adding more tests

migrating Beacon API code from eip4844 to deneb-integration (#12568 )
2026-01-09 21:38:05 -05:00 · 2023-07-07 10:14:44 -05:00 · 2023-06-30 14:13:37 -05:00 · 2023-06-28 14:51:48 -05:00 · 2023-06-28 17:16:30 +00:00 · 2023-06-27 06:45:15 -07:00
544 changed files with 45368 additions and 8792 deletions
--- a/.bazelrc
+++ b/.bazelrc
@@ -3,6 +3,7 @@ import %workspace%/build/bazelrc/convenience.bazelrc
 import %workspace%/build/bazelrc/correctness.bazelrc
 import %workspace%/build/bazelrc/cross.bazelrc
 import %workspace%/build/bazelrc/debug.bazelrc
+import %workspace%/build/bazelrc/hermetic-cc.bazelrc
 import %workspace%/build/bazelrc/performance.bazelrc

 # E2E run with debug gotag
@@ -14,7 +15,7 @@ coverage --define=coverage_enabled=1
 # Stamp binaries with git information
 build --workspace_status_command=./hack/workspace_status.sh

-build --define blst_disabled=false
+build --define blst_disabled=false --define blst_modern=true
 run --define blst_disabled=false

 build:blst_disabled --define blst_disabled=true
@@ -27,30 +28,7 @@ build:minimal --@io_bazel_rules_go//go/config:tags=minimal
 build:release --compilation_mode=opt
 build:release --stamp

-# LLVM compiler for building C/C++ dependencies.
-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
-build:asan --linkopt -fsanitize=address,undefined
-build:asan --copt -fno-sanitize=vptr,function
-build:asan --linkopt -fno-sanitize=vptr,function
-build:asan --copt -DADDRESS_SANITIZER=1
-build:asan --copt -D__SANITIZE_ADDRESS__
-build:asan --linkopt -ldl
-
-build:llvm-asan --config=llvm
-build:llvm-asan --config=asan
-build:llvm-asan --linkopt -fuse-ld=ld.lld
-
-build:fuzz --@io_bazel_rules_go//go/config:tags=fuzz
-
 # Build binary with cgo symbolizer for debugging / profiling.
-build:cgo_symbolizer --config=llvm
 build:cgo_symbolizer --copt=-g
 build:cgo_symbolizer --define=USE_CGO_SYMBOLIZER=true
 build:cgo_symbolizer -c dbg
@@ -59,7 +37,7 @@ build:cgo_symbolizer --define=gotags=cgosymbolizer_enabled
 # toolchain build debug configs
 #------------------------------
 build:debug --sandbox_debug
-build:debug --toolchain_resolution_debug
+build:debug --toolchain_resolution_debug=".*"
 build:debug --verbose_failures
 build:debug -s

--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-6.1.0
+6.2.1
--- a/.buildkite-bazelrc
+++ b/.buildkite-bazelrc
@@ -43,4 +43,12 @@ build --flaky_test_attempts=5

 # Better caching
 build:nostamp --nostamp
-build:nostamp --workspace_status_command=./hack/workspace_status_ci.sh
+
+# Build metadata
+build --build_metadata=ROLE=CI
+build --build_metadata=REPO_URL=https://github.com/prysmaticlabs/prysm.git
+build --workspace_status_command=./hack/workspace_status_ci.sh
+
+# Buildbuddy
+build --bes_results_url=https://app.buildbuddy.io/invocation/
+build --bes_backend=grpcs://remote.buildbuddy.io
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -26,14 +26,14 @@ jobs:
    steps:
      - name: Checkout
        uses: actions/checkout@v2
-      - name: Set up Go 1.19
+      - name: Set up Go 1.20
        uses: actions/setup-go@v3
        with:
-          go-version: 1.19
+          go-version: '1.20'
      - name: Run Gosec Security Scanner
        run: | # https://github.com/securego/gosec/issues/469
          export PATH=$PATH:$(go env GOPATH)/bin
-          go install github.com/securego/gosec/v2/cmd/gosec@v2.12.0
+          go install github.com/securego/gosec/v2/cmd/gosec@v2.15.0
          gosec -exclude=G307 -exclude-dir=crypto/bls/herumi ./...

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

-      - name: Set up Go 1.19
+      - name: Set up Go 1.20
        uses: actions/setup-go@v3
        with:
-          go-version: 1.19
+          go-version: '1.20'
          id: go

      - name: Golangci-lint
        uses: golangci/golangci-lint-action@v3
        with:
-          version: v1.50.1
+          version: v1.52.2
          args: --config=.golangci.yml --out-${NO_FUTURE}format colored-line-number

  build:
@@ -62,7 +62,7 @@ jobs:
      - name: Set up Go 1.x
        uses: actions/setup-go@v2
        with:
-          go-version: 1.19
+          go-version: '1.20'
        id: go

      - name: Check out code into the Go module directory
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,6 +1,6 @@
 # Contribution Guidelines

-Note: The latest and most up to date documenation can be found on our [docs portal](https://docs.prylabs.network/docs/contribute/contribution-guidelines).
+Note: The latest and most up-to-date documentation can be found on our [docs portal](https://docs.prylabs.network/docs/contribute/contribution-guidelines).

 Excited by our work and want to get involved in building out our sharding releases? Or maybe you haven't learned as much about the Ethereum protocol but are a savvy developer? 

@@ -10,9 +10,9 @@ You can explore our [Open Issues](https://github.com/prysmaticlabs/prysm/issues)

 **1. Set up Prysm following the instructions in README.md.**

-**2. Fork the prysm repo.**
+**2. Fork the Prysm repo.**

-Sign in to your Github account or create a new account if you do not have one already. Then navigate your browser to https://github.com/prysmaticlabs/prysm/. In the upper right hand corner of the page, click “fork”. This will create a copy of the Prysm repo in your account.
+Sign in to your GitHub account or create a new account if you do not have one already. Then navigate your browser to https://github.com/prysmaticlabs/prysm/. In the upper right hand corner of the page, click “fork”. This will create a copy of the Prysm repo in your account.

 **3. Create a local clone of Prysm.**

@@ -23,7 +23,7 @@ $ git clone https://github.com/prysmaticlabs/prysm.git
 $ cd $GOPATH/src/github.com/prysmaticlabs/prysm
 ```

-**4. Link your local clone to the fork on your Github repo.**
+**4. Link your local clone to the fork on your GitHub repo.**

 ```
 $ git remote add myprysmrepo https://github.com/<your_github_user_name>/prysm.git
@@ -68,7 +68,7 @@ $ go test <file_you_are_working_on>
 $ git add --all
 ```

-This command stages all of the files that you have changed. You can add individual files by specifying the file name or names and eliminating the “-- all”.
+This command stages all the files that you have changed. You can add individual files by specifying the file name or names and eliminating the “-- all”.

 **11. Commit the file or files.**

@@ -96,8 +96,7 @@ If there are conflicts between your edits and those made by others since you sta
 $ git status
 ```

-Open those files one at a time and you
-will see lines inserted by Git that identify the conflicts:
+Open those files one at a time, and you will see lines inserted by Git that identify the conflicts:

 ```
 <<<<<< HEAD
@@ -119,7 +118,7 @@ $ git push myrepo feature-in-progress-branch

 **15. Check to be sure your fork of the Prysm repo contains your feature branch with the latest edits.**

-Navigate to your fork of the repo on Github. On the upper left where the current branch is listed, change the branch to your feature-in-progress-branch. Open the files that you have worked on and check to make sure they include your changes.
+Navigate to your fork of the repo on GitHub. On the upper left where the current branch is listed, change the branch to your feature-in-progress-branch. Open the files that you have worked on and check to make sure they include your changes.

 **16. Create a pull request.**

@@ -151,7 +150,7 @@ pick 	hash 	fix a bug
 pick 	hash 	add a feature
 ```

-Replace the word pick with the word “squash” for every line but the first so you end with ….
+Replace the word pick with the word “squash” for every line but the first, so you end with ….

 ```
 pick    hash	do some work
@@ -178,7 +177,7 @@ We consider two types of contributions to our repo and categorize them as follow
 Anyone can become a part-time contributor and help out on implementing Ethereum consensus. The responsibilities of a part-time contributor include:

 -   Engaging in Gitter conversations, asking the questions on how to begin contributing to the project
-   Opening up github issues to express interest in code to implement
+-   Opening up GitHub issues to express interest in code to implement
 -   Opening up PRs referencing any open issue in the repo. PRs should include:
    -   Detailed context of what would be required for merge
    -   Tests that are consistent with how other tests are written in our implementation
@@ -188,12 +187,12 @@ Anyone can become a part-time contributor and help out on implementing Ethereum

 ### Core Contributors

-Core contributors are remote contractors of Prysmatic Labs, LLC. and are considered critical team members of our organization. Core devs have all of the responsibilities of part-time contributors plus the majority of the following:
+Core contributors are remote contractors of Prysmatic Labs, LLC. and are considered critical team members of our organization. Core devs have all the responsibilities of part-time contributors plus the majority of the following:

 -   Stay up to date on the latest beacon chain specification
-   Monitor github issues and PR’s to make sure owner, labels, descriptions are correct
+-   Monitor GitHub issues and PR’s to make sure owner, labels, descriptions are correct
 -   Formulate independent ideas, suggest new work to do, point out improvements to existing approaches
-   Participate in code review, ensure code quality is excellent, and have ensure high code coverage
+-   Participate in code review, ensure code quality is excellent, and ensure high code coverage
 -   Help with social media presence, write bi-weekly development update
 -   Represent Prysmatic Labs at events to help spread the word on scalability research and solutions

--- a/README.md
+++ b/README.md
@@ -4,14 +4,14 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/prysmaticlabs/prysm)](https://goreportcard.com/report/github.com/prysmaticlabs/prysm)
 [![Consensus_Spec_Version 1.3.0](https://img.shields.io/badge/Consensus%20Spec%20Version-v1.3.0-blue.svg)](https://github.com/ethereum/consensus-specs/tree/v1.3.0)
 [![Execution_API_Version 1.0.0-beta.2](https://img.shields.io/badge/Execution%20API%20Version-v1.0.0.beta.2-blue.svg)](https://github.com/ethereum/execution-apis/tree/v1.0.0-beta.2/src/engine)
-[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/CTYGPUJ)
+[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysmaticlabs)
 [![GitPOAP Badge](https://public-api.gitpoap.io/v1/repo/prysmaticlabs/prysm/badge)](https://www.gitpoap.io/gh/prysmaticlabs/prysm)

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

 ### Getting Started

-A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the [official documentation portal](https://docs.prylabs.network). If you still have questions, feel free to stop by our [Discord](https://discord.gg/CTYGPUJ).
+A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the [official documentation portal](https://docs.prylabs.network). If you still have questions, feel free to stop by our [Discord](https://discord.gg/prysmaticlabs).

 ### Staking on Mainnet

--- a/46
+++ b/46
@@ -16,27 +16,37 @@ load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")

 rules_pkg_dependencies()

+HERMETIC_CC_TOOLCHAIN_VERSION = "v2.0.0"
+
 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"],
+    name = "hermetic_cc_toolchain",
+    sha256 = "57f03a6c29793e8add7bd64186fc8066d23b5ffd06fe9cc6b0b8c499914d3a65",
+    urls = [
+        "https://mirror.bazel.build/github.com/uber/hermetic_cc_toolchain/releases/download/{0}/hermetic_cc_toolchain-{0}.tar.gz".format(HERMETIC_CC_TOOLCHAIN_VERSION),
+        "https://github.com/uber/hermetic_cc_toolchain/releases/download/{0}/hermetic_cc_toolchain-{0}.tar.gz".format(HERMETIC_CC_TOOLCHAIN_VERSION),
+    ],
 )

-load("@com_grail_bazel_toolchain//toolchain:deps.bzl", "bazel_toolchain_dependencies")
+load("@hermetic_cc_toolchain//toolchain:defs.bzl", zig_toolchains = "toolchains")

-bazel_toolchain_dependencies()
+zig_toolchains()

-load("@com_grail_bazel_toolchain//toolchain:rules.bzl", "llvm_toolchain")
-
-llvm_toolchain(
-    name = "llvm_toolchain",
-    llvm_version = "13.0.1",
+# Register zig sdk toolchains with support for Ubuntu 20.04 (Focal Fossa) which has an EOL date of April, 2025.
+# For ubuntu glibc support, see https://launchpad.net/ubuntu/+source/glibc
+register_toolchains(
+    "@zig_sdk//toolchain:linux_amd64_gnu.2.31",
+    "@zig_sdk//toolchain:linux_arm64_gnu.2.31",
+    # Hermetic cc toolchain is not yet supported on darwin. Sysroot needs to be provided.
+    # See https://github.com/uber/hermetic_cc_toolchain#osx-sysroot
+    #    "@zig_sdk//toolchain:darwin_amd64",
+    #    "@zig_sdk//toolchain:darwin_arm64",
+    # Windows builds are not supported yet.
+    #    "@zig_sdk//toolchain:windows_amd64",
 )

-load("@llvm_toolchain//:toolchains.bzl", "llvm_register_toolchains")
+load("@prysm//tools/cross-toolchain:darwin_cc_hack.bzl", "configure_nonhermetic_darwin")

-llvm_register_toolchains()
+configure_nonhermetic_darwin()

 load("@prysm//tools/cross-toolchain:prysm_toolchains.bzl", "configure_prysm_toolchains")

@@ -205,7 +215,7 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.3.0"
+consensus_spec_version = "v1.4.0-alpha.2"

 bls_test_version = "v0.1.1"

@@ -221,7 +231,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "1c806e04ac5e3779032c06a6009350b3836b6809bb23812993d6ececd7047cf5",
+    sha256 = "bfba887cbe043907adf884cf6d18f2e8a31e34e9245397b84af1f54ed22b706a",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

@@ -237,7 +247,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "2b42796dc5ccd9f1246032d0c17663e20f70334ff7e00325f0fc3af28cb24186",
+    sha256 = "9ff77bef0ca1e39bcee2769075c89f0f91fb8f89ad38a1b3e0c31cf6732650ad",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

@@ -253,7 +263,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "231e3371e81ce9acde65d2910ec4580587e74dbbcfcbd9c675e473e022deec8a",
+    sha256 = "fbcc3c9898110c675e5de9c27cb667ad7cadf930db7ebb5c6bba15d7be95bf8a",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

@@ -268,7 +278,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    sha256 = "219b74d95664ea7e8dfbf31162dfa206b9c0cf45919ea86db5fa0f8902977e3c",
+    sha256 = "9fff1bcdd0e5857797197800db091c3675b2c11b54f704fe4de1ba683bed7ba5",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
--- a/api/client/BUILD.bazel
+++ b/api/client/BUILD.bazel
@@ -0,0 +1,20 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "client.go",
+        "errors.go",
+        "options.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client",
+    visibility = ["//visibility:public"],
+    deps = ["@com_github_pkg_errors//:go_default_library"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["client_test.go"],
+    embed = [":go_default_library"],
+    deps = ["//testing/require:go_default_library"],
+)
--- a/api/client/beacon/BUILD.bazel
+++ b/api/client/beacon/BUILD.bazel
@@ -6,11 +6,11 @@ go_library(
        "checkpoint.go",
        "client.go",
        "doc.go",
-        "errors.go",
    ],
    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/beacon",
    visibility = ["//visibility:public"],
    deps = [
+        "//api/client:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
        "//beacon-chain/rpc/apimiddleware:go_default_library",
        "//beacon-chain/state:go_default_library",
@@ -39,6 +39,7 @@ go_test(
    ],
    embed = [":go_default_library"],
    deps = [
+        "//api/client:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
--- a/api/client/beacon/checkpoint.go
+++ b/api/client/beacon/checkpoint.go
@@ -6,10 +6,12 @@ import (
 	"path"

 	"github.com/pkg/errors"
+	base "github.com/prysmaticlabs/prysm/v4/api/client"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v4/encoding/ssz/detect"
 	"github.com/prysmaticlabs/prysm/v4/io/file"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
@@ -18,6 +20,8 @@ import (
 	"golang.org/x/mod/semver"
 )

+var errCheckpointBlockMismatch = errors.New("mismatch between checkpoint sync state and block")
+
 // OriginData represents the BeaconState and ReadOnlySignedBeaconBlock necessary to start an empty Beacon Node
 // using Checkpoint Sync.
 type OriginData struct {
@@ -74,37 +78,40 @@ 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)
+	slot := s.LatestBlockHeader().Slot
+	bb, err := client.GetBlock(ctx, IdFromSlot(slot))
 	if err != nil {
-		return nil, errors.Wrapf(err, "failed to compute htr for finalized state at slot=%d", s.Slot())
-	}
-	header := s.LatestBlockHeader()
-	header.StateRoot = sr[:]
-	br, err := header.HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error while computing block root using state data")
-	}
-
-	bb, err := client.GetBlock(ctx, IdFromRoot(br))
-	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by root = %#x", br)
+		return nil, errors.Wrapf(err, "error requesting block by slot = %d", slot)
 	}
 	b, err := vu.UnmarshalBeaconBlock(bb)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
 	}
-	realBlockRoot, err := b.Block().HashTreeRoot()
+	br, err := b.Block().HashTreeRoot()
 	if err != nil {
 		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block")
 	}
+	bodyRoot, err := b.Block().Body().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block body")
+	}

-	log.Printf("BeaconState slot=%d, Block slot=%d", s.Slot(), b.Block().Slot())
-	log.Printf("BeaconState htr=%#x, Block state_root=%#x", sr, b.Block().StateRoot())
-	log.Printf("BeaconState latest_block_header htr=%#x, block htr=%#x", br, realBlockRoot)
+	sbr := bytesutil.ToBytes32(s.LatestBlockHeader().BodyRoot)
+	if sbr != bodyRoot {
+		return nil, errors.Wrapf(errCheckpointBlockMismatch, "state body root = %#x, block body root = %#x", sbr, bodyRoot)
+	}
+	sr, err := s.HashTreeRoot(ctx)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to compute htr for finalized state at slot=%d", s.Slot())
+	}
+
+	log.
+		WithField("block_slot", b.Block().Slot()).
+		WithField("state_slot", s.Slot()).
+		WithField("state_root", sr).
+		WithField("block_root", br).
+		Info("Downloaded checkpoint sync state and block.")
 	return &OriginData{
 		st: s,
 		b:  b,
@@ -140,7 +147,7 @@ func ComputeWeakSubjectivityCheckpoint(ctx context.Context, client *Client) (*We
 	ws, err := client.GetWeakSubjectivity(ctx)
 	if err != nil {
 		// a 404/405 is expected if querying an endpoint that doesn't support the weak subjectivity checkpoint api
-		if !errors.Is(err, ErrNotOK) {
+		if !errors.Is(err, base.ErrNotOK) {
 			return nil, errors.Wrap(err, "unexpected API response for prysm-only weak subjectivity checkpoint API")
 		}
 		// fall back to vanilla Beacon Node API method
--- a/api/client/beacon/checkpoint_test.go
+++ b/api/client/beacon/checkpoint_test.go
@@ -7,9 +7,9 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"net/url"
 	"testing"

+	"github.com/prysmaticlabs/prysm/v4/api/client"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	blocktest "github.com/prysmaticlabs/prysm/v4/consensus-types/blocks/testing"
@@ -66,11 +66,7 @@ func TestMarshalToEnvelope(t *testing.T) {
 }

 func TestFallbackVersionCheck(t *testing.T) {
-	c := &Client{
-		hc:      &http.Client{},
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
-	c.hc.Transport = &testRT{rt: func(req *http.Request) (*http.Response, error) {
+	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
 		res := &http.Response{Request: req}
 		switch req.URL.Path {
 		case getNodeVersionPath:
@@ -88,12 +84,13 @@ func TestFallbackVersionCheck(t *testing.T) {
 		case getWeakSubjectivityPath:
 			res.StatusCode = http.StatusNotFound
 		}
-
 		return res, nil
 	}}

+	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
+	require.NoError(t, err)
 	ctx := context.Background()
-	_, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
+	_, err = ComputeWeakSubjectivityCheckpoint(ctx, c)
 	require.ErrorIs(t, err, errUnsupportedPrysmCheckpointVersion)
 }

@@ -170,44 +167,41 @@ func TestDownloadWeakSubjectivityCheckpoint(t *testing.T) {
 		Epoch:     epoch,
 	}

-	hc := &http.Client{
-		Transport: &testRT{rt: func(req *http.Request) (*http.Response, error) {
-			res := &http.Response{Request: req}
-			switch req.URL.Path {
-			case getWeakSubjectivityPath:
-				res.StatusCode = http.StatusOK
-				cp := struct {
-					Epoch string `json:"epoch"`
-					Root  string `json:"root"`
-				}{
-					Epoch: fmt.Sprintf("%d", slots.ToEpoch(b.Block().Slot())),
-					Root:  fmt.Sprintf("%#x", bRoot),
-				}
-				wsr := struct {
-					Checkpoint interface{} `json:"ws_checkpoint"`
-					StateRoot  string      `json:"state_root"`
-				}{
-					Checkpoint: cp,
-					StateRoot:  fmt.Sprintf("%#x", wRoot),
-				}
-				rb, err := marshalToEnvelope(wsr)
-				require.NoError(t, err)
-				res.Body = io.NopCloser(bytes.NewBuffer(rb))
-			case renderGetStatePath(IdFromSlot(wSlot)):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(wsSerialized))
-			case renderGetBlockPath(IdFromRoot(bRoot)):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(serBlock))
+	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
+		res := &http.Response{Request: req}
+		switch req.URL.Path {
+		case getWeakSubjectivityPath:
+			res.StatusCode = http.StatusOK
+			cp := struct {
+				Epoch string `json:"epoch"`
+				Root  string `json:"root"`
+			}{
+				Epoch: fmt.Sprintf("%d", slots.ToEpoch(b.Block().Slot())),
+				Root:  fmt.Sprintf("%#x", bRoot),
 			}
+			wsr := struct {
+				Checkpoint interface{} `json:"ws_checkpoint"`
+				StateRoot  string      `json:"state_root"`
+			}{
+				Checkpoint: cp,
+				StateRoot:  fmt.Sprintf("%#x", wRoot),
+			}
+			rb, err := marshalToEnvelope(wsr)
+			require.NoError(t, err)
+			res.Body = io.NopCloser(bytes.NewBuffer(rb))
+		case renderGetStatePath(IdFromSlot(wSlot)):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(wsSerialized))
+		case renderGetBlockPath(IdFromRoot(bRoot)):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(serBlock))
+		}

-			return res, nil
-		}},
-	}
-	c := &Client{
-		hc:      hc,
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
+		return res, nil
+	}}
+
+	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
+	require.NoError(t, err)

 	wsd, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
 	require.NoError(t, err)
@@ -266,42 +260,39 @@ func TestDownloadBackwardsCompatibleCombined(t *testing.T) {
 	wsSerialized, err := wst.MarshalSSZ()
 	require.NoError(t, err)

-	hc := &http.Client{
-		Transport: &testRT{rt: func(req *http.Request) (*http.Response, error) {
-			res := &http.Response{Request: req}
-			switch req.URL.Path {
-			case getNodeVersionPath:
-				res.StatusCode = http.StatusOK
-				b := bytes.NewBuffer(nil)
-				d := struct {
-					Version string `json:"version"`
-				}{
-					Version: "Lighthouse/v0.1.5 (Linux x86_64)",
-				}
-				encoded, err := marshalToEnvelope(d)
-				require.NoError(t, err)
-				b.Write(encoded)
-				res.Body = io.NopCloser(b)
-			case getWeakSubjectivityPath:
-				res.StatusCode = http.StatusNotFound
-			case renderGetStatePath(IdHead):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(serialized))
-			case renderGetStatePath(IdFromSlot(wSlot)):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(wsSerialized))
-			case renderGetBlockPath(IdFromRoot(bRoot)):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(serBlock))
+	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
+		res := &http.Response{Request: req}
+		switch req.URL.Path {
+		case getNodeVersionPath:
+			res.StatusCode = http.StatusOK
+			b := bytes.NewBuffer(nil)
+			d := struct {
+				Version string `json:"version"`
+			}{
+				Version: "Lighthouse/v0.1.5 (Linux x86_64)",
 			}
+			encoded, err := marshalToEnvelope(d)
+			require.NoError(t, err)
+			b.Write(encoded)
+			res.Body = io.NopCloser(b)
+		case getWeakSubjectivityPath:
+			res.StatusCode = http.StatusNotFound
+		case renderGetStatePath(IdHead):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(serialized))
+		case renderGetStatePath(IdFromSlot(wSlot)):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(wsSerialized))
+		case renderGetBlockPath(IdFromRoot(bRoot)):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(serBlock))
+		}

-			return res, nil
-		}},
-	}
-	c := &Client{
-		hc:      hc,
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
+		return res, nil
+	}}
+
+	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
+	require.NoError(t, err)

 	wsPub, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
 	require.NoError(t, err)
@@ -315,21 +306,16 @@ func TestGetWeakSubjectivityEpochFromHead(t *testing.T) {
 	st, expectedEpoch := defaultTestHeadState(t, params.MainnetConfig())
 	serialized, err := st.MarshalSSZ()
 	require.NoError(t, err)
-	hc := &http.Client{
-		Transport: &testRT{rt: func(req *http.Request) (*http.Response, error) {
-			res := &http.Response{Request: req}
-			switch req.URL.Path {
-			case renderGetStatePath(IdHead):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(serialized))
-			}
-			return res, nil
-		}},
-	}
-	c := &Client{
-		hc:      hc,
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
+	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
+		res := &http.Response{Request: req}
+		if req.URL.Path == renderGetStatePath(IdHead) {
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(serialized))
+		}
+		return res, nil
+	}}
+	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
+	require.NoError(t, err)
 	actualEpoch, err := getWeakSubjectivityEpochFromHead(context.Background(), c)
 	require.NoError(t, err)
 	require.Equal(t, expectedEpoch, actualEpoch)
@@ -448,29 +434,24 @@ func TestDownloadFinalizedData(t *testing.T) {
 	ms, err := st.MarshalSSZ()
 	require.NoError(t, err)

-	hc := &http.Client{
-		Transport: &testRT{rt: func(req *http.Request) (*http.Response, error) {
-			res := &http.Response{Request: req}
-			switch req.URL.Path {
-			case renderGetStatePath(IdFinalized):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(ms))
-			case renderGetBlockPath(IdFromRoot(br)):
-				res.StatusCode = http.StatusOK
-				res.Body = io.NopCloser(bytes.NewBuffer(mb))
-			default:
-				res.StatusCode = http.StatusInternalServerError
-				res.Body = io.NopCloser(bytes.NewBufferString(""))
-			}
-
-			return res, nil
-		}},
-	}
-	c := &Client{
-		hc:      hc,
-		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
-	}
+	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
+		res := &http.Response{Request: req}
+		switch req.URL.Path {
+		case renderGetStatePath(IdFinalized):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(ms))
+		case renderGetBlockPath(IdFromSlot(b.Block().Slot())):
+			res.StatusCode = http.StatusOK
+			res.Body = io.NopCloser(bytes.NewBuffer(mb))
+		default:
+			res.StatusCode = http.StatusInternalServerError
+			res.Body = io.NopCloser(bytes.NewBufferString(""))
+		}

+		return res, nil
+	}}
+	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
+	require.NoError(t, err)
 	// sanity check before we go through checkpoint
 	// make sure we can download the state and unmarshal it with the VersionedUnmarshaler
 	sb, err := c.GetState(ctx, IdFinalized)
--- a/api/client/beacon/client.go
+++ b/api/client/beacon/client.go
@@ -5,8 +5,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io"
-	"net"
 	"net/http"
 	"net/url"
 	"path"
@@ -14,8 +12,8 @@ import (
 	"sort"
 	"strconv"
 	"text/template"
-	"time"

+	"github.com/prysmaticlabs/prysm/v4/api/client"
 	"github.com/prysmaticlabs/prysm/v4/network/forks"
 	v1 "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"

@@ -54,8 +52,6 @@ const (
 	IdFinalized StateOrBlockId = "finalized"
 )

-var ErrMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
-
 // IdFromRoot encodes a block root in the format expected by the API in places where a root can be used to identify
 // a BeaconState or SignedBeaconBlock.
 func IdFromRoot(r [32]byte) StateOrBlockId {
@@ -85,96 +81,22 @@ func idTemplate(ts string) func(StateOrBlockId) string {
 	return f
 }

-// 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
-	}
+func renderGetBlockPath(id StateOrBlockId) string {
+	return path.Join(getSignedBlockPath, string(id))
 }

 // Client provides a collection of helper methods for calling the Eth Beacon Node API endpoints.
 type Client struct {
-	hc      *http.Client
-	baseURL *url.URL
+	*client.Client
 }

-// NewClient constructs a new client with the provided options (ex WithTimeout).
-// `host` is the base host + port used to construct request urls. This value can be
-// a URL string, or NewClient will assume an http endpoint if just `host:port` is used.
-func NewClient(host string, opts ...ClientOpt) (*Client, error) {
-	u, err := urlForHost(host)
+// NewClient returns a new Client that includes functions for rest calls to Beacon API.
+func NewClient(host string, opts ...client.ClientOpt) (*Client, error) {
+	c, err := client.NewClient(host, opts...)
 	if err != nil {
 		return nil, err
 	}
-	c := &Client{
-		hc:      &http.Client{},
-		baseURL: u,
-	}
-	for _, o := range opts {
-		o(c)
-	}
-	return c, nil
-}
-
-func urlForHost(h string) (*url.URL, error) {
-	// try to parse as url (being permissive)
-	u, err := url.Parse(h)
-	if err == nil && u.Host != "" {
-		return u, nil
-	}
-	// try to parse as host:port
-	host, port, err := net.SplitHostPort(h)
-	if err != nil {
-		return nil, ErrMalformedHostname
-	}
-	return &url.URL{Host: fmt.Sprintf("%s:%s", host, port), Scheme: "http"}, nil
-}
-
-// NodeURL returns a human-readable string representation of the beacon node base url.
-func (c *Client) NodeURL() string {
-	return c.baseURL.String()
-}
-
-type reqOption func(*http.Request)
-
-func withSSZEncoding() reqOption {
-	return func(req *http.Request) {
-		req.Header.Set("Accept", "application/octet-stream")
-	}
-}
-
-// get is a generic, opinionated GET function to reduce boilerplate amongst the getters in this package.
-func (c *Client) get(ctx context.Context, path string, opts ...reqOption) ([]byte, error) {
-	u := c.baseURL.ResolveReference(&url.URL{Path: path})
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
-	if err != nil {
-		return nil, err
-	}
-	for _, o := range opts {
-		o(req)
-	}
-	r, err := c.hc.Do(req)
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		err = r.Body.Close()
-	}()
-	if r.StatusCode != http.StatusOK {
-		return nil, non200Err(r)
-	}
-	b, err := io.ReadAll(r.Body)
-	if err != nil {
-		return nil, errors.Wrap(err, "error reading http response body from GetBlock")
-	}
-	return b, nil
-}
-
-func renderGetBlockPath(id StateOrBlockId) string {
-	return path.Join(getSignedBlockPath, string(id))
+	return &Client{c}, nil
 }

 // GetBlock retrieves the SignedBeaconBlock for the given block id.
@@ -184,7 +106,7 @@ func renderGetBlockPath(id StateOrBlockId) string {
 // The return value contains the ssz-encoded bytes.
 func (c *Client) GetBlock(ctx context.Context, blockId StateOrBlockId) ([]byte, error) {
 	blockPath := renderGetBlockPath(blockId)
-	b, err := c.get(ctx, blockPath, withSSZEncoding())
+	b, err := c.Get(ctx, blockPath, client.WithSSZEncoding())
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting state by id = %s", blockId)
 	}
@@ -199,7 +121,7 @@ var getBlockRootTpl = idTemplate(getBlockRootPath)
 // for the named identifiers.
 func (c *Client) GetBlockRoot(ctx context.Context, blockId StateOrBlockId) ([32]byte, error) {
 	rootPath := getBlockRootTpl(blockId)
-	b, err := c.get(ctx, rootPath)
+	b, err := c.Get(ctx, rootPath)
 	if err != nil {
 		return [32]byte{}, errors.Wrapf(err, "error requesting block root by id = %s", blockId)
 	}
@@ -222,7 +144,7 @@ var getForkTpl = idTemplate(getForkForStatePath)
 // <slot>, <hex encoded blockRoot with 0x prefix>. Variables of type StateOrBlockId are exported by this package
 // for the named identifiers.
 func (c *Client) GetFork(ctx context.Context, stateId StateOrBlockId) (*ethpb.Fork, error) {
-	body, err := c.get(ctx, getForkTpl(stateId))
+	body, err := c.Get(ctx, getForkTpl(stateId))
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting fork by state id = %s", stateId)
 	}
@@ -238,7 +160,7 @@ func (c *Client) GetFork(ctx context.Context, stateId StateOrBlockId) (*ethpb.Fo

 // GetForkSchedule retrieve all forks, past present and future, of which this node is aware.
 func (c *Client) GetForkSchedule(ctx context.Context) (forks.OrderedSchedule, error) {
-	body, err := c.get(ctx, getForkSchedulePath)
+	body, err := c.Get(ctx, getForkSchedulePath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting fork schedule")
 	}
@@ -256,7 +178,7 @@ func (c *Client) GetForkSchedule(ctx context.Context) (forks.OrderedSchedule, er

 // GetConfigSpec retrieve the current configs of the network used by the beacon node.
 func (c *Client) GetConfigSpec(ctx context.Context) (*v1.SpecResponse, error) {
-	body, err := c.get(ctx, getConfigSpecPath)
+	body, err := c.Get(ctx, getConfigSpecPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting configSpecPath")
 	}
@@ -279,7 +201,7 @@ var versionRE = regexp.MustCompile(`^(\w+)/(v\d+\.\d+\.\d+[-a-zA-Z0-9]*)\s*/?(.*
 func parseNodeVersion(v string) (*NodeVersion, error) {
 	groups := versionRE.FindStringSubmatch(v)
 	if len(groups) != 4 {
-		return nil, errors.Wrapf(ErrInvalidNodeVersion, "could not be parsed: %s", v)
+		return nil, errors.Wrapf(client.ErrInvalidNodeVersion, "could not be parsed: %s", v)
 	}
 	return &NodeVersion{
 		implementation: groups[1],
@@ -291,7 +213,7 @@ func parseNodeVersion(v string) (*NodeVersion, error) {
 // GetNodeVersion requests that the beacon node identify information about its implementation in a format
 // similar to a HTTP User-Agent field. ex: Lighthouse/v0.1.5 (Linux x86_64)
 func (c *Client) GetNodeVersion(ctx context.Context) (*NodeVersion, error) {
-	b, err := c.get(ctx, getNodeVersionPath)
+	b, err := c.Get(ctx, getNodeVersionPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting node version")
 	}
@@ -318,7 +240,7 @@ func renderGetStatePath(id StateOrBlockId) string {
 // The return value contains the ssz-encoded bytes.
 func (c *Client) GetState(ctx context.Context, stateId StateOrBlockId) ([]byte, error) {
 	statePath := path.Join(getStatePath, string(stateId))
-	b, err := c.get(ctx, statePath, withSSZEncoding())
+	b, err := c.Get(ctx, statePath, client.WithSSZEncoding())
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting state by id = %s", stateId)
 	}
@@ -331,7 +253,7 @@ func (c *Client) GetState(ctx context.Context, stateId StateOrBlockId) ([]byte,
 // - finds the highest non-skipped block preceding the epoch
 // - returns the htr of the found block and returns this + the value of state_root from the block
 func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData, error) {
-	body, err := c.get(ctx, getWeakSubjectivityPath)
+	body, err := c.Get(ctx, getWeakSubjectivityPath)
 	if err != nil {
 		return nil, err
 	}
@@ -362,7 +284,7 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 // SubmitChangeBLStoExecution calls a beacon API endpoint to set the withdrawal addresses based on the given signed messages.
 // If the API responds with something other than OK there will be failure messages associated to the corresponding request message.
 func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*apimiddleware.SignedBLSToExecutionChangeJson) error {
-	u := c.baseURL.ResolveReference(&url.URL{Path: changeBLStoExecutionPath})
+	u := c.BaseURL().ResolveReference(&url.URL{Path: changeBLStoExecutionPath})
 	body, err := json.Marshal(request)
 	if err != nil {
 		return errors.Wrap(err, "failed to marshal JSON")
@@ -372,7 +294,7 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*apim
 		return errors.Wrap(err, "invalid format, failed to create new POST request object")
 	}
 	req.Header.Set("Content-Type", "application/json")
-	resp, err := c.hc.Do(req)
+	resp, err := c.Do(req)
 	if err != nil {
 		return err
 	}
@@ -401,7 +323,7 @@ func (c *Client) SubmitChangeBLStoExecution(ctx context.Context, request []*apim
 // GetBLStoExecutionChanges gets all the set withdrawal messages in the node's operation pool.
 // Returns a struct representation of json response.
 func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*apimiddleware.BLSToExecutionChangesPoolResponseJson, error) {
-	body, err := c.get(ctx, changeBLStoExecutionPath)
+	body, err := c.Get(ctx, changeBLStoExecutionPath)
 	if err != nil {
 		return nil, err
 	}
@@ -413,23 +335,6 @@ func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*apimiddleware.B
 	return poolResponse, nil
 }

-func non200Err(response *http.Response) error {
-	bodyBytes, err := io.ReadAll(response.Body)
-	var body string
-	if err != nil {
-		body = "(Unable to read response body.)"
-	} else {
-		body = "response body:\n" + string(bodyBytes)
-	}
-	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
-	switch response.StatusCode {
-	case 404:
-		return errors.Wrap(ErrNotFound, msg)
-	default:
-		return errors.Wrap(ErrNotOK, msg)
-	}
-}
-
 type forkResponse struct {
 	PreviousVersion string `json:"previous_version"`
 	CurrentVersion  string `json:"current_version"`
--- a/api/client/beacon/client_test.go
+++ b/api/client/beacon/client_test.go
@@ -4,6 +4,7 @@ import (
 	"net/url"
 	"testing"

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

@@ -17,17 +18,17 @@ func TestParseNodeVersion(t *testing.T) {
 		{
 			name: "empty string",
 			v:    "",
-			err:  ErrInvalidNodeVersion,
+			err:  client.ErrInvalidNodeVersion,
 		},
 		{
 			name: "Prysm as the version string",
 			v:    "Prysm",
-			err:  ErrInvalidNodeVersion,
+			err:  client.ErrInvalidNodeVersion,
 		},
 		{
 			name: "semver only",
 			v:    "v2.0.6",
-			err:  ErrInvalidNodeVersion,
+			err:  client.ErrInvalidNodeVersion,
 		},
 		{
 			name: "complete version",
@@ -91,7 +92,7 @@ func TestValidHostname(t *testing.T) {
 		{
 			name:    "hostname without port",
 			hostArg: "mydomain.org",
-			err:     ErrMalformedHostname,
+			err:     client.ErrMalformedHostname,
 		},
 		{
 			name:    "hostname with port",
@@ -132,7 +133,7 @@ func TestValidHostname(t *testing.T) {
 				return
 			}
 			require.NoError(t, err)
-			require.Equal(t, c.joined, cl.baseURL.ResolveReference(&url.URL{Path: c.path}).String())
+			require.Equal(t, c.joined, cl.BaseURL().ResolveReference(&url.URL{Path: c.path}).String())
 		})
 	}
 }
--- a/api/client/beacon/errors.go
+++ b/api/client/beacon/errors.go
@@ -1,13 +0,0 @@
-package beacon
-
-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 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")
-
-// ErrInvalidNodeVersion indicates that the /eth/v1/node/version api response format was not recognized.
-var ErrInvalidNodeVersion = errors.New("invalid node version response")
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -11,12 +11,12 @@ go_library(
    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/builder",
    visibility = ["//visibility:public"],
    deps = [
+        "//config/fieldparams:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
-        "//math:go_default_library",
        "//monitoring/tracing:go_default_library",
        "//network:go_default_library",
        "//network/authorization:go_default_library",
@@ -40,6 +40,7 @@ go_test(
    data = glob(["testdata/**"]),
    embed = [":go_default_library"],
    deps = [
+        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/primitives:go_default_library",
--- a/api/client/builder/bid.go
+++ b/api/client/builder/bid.go
@@ -1,15 +1,12 @@
 package builder

 import (
-	"math/big"
-
 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
 	consensus_types "github.com/prysmaticlabs/prysm/v4/consensus-types"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v4/math"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 )
@@ -25,6 +22,7 @@ type SignedBid interface {
 // Bid is an interface describing the method set of a builder bid.
 type Bid interface {
 	Header() (interfaces.ExecutionData, error)
+	BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error)
 	Value() []byte
 	Pubkey() []byte
 	Version() int
@@ -117,6 +115,11 @@ func (b builderBid) Header() (interfaces.ExecutionData, error) {
 	return blocks.WrappedExecutionPayloadHeader(b.p.Header)
 }

+// BlindedBlobsBundle --
+func (b builderBid) BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error) {
+	return nil, errors.New("blinded blobs bundle not available before Deneb")
+}
+
 // Version --
 func (b builderBid) Version() int {
 	return version.Bellatrix
@@ -162,12 +165,13 @@ func WrappedBuilderBidCapella(p *ethpb.BuilderBidCapella) (Bid, error) {

 // Header returns the execution data interface.
 func (b builderBidCapella) Header() (interfaces.ExecutionData, error) {
-	if b.p == nil {
-		return nil, errors.New("builder bid is nil")
-	}
 	// We have to convert big endian to little endian because the value is coming from the execution layer.
-	v := big.NewInt(0).SetBytes(bytesutil.ReverseByteOrder(b.p.Value))
-	return blocks.WrappedExecutionPayloadHeaderCapella(b.p.Header, math.WeiToGwei(v))
+	return blocks.WrappedExecutionPayloadHeaderCapella(b.p.Header, blocks.PayloadValueToGwei(b.p.Value))
+}
+
+// BlindedBlobsBundle --
+func (b builderBidCapella) BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error) {
+	return nil, errors.New("blinded blobs bundle not available before Deneb")
 }

 // Version --
@@ -199,3 +203,90 @@ func (b builderBidCapella) HashTreeRoot() ([32]byte, error) {
 func (b builderBidCapella) HashTreeRootWith(hh *ssz.Hasher) error {
 	return b.p.HashTreeRootWith(hh)
 }
+
+type builderBidDeneb struct {
+	p *ethpb.BuilderBidDeneb
+}
+
+// WrappedBuilderBidDeneb is a constructor which wraps a protobuf bid into an interface.
+func WrappedBuilderBidDeneb(p *ethpb.BuilderBidDeneb) (Bid, error) {
+	w := builderBidDeneb{p: p}
+	if w.IsNil() {
+		return nil, consensus_types.ErrNilObjectWrapped
+	}
+	return w, nil
+}
+
+// Version --
+func (b builderBidDeneb) Version() int {
+	return version.Deneb
+}
+
+// Value --
+func (b builderBidDeneb) Value() []byte {
+	return b.p.Value
+}
+
+// Pubkey --
+func (b builderBidDeneb) Pubkey() []byte {
+	return b.p.Pubkey
+}
+
+// IsNil --
+func (b builderBidDeneb) IsNil() bool {
+	return b.p == nil
+}
+
+// HashTreeRoot --
+func (b builderBidDeneb) HashTreeRoot() ([32]byte, error) {
+	return b.p.HashTreeRoot()
+}
+
+// HashTreeRootWith --
+func (b builderBidDeneb) HashTreeRootWith(hh *ssz.Hasher) error {
+	return b.p.HashTreeRootWith(hh)
+}
+
+// Header --
+func (b builderBidDeneb) Header() (interfaces.ExecutionData, error) {
+	// We have to convert big endian to little endian because the value is coming from the execution layer.
+	return blocks.WrappedExecutionPayloadHeaderDeneb(b.p.Header, blocks.PayloadValueToGwei(b.p.Value))
+}
+
+// BlindedBlobsBundle --
+func (b builderBidDeneb) BlindedBlobsBundle() (*enginev1.BlindedBlobsBundle, error) {
+	return b.p.BlindedBlobsBundle, nil
+}
+
+type signedBuilderBidDeneb struct {
+	p *ethpb.SignedBuilderBidDeneb
+}
+
+// WrappedSignedBuilderBidDeneb is a constructor which wraps a protobuf signed bit into an interface.
+func WrappedSignedBuilderBidDeneb(p *ethpb.SignedBuilderBidDeneb) (SignedBid, error) {
+	w := signedBuilderBidDeneb{p: p}
+	if w.IsNil() {
+		return nil, consensus_types.ErrNilObjectWrapped
+	}
+	return w, nil
+}
+
+// Message --
+func (b signedBuilderBidDeneb) Message() (Bid, error) {
+	return WrappedBuilderBidDeneb(b.p.Message)
+}
+
+// Signature --
+func (b signedBuilderBidDeneb) Signature() []byte {
+	return b.p.Signature
+}
+
+// Version --
+func (b signedBuilderBidDeneb) Version() int {
+	return version.Deneb
+}
+
+// IsNil --
+func (b signedBuilderBidDeneb) IsNil() bool {
+	return b.p == nil
+}
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -11,7 +11,6 @@ import (
 	"net/url"
 	"strings"
 	"text/template"
-	"time"

 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
@@ -20,6 +19,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/monitoring/tracing"
 	"github.com/prysmaticlabs/prysm/v4/network"
 	"github.com/prysmaticlabs/prysm/v4/network/authorization"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	log "github.com/sirupsen/logrus"
@@ -36,7 +36,6 @@ 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 errNotBlinded = errors.New("submitted block is not blinded")
-var submitBlindedBlockTimeout = 3 * time.Second

 // ClientOpt is a functional option for the Client type (http.Client wrapper)
 type ClientOpt func(*Client)
@@ -88,7 +87,7 @@ type BuilderClient interface {
 	NodeURL() string
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, error)
+	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error)
 	Status(ctx context.Context) error
 }

@@ -222,6 +221,16 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 		return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
 	}
 	switch strings.ToLower(v.Version) {
+	case strings.ToLower(version.String(version.Deneb)):
+		hr := &ExecHeaderResponseDeneb{}
+		if err := json.Unmarshal(hb, hr); err != nil {
+			return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
+		}
+		p, err := hr.ToProto()
+		if err != nil {
+			return nil, errors.Wrapf(err, "could not extract proto message from header")
+		}
+		return WrappedSignedBuilderBidDeneb(p)
 	case strings.ToLower(version.String(version.Capella)):
 		hr := &ExecHeaderResponseCapella{}
 		if err := json.Unmarshal(hb, hr); err != nil {
@@ -276,79 +285,115 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid

 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
-func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, error) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	if !sb.IsBlinded() {
-		return nil, errNotBlinded
+		return nil, nil, errNotBlinded
 	}
 	switch sb.Version() {
 	case version.Bellatrix:
 		psb, err := sb.PbBlindedBellatrixBlock()
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not get protobuf block")
+			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
 		b := &SignedBlindedBeaconBlockBellatrix{SignedBlindedBeaconBlockBellatrix: psb}
 		body, err := json.Marshal(b)
 		if err != nil {
-			return nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockBellatrix value body in SubmitBlindedBlock")
+			return nil, nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockBellatrix value body in SubmitBlindedBlock")
 		}

-		ctx, cancel := context.WithTimeout(ctx, submitBlindedBlockTimeout)
-		defer cancel()
 		versionOpt := func(r *http.Request) {
 			r.Header.Add("Eth-Consensus-Version", version.String(version.Bellatrix))
 		}
 		rb, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), versionOpt)

 		if err != nil {
-			return nil, errors.Wrap(err, "error posting the SignedBlindedBeaconBlockBellatrix to the builder api")
+			return nil, nil, errors.Wrap(err, "error posting the SignedBlindedBeaconBlockBellatrix to the builder api")
 		}
 		ep := &ExecPayloadResponse{}
 		if err := json.Unmarshal(rb, ep); err != nil {
-			return nil, errors.Wrap(err, "error unmarshaling the builder SubmitBlindedBlock response")
+			return nil, nil, errors.Wrap(err, "error unmarshaling the builder SubmitBlindedBlock response")
 		}
 		if strings.ToLower(ep.Version) != version.String(version.Bellatrix) {
-			return nil, errors.New("not a bellatrix payload")
+			return nil, nil, errors.New("not a bellatrix payload")
 		}
 		p, err := ep.ToProto()
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not extract proto message from payload")
+			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
 		}
-		return blocks.WrappedExecutionPayload(p)
+		payload, err := blocks.WrappedExecutionPayload(p)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
+		}
+		return payload, nil, nil
 	case version.Capella:
 		psb, err := sb.PbBlindedCapellaBlock()
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not get protobuf block")
+			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
 		}
 		b := &SignedBlindedBeaconBlockCapella{SignedBlindedBeaconBlockCapella: psb}
 		body, err := json.Marshal(b)
 		if err != nil {
-			return nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockCapella value body in SubmitBlindedBlockCapella")
+			return nil, nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockCapella value body in SubmitBlindedBlockCapella")
 		}

-		ctx, cancel := context.WithTimeout(ctx, submitBlindedBlockTimeout)
-		defer cancel()
 		versionOpt := func(r *http.Request) {
 			r.Header.Add("Eth-Consensus-Version", version.String(version.Capella))
 		}
 		rb, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), versionOpt)

 		if err != nil {
-			return nil, errors.Wrap(err, "error posting the SignedBlindedBeaconBlockCapella to the builder api")
+			return nil, nil, errors.Wrap(err, "error posting the SignedBlindedBeaconBlockCapella to the builder api")
 		}
 		ep := &ExecPayloadResponseCapella{}
 		if err := json.Unmarshal(rb, ep); err != nil {
-			return nil, errors.Wrap(err, "error unmarshaling the builder SubmitBlindedBlockCapella response")
+			return nil, nil, errors.Wrap(err, "error unmarshaling the builder SubmitBlindedBlockCapella response")
 		}
 		if strings.ToLower(ep.Version) != version.String(version.Capella) {
-			return nil, errors.New("not a capella payload")
+			return nil, nil, errors.New("not a capella payload")
 		}
 		p, err := ep.ToProto()
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not extract proto message from payload")
+			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
 		}
-		return blocks.WrappedExecutionPayloadCapella(p, 0)
+		payload, err := blocks.WrappedExecutionPayloadCapella(p, 0)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
+		}
+		return payload, nil, nil
+	case version.Deneb:
+		psb, err := sb.PbBlindedDenebBlock()
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "could not get protobuf block")
+		}
+
+		b := &ethpb.SignedBlindedBeaconBlockAndBlobsDeneb{Block: psb, Blobs: blobs}
+		body, err := json.Marshal(b)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockDeneb value body in SubmitBlindedBlockDeneb")
+		}
+
+		versionOpt := func(r *http.Request) {
+			r.Header.Add("Eth-Consensus-Version", version.String(version.Deneb))
+		}
+		rb, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), versionOpt)
+		ep := &ExecPayloadResponseDeneb{}
+		if err := json.Unmarshal(rb, ep); err != nil {
+			return nil, nil, errors.Wrap(err, "error unmarshaling the builder SubmitBlindedBlockDeneb response")
+		}
+		if strings.ToLower(ep.Version) != version.String(version.Deneb) {
+			return nil, nil, errors.New("not a deneb payload")
+		}
+		p, blobBundle, err := ep.ToProto()
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "could not extract proto message from payload")
+		}
+		payload, err := blocks.WrappedExecutionPayloadDeneb(p, 0)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "could not wrap execution payload in interface")
+		}
+		return payload, blobBundle, nil
 	default:
-		return nil, fmt.Errorf("unsupported block version %s", version.String(sb.Version()))
+		return nil, nil, fmt.Errorf("unsupported block version %s", version.String(sb.Version()))
 	}
 }

--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -12,7 +12,9 @@ import (
 	"strconv"
 	"testing"

+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/prysmaticlabs/go-bitfield"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	types "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
@@ -125,7 +127,6 @@ func TestClient_GetHeader(t *testing.T) {
 	var slot types.Slot = 23
 	parentHash := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
 	pubkey := ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
-
 	t.Run("server error", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -236,6 +237,52 @@ func TestClient_GetHeader(t *testing.T) {
 		require.DeepEqual(t, bidValue, value.Bytes())
 		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
 	})
+	t.Run("deneb", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, expectedPath, r.URL.Path)
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponseDeneb)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+		require.NoError(t, err)
+		expectedWithdrawalsRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+		bid, err := h.Message()
+		require.NoError(t, err)
+		bidHeader, err := bid.Header()
+		require.NoError(t, err)
+		withdrawalsRoot, err := bidHeader.WithdrawalsRoot()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(expectedWithdrawalsRoot, withdrawalsRoot))
+		value, err := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
+		require.NoError(t, err)
+		require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", bid.Value()))
+		bidValue := bytesutil.ReverseByteOrder(bid.Value())
+		require.DeepEqual(t, bidValue, value.Bytes())
+		require.DeepEqual(t, big.NewInt(0).SetBytes(bidValue), value.Int)
+		bundle, err := bid.BlindedBlobsBundle()
+		require.NoError(t, err)
+		require.Equal(t, len(bundle.BlobRoots) <= fieldparams.MaxBlobsPerBlock && len(bundle.BlobRoots) > 0, true)
+		for i := range bundle.BlobRoots {
+			require.Equal(t, len(bundle.BlobRoots[i]) == fieldparams.RootLength, true)
+		}
+		require.Equal(t, len(bundle.KzgCommitments) > 0, true)
+		for i := range bundle.KzgCommitments {
+			require.Equal(t, len(bundle.KzgCommitments[i]) == 48, true)
+		}
+		require.Equal(t, len(bundle.Proofs) > 0, true)
+		for i := range bundle.Proofs {
+			require.Equal(t, len(bundle.Proofs[i]) == 48, true)
+		}
+	})
 	t.Run("unsupported version", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -277,7 +324,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		ep, err := c.SubmitBlindedBlock(ctx, sbbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbbb, nil)
 		require.NoError(t, err)
 		require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash()))
 		bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
@@ -303,7 +350,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockCapella(t))
 		require.NoError(t, err)
-		ep, err := c.SubmitBlindedBlock(ctx, sbb)
+		ep, _, err := c.SubmitBlindedBlock(ctx, sbb, nil)
 		require.NoError(t, err)
 		withdrawals, err := ep.Withdrawals()
 		require.NoError(t, err)
@@ -313,6 +360,40 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
+	t.Run("deneb", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "deneb", r.Header.Get("Eth-Consensus-Version"))
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayloadDeneb)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		test := testSignedBlindedBeaconBlockAndBlobsDeneb(t)
+		sbb, err := blocks.NewSignedBeaconBlock(test.Block)
+		require.NoError(t, err)
+
+		ep, blobBundle, err := c.SubmitBlindedBlock(ctx, sbb, test.Blobs)
+		require.NoError(t, err)
+		withdrawals, err := ep.Withdrawals()
+		require.NoError(t, err)
+		require.Equal(t, 1, len(withdrawals))
+		assert.Equal(t, uint64(1), withdrawals[0].Index)
+		assert.Equal(t, types.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
+		assert.Equal(t, uint64(1), withdrawals[0].Amount)
+		require.NotNil(t, blobBundle)
+		require.Equal(t, hexutil.Encode(blobBundle.Blobs[0]), hexutil.Encode(make([]byte, fieldparams.BlobLength)))
+		require.Equal(t, hexutil.Encode(blobBundle.KzgCommitments[0]), "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f")
+		require.Equal(t, hexutil.Encode(blobBundle.Proofs[0]), "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a")
+	})
 	t.Run("mismatched versions, expected bellatrix got capella", func(t *testing.T) {
 		hc := &http.Client{
 			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
@@ -330,13 +411,13 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		}
 		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
 		require.NoError(t, err)
-		_, err = c.SubmitBlindedBlock(ctx, sbbb)
+		_, _, err = c.SubmitBlindedBlock(ctx, sbbb, nil)
 		require.ErrorContains(t, "not a bellatrix payload", err)
 	})
 	t.Run("not blinded", func(t *testing.T) {
 		sbb, err := blocks.NewSignedBeaconBlock(&eth.SignedBeaconBlockBellatrix{Block: &eth.BeaconBlockBellatrix{Body: &eth.BeaconBlockBodyBellatrix{}}})
 		require.NoError(t, err)
-		_, err = (&Client{}).SubmitBlindedBlock(ctx, sbb)
+		_, _, err = (&Client{}).SubmitBlindedBlock(ctx, sbb, nil)
 		require.ErrorIs(t, err, errNotBlinded)
 	})
 }
@@ -626,6 +707,168 @@ func testSignedBlindedBeaconBlockCapella(t *testing.T) *eth.SignedBlindedBeaconB
 	}
 }

+func testSignedBlindedBeaconBlockAndBlobsDeneb(t *testing.T) *eth.SignedBlindedBeaconBlockAndBlobsDeneb {
+	return &eth.SignedBlindedBeaconBlockAndBlobsDeneb{
+		Block: &eth.SignedBlindedBeaconBlockDeneb{
+			Block: &eth.BlindedBeaconBlockDeneb{
+				Slot:          1,
+				ProposerIndex: 1,
+				ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				Body: &eth.BlindedBeaconBlockBodyDeneb{
+					RandaoReveal: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+					Eth1Data: &eth.Eth1Data{
+						DepositRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						DepositCount: 1,
+						BlockHash:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					},
+					Graffiti: ezDecode(t, "0xdeadbeefc0ffee"),
+					ProposerSlashings: []*eth.ProposerSlashing{
+						{
+							Header_1: &eth.SignedBeaconBlockHeader{
+								Header: &eth.BeaconBlockHeader{
+									Slot:          1,
+									ProposerIndex: 1,
+									ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+							},
+							Header_2: &eth.SignedBeaconBlockHeader{
+								Header: &eth.BeaconBlockHeader{
+									Slot:          1,
+									ProposerIndex: 1,
+									ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+							},
+						},
+					},
+					AttesterSlashings: []*eth.AttesterSlashing{
+						{
+							Attestation_1: &eth.IndexedAttestation{
+								AttestingIndices: []uint64{1},
+								Data: &eth.AttestationData{
+									Slot:            1,
+									CommitteeIndex:  1,
+									BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									Source: &eth.Checkpoint{
+										Epoch: 1,
+										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									},
+									Target: &eth.Checkpoint{
+										Epoch: 1,
+										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									},
+								},
+								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+							},
+							Attestation_2: &eth.IndexedAttestation{
+								AttestingIndices: []uint64{1},
+								Data: &eth.AttestationData{
+									Slot:            1,
+									CommitteeIndex:  1,
+									BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									Source: &eth.Checkpoint{
+										Epoch: 1,
+										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									},
+									Target: &eth.Checkpoint{
+										Epoch: 1,
+										Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+									},
+								},
+								Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+							},
+						},
+					},
+					Attestations: []*eth.Attestation{
+						{
+							AggregationBits: bitfield.Bitlist{0x01},
+							Data: &eth.AttestationData{
+								Slot:            1,
+								CommitteeIndex:  1,
+								BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Source: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Target: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+					Deposits: []*eth.Deposit{
+						{
+							Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+							Data: &eth.Deposit_Data{
+								PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+								WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Amount:                1,
+								Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+							},
+						},
+					},
+					VoluntaryExits: []*eth.SignedVoluntaryExit{
+						{
+							Exit: &eth.VoluntaryExit{
+								Epoch:          1,
+								ValidatorIndex: 1,
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+					SyncAggregate: &eth.SyncAggregate{
+						SyncCommitteeSignature: make([]byte, 48),
+						SyncCommitteeBits:      bitfield.Bitvector512{0x01},
+					},
+					ExecutionPayloadHeader: &v1.ExecutionPayloadHeaderDeneb{
+						ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
+						StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+						PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						BlockNumber:      1,
+						GasLimit:         1,
+						GasUsed:          1,
+						Timestamp:        1,
+						ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						BaseFeePerGas:    []byte(strconv.FormatUint(1, 10)),
+						BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						WithdrawalsRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+						DataGasUsed:      1,
+						ExcessDataGas:    1,
+					},
+				},
+			},
+			Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+		},
+		Blobs: []*eth.SignedBlindedBlobSidecar{
+			{
+				Message: &eth.BlindedBlobSidecar{
+					BlockRoot:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					Index:           0,
+					Slot:            1,
+					BlockParentRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					ProposerIndex:   1,
+					BlobRoot:        ezDecode(t, "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"),
+					KzgCommitment:   ezDecode(t, "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"),
+					KzgProof:        ezDecode(t, "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"),
+				},
+				Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+			},
+		},
+	}
+}
+
 func TestRequestLogger(t *testing.T) {
 	wo := WithObserver(&requestLogger{})
 	c, err := NewClient("localhost:3500", wo)
--- a/api/client/builder/testing/BUILD.bazel
+++ b/api/client/builder/testing/BUILD.bazel
@@ -10,6 +10,7 @@ go_library(
        "//consensus-types/interfaces:go_default_library",
        "//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
@@ -7,6 +7,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )

@@ -40,8 +41,8 @@ func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedVali
 }

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

 // Status --
--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
--- a/api/client/builder/types_test.go
+++ b/api/client/builder/types_test.go
@@ -14,6 +14,7 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/golang/protobuf/proto"
 	"github.com/prysmaticlabs/go-bitfield"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
@@ -116,6 +117,47 @@ var testExampleHeaderResponseCapella = `{
  }
 }`

+var testExampleHeaderResponseDeneb = `{
+  "version": "deneb",
+  "data": {
+    "message": {
+      "header": {
+        "parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+        "state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+        "prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "block_number": "1",
+        "gas_limit": "1",
+        "gas_used": "1",
+        "timestamp": "1",
+        "extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
+		"block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "transactions_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "withdrawals_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"data_gas_used": "1",	
+		"excess_data_gas": "1"	
+      },
+      "blinded_blobs_bundle": {
+        "commitments": [
+          "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
+        ],
+        "proofs": [
+          "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
+        ],
+        "blob_roots": [
+          "0x24564723180fcb3d994104538d351c8dcbde12d541676bb736cf678018ca4739"
+        ]
+      },
+      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
+      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
+    },
+    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+  }
+}`
+
 var testExampleHeaderResponseUnknownVersion = `{
  "version": "bad",
  "data": {
@@ -518,6 +560,51 @@ var testExampleExecutionPayloadCapella = `{
  }
 }`

+var testExampleExecutionPayloadDeneb = fmt.Sprintf(`{
+  "version": "deneb",
+  "data": {
+	"execution_payload":{
+		"parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+		"state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+		"prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"block_number": "1",
+		"gas_limit": "1",
+		"gas_used": "1",
+		"timestamp": "1",
+		"extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
+		"block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+		"transactions": [
+		  "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
+		],
+		"withdrawals": [
+		  {
+			"index": "1",
+			"validator_index": "1",
+			"address": "0xcf8e0d4e9587369b2301d0790347320302cc0943",
+			"amount": "1"
+		  }
+		],
+		"data_gas_used": "2",
+ 		"excess_data_gas": "3"
+	  },
+	"blobs_bundle": {
+      "commitments": [
+        "0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f"
+      ],
+      "proofs": [
+        "0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a"
+      ],
+      "blobs": [
+        "%s"
+      ]
+    }
+  }
+}`, hexutil.Encode(make([]byte, fieldparams.BlobLength)))
+
 func TestExecutionPayloadResponseUnmarshal(t *testing.T) {
 	epr := &ExecPayloadResponse{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
@@ -689,6 +776,107 @@ func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	assert.Equal(t, uint64(1), w.Amount.Uint64())
 }

+func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
+	epr := &ExecPayloadResponseDeneb{}
+	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDeneb), epr))
+	cases := []struct {
+		expected string
+		actual   string
+		name     string
+	}{
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ParentHash),
+			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
+		},
+		{
+			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.FeeRecipient),
+			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.StateRoot),
+			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ReceiptsRoot),
+			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
+		},
+		{
+			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.LogsBloom),
+			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.PrevRandao),
+			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BlockNumber),
+			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.GasLimit),
+			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.GasUsed),
+			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.Timestamp),
+			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ExtraData),
+			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
+		},
+		{
+			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BaseFeePerGas),
+			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExecutionPayload.BlockHash),
+			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
+		},
+		{
+			expected: "2",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.DataGasUsed),
+			name:     "ExecPayloadResponse.ExecutionPayload.DataGasUsed",
+		},
+		{
+			expected: "3",
+			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.ExcessDataGas),
+			name:     "ExecPayloadResponse.ExecutionPayload.ExcessDataGas",
+		},
+	}
+	for _, c := range cases {
+		require.Equal(t, c.expected, c.actual, fmt.Sprintf("unexpected value for field %s", c.name))
+	}
+	require.Equal(t, 1, len(epr.Data.ExecutionPayload.Transactions))
+	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
+	require.Equal(t, txHash, hexutil.Encode(epr.Data.ExecutionPayload.Transactions[0]))
+
+	require.Equal(t, 1, len(epr.Data.ExecutionPayload.Withdrawals))
+	w := epr.Data.ExecutionPayload.Withdrawals[0]
+	assert.Equal(t, uint64(1), w.Index.Uint64())
+	assert.Equal(t, uint64(1), w.ValidatorIndex.Uint64())
+	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.Address.String())
+	assert.Equal(t, uint64(1), w.Amount.Uint64())
+	assert.Equal(t, uint64(2), uint64(epr.Data.ExecutionPayload.DataGasUsed))
+	assert.Equal(t, uint64(3), uint64(epr.Data.ExecutionPayload.ExcessDataGas))
+}
+
 func TestExecutionPayloadResponseToProto(t *testing.T) {
 	hr := &ExecPayloadResponse{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), hr))
@@ -796,6 +984,85 @@ func TestExecutionPayloadResponseCapellaToProto(t *testing.T) {

 }

+func TestExecutionPayloadResponseDenebToProto(t *testing.T) {
+	hr := &ExecPayloadResponseDeneb{}
+	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadDeneb), hr))
+	p, blobsBundle, err := hr.ToProto()
+	require.NoError(t, err)
+
+	parentHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	feeRecipient, err := hexutil.Decode("0xabcf8e0d4e9587369b2301d0790347320302cc09")
+	require.NoError(t, err)
+	stateRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	receiptsRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	logsBloom, err := hexutil.Decode("0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000")
+	require.NoError(t, err)
+	prevRandao, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	extraData, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	blockHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+
+	tx, err := hexutil.Decode("0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86")
+	require.NoError(t, err)
+	txList := [][]byte{tx}
+	address, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943")
+	require.NoError(t, err)
+
+	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	require.NoError(t, err)
+	expected := &v1.ExecutionPayloadDeneb{
+		ParentHash:    parentHash,
+		FeeRecipient:  feeRecipient,
+		StateRoot:     stateRoot,
+		ReceiptsRoot:  receiptsRoot,
+		LogsBloom:     logsBloom,
+		PrevRandao:    prevRandao,
+		BlockNumber:   1,
+		GasLimit:      1,
+		GasUsed:       1,
+		Timestamp:     1,
+		ExtraData:     extraData,
+		BaseFeePerGas: bfpg.SSZBytes(),
+		BlockHash:     blockHash,
+		Transactions:  txList,
+		Withdrawals: []*v1.Withdrawal{
+			{
+				Index:          1,
+				ValidatorIndex: 1,
+				Address:        address,
+				Amount:         1,
+			},
+		},
+		DataGasUsed:   2,
+		ExcessDataGas: 3,
+	}
+	require.DeepEqual(t, expected, p)
+	commitment, err := hexutil.Decode("0x8dab030c51e16e84be9caab84ee3d0b8bbec1db4a0e4de76439da8424d9b957370a10a78851f97e4b54d2ce1ab0d686f")
+	require.NoError(t, err)
+	proof, err := hexutil.Decode("0xb4021b0de10f743893d4f71e1bf830c019e832958efd6795baf2f83b8699a9eccc5dc99015d8d4d8ec370d0cc333c06a")
+	require.NoError(t, err)
+
+	expectedBlobs := &v1.BlobsBundle{
+		KzgCommitments: [][]byte{
+			commitment,
+		},
+		Proofs: [][]byte{
+			proof,
+		},
+		Blobs: [][]byte{
+			make([]byte, fieldparams.BlobLength),
+		},
+	}
+
+	require.DeepEqual(t, blobsBundle, expectedBlobs)
+
+}
+
 func pbEth1Data() *eth.Eth1Data {
 	return &eth.Eth1Data{
 		DepositRoot:  make([]byte, 32),
@@ -1026,6 +1293,30 @@ func pbExecutionPayloadHeaderCapella(t *testing.T) *v1.ExecutionPayloadHeaderCap
 	}
 }

+func pbExecutionPayloadHeaderDeneb(t *testing.T) *v1.ExecutionPayloadHeaderDeneb {
+	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	require.NoError(t, err)
+	return &v1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
+		StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+		PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		BlockNumber:      1,
+		GasLimit:         1,
+		GasUsed:          1,
+		Timestamp:        1,
+		ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		BaseFeePerGas:    bfpg.SSZBytes(),
+		BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		WithdrawalsRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		DataGasUsed:      1,
+		ExcessDataGas:    1,
+	}
+}
+
 func TestExecutionPayloadHeader_MarshalJSON(t *testing.T) {
 	h := &ExecutionPayloadHeader{
 		ExecutionPayloadHeader: pbExecutionPayloadHeader(t),
@@ -1046,6 +1337,16 @@ func TestExecutionPayloadHeaderCapella_MarshalJSON(t *testing.T) {
 	require.Equal(t, expected, string(b))
 }

+func TestExecutionPayloadHeaderDeneb_MarshalJSON(t *testing.T) {
+	h := &ExecutionPayloadHeaderDeneb{
+		ExecutionPayloadHeaderDeneb: pbExecutionPayloadHeaderDeneb(t),
+	}
+	b, err := json.Marshal(h)
+	require.NoError(t, err)
+	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","withdrawals_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","data_gas_used":"1","excess_data_gas":"1"}`
+	require.Equal(t, expected, string(b))
+}
+
 var testBuilderBid = `{
    "version":"bellatrix",
 	"data":{
@@ -1156,6 +1457,14 @@ func TestUint256Unmarshal(t *testing.T) {
 	require.Equal(t, expected, string(m))
 }

+func TestUint256Unmarshal_BadData(t *testing.T) {
+	var bigNum Uint256
+
+	assert.ErrorContains(t, "provided Uint256 json string is too short", bigNum.UnmarshalJSON([]byte{'"'}))
+	assert.ErrorContains(t, "provided Uint256 json string is malformed", bigNum.UnmarshalJSON([]byte{'"', '1', '2'}))
+
+}
+
 func TestUint256UnmarshalNegative(t *testing.T) {
 	m := "-1"
 	var value Uint256
--- a/api/client/client.go
+++ b/api/client/client.go
@@ -0,0 +1,97 @@
+package client
+
+import (
+	"context"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+
+	"github.com/pkg/errors"
+)
+
+// Client is a wrapper object around the HTTP client.
+type Client struct {
+	hc      *http.Client
+	baseURL *url.URL
+	token   string
+}
+
+// NewClient constructs a new client with the provided options (ex WithTimeout).
+// `host` is the base host + port used to construct request urls. This value can be
+// a URL string, or NewClient will assume an http endpoint if just `host:port` is used.
+func NewClient(host string, opts ...ClientOpt) (*Client, error) {
+	u, err := urlForHost(host)
+	if err != nil {
+		return nil, err
+	}
+	c := &Client{
+		hc:      &http.Client{},
+		baseURL: u,
+	}
+	for _, o := range opts {
+		o(c)
+	}
+	return c, nil
+}
+
+// Token returns the bearer token used for jwt authentication
+func (c *Client) Token() string {
+	return c.token
+}
+
+// BaseURL returns the base url of the client
+func (c *Client) BaseURL() *url.URL {
+	return c.baseURL
+}
+
+// Do execute the request against the http client
+func (c *Client) Do(req *http.Request) (*http.Response, error) {
+	return c.hc.Do(req)
+}
+
+func urlForHost(h string) (*url.URL, error) {
+	// try to parse as url (being permissive)
+	u, err := url.Parse(h)
+	if err == nil && u.Host != "" {
+		return u, nil
+	}
+	// try to parse as host:port
+	host, port, err := net.SplitHostPort(h)
+	if err != nil {
+		return nil, ErrMalformedHostname
+	}
+	return &url.URL{Host: net.JoinHostPort(host, port), Scheme: "http"}, nil
+}
+
+// NodeURL returns a human-readable string representation of the beacon node base url.
+func (c *Client) NodeURL() string {
+	return c.baseURL.String()
+}
+
+// Get is a generic, opinionated GET function to reduce boilerplate amongst the getters in this package.
+func (c *Client) Get(ctx context.Context, path string, opts ...ReqOption) ([]byte, error) {
+	u := c.baseURL.ResolveReference(&url.URL{Path: path})
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	for _, o := range opts {
+		o(req)
+	}
+	r, err := c.hc.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		err = r.Body.Close()
+	}()
+	if r.StatusCode != http.StatusOK {
+		return nil, Non200Err(r)
+	}
+	b, err := io.ReadAll(r.Body)
+	if err != nil {
+		return nil, errors.Wrap(err, "error reading http response body")
+	}
+	return b, nil
+}
--- a/api/client/client_test.go
+++ b/api/client/client_test.go
@@ -0,0 +1,48 @@
+package client
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func TestValidHostname(t *testing.T) {
+	cases := []struct {
+		name    string
+		hostArg string
+		path    string
+		joined  string
+		err     error
+	}{
+		{
+			name:    "hostname without port",
+			hostArg: "mydomain.org",
+			err:     ErrMalformedHostname,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			cl, err := NewClient(c.hostArg)
+			if c.err != nil {
+				require.ErrorIs(t, err, c.err)
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, c.joined, cl.BaseURL().ResolveReference(&url.URL{Path: c.path}).String())
+		})
+	}
+}
+
+func TestWithAuthenticationToken(t *testing.T) {
+	cl, err := NewClient("https://www.offchainlabs.com:3500", WithAuthenticationToken("my token"))
+	require.NoError(t, err)
+	require.Equal(t, cl.Token(), "my token")
+}
+
+func TestBaseURL(t *testing.T) {
+	cl, err := NewClient("https://www.offchainlabs.com:3500")
+	require.NoError(t, err)
+	require.Equal(t, "www.offchainlabs.com", cl.BaseURL().Hostname())
+	require.Equal(t, "3500", cl.BaseURL().Port())
+}
--- a/api/client/errors.go
+++ b/api/client/errors.go
@@ -0,0 +1,40 @@
+package client
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/pkg/errors"
+)
+
+// ErrMalformedHostname is used to indicate if a host name's format is incorrect.
+var ErrMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
+
+// ErrNotOK is used to indicate when an HTTP request to the 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 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")
+
+// ErrInvalidNodeVersion indicates that the /eth/v1/node/version API response format was not recognized.
+var ErrInvalidNodeVersion = errors.New("invalid node version response")
+
+// Non200Err is a function that parses an HTTP response to handle responses that are not 200 with a formatted error.
+func Non200Err(response *http.Response) error {
+	bodyBytes, err := io.ReadAll(response.Body)
+	var body string
+	if err != nil {
+		body = "(Unable to read response body.)"
+	} else {
+		body = "response body:\n" + string(bodyBytes)
+	}
+	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
+	switch response.StatusCode {
+	case 404:
+		return errors.Wrap(ErrNotFound, msg)
+	default:
+		return errors.Wrap(ErrNotOK, msg)
+	}
+}
--- a/api/client/options.go
+++ b/api/client/options.go
@@ -0,0 +1,48 @@
+package client
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// ReqOption is a request functional option.
+type ReqOption func(*http.Request)
+
+// WithSSZEncoding is a request functional option that adds SSZ encoding header.
+func WithSSZEncoding() ReqOption {
+	return func(req *http.Request) {
+		req.Header.Set("Accept", "application/octet-stream")
+	}
+}
+
+// WithAuthorizationToken is a request functional option that adds header for authorization token.
+func WithAuthorizationToken(token string) ReqOption {
+	return func(req *http.Request) {
+		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+	}
+}
+
+// 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
+	}
+}
+
+// WithRoundTripper replaces the underlying HTTP's transport with a custom one.
+func WithRoundTripper(t http.RoundTripper) ClientOpt {
+	return func(c *Client) {
+		c.hc.Transport = t
+	}
+}
+
+// WithAuthenticationToken sets an oauth token to be used.
+func WithAuthenticationToken(token string) ClientOpt {
+	return func(c *Client) {
+		c.token = token
+	}
+}
--- a/api/client/validator/BUILD.bazel
+++ b/api/client/validator/BUILD.bazel
@@ -0,0 +1,13 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["client.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v4/api/client/validator",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//api/client:go_default_library",
+        "//validator/rpc/apimiddleware:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
+)
--- a/api/client/validator/client.go
+++ b/api/client/validator/client.go
@@ -0,0 +1,121 @@
+package validator
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/api/client"
+	"github.com/prysmaticlabs/prysm/v4/validator/rpc/apimiddleware"
+)
+
+const (
+	localKeysPath    = "/eth/v1/keystores"
+	remoteKeysPath   = "/eth/v1/remotekeys"
+	feeRecipientPath = "/eth/v1/validator/{pubkey}/feerecipient"
+)
+
+// Client provides a collection of helper methods for calling the Keymanager API endpoints.
+type Client struct {
+	*client.Client
+}
+
+// NewClient returns a new Client that includes functions for REST calls to keymanager APIs.
+func NewClient(host string, opts ...client.ClientOpt) (*Client, error) {
+	c, err := client.NewClient(host, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return &Client{c}, nil
+}
+
+// GetValidatorPubKeys gets the current list of web3signer or the local validator public keys in hex format.
+func (c *Client) GetValidatorPubKeys(ctx context.Context) ([]string, error) {
+	jsonlocal, err := c.GetLocalValidatorKeys(ctx)
+	if err != nil {
+		return nil, err
+	}
+	jsonremote, err := c.GetRemoteValidatorKeys(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if len(jsonlocal.Keystores) == 0 && len(jsonremote.Keystores) == 0 {
+		return nil, errors.New("there are no local keys or remote keys on the validator")
+	}
+
+	hexKeys := make(map[string]bool)
+
+	for index := range jsonlocal.Keystores {
+		hexKeys[jsonlocal.Keystores[index].ValidatingPubkey] = true
+	}
+	for index := range jsonremote.Keystores {
+		hexKeys[jsonremote.Keystores[index].Pubkey] = true
+	}
+	keys := make([]string, 0)
+	for k := range hexKeys {
+		keys = append(keys, k)
+	}
+	return keys, nil
+}
+
+// GetLocalValidatorKeys calls the keymanager APIs for local validator keys
+func (c *Client) GetLocalValidatorKeys(ctx context.Context) (*apimiddleware.ListKeystoresResponseJson, error) {
+	localBytes, err := c.Get(ctx, localKeysPath, client.WithAuthorizationToken(c.Token()))
+	if err != nil {
+		return nil, err
+	}
+	jsonlocal := &apimiddleware.ListKeystoresResponseJson{}
+	if err := json.Unmarshal(localBytes, jsonlocal); err != nil {
+		return nil, errors.Wrap(err, "failed to parse local keystore list")
+	}
+	return jsonlocal, nil
+}
+
+// GetRemoteValidatorKeys calls the keymanager APIs for web3signer validator keys
+func (c *Client) GetRemoteValidatorKeys(ctx context.Context) (*apimiddleware.ListRemoteKeysResponseJson, error) {
+	remoteBytes, err := c.Get(ctx, remoteKeysPath, client.WithAuthorizationToken(c.Token()))
+	if err != nil {
+		if !strings.Contains(err.Error(), "Prysm Wallet is not of type Web3Signer") {
+			return nil, err
+		}
+	}
+	jsonremote := &apimiddleware.ListRemoteKeysResponseJson{}
+	if len(remoteBytes) != 0 {
+		if err := json.Unmarshal(remoteBytes, jsonremote); err != nil {
+			return nil, errors.Wrap(err, "failed to parse remote keystore list")
+		}
+	}
+	return jsonremote, nil
+}
+
+// GetFeeRecipientAddresses takes a list of validators in hex format and returns an equal length list of fee recipients in hex format.
+func (c *Client) GetFeeRecipientAddresses(ctx context.Context, validators []string) ([]string, error) {
+	feeRecipients := make([]string, len(validators))
+	for index, validator := range validators {
+		feejson, err := c.GetFeeRecipientAddress(ctx, validator)
+		if err != nil {
+			return nil, errors.Wrap(err, fmt.Sprintf("keymanager API failed to retrieve fee recipient for validator %s", validators[index]))
+		}
+		if feejson.Data == nil {
+			continue
+		}
+		feeRecipients[index] = feejson.Data.Ethaddress
+	}
+	return feeRecipients, nil
+}
+
+// GetFeeRecipientAddress takes a public key and calls the keymanager API to return its fee recipient.
+func (c *Client) GetFeeRecipientAddress(ctx context.Context, pubkey string) (*apimiddleware.GetFeeRecipientByPubkeyResponseJson, error) {
+	path := strings.Replace(feeRecipientPath, "{pubkey}", pubkey, 1)
+	b, err := c.Get(ctx, path, client.WithAuthorizationToken(c.Token()))
+	if err != nil {
+		return nil, err
+	}
+	feejson := &apimiddleware.GetFeeRecipientByPubkeyResponseJson{}
+	if err := json.Unmarshal(b, feejson); err != nil {
+		return nil, errors.Wrap(err, "failed to parse fee recipient")
+	}
+	return feejson, nil
+}
--- a/async/event/feed.go
+++ b/async/event/feed.go
@@ -144,6 +144,7 @@ func (f *Feed) Send(value interface{}) (nsent int) {

 	if !f.typecheck(rvalue.Type()) {
 		f.sendLock <- struct{}{}
+		f.mu.Unlock()
 		panic(feedTypeError{op: "Send", got: rvalue.Type(), want: f.etype})
 	}
 	f.mu.Unlock()
--- a/async/event/feed_test.go
+++ b/async/event/feed_test.go
@@ -32,6 +32,8 @@ func TestFeedPanics(t *testing.T) {
 		f.Send(2)
 		want := feedTypeError{op: "Send", got: reflect.TypeOf(uint64(0)), want: reflect.TypeOf(0)}
 		assert.NoError(t, checkPanic(want, func() { f.Send(uint64(2)) }))
+		// Validate it doesn't deadlock.
+		assert.NoError(t, checkPanic(want, func() { f.Send(uint64(2)) }))
 	}
 	{
 		var f Feed
--- a/beacon-chain/blockchain/chain_info.go
+++ b/beacon-chain/blockchain/chain_info.go
@@ -8,6 +8,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
@@ -339,7 +340,13 @@ func (s *Service) IsOptimistic(_ context.Context) (bool, error) {
 	}
 	s.headLock.RLock()
 	headRoot := s.head.root
+	headSlot := s.head.slot
+	headOptimistic := s.head.optimistic
 	s.headLock.RUnlock()
+	// we trust the head package for recent head slots, otherwise fallback to forkchoice
+	if headSlot+2 >= s.CurrentSlot() {
+		return headOptimistic, nil
+	}

 	s.cfg.ForkChoiceStore.RLock()
 	defer s.cfg.ForkChoiceStore.RUnlock()
@@ -380,6 +387,14 @@ func (s *Service) InForkchoice(root [32]byte) bool {
 	return s.cfg.ForkChoiceStore.HasNode(root)
 }

+// IsViableForkCheckpoint returns whether the given checkpoint is a checkpoint in any
+// chain known to forkchoice
+func (s *Service) IsViableForCheckpoint(cp *forkchoicetypes.Checkpoint) (bool, error) {
+	s.cfg.ForkChoiceStore.RLock()
+	defer s.cfg.ForkChoiceStore.RUnlock()
+	return s.cfg.ForkChoiceStore.IsViableForCheckpoint(cp)
+}
+
 // IsOptimisticForRoot takes the root as argument instead of the current head
 // and returns true if it is optimistic.
 func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool, error) {
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -422,6 +422,12 @@ func TestService_IsOptimistic(t *testing.T) {

 	opt, err := c.IsOptimistic(ctx)
 	require.NoError(t, err)
+	require.Equal(t, primitives.Slot(0), c.CurrentSlot())
+	require.Equal(t, false, opt)
+
+	c.SetGenesisTime(time.Now().Add(-time.Second * time.Duration(4*params.BeaconConfig().SecondsPerSlot)))
+	opt, err = c.IsOptimistic(ctx)
+	require.NoError(t, err)
 	require.Equal(t, true, opt)
 }

--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -25,8 +25,11 @@ var (
 	errWSBlockNotFound = errors.New("weak subjectivity root not found in db")
 	// errWSBlockNotFoundInEpoch is returned when a block is not found in the WS cache or DB within epoch.
 	errWSBlockNotFoundInEpoch = errors.New("weak subjectivity root not found in db within epoch")
-	// errNotDescendantOfFinalized is returned when a block is not a descendant of the finalized checkpoint
+	// ErrNotDescendantOfFinalized is returned when a block is not a descendant of the finalized checkpoint
 	ErrNotDescendantOfFinalized = invalidBlock{error: errors.New("not descendant of finalized checkpoint")}
+	// ErrNotCheckpoint is returned when a given checkpoint is not a
+	// checkpoint in any chain known to forkchoice
+	ErrNotCheckpoint = errors.New("not a checkpoint in forkchoice")
 )

 // An invalid block is the block that fails state transition based on the core protocol rules.
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -154,7 +154,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *notifyForkcho
 		var pId [8]byte
 		copy(pId[:], payloadID[:])
 		s.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(nextSlot, proposerId, pId, arg.headRoot)
-	} else if hasAttr && payloadID == nil {
+	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
 			"slot":      headBlk.Slot(),
@@ -207,7 +207,18 @@ func (s *Service) notifyNewPayload(ctx context.Context, postStateVersion int,
 	if err != nil {
 		return false, errors.Wrap(invalidBlock{error: err}, "could not get execution payload")
 	}
-	lastValidHash, err := s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload)
+
+	var lastValidHash []byte
+	if blk.Version() >= version.Deneb {
+		_, err = blk.Block().Body().BlobKzgCommitments()
+		if err != nil {
+			return false, errors.Wrap(invalidBlock{error: err}, "could not get blob kzg commitments")
+		}
+		// TODO: Convert kzg commitment to version hashes and feed to below
+		lastValidHash, err = s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload, [][32]byte{})
+	} else {
+		lastValidHash, err = s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload, [][32]byte{} /*empty version hashes before Deneb*/)
+	}
 	switch err {
 	case nil:
 		newPayloadValidNodeCount.Inc()
@@ -305,7 +316,7 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,

 	var attr payloadattribute.Attributer
 	switch st.Version() {
-	case version.Capella:
+	case version.Capella, version.Deneb:
 		withdrawals, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
--- a/beacon-chain/blockchain/execution_engine_test.go
+++ b/beacon-chain/blockchain/execution_engine_test.go
@@ -827,6 +827,42 @@ func Test_GetPayloadAttributeV2(t *testing.T) {
 	require.Equal(t, 0, len(a))
 }

+func Test_GetPayloadAttributeDeneb(t *testing.T) {
+	service, tr := minimalTestService(t, WithProposerIdsCache(cache.NewProposerPayloadIDsCache()))
+	ctx := tr.ctx
+
+	st, _ := util.DeterministicGenesisStateDeneb(t, 1)
+	hasPayload, _, vId := service.getPayloadAttribute(ctx, st, 0, []byte{})
+	require.Equal(t, false, hasPayload)
+	require.Equal(t, primitives.ValidatorIndex(0), vId)
+
+	// Cache hit, advance state, no fee recipient
+	suggestedVid := primitives.ValidatorIndex(1)
+	slot := primitives.Slot(1)
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hook := logTest.NewGlobal()
+	hasPayload, attr, vId := service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
+	require.Equal(t, params.BeaconConfig().EthBurnAddressHex, common.BytesToAddress(attr.SuggestedFeeRecipient()).String())
+	require.LogsContain(t, hook, "Fee recipient is currently using the burn address")
+	a, err := attr.Withdrawals()
+	require.NoError(t, err)
+	require.Equal(t, 0, len(a))
+
+	// Cache hit, advance state, has fee recipient
+	suggestedAddr := common.HexToAddress("123")
+	require.NoError(t, service.cfg.BeaconDB.SaveFeeRecipientsByValidatorIDs(ctx, []primitives.ValidatorIndex{suggestedVid}, []common.Address{suggestedAddr}))
+	service.cfg.ProposerSlotIndexCache.SetProposerAndPayloadIDs(slot, suggestedVid, [8]byte{}, [32]byte{})
+	hasPayload, attr, vId = service.getPayloadAttribute(ctx, st, slot, params.BeaconConfig().ZeroHash[:])
+	require.Equal(t, true, hasPayload)
+	require.Equal(t, suggestedVid, vId)
+	require.Equal(t, suggestedAddr, common.BytesToAddress(attr.SuggestedFeeRecipient()))
+	a, err = attr.Withdrawals()
+	require.NoError(t, err)
+	require.Equal(t, 0, len(a))
+}
+
 func Test_UpdateLastValidatedCheckpoint(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	params.OverrideBeaconConfig(params.MainnetConfig())
--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -47,9 +47,11 @@ func (s *Service) UpdateAndSaveHeadWithBalances(ctx context.Context) error {

 // This defines the current chain service's view of head.
 type head struct {
-	root  [32]byte                             // current head root.
-	block interfaces.ReadOnlySignedBeaconBlock // current head block.
-	state state.BeaconState                    // current head state.
+	root       [32]byte                             // current head root.
+	block      interfaces.ReadOnlySignedBeaconBlock // current head block.
+	state      state.BeaconState                    // current head state.
+	slot       primitives.Slot                      // the head block slot number
+	optimistic bool                                 // optimistic status when saved head
 }

 // This saves head info to the local service cache, it also saves the
@@ -94,6 +96,10 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 		return errors.Wrap(err, "could not get old head root")
 	}
 	oldHeadRoot := bytesutil.ToBytes32(r)
+	isOptimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(newHeadRoot)
+	if err != nil {
+		log.WithError(err).Error("could not check if node is optimistically synced")
+	}
 	if headBlock.Block().ParentRoot() != oldHeadRoot {
 		// A chain re-org occurred, so we fire an event notifying the rest of the services.
 		commonRoot, forkSlot, err := s.cfg.ForkChoiceStore.CommonAncestor(ctx, oldHeadRoot, newHeadRoot)
@@ -125,10 +131,6 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 		reorgDistance.Observe(float64(dis))
 		reorgDepth.Observe(float64(dep))

-		isOptimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(newHeadRoot)
-		if err != nil {
-			return errors.Wrap(err, "could not check if node is optimistically synced")
-		}
 		s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 			Type: statefeed.Reorg,
 			Data: &ethpbv1.EventChainReorg{
@@ -150,7 +152,14 @@ func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock
 	}

 	// Cache the new head info.
-	if err := s.setHead(newHeadRoot, headBlock, headState); err != nil {
+	newHead := &head{
+		root:       newHeadRoot,
+		block:      headBlock,
+		state:      headState,
+		optimistic: isOptimistic,
+		slot:       headBlock.Block().Slot(),
+	}
+	if err := s.setHead(newHead); err != nil {
 		return errors.Wrap(err, "could not set head")
 	}

@@ -195,20 +204,22 @@ func (s *Service) saveHeadNoDB(ctx context.Context, b interfaces.ReadOnlySignedB
 	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.ReadOnlySignedBeaconBlock, state state.BeaconState) error {
+// This sets head view object which is used to track the head slot, root, block, state and optimistic status
+func (s *Service) setHead(newHead *head) error {
 	s.headLock.Lock()
 	defer s.headLock.Unlock()

 	// This does a full copy of the block and state.
-	bCp, err := block.Copy()
+	bCp, err := newHead.block.Copy()
 	if err != nil {
 		return err
 	}
 	s.head = &head{
-		root:  root,
-		block: bCp,
-		state: state.Copy(),
+		root:       newHead.root,
+		block:      bCp,
+		state:      newHead.state.Copy(),
+		optimistic: newHead.optimistic,
+		slot:       newHead.slot,
 	}
 	return nil
 }
--- a/beacon-chain/blockchain/head_sync_committee_info.go
+++ b/beacon-chain/blockchain/head_sync_committee_info.go
@@ -53,7 +53,7 @@ func (s *Service) HeadSyncContributionProofDomain(ctx context.Context, slot prim

 // HeadSyncCommitteeIndices returns the sync committee index position using the head state. Input `slot` is taken in consideration
 // where validator's duty for `slot - 1` is used for block inclusion in `slot`. That means when a validator is at epoch boundary
-// across EPOCHS_PER_SYNC_COMMITTEE_PERIOD then the valiator will be considered using next period sync committee.
+// across EPOCHS_PER_SYNC_COMMITTEE_PERIOD then the validator will be considered using next period sync committee.
 //
 // Spec definition:
 // Being assigned to a sync committee for a given slot means that the validator produces and broadcasts signatures for slot - 1 for inclusion in slot.
@@ -157,7 +157,11 @@ func (s *Service) getSyncCommitteeHeadState(ctx context.Context, slot primitives
 		if headState == nil || headState.IsNil() {
 			return nil, errors.New("nil state")
 		}
-		headState, err = transition.ProcessSlotsIfPossible(ctx, headState, slot)
+		headRoot, err := s.HeadRoot(ctx)
+		if err != nil {
+			return nil, err
+		}
+		headState, err = transition.ProcessSlotsUsingNextSlotCache(ctx, headState, headRoot, slot)
 		if err != nil {
 			return nil, err
 		}
--- a/beacon-chain/blockchain/head_sync_committee_info_test.go
+++ b/beacon-chain/blockchain/head_sync_committee_info_test.go
@@ -6,6 +6,7 @@ import (

 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/signing"
+	dbTest "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
@@ -15,7 +16,7 @@ import (

 func TestService_HeadSyncCommitteeIndices(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
 	c.head = &head{state: s}

 	// Current period
@@ -38,7 +39,7 @@ func TestService_HeadSyncCommitteeIndices(t *testing.T) {

 func TestService_headCurrentSyncCommitteeIndices(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
 	c.head = &head{state: s}

 	// Process slot up to `EpochsPerSyncCommitteePeriod` so it can `ProcessSyncCommitteeUpdates`.
@@ -66,7 +67,7 @@ func TestService_headNextSyncCommitteeIndices(t *testing.T) {

 func TestService_HeadSyncCommitteePubKeys(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
 	c.head = &head{state: s}

 	// Process slot up to 2 * `EpochsPerSyncCommitteePeriod` so it can run `ProcessSyncCommitteeUpdates` twice.
@@ -81,7 +82,7 @@ func TestService_HeadSyncCommitteePubKeys(t *testing.T) {

 func TestService_HeadSyncCommitteeDomain(t *testing.T) {
 	s, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().TargetCommitteeSize)
-	c := &Service{}
+	c := &Service{cfg: &config{BeaconDB: dbTest.SetupDB(t)}}
 	c.head = &head{state: s}

 	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommittee, s.GenesisValidatorsRoot())
--- a/beacon-chain/blockchain/log.go
+++ b/beacon-chain/blockchain/log.go
@@ -53,7 +53,7 @@ func logStateTransitionData(b interfaces.ReadOnlyBeaconBlock) error {
 		log = log.WithField("payloadHash", fmt.Sprintf("%#x", bytesutil.Trunc(p.BlockHash())))
 		txs, err := p.Transactions()
 		switch {
-		case errors.Is(err, consensus_types.ErrUnsupportedGetter):
+		case errors.Is(err, consensus_types.ErrUnsupportedField):
 		case err != nil:
 			return err
 		default:
@@ -120,7 +120,7 @@ func logPayload(block interfaces.ReadOnlyBeaconBlock) error {
 	fields := logrus.Fields{
 		"blockHash":   fmt.Sprintf("%#x", bytesutil.Trunc(payload.BlockHash())),
 		"parentHash":  fmt.Sprintf("%#x", bytesutil.Trunc(payload.ParentHash())),
-		"blockNumber": payload.BlockNumber,
+		"blockNumber": payload.BlockNumber(),
 		"gasUtilized": fmt.Sprintf("%.2f", gasUtilized),
 	}
 	if block.Version() >= version.Capella {
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -172,3 +172,10 @@ func WithClockSynchronizer(gs *startup.ClockSynchronizer) Option {
 		return nil
 	}
 }
+
+func WithSyncComplete(c chan struct{}) Option {
+	return func(s *Service) error {
+		s.syncComplete = c
+		return nil
+	}
+}
--- a/beacon-chain/blockchain/process_attestation_helpers.go
+++ b/beacon-chain/blockchain/process_attestation_helpers.go
@@ -8,6 +8,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/async"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
@@ -18,7 +19,17 @@ import (
 )

 // getAttPreState retrieves the att pre state by either from the cache or the DB.
-func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (state.BeaconState, error) {
+func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error) {
+	// If the attestation is recent and canonical we can use the head state to compute the shuffling.
+	headEpoch := slots.ToEpoch(s.HeadSlot())
+	if c.Epoch == headEpoch {
+		targetSlot, err := s.cfg.ForkChoiceStore.Slot([32]byte(c.Root))
+		if err == nil && slots.ToEpoch(targetSlot)+1 >= headEpoch {
+			if s.cfg.ForkChoiceStore.IsCanonical([32]byte(c.Root)) {
+				return s.HeadStateReadOnly(ctx)
+			}
+		}
+	}
 	// Use a multilock to allow scoped holding of a mutex by a checkpoint root + epoch
 	// allowing us to behave smarter in terms of how this function is used concurrently.
 	epochKey := strconv.FormatUint(uint64(c.Epoch), 10 /* base 10 */)
@@ -32,7 +43,36 @@ func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (stat
 	if cachedState != nil && !cachedState.IsNil() {
 		return cachedState, nil
 	}
+	// Try the next slot cache for the early epoch calls, this should mostly have been covered already
+	// but is cheap
+	slot, err := slots.EpochStart(c.Epoch)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not compute epoch start")
+	}
+	cachedState = transition.NextSlotState(c.Root, slot)
+	if cachedState != nil && !cachedState.IsNil() {
+		if cachedState.Slot() != slot {
+			cachedState, err = transition.ProcessSlots(ctx, cachedState, slot)
+			if err != nil {
+				return nil, errors.Wrap(err, "could not process slots")
+			}
+		}
+		if err := s.checkpointStateCache.AddCheckpointState(c, cachedState); err != nil {
+			return nil, errors.Wrap(err, "could not save checkpoint state to cache")
+		}
+		return cachedState, nil
+	}

+	// Do not process attestations for old non viable checkpoints otherwise
+	ok, err := s.cfg.ForkChoiceStore.IsViableForCheckpoint(&forkchoicetypes.Checkpoint{Root: [32]byte(c.Root), Epoch: c.Epoch})
+	if err != nil {
+		return nil, errors.Wrap(err, "could not check checkpoint condition in forkchoice")
+	}
+	if !ok {
+		return nil, errors.Wrap(ErrNotCheckpoint, fmt.Sprintf("epoch %d root %#x", c.Epoch, c.Root))
+	}
+
+	// Fallback to state regeneration.
 	baseState, err := s.cfg.StateGen.StateByRoot(ctx, bytesutil.ToBytes32(c.Root))
 	if err != nil {
 		return nil, errors.Wrapf(err, "could not get pre state for epoch %d", c.Epoch)
--- a/beacon-chain/blockchain/process_attestation_test.go
+++ b/beacon-chain/blockchain/process_attestation_test.go
@@ -27,11 +27,20 @@ func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
 	blkWithoutState := util.NewBeaconBlock()
 	blkWithoutState.Block.Slot = 0
 	util.SaveBlock(t, ctx, beaconDB, blkWithoutState)
-	BlkWithOutStateRoot, err := blkWithoutState.Block.HashTreeRoot()
+
+	cp := &ethpb.Checkpoint{}
+	st, blkRoot, err := prepareForkchoiceState(ctx, 0, [32]byte{}, [32]byte{}, params.BeaconConfig().ZeroHash, cp, cp)
 	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))

 	blkWithStateBadAtt := util.NewBeaconBlock()
 	blkWithStateBadAtt.Block.Slot = 1
+	r, err := blkWithStateBadAtt.Block.HashTreeRoot()
+	require.NoError(t, err)
+	cp = &ethpb.Checkpoint{Root: r[:]}
+	st, blkRoot, err = prepareForkchoiceState(ctx, blkWithStateBadAtt.Block.Slot, r, [32]byte{}, params.BeaconConfig().ZeroHash, cp, cp)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
 	util.SaveBlock(t, ctx, beaconDB, blkWithStateBadAtt)
 	BlkWithStateBadAttRoot, err := blkWithStateBadAtt.Block.HashTreeRoot()
 	require.NoError(t, err)
@@ -42,7 +51,7 @@ func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, BlkWithStateBadAttRoot))

 	blkWithValidState := util.NewBeaconBlock()
-	blkWithValidState.Block.Slot = 2
+	blkWithValidState.Block.Slot = 32
 	util.SaveBlock(t, ctx, beaconDB, blkWithValidState)

 	blkWithValidStateRoot, err := blkWithValidState.Block.HashTreeRoot()
@@ -57,6 +66,10 @@ func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, blkWithValidStateRoot))

+	service.head = &head{
+		state: st,
+	}
+
 	tests := []struct {
 		name      string
 		a         *ethpb.Attestation
@@ -67,11 +80,6 @@ func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
 			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,
@@ -160,6 +168,9 @@ func TestStore_SaveCheckpointState(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, bytesutil.ToBytes32([]byte{'A'})))
 	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{Root: bytesutil.PadTo([]byte{'A'}, fieldparams.RootLength)}))

+	st, root, err := prepareForkchoiceState(ctx, 1, [32]byte(cp1.Root), [32]byte{}, [32]byte{'R'}, cp1, cp1)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
 	s1, err := service.getAttPreState(ctx, cp1)
 	require.NoError(t, err)
 	assert.Equal(t, 1*params.BeaconConfig().SlotsPerEpoch, s1.Slot(), "Unexpected state slot")
@@ -167,8 +178,17 @@ func TestStore_SaveCheckpointState(t *testing.T) {
 	cp2 := &ethpb.Checkpoint{Epoch: 2, Root: bytesutil.PadTo([]byte{'B'}, fieldparams.RootLength)}
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, bytesutil.ToBytes32([]byte{'B'})))
 	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{Root: bytesutil.PadTo([]byte{'B'}, fieldparams.RootLength)}))
+
 	s2, err := service.getAttPreState(ctx, cp2)
+	require.ErrorContains(t, "epoch 2 root 0x4200000000000000000000000000000000000000000000000000000000000000: not a checkpoint in forkchoice", err)
+
+	st, root, err = prepareForkchoiceState(ctx, 33, [32]byte(cp2.Root), [32]byte(cp1.Root), [32]byte{'R'}, cp2, cp2)
 	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+
+	s2, err = service.getAttPreState(ctx, cp2)
+	require.NoError(t, err)
+
 	assert.Equal(t, 2*params.BeaconConfig().SlotsPerEpoch, s2.Slot(), "Unexpected state slot")

 	s1, err = service.getAttPreState(ctx, cp1)
@@ -187,6 +207,10 @@ func TestStore_SaveCheckpointState(t *testing.T) {
 	cp3 := &ethpb.Checkpoint{Epoch: 1, Root: bytesutil.PadTo([]byte{'C'}, fieldparams.RootLength)}
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, s, bytesutil.ToBytes32([]byte{'C'})))
 	require.NoError(t, service.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{Root: bytesutil.PadTo([]byte{'C'}, fieldparams.RootLength)}))
+	st, root, err = prepareForkchoiceState(ctx, 31, [32]byte(cp3.Root), [32]byte(cp2.Root), [32]byte{'P'}, cp2, cp2)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+
 	s3, err := service.getAttPreState(ctx, cp3)
 	require.NoError(t, err)
 	assert.Equal(t, s.Slot(), s3.Slot(), "Unexpected state slot")
@@ -195,11 +219,18 @@ func TestStore_SaveCheckpointState(t *testing.T) {
 func TestStore_UpdateCheckpointState(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx := tr.ctx
+	baseState, _ := util.DeterministicGenesisState(t, 1)

 	epoch := primitives.Epoch(1)
-	baseState, _ := util.DeterministicGenesisState(t, 1)
-	checkpoint := &ethpb.Checkpoint{Epoch: epoch, Root: bytesutil.PadTo([]byte("hi"), fieldparams.RootLength)}
+	blk := util.NewBeaconBlock()
+	r1, err := blk.Block.HashTreeRoot()
+	require.NoError(t, err)
+	checkpoint := &ethpb.Checkpoint{Epoch: epoch, Root: r1[:]}
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, baseState, bytesutil.ToBytes32(checkpoint.Root)))
+	st, blkRoot, err := prepareForkchoiceState(ctx, blk.Block.Slot, r1, [32]byte{}, params.BeaconConfig().ZeroHash, checkpoint, checkpoint)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, r1))
 	returned, err := service.getAttPreState(ctx, checkpoint)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().SlotsPerEpoch.Mul(uint64(checkpoint.Epoch)), returned.Slot(), "Incorrectly returned base state")
@@ -209,8 +240,16 @@ func TestStore_UpdateCheckpointState(t *testing.T) {
 	assert.Equal(t, returned.Slot(), cached.Slot(), "State should have been cached")

 	epoch = 2
-	newCheckpoint := &ethpb.Checkpoint{Epoch: epoch, Root: bytesutil.PadTo([]byte("bye"), fieldparams.RootLength)}
+	blk = util.NewBeaconBlock()
+	blk.Block.Slot = 64
+	r2, err := blk.Block.HashTreeRoot()
+	require.NoError(t, err)
+	newCheckpoint := &ethpb.Checkpoint{Epoch: epoch, Root: r2[:]}
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, baseState, bytesutil.ToBytes32(newCheckpoint.Root)))
+	st, blkRoot, err = prepareForkchoiceState(ctx, blk.Block.Slot, r2, r1, params.BeaconConfig().ZeroHash, newCheckpoint, newCheckpoint)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, r2))
 	returned, err = service.getAttPreState(ctx, newCheckpoint)
 	require.NoError(t, err)
 	s, err := slots.EpochStart(newCheckpoint.Epoch)
@@ -289,3 +328,22 @@ func TestVerifyBeaconBlock_OK(t *testing.T) {

 	assert.NoError(t, service.verifyBeaconBlock(ctx, d), "Did not receive the wanted error")
 }
+
+func TestGetAttPreState_HeadState(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx := tr.ctx
+	baseState, _ := util.DeterministicGenesisState(t, 1)
+
+	epoch := primitives.Epoch(1)
+	blk := util.NewBeaconBlock()
+	r1, err := blk.Block.HashTreeRoot()
+	require.NoError(t, err)
+	checkpoint := &ethpb.Checkpoint{Epoch: epoch, Root: r1[:]}
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, baseState, bytesutil.ToBytes32(checkpoint.Root)))
+	require.NoError(t, transition.UpdateNextSlotCache(ctx, checkpoint.Root, baseState))
+	_, err = service.getAttPreState(ctx, checkpoint)
+	require.NoError(t, err)
+	st, err := service.checkpointStateCache.StateByCheckpoint(checkpoint)
+	require.NoError(t, err)
+	require.Equal(t, params.BeaconConfig().SlotsPerEpoch, st.Slot())
+}
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -136,7 +136,7 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.ReadOnlySignedB
 	if err != nil {
 		return errors.Wrap(err, "could not validate new payload")
 	}
-	if isValidPayload {
+	if signed.Version() < version.Capella && isValidPayload {
 		if err := s.validateMergeTransitionBlock(ctx, preStateVersion, preStateHeader, signed); err != nil {
 			return err
 		}
@@ -145,8 +145,7 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.ReadOnlySignedB
 	if err := s.savePostStateInfo(ctx, blockRoot, signed, postState); err != nil {
 		return err
 	}
-
-	if err := s.insertBlockToForkchoiceStore(ctx, signed.Block(), blockRoot, postState); err != nil {
+	if err := s.cfg.ForkChoiceStore.InsertNode(ctx, postState, blockRoot); err != nil {
 		return errors.Wrapf(err, "could not insert block %d to fork choice store", signed.Block().Slot())
 	}
 	if err := s.handleBlockAttestations(ctx, signed.Block(), postState); err != nil {
@@ -186,7 +185,6 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.ReadOnlySignedB
 			}
 		}()
 	}
-
 	justified := s.cfg.ForkChoiceStore.JustifiedCheckpoint()
 	start := time.Now()
 	headRoot, err := s.cfg.ForkChoiceStore.Head(ctx)
@@ -257,10 +255,6 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.ReadOnlySignedB
 		if err := s.updateFinalized(ctx, &ethpb.Checkpoint{Epoch: finalized.Epoch, Root: finalized.Root[:]}); err != nil {
 			return err
 		}
-		isOptimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(finalized.Root)
-		if err != nil {
-			return errors.Wrap(err, "could not check if node is optimistically synced")
-		}
 		go func() {
 			// Send an event regarding the new finalized checkpoint over a common event feed.
 			stateRoot := signed.Block().StateRoot()
@@ -270,7 +264,7 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.ReadOnlySignedB
 					Epoch:               postState.FinalizedCheckpoint().Epoch,
 					Block:               postState.FinalizedCheckpoint().Root,
 					State:               stateRoot[:],
-					ExecutionOptimistic: isOptimistic,
+					ExecutionOptimistic: isValidPayload,
 				},
 			})

@@ -285,7 +279,7 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.ReadOnlySignedB
 		}()
 	}
 	defer reportAttestationInclusion(b)
-	if err := s.handleEpochBoundary(ctx, postState); err != nil {
+	if err := s.handleEpochBoundary(ctx, postState, blockRoot[:]); err != nil {
 		return err
 	}
 	onBlockProcessingTime.Observe(float64(time.Since(startTime).Milliseconds()))
@@ -483,14 +477,14 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySi
 }

 // Epoch boundary bookkeeping such as logging epoch summaries.
-func (s *Service) handleEpochBoundary(ctx context.Context, postState state.BeaconState) error {
+func (s *Service) handleEpochBoundary(ctx context.Context, postState state.BeaconState, blockRoot []byte) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.handleEpochBoundary")
 	defer span.End()

 	var err error
 	if postState.Slot()+1 == s.nextEpochBoundarySlot {
 		copied := postState.Copy()
-		copied, err := transition.ProcessSlots(ctx, copied, copied.Slot()+1)
+		copied, err := transition.ProcessSlotsUsingNextSlotCache(ctx, copied, blockRoot, copied.Slot()+1)
 		if err != nil {
 			return err
 		}
@@ -528,23 +522,6 @@ 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
-// to gain information on the most current chain.
-func (s *Service) insertBlockToForkchoiceStore(ctx context.Context, blk interfaces.ReadOnlyBeaconBlock, root [32]byte, st state.BeaconState) error {
-	ctx, span := trace.StartSpan(ctx, "blockChain.insertBlockToForkchoiceStore")
-	defer span.End()
-
-	if !s.cfg.ForkChoiceStore.HasNode(blk.ParentRoot()) {
-		fCheckpoint := st.FinalizedCheckpoint()
-		jCheckpoint := st.CurrentJustifiedCheckpoint()
-		if err := s.fillInForkChoiceMissingBlocks(ctx, blk, fCheckpoint, jCheckpoint); err != nil {
-			return err
-		}
-	}
-
-	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.ReadOnlyBeaconBlock, st state.BeaconState) error {
@@ -651,26 +628,23 @@ func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion

 // This routine checks if there is a cached proposer payload ID available for the next slot proposer.
 // If there is not, it will call forkchoice updated with the correct payload attribute then cache the payload ID.
-func (s *Service) spawnLateBlockTasksLoop() {
-	go func() {
-		_, err := s.clockWaiter.WaitForClock(s.ctx)
-		if err != nil {
-			log.WithError(err).Error("spawnLateBlockTasksLoop encountered an error waiting for initialization")
+func (s *Service) runLateBlockTasks() {
+	if err := s.waitForSync(); err != nil {
+		log.WithError(err).Error("failed to wait for initial sync")
+		return
+	}
+
+	attThreshold := params.BeaconConfig().SecondsPerSlot / 3
+	ticker := slots.NewSlotTickerWithOffset(s.genesisTime, time.Duration(attThreshold)*time.Second, params.BeaconConfig().SecondsPerSlot)
+	for {
+		select {
+		case <-ticker.C():
+			s.lateBlockTasks(s.ctx)
+		case <-s.ctx.Done():
+			log.Debug("Context closed, exiting routine")
 			return
 		}
-		attThreshold := params.BeaconConfig().SecondsPerSlot / 3
-		ticker := slots.NewSlotTickerWithOffset(s.genesisTime, time.Duration(attThreshold)*time.Second, params.BeaconConfig().SecondsPerSlot)
-		for {
-			select {
-			case <-ticker.C():
-				s.lateBlockTasks(s.ctx)
-
-			case <-s.ctx.Done():
-				log.Debug("Context closed, exiting routine")
-				return
-			}
-		}
-	}()
+	}
 }

 // lateBlockTasks  is called 4 seconds into the slot and performs tasks
@@ -685,12 +659,26 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 		Type: statefeed.MissedSlot,
 	})

+	headRoot := s.headRoot()
+	headState := s.headState(ctx)
+	lastRoot, lastState := transition.LastCachedState()
+	if lastState == nil {
+		lastRoot, lastState = headRoot[:], headState
+	}
+	// Copy all the field tries in our cached state in the event of late
+	// blocks.
+	lastState.CopyAllTries()
+	if err := transition.UpdateNextSlotCache(ctx, lastRoot, lastState); err != nil {
+		log.WithError(err).Debug("could not update next slot state cache")
+	}
+
 	// Head root should be empty when retrieving proposer index for the next slot.
 	_, id, has := s.cfg.ProposerSlotIndexCache.GetProposerPayloadIDs(s.CurrentSlot()+1, [32]byte{} /* head root */)
 	// There exists proposer for next slot, but we haven't called fcu w/ payload attribute yet.
 	if (!has && !features.Get().PrepareAllPayloads) || id != [8]byte{} {
 		return
 	}
+
 	s.headLock.RLock()
 	headBlock, err := s.headBlock()
 	if err != nil {
@@ -698,8 +686,6 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 		log.WithError(err).Debug("could not perform late block tasks: failed to retrieve head block")
 		return
 	}
-	headRoot := s.headRoot()
-	headState := s.headState(ctx)
 	s.headLock.RUnlock()
 	_, err = s.notifyForkchoiceUpdate(ctx, &notifyForkchoiceUpdateArg{
 		headState: headState,
@@ -709,11 +695,14 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	if err != nil {
 		log.WithError(err).Debug("could not perform late block tasks: failed to update forkchoice with engine")
 	}
-	lastRoot, lastState := transition.LastCachedState()
-	if lastState == nil {
-		lastRoot, lastState = headRoot[:], headState
-	}
-	if err = transition.UpdateNextSlotCache(ctx, lastRoot, lastState); err != nil {
-		log.WithError(err).Debug("could not update next slot state cache")
+}
+
+// waitForSync blocks until the node is synced to the head.
+func (s *Service) waitForSync() error {
+	select {
+	case <-s.syncComplete:
+		return nil
+	case <-s.ctx.Done():
+		return errors.New("context closed, exiting goroutine")
 	}
 }
--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
@@ -636,7 +636,7 @@ func TestHandleEpochBoundary_UpdateFirstSlot(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 1024)
 	service.head = &head{state: s}
 	require.NoError(t, s.SetSlot(2*params.BeaconConfig().SlotsPerEpoch))
-	require.NoError(t, service.handleEpochBoundary(ctx, s))
+	require.NoError(t, service.handleEpochBoundary(ctx, s, []byte{}))
 	require.Equal(t, 3*params.BeaconConfig().SlotsPerEpoch, service.nextEpochBoundarySlot)
 }

@@ -1875,9 +1875,9 @@ func TestOnBlock_HandleBlockAttestations(t *testing.T) {
 	r3 := bytesutil.ToBytes32(a3.Data.BeaconBlockRoot)
 	require.Equal(t, false, service.cfg.ForkChoiceStore.HasNode(r3))

-	require.NoError(t, service.handleBlockAttestations(ctx, wsb.Block(), st)) // fine to use the same committe as st
+	require.NoError(t, service.handleBlockAttestations(ctx, wsb.Block(), st)) // fine to use the same committee as st
 	require.Equal(t, 0, service.cfg.AttPool.ForkchoiceAttestationCount())
-	require.NoError(t, service.handleBlockAttestations(ctx, wsb3.Block(), st3)) // fine to use the same committe as st
+	require.NoError(t, service.handleBlockAttestations(ctx, wsb3.Block(), st3)) // fine to use the same committee as st
 	require.Equal(t, 1, len(service.cfg.AttPool.BlockAttestations()))
 }

--- a/beacon-chain/blockchain/receive_attestation.go
+++ b/beacon-chain/blockchain/receive_attestation.go
@@ -26,7 +26,7 @@ const reorgLateBlockCountAttestations = 2 * time.Second
 // AttestationStateFetcher allows for retrieving a beacon state corresponding to the block
 // root of an attestation's target checkpoint.
 type AttestationStateFetcher interface {
-	AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.BeaconState, error)
+	AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error)
 }

 // AttestationReceiver interface defines the methods of chain service receive and processing new attestations.
@@ -37,7 +37,7 @@ type AttestationReceiver interface {
 }

 // AttestationTargetState returns the pre state of attestation.
-func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.BeaconState, error) {
+func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error) {
 	ss, err := slots.EpochStart(target.Epoch)
 	if err != nil {
 		return nil, err
@@ -45,6 +45,9 @@ func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Chec
 	if err := slots.ValidateClock(ss, uint64(s.genesisTime.Unix())); err != nil {
 		return nil, err
 	}
+	// We acquire the lock here instead than on gettAttPreState because that function gets called from UpdateHead that holds a write lock
+	s.cfg.ForkChoiceStore.RLock()
+	defer s.cfg.ForkChoiceStore.RUnlock()
 	return s.getAttPreState(ctx, target)
 }

--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -26,6 +26,7 @@ type BlockReceiver interface {
 	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error
 	ReceiveBlockBatch(ctx context.Context, blocks []interfaces.ReadOnlySignedBeaconBlock, blkRoots [][32]byte) error
 	HasBlock(ctx context.Context, root [32]byte) bool
+	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 }

 // SlashingReceiver interface defines the methods of chain service for receiving validated slashing over the wire.
@@ -150,6 +151,11 @@ func (s *Service) HasBlock(ctx context.Context, root [32]byte) bool {
 	return s.hasBlockInInitSyncOrDB(ctx, root)
 }

+// RecentBlockSlot returns block slot form fork choice store
+func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
+	return s.cfg.ForkChoiceStore.Slot(root)
+}
+
 // ReceiveAttesterSlashing receives an attester slashing and inserts it to forkchoice
 func (s *Service) ReceiveAttesterSlashing(ctx context.Context, slashing *ethpb.AttesterSlashing) {
 	s.cfg.ForkChoiceStore.Lock()
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -60,6 +60,7 @@ type Service struct {
 	wsVerifier            *WeakSubjectivityVerifier
 	clockSetter           startup.ClockSetter
 	clockWaiter           startup.ClockWaiter
+	syncComplete          chan struct{}
 }

 // config options for the service.
@@ -130,7 +131,7 @@ func (s *Service) Start() {
 		}
 	}
 	s.spawnProcessAttestationsRoutine()
-	s.spawnLateBlockTasksLoop()
+	go s.runLateBlockTasks()
 }

 // Stop the blockchain service's main event loop and associated goroutines.
@@ -307,7 +308,13 @@ 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 {
+	if err := s.setHead(&head{
+		finalizedRoot,
+		finalizedBlock,
+		finalizedState,
+		finalizedBlock.Block().Slot(),
+		false,
+	}); err != nil {
 		return errors.Wrap(err, "could not set head")
 	}

@@ -439,7 +446,13 @@ 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 {
+	if err := s.setHead(&head{
+		genesisBlkRoot,
+		genesisBlk,
+		genesisState,
+		genesisBlk.Block().Slot(),
+		false,
+	}); err != nil {
 		log.WithError(err).Fatal("Could not set head")
 	}
 	return nil
--- a/beacon-chain/blockchain/service_test.go
+++ b/beacon-chain/blockchain/service_test.go
@@ -377,9 +377,7 @@ func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
 	require.NoError(t, err)
 	beaconState, err := util.NewBeaconState()
 	require.NoError(t, err)
-	wsb, err := consensusblocks.NewSignedBeaconBlock(b)
-	require.NoError(t, err)
-	require.NoError(t, s.insertBlockToForkchoiceStore(ctx, wsb.Block(), r, beaconState))
+	require.NoError(t, s.cfg.ForkChoiceStore.InsertNode(ctx, beaconState, r))

 	assert.Equal(t, false, s.hasBlock(ctx, [32]byte{}), "Should not have block")
 	assert.Equal(t, true, s.hasBlock(ctx, r), "Should have block")
@@ -453,9 +451,7 @@ func BenchmarkHasBlockForkChoiceStore_DoublyLinkedTree(b *testing.B) {
 	bs := &ethpb.BeaconState{FinalizedCheckpoint: &ethpb.Checkpoint{Root: make([]byte, 32)}, CurrentJustifiedCheckpoint: &ethpb.Checkpoint{Root: make([]byte, 32)}}
 	beaconState, err := state_native.InitializeFromProtoPhase0(bs)
 	require.NoError(b, err)
-	wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
-	require.NoError(b, err)
-	require.NoError(b, s.insertBlockToForkchoiceStore(ctx, wsb.Block(), r, beaconState))
+	require.NoError(b, s.cfg.ForkChoiceStore.InsertNode(ctx, beaconState, r))

 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
--- a/beacon-chain/blockchain/setup_test.go
+++ b/beacon-chain/blockchain/setup_test.go
@@ -52,6 +52,11 @@ func (mb *mockBroadcaster) BroadcastSyncCommitteeMessage(_ context.Context, _ ui
 	return nil
 }

+func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.SignedBlobSidecar) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }

--- a/beacon-chain/blockchain/testing/mock.go
+++ b/beacon-chain/blockchain/testing/mock.go
@@ -69,6 +69,7 @@ type ChainService struct {
 	OptimisticCheckRootReceived [32]byte
 	FinalizedRoots              map[[32]byte]bool
 	OptimisticRoots             map[[32]byte]bool
+	BlockSlot                   primitives.Slot
 }

 func (s *ChainService) Ancestor(ctx context.Context, root []byte, slot primitives.Slot) ([]byte, error) {
@@ -320,7 +321,7 @@ func (_ *ChainService) ReceiveAttestation(_ context.Context, _ *ethpb.Attestatio
 }

 // AttestationTargetState mocks AttestationTargetState method in chain service.
-func (s *ChainService) AttestationTargetState(_ context.Context, _ *ethpb.Checkpoint) (state.BeaconState, error) {
+func (s *ChainService) AttestationTargetState(_ context.Context, _ *ethpb.Checkpoint) (state.ReadOnlyBeaconState, error) {
 	return s.State, nil
 }

@@ -389,6 +390,11 @@ func (s *ChainService) HasBlock(ctx context.Context, rt [32]byte) bool {
 	return s.InitSyncBlockRoots[rt]
 }

+// RecentBlockSlot mocks the same method in the chain service.
+func (s *ChainService) RecentBlockSlot([32]byte) (primitives.Slot, error) {
+	return s.BlockSlot, nil
+}
+
 // HeadGenesisValidatorsRoot mocks HeadGenesisValidatorsRoot method in chain service.
 func (_ *ChainService) HeadGenesisValidatorsRoot() [32]byte {
 	return [32]byte{}
--- a/beacon-chain/builder/BUILD.bazel
+++ b/beacon-chain/builder/BUILD.bazel
@@ -15,10 +15,12 @@ go_library(
        "//beacon-chain/cache:go_default_library",
        "//beacon-chain/db:go_default_library",
        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
        "//consensus-types/interfaces:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//monitoring/tracing:go_default_library",
+        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
        "@com_github_prometheus_client_golang//prometheus:go_default_library",
--- a/beacon-chain/builder/service.go
+++ b/beacon-chain/builder/service.go
@@ -2,6 +2,7 @@ package builder

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

@@ -10,10 +11,12 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v4/monitoring/tracing"
+	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	log "github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
@@ -24,7 +27,7 @@ var ErrNoBuilder = errors.New("builder endpoint not configured")

 // BlockBuilder defines the interface for interacting with the block builder
 type BlockBuilder interface {
-	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, error)
+	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error)
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error)
 	RegisterValidator(ctx context.Context, reg []*ethpb.SignedValidatorRegistrationV1) error
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
@@ -87,7 +90,7 @@ func (s *Service) Stop() error {
 }

 // SubmitBlindedBlock submits a blinded block to the builder relay network.
-func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, error) {
+func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock, blobs []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlock")
 	defer span.End()
 	start := time.Now()
@@ -95,10 +98,13 @@ func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlyS
 		submitBlindedBlockLatency.Observe(float64(time.Since(start).Milliseconds()))
 	}()
 	if s.c == nil {
-		return nil, ErrNoBuilder
+		return nil, nil, ErrNoBuilder
+	}
+	if uint64(len(blobs)) > fieldparams.MaxBlobsPerBlock {
+		return nil, nil, fmt.Errorf("blob count %d beyond max limit of %d", len(blobs), fieldparams.MaxBlobsPerBlock)
 	}

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

 // GetHeader retrieves the header for a given slot and parent hash from the builder relay network.
--- a/beacon-chain/builder/service_test.go
+++ b/beacon-chain/builder/service_test.go
@@ -3,6 +3,7 @@ package builder
 import (
 	"context"
 	"testing"
+	"time"

 	buildertesting "github.com/prysmaticlabs/prysm/v4/api/client/builder/testing"
 	blockchainTesting "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/testing"
@@ -38,6 +39,21 @@ func Test_RegisterValidator(t *testing.T) {
 	assert.Equal(t, true, builder.RegisteredVals[pubkey])
 }

+func Test_RegisterValidator_WithCache(t *testing.T) {
+	ctx := context.Background()
+	headFetcher := &blockchainTesting.ChainService{}
+	builder := buildertesting.NewClient()
+	s, err := NewService(ctx, WithRegistrationCache(), WithHeadFetcher(headFetcher), WithBuilderClient(&builder))
+	require.NoError(t, err)
+	pubkey := bytesutil.ToBytes48([]byte("pubkey"))
+	var feeRecipient [20]byte
+	reg := &eth.ValidatorRegistrationV1{Pubkey: pubkey[:], Timestamp: uint64(time.Now().UTC().Unix()), FeeRecipient: feeRecipient[:]}
+	require.NoError(t, s.RegisterValidator(ctx, []*eth.SignedValidatorRegistrationV1{{Message: reg}}))
+	registration, err := s.registrationCache.RegistrationByIndex(0)
+	require.NoError(t, err)
+	require.DeepEqual(t, reg, registration)
+}
+
 func Test_BuilderMethodsWithouClient(t *testing.T) {
 	s, err := NewService(context.Background())
 	require.NoError(t, err)
@@ -46,7 +62,7 @@ func Test_BuilderMethodsWithouClient(t *testing.T) {
 	_, err = s.GetHeader(context.Background(), 0, [32]byte{}, [48]byte{})
 	assert.ErrorContains(t, ErrNoBuilder.Error(), err)

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

 	err = s.RegisterValidator(context.Background(), nil)
--- a/beacon-chain/builder/testing/BUILD.bazel
+++ b/beacon-chain/builder/testing/BUILD.bazel
@@ -16,6 +16,7 @@ go_library(
        "//consensus-types/primitives:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
--- a/beacon-chain/builder/testing/mock.go
+++ b/beacon-chain/builder/testing/mock.go
@@ -13,6 +13,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	v1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

@@ -26,9 +27,12 @@ type MockBuilderService struct {
 	HasConfigured         bool
 	Payload               *v1.ExecutionPayload
 	PayloadCapella        *v1.ExecutionPayloadCapella
+	PayloadDeneb          *v1.ExecutionPayloadDeneb
+	BlobBundle            *v1.BlobsBundle
 	ErrSubmitBlindedBlock error
 	Bid                   *ethpb.SignedBuilderBid
 	BidCapella            *ethpb.SignedBuilderBidCapella
+	BidDeneb              *ethpb.SignedBuilderBidDeneb
 	RegistrationCache     *cache.RegistrationCache
 	ErrGetHeader          error
 	ErrRegisterValidator  error
@@ -41,23 +45,36 @@ func (s *MockBuilderService) Configured() bool {
 }

 // SubmitBlindedBlock for mocking.
-func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, error) {
-	if s.Payload != nil {
+func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock, _ []*ethpb.SignedBlindedBlobSidecar) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+	switch b.Version() {
+	case version.Bellatrix:
 		w, err := blocks.WrappedExecutionPayload(s.Payload)
 		if err != nil {
-			return nil, errors.Wrap(err, "could not wrap payload")
+			return nil, nil, errors.Wrap(err, "could not wrap payload")
 		}
-		return w, s.ErrSubmitBlindedBlock
+		return w, nil, s.ErrSubmitBlindedBlock
+	case version.Capella:
+		w, err := blocks.WrappedExecutionPayloadCapella(s.PayloadCapella, 0)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not wrap capella payload")
+		}
+		return w, nil, s.ErrSubmitBlindedBlock
+	case version.Deneb:
+		w, err := blocks.WrappedExecutionPayloadDeneb(s.PayloadDeneb, 0)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not wrap deneb payload")
+		}
+		return w, s.BlobBundle, s.ErrSubmitBlindedBlock
+	default:
+		return nil, nil, errors.New("unknown block version for mocking")
 	}
-	w, err := blocks.WrappedExecutionPayloadCapella(s.PayloadCapella, 0)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not wrap capella payload")
-	}
-	return w, s.ErrSubmitBlindedBlock
 }

 // GetHeader for mocking.
 func (s *MockBuilderService) GetHeader(_ context.Context, slot primitives.Slot, _ [32]byte, _ [48]byte) (builder.SignedBid, error) {
+	if slots.ToEpoch(slot) >= params.BeaconConfig().DenebForkEpoch || s.BidDeneb != nil {
+		return builder.WrappedSignedBuilderBidDeneb(s.BidDeneb)
+	}
 	if slots.ToEpoch(slot) >= params.BeaconConfig().CapellaForkEpoch || s.BidCapella != nil {
 		return builder.WrappedSignedBuilderBidCapella(s.BidCapella)
 	}
--- a/beacon-chain/cache/BUILD.bazel
+++ b/beacon-chain/cache/BUILD.bazel
@@ -34,6 +34,7 @@ go_library(
    deps = [
        "//beacon-chain/state:go_default_library",
        "//cache/lru:go_default_library",
+        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//container/slice:go_default_library",
@@ -87,7 +88,6 @@ go_test(
        "//testing/util:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_google_gofuzz//:go_default_library",
-        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
    ],
 )
--- a/beacon-chain/cache/depositcache/deposits_cache_test.go
+++ b/beacon-chain/cache/depositcache/deposits_cache_test.go
@@ -804,7 +804,7 @@ func TestFinalizedDeposits_ReturnsTrieCorrectly(t *testing.T) {
 	require.NoError(t, dc.InsertFinalizedDeposits(context.Background(), 3))
 	require.NoError(t, dc.InsertFinalizedDeposits(context.Background(), 4))

-	// Mimick finalized deposit trie fetch.
+	// Mimic finalized deposit trie fetch.
 	fd := dc.FinalizedDeposits(context.Background())
 	deps := dc.NonFinalizedDeposits(context.Background(), fd.MerkleTrieIndex, big.NewInt(14))
 	insertIndex := fd.MerkleTrieIndex + 1
--- a/beacon-chain/cache/payload_id.go
+++ b/beacon-chain/cache/payload_id.go
@@ -4,35 +4,41 @@ import (
 	"bytes"
 	"sync"

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

+const keyLength = 40
 const vIdLength = 8
 const pIdLength = 8
 const vpIdsLength = vIdLength + pIdLength

 // ProposerPayloadIDsCache is a cache of proposer payload IDs.
-// The key is the slot. The value is the concatenation of the proposer and payload IDs. 8 bytes each.
+// The key is the concatenation of the slot and the block root.
+// The value is the concatenation of the proposer and payload IDs, 8 bytes each.
 type ProposerPayloadIDsCache struct {
-	slotToProposerAndPayloadIDs map[[40]byte][vpIdsLength]byte
+	slotToProposerAndPayloadIDs map[[keyLength]byte][vpIdsLength]byte
 	sync.RWMutex
 }

 // NewProposerPayloadIDsCache creates a new proposer payload IDs cache.
 func NewProposerPayloadIDsCache() *ProposerPayloadIDsCache {
 	return &ProposerPayloadIDsCache{
-		slotToProposerAndPayloadIDs: make(map[[40]byte][vpIdsLength]byte),
+		slotToProposerAndPayloadIDs: make(map[[keyLength]byte][vpIdsLength]byte),
 	}
 }

-// GetProposerPayloadIDs returns the proposer and  payload IDs for the given slot.
-func (f *ProposerPayloadIDsCache) GetProposerPayloadIDs(slot primitives.Slot, r [32]byte) (primitives.ValidatorIndex, [8]byte, bool) {
+// GetProposerPayloadIDs returns the proposer and payload IDs for the given slot and head root to build the block.
+func (f *ProposerPayloadIDsCache) GetProposerPayloadIDs(
+	slot primitives.Slot,
+	r [fieldparams.RootLength]byte,
+) (primitives.ValidatorIndex, [pIdLength]byte, bool) {
 	f.RLock()
 	defer f.RUnlock()
 	ids, ok := f.slotToProposerAndPayloadIDs[idKey(slot, r)]
 	if !ok {
-		return 0, [8]byte{}, false
+		return 0, [pIdLength]byte{}, false
 	}
 	vId := ids[:vIdLength]

@@ -43,8 +49,13 @@ func (f *ProposerPayloadIDsCache) GetProposerPayloadIDs(slot primitives.Slot, r
 	return primitives.ValidatorIndex(bytesutil.BytesToUint64BigEndian(vId)), pId, true
 }

-// SetProposerAndPayloadIDs sets the proposer and payload IDs for the given slot.
-func (f *ProposerPayloadIDsCache) SetProposerAndPayloadIDs(slot primitives.Slot, vId primitives.ValidatorIndex, pId [8]byte, r [32]byte) {
+// SetProposerAndPayloadIDs sets the proposer and payload IDs for the given slot and head root to build block.
+func (f *ProposerPayloadIDsCache) SetProposerAndPayloadIDs(
+	slot primitives.Slot,
+	vId primitives.ValidatorIndex,
+	pId [pIdLength]byte,
+	r [fieldparams.RootLength]byte,
+) {
 	f.Lock()
 	defer f.Unlock()
 	var vIdBytes [vIdLength]byte
@@ -63,7 +74,7 @@ func (f *ProposerPayloadIDsCache) SetProposerAndPayloadIDs(slot primitives.Slot,
 	}
 }

-// PrunePayloadIDs removes the payload id entries that's current than input slot.
+// PrunePayloadIDs removes the payload ID entries older than input slot.
 func (f *ProposerPayloadIDsCache) PrunePayloadIDs(slot primitives.Slot) {
 	f.Lock()
 	defer f.Unlock()
@@ -76,8 +87,8 @@ func (f *ProposerPayloadIDsCache) PrunePayloadIDs(slot primitives.Slot) {
 	}
 }

-func idKey(slot primitives.Slot, r [32]byte) [40]byte {
-	var k [40]byte
+func idKey(slot primitives.Slot, r [fieldparams.RootLength]byte) [keyLength]byte {
+	var k [keyLength]byte
 	copy(k[:], append(bytesutil.Uint64ToBytesBigEndian(uint64(slot)), r[:]...))
 	return k
 }
--- a/beacon-chain/cache/registration.go
+++ b/beacon-chain/cache/registration.go
@@ -3,15 +3,11 @@ package cache
 import (
 	"context"
 	"sync"
-	"time"

 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v4/math"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
-	log "github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )

@@ -38,33 +34,10 @@ func (regCache *RegistrationCache) RegistrationByIndex(id primitives.ValidatorIn
 		regCache.lock.RUnlock()
 		return nil, errors.Wrapf(ErrNotFoundRegistration, "validator id %d", id)
 	}
-	isExpired, err := RegistrationTimeStampExpired(v.Timestamp)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to check registration expiration")
-	}
-	if isExpired {
-		regCache.lock.RUnlock()
-		regCache.lock.Lock()
-		defer regCache.lock.Unlock()
-		delete(regCache.indexToRegistration, id)
-		log.Warnf("registration for validator index %d expired at unix time %d", id, v.Timestamp)
-		return nil, errors.Wrapf(ErrNotFoundRegistration, "validator id %d", id)
-	}
 	regCache.lock.RUnlock()
 	return v, nil
 }

-func RegistrationTimeStampExpired(ts uint64) (bool, error) {
-	// safely convert unint64 to int64
-	i, err := math.Int(ts)
-	if err != nil {
-		return false, err
-	}
-	expiryDuration := params.BeaconConfig().RegistrationDuration
-	// registered time + expiration duration < current time = expired
-	return time.Unix(int64(i), 0).Add(expiryDuration).Before(time.Now()), nil
-}
-
 // UpdateIndexToRegisteredMap adds or updates values in the cache based on the argument.
 func (regCache *RegistrationCache) UpdateIndexToRegisteredMap(ctx context.Context, m map[primitives.ValidatorIndex]*ethpb.ValidatorRegistrationV1) {
 	_, span := trace.StartSpan(ctx, "RegistrationCache.UpdateIndexToRegisteredMap")
--- a/beacon-chain/cache/registration_test.go
+++ b/beacon-chain/cache/registration_test.go
@@ -6,15 +6,12 @@ import (
 	"time"

 	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
-	logTest "github.com/sirupsen/logrus/hooks/test"
 )

 func TestRegistrationCache(t *testing.T) {
-	hook := logTest.NewGlobal()
 	pubkey, err := hexutil.Decode("0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
 	require.NoError(t, err)
 	validatorIndex := primitives.ValidatorIndex(1)
@@ -31,29 +28,14 @@ func TestRegistrationCache(t *testing.T) {
 	reg, err := cache.RegistrationByIndex(validatorIndex)
 	require.NoError(t, err)
 	require.Equal(t, string(reg.Pubkey), string(pubkey))
-	t.Run("Registration expired", func(t *testing.T) {
-		validatorIndex2 := primitives.ValidatorIndex(2)
-		overExpirationPadTime := time.Second * time.Duration(params.BeaconConfig().SecondsPerSlot*uint64(params.BeaconConfig().SlotsPerEpoch)*4) // 4 epochs
-		m[validatorIndex2] = &ethpb.ValidatorRegistrationV1{
-			FeeRecipient: []byte{},
-			GasLimit:     100,
-			Timestamp:    uint64(time.Now().Add(-1 * overExpirationPadTime).Unix()),
-			Pubkey:       pubkey,
-		}
-		cache.UpdateIndexToRegisteredMap(context.Background(), m)
-		_, err := cache.RegistrationByIndex(validatorIndex2)
-		require.ErrorContains(t, "no validator registered", err)
-		require.LogsContain(t, hook, "expired")
-	})
-	t.Run("Registration close to expiration still passes", func(t *testing.T) {
+	t.Run("successfully updates", func(t *testing.T) {
 		pubkey, err := hexutil.Decode("0x88247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
 		require.NoError(t, err)
 		validatorIndex2 := primitives.ValidatorIndex(2)
-		overExpirationPadTime := time.Second * time.Duration((params.BeaconConfig().SecondsPerSlot*uint64(params.BeaconConfig().SlotsPerEpoch)*3)-5) // 3 epochs - 5 seconds
 		m[validatorIndex2] = &ethpb.ValidatorRegistrationV1{
 			FeeRecipient: []byte{},
 			GasLimit:     100,
-			Timestamp:    uint64(time.Now().Add(-1 * overExpirationPadTime).Unix()),
+			Timestamp:    uint64(time.Now().Unix()),
 			Pubkey:       pubkey,
 		}
 		cache.UpdateIndexToRegisteredMap(context.Background(), m)
@@ -62,21 +44,3 @@ func TestRegistrationCache(t *testing.T) {
 		require.Equal(t, string(reg.Pubkey), string(pubkey))
 	})
 }
-
-func Test_RegistrationTimeStampExpired(t *testing.T) {
-	// expiration set at 3 epochs
-	t.Run("expired registration", func(t *testing.T) {
-		overExpirationPadTime := time.Second * time.Duration(params.BeaconConfig().SecondsPerSlot*uint64(params.BeaconConfig().SlotsPerEpoch)*4) // 4 epochs
-		ts := uint64(time.Now().Add(-1 * overExpirationPadTime).Unix())
-		isExpired, err := RegistrationTimeStampExpired(ts)
-		require.NoError(t, err)
-		require.Equal(t, true, isExpired)
-	})
-	t.Run("is not expired registration", func(t *testing.T) {
-		overExpirationPadTime := time.Second * time.Duration((params.BeaconConfig().SecondsPerSlot*uint64(params.BeaconConfig().SlotsPerEpoch)*3)-5) // 3 epochs -5 seconds
-		ts := uint64(time.Now().Add(-1 * overExpirationPadTime).Unix())
-		isExpired, err := RegistrationTimeStampExpired(ts)
-		require.NoError(t, err)
-		require.Equal(t, false, isExpired)
-	})
-}
--- a/beacon-chain/core/altair/epoch_precompute.go
+++ b/beacon-chain/core/altair/epoch_precompute.go
@@ -13,6 +13,15 @@ import (
 	"go.opencensus.io/trace"
 )

+// AttDelta contains rewards and penalties for a single attestation.
+type AttDelta struct {
+	HeadReward    uint64
+	SourceReward  uint64
+	SourcePenalty uint64
+	TargetReward  uint64
+	TargetPenalty uint64
+}
+
 // InitializePrecomputeValidators precomputes individual validator for its attested balances and the total sum of validators attested balances of the epoch.
 func InitializePrecomputeValidators(ctx context.Context, beaconState state.BeaconState) ([]*precompute.Validator, *precompute.Balance, error) {
 	ctx, span := trace.StartSpan(ctx, "altair.InitializePrecomputeValidators")
@@ -226,7 +235,7 @@ func ProcessRewardsAndPenaltiesPrecompute(
 		return beaconState, errors.New("validator registries not the same length as state's validator registries")
 	}

-	attsRewards, attsPenalties, err := AttestationsDelta(beaconState, bal, vals)
+	attDeltas, err := AttestationsDelta(beaconState, bal, vals)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get attestation delta")
 	}
@@ -237,11 +246,12 @@ func ProcessRewardsAndPenaltiesPrecompute(

 		// Compute the post balance of the validator after accounting for the
 		// attester and proposer rewards and penalties.
-		balances[i], err = helpers.IncreaseBalanceWithVal(balances[i], attsRewards[i])
+		delta := attDeltas[i]
+		balances[i], err = helpers.IncreaseBalanceWithVal(balances[i], delta.HeadReward+delta.SourceReward+delta.TargetReward)
 		if err != nil {
 			return nil, err
 		}
-		balances[i] = helpers.DecreaseBalanceWithVal(balances[i], attsPenalties[i])
+		balances[i] = helpers.DecreaseBalanceWithVal(balances[i], delta.SourcePenalty+delta.TargetPenalty)

 		vals[i].AfterEpochTransitionBalance = balances[i]
 	}
@@ -255,10 +265,8 @@ func ProcessRewardsAndPenaltiesPrecompute(

 // AttestationsDelta computes and returns the rewards and penalties differences for individual validators based on the
 // voting records.
-func AttestationsDelta(beaconState state.BeaconState, bal *precompute.Balance, vals []*precompute.Validator) (rewards, penalties []uint64, err error) {
-	numOfVals := beaconState.NumValidators()
-	rewards = make([]uint64, numOfVals)
-	penalties = make([]uint64, numOfVals)
+func AttestationsDelta(beaconState state.BeaconState, bal *precompute.Balance, vals []*precompute.Validator) ([]*AttDelta, error) {
+	attDeltas := make([]*AttDelta, len(vals))

 	cfg := params.BeaconConfig()
 	prevEpoch := time.PrevEpoch(beaconState)
@@ -272,29 +280,29 @@ func AttestationsDelta(beaconState state.BeaconState, bal *precompute.Balance, v
 	bias := cfg.InactivityScoreBias
 	inactivityPenaltyQuotient, err := beaconState.InactivityPenaltyQuotient()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	inactivityDenominator := bias * inactivityPenaltyQuotient

 	for i, v := range vals {
-		rewards[i], penalties[i], err = attestationDelta(bal, v, baseRewardMultiplier, inactivityDenominator, leak)
+		attDeltas[i], err = attestationDelta(bal, v, baseRewardMultiplier, inactivityDenominator, leak)
 		if err != nil {
-			return nil, nil, err
+			return nil, err
 		}
 	}

-	return rewards, penalties, nil
+	return attDeltas, nil
 }

 func attestationDelta(
 	bal *precompute.Balance,
 	val *precompute.Validator,
 	baseRewardMultiplier, inactivityDenominator uint64,
-	inactivityLeak bool) (reward, penalty uint64, err error) {
+	inactivityLeak bool) (*AttDelta, error) {
 	eligible := val.IsActivePrevEpoch || (val.IsSlashed && !val.IsWithdrawableCurrentEpoch)
 	// Per spec `ActiveCurrentEpoch` can't be 0 to process attestation delta.
 	if !eligible || bal.ActiveCurrentEpoch == 0 {
-		return 0, 0, nil
+		return &AttDelta{}, nil
 	}

 	cfg := params.BeaconConfig()
@@ -307,32 +315,32 @@ func attestationDelta(
 	srcWeight := cfg.TimelySourceWeight
 	tgtWeight := cfg.TimelyTargetWeight
 	headWeight := cfg.TimelyHeadWeight
-	reward, penalty = uint64(0), uint64(0)
+	attDelta := &AttDelta{}
 	// Process source reward / penalty
 	if val.IsPrevEpochSourceAttester && !val.IsSlashed {
 		if !inactivityLeak {
 			n := baseReward * srcWeight * (bal.PrevEpochAttested / increment)
-			reward += n / (activeIncrement * weightDenominator)
+			attDelta.SourceReward += n / (activeIncrement * weightDenominator)
 		}
 	} else {
-		penalty += baseReward * srcWeight / weightDenominator
+		attDelta.SourcePenalty += baseReward * srcWeight / weightDenominator
 	}

 	// Process target reward / penalty
 	if val.IsPrevEpochTargetAttester && !val.IsSlashed {
 		if !inactivityLeak {
 			n := baseReward * tgtWeight * (bal.PrevEpochTargetAttested / increment)
-			reward += n / (activeIncrement * weightDenominator)
+			attDelta.TargetReward += n / (activeIncrement * weightDenominator)
 		}
 	} else {
-		penalty += baseReward * tgtWeight / weightDenominator
+		attDelta.TargetPenalty += baseReward * tgtWeight / weightDenominator
 	}

 	// Process head reward / penalty
 	if val.IsPrevEpochHeadAttester && !val.IsSlashed {
 		if !inactivityLeak {
 			n := baseReward * headWeight * (bal.PrevEpochHeadAttested / increment)
-			reward += n / (activeIncrement * weightDenominator)
+			attDelta.HeadReward += n / (activeIncrement * weightDenominator)
 		}
 	}

@@ -341,10 +349,10 @@ func attestationDelta(
 	if !val.IsPrevEpochTargetAttester || val.IsSlashed {
 		n, err := math.Mul64(effectiveBalance, val.InactivityScore)
 		if err != nil {
-			return 0, 0, err
+			return &AttDelta{}, err
 		}
-		penalty += n / inactivityDenominator
+		attDelta.TargetPenalty += n / inactivityDenominator
 	}

-	return reward, penalty, nil
+	return attDelta, nil
 }
--- a/beacon-chain/core/altair/epoch_precompute_test.go
+++ b/beacon-chain/core/altair/epoch_precompute_test.go
@@ -213,9 +213,16 @@ func TestAttestationsDelta(t *testing.T) {
 	require.NoError(t, err)
 	validators, balance, err = ProcessEpochParticipation(context.Background(), s, balance, validators)
 	require.NoError(t, err)
-	rewards, penalties, err := AttestationsDelta(s, balance, validators)
+	deltas, err := AttestationsDelta(s, balance, validators)
 	require.NoError(t, err)

+	rewards := make([]uint64, len(deltas))
+	penalties := make([]uint64, len(deltas))
+	for i, d := range deltas {
+		rewards[i] = d.HeadReward + d.SourceReward + d.TargetReward
+		penalties[i] = d.SourcePenalty + d.TargetPenalty
+	}
+
 	// Reward amount should increase as validator index increases due to setup.
 	for i := 1; i < len(rewards); i++ {
 		require.Equal(t, true, rewards[i] > rewards[i-1])
@@ -244,9 +251,16 @@ func TestAttestationsDeltaBellatrix(t *testing.T) {
 	require.NoError(t, err)
 	validators, balance, err = ProcessEpochParticipation(context.Background(), s, balance, validators)
 	require.NoError(t, err)
-	rewards, penalties, err := AttestationsDelta(s, balance, validators)
+	deltas, err := AttestationsDelta(s, balance, validators)
 	require.NoError(t, err)

+	rewards := make([]uint64, len(deltas))
+	penalties := make([]uint64, len(deltas))
+	for i, d := range deltas {
+		rewards[i] = d.HeadReward + d.SourceReward + d.TargetReward
+		penalties[i] = d.SourcePenalty + d.TargetPenalty
+	}
+
 	// Reward amount should increase as validator index increases due to setup.
 	for i := 1; i < len(rewards); i++ {
 		require.Equal(t, true, rewards[i] > rewards[i-1])
@@ -285,8 +299,15 @@ func TestProcessRewardsAndPenaltiesPrecompute_Ok(t *testing.T) {
 	}

 	wanted := make([]uint64, s.NumValidators())
-	rewards, penalties, err := AttestationsDelta(s, balance, validators)
+	deltas, err := AttestationsDelta(s, balance, validators)
 	require.NoError(t, err)
+
+	rewards := make([]uint64, len(deltas))
+	penalties := make([]uint64, len(deltas))
+	for i, d := range deltas {
+		rewards[i] = d.HeadReward + d.SourceReward + d.TargetReward
+		penalties[i] = d.SourcePenalty + d.TargetPenalty
+	}
 	for i := range rewards {
 		wanted[i] += rewards[i]
 	}
--- a/beacon-chain/core/altair/sync_committee.go
+++ b/beacon-chain/core/altair/sync_committee.go
@@ -2,6 +2,7 @@ package altair

 import (
 	"context"
+	goErrors "errors"
 	"fmt"
 	"time"

@@ -22,6 +23,10 @@ import (

 const maxRandomByte = uint64(1<<8 - 1)

+var (
+	ErrTooLate = errors.New("sync message is too late")
+)
+
 // ValidateNilSyncContribution validates the following fields are not nil:
 // -the contribution and proof itself
 // -the message within contribution and proof
@@ -217,7 +222,7 @@ func ValidateSyncMessageTime(slot primitives.Slot, genesisTime time.Time, clockD
 	upperBound := time.Now().Add(clockDisparity)
 	// Verify sync message slot is within the time range.
 	if messageTime.Before(lowerBound) || messageTime.After(upperBound) {
-		return fmt.Errorf(
+		syncErr := fmt.Errorf(
 			"sync message time %v (slot %d) not within allowable range of %v (slot %d) to %v (slot %d)",
 			messageTime,
 			slot,
@@ -226,6 +231,11 @@ func ValidateSyncMessageTime(slot primitives.Slot, genesisTime time.Time, clockD
 			upperBound,
 			uint64(upperBound.Unix()-genesisTime.Unix())/params.BeaconConfig().SecondsPerSlot,
 		)
+		// Wrap error message if sync message is too late.
+		if messageTime.Before(lowerBound) {
+			syncErr = goErrors.Join(ErrTooLate, syncErr)
+		}
+		return syncErr
 	}
 	return nil
 }
--- a/beacon-chain/core/blocks/genesis.go
+++ b/beacon-chain/core/blocks/genesis.go
@@ -145,6 +145,40 @@ func NewGenesisBlockForState(ctx context.Context, st state.BeaconState) (interfa
 			},
 			Signature: params.BeaconConfig().EmptySignature[:],
 		})
+	case *ethpb.BeaconStateDeneb:
+		return blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockDeneb{
+			Block: &ethpb.BeaconBlockDeneb{
+				ParentRoot: params.BeaconConfig().ZeroHash[:],
+				StateRoot:  root[:],
+				Body: &ethpb.BeaconBlockBodyDeneb{
+					RandaoReveal: make([]byte, 96),
+					Eth1Data: &ethpb.Eth1Data{
+						DepositRoot: make([]byte, 32),
+						BlockHash:   make([]byte, 32),
+					},
+					Graffiti: make([]byte, 32),
+					SyncAggregate: &ethpb.SyncAggregate{
+						SyncCommitteeBits:      make([]byte, fieldparams.SyncCommitteeLength/8),
+						SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+					},
+					ExecutionPayload: &enginev1.ExecutionPayloadDeneb{ // Deneb difference.
+						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: make([]byte, 32),
+						BlockHash:     make([]byte, 32),
+						Transactions:  make([][]byte, 0),
+						Withdrawals:   make([]*enginev1.Withdrawal, 0),
+					},
+					BlsToExecutionChanges: make([]*ethpb.SignedBLSToExecutionChange, 0),
+					BlobKzgCommitments:    make([][]byte, 0),
+				},
+			},
+			Signature: params.BeaconConfig().EmptySignature[:],
+		})
 	default:
 		return nil, ErrUnrecognizedState
 	}
--- a/beacon-chain/core/blocks/payload.go
+++ b/beacon-chain/core/blocks/payload.go
@@ -61,7 +61,7 @@ func IsExecutionBlock(body interfaces.ReadOnlyBeaconBlockBody) (bool, error) {
 	}
 	payload, err := body.Execution()
 	switch {
-	case errors.Is(err, consensus_types.ErrUnsupportedGetter):
+	case errors.Is(err, consensus_types.ErrUnsupportedField):
 		return false, nil
 	case err != nil:
 		return false, err
--- a/beacon-chain/core/deneb/BUILD.bazel
+++ b/beacon-chain/core/deneb/BUILD.bazel
@@ -0,0 +1,30 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["upgrade.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/deneb",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/core/time:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//beacon-chain/state/state-native:go_default_library",
+        "//config/params:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["upgrade_test.go"],
+    deps = [
+        ":go_default_library",
+        "//beacon-chain/core/time:go_default_library",
+        "//config/params:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+    ],
+)
--- a/beacon-chain/core/deneb/upgrade.go
+++ b/beacon-chain/core/deneb/upgrade.go
@@ -0,0 +1,115 @@
+package deneb
+
+import (
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	state_native "github.com/prysmaticlabs/prysm/v4/beacon-chain/state/state-native"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+)
+
+// UpgradeToDeneb updates inputs a generic state to return the version Deneb state.
+func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
+	epoch := time.CurrentEpoch(state)
+
+	currentSyncCommittee, err := state.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSyncCommittee, err := state.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	prevEpochParticipation, err := state.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currentEpochParticipation, err := state.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	inactivityScores, err := state.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	payloadHeader, err := state.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	txRoot, err := payloadHeader.TransactionsRoot()
+	if err != nil {
+		return nil, err
+	}
+	wdRoot, err := payloadHeader.WithdrawalsRoot()
+	if err != nil {
+		return nil, err
+	}
+	wi, err := state.NextWithdrawalIndex()
+	if err != nil {
+		return nil, err
+	}
+	vi, err := state.NextWithdrawalValidatorIndex()
+	if err != nil {
+		return nil, err
+	}
+	summaries, err := state.HistoricalSummaries()
+	if err != nil {
+		return nil, err
+	}
+
+	s := &ethpb.BeaconStateDeneb{
+		GenesisTime:           state.GenesisTime(),
+		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
+		Slot:                  state.Slot(),
+		Fork: &ethpb.Fork{
+			PreviousVersion: state.Fork().CurrentVersion,
+			CurrentVersion:  params.BeaconConfig().DenebForkVersion,
+			Epoch:           epoch,
+		},
+		LatestBlockHeader:           state.LatestBlockHeader(),
+		BlockRoots:                  state.BlockRoots(),
+		StateRoots:                  state.StateRoots(),
+		HistoricalRoots:             [][]byte{},
+		Eth1Data:                    state.Eth1Data(),
+		Eth1DataVotes:               state.Eth1DataVotes(),
+		Eth1DepositIndex:            state.Eth1DepositIndex(),
+		Validators:                  state.Validators(),
+		Balances:                    state.Balances(),
+		RandaoMixes:                 state.RandaoMixes(),
+		Slashings:                   state.Slashings(),
+		PreviousEpochParticipation:  prevEpochParticipation,
+		CurrentEpochParticipation:   currentEpochParticipation,
+		JustificationBits:           state.JustificationBits(),
+		PreviousJustifiedCheckpoint: state.PreviousJustifiedCheckpoint(),
+		CurrentJustifiedCheckpoint:  state.CurrentJustifiedCheckpoint(),
+		FinalizedCheckpoint:         state.FinalizedCheckpoint(),
+		InactivityScores:            inactivityScores,
+		CurrentSyncCommittee:        currentSyncCommittee,
+		NextSyncCommittee:           nextSyncCommittee,
+		LatestExecutionPayloadHeader: &enginev1.ExecutionPayloadHeaderDeneb{
+			ParentHash:       payloadHeader.ParentHash(),
+			FeeRecipient:     payloadHeader.FeeRecipient(),
+			StateRoot:        payloadHeader.StateRoot(),
+			ReceiptsRoot:     payloadHeader.ReceiptsRoot(),
+			LogsBloom:        payloadHeader.LogsBloom(),
+			PrevRandao:       payloadHeader.PrevRandao(),
+			BlockNumber:      payloadHeader.BlockNumber(),
+			GasLimit:         payloadHeader.GasLimit(),
+			GasUsed:          payloadHeader.GasUsed(),
+			Timestamp:        payloadHeader.Timestamp(),
+			ExtraData:        payloadHeader.ExtraData(),
+			BaseFeePerGas:    payloadHeader.BaseFeePerGas(),
+			BlockHash:        payloadHeader.BlockHash(),
+			ExcessDataGas:    0,
+			DataGasUsed:      0,
+			TransactionsRoot: txRoot,
+			WithdrawalsRoot:  wdRoot,
+		},
+		NextWithdrawalIndex:          wi,
+		NextWithdrawalValidatorIndex: vi,
+		HistoricalSummaries:          summaries,
+	}
+
+	return state_native.InitializeFromProtoUnsafeDeneb(s)
+}
--- a/beacon-chain/core/deneb/upgrade_test.go
+++ b/beacon-chain/core/deneb/upgrade_test.go
@@ -0,0 +1,94 @@
+package deneb_test
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/deneb"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
+)
+
+func TestUpgradeToDeneb(t *testing.T) {
+	st, _ := util.DeterministicGenesisStateCapella(t, params.BeaconConfig().MaxValidatorsPerCommittee)
+	preForkState := st.Copy()
+	mSt, err := deneb.UpgradeToDeneb(st)
+	require.NoError(t, err)
+
+	require.Equal(t, preForkState.GenesisTime(), mSt.GenesisTime())
+	require.DeepSSZEqual(t, preForkState.GenesisValidatorsRoot(), mSt.GenesisValidatorsRoot())
+	require.Equal(t, preForkState.Slot(), mSt.Slot())
+	require.DeepSSZEqual(t, preForkState.LatestBlockHeader(), mSt.LatestBlockHeader())
+	require.DeepSSZEqual(t, preForkState.BlockRoots(), mSt.BlockRoots())
+	require.DeepSSZEqual(t, preForkState.StateRoots(), mSt.StateRoots())
+	require.DeepSSZEqual(t, preForkState.Eth1Data(), mSt.Eth1Data())
+	require.DeepSSZEqual(t, preForkState.Eth1DataVotes(), mSt.Eth1DataVotes())
+	require.DeepSSZEqual(t, preForkState.Eth1DepositIndex(), mSt.Eth1DepositIndex())
+	require.DeepSSZEqual(t, preForkState.Validators(), mSt.Validators())
+	require.DeepSSZEqual(t, preForkState.Balances(), mSt.Balances())
+	require.DeepSSZEqual(t, preForkState.RandaoMixes(), mSt.RandaoMixes())
+	require.DeepSSZEqual(t, preForkState.Slashings(), mSt.Slashings())
+	require.DeepSSZEqual(t, preForkState.JustificationBits(), mSt.JustificationBits())
+	require.DeepSSZEqual(t, preForkState.PreviousJustifiedCheckpoint(), mSt.PreviousJustifiedCheckpoint())
+	require.DeepSSZEqual(t, preForkState.CurrentJustifiedCheckpoint(), mSt.CurrentJustifiedCheckpoint())
+	require.DeepSSZEqual(t, preForkState.FinalizedCheckpoint(), mSt.FinalizedCheckpoint())
+	numValidators := mSt.NumValidators()
+	p, err := mSt.PreviousEpochParticipation()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, make([]byte, numValidators), p)
+	p, err = mSt.CurrentEpochParticipation()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, make([]byte, numValidators), p)
+	s, err := mSt.InactivityScores()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
+
+	f := mSt.Fork()
+	require.DeepSSZEqual(t, &ethpb.Fork{
+		PreviousVersion: st.Fork().CurrentVersion,
+		CurrentVersion:  params.BeaconConfig().DenebForkVersion,
+		Epoch:           time.CurrentEpoch(st),
+	}, f)
+	csc, err := mSt.CurrentSyncCommittee()
+	require.NoError(t, err)
+	psc, err := preForkState.CurrentSyncCommittee()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, psc, csc)
+	nsc, err := mSt.NextSyncCommittee()
+	require.NoError(t, err)
+	psc, err = preForkState.NextSyncCommittee()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, psc, nsc)
+
+	header, err := mSt.LatestExecutionPayloadHeader()
+	require.NoError(t, err)
+	protoHeader, ok := header.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+	require.Equal(t, true, ok)
+	prevHeader, err := preForkState.LatestExecutionPayloadHeader()
+	require.NoError(t, err)
+	txRoot, err := prevHeader.TransactionsRoot()
+	require.NoError(t, err)
+
+	wdRoot, err := prevHeader.WithdrawalsRoot()
+	require.NoError(t, err)
+	wanted := &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       prevHeader.ParentHash(),
+		FeeRecipient:     prevHeader.FeeRecipient(),
+		StateRoot:        prevHeader.StateRoot(),
+		ReceiptsRoot:     prevHeader.ReceiptsRoot(),
+		LogsBloom:        prevHeader.LogsBloom(),
+		PrevRandao:       prevHeader.PrevRandao(),
+		BlockNumber:      prevHeader.BlockNumber(),
+		GasLimit:         prevHeader.GasLimit(),
+		GasUsed:          prevHeader.GasUsed(),
+		Timestamp:        prevHeader.Timestamp(),
+		BaseFeePerGas:    prevHeader.BaseFeePerGas(),
+		BlockHash:        prevHeader.BlockHash(),
+		TransactionsRoot: txRoot,
+		WithdrawalsRoot:  wdRoot,
+	}
+	require.DeepEqual(t, wanted, protoHeader)
+}
--- a/beacon-chain/core/helpers/BUILD.bazel
+++ b/beacon-chain/core/helpers/BUILD.bazel
@@ -38,6 +38,7 @@ go_library(
        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
+        "@io_opencensus_go//trace:go_default_library",
    ],
 )

@@ -68,7 +69,6 @@ go_test(
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//container/slice:go_default_library",
-        "//crypto/bls:go_default_library",
        "//crypto/hash:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
--- a/beacon-chain/core/helpers/attestation.go
+++ b/beacon-chain/core/helpers/attestation.go
@@ -8,13 +8,16 @@ import (

 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v4/crypto/bls"
 	"github.com/prysmaticlabs/prysm/v4/crypto/hash"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )

+var (
+	ErrTooLate = errors.New("attestation is too late")
+)
+
 // ValidateNilAttestation checks if any composite field of input attestation is nil.
 // Access to these nil fields will result in run time panic,
 // it is recommended to run these checks as first line of defense.
@@ -66,25 +69,6 @@ func IsAggregator(committeeCount uint64, slotSig []byte) (bool, error) {
 	return binary.LittleEndian.Uint64(b[:8])%modulo == 0, nil
 }

-// AggregateSignature returns the aggregated signature of the input attestations.
-//
-// Spec pseudocode definition:
-//
-//	def get_aggregate_signature(attestations: Sequence[Attestation]) -> BLSSignature:
-//	 signatures = [attestation.signature for attestation in attestations]
-//	 return bls.Aggregate(signatures)
-func AggregateSignature(attestations []*ethpb.Attestation) (bls.Signature, error) {
-	sigs := make([]bls.Signature, len(attestations))
-	var err error
-	for i := 0; i < len(sigs); i++ {
-		sigs[i], err = bls.SignatureFromBytes(attestations[i].Signature)
-		if err != nil {
-			return nil, err
-		}
-	}
-	return bls.AggregateSignatures(sigs), nil
-}
-
 // IsAggregated returns true if the attestation is an aggregated attestation,
 // false otherwise.
 func IsAggregated(attestation *ethpb.Attestation) bool {
@@ -183,11 +167,11 @@ func ValidateAttestationTime(attSlot primitives.Slot, genesisTime time.Time, clo
 		currentSlot,
 	)
 	if attTime.Before(lowerBounds) {
-		attReceivedTooEarlyCount.Inc()
-		return attError
+		attReceivedTooLateCount.Inc()
+		return errors.Join(ErrTooLate, attError)
 	}
 	if attTime.After(upperBounds) {
-		attReceivedTooLateCount.Inc()
+		attReceivedTooEarlyCount.Inc()
 		return attError
 	}
 	return nil
--- a/beacon-chain/core/helpers/attestation_test.go
+++ b/beacon-chain/core/helpers/attestation_test.go
@@ -10,8 +10,6 @@ import (
 	state_native "github.com/prysmaticlabs/prysm/v4/beacon-chain/state/state-native"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v4/crypto/bls"
-	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
@@ -45,44 +43,6 @@ func TestAttestation_IsAggregator(t *testing.T) {
 	})
 }

-func TestAttestation_AggregateSignature(t *testing.T) {
-	t.Run("verified", func(t *testing.T) {
-		pubkeys := make([]bls.PublicKey, 0, 100)
-		atts := make([]*ethpb.Attestation, 0, 100)
-		msg := bytesutil.ToBytes32([]byte("hello"))
-		for i := 0; i < 100; i++ {
-			priv, err := bls.RandKey()
-			require.NoError(t, err)
-			pub := priv.PublicKey()
-			sig := priv.Sign(msg[:])
-			pubkeys = append(pubkeys, pub)
-			att := &ethpb.Attestation{Signature: sig.Marshal()}
-			atts = append(atts, att)
-		}
-		aggSig, err := helpers.AggregateSignature(atts)
-		require.NoError(t, err)
-		assert.Equal(t, true, aggSig.FastAggregateVerify(pubkeys, msg), "Signature did not verify")
-	})
-
-	t.Run("not verified", func(t *testing.T) {
-		pubkeys := make([]bls.PublicKey, 0, 100)
-		atts := make([]*ethpb.Attestation, 0, 100)
-		msg := []byte("hello")
-		for i := 0; i < 100; i++ {
-			priv, err := bls.RandKey()
-			require.NoError(t, err)
-			pub := priv.PublicKey()
-			sig := priv.Sign(msg)
-			pubkeys = append(pubkeys, pub)
-			att := &ethpb.Attestation{Signature: sig.Marshal()}
-			atts = append(atts, att)
-		}
-		aggSig, err := helpers.AggregateSignature(atts[0 : len(atts)-2])
-		require.NoError(t, err)
-		assert.Equal(t, false, aggSig.FastAggregateVerify(pubkeys, bytesutil.ToBytes32(msg)), "Signature not suppose to verify")
-	})
-}
-
 func TestAttestation_ComputeSubnetForAttestation(t *testing.T) {
 	// Create 10 committees
 	committeeCount := uint64(10)
--- a/beacon-chain/core/helpers/validators.go
+++ b/beacon-chain/core/helpers/validators.go
@@ -17,6 +17,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	log "github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
 )

 var CommitteeCacheInProgressHit = promauto.NewCounter(prometheus.CounterOpts{
@@ -396,3 +397,22 @@ func isEligibleForActivation(activationEligibilityEpoch, activationEpoch, finali
 	return activationEligibilityEpoch <= finalizedEpoch &&
 		activationEpoch == params.BeaconConfig().FarFutureEpoch
 }
+
+// LastActivatedValidatorIndex provides the last activated validator given a state
+func LastActivatedValidatorIndex(ctx context.Context, st state.ReadOnlyBeaconState) (primitives.ValidatorIndex, error) {
+	_, span := trace.StartSpan(ctx, "helpers.LastActivatedValidatorIndex")
+	defer span.End()
+	var lastActivatedvalidatorIndex primitives.ValidatorIndex
+	// linear search because status are not sorted
+	for j := st.NumValidators() - 1; j >= 0; j-- {
+		val, err := st.ValidatorAtIndexReadOnly(primitives.ValidatorIndex(j))
+		if err != nil {
+			return 0, err
+		}
+		if IsActiveValidatorUsingTrie(val, time.CurrentEpoch(st)) {
+			lastActivatedvalidatorIndex = primitives.ValidatorIndex(j)
+			break
+		}
+	}
+	return lastActivatedvalidatorIndex, nil
+}
--- a/beacon-chain/core/helpers/validators_test.go
+++ b/beacon-chain/core/helpers/validators_test.go
@@ -727,3 +727,26 @@ func computeProposerIndexWithValidators(validators []*ethpb.Validator, activeInd
 		}
 	}
 }
+
+func TestLastActivatedValidatorIndex_OK(t *testing.T) {
+	beaconState, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{})
+	require.NoError(t, err)
+
+	validators := make([]*ethpb.Validator, 4)
+	balances := make([]uint64, len(validators))
+	for i := uint64(0); i < 4; i++ {
+		validators[i] = &ethpb.Validator{
+			PublicKey:             make([]byte, params.BeaconConfig().BLSPubkeyLength),
+			WithdrawalCredentials: make([]byte, 32),
+			EffectiveBalance:      32 * 1e9,
+			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
+		}
+		balances[i] = validators[i].EffectiveBalance
+	}
+	require.NoError(t, beaconState.SetValidators(validators))
+	require.NoError(t, beaconState.SetBalances(balances))
+
+	index, err := LastActivatedValidatorIndex(context.Background(), beaconState)
+	require.NoError(t, err)
+	require.Equal(t, index, primitives.ValidatorIndex(3))
+}
--- a/beacon-chain/core/time/slot_epoch.go
+++ b/beacon-chain/core/time/slot_epoch.go
@@ -81,6 +81,15 @@ func CanUpgradeToCapella(slot primitives.Slot) bool {
 	return epochStart && capellaEpoch
 }

+// CanUpgradeToDeneb returns true if the input `slot` can upgrade to Deneb.
+// Spec code:
+// If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == DENEB_FORK_EPOCH
+func CanUpgradeToDeneb(slot primitives.Slot) bool {
+	epochStart := slots.IsEpochStart(slot)
+	DenebEpoch := slots.ToEpoch(slot) == params.BeaconConfig().DenebForkEpoch
+	return epochStart && DenebEpoch
+}
+
 // CanProcessEpoch checks the eligibility to process epoch.
 // The epoch can be processed at the end of the last slot of every epoch.
 //
--- a/beacon-chain/core/time/slot_epoch_test.go
+++ b/beacon-chain/core/time/slot_epoch_test.go
@@ -298,3 +298,38 @@ func TestCanUpgradeToCapella(t *testing.T) {
 		})
 	}
 }
+
+func TestCanUpgradeToDeneb(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	bc := params.BeaconConfig()
+	bc.DenebForkEpoch = 5
+	params.OverrideBeaconConfig(bc)
+	tests := []struct {
+		name string
+		slot primitives.Slot
+		want bool
+	}{
+		{
+			name: "not epoch start",
+			slot: 1,
+			want: false,
+		},
+		{
+			name: "not deneb epoch",
+			slot: params.BeaconConfig().SlotsPerEpoch,
+			want: false,
+		},
+		{
+			name: "deneb epoch",
+			slot: primitives.Slot(params.BeaconConfig().DenebForkEpoch) * params.BeaconConfig().SlotsPerEpoch,
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := time.CanUpgradeToDeneb(tt.slot); got != tt.want {
+				t.Errorf("CanUpgradeToDeneb() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
--- a/beacon-chain/core/transition/BUILD.bazel
+++ b/beacon-chain/core/transition/BUILD.bazel
@@ -18,6 +18,7 @@ go_library(
        "//beacon-chain/core/altair:go_default_library",
        "//beacon-chain/core/blocks:go_default_library",
        "//beacon-chain/core/capella:go_default_library",
+        "//beacon-chain/core/deneb:go_default_library",
        "//beacon-chain/core/epoch:go_default_library",
        "//beacon-chain/core/epoch/precompute:go_default_library",
        "//beacon-chain/core/execution:go_default_library",
--- a/beacon-chain/core/transition/transition.go
+++ b/beacon-chain/core/transition/transition.go
@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/capella"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/deneb"
 	e "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/epoch"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/epoch/precompute"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/execution"
@@ -269,28 +270,10 @@ func ProcessSlots(ctx context.Context, state state.BeaconState, slot primitives.
 			return nil, errors.Wrap(err, "failed to increment state slot")
 		}

-		if time.CanUpgradeToAltair(state.Slot()) {
-			state, err = altair.UpgradeToAltair(ctx, state)
-			if err != nil {
-				tracing.AnnotateError(span, err)
-				return nil, err
-			}
-		}
-
-		if time.CanUpgradeToBellatrix(state.Slot()) {
-			state, err = execution.UpgradeToBellatrix(state)
-			if err != nil {
-				tracing.AnnotateError(span, err)
-				return nil, err
-			}
-		}
-
-		if time.CanUpgradeToCapella(state.Slot()) {
-			state, err = capella.UpgradeToCapella(state)
-			if err != nil {
-				tracing.AnnotateError(span, err)
-				return nil, err
-			}
+		state, err = UpgradeState(ctx, state)
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return nil, errors.Wrap(err, "failed to upgrade state")
 		}
 	}

@@ -301,6 +284,45 @@ func ProcessSlots(ctx context.Context, state state.BeaconState, slot primitives.
 	return state, nil
 }

+// UpgradeState upgrades the state to the next version if possible.
+func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconState, error) {
+	ctx, span := trace.StartSpan(ctx, "core.state.UpgradeState")
+	defer span.End()
+	var err error
+	if time.CanUpgradeToAltair(state.Slot()) {
+		state, err = altair.UpgradeToAltair(ctx, state)
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return nil, err
+		}
+	}
+
+	if time.CanUpgradeToBellatrix(state.Slot()) {
+		state, err = execution.UpgradeToBellatrix(state)
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return nil, err
+		}
+	}
+
+	if time.CanUpgradeToCapella(state.Slot()) {
+		state, err = capella.UpgradeToCapella(state)
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return nil, err
+		}
+	}
+
+	if time.CanUpgradeToDeneb(state.Slot()) {
+		state, err = deneb.UpgradeToDeneb(state)
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return nil, err
+		}
+	}
+	return state, nil
+}
+
 // VerifyOperationLengths verifies that block operation lengths are valid.
 func VerifyOperationLengths(_ context.Context, state state.BeaconState, b interfaces.ReadOnlySignedBeaconBlock) (state.BeaconState, error) {
 	if err := blocks.BeaconBlockIsNil(b); err != nil {
--- a/beacon-chain/core/transition/transition_no_verify_sig.go
+++ b/beacon-chain/core/transition/transition_no_verify_sig.go
@@ -256,7 +256,7 @@ func ProcessOperationsNoVerifyAttsSigs(
 		if err != nil {
 			return nil, err
 		}
-	case version.Altair, version.Bellatrix, version.Capella:
+	case version.Altair, version.Bellatrix, version.Capella, version.Deneb:
 		state, err = altairOperations(ctx, state, signedBeaconBlock)
 		if err != nil {
 			return nil, err
--- a/beacon-chain/core/transition/transition_test.go
+++ b/beacon-chain/core/transition/transition_test.go
@@ -629,6 +629,20 @@ func TestProcessSlots_ThroughBellatrixEpoch(t *testing.T) {
 	require.Equal(t, params.BeaconConfig().SlotsPerEpoch*10, st.Slot())
 }

+func TestProcessSlots_ThroughDenebEpoch(t *testing.T) {
+	transition.SkipSlotCache.Disable()
+	params.SetupTestConfigCleanup(t)
+	conf := params.BeaconConfig()
+	conf.DenebForkEpoch = 5
+	params.OverrideBeaconConfig(conf)
+
+	st, _ := util.DeterministicGenesisStateCapella(t, params.BeaconConfig().MaxValidatorsPerCommittee)
+	st, err := transition.ProcessSlots(context.Background(), st, params.BeaconConfig().SlotsPerEpoch*10)
+	require.NoError(t, err)
+	require.Equal(t, version.Deneb, st.Version())
+	require.Equal(t, params.BeaconConfig().SlotsPerEpoch*10, st.Slot())
+}
+
 func TestProcessSlotsUsingNextSlotCache(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 1)
 	r := []byte{'a'}
--- a/beacon-chain/core/validators/validator_test.go
+++ b/beacon-chain/core/validators/validator_test.go
@@ -150,7 +150,7 @@ func TestSlashValidator_OK(t *testing.T) {

 	maxBalance := params.BeaconConfig().MaxEffectiveBalance
 	slashedBalance := state.Slashings()[state.Slot().Mod(uint64(params.BeaconConfig().EpochsPerSlashingsVector))]
-	assert.Equal(t, maxBalance, slashedBalance, "Slashed balance isnt the expected amount")
+	assert.Equal(t, maxBalance, slashedBalance, "Slashed balance isn't the expected amount")

 	whistleblowerReward := slashedBalance / params.BeaconConfig().WhistleBlowerRewardQuotient
 	bal, err := state.BalanceAtIndex(proposer)
--- a/beacon-chain/db/iface/interface.go
+++ b/beacon-chain/db/iface/interface.go
@@ -54,6 +54,11 @@ type ReadOnlyDatabase interface {
 	// Fee recipients operations.
 	FeeRecipientByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (common.Address, error)
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
+
+	// Blob operations.
+	BlobSidecarsByRoot(ctx context.Context, beaconBlockRoot [32]byte, indices ...uint64) ([]*ethpb.BlobSidecar, error)
+	BlobSidecarsBySlot(ctx context.Context, slot primitives.Slot, indices ...uint64) ([]*ethpb.BlobSidecar, error)
+
 	// origin checkpoint sync support
 	OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
 	BackfillBlockRoot(ctx context.Context) ([32]byte, error)
@@ -89,6 +94,10 @@ type NoHeadAccessDatabase interface {
 	SaveFeeRecipientsByValidatorIDs(ctx context.Context, ids []primitives.ValidatorIndex, addrs []common.Address) error
 	SaveRegistrationsByValidatorIDs(ctx context.Context, ids []primitives.ValidatorIndex, regs []*ethpb.ValidatorRegistrationV1) error

+	// Blob operations.
+	SaveBlobSidecar(ctx context.Context, sidecars []*ethpb.BlobSidecar) error
+	DeleteBlobSidecar(ctx context.Context, beaconBlockRoot [32]byte) error
+
 	CleanUpDirtyStates(ctx context.Context, slotsPerArchivedPoint primitives.Slot) error
 }

--- a/beacon-chain/db/kv/BUILD.bazel
+++ b/beacon-chain/db/kv/BUILD.bazel
@@ -5,6 +5,7 @@ go_library(
    srcs = [
        "archived_point.go",
        "backup.go",
+        "blob.go",
        "blocks.go",
        "checkpoint.go",
        "deposit_contract.go",
@@ -38,6 +39,7 @@ go_library(
        "//beacon-chain/state/genesis:go_default_library",
        "//beacon-chain/state/state-native: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",
@@ -74,6 +76,7 @@ go_test(
    srcs = [
        "archived_point_test.go",
        "backup_test.go",
+        "blob_test.go",
        "blocks_test.go",
        "checkpoint_test.go",
        "deposit_contract_test.go",
@@ -110,6 +113,7 @@ go_test(
        "//proto/prysm/v1alpha1:go_default_library",
        "//proto/testing:go_default_library",
        "//testing/assert:go_default_library",
+        "//testing/assertions:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
--- a/beacon-chain/db/kv/blob.go
+++ b/beacon-chain/db/kv/blob.go
@@ -0,0 +1,253 @@
+package kv
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"sort"
+
+	"github.com/pkg/errors"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	types "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	bolt "go.etcd.io/bbolt"
+	"go.opencensus.io/trace"
+)
+
+// SaveBlobSidecar saves the blobs for a given epoch in the sidecar bucket. When we receive a blob:
+//
+//  1. Convert slot using a modulo operator to [0, maxSlots] where maxSlots = MAX_BLOB_EPOCHS*SLOTS_PER_EPOCH
+//
+//  2. Compute key for blob as bytes(slot_to_rotating_buffer(blob.slot)) ++ bytes(blob.slot) ++ blob.block_root
+//
+//  3. Begin the save algorithm:  If the incoming blob has a slot bigger than the saved slot at the spot
+//     in the rotating keys buffer, we overwrite all elements for that slot.
+func (s *Store) SaveBlobSidecar(ctx context.Context, scs []*ethpb.BlobSidecar) error {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.SaveBlobSidecar")
+	defer span.End()
+
+	sortSideCars(scs)
+	if err := s.verifySideCars(scs); err != nil {
+		return err
+	}
+
+	slot := scs[0].Slot
+	return s.db.Update(func(tx *bolt.Tx) error {
+		encodedBlobSidecar, err := encode(ctx, &ethpb.BlobSidecars{Sidecars: scs})
+		if err != nil {
+			return err
+		}
+		bkt := tx.Bucket(blobsBucket)
+		c := bkt.Cursor()
+		newKey := blobSidecarKey(scs[0])
+		rotatingBufferPrefix := newKey[0:8]
+		var replacingKey []byte
+		for k, _ := c.Seek(rotatingBufferPrefix); bytes.HasPrefix(k, rotatingBufferPrefix); k, _ = c.Next() {
+			if len(k) != 0 {
+				replacingKey = k
+				oldSlotBytes := replacingKey[8:16]
+				oldSlot := bytesutil.BytesToSlotBigEndian(oldSlotBytes)
+				if oldSlot >= slot {
+					return fmt.Errorf("attempted to save blob with slot %d but already have older blob with slot %d", slot, oldSlot)
+				}
+				break
+			}
+		}
+		// If there is no element stored at blob.slot % MAX_SLOTS_TO_PERSIST_BLOBS, then we simply
+		// store the blob by key and exit early.
+		if len(replacingKey) != 0 {
+			if err := bkt.Delete(replacingKey); err != nil {
+				log.WithError(err).Warnf("Could not delete blob with key %#x", replacingKey)
+			}
+		}
+		return bkt.Put(newKey, encodedBlobSidecar)
+	})
+}
+
+// verifySideCars ensures that all sidecars have the same slot, parent root, block root, and proposer index.
+// It also ensures that indices are sequential and start at 0 and no more than MAX_BLOB_EPOCHS.
+func (s *Store) verifySideCars(scs []*ethpb.BlobSidecar) error {
+	if len(scs) == 0 {
+		return errors.New("nil or empty blob sidecars")
+	}
+	if uint64(len(scs)) > fieldparams.MaxBlobsPerBlock {
+		return fmt.Errorf("too many sidecars: %d > %d", len(scs), fieldparams.MaxBlobsPerBlock)
+	}
+
+	sl := scs[0].Slot
+	pr := scs[0].BlockParentRoot
+	r := scs[0].BlockRoot
+	p := scs[0].ProposerIndex
+
+	for i, sc := range scs {
+		if sc.Slot != sl {
+			return fmt.Errorf("sidecar slot mismatch: %d != %d", sc.Slot, sl)
+		}
+		if !bytes.Equal(sc.BlockParentRoot, pr) {
+			return fmt.Errorf("sidecar parent root mismatch: %x != %x", sc.BlockParentRoot, pr)
+		}
+		if !bytes.Equal(sc.BlockRoot, r) {
+			return fmt.Errorf("sidecar root mismatch: %x != %x", sc.BlockRoot, r)
+		}
+		if sc.ProposerIndex != p {
+			return fmt.Errorf("sidecar proposer index mismatch: %d != %d", sc.ProposerIndex, p)
+		}
+		if sc.Index != uint64(i) {
+			return fmt.Errorf("sidecar index mismatch: %d != %d", sc.Index, i)
+		}
+	}
+	return nil
+}
+
+// sortSideCars sorts the sidecars by their index.
+func sortSideCars(scs []*ethpb.BlobSidecar) {
+	sort.Slice(scs, func(i, j int) bool {
+		return scs[i].Index < scs[j].Index
+	})
+}
+
+// BlobSidecarsByRoot retrieves the blobs for the given beacon block root.
+// If the `indices` argument is omitted, all blobs for the root will be returned.
+// Otherwise, the result will be filtered to only include the specified indices.
+// An error will result if an invalid index is specified.
+// The bucket size is bounded by 131072 entries. That's the most blobs a node will keep before rotating it out.
+func (s *Store) BlobSidecarsByRoot(ctx context.Context, root [32]byte, indices ...uint64) ([]*ethpb.BlobSidecar, error) {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.BlobSidecarsByRoot")
+	defer span.End()
+
+	var enc []byte
+	if err := s.db.View(func(tx *bolt.Tx) error {
+		c := tx.Bucket(blobsBucket).Cursor()
+		// Bucket size is bounded and bolt cursors are fast. Moreover, a thin caching layer can be added.
+		for k, v := c.First(); k != nil; k, v = c.Next() {
+			if bytes.HasSuffix(k, root[:]) {
+				enc = v
+				break
+			}
+		}
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+	if enc == nil {
+		return nil, ErrNotFound
+	}
+	sc := &ethpb.BlobSidecars{}
+	if err := decode(ctx, enc, sc); err != nil {
+		return nil, err
+	}
+
+	return filterForIndices(sc, indices...)
+}
+
+func filterForIndices(sc *ethpb.BlobSidecars, indices ...uint64) ([]*ethpb.BlobSidecar, error) {
+	if len(indices) == 0 {
+		return sc.Sidecars, nil
+	}
+	// This loop assumes that the BlobSidecars value stores the complete set of blobs for a block
+	// in ascending order from eg 0..3, without gaps. This allows us to assume the indices argument
+	// maps 1:1 with indices in the BlobSidecars storage object.
+	maxIdx := uint64(len(sc.Sidecars)) - 1
+	sidecars := make([]*ethpb.BlobSidecar, len(indices))
+	for i, idx := range indices {
+		if idx > maxIdx {
+			return nil, errors.Wrapf(ErrNotFound, "BlobSidecars missing index: index %d", idx)
+		}
+		sidecars[i] = sc.Sidecars[idx]
+	}
+	return sidecars, nil
+}
+
+// BlobSidecarsBySlot retrieves BlobSidecars for the given slot.
+// If the `indices` argument is omitted, all blobs for the root will be returned.
+// Otherwise, the result will be filtered to only include the specified indices.
+// An error will result if an invalid index is specified.
+// The bucket size is bounded by 131072 entries. That's the most blobs a node will keep before rotating it out.
+func (s *Store) BlobSidecarsBySlot(ctx context.Context, slot types.Slot, indices ...uint64) ([]*ethpb.BlobSidecar, error) {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.BlobSidecarsBySlot")
+	defer span.End()
+
+	var enc []byte
+	sk := slotKey(slot)
+	if err := s.db.View(func(tx *bolt.Tx) error {
+		c := tx.Bucket(blobsBucket).Cursor()
+		// Bucket size is bounded and bolt cursors are fast. Moreover, a thin caching layer can be added.
+		for k, v := c.Seek(sk); bytes.HasPrefix(k, sk); k, _ = c.Next() {
+			slotInKey := bytesutil.BytesToSlotBigEndian(k[8:16])
+			if slotInKey == slot {
+				enc = v
+				break
+			}
+		}
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+	if enc == nil {
+		return nil, ErrNotFound
+	}
+	sc := &ethpb.BlobSidecars{}
+	if err := decode(ctx, enc, sc); err != nil {
+		return nil, err
+	}
+
+	return filterForIndices(sc, indices...)
+}
+
+// DeleteBlobSidecar returns true if the blobs are in the db.
+func (s *Store) DeleteBlobSidecar(ctx context.Context, beaconBlockRoot [32]byte) error {
+	_, span := trace.StartSpan(ctx, "BeaconDB.DeleteBlobSidecar")
+	defer span.End()
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(blobsBucket)
+		c := bkt.Cursor()
+		for k, _ := c.First(); k != nil; k, _ = c.Next() {
+			if bytes.HasSuffix(k, beaconBlockRoot[:]) {
+				if err := bkt.Delete(k); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	})
+}
+
+// We define a blob sidecar key as: bytes(slot_to_rotating_buffer(blob.slot)) ++ bytes(blob.slot) ++ blob.block_root
+// where slot_to_rotating_buffer(slot) = slot % MAX_SLOTS_TO_PERSIST_BLOBS.
+func blobSidecarKey(blob *ethpb.BlobSidecar) []byte {
+	key := slotKey(blob.Slot)
+	key = append(key, bytesutil.SlotToBytesBigEndian(blob.Slot)...)
+	key = append(key, blob.BlockRoot...)
+	return key
+}
+
+func slotKey(slot types.Slot) []byte {
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	maxEpochsToPersistBlobs := params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest
+	maxSlotsToPersistBlobs := types.Slot(maxEpochsToPersistBlobs.Mul(uint64(slotsPerEpoch)))
+	return bytesutil.SlotToBytesBigEndian(slot.ModSlot(maxSlotsToPersistBlobs))
+}
+
+func checkEpochsForBlobSidecarsRequestBucket(db *bolt.DB) error {
+	if err := db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket(epochsForBlobSidecarsRequestBucket)
+		k := []byte("epoch-key")
+		v := b.Get(k)
+		if v == nil {
+			if err := b.Put(k, bytesutil.Uint64ToBytesBigEndian(uint64(params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest))); err != nil {
+				return err
+			}
+			return nil
+		}
+		e := bytesutil.BytesToUint64BigEndian(v)
+		if e != uint64(params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest) {
+			return fmt.Errorf("epochs for blobs request value in DB %d does not match config value %d", e, params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest)
+		}
+		return nil
+	}); err != nil {
+		return err
+	}
+	return nil
+}
--- a/beacon-chain/db/kv/blob_test.go
+++ b/beacon-chain/db/kv/blob_test.go
@@ -0,0 +1,317 @@
+package kv
+
+import (
+	"context"
+	"crypto/rand"
+	"fmt"
+	"testing"
+
+	"github.com/pkg/errors"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/assertions"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	bolt "go.etcd.io/bbolt"
+)
+
+func equalBlobSlices(expect []*ethpb.BlobSidecar, got []*ethpb.BlobSidecar) error {
+	if len(expect) != len(got) {
+		return fmt.Errorf("mismatched lengths, expect=%d, got=%d", len(expect), len(got))
+	}
+	for i := 0; i < len(expect); i++ {
+		es := expect[i]
+		gs := got[i]
+		var e string
+		assertions.DeepEqual(assertions.SprintfAssertionLoggerFn(&e), es, gs)
+		if e != "" {
+			return errors.New(e)
+		}
+	}
+	return nil
+}
+
+func TestStore_BlobSidecars(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("empty", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, 0)
+		require.ErrorContains(t, "nil or empty blob sidecars", db.SaveBlobSidecar(ctx, scs))
+	})
+	t.Run("empty by root", func(t *testing.T) {
+		db := setupDB(t)
+		got, err := db.BlobSidecarsByRoot(ctx, [32]byte{})
+		require.ErrorIs(t, ErrNotFound, err)
+		require.Equal(t, 0, len(got))
+	})
+	t.Run("empty by slot", func(t *testing.T) {
+		db := setupDB(t)
+		got, err := db.BlobSidecarsBySlot(ctx, 1)
+		require.ErrorIs(t, ErrNotFound, err)
+		require.Equal(t, 0, len(got))
+	})
+	t.Run("save and retrieve by root (one)", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, 1)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, 1, len(scs))
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot))
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+	})
+	t.Run("save and retrieve by root (max)", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot))
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+	})
+	t.Run("save and retrieve valid subset by root", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+
+		// we'll request indices 0 and 3, so make a slice with those indices for comparison
+		expect := make([]*ethpb.BlobSidecar, 2)
+		expect[0] = scs[0]
+		expect[1] = scs[3]
+
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot), 0, 3)
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(expect, got))
+		require.Equal(t, uint64(0), got[0].Index)
+		require.Equal(t, uint64(3), got[1].Index)
+	})
+	t.Run("error for invalid index when retrieving by root", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot), uint64(len(scs)))
+		require.ErrorIs(t, err, ErrNotFound)
+		require.Equal(t, 0, len(got))
+	})
+	t.Run("save and retrieve by slot (one)", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, 1)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, 1, len(scs))
+		got, err := db.BlobSidecarsBySlot(ctx, scs[0].Slot)
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+	})
+	t.Run("save and retrieve by slot (max)", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+		got, err := db.BlobSidecarsBySlot(ctx, scs[0].Slot)
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+	})
+	t.Run("save and retrieve valid subset by slot", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+
+		// we'll request indices 0 and 3, so make a slice with those indices for comparison
+		expect := make([]*ethpb.BlobSidecar, 2)
+		expect[0] = scs[0]
+		expect[1] = scs[3]
+
+		got, err := db.BlobSidecarsBySlot(ctx, scs[0].Slot, 0, 3)
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(expect, got))
+
+		require.Equal(t, uint64(0), got[0].Index)
+		require.Equal(t, uint64(3), got[1].Index)
+	})
+	t.Run("error for invalid index when retrieving by slot", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+
+		got, err := db.BlobSidecarsBySlot(ctx, scs[0].Slot, uint64(len(scs)))
+		require.ErrorIs(t, err, ErrNotFound)
+		require.Equal(t, 0, len(got))
+	})
+	t.Run("delete works", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot))
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+		require.NoError(t, db.DeleteBlobSidecar(ctx, bytesutil.ToBytes32(scs[0].BlockRoot)))
+		got, err = db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot))
+		require.ErrorIs(t, ErrNotFound, err)
+		require.Equal(t, 0, len(got))
+	})
+	t.Run("saving a blob with older slot", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(scs[0].BlockRoot))
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+		require.ErrorContains(t, "but already have older blob with slot", db.SaveBlobSidecar(ctx, scs))
+	})
+	t.Run("saving a new blob for rotation", func(t *testing.T) {
+		db := setupDB(t)
+		scs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		require.NoError(t, db.SaveBlobSidecar(ctx, scs))
+		require.Equal(t, int(fieldparams.MaxBlobsPerBlock), len(scs))
+		oldBlockRoot := scs[0].BlockRoot
+		got, err := db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(oldBlockRoot))
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(scs, got))
+
+		newScs := generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock)
+		newRetentionSlot := primitives.Slot(params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest.Mul(uint64(params.BeaconConfig().SlotsPerEpoch)))
+		for _, sc := range newScs {
+			sc.Slot = sc.Slot + newRetentionSlot
+		}
+		require.NoError(t, db.SaveBlobSidecar(ctx, newScs))
+
+		_, err = db.BlobSidecarsBySlot(ctx, 100)
+		require.ErrorIs(t, ErrNotFound, err)
+
+		got, err = db.BlobSidecarsByRoot(ctx, bytesutil.ToBytes32(newScs[0].BlockRoot))
+		require.NoError(t, err)
+		require.NoError(t, equalBlobSlices(newScs, got))
+	})
+}
+
+func generateBlobSidecars(t *testing.T, n uint64) []*ethpb.BlobSidecar {
+	blobSidecars := make([]*ethpb.BlobSidecar, n)
+	for i := uint64(0); i < n; i++ {
+		blobSidecars[i] = generateBlobSidecar(t, i)
+	}
+	return blobSidecars
+}
+
+func generateBlobSidecar(t *testing.T, index uint64) *ethpb.BlobSidecar {
+	blob := make([]byte, 131072)
+	_, err := rand.Read(blob)
+	require.NoError(t, err)
+	kzgCommitment := make([]byte, 48)
+	_, err = rand.Read(kzgCommitment)
+	require.NoError(t, err)
+	kzgProof := make([]byte, 48)
+	_, err = rand.Read(kzgProof)
+	require.NoError(t, err)
+
+	return &ethpb.BlobSidecar{
+		BlockRoot:       bytesutil.PadTo([]byte{'a'}, 32),
+		Index:           index,
+		Slot:            100,
+		BlockParentRoot: bytesutil.PadTo([]byte{'b'}, 32),
+		ProposerIndex:   101,
+		Blob:            blob,
+		KzgCommitment:   kzgCommitment,
+		KzgProof:        kzgProof,
+	}
+}
+
+func TestStore_verifySideCars(t *testing.T) {
+	s := setupDB(t)
+	tests := []struct {
+		name  string
+		scs   []*ethpb.BlobSidecar
+		error string
+	}{
+		{name: "empty", scs: []*ethpb.BlobSidecar{}, error: "nil or empty blob sidecars"},
+		{name: "too many sidecars", scs: generateBlobSidecars(t, fieldparams.MaxBlobsPerBlock+1), error: "too many sidecars: 7 > 6"},
+		{name: "invalid slot", scs: []*ethpb.BlobSidecar{{Slot: 1}, {Slot: 2}}, error: "sidecar slot mismatch: 2 != 1"},
+		{name: "invalid proposer index", scs: []*ethpb.BlobSidecar{{ProposerIndex: 1}, {ProposerIndex: 2}}, error: "sidecar proposer index mismatch: 2 != 1"},
+		{name: "invalid root", scs: []*ethpb.BlobSidecar{{BlockRoot: []byte{1}}, {BlockRoot: []byte{2}}}, error: "sidecar root mismatch: 02 != 01"},
+		{name: "invalid parent root", scs: []*ethpb.BlobSidecar{{BlockParentRoot: []byte{1}}, {BlockParentRoot: []byte{2}}}, error: "sidecar parent root mismatch: 02 != 01"},
+		{name: "invalid side index", scs: []*ethpb.BlobSidecar{{Index: 0}, {Index: 0}}, error: "sidecar index mismatch: 0 != 1"},
+		{name: "happy path", scs: []*ethpb.BlobSidecar{{Index: 0}, {Index: 1}}, error: ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := s.verifySideCars(tt.scs)
+			if tt.error != "" {
+				require.Equal(t, tt.error, err.Error())
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestStore_sortSidecars(t *testing.T) {
+	scs := []*ethpb.BlobSidecar{
+		{Index: 6},
+		{Index: 4},
+		{Index: 2},
+		{Index: 1},
+		{Index: 3},
+		{Index: 5},
+		{},
+	}
+	sortSideCars(scs)
+	for i := 0; i < len(scs)-1; i++ {
+		require.Equal(t, uint64(i), scs[i].Index)
+	}
+}
+
+func BenchmarkStore_BlobSidecarsByRoot(b *testing.B) {
+	s := setupDB(b)
+	ctx := context.Background()
+	require.NoError(b, s.SaveBlobSidecar(ctx, []*ethpb.BlobSidecar{
+		{BlockRoot: bytesutil.PadTo([]byte{'a'}, 32), Slot: 0},
+	}))
+
+	err := s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(blobsBucket)
+		for i := 1; i < 131071; i++ {
+			r := make([]byte, 32)
+			_, err := rand.Read(r)
+			require.NoError(b, err)
+			scs := []*ethpb.BlobSidecar{
+				{BlockRoot: r, Slot: primitives.Slot(i)},
+			}
+			k := blobSidecarKey(scs[0])
+			encodedBlobSidecar, err := encode(ctx, &ethpb.BlobSidecars{Sidecars: scs})
+			require.NoError(b, err)
+			require.NoError(b, bkt.Put(k, encodedBlobSidecar))
+		}
+		return nil
+	})
+	require.NoError(b, err)
+
+	require.NoError(b, s.SaveBlobSidecar(ctx, []*ethpb.BlobSidecar{
+		{BlockRoot: bytesutil.PadTo([]byte{'b'}, 32), Slot: 131071},
+	}))
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := s.BlobSidecarsByRoot(ctx, [32]byte{'b'})
+		require.NoError(b, err)
+	}
+}
+
+func Test_checkEpochsForBlobSidecarsRequestBucket(t *testing.T) {
+	dbStore := setupDB(t)
+
+	require.NoError(t, checkEpochsForBlobSidecarsRequestBucket(dbStore.db)) // First write
+	require.NoError(t, checkEpochsForBlobSidecarsRequestBucket(dbStore.db)) // First check
+
+	nConfig := params.BeaconNetworkConfig()
+	nConfig.MinEpochsForBlobsSidecarsRequest = 42069
+	params.OverrideBeaconNetworkConfig(nConfig)
+	require.ErrorContains(t, "epochs for blobs request value in DB 4096 does not match config value 42069", checkEpochsForBlobSidecarsRequestBucket(dbStore.db))
+}
--- a/beacon-chain/db/kv/blocks.go
+++ b/beacon-chain/db/kv/blocks.go
@@ -818,6 +818,16 @@ func unmarshalBlock(_ context.Context, enc []byte) (interfaces.ReadOnlySignedBea
 		if err := rawBlock.UnmarshalSSZ(enc[len(capellaBlindKey):]); err != nil {
 			return nil, errors.Wrap(err, "could not unmarshal blinded Capella block")
 		}
+	case hasDenebKey(enc):
+		rawBlock = &ethpb.SignedBeaconBlockDeneb{}
+		if err := rawBlock.UnmarshalSSZ(enc[len(denebKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Deneb block")
+		}
+	case hasDenebBlindKey(enc):
+		rawBlock = &ethpb.SignedBlindedBeaconBlockDeneb{}
+		if err := rawBlock.UnmarshalSSZ(enc[len(denebBlindKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal blinded Deneb block")
+		}
 	default:
 		// Marshal block bytes to phase 0 beacon block.
 		rawBlock = &ethpb.SignedBeaconBlock{}
@@ -854,6 +864,8 @@ func marshalBlockFull(
 		return nil, err
 	}
 	switch blk.Version() {
+	case version.Deneb:
+		return snappy.Encode(nil, append(denebKey, encodedBlock...)), nil
 	case version.Capella:
 		return snappy.Encode(nil, append(capellaKey, encodedBlock...)), nil
 	case version.Bellatrix:
@@ -888,6 +900,8 @@ func marshalBlockBlinded(
 		return nil, errors.Wrap(err, "could not marshal blinded block")
 	}
 	switch blk.Version() {
+	case version.Deneb:
+		return snappy.Encode(nil, append(denebBlindKey, encodedBlock...)), nil
 	case version.Capella:
 		return snappy.Encode(nil, append(capellaBlindKey, encodedBlock...)), nil
 	case version.Bellatrix:
--- a/beacon-chain/db/kv/blocks_test.go
+++ b/beacon-chain/db/kv/blocks_test.go
@@ -90,6 +90,40 @@ var blockTests = []struct {
 			return blocks.NewSignedBeaconBlock(b)
 		},
 	},
+	{
+		name: "deneb",
+		newBlock: func(slot primitives.Slot, root []byte) (interfaces.ReadOnlySignedBeaconBlock, error) {
+			b := util.NewBeaconBlockDeneb()
+			b.Block.Slot = slot
+			if root != nil {
+				b.Block.ParentRoot = root
+				b.Block.Body.BlobKzgCommitments = [][]byte{
+					bytesutil.PadTo([]byte{0x01}, 48),
+					bytesutil.PadTo([]byte{0x02}, 48),
+					bytesutil.PadTo([]byte{0x03}, 48),
+					bytesutil.PadTo([]byte{0x04}, 48),
+				}
+			}
+			return blocks.NewSignedBeaconBlock(b)
+		},
+	},
+	{
+		name: "deneb blind",
+		newBlock: func(slot primitives.Slot, root []byte) (interfaces.ReadOnlySignedBeaconBlock, error) {
+			b := util.NewBlindedBeaconBlockDeneb()
+			b.Block.Slot = slot
+			if root != nil {
+				b.Block.ParentRoot = root
+				b.Block.Body.BlobKzgCommitments = [][]byte{
+					bytesutil.PadTo([]byte{0x05}, 48),
+					bytesutil.PadTo([]byte{0x06}, 48),
+					bytesutil.PadTo([]byte{0x07}, 48),
+					bytesutil.PadTo([]byte{0x08}, 48),
+				}
+			}
+			return blocks.NewSignedBeaconBlock(b)
+		},
+	},
 }

 func TestStore_SaveBackfillBlockRoot(t *testing.T) {
@@ -359,6 +393,10 @@ func TestStore_BlocksCRUD_NoCache(t *testing.T) {
 				wanted, err = blk.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := blk.PbDenebBlock(); err == nil {
+				wanted, err = blk.ToBlinded()
+				require.NoError(t, err)
+			}
 			wantedPb, err := wanted.Proto()
 			require.NoError(t, err)
 			retrievedPb, err := retrievedBlock.Proto()
@@ -543,7 +581,7 @@ func TestStore_Blocks_Retrieve_SlotRangeWithStep(t *testing.T) {
 			require.NoError(t, err)
 			assert.Equal(t, 150, len(retrieved))
 			for _, b := range retrieved {
-				assert.Equal(t, primitives.Slot(0), (b.Block().Slot()-100)%step, "Unexpect block slot %d", b.Block().Slot())
+				assert.Equal(t, primitives.Slot(0), (b.Block().Slot()-100)%step, "Unexpected block slot %d", b.Block().Slot())
 			}
 		})
 	}
@@ -582,6 +620,10 @@ func TestStore_SaveBlock_CanGetHighestAt(t *testing.T) {
 				wanted, err = wanted.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := block1.PbDenebBlock(); err == nil {
+				wanted, err = wanted.ToBlinded()
+				require.NoError(t, err)
+			}
 			wantedPb, err := wanted.Proto()
 			require.NoError(t, err)
 			bPb, err := b.Proto()
@@ -604,6 +646,10 @@ func TestStore_SaveBlock_CanGetHighestAt(t *testing.T) {
 				wanted2, err = block2.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := block2.PbDenebBlock(); err == nil {
+				wanted2, err = block2.ToBlinded()
+				require.NoError(t, err)
+			}
 			wanted2Pb, err := wanted2.Proto()
 			require.NoError(t, err)
 			bPb, err = b.Proto()
@@ -626,6 +672,10 @@ func TestStore_SaveBlock_CanGetHighestAt(t *testing.T) {
 				wanted, err = wanted.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := block3.PbDenebBlock(); err == nil {
+				wanted, err = wanted.ToBlinded()
+				require.NoError(t, err)
+			}
 			wantedPb, err = wanted.Proto()
 			require.NoError(t, err)
 			bPb, err = b.Proto()
@@ -666,6 +716,10 @@ func TestStore_GenesisBlock_CanGetHighestAt(t *testing.T) {
 				wanted, err = block1.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := block1.PbDenebBlock(); err == nil {
+				wanted, err = block1.ToBlinded()
+				require.NoError(t, err)
+			}
 			wantedPb, err := wanted.Proto()
 			require.NoError(t, err)
 			bPb, err := b.Proto()
@@ -687,6 +741,10 @@ func TestStore_GenesisBlock_CanGetHighestAt(t *testing.T) {
 				wanted, err = genesisBlock.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := genesisBlock.PbDenebBlock(); err == nil {
+				wanted, err = genesisBlock.ToBlinded()
+				require.NoError(t, err)
+			}
 			wantedPb, err = wanted.Proto()
 			require.NoError(t, err)
 			bPb, err = b.Proto()
@@ -708,6 +766,10 @@ func TestStore_GenesisBlock_CanGetHighestAt(t *testing.T) {
 				wanted, err = genesisBlock.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := genesisBlock.PbDenebBlock(); err == nil {
+				wanted, err = genesisBlock.ToBlinded()
+				require.NoError(t, err)
+			}
 			wantedPb, err = wanted.Proto()
 			require.NoError(t, err)
 			bPb, err = b.Proto()
@@ -808,6 +870,10 @@ func TestStore_BlocksBySlot_BlockRootsBySlot(t *testing.T) {
 				wanted, err = b1.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := b1.PbDenebBlock(); err == nil {
+				wanted, err = b1.ToBlinded()
+				require.NoError(t, err)
+			}
 			retrieved0Pb, err := retrievedBlocks[0].Proto()
 			require.NoError(t, err)
 			wantedPb, err := wanted.Proto()
@@ -828,6 +894,10 @@ func TestStore_BlocksBySlot_BlockRootsBySlot(t *testing.T) {
 				wanted, err = b2.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := b2.PbDenebBlock(); err == nil {
+				wanted, err = b2.ToBlinded()
+				require.NoError(t, err)
+			}
 			retrieved0Pb, err = retrievedBlocks[0].Proto()
 			require.NoError(t, err)
 			wantedPb, err = wanted.Proto()
@@ -842,6 +912,10 @@ func TestStore_BlocksBySlot_BlockRootsBySlot(t *testing.T) {
 				wanted, err = b3.ToBlinded()
 				require.NoError(t, err)
 			}
+			if _, err := b3.PbDenebBlock(); err == nil {
+				wanted, err = b3.ToBlinded()
+				require.NoError(t, err)
+			}
 			retrieved1Pb, err := retrievedBlocks[1].Proto()
 			require.NoError(t, err)
 			wantedPb, err = wanted.Proto()
--- a/beacon-chain/db/kv/key.go
+++ b/beacon-chain/db/kv/key.go
@@ -37,3 +37,17 @@ func hasCapellaBlindKey(enc []byte) bool {
 	}
 	return bytes.Equal(enc[:len(capellaBlindKey)], capellaBlindKey)
 }
+
+func hasDenebKey(enc []byte) bool {
+	if len(denebKey) >= len(enc) {
+		return false
+	}
+	return bytes.Equal(enc[:len(denebKey)], denebKey)
+}
+
+func hasDenebBlindKey(enc []byte) bool {
+	if len(denebBlindKey) >= len(enc) {
+		return false
+	}
+	return bytes.Equal(enc[:len(denebBlindKey)], denebBlindKey)
+}
--- a/beacon-chain/db/kv/kv.go
+++ b/beacon-chain/db/kv/kv.go
@@ -129,6 +129,9 @@ var Buckets = [][]byte{

 	feeRecipientBucket,
 	registrationBucket,
+
+	blobsBucket,
+	epochsForBlobSidecarsRequestBucket,
 }

 // NewKVStore initializes a new boltDB key-value store at the directory
@@ -199,6 +202,11 @@ func NewKVStore(ctx context.Context, dirPath string) (*Store, error) {
 	if err := kv.setupBlockStorageType(ctx); err != nil {
 		return nil, err
 	}
+
+	if err := checkEpochsForBlobSidecarsRequestBucket(boltDB); err != nil {
+		return nil, errors.Wrap(err, "failed to check epochs for blob sidecars request bucket")
+	}
+
 	return kv, nil
 }

--- a/beacon-chain/db/kv/migration_state_validators.go
+++ b/beacon-chain/db/kv/migration_state_validators.go
@@ -130,9 +130,15 @@ func performValidatorStateMigration(ctx context.Context, bar *progressbar.Progre
 				return err
 			}
 			item := enc
-			if hasAltairKey(item) {
+			switch {
+			case hasAltairKey(enc):
 				item = item[len(altairKey):]
+			case hasBellatrixKey(enc):
+				item = item[len(bellatrixKey):]
+			case hasCapellaKey(enc):
+				item = item[len(capellaKey):]
 			}
+
 			detector, err := detect.FromState(item)
 			if err != nil {
 				return err
@@ -165,9 +171,14 @@ func performValidatorStateMigration(ctx context.Context, bar *progressbar.Progre
 				return err
 			}
 			var stateBytes []byte
-			if hasAltairKey(enc) {
+			switch {
+			case hasAltairKey(enc):
 				stateBytes = snappy.Encode(nil, append(altairKey, rawObj...))
-			} else {
+			case hasBellatrixKey(enc):
+				stateBytes = snappy.Encode(nil, append(bellatrixKey, rawObj...))
+			case hasCapellaKey(enc):
+				stateBytes = snappy.Encode(nil, append(capellaKey, rawObj...))
+			default:
 				stateBytes = snappy.Encode(nil, rawObj)
 			}
 			if stateErr := stateBkt.Put(keys[index], stateBytes); stateErr != nil {
--- a/beacon-chain/db/kv/migration_state_validators_test.go
+++ b/beacon-chain/db/kv/migration_state_validators_test.go
@@ -313,3 +313,217 @@ func Test_migrateAltairStateValidators(t *testing.T) {
 		})
 	}
 }
+
+func Test_migrateBellatrixStateValidators(t *testing.T) {
+	tests := []struct {
+		name  string
+		setup func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator)
+		eval  func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator)
+	}{
+		{
+			name: "migrates validators and adds them to new buckets",
+			setup: func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator) {
+				// create some new buckets that should be present for this migration
+				err := dbStore.db.Update(func(tx *bbolt.Tx) error {
+					_, err := tx.CreateBucketIfNotExists(stateValidatorsBucket)
+					assert.NoError(t, err)
+					_, err = tx.CreateBucketIfNotExists(blockRootValidatorHashesBucket)
+					assert.NoError(t, err)
+					return nil
+				})
+				assert.NoError(t, err)
+			},
+			eval: func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator) {
+				// check whether the new buckets are present
+				err := dbStore.db.View(func(tx *bbolt.Tx) error {
+					valBkt := tx.Bucket(stateValidatorsBucket)
+					assert.NotNil(t, valBkt)
+					idxBkt := tx.Bucket(blockRootValidatorHashesBucket)
+					assert.NotNil(t, idxBkt)
+					return nil
+				})
+				assert.NoError(t, err)
+
+				// check if the migration worked
+				blockRoot := [32]byte{'A'}
+				rcvdState, err := dbStore.State(context.Background(), blockRoot)
+				assert.NoError(t, err)
+				require.DeepSSZEqual(t, rcvdState.ToProtoUnsafe(), state.ToProtoUnsafe(), "saved state with validators and retrieved state are not matching")
+
+				// find hashes of the validators that are set as part of the state
+				var hashes []byte
+				var individualHashes [][]byte
+				for _, val := range vals {
+					hash, hashErr := val.HashTreeRoot()
+					assert.NoError(t, hashErr)
+					hashes = append(hashes, hash[:]...)
+					individualHashes = append(individualHashes, hash[:])
+				}
+
+				// check if all the validators that were in the state, are stored properly in the validator bucket
+				pbState, err := state_native.ProtobufBeaconStateBellatrix(rcvdState.ToProtoUnsafe())
+				assert.NoError(t, err)
+				validatorsFoundCount := 0
+				for _, val := range pbState.Validators {
+					hash, hashErr := val.HashTreeRoot()
+					assert.NoError(t, hashErr)
+					found := false
+					for _, h := range individualHashes {
+						if bytes.Equal(hash[:], h) {
+							found = true
+						}
+					}
+					require.Equal(t, true, found)
+					validatorsFoundCount++
+				}
+				require.Equal(t, len(vals), validatorsFoundCount)
+
+				// check if the state validator indexes are stored properly
+				err = dbStore.db.View(func(tx *bbolt.Tx) error {
+					rcvdValhashBytes := tx.Bucket(blockRootValidatorHashesBucket).Get(blockRoot[:])
+					rcvdValHashes, sErr := snappy.Decode(nil, rcvdValhashBytes)
+					assert.NoError(t, sErr)
+					require.DeepEqual(t, hashes, rcvdValHashes)
+					return nil
+				})
+				assert.NoError(t, err)
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dbStore := setupDB(t)
+
+			// add a state with the given validators
+			vals := validators(10)
+			blockRoot := [32]byte{'A'}
+			st, _ := util.DeterministicGenesisStateBellatrix(t, 20)
+			err := st.SetFork(&v1alpha1.Fork{
+				PreviousVersion: params.BeaconConfig().AltairForkVersion,
+				CurrentVersion:  params.BeaconConfig().BellatrixForkVersion,
+				Epoch:           0,
+			})
+			require.NoError(t, err)
+			assert.NoError(t, st.SetSlot(100))
+			assert.NoError(t, st.SetValidators(vals))
+			assert.NoError(t, dbStore.SaveState(context.Background(), st, blockRoot))
+
+			// enable historical state representation flag to test this
+			resetCfg := features.InitWithReset(&features.Flags{
+				EnableHistoricalSpaceRepresentation: true,
+			})
+			defer resetCfg()
+
+			tt.setup(t, dbStore, st, vals)
+			assert.NoError(t, migrateStateValidators(context.Background(), dbStore.db), "migrateArchivedIndex(tx) error")
+			tt.eval(t, dbStore, st, vals)
+		})
+	}
+}
+
+func Test_migrateCapellaStateValidators(t *testing.T) {
+	tests := []struct {
+		name  string
+		setup func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator)
+		eval  func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator)
+	}{
+		{
+			name: "migrates validators and adds them to new buckets",
+			setup: func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator) {
+				// create some new buckets that should be present for this migration
+				err := dbStore.db.Update(func(tx *bbolt.Tx) error {
+					_, err := tx.CreateBucketIfNotExists(stateValidatorsBucket)
+					assert.NoError(t, err)
+					_, err = tx.CreateBucketIfNotExists(blockRootValidatorHashesBucket)
+					assert.NoError(t, err)
+					return nil
+				})
+				assert.NoError(t, err)
+			},
+			eval: func(t *testing.T, dbStore *Store, state state.BeaconState, vals []*v1alpha1.Validator) {
+				// check whether the new buckets are present
+				err := dbStore.db.View(func(tx *bbolt.Tx) error {
+					valBkt := tx.Bucket(stateValidatorsBucket)
+					assert.NotNil(t, valBkt)
+					idxBkt := tx.Bucket(blockRootValidatorHashesBucket)
+					assert.NotNil(t, idxBkt)
+					return nil
+				})
+				assert.NoError(t, err)
+
+				// check if the migration worked
+				blockRoot := [32]byte{'A'}
+				rcvdState, err := dbStore.State(context.Background(), blockRoot)
+				assert.NoError(t, err)
+				require.DeepSSZEqual(t, rcvdState.ToProtoUnsafe(), state.ToProtoUnsafe(), "saved state with validators and retrieved state are not matching")
+
+				// find hashes of the validators that are set as part of the state
+				var hashes []byte
+				var individualHashes [][]byte
+				for _, val := range vals {
+					hash, hashErr := val.HashTreeRoot()
+					assert.NoError(t, hashErr)
+					hashes = append(hashes, hash[:]...)
+					individualHashes = append(individualHashes, hash[:])
+				}
+
+				// check if all the validators that were in the state, are stored properly in the validator bucket
+				pbState, err := state_native.ProtobufBeaconStateCapella(rcvdState.ToProtoUnsafe())
+				assert.NoError(t, err)
+				validatorsFoundCount := 0
+				for _, val := range pbState.Validators {
+					hash, hashErr := val.HashTreeRoot()
+					assert.NoError(t, hashErr)
+					found := false
+					for _, h := range individualHashes {
+						if bytes.Equal(hash[:], h) {
+							found = true
+						}
+					}
+					require.Equal(t, true, found)
+					validatorsFoundCount++
+				}
+				require.Equal(t, len(vals), validatorsFoundCount)
+
+				// check if the state validator indexes are stored properly
+				err = dbStore.db.View(func(tx *bbolt.Tx) error {
+					rcvdValhashBytes := tx.Bucket(blockRootValidatorHashesBucket).Get(blockRoot[:])
+					rcvdValHashes, sErr := snappy.Decode(nil, rcvdValhashBytes)
+					assert.NoError(t, sErr)
+					require.DeepEqual(t, hashes, rcvdValHashes)
+					return nil
+				})
+				assert.NoError(t, err)
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dbStore := setupDB(t)
+
+			// add a state with the given validators
+			vals := validators(10)
+			blockRoot := [32]byte{'A'}
+			st, _ := util.DeterministicGenesisStateCapella(t, 20)
+			err := st.SetFork(&v1alpha1.Fork{
+				PreviousVersion: params.BeaconConfig().BellatrixForkVersion,
+				CurrentVersion:  params.BeaconConfig().CapellaForkVersion,
+				Epoch:           0,
+			})
+			require.NoError(t, err)
+			assert.NoError(t, st.SetSlot(100))
+			assert.NoError(t, st.SetValidators(vals))
+			assert.NoError(t, dbStore.SaveState(context.Background(), st, blockRoot))
+
+			// enable historical state representation flag to test this
+			resetCfg := features.InitWithReset(&features.Flags{
+				EnableHistoricalSpaceRepresentation: true,
+			})
+			defer resetCfg()
+
+			tt.setup(t, dbStore, st, vals)
+			assert.NoError(t, migrateStateValidators(context.Background(), dbStore.db), "migrateArchivedIndex(tx) error")
+			tt.eval(t, dbStore, st, vals)
+		})
+	}
+}
--- a/beacon-chain/db/kv/schema.go
+++ b/beacon-chain/db/kv/schema.go
@@ -46,6 +46,7 @@ var (
 	finalizedCheckpointKey     = []byte("finalized-checkpoint")
 	powchainDataKey            = []byte("powchain-data")
 	lastValidatedCheckpointKey = []byte("last-validated-checkpoint")
+	blobsBucket                = []byte("blobs")

 	// Below keys are used to identify objects are to be fork compatible.
 	// Objects that are only compatible with specific forks should be prefixed with such keys.
@@ -55,6 +56,9 @@ var (
 	capellaKey                 = []byte("capella")
 	capellaBlindKey            = []byte("blind-capella")
 	saveBlindedBeaconBlocksKey = []byte("save-blinded-beacon-blocks")
+	denebKey                   = []byte("deneb")
+	denebBlindKey              = []byte("blind-deneb")
+
 	// block root included in the beacon state used by weak subjectivity initial sync
 	originCheckpointBlockRootKey = []byte("origin-checkpoint-block-root")
 	// block root tracking the progress of backfill, or pointing at genesis if backfill has not been initiated
@@ -70,4 +74,7 @@ var (

 	// Migrations
 	migrationsBucket = []byte("migrations")
+
+	// Stores how long to keep the blob sidecars for.
+	epochsForBlobSidecarsRequestBucket = []byte("epochs-for-blob-sidecars-request")
 )
--- a/beacon-chain/db/kv/state.go
+++ b/beacon-chain/db/kv/state.go
@@ -229,34 +229,28 @@ func (s *Store) saveStatesEfficientInternal(ctx context.Context, tx *bolt.Tx, bl
 		// look at issue https://github.com/prysmaticlabs/prysm/issues/9262.
 		switch rawType := states[i].ToProtoUnsafe().(type) {
 		case *ethpb.BeaconState:
-			pbState, err := statenative.ProtobufBeaconStatePhase0(rawType)
+			pbState, err := getPhase0PbState(rawType)
 			if err != nil {
 				return err
 			}
-			if pbState == nil {
-				return errors.New("nil state")
-			}
 			valEntries := pbState.Validators
 			pbState.Validators = make([]*ethpb.Validator, 0)
 			encodedState, err := encode(ctx, pbState)
 			if err != nil {
 				return err
 			}
+			pbState.Validators = valEntries
 			if err := bucket.Put(rt[:], encodedState); err != nil {
 				return err
 			}
-			pbState.Validators = valEntries
 			if err := valIdxBkt.Put(rt[:], validatorKeys[i]); err != nil {
 				return err
 			}
 		case *ethpb.BeaconStateAltair:
-			pbState, err := statenative.ProtobufBeaconStateAltair(rawType)
+			pbState, err := getAltairPbState(rawType)
 			if err != nil {
 				return err
 			}
-			if pbState == nil {
-				return errors.New("nil state")
-			}
 			valEntries := pbState.Validators
 			pbState.Validators = make([]*ethpb.Validator, 0)
 			rawObj, err := pbState.MarshalSSZ()
@@ -272,13 +266,10 @@ func (s *Store) saveStatesEfficientInternal(ctx context.Context, tx *bolt.Tx, bl
 				return err
 			}
 		case *ethpb.BeaconStateBellatrix:
-			pbState, err := statenative.ProtobufBeaconStateBellatrix(rawType)
+			pbState, err := getBellatrixPbState(rawType)
 			if err != nil {
 				return err
 			}
-			if pbState == nil {
-				return errors.New("nil state")
-			}
 			valEntries := pbState.Validators
 			pbState.Validators = make([]*ethpb.Validator, 0)
 			rawObj, err := pbState.MarshalSSZ()
@@ -294,12 +285,28 @@ func (s *Store) saveStatesEfficientInternal(ctx context.Context, tx *bolt.Tx, bl
 				return err
 			}
 		case *ethpb.BeaconStateCapella:
-			pbState, err := statenative.ProtobufBeaconStateCapella(rawType)
+			pbState, err := getCapellaPbState(rawType)
 			if err != nil {
 				return err
 			}
-			if pbState == nil {
-				return errors.New("nil state")
+			valEntries := pbState.Validators
+			pbState.Validators = make([]*ethpb.Validator, 0)
+			rawObj, err := pbState.MarshalSSZ()
+			if err != nil {
+				return err
+			}
+			encodedState := snappy.Encode(nil, append(capellaKey, rawObj...))
+			if err := bucket.Put(rt[:], encodedState); err != nil {
+				return err
+			}
+			pbState.Validators = valEntries
+			if err := valIdxBkt.Put(rt[:], validatorKeys[i]); err != nil {
+				return err
+			}
+		case *ethpb.BeaconStateDeneb:
+			pbState, err := getDenebPbState(rawType)
+			if err != nil {
+				return err
 			}
 			valEntries := pbState.Validators
 			pbState.Validators = make([]*ethpb.Validator, 0)
@@ -323,6 +330,61 @@ func (s *Store) saveStatesEfficientInternal(ctx context.Context, tx *bolt.Tx, bl
 	return s.storeValidatorEntriesSeparately(ctx, tx, validatorsEntries)
 }

+func getPhase0PbState(rawState interface{}) (*ethpb.BeaconState, error) {
+	pbState, err := statenative.ProtobufBeaconStatePhase0(rawState)
+	if err != nil {
+		return nil, err
+	}
+	if pbState == nil {
+		return nil, errors.New("nil state")
+	}
+	return pbState, nil
+}
+
+func getAltairPbState(rawState interface{}) (*ethpb.BeaconStateAltair, error) {
+	pbState, err := statenative.ProtobufBeaconStateAltair(rawState)
+	if err != nil {
+		return nil, err
+	}
+	if pbState == nil {
+		return nil, errors.New("nil state")
+	}
+	return pbState, nil
+}
+
+func getBellatrixPbState(rawState interface{}) (*ethpb.BeaconStateBellatrix, error) {
+	pbState, err := statenative.ProtobufBeaconStateBellatrix(rawState)
+	if err != nil {
+		return nil, err
+	}
+	if pbState == nil {
+		return nil, errors.New("nil state")
+	}
+	return pbState, nil
+}
+
+func getCapellaPbState(rawState interface{}) (*ethpb.BeaconStateCapella, error) {
+	pbState, err := statenative.ProtobufBeaconStateCapella(rawState)
+	if err != nil {
+		return nil, err
+	}
+	if pbState == nil {
+		return nil, errors.New("nil state")
+	}
+	return pbState, nil
+}
+
+func getDenebPbState(rawState interface{}) (*ethpb.BeaconStateDeneb, error) {
+	pbState, err := statenative.ProtobufBeaconStateDeneb(rawState)
+	if err != nil {
+		return nil, err
+	}
+	if pbState == nil {
+		return nil, errors.New("nil state")
+	}
+	return pbState, nil
+}
+
 func (s *Store) storeValidatorEntriesSeparately(ctx context.Context, tx *bolt.Tx, validatorsEntries map[string]*ethpb.Validator) error {
 	valBkt := tx.Bucket(stateValidatorsBucket)
 	for hashStr, validatorEntry := range validatorsEntries {
@@ -472,6 +534,19 @@ func (s *Store) unmarshalState(_ context.Context, enc []byte, validatorEntries [
 	}

 	switch {
+	case hasDenebKey(enc):
+		protoState := &ethpb.BeaconStateDeneb{}
+		if err := protoState.UnmarshalSSZ(enc[len(denebKey):]); err != nil {
+			return nil, errors.Wrap(err, "failed to unmarshal encoding for Deneb")
+		}
+		ok, err := s.isStateValidatorMigrationOver()
+		if err != nil {
+			return nil, err
+		}
+		if ok {
+			protoState.Validators = validatorEntries
+		}
+		return statenative.InitializeFromProtoUnsafeDeneb(protoState)
 	case hasCapellaKey(enc):
 		// Marshal state bytes to capella beacon state.
 		protoState := &ethpb.BeaconStateCapella{}
@@ -579,6 +654,19 @@ func marshalState(ctx context.Context, st state.ReadOnlyBeaconState) ([]byte, er
 			return nil, err
 		}
 		return snappy.Encode(nil, append(capellaKey, rawObj...)), nil
+	case *ethpb.BeaconStateDeneb:
+		rState, ok := st.ToProtoUnsafe().(*ethpb.BeaconStateDeneb)
+		if !ok {
+			return nil, errors.New("non valid inner state")
+		}
+		if rState == nil {
+			return nil, errors.New("nil state")
+		}
+		rawObj, err := rState.MarshalSSZ()
+		if err != nil {
+			return nil, err
+		}
+		return snappy.Encode(nil, append(denebKey, rawObj...)), nil
 	default:
 		return nil, errors.New("invalid inner state")
 	}
--- a/beacon-chain/db/kv/state_test.go
+++ b/beacon-chain/db/kv/state_test.go
@@ -900,6 +900,100 @@ func TestBellatrixState_CanDelete(t *testing.T) {
 	require.Equal(t, state.ReadOnlyBeaconState(nil), savedS, "Unsaved state should've been nil")
 }

+func TestDenebState_CanSaveRetrieve(t *testing.T) {
+	db := setupDB(t)
+
+	r := [32]byte{'A'}
+
+	require.Equal(t, false, db.HasState(context.Background(), r))
+
+	st, _ := util.DeterministicGenesisStateDeneb(t, 1)
+	require.NoError(t, st.SetSlot(100))
+
+	require.NoError(t, db.SaveState(context.Background(), st, r))
+	require.Equal(t, true, db.HasState(context.Background(), r))
+
+	savedS, err := db.State(context.Background(), r)
+	require.NoError(t, err)
+
+	require.DeepSSZEqual(t, st.ToProtoUnsafe(), savedS.ToProtoUnsafe())
+
+	savedS, err = db.State(context.Background(), [32]byte{'B'})
+	require.NoError(t, err)
+	require.Equal(t, state.ReadOnlyBeaconState(nil), savedS, "Unsaved state should've been nil")
+}
+
+func TestDenebState_CanDelete(t *testing.T) {
+	db := setupDB(t)
+
+	r := [32]byte{'A'}
+
+	require.Equal(t, false, db.HasState(context.Background(), r))
+
+	st, _ := util.DeterministicGenesisStateDeneb(t, 1)
+	require.NoError(t, st.SetSlot(100))
+
+	require.NoError(t, db.SaveState(context.Background(), st, r))
+	require.Equal(t, true, db.HasState(context.Background(), r))
+
+	require.NoError(t, db.DeleteState(context.Background(), r))
+	savedS, err := db.State(context.Background(), r)
+	require.NoError(t, err)
+	require.Equal(t, state.ReadOnlyBeaconState(nil), savedS, "Unsaved state should've been nil")
+}
+
+func TestStateDeneb_CanSaveRetrieveValidatorEntries(t *testing.T) {
+	db := setupDB(t)
+
+	// enable historical state representation flag to test this
+	resetCfg := features.InitWithReset(&features.Flags{
+		EnableHistoricalSpaceRepresentation: true,
+	})
+	defer resetCfg()
+
+	r := [32]byte{'A'}
+
+	require.Equal(t, false, db.HasState(context.Background(), r))
+
+	stateValidators := validators(10)
+	st, _ := util.DeterministicGenesisStateDeneb(t, 20)
+	require.NoError(t, st.SetSlot(100))
+	require.NoError(t, st.SetValidators(stateValidators))
+
+	ctx := context.Background()
+	require.NoError(t, db.SaveState(ctx, st, r))
+	assert.Equal(t, true, db.HasState(context.Background(), r))
+
+	savedS, err := db.State(context.Background(), r)
+	require.NoError(t, err)
+
+	require.DeepSSZEqual(t, st.Validators(), savedS.Validators(), "saved state with validators and retrieved state are not matching")
+
+	// check if the index of the second state is still present.
+	err = db.db.Update(func(tx *bolt.Tx) error {
+		idxBkt := tx.Bucket(blockRootValidatorHashesBucket)
+		data := idxBkt.Get(r[:])
+		require.NotEqual(t, 0, len(data))
+		return nil
+	})
+	require.NoError(t, err)
+
+	// check if all the validator entries are still intact in the validator entry bucket.
+	err = db.db.Update(func(tx *bolt.Tx) error {
+		valBkt := tx.Bucket(stateValidatorsBucket)
+		// if any of the original validator entry is not present, then fail the test.
+		for _, val := range stateValidators {
+			hash, hashErr := val.HashTreeRoot()
+			assert.NoError(t, hashErr)
+			data := valBkt.Get(hash[:])
+			require.NotNil(t, data)
+			require.NotEqual(t, 0, len(data))
+		}
+		return nil
+	})
+	require.NoError(t, err)
+}
+
 func BenchmarkState_CheckStateSaveTime_1(b *testing.B)  { checkStateSaveTime(b, 1) }
 func BenchmarkState_CheckStateSaveTime_10(b *testing.B) { checkStateSaveTime(b, 10) }

--- a/beacon-chain/execution/BUILD.bazel
+++ b/beacon-chain/execution/BUILD.bazel
@@ -14,7 +14,6 @@ go_library(
        "metrics.go",
        "options.go",
        "prometheus.go",
-        "provider.go",
        "rpc_connection.go",
        "service.go",
    ],
@@ -49,7 +48,6 @@ go_library(
        "//crypto/hash:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//io/logs:go_default_library",
-        "//math:go_default_library",
        "//monitoring/clientstats:go_default_library",
        "//monitoring/tracing:go_default_library",
        "//network:go_default_library",
@@ -90,7 +88,6 @@ go_test(
        "init_test.go",
        "log_processing_test.go",
        "prometheus_test.go",
-        "provider_test.go",
        "service_test.go",
    ],
    data = glob(["testdata/**"]),
@@ -122,7 +119,6 @@ go_test(
        "//crypto/bls:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//monitoring/clientstats:go_default_library",
-        "//network/authorization:go_default_library",
        "//proto/engine/v1:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
        "//runtime/version:go_default_library",
--- a/beacon-chain/execution/engine_client.go
+++ b/beacon-chain/execution/engine_client.go
@@ -23,7 +23,6 @@ import (
 	payloadattribute "github.com/prysmaticlabs/prysm/v4/consensus-types/payload-attribute"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v4/math"
 	pb "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
@@ -50,6 +49,7 @@ const (
 	NewPayloadMethod = "engine_newPayloadV1"
 	// NewPayloadMethodV2 v2 request string for JSON-RPC.
 	NewPayloadMethodV2 = "engine_newPayloadV2"
+	NewPayloadMethodV3 = "engine_newPayloadV3"
 	// ForkchoiceUpdatedMethod v1 request string for JSON-RPC.
 	ForkchoiceUpdatedMethod = "engine_forkchoiceUpdatedV1"
 	// ForkchoiceUpdatedMethodV2 v2 request string for JSON-RPC.
@@ -58,6 +58,7 @@ const (
 	GetPayloadMethod = "engine_getPayloadV1"
 	// GetPayloadMethodV2 v2 request string for JSON-RPC.
 	GetPayloadMethodV2 = "engine_getPayloadV2"
+	GetPayloadMethodV3 = "engine_getPayloadV3"
 	// ExchangeTransitionConfigurationMethod v1 request string for JSON-RPC.
 	ExchangeTransitionConfigurationMethod = "engine_exchangeTransitionConfigurationV1"
 	// ExecutionBlockByHashMethod request string for JSON-RPC.
@@ -96,11 +97,11 @@ type ExecutionPayloadReconstructor interface {
 // EngineCaller defines a client that can interact with an Ethereum
 // execution node's engine service via JSON-RPC.
 type EngineCaller interface {
-	NewPayload(ctx context.Context, payload interfaces.ExecutionData) ([]byte, error)
+	NewPayload(ctx context.Context, payload interfaces.ExecutionData, versionedHashes [][32]byte) ([]byte, error)
 	ForkchoiceUpdated(
 		ctx context.Context, state *pb.ForkchoiceState, attrs payloadattribute.Attributer,
 	) (*pb.PayloadIDBytes, []byte, error)
-	GetPayload(ctx context.Context, payloadId [8]byte, slot primitives.Slot) (interfaces.ExecutionData, error)
+	GetPayload(ctx context.Context, payloadId [8]byte, slot primitives.Slot) (interfaces.ExecutionData, *pb.BlobsBundle, error)
 	ExchangeTransitionConfiguration(
 		ctx context.Context, cfg *pb.TransitionConfiguration,
 	) error
@@ -111,7 +112,7 @@ type EngineCaller interface {
 var EmptyBlockHash = errors.New("Block hash is empty 0x0000...")

 // NewPayload calls the engine_newPayloadVX method via JSON-RPC.
-func (s *Service) NewPayload(ctx context.Context, payload interfaces.ExecutionData) ([]byte, error) {
+func (s *Service) NewPayload(ctx context.Context, payload interfaces.ExecutionData, versionedHashes [][32]byte) ([]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.NewPayload")
 	defer span.End()
 	start := time.Now()
@@ -143,6 +144,15 @@ func (s *Service) NewPayload(ctx context.Context, payload interfaces.ExecutionDa
 		if err != nil {
 			return nil, handleRPCError(err)
 		}
+	case *pb.ExecutionPayloadDeneb:
+		payloadPb, ok := payload.Proto().(*pb.ExecutionPayloadDeneb)
+		if !ok {
+			return nil, errors.New("execution data must be a Deneb execution payload")
+		}
+		err := s.rpcClient.CallContext(ctx, result, NewPayloadMethodV3, payloadPb, versionedHashes)
+		if err != nil {
+			return nil, handleRPCError(err)
+		}
 	default:
 		return nil, errors.New("unknown execution data type")
 	}
@@ -190,7 +200,7 @@ func (s *Service) ForkchoiceUpdated(
 		if err != nil {
 			return nil, nil, handleRPCError(err)
 		}
-	case version.Capella:
+	case version.Capella, version.Deneb:
 		a, err := attrs.PbV2()
 		if err != nil {
 			return nil, nil, err
@@ -220,7 +230,8 @@ func (s *Service) ForkchoiceUpdated(
 }

 // GetPayload calls the engine_getPayloadVX method via JSON-RPC.
-func (s *Service) GetPayload(ctx context.Context, payloadId [8]byte, slot primitives.Slot) (interfaces.ExecutionData, error) {
+// It returns the execution data as well as the blobs bundle.
+func (s *Service) GetPayload(ctx context.Context, payloadId [8]byte, slot primitives.Slot) (interfaces.ExecutionData, *pb.BlobsBundle, error) {
 	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.GetPayload")
 	defer span.End()
 	start := time.Now()
@@ -232,23 +243,42 @@ func (s *Service) GetPayload(ctx context.Context, payloadId [8]byte, slot primit
 	ctx, cancel := context.WithDeadline(ctx, d)
 	defer cancel()

+	if slots.ToEpoch(slot) >= params.BeaconConfig().DenebForkEpoch {
+		result := &pb.ExecutionPayloadDenebWithValueAndBlobsBundle{}
+		err := s.rpcClient.CallContext(ctx, result, GetPayloadMethodV3, pb.PayloadIDBytes(payloadId))
+		if err != nil {
+			return nil, nil, handleRPCError(err)
+		}
+		ed, err := blocks.WrappedExecutionPayloadDeneb(result.Payload, blocks.PayloadValueToGwei(result.Value))
+		if err != nil {
+			return nil, nil, err
+		}
+		return ed, result.BlobsBundle, nil
+	}
+
 	if slots.ToEpoch(slot) >= params.BeaconConfig().CapellaForkEpoch {
 		result := &pb.ExecutionPayloadCapellaWithValue{}
 		err := s.rpcClient.CallContext(ctx, result, GetPayloadMethodV2, pb.PayloadIDBytes(payloadId))
 		if err != nil {
-			return nil, handleRPCError(err)
+			return nil, nil, handleRPCError(err)
 		}
-
-		v := big.NewInt(0).SetBytes(bytesutil.ReverseByteOrder(result.Value))
-		return blocks.WrappedExecutionPayloadCapella(result.Payload, math.WeiToGwei(v))
+		ed, err := blocks.WrappedExecutionPayloadCapella(result.Payload, blocks.PayloadValueToGwei(result.Value))
+		if err != nil {
+			return nil, nil, err
+		}
+		return ed, nil, nil
 	}

 	result := &pb.ExecutionPayload{}
 	err := s.rpcClient.CallContext(ctx, result, GetPayloadMethod, pb.PayloadIDBytes(payloadId))
 	if err != nil {
-		return nil, handleRPCError(err)
+		return nil, nil, handleRPCError(err)
 	}
-	return blocks.WrappedExecutionPayload(result)
+	ed, err := blocks.WrappedExecutionPayload(result)
+	if err != nil {
+		return nil, nil, err
+	}
+	return ed, nil, nil
 }

 // ExchangeTransitionConfiguration calls the engine_exchangeTransitionConfigurationV1 method via JSON-RPC.
@@ -684,7 +714,8 @@ func fullPayloadFromExecutionBlock(
 		txs[i] = txBin
 	}

-	if block.Version == version.Bellatrix {
+	switch block.Version {
+	case version.Bellatrix:
 		return blocks.WrappedExecutionPayload(&pb.ExecutionPayload{
 			ParentHash:    header.ParentHash(),
 			FeeRecipient:  header.FeeRecipient(),
@@ -701,24 +732,51 @@ func fullPayloadFromExecutionBlock(
 			BlockHash:     blockHash[:],
 			Transactions:  txs,
 		})
+	case version.Capella:
+		return blocks.WrappedExecutionPayloadCapella(&pb.ExecutionPayloadCapella{
+			ParentHash:    header.ParentHash(),
+			FeeRecipient:  header.FeeRecipient(),
+			StateRoot:     header.StateRoot(),
+			ReceiptsRoot:  header.ReceiptsRoot(),
+			LogsBloom:     header.LogsBloom(),
+			PrevRandao:    header.PrevRandao(),
+			BlockNumber:   header.BlockNumber(),
+			GasLimit:      header.GasLimit(),
+			GasUsed:       header.GasUsed(),
+			Timestamp:     header.Timestamp(),
+			ExtraData:     header.ExtraData(),
+			BaseFeePerGas: header.BaseFeePerGas(),
+			BlockHash:     blockHash[:],
+			Transactions:  txs,
+			Withdrawals:   block.Withdrawals,
+		}, 0) // We can't get the block value and don't care about the block value for this instance
+	case version.Deneb:
+		edg, err := header.ExcessDataGas()
+		if err != nil {
+			return nil, errors.Wrap(err, "unable to extract ExcessDataGas attribute from excution payload header")
+		}
+		return blocks.WrappedExecutionPayloadDeneb(
+			&pb.ExecutionPayloadDeneb{
+				ParentHash:    header.ParentHash(),
+				FeeRecipient:  header.FeeRecipient(),
+				StateRoot:     header.StateRoot(),
+				ReceiptsRoot:  header.ReceiptsRoot(),
+				LogsBloom:     header.LogsBloom(),
+				PrevRandao:    header.PrevRandao(),
+				BlockNumber:   header.BlockNumber(),
+				GasLimit:      header.GasLimit(),
+				GasUsed:       header.GasUsed(),
+				Timestamp:     header.Timestamp(),
+				ExtraData:     header.ExtraData(),
+				BaseFeePerGas: header.BaseFeePerGas(),
+				BlockHash:     blockHash[:],
+				Transactions:  txs,
+				Withdrawals:   block.Withdrawals,
+				ExcessDataGas: edg,
+			}, 0) // We can't get the block value and don't care about the block value for this instance
+	default:
+		return nil, fmt.Errorf("unknown execution block version %d", block.Version)
 	}
-	return blocks.WrappedExecutionPayloadCapella(&pb.ExecutionPayloadCapella{
-		ParentHash:    header.ParentHash(),
-		FeeRecipient:  header.FeeRecipient(),
-		StateRoot:     header.StateRoot(),
-		ReceiptsRoot:  header.ReceiptsRoot(),
-		LogsBloom:     header.LogsBloom(),
-		PrevRandao:    header.PrevRandao(),
-		BlockNumber:   header.BlockNumber(),
-		GasLimit:      header.GasLimit(),
-		GasUsed:       header.GasUsed(),
-		Timestamp:     header.Timestamp(),
-		ExtraData:     header.ExtraData(),
-		BaseFeePerGas: header.BaseFeePerGas(),
-		BlockHash:     blockHash[:],
-		Transactions:  txs,
-		Withdrawals:   block.Withdrawals,
-	}, 0) // We can't get the block value and don't care about the block value for this instance
 }

 // Handles errors received from the RPC server according to the specification.
--- a/beacon-chain/execution/engine_client_fuzz_test.go
+++ b/beacon-chain/execution/engine_client_fuzz_test.go
@@ -115,28 +115,32 @@ func FuzzExchangeTransitionConfiguration(f *testing.F) {

 func FuzzExecutionPayload(f *testing.F) {
 	logsBloom := [256]byte{'j', 'u', 'n', 'k'}
-	execData := &engine.ExecutableData{
-		ParentHash:    common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
-		FeeRecipient:  common.Address([20]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF}),
-		StateRoot:     common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
-		ReceiptsRoot:  common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
-		LogsBloom:     logsBloom[:],
-		Random:        common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
-		Number:        math.MaxUint64,
-		GasLimit:      math.MaxUint64,
-		GasUsed:       math.MaxUint64,
-		Timestamp:     100,
-		ExtraData:     nil,
-		BaseFeePerGas: big.NewInt(math.MaxInt),
-		BlockHash:     common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
-		Transactions:  [][]byte{{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}, {0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}, {0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}, {0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}},
+	execData := &engine.ExecutionPayloadEnvelope{
+		ExecutionPayload: &engine.ExecutableData{
+			ParentHash:    common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
+			FeeRecipient:  common.Address([20]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF}),
+			StateRoot:     common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
+			ReceiptsRoot:  common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
+			LogsBloom:     logsBloom[:],
+			Random:        common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
+			Number:        math.MaxUint64,
+			GasLimit:      math.MaxUint64,
+			GasUsed:       math.MaxUint64,
+			Timestamp:     100,
+			ExtraData:     nil,
+			BaseFeePerGas: big.NewInt(math.MaxInt),
+			BlockHash:     common.Hash([32]byte{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}),
+			Transactions:  [][]byte{{0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}, {0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}, {0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}, {0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01, 0xFF, 0x01}},
+			Withdrawals:   []*types.Withdrawal{},
+		},
+		BlockValue: nil,
 	}
 	output, err := json.Marshal(execData)
 	assert.NoError(f, err)
 	f.Add(output)
 	f.Fuzz(func(t *testing.T, jsonBlob []byte) {
-		gethResp := &engine.ExecutableData{}
-		prysmResp := &pb.ExecutionPayload{}
+		gethResp := &engine.ExecutionPayloadEnvelope{}
+		prysmResp := &pb.ExecutionPayloadCapellaWithValue{}
 		gethErr := json.Unmarshal(jsonBlob, gethResp)
 		prysmErr := json.Unmarshal(jsonBlob, prysmResp)
 		assert.Equal(t, gethErr != nil, prysmErr != nil, fmt.Sprintf("geth and prysm unmarshaller return inconsistent errors. %v and %v", gethErr, prysmErr))
@@ -147,10 +151,10 @@ func FuzzExecutionPayload(f *testing.F) {
 		gethBlob, gethErr := json.Marshal(gethResp)
 		prysmBlob, prysmErr := json.Marshal(prysmResp)
 		assert.Equal(t, gethErr != nil, prysmErr != nil, "geth and prysm unmarshaller return inconsistent errors")
-		newGethResp := &engine.ExecutableData{}
+		newGethResp := &engine.ExecutionPayloadEnvelope{}
 		newGethErr := json.Unmarshal(prysmBlob, newGethResp)
 		assert.NoError(t, newGethErr)
-		newGethResp2 := &engine.ExecutableData{}
+		newGethResp2 := &engine.ExecutionPayloadEnvelope{}
 		newGethErr = json.Unmarshal(gethBlob, newGethResp2)
 		assert.NoError(t, newGethErr)

--- a/beacon-chain/execution/engine_client_test.go
+++ b/beacon-chain/execution/engine_client_test.go
@@ -75,7 +75,7 @@ func TestClient_IPC(t *testing.T) {
 		want, ok := fix["ExecutionPayload"].(*pb.ExecutionPayload)
 		require.Equal(t, true, ok)
 		payloadId := [8]byte{1}
-		resp, err := srv.GetPayload(ctx, payloadId, 1)
+		resp, _, err := srv.GetPayload(ctx, payloadId, 1)
 		require.NoError(t, err)
 		resPb, err := resp.PbBellatrix()
 		require.NoError(t, err)
@@ -85,7 +85,7 @@ func TestClient_IPC(t *testing.T) {
 		want, ok := fix["ExecutionPayloadCapellaWithValue"].(*pb.ExecutionPayloadCapellaWithValue)
 		require.Equal(t, true, ok)
 		payloadId := [8]byte{1}
-		resp, err := srv.GetPayload(ctx, payloadId, params.BeaconConfig().SlotsPerEpoch)
+		resp, _, err := srv.GetPayload(ctx, payloadId, params.BeaconConfig().SlotsPerEpoch)
 		require.NoError(t, err)
 		resPb, err := resp.PbCapella()
 		require.NoError(t, err)
@@ -118,7 +118,7 @@ func TestClient_IPC(t *testing.T) {
 		require.Equal(t, true, ok)
 		wrappedPayload, err := blocks.WrappedExecutionPayload(req)
 		require.NoError(t, err)
-		latestValidHash, err := srv.NewPayload(ctx, wrappedPayload)
+		latestValidHash, err := srv.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.NoError(t, err)
 		require.DeepEqual(t, bytesutil.ToBytes32(want.LatestValidHash), bytesutil.ToBytes32(latestValidHash))
 	})
@@ -129,7 +129,7 @@ func TestClient_IPC(t *testing.T) {
 		require.Equal(t, true, ok)
 		wrappedPayload, err := blocks.WrappedExecutionPayloadCapella(req, 0)
 		require.NoError(t, err)
-		latestValidHash, err := srv.NewPayload(ctx, wrappedPayload)
+		latestValidHash, err := srv.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.NoError(t, err)
 		require.DeepEqual(t, bytesutil.ToBytes32(want.LatestValidHash), bytesutil.ToBytes32(latestValidHash))
 	})
@@ -163,6 +163,7 @@ func TestClient_HTTP(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	cfg := params.BeaconConfig().Copy()
 	cfg.CapellaForkEpoch = 1
+	cfg.DenebForkEpoch = 2
 	params.OverrideBeaconConfig(cfg)

 	t.Run(GetPayloadMethod, func(t *testing.T) {
@@ -203,7 +204,7 @@ func TestClient_HTTP(t *testing.T) {
 		client.rpcClient = rpcClient

 		// We call the RPC method via HTTP and expect a proper result.
-		resp, err := client.GetPayload(ctx, payloadId, 1)
+		resp, _, err := client.GetPayload(ctx, payloadId, 1)
 		require.NoError(t, err)
 		pb, err := resp.PbBellatrix()
 		require.NoError(t, err)
@@ -247,7 +248,7 @@ func TestClient_HTTP(t *testing.T) {
 		client.rpcClient = rpcClient

 		// We call the RPC method via HTTP and expect a proper result.
-		resp, err := client.GetPayload(ctx, payloadId, params.BeaconConfig().SlotsPerEpoch)
+		resp, _, err := client.GetPayload(ctx, payloadId, params.BeaconConfig().SlotsPerEpoch)
 		require.NoError(t, err)
 		pb, err := resp.PbCapella()
 		require.NoError(t, err)
@@ -262,6 +263,60 @@ func TestClient_HTTP(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, uint64(1236), v)
 	})
+	t.Run(GetPayloadMethodV3, func(t *testing.T) {
+		payloadId := [8]byte{1}
+		want, ok := fix["ExecutionPayloadDenebWithValue"].(*pb.GetPayloadV3ResponseJson)
+		require.Equal(t, true, ok)
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			defer func() {
+				require.NoError(t, r.Body.Close())
+			}()
+			enc, err := io.ReadAll(r.Body)
+			require.NoError(t, err)
+			jsonRequestString := string(enc)
+
+			reqArg, err := json.Marshal(pb.PayloadIDBytes(payloadId))
+			require.NoError(t, err)
+
+			// We expect the JSON string RPC request contains the right arguments.
+			require.Equal(t, true, strings.Contains(
+				jsonRequestString, string(reqArg),
+			))
+			resp := map[string]interface{}{
+				"jsonrpc": "2.0",
+				"id":      1,
+				"result":  want,
+			}
+			err = json.NewEncoder(w).Encode(resp)
+			require.NoError(t, err)
+		}))
+		defer srv.Close()
+
+		rpcClient, err := rpc.DialHTTP(srv.URL)
+		require.NoError(t, err)
+		defer rpcClient.Close()
+
+		client := &Service{}
+		client.rpcClient = rpcClient
+
+		// We call the RPC method via HTTP and expect a proper result.
+		resp, blobsBundle, err := client.GetPayload(ctx, payloadId, 2*params.BeaconConfig().SlotsPerEpoch)
+		require.NoError(t, err)
+		g, err := resp.ExcessDataGas()
+		require.NoError(t, err)
+		require.DeepEqual(t, uint64(3), g)
+		g, err = resp.DataGasUsed()
+		require.NoError(t, err)
+		require.DeepEqual(t, uint64(2), g)
+
+		commitments := [][]byte{bytesutil.PadTo([]byte("commitment1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("commitment2"), fieldparams.BLSPubkeyLength)}
+		require.DeepEqual(t, commitments, blobsBundle.KzgCommitments)
+		proofs := [][]byte{bytesutil.PadTo([]byte("proof1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("proof2"), fieldparams.BLSPubkeyLength)}
+		require.DeepEqual(t, proofs, blobsBundle.Proofs)
+		blobs := [][]byte{bytesutil.PadTo([]byte("a"), fieldparams.BlobLength), bytesutil.PadTo([]byte("b"), fieldparams.BlobLength)}
+		require.DeepEqual(t, blobs, blobsBundle.Blobs)
+	})
 	t.Run(ForkchoiceUpdatedMethod+" VALID status", func(t *testing.T) {
 		forkChoiceState := &pb.ForkchoiceState{
 			HeadBlockHash:      []byte("head"),
@@ -412,7 +467,7 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayload(execPayload)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.NoError(t, err)
 		require.DeepEqual(t, want.LatestValidHash, resp)
 	})
@@ -426,7 +481,21 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayloadCapella(execPayload, 0)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
+		require.NoError(t, err)
+		require.DeepEqual(t, want.LatestValidHash, resp)
+	})
+	t.Run(NewPayloadMethodV3+" VALID status", func(t *testing.T) {
+		execPayload, ok := fix["ExecutionPayloadDeneb"].(*pb.ExecutionPayloadDeneb)
+		require.Equal(t, true, ok)
+		want, ok := fix["ValidPayloadStatus"].(*pb.PayloadStatus)
+		require.Equal(t, true, ok)
+		client := newPayloadV3Setup(t, want, execPayload)
+
+		// We call the RPC method via HTTP and expect a proper result.
+		wrappedPayload, err := blocks.WrappedExecutionPayloadDeneb(execPayload, 0)
+		require.NoError(t, err)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.NoError(t, err)
 		require.DeepEqual(t, want.LatestValidHash, resp)
 	})
@@ -440,7 +509,7 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayload(execPayload)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrAcceptedSyncingPayloadStatus, err)
 		require.DeepEqual(t, []uint8(nil), resp)
 	})
@@ -454,7 +523,21 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayloadCapella(execPayload, 0)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
+		require.ErrorIs(t, ErrAcceptedSyncingPayloadStatus, err)
+		require.DeepEqual(t, []uint8(nil), resp)
+	})
+	t.Run(NewPayloadMethodV3+" SYNCING status", func(t *testing.T) {
+		execPayload, ok := fix["ExecutionPayloadDeneb"].(*pb.ExecutionPayloadDeneb)
+		require.Equal(t, true, ok)
+		want, ok := fix["SyncingStatus"].(*pb.PayloadStatus)
+		require.Equal(t, true, ok)
+		client := newPayloadV3Setup(t, want, execPayload)
+
+		// We call the RPC method via HTTP and expect a proper result.
+		wrappedPayload, err := blocks.WrappedExecutionPayloadDeneb(execPayload, 0)
+		require.NoError(t, err)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrAcceptedSyncingPayloadStatus, err)
 		require.DeepEqual(t, []uint8(nil), resp)
 	})
@@ -468,7 +551,7 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayload(execPayload)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrInvalidBlockHashPayloadStatus, err)
 		require.DeepEqual(t, []uint8(nil), resp)
 	})
@@ -482,7 +565,21 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayloadCapella(execPayload, 0)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
+		require.ErrorIs(t, ErrInvalidBlockHashPayloadStatus, err)
+		require.DeepEqual(t, []uint8(nil), resp)
+	})
+	t.Run(NewPayloadMethodV3+" INVALID_BLOCK_HASH status", func(t *testing.T) {
+		execPayload, ok := fix["ExecutionPayloadDeneb"].(*pb.ExecutionPayloadDeneb)
+		require.Equal(t, true, ok)
+		want, ok := fix["InvalidBlockHashStatus"].(*pb.PayloadStatus)
+		require.Equal(t, true, ok)
+		client := newPayloadV3Setup(t, want, execPayload)
+
+		// We call the RPC method via HTTP and expect a proper result.
+		wrappedPayload, err := blocks.WrappedExecutionPayloadDeneb(execPayload, 0)
+		require.NoError(t, err)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrInvalidBlockHashPayloadStatus, err)
 		require.DeepEqual(t, []uint8(nil), resp)
 	})
@@ -496,7 +593,7 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayload(execPayload)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrInvalidPayloadStatus, err)
 		require.DeepEqual(t, want.LatestValidHash, resp)
 	})
@@ -510,7 +607,21 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayloadCapella(execPayload, 0)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
+		require.ErrorIs(t, ErrInvalidPayloadStatus, err)
+		require.DeepEqual(t, want.LatestValidHash, resp)
+	})
+	t.Run(NewPayloadMethodV3+" INVALID status", func(t *testing.T) {
+		execPayload, ok := fix["ExecutionPayloadDeneb"].(*pb.ExecutionPayloadDeneb)
+		require.Equal(t, true, ok)
+		want, ok := fix["InvalidStatus"].(*pb.PayloadStatus)
+		require.Equal(t, true, ok)
+		client := newPayloadV3Setup(t, want, execPayload)
+
+		// We call the RPC method via HTTP and expect a proper result.
+		wrappedPayload, err := blocks.WrappedExecutionPayloadDeneb(execPayload, 0)
+		require.NoError(t, err)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrInvalidPayloadStatus, err)
 		require.DeepEqual(t, want.LatestValidHash, resp)
 	})
@@ -524,7 +635,7 @@ func TestClient_HTTP(t *testing.T) {
 		// We call the RPC method via HTTP and expect a proper result.
 		wrappedPayload, err := blocks.WrappedExecutionPayload(execPayload)
 		require.NoError(t, err)
-		resp, err := client.NewPayload(ctx, wrappedPayload)
+		resp, err := client.NewPayload(ctx, wrappedPayload, [][32]byte{})
 		require.ErrorIs(t, ErrUnknownPayloadStatus, err)
 		require.DeepEqual(t, []uint8(nil), resp)
 	})
@@ -1306,6 +1417,25 @@ func fixtures() map[string]interface{} {
 		Transactions:  [][]byte{foo[:]},
 		Withdrawals:   []*pb.Withdrawal{},
 	}
+	executionPayloadFixtureDeneb := &pb.ExecutionPayloadDeneb{
+		ParentHash:    foo[:],
+		FeeRecipient:  bar,
+		StateRoot:     foo[:],
+		ReceiptsRoot:  foo[:],
+		LogsBloom:     baz,
+		PrevRandao:    foo[:],
+		BlockNumber:   1,
+		GasLimit:      1,
+		GasUsed:       1,
+		Timestamp:     1,
+		ExtraData:     foo[:],
+		BaseFeePerGas: bytesutil.PadTo(baseFeePerGas.Bytes(), fieldparams.RootLength),
+		BlockHash:     foo[:],
+		Transactions:  [][]byte{foo[:]},
+		Withdrawals:   []*pb.Withdrawal{},
+		DataGasUsed:   2,
+		ExcessDataGas: 3,
+	}
 	hexUint := hexutil.Uint64(1)
 	executionPayloadWithValueFixtureCapella := &pb.GetPayloadV2ResponseJson{
 		ExecutionPayload: &pb.ExecutionPayloadCapellaJSON{
@@ -1326,6 +1456,34 @@ func fixtures() map[string]interface{} {
 		},
 		BlockValue: "0x11fffffffff",
 	}
+	dgu := hexutil.Uint64(2)
+	edg := hexutil.Uint64(3)
+	executionPayloadWithValueFixtureDeneb := &pb.GetPayloadV3ResponseJson{
+		ExecutionPayload: &pb.ExecutionPayloadDenebJSON{
+			ParentHash:    &common.Hash{'a'},
+			FeeRecipient:  &common.Address{'b'},
+			StateRoot:     &common.Hash{'c'},
+			ReceiptsRoot:  &common.Hash{'d'},
+			LogsBloom:     &hexutil.Bytes{'e'},
+			PrevRandao:    &common.Hash{'f'},
+			BaseFeePerGas: "0x123",
+			BlockHash:     &common.Hash{'g'},
+			Transactions:  []hexutil.Bytes{{'h'}},
+			Withdrawals:   []*pb.Withdrawal{},
+			BlockNumber:   &hexUint,
+			GasLimit:      &hexUint,
+			GasUsed:       &hexUint,
+			Timestamp:     &hexUint,
+			DataGasUsed:   &dgu,
+			ExcessDataGas: &edg,
+		},
+		BlockValue: "0x11fffffffff",
+		BlobsBundle: &pb.BlobBundleJSON{
+			Commitments: [][48]byte{bytesutil.ToBytes48([]byte("commitment1")), bytesutil.ToBytes48([]byte("commitment2"))},
+			Proofs:      [][48]byte{bytesutil.ToBytes48([]byte("proof1")), bytesutil.ToBytes48([]byte("proof2"))},
+			Blobs:       [][]byte{{'a'}, {'b'}},
+		},
+	}
 	parent := bytesutil.PadTo([]byte("parentHash"), fieldparams.RootLength)
 	sha3Uncles := bytesutil.PadTo([]byte("sha3Uncles"), fieldparams.RootLength)
 	miner := bytesutil.PadTo([]byte("miner"), fieldparams.FeeRecipientLength)
@@ -1421,7 +1579,9 @@ func fixtures() map[string]interface{} {
 		"ExecutionBlock":                    executionBlock,
 		"ExecutionPayload":                  executionPayloadFixture,
 		"ExecutionPayloadCapella":           executionPayloadFixtureCapella,
+		"ExecutionPayloadDeneb":             executionPayloadFixtureDeneb,
 		"ExecutionPayloadCapellaWithValue":  executionPayloadWithValueFixtureCapella,
+		"ExecutionPayloadDenebWithValue":    executionPayloadWithValueFixtureDeneb,
 		"ValidPayloadStatus":                validStatus,
 		"InvalidBlockHashStatus":            inValidBlockHashStatus,
 		"AcceptedStatus":                    acceptedStatus,
@@ -1496,6 +1656,126 @@ func Test_fullPayloadFromExecutionBlock(t *testing.T) {
 	}
 }

+func Test_fullPayloadFromExecutionBlockCapella(t *testing.T) {
+	type args struct {
+		header *pb.ExecutionPayloadHeaderCapella
+		block  *pb.ExecutionBlock
+	}
+	wantedHash := common.BytesToHash([]byte("foo"))
+	tests := []struct {
+		name string
+		args args
+		want func() interfaces.ExecutionData
+		err  string
+	}{
+		{
+			name: "block hash field in header and block hash mismatch",
+			args: args{
+				header: &pb.ExecutionPayloadHeaderCapella{
+					BlockHash: []byte("foo"),
+				},
+				block: &pb.ExecutionBlock{
+					Version: version.Capella,
+					Hash:    common.BytesToHash([]byte("bar")),
+				},
+			},
+			err: "does not match execution block hash",
+		},
+		{
+			name: "ok",
+			args: args{
+				header: &pb.ExecutionPayloadHeaderCapella{
+					BlockHash: wantedHash[:],
+				},
+				block: &pb.ExecutionBlock{
+					Version: version.Capella,
+					Hash:    wantedHash,
+				},
+			},
+			want: func() interfaces.ExecutionData {
+				p, err := blocks.WrappedExecutionPayloadCapella(&pb.ExecutionPayloadCapella{
+					BlockHash:    wantedHash[:],
+					Transactions: [][]byte{},
+				}, 0)
+				require.NoError(t, err)
+				return p
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			wrapped, err := blocks.WrappedExecutionPayloadHeaderCapella(tt.args.header, 0)
+			require.NoError(t, err)
+			got, err := fullPayloadFromExecutionBlock(wrapped, tt.args.block)
+			if err != nil {
+				assert.ErrorContains(t, tt.err, err)
+			} else {
+				assert.DeepEqual(t, tt.want(), got)
+			}
+		})
+	}
+}
+
+func Test_fullPayloadFromExecutionBlockDeneb(t *testing.T) {
+	type args struct {
+		header *pb.ExecutionPayloadHeaderDeneb
+		block  *pb.ExecutionBlock
+	}
+	wantedHash := common.BytesToHash([]byte("foo"))
+	tests := []struct {
+		name string
+		args args
+		want func() interfaces.ExecutionData
+		err  string
+	}{
+		{
+			name: "block hash field in header and block hash mismatch",
+			args: args{
+				header: &pb.ExecutionPayloadHeaderDeneb{
+					BlockHash: []byte("foo"),
+				},
+				block: &pb.ExecutionBlock{
+					Version: version.Deneb,
+					Hash:    common.BytesToHash([]byte("bar")),
+				},
+			},
+			err: "does not match execution block hash",
+		},
+		{
+			name: "ok",
+			args: args{
+				header: &pb.ExecutionPayloadHeaderDeneb{
+					BlockHash: wantedHash[:],
+				},
+				block: &pb.ExecutionBlock{
+					Version: version.Deneb,
+					Hash:    wantedHash,
+				},
+			},
+			want: func() interfaces.ExecutionData {
+				p, err := blocks.WrappedExecutionPayloadDeneb(&pb.ExecutionPayloadDeneb{
+					BlockHash:    wantedHash[:],
+					Transactions: [][]byte{},
+				}, 0)
+				require.NoError(t, err)
+				return p
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			wrapped, err := blocks.WrappedExecutionPayloadHeaderDeneb(tt.args.header, 0)
+			require.NoError(t, err)
+			got, err := fullPayloadFromExecutionBlock(wrapped, tt.args.block)
+			if err != nil {
+				assert.ErrorContains(t, tt.err, err)
+			} else {
+				assert.DeepEqual(t, tt.want(), got)
+			}
+		})
+	}
+}
+
 func TestHeaderByHash_NotFound(t *testing.T) {
 	srv := &Service{}
 	srv.rpcClient = RPCClientBad{}
@@ -1819,6 +2099,40 @@ func newPayloadV2Setup(t *testing.T, status *pb.PayloadStatus, payload *pb.Execu
 	return service
 }

+func newPayloadV3Setup(t *testing.T, status *pb.PayloadStatus, payload *pb.ExecutionPayloadDeneb) *Service {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		defer func() {
+			require.NoError(t, r.Body.Close())
+		}()
+		enc, err := io.ReadAll(r.Body)
+		require.NoError(t, err)
+		jsonRequestString := string(enc)
+
+		reqArg, err := json.Marshal(payload)
+		require.NoError(t, err)
+
+		// We expect the JSON string RPC request contains the right arguments.
+		require.Equal(t, true, strings.Contains(
+			jsonRequestString, string(reqArg),
+		))
+		resp := map[string]interface{}{
+			"jsonrpc": "2.0",
+			"id":      1,
+			"result":  status,
+		}
+		err = json.NewEncoder(w).Encode(resp)
+		require.NoError(t, err)
+	}))
+
+	rpcClient, err := rpc.DialHTTP(srv.URL)
+	require.NoError(t, err)
+
+	service := &Service{}
+	service.rpcClient = rpcClient
+	return service
+}
+
 func TestCapella_PayloadBodiesByHash(t *testing.T) {
 	resetFn := features.InitWithReset(&features.Flags{
 		EnableOptionalEngineMethods: true,
--- a/beacon-chain/execution/options.go
+++ b/beacon-chain/execution/options.go
@@ -7,6 +7,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/v4/network"
 	"github.com/prysmaticlabs/prysm/v4/network/authorization"
 )

@@ -15,7 +16,7 @@ type Option func(s *Service) error
 // WithHttpEndpoint parse http endpoint for the powchain service to use.
 func WithHttpEndpoint(endpointString string) Option {
 	return func(s *Service) error {
-		s.cfg.currHttpEndpoint = HttpEndpoint(endpointString)
+		s.cfg.currHttpEndpoint = network.HttpEndpoint(endpointString)
 		return nil
 	}
 }
@@ -27,7 +28,7 @@ func WithHttpEndpointAndJWTSecret(endpointString string, secret []byte) Option {
 			return nil
 		}
 		// Overwrite authorization type for all endpoints to be of a bearer type.
-		hEndpoint := HttpEndpoint(endpointString)
+		hEndpoint := network.HttpEndpoint(endpointString)
 		hEndpoint.Auth.Method = authorization.Bearer
 		hEndpoint.Auth.Value = string(secret)

--- a/beacon-chain/execution/prometheus_test.go
+++ b/beacon-chain/execution/prometheus_test.go
@@ -15,7 +15,7 @@ import (
 func TestCleanup(t *testing.T) {
 	ctx := context.Background()
 	pc, err := NewPowchainCollector(ctx)
-	assert.NoError(t, err, "Uxpected error caling NewPowchainCollector")
+	assert.NoError(t, err, "Unexpected error calling NewPowchainCollector")
 	unregistered := pc.unregister()
 	assert.Equal(t, true, unregistered, "PowchainCollector.unregister did not return true (via prometheus.DefaultRegistry)")
 	// PowchainCollector is a prometheus.Collector, so we should be able to register it again
@@ -39,7 +39,7 @@ func TestCleanup(t *testing.T) {
 func TestCancelation(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	pc, err := NewPowchainCollector(ctx)
-	assert.NoError(t, err, "Uxpected error caling NewPowchainCollector")
+	assert.NoError(t, err, "Unexpected error calling NewPowchainCollector")
 	ticker := time.NewTicker(10 * time.Second)
 	cancel()
 	select {
--- a/beacon-chain/execution/provider.go
+++ b/beacon-chain/execution/provider.go
@@ -1,49 +0,0 @@
-package execution
-
-import (
-	"encoding/base64"
-	"strings"
-
-	"github.com/prysmaticlabs/prysm/v4/network"
-	"github.com/prysmaticlabs/prysm/v4/network/authorization"
-)
-
-// HttpEndpoint extracts an httputils.Endpoint from the provider parameter.
-func HttpEndpoint(eth1Provider string) network.Endpoint {
-	endpoint := network.Endpoint{
-		Url: "",
-		Auth: network.AuthorizationData{
-			Method: authorization.None,
-			Value:  "",
-		}}
-
-	authValues := strings.Split(eth1Provider, ",")
-	endpoint.Url = strings.TrimSpace(authValues[0])
-	if len(authValues) > 2 {
-		log.Errorf(
-			"ETH1 endpoint string can contain one comma for specifying the authorization header to access the provider."+
-				" String contains too many commas: %d. Skipping authorization.", len(authValues)-1)
-	} else if len(authValues) == 2 {
-		switch network.Method(strings.TrimSpace(authValues[1])) {
-		case authorization.Basic:
-			basicAuthValues := strings.Split(strings.TrimSpace(authValues[1]), " ")
-			if len(basicAuthValues) != 2 {
-				log.Errorf("Basic Authentication has incorrect format. Skipping authorization.")
-			} else {
-				endpoint.Auth.Method = authorization.Basic
-				endpoint.Auth.Value = base64.StdEncoding.EncodeToString([]byte(basicAuthValues[1]))
-			}
-		case authorization.Bearer:
-			bearerAuthValues := strings.Split(strings.TrimSpace(authValues[1]), " ")
-			if len(bearerAuthValues) != 2 {
-				log.Errorf("Bearer Authentication has incorrect format. Skipping authorization.")
-			} else {
-				endpoint.Auth.Method = authorization.Bearer
-				endpoint.Auth.Value = bearerAuthValues[1]
-			}
-		case authorization.None:
-			log.Errorf("Authorization has incorrect format or authorization type is not supported.")
-		}
-	}
-	return endpoint
-}
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .1.0
 .2.1