	"github.com/pkg/errors"
-	testDB "github.com/prysmaticlabs/prysm/v3/beacon-chain/db/testing"
-	doublylinkedtree "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/doubly-linked-tree"
-	forkchoicetypes "github.com/prysmaticlabs/prysm/v3/beacon-chain/forkchoice/types"
-	fieldparams "github.com/prysmaticlabs/prysm/v3/config/fieldparams"
-	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
-	ethpb "github.com/prysmaticlabs/prysm/v3/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v3/testing/require"
-	"github.com/prysmaticlabs/prysm/v3/testing/util"
-	"github.com/prysmaticlabs/prysm/v3/time/slots"
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )

 func TestService_VerifyWeakSubjectivityRoot(t *testing.T) {
@@ -72,7 +72,7 @@ func TestService_VerifyWeakSubjectivityRoot(t *testing.T) {
 			wv, err := NewWeakSubjectivityVerifier(tt.checkpt, beaconDB)
 			require.Equal(t, !tt.disabled, wv.enabled)
 			require.NoError(t, err)
-			fcs := doublylinkedtree.New()
+			fcs := protoarray.New()
 			s := &Service{
 				cfg:        &config{BeaconDB: beaconDB, WeakSubjectivityCheckpt: tt.checkpt, ForkChoiceStore: fcs},
 				wsVerifier: wv,
--- a/beacon-chain/builder/BUILD.bazel
+++ b/beacon-chain/builder/BUILD.bazel
@@ -1,4 +1,4 @@
-load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+load("@prysm//tools/go:def.bzl", "go_library")

 go_library(
    name = "go_default_library",
@@ -7,7 +7,7 @@ go_library(
        "option.go",
        "service.go",
    ],
-    importpath = "github.com/prysmaticlabs/prysm/v3/beacon-chain/builder",
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/builder",
    visibility = ["//visibility:public"],
    deps = [
        "//api/client/builder:go_default_library",
@@ -16,6 +16,8 @@ go_library(
        "//cmd/beacon-chain/flags:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
+        "//network:go_default_library",
+        "//network/authorization:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
@@ -26,18 +28,3 @@ go_library(
        "@io_opencensus_go//trace:go_default_library",
    ],
 )
-
-go_test(
-    name = "go_default_test",
-    srcs = ["service_test.go"],
-    embed = [":go_default_library"],
-    deps = [
-        "//api/client/builder/testing:go_default_library",
-        "//beacon-chain/blockchain/testing:go_default_library",
-        "//beacon-chain/db/testing:go_default_library",
-        "//encoding/bytesutil:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-        "//testing/assert:go_default_library",
-        "//testing/require:go_default_library",
-    ],
-)
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .3.0
 .0.0