update to latest version of our fastssz fork (#14519)

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>

CHANGELOG.md

@@ -13,12 +13,20 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Light client support: Implement `ComputeFieldRootsForBlockBody`.
 - Light client support: Add light client database changes.
 - Light client support: Implement capella and deneb changes.
-- Light client support: Implement `BlockToLightClientHeaderXXX` functions upto Deneb
+- Light client support: Implement `BlockToLightClientHeader` function.
+- Light client support: Consensus types.
 - GetBeaconStateV2: add Electra case.
 - Implement [consensus-specs/3875](https://github.com/ethereum/consensus-specs/pull/3875)
+- Tests to ensure sepolia config matches the official upstream yaml
+- HTTP endpoint for PublishBlobs
+- GetBlockV2, GetBlindedBlock, ProduceBlockV2, ProduceBlockV3: add Electra case.
+- Add Electra support and tests for light client functions
+- fastssz version bump (better error messages).
+- SSE implementation that sheds stuck clients. [pr](https://github.com/prysmaticlabs/prysm/pull/14413)
 
 ### Changed
 
+- Electra: Updated interop genesis generator to support Electra.
 - `getLocalPayload` has been refactored to enable work in ePBS branch.
 - `TestNodeServer_GetPeer` and `TestNodeServer_ListPeers` test flakes resolved by iterating the whole peer list to find
   a match rather than taking the first peer in the map.
@@ -39,7 +47,11 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Updated k8s-io/client-go to v0.30.4 and k8s-io/apimachinery to v0.30.4
 - Migrated tracing library from opencensus to opentelemetry for both the beacon node and validator.
 - Refactored light client code to make it more readable and make future PRs easier.
+- Update light client helper functions to reference `dev` branch of CL specs
 - Updated Libp2p Dependencies to allow prysm to use gossipsub v1.2 .
+- Updated Sepolia bootnodes.
+- Make committee aware packing the default by deprecating `--enable-committee-aware-packing`.
+- Moved `ConvertKzgCommitmentToVersionedHash` to the `primitives` package.
 
 ### Deprecated
 - `--disable-grpc-gateway` flag is deprecated due to grpc gateway removal.
@@ -64,7 +76,10 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Core: Fixed slash processing causing extra hashing.
 - Core: Fixed extra allocations when processing slashings.
 - remove unneeded container in blob sidecar ssz response
+- Light client support: create finalized header based on finalizedBlock's version, not attestedBlock.
+- Light client support: fix light client attested header execution fields' wrong version bug.
 - Testing: added custom matcher for better push settings testing.
+- Registered `GetDepositSnapshot` Beacon API endpoint.
 
 ### Security
 

WORKSPACE

@@ -342,6 +342,22 @@ filegroup(
     url = "https://github.com/eth-clients/holesky/archive/874c199423ccd180607320c38cbaca05d9a1573a.tar.gz",  # 2024-06-18
 )
 
+http_archive(
+    name = "sepolia_testnet",
+    build_file_content = """
+filegroup(
+    name = "configs",
+    srcs = [
+        "metadata/config.yaml",
+    ],
+    visibility = ["//visibility:public"],
+)
+""",
+    integrity = "sha256-cY/UgpCcYEhQf7JefD65FI8tn/A+rAvKhcm2/qiVdqY=",
+    strip_prefix = "sepolia-f2c219a93c4491cee3d90c18f2f8e82aed850eab",
+    url = "https://github.com/eth-clients/sepolia/archive/f2c219a93c4491cee3d90c18f2f8e82aed850eab.tar.gz",  # 2024-09-19
+)
+
 http_archive(
     name = "com_google_protobuf",
     sha256 = "9bd87b8280ef720d3240514f884e56a712f2218f0d693b48050c836028940a42",

api/headers.go

@@ -1,5 +1,7 @@
 package api
 
+import "net/http"
+
 const (
 	VersionHeader                 = "Eth-Consensus-Version"
 	ExecutionPayloadBlindedHeader = "Eth-Execution-Payload-Blinded"
@@ -10,3 +12,9 @@ const (
 	EventStreamMediaType          = "text/event-stream"
 	KeepAlive                     = "keep-alive"
 )
+
+// SetSSEHeaders sets the headers needed for a server-sent event response.
+func SetSSEHeaders(w http.ResponseWriter) {
+	w.Header().Set("Content-Type", EventStreamMediaType)
+	w.Header().Set("Connection", KeepAlive)
+}

api/server/structs/BUILD.bazel

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "block.go",
         "conversions.go",
+        "conversions_blob.go",
         "conversions_block.go",
         "conversions_lightclient.go",
         "conversions_state.go",

api/server/structs/conversions.go

@@ -15,6 +15,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/math"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	ethv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 )
 
@@ -1508,3 +1509,37 @@ func PendingConsolidationsFromConsensus(cs []*eth.PendingConsolidation) []*Pendi
 	}
 	return consolidations
 }
+
+func HeadEventFromV1(event *ethv1.EventHead) *HeadEvent {
+	return &HeadEvent{
+		Slot:                      fmt.Sprintf("%d", event.Slot),
+		Block:                     hexutil.Encode(event.Block),
+		State:                     hexutil.Encode(event.State),
+		EpochTransition:           event.EpochTransition,
+		ExecutionOptimistic:       event.ExecutionOptimistic,
+		PreviousDutyDependentRoot: hexutil.Encode(event.PreviousDutyDependentRoot),
+		CurrentDutyDependentRoot:  hexutil.Encode(event.CurrentDutyDependentRoot),
+	}
+}
+
+func FinalizedCheckpointEventFromV1(event *ethv1.EventFinalizedCheckpoint) *FinalizedCheckpointEvent {
+	return &FinalizedCheckpointEvent{
+		Block:               hexutil.Encode(event.Block),
+		State:               hexutil.Encode(event.State),
+		Epoch:               fmt.Sprintf("%d", event.Epoch),
+		ExecutionOptimistic: event.ExecutionOptimistic,
+	}
+}
+
+func EventChainReorgFromV1(event *ethv1.EventChainReorg) *ChainReorgEvent {
+	return &ChainReorgEvent{
+		Slot:                fmt.Sprintf("%d", event.Slot),
+		Depth:               fmt.Sprintf("%d", event.Depth),
+		OldHeadBlock:        hexutil.Encode(event.OldHeadBlock),
+		NewHeadBlock:        hexutil.Encode(event.NewHeadBlock),
+		OldHeadState:        hexutil.Encode(event.OldHeadState),
+		NewHeadState:        hexutil.Encode(event.NewHeadState),
+		Epoch:               fmt.Sprintf("%d", event.Epoch),
+		ExecutionOptimistic: event.ExecutionOptimistic,
+	}
+}

api/server/structs/conversions_blob.go

@@ -0,0 +1,61 @@
+package structs
+
+import (
+	"strconv"
+
+	"github.com/prysmaticlabs/prysm/v5/api/server"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+func (sc *Sidecar) ToConsensus() (*eth.BlobSidecar, error) {
+	if sc == nil {
+		return nil, errNilValue
+	}
+
+	index, err := strconv.ParseUint(sc.Index, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Index")
+	}
+
+	blob, err := bytesutil.DecodeHexWithLength(sc.Blob, 131072)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Blob")
+	}
+
+	kzgCommitment, err := bytesutil.DecodeHexWithLength(sc.KzgCommitment, 48)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "KzgCommitment")
+	}
+
+	kzgProof, err := bytesutil.DecodeHexWithLength(sc.KzgProof, 48)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "KzgProof")
+	}
+
+	header, err := sc.SignedBeaconBlockHeader.ToConsensus()
+	if err != nil {
+		return nil, server.NewDecodeError(err, "SignedBeaconBlockHeader")
+	}
+
+	// decode the commitment inclusion proof
+	var commitmentInclusionProof [][]byte
+	for _, proof := range sc.CommitmentInclusionProof {
+		proofBytes, err := bytesutil.DecodeHexWithLength(proof, 32)
+		if err != nil {
+			return nil, server.NewDecodeError(err, "CommitmentInclusionProof")
+		}
+		commitmentInclusionProof = append(commitmentInclusionProof, proofBytes)
+	}
+
+	bsc := &eth.BlobSidecar{
+		Index:                    index,
+		Blob:                     blob,
+		KzgCommitment:            kzgCommitment,
+		KzgProof:                 kzgProof,
+		SignedBlockHeader:        header,
+		CommitmentInclusionProof: commitmentInclusionProof,
+	}
+
+	return bsc, nil
+}

api/server/structs/conversions_block.go

@@ -20,6 +20,9 @@ import (
 var ErrUnsupportedConversion = errors.New("Could not determine api struct type to use for value")
 
 func (h *SignedBeaconBlockHeader) ToConsensus() (*eth.SignedBeaconBlockHeader, error) {
+	if h == nil {
+		return nil, errNilValue
+	}
 	msg, err := h.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -36,6 +39,9 @@ func (h *SignedBeaconBlockHeader) ToConsensus() (*eth.SignedBeaconBlockHeader, e
 }
 
 func (h *BeaconBlockHeader) ToConsensus() (*eth.BeaconBlockHeader, error) {
+	if h == nil {
+		return nil, errNilValue
+	}
 	s, err := strconv.ParseUint(h.Slot, 10, 64)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Slot")
@@ -2548,6 +2554,8 @@ func SignedBeaconBlockMessageJsoner(block interfaces.ReadOnlySignedBeaconBlock)
 		return SignedBlindedBeaconBlockDenebFromConsensus(pbStruct)
 	case *eth.SignedBeaconBlockDeneb:
 		return SignedBeaconBlockDenebFromConsensus(pbStruct)
+	case *eth.SignedBlindedBeaconBlockElectra:
+		return SignedBlindedBeaconBlockElectraFromConsensus(pbStruct)
 	case *eth.SignedBeaconBlockElectra:
 		return SignedBeaconBlockElectraFromConsensus(pbStruct)
 	default:

api/server/structs/conversions_lightclient.go

@@ -84,6 +84,11 @@ func syncAggregateToJSON(input *v1.SyncAggregate) *SyncAggregate {
 }
 
 func lightClientHeaderContainerToJSON(container *v2.LightClientHeaderContainer) (json.RawMessage, error) {
+	// In the case that a finalizedHeader is nil.
+	if container == nil {
+		return nil, nil
+	}
+
 	beacon, err := container.GetBeacon()
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get beacon block header")

api/server/structs/endpoints_blob.go

@@ -12,3 +12,12 @@ type Sidecar struct {
 	KzgProof                 string                   `json:"kzg_proof"`
 	CommitmentInclusionProof []string                 `json:"kzg_commitment_inclusion_proof"`
 }
+
+type BlobSidecars struct {
+	Sidecars []*Sidecar `json:"sidecars"`
+}
+
+type PublishBlobsRequest struct {
+	BlobSidecars *BlobSidecars `json:"blob_sidecars"`
+	BlockRoot    string        `json:"block_root"`
+}

async/event/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "feed.go",
+        "interface.go",
         "subscription.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/async/event",

async/event/feed.go

@@ -22,3 +22,4 @@ import (
 
 // Feed is a re-export of the go-ethereum event feed.
 type Feed = geth_event.Feed
+type Subscription = geth_event.Subscription

async/event/interface.go

@@ -0,0 +1,8 @@
+package event
+
+// SubscriberSender is an abstract representation of an *event.Feed
+// to use in describing types that accept or return an *event.Feed.
+type SubscriberSender interface {
+	Subscribe(channel interface{}) Subscription
+	Send(value interface{}) (nsent int)
+}

async/event/subscription.go

@@ -28,25 +28,6 @@ import (
 // request backoff time.
 const waitQuotient = 10
 
-// Subscription represents a stream of events. The carrier of the events is typically a
-// channel, but isn't part of the interface.
-//
-// Subscriptions can fail while established. Failures are reported through an error
-// channel. It receives a value if there is an issue with the subscription (e.g. the
-// network connection delivering the events has been closed). Only one value will ever be
-// sent.
-//
-// The error channel is closed when the subscription ends successfully (i.e. when the
-// source of events is closed). It is also closed when Unsubscribe is called.
-//
-// The Unsubscribe method cancels the sending of events. You must call Unsubscribe in all
-// cases to ensure that resources related to the subscription are released. It can be
-// called any number of times.
-type Subscription interface {
-	Err() <-chan error // returns the error channel
-	Unsubscribe()      // cancels sending of events, closing the error channel
-}
-
 // NewSubscription runs a producer function as a subscription in a new goroutine. The
 // channel given to the producer is closed when Unsubscribe is called. If fn returns an
 // error, it is sent on the subscription's error channel.

beacon-chain/blockchain/execution_engine.go

@@ -2,7 +2,6 @@ package blockchain
 
 import (
 	"context"
-	"crypto/sha256"
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -28,8 +27,6 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-const blobCommitmentVersionKZG uint8 = 0x01
-
 var defaultLatestValidHash = bytesutil.PadTo([]byte{0xff}, 32)
 
 // notifyForkchoiceUpdate signals execution engine the fork choice updates. Execution engine should:
@@ -402,13 +399,7 @@ func kzgCommitmentsToVersionedHashes(body interfaces.ReadOnlyBeaconBlockBody) ([
 
 	versionedHashes := make([]common.Hash, len(commitments))
 	for i, commitment := range commitments {
-		versionedHashes[i] = ConvertKzgCommitmentToVersionedHash(commitment)
+		versionedHashes[i] = primitives.ConvertKzgCommitmentToVersionedHash(commitment)
 	}
 	return versionedHashes, nil
 }
-
-func ConvertKzgCommitmentToVersionedHash(commitment []byte) common.Hash {
-	versionedHash := sha256.Sum256(commitment)
-	versionedHash[0] = blobCommitmentVersionKZG
-	return versionedHash
-}

beacon-chain/blockchain/process_block_helpers.go

@@ -162,6 +162,10 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 	postState state.BeaconState) (int, error) {
 	// Get attested state
 	attestedRoot := signed.Block().ParentRoot()
+	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
+	if err != nil {
+		return 0, errors.Wrap(err, "could not get attested block")
+	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get attested state")
@@ -183,6 +187,7 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 		postState,
 		signed,
 		attestedState,
+		attestedBlock,
 		finalizedBlock,
 	)
 
@@ -208,6 +213,10 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 	postState state.BeaconState) (int, error) {
 	// Get attested state
 	attestedRoot := signed.Block().ParentRoot()
+	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
+	if err != nil {
+		return 0, errors.Wrap(err, "could not get attested block")
+	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get attested state")
@@ -218,6 +227,7 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 		postState,
 		signed,
 		attestedState,
+		attestedBlock,
 	)
 
 	if err != nil {

beacon-chain/blockchain/setup_test.go

@@ -32,7 +32,7 @@ type mockBeaconNode struct {
 }
 
 // StateFeed mocks the same method in the beacon node.
-func (mbn *mockBeaconNode) StateFeed() *event.Feed {
+func (mbn *mockBeaconNode) StateFeed() event.SubscriberSender {
 	mbn.mu.Lock()
 	defer mbn.mu.Unlock()
 	if mbn.stateFeed == nil {

beacon-chain/blockchain/testing/mock.go

@@ -98,6 +98,44 @@ func (s *ChainService) BlockNotifier() blockfeed.Notifier {
 	return s.blockNotifier
 }
 
+type EventFeedWrapper struct {
+	feed       *event.Feed
+	subscribed chan struct{} // this channel is closed once a subscription is made
+}
+
+func (w *EventFeedWrapper) Subscribe(channel interface{}) event.Subscription {
+	select {
+	case <-w.subscribed:
+		break // already closed
+	default:
+		close(w.subscribed)
+	}
+	return w.feed.Subscribe(channel)
+}
+
+func (w *EventFeedWrapper) Send(value interface{}) int {
+	return w.feed.Send(value)
+}
+
+// WaitForSubscription allows test to wait for the feed to have a subscription before beginning to send events.
+func (w *EventFeedWrapper) WaitForSubscription(ctx context.Context) error {
+	select {
+	case <-w.subscribed:
+		return nil
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}
+
+var _ event.SubscriberSender = &EventFeedWrapper{}
+
+func NewEventFeedWrapper() *EventFeedWrapper {
+	return &EventFeedWrapper{
+		feed:       new(event.Feed),
+		subscribed: make(chan struct{}),
+	}
+}
+
 // MockBlockNotifier mocks the block notifier.
 type MockBlockNotifier struct {
 	feed *event.Feed
@@ -131,7 +169,7 @@ func (msn *MockStateNotifier) ReceivedEvents() []*feed.Event {
 }
 
 // StateFeed returns a state feed.
-func (msn *MockStateNotifier) StateFeed() *event.Feed {
+func (msn *MockStateNotifier) StateFeed() event.SubscriberSender {
 	msn.feedLock.Lock()
 	defer msn.feedLock.Unlock()
 
@@ -159,6 +197,23 @@ func (msn *MockStateNotifier) StateFeed() *event.Feed {
 	return msn.feed
 }
 
+// NewSimpleStateNotifier makes a state feed without the custom mock feed machinery.
+func NewSimpleStateNotifier() *MockStateNotifier {
+	return &MockStateNotifier{feed: new(event.Feed)}
+}
+
+type SimpleNotifier struct {
+	Feed event.SubscriberSender
+}
+
+func (n *SimpleNotifier) StateFeed() event.SubscriberSender {
+	return n.Feed
+}
+
+func (n *SimpleNotifier) OperationFeed() event.SubscriberSender {
+	return n.Feed
+}
+
 // OperationNotifier mocks the same method in the chain service.
 func (s *ChainService) OperationNotifier() opfeed.Notifier {
 	if s.opNotifier == nil {
@@ -173,7 +228,7 @@ type MockOperationNotifier struct {
 }
 
 // OperationFeed returns an operation feed.
-func (mon *MockOperationNotifier) OperationFeed() *event.Feed {
+func (mon *MockOperationNotifier) OperationFeed() event.SubscriberSender {
 	if mon.feed == nil {
 		mon.feed = new(event.Feed)
 	}

beacon-chain/core/feed/operation/notifier.go

@@ -4,5 +4,5 @@ import "github.com/prysmaticlabs/prysm/v5/async/event"
 
 // Notifier interface defines the methods of the service that provides beacon block operation updates to consumers.
 type Notifier interface {
-	OperationFeed() *event.Feed
+	OperationFeed() event.SubscriberSender
 }

beacon-chain/core/feed/state/notifier.go

@@ -4,5 +4,5 @@ import "github.com/prysmaticlabs/prysm/v5/async/event"
 
 // Notifier interface defines the methods of the service that provides state updates to consumers.
 type Notifier interface {
-	StateFeed() *event.Feed
+	StateFeed() event.SubscriberSender
 }

beacon-chain/core/light-client/BUILD.bazel

@@ -12,12 +12,10 @@ go_library(
         "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
-        "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/eth/v2:go_default_library",
-        "//proto/migration:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -29,11 +27,13 @@ go_test(
     srcs = ["lightclient_test.go"],
     deps = [
         ":go_default_library",
-        "//config/params:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
-        "//consensus-types/primitives:go_default_library",
+        "//encoding/ssz:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/core/light-client/lightclient.go

@@ -13,15 +13,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/encoding/ssz"
-	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	v11 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-	"github.com/prysmaticlabs/prysm/v5/proto/migration"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
-
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 )
 
 const (
@@ -29,16 +25,6 @@ const (
 	executionBranchNumOfLeaves = 4
 )
 
-// createLightClientFinalityUpdate - implements https://github.com/ethereum/consensus-specs/blob/3d235740e5f1e641d3b160c8688f26e7dc5a1894/specs/altair/light-client/full-node.md#create_light_client_finality_update
-// def create_light_client_finality_update(update: LightClientUpdate) -> LightClientFinalityUpdate:
-//
-//	return LightClientFinalityUpdate(
-//	    attested_header=update.attested_header,
-//	    finalized_header=update.finalized_header,
-//	    finality_branch=update.finality_branch,
-//	    sync_aggregate=update.sync_aggregate,
-//	    signature_slot=update.signature_slot,
-//	)
 func createLightClientFinalityUpdate(update *ethpbv2.LightClientUpdate) *ethpbv2.LightClientFinalityUpdate {
 	finalityUpdate := &ethpbv2.LightClientFinalityUpdate{
 		AttestedHeader:  update.AttestedHeader,
@@ -51,14 +37,6 @@ func createLightClientFinalityUpdate(update *ethpbv2.LightClientUpdate) *ethpbv2
 	return finalityUpdate
 }
 
-// createLightClientOptimisticUpdate - implements https://github.com/ethereum/consensus-specs/blob/3d235740e5f1e641d3b160c8688f26e7dc5a1894/specs/altair/light-client/full-node.md#create_light_client_optimistic_update
-// def create_light_client_optimistic_update(update: LightClientUpdate) -> LightClientOptimisticUpdate:
-//
-//	return LightClientOptimisticUpdate(
-//	    attested_header=update.attested_header,
-//	    sync_aggregate=update.sync_aggregate,
-//	    signature_slot=update.signature_slot,
-//	)
 func createLightClientOptimisticUpdate(update *ethpbv2.LightClientUpdate) *ethpbv2.LightClientOptimisticUpdate {
 	optimisticUpdate := &ethpbv2.LightClientOptimisticUpdate{
 		AttestedHeader: update.AttestedHeader,
@@ -74,9 +52,10 @@ func NewLightClientFinalityUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 	finalizedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*ethpbv2.LightClientFinalityUpdate, error) {
-	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, finalizedBlock)
+	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
 		return nil, err
 	}
@@ -89,8 +68,9 @@ func NewLightClientOptimisticUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*ethpbv2.LightClientOptimisticUpdate, error) {
-	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, nil)
+	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -98,68 +78,12 @@ func NewLightClientOptimisticUpdateFromBeaconState(
 	return createLightClientOptimisticUpdate(update), nil
 }
 
-// NewLightClientUpdateFromBeaconState implements https://github.com/ethereum/consensus-specs/blob/d70dcd9926a4bbe987f1b4e65c3e05bd029fcfb8/specs/altair/light-client/full-node.md#create_light_client_update
-// def create_light_client_update(state: BeaconState,
-//
-//	                           block: SignedBeaconBlock,
-//	                           attested_state: BeaconState,
-//	                           finalized_block: Optional[SignedBeaconBlock]) -> LightClientUpdate:
-//	assert compute_epoch_at_slot(attested_state.slot) >= ALTAIR_FORK_EPOCH
-//	assert sum(block.message.body.sync_aggregate.sync_committee_bits) >= MIN_SYNC_COMMITTEE_PARTICIPANTS
-//
-//	assert state.slot == state.latest_block_header.slot
-//	header = state.latest_block_header.copy()
-//	header.state_root = hash_tree_root(state)
-//	assert hash_tree_root(header) == hash_tree_root(block.message)
-//	update_signature_period = compute_sync_committee_period(compute_epoch_at_slot(block.message.slot))
-//
-//	assert attested_state.slot == attested_state.latest_block_header.slot
-//	attested_header = attested_state.latest_block_header.copy()
-//	attested_header.state_root = hash_tree_root(attested_state)
-//	assert hash_tree_root(attested_header) == block.message.parent_root
-//	update_attested_period = compute_sync_committee_period(compute_epoch_at_slot(attested_header.slot))
-//
-//	# `next_sync_committee` is only useful if the message is signed by the current sync committee
-//	if update_attested_period == update_signature_period:
-//	    next_sync_committee = attested_state.next_sync_committee
-//	    next_sync_committee_branch = compute_merkle_proof_for_state(attested_state, NEXT_SYNC_COMMITTEE_INDEX)
-//	else:
-//	    next_sync_committee = SyncCommittee()
-//	    next_sync_committee_branch = [Bytes32() for _ in range(floorlog2(NEXT_SYNC_COMMITTEE_INDEX))]
-//
-//	# Indicate finality whenever possible
-//	if finalized_block is not None:
-//	    if finalized_block.message.slot != GENESIS_SLOT:
-//	        finalized_header = BeaconBlockHeader(
-//	            slot=finalized_block.message.slot,
-//	            proposer_index=finalized_block.message.proposer_index,
-//	            parent_root=finalized_block.message.parent_root,
-//	            state_root=finalized_block.message.state_root,
-//	            body_root=hash_tree_root(finalized_block.message.body),
-//	        )
-//	        assert hash_tree_root(finalized_header) == attested_state.finalized_checkpoint.root
-//	    else:
-//	        assert attested_state.finalized_checkpoint.root == Bytes32()
-//	        finalized_header = BeaconBlockHeader()
-//	    finality_branch = compute_merkle_proof_for_state(attested_state, FINALIZED_ROOT_INDEX)
-//	else:
-//	    finalized_header = BeaconBlockHeader()
-//	    finality_branch = [Bytes32() for _ in range(floorlog2(FINALIZED_ROOT_INDEX))]
-//
-//	return LightClientUpdate(
-//	    attested_header=attested_header,
-//	    next_sync_committee=next_sync_committee,
-//	    next_sync_committee_branch=next_sync_committee_branch,
-//	    finalized_header=finalized_header,
-//	    finality_branch=finality_branch,
-//	    sync_aggregate=block.message.body.sync_aggregate,
-//	    signature_slot=block.message.slot,
-//	)
 func NewLightClientUpdateFromBeaconState(
 	ctx context.Context,
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 	finalizedBlock interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientUpdate, error) {
 	// assert compute_epoch_at_slot(attested_state.slot) >= ALTAIR_FORK_EPOCH
 	attestedEpoch := slots.ToEpoch(attestedState.Slot())
@@ -223,73 +147,30 @@ func NewLightClientUpdateFromBeaconState(
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get attested header root")
 	}
-	if attestedHeaderRoot != block.Block().ParentRoot() {
-		return nil, fmt.Errorf("attested header root %#x not equal to block parent root %#x", attestedHeaderRoot, block.Block().ParentRoot())
+	attestedBlockRoot, err := attestedBlock.Block().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get attested block root")
+	}
+	// assert hash_tree_root(attested_header) == hash_tree_root(attested_block.message) == block.message.parent_root
+	if attestedHeaderRoot != block.Block().ParentRoot() || attestedHeaderRoot != attestedBlockRoot {
+		return nil, fmt.Errorf("attested header root %#x not equal to block parent root %#x or attested block root %#x", attestedHeaderRoot, block.Block().ParentRoot(), attestedBlockRoot)
 	}
 
-	// update_attested_period = compute_sync_committee_period(compute_epoch_at_slot(attested_header.slot))
-	updateAttestedPeriod := slots.SyncCommitteePeriod(slots.ToEpoch(attestedHeader.Slot))
+	// update_attested_period = compute_sync_committee_period_at_slot(attested_block.message.slot)
+	updateAttestedPeriod := slots.SyncCommitteePeriod(slots.ToEpoch(attestedBlock.Block().Slot()))
 
 	// update = LightClientUpdate()
-	result, err := createDefaultLightClientUpdate(block.Block().Version())
+	result, err := createDefaultLightClientUpdate()
 	if err != nil {
 		return nil, errors.Wrap(err, "could not create default light client update")
 	}
 
 	// update.attested_header = block_to_light_client_header(attested_block)
-	blockHeader := &ethpbv1.BeaconBlockHeader{
-		Slot:          attestedHeader.Slot,
-		ProposerIndex: attestedHeader.ProposerIndex,
-		ParentRoot:    attestedHeader.ParentRoot,
-		StateRoot:     attestedHeader.StateRoot,
-		BodyRoot:      attestedHeader.BodyRoot,
-	}
-	switch block.Block().Version() {
-	case version.Altair, version.Bellatrix:
-		result.AttestedHeader = &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
-				HeaderAltair: &ethpbv2.LightClientHeader{Beacon: blockHeader},
-			},
-		}
-	case version.Capella:
-		executionPayloadHeader, err := getExecutionPayloadHeaderCapella(block)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get execution payload header")
-		}
-		executionPayloadProof, err := blocks.PayloadProof(ctx, block.Block())
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get execution payload proof")
-		}
-		result.AttestedHeader = &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
-				HeaderCapella: &ethpbv2.LightClientHeaderCapella{
-					Beacon:          blockHeader,
-					Execution:       executionPayloadHeader,
-					ExecutionBranch: executionPayloadProof,
-				},
-			},
-		}
-	case version.Deneb:
-		executionPayloadHeader, err := getExecutionPayloadHeaderDeneb(block)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get execution payload header")
-		}
-		executionPayloadProof, err := blocks.PayloadProof(ctx, block.Block())
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get execution payload proof")
-		}
-		result.AttestedHeader = &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
-				HeaderDeneb: &ethpbv2.LightClientHeaderDeneb{
-					Beacon:          blockHeader,
-					Execution:       executionPayloadHeader,
-					ExecutionBranch: executionPayloadProof,
-				},
-			},
-		}
-	default:
-		return nil, fmt.Errorf("unsupported block version %s", version.String(block.Block().Version()))
+	attestedLightClientHeader, err := BlockToLightClientHeader(attestedBlock)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get attested light client header")
 	}
+	result.AttestedHeader = attestedLightClientHeader
 
 	// if update_attested_period == update_signature_period
 	if updateAttestedPeriod == updateSignaturePeriod {
@@ -319,70 +200,11 @@ func NewLightClientUpdateFromBeaconState(
 		// if finalized_block.message.slot != GENESIS_SLOT
 		if finalizedBlock.Block().Slot() != 0 {
 			// update.finalized_header = block_to_light_client_header(finalized_block)
-			v1alpha1FinalizedHeader, err := finalizedBlock.Header()
+			finalizedLightClientHeader, err := BlockToLightClientHeader(finalizedBlock)
 			if err != nil {
-				return nil, errors.Wrap(err, "could not get finalized header")
-			}
-			finalizedHeader := migration.V1Alpha1SignedHeaderToV1(v1alpha1FinalizedHeader).GetMessage()
-			finalizedHeaderRoot, err := finalizedHeader.HashTreeRoot()
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get finalized header root")
-			}
-			switch block.Block().Version() {
-			case version.Altair, version.Bellatrix:
-				result.FinalizedHeader = &ethpbv2.LightClientHeaderContainer{
-					Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
-						HeaderAltair: &ethpbv2.LightClientHeader{Beacon: finalizedHeader},
-					},
-				}
-			case version.Capella:
-				executionPayloadHeader, err := getExecutionPayloadHeaderCapella(finalizedBlock)
-				if err != nil {
-					return nil, errors.Wrap(err, "could not get execution payload header")
-				}
-				executionPayloadProof, err := blocks.PayloadProof(ctx, finalizedBlock.Block())
-				if err != nil {
-					return nil, errors.Wrap(err, "could not get execution payload proof")
-				}
-				result.FinalizedHeader = &ethpbv2.LightClientHeaderContainer{
-					Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
-						HeaderCapella: &ethpbv2.LightClientHeaderCapella{
-							Beacon:          finalizedHeader,
-							Execution:       executionPayloadHeader,
-							ExecutionBranch: executionPayloadProof,
-						},
-					},
-				}
-			case version.Deneb:
-				executionPayloadHeader, err := getExecutionPayloadHeaderDeneb(finalizedBlock)
-				if err != nil {
-					return nil, errors.Wrap(err, "could not get execution payload header")
-				}
-				executionPayloadProof, err := blocks.PayloadProof(ctx, finalizedBlock.Block())
-				if err != nil {
-					return nil, errors.Wrap(err, "could not get execution payload proof")
-				}
-				result.FinalizedHeader = &ethpbv2.LightClientHeaderContainer{
-					Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
-						HeaderDeneb: &ethpbv2.LightClientHeaderDeneb{
-							Beacon:          finalizedHeader,
-							Execution:       executionPayloadHeader,
-							ExecutionBranch: executionPayloadProof,
-						},
-					},
-				}
-			default:
-				return nil, fmt.Errorf("unsupported block version %s", version.String(block.Block().Version()))
-			}
-
-			// assert hash_tree_root(update.finalized_header.beacon) == attested_state.finalized_checkpoint.root
-			if finalizedHeaderRoot != bytesutil.ToBytes32(attestedState.FinalizedCheckpoint().Root) {
-				return nil, fmt.Errorf(
-					"finalized header root %#x not equal to attested finalized checkpoint root %#x",
-					finalizedHeaderRoot,
-					bytesutil.ToBytes32(attestedState.FinalizedCheckpoint().Root),
-				)
+				return nil, errors.Wrap(err, "could not get finalized light client header")
 			}
+			result.FinalizedHeader = finalizedLightClientHeader
 		} else {
 			// assert attested_state.finalized_checkpoint.root == Bytes32()
 			if !bytes.Equal(attestedState.FinalizedCheckpoint().Root, make([]byte, 32)) {
@@ -411,7 +233,7 @@ func NewLightClientUpdateFromBeaconState(
 	return result, nil
 }
 
-func createDefaultLightClientUpdate(v int) (*ethpbv2.LightClientUpdate, error) {
+func createDefaultLightClientUpdate() (*ethpbv2.LightClientUpdate, error) {
 	syncCommitteeSize := params.BeaconConfig().SyncCommitteeSize
 	pubKeys := make([][]byte, syncCommitteeSize)
 	for i := uint64(0); i < syncCommitteeSize; i++ {
@@ -421,218 +243,26 @@ func createDefaultLightClientUpdate(v int) (*ethpbv2.LightClientUpdate, error) {
 		Pubkeys:         pubKeys,
 		AggregatePubkey: make([]byte, fieldparams.BLSPubkeyLength),
 	}
-	nextSyncCommitteeBranch := make([][]byte, fieldparams.NextSyncCommitteeBranchDepth)
-	for i := 0; i < fieldparams.NextSyncCommitteeBranchDepth; i++ {
+	nextSyncCommitteeBranch := make([][]byte, fieldparams.SyncCommitteeBranchDepth)
+	for i := 0; i < fieldparams.SyncCommitteeBranchDepth; i++ {
 		nextSyncCommitteeBranch[i] = make([]byte, fieldparams.RootLength)
 	}
 	executionBranch := make([][]byte, executionBranchNumOfLeaves)
 	for i := 0; i < executionBranchNumOfLeaves; i++ {
 		executionBranch[i] = make([]byte, 32)
 	}
-	finalizedBlockHeader := &ethpbv1.BeaconBlockHeader{
-		Slot:          0,
-		ProposerIndex: 0,
-		ParentRoot:    make([]byte, 32),
-		StateRoot:     make([]byte, 32),
-		BodyRoot:      make([]byte, 32),
-	}
 	finalityBranch := make([][]byte, FinalityBranchNumOfLeaves)
 	for i := 0; i < FinalityBranchNumOfLeaves; i++ {
 		finalityBranch[i] = make([]byte, 32)
 	}
 
-	var finalizedHeader *ethpbv2.LightClientHeaderContainer
-	switch v {
-	case version.Altair, version.Bellatrix:
-		finalizedHeader = &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
-				HeaderAltair: &ethpbv2.LightClientHeader{
-					Beacon: finalizedBlockHeader,
-				},
-			},
-		}
-	case version.Capella:
-		finalizedHeader = &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
-				HeaderCapella: &ethpbv2.LightClientHeaderCapella{
-					Beacon:          finalizedBlockHeader,
-					Execution:       createEmptyExecutionPayloadHeaderCapella(),
-					ExecutionBranch: executionBranch,
-				},
-			},
-		}
-	case version.Deneb:
-		finalizedHeader = &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
-				HeaderDeneb: &ethpbv2.LightClientHeaderDeneb{
-					Beacon:          finalizedBlockHeader,
-					Execution:       createEmptyExecutionPayloadHeaderDeneb(),
-					ExecutionBranch: executionBranch,
-				},
-			},
-		}
-	default:
-		return nil, fmt.Errorf("unsupported block version %s", version.String(v))
-	}
-
 	return &ethpbv2.LightClientUpdate{
 		NextSyncCommittee:       nextSyncCommittee,
 		NextSyncCommitteeBranch: nextSyncCommitteeBranch,
-		FinalizedHeader:         finalizedHeader,
 		FinalityBranch:          finalityBranch,
 	}, nil
 }
 
-func createEmptyExecutionPayloadHeaderCapella() *enginev1.ExecutionPayloadHeaderCapella {
-	return &enginev1.ExecutionPayloadHeaderCapella{
-		ParentHash:       make([]byte, 32),
-		FeeRecipient:     make([]byte, 20),
-		StateRoot:        make([]byte, 32),
-		ReceiptsRoot:     make([]byte, 32),
-		LogsBloom:        make([]byte, 256),
-		PrevRandao:       make([]byte, 32),
-		BlockNumber:      0,
-		GasLimit:         0,
-		GasUsed:          0,
-		Timestamp:        0,
-		ExtraData:        make([]byte, 32),
-		BaseFeePerGas:    make([]byte, 32),
-		BlockHash:        make([]byte, 32),
-		TransactionsRoot: make([]byte, 32),
-		WithdrawalsRoot:  make([]byte, 32),
-	}
-}
-
-func createEmptyExecutionPayloadHeaderDeneb() *enginev1.ExecutionPayloadHeaderDeneb {
-	return &enginev1.ExecutionPayloadHeaderDeneb{
-		ParentHash:       make([]byte, 32),
-		FeeRecipient:     make([]byte, 20),
-		StateRoot:        make([]byte, 32),
-		ReceiptsRoot:     make([]byte, 32),
-		LogsBloom:        make([]byte, 256),
-		PrevRandao:       make([]byte, 32),
-		BlockNumber:      0,
-		GasLimit:         0,
-		GasUsed:          0,
-		Timestamp:        0,
-		ExtraData:        make([]byte, 32),
-		BaseFeePerGas:    make([]byte, 32),
-		BlockHash:        make([]byte, 32),
-		TransactionsRoot: make([]byte, 32),
-		WithdrawalsRoot:  make([]byte, 32),
-	}
-}
-
-func getExecutionPayloadHeaderCapella(block interfaces.ReadOnlySignedBeaconBlock) (*enginev1.ExecutionPayloadHeaderCapella, error) {
-	payloadInterface, err := block.Block().Body().Execution()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get execution data")
-	}
-	transactionsRoot, err := payloadInterface.TransactionsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		transactions, err := payloadInterface.Transactions()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions")
-		}
-		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions root")
-		}
-		transactionsRoot = transactionsRootArray[:]
-	} else if err != nil {
-		return nil, errors.Wrap(err, "could not get transactions root")
-	}
-	withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		withdrawals, err := payloadInterface.Withdrawals()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals")
-		}
-		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals root")
-		}
-		withdrawalsRoot = withdrawalsRootArray[:]
-	} else if err != nil {
-		return nil, errors.Wrap(err, "could not get withdrawals root")
-	}
-
-	execution := &enginev1.ExecutionPayloadHeaderCapella{
-		ParentHash:       payloadInterface.ParentHash(),
-		FeeRecipient:     payloadInterface.FeeRecipient(),
-		StateRoot:        payloadInterface.StateRoot(),
-		ReceiptsRoot:     payloadInterface.ReceiptsRoot(),
-		LogsBloom:        payloadInterface.LogsBloom(),
-		PrevRandao:       payloadInterface.PrevRandao(),
-		BlockNumber:      payloadInterface.BlockNumber(),
-		GasLimit:         payloadInterface.GasLimit(),
-		GasUsed:          payloadInterface.GasUsed(),
-		Timestamp:        payloadInterface.Timestamp(),
-		ExtraData:        payloadInterface.ExtraData(),
-		BaseFeePerGas:    payloadInterface.BaseFeePerGas(),
-		BlockHash:        payloadInterface.BlockHash(),
-		TransactionsRoot: transactionsRoot,
-		WithdrawalsRoot:  withdrawalsRoot,
-	}
-
-	return execution, nil
-}
-
-func getExecutionPayloadHeaderDeneb(block interfaces.ReadOnlySignedBeaconBlock) (*enginev1.ExecutionPayloadHeaderDeneb, error) {
-	payloadInterface, err := block.Block().Body().Execution()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get execution data")
-	}
-	transactionsRoot, err := payloadInterface.TransactionsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		transactions, err := payloadInterface.Transactions()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions")
-		}
-		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions root")
-		}
-		transactionsRoot = transactionsRootArray[:]
-	} else if err != nil {
-		return nil, errors.Wrap(err, "could not get transactions root")
-	}
-	withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		withdrawals, err := payloadInterface.Withdrawals()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals")
-		}
-		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals root")
-		}
-		withdrawalsRoot = withdrawalsRootArray[:]
-	} else if err != nil {
-		return nil, errors.Wrap(err, "could not get withdrawals root")
-	}
-
-	execution := &enginev1.ExecutionPayloadHeaderDeneb{
-		ParentHash:       payloadInterface.ParentHash(),
-		FeeRecipient:     payloadInterface.FeeRecipient(),
-		StateRoot:        payloadInterface.StateRoot(),
-		ReceiptsRoot:     payloadInterface.ReceiptsRoot(),
-		LogsBloom:        payloadInterface.LogsBloom(),
-		PrevRandao:       payloadInterface.PrevRandao(),
-		BlockNumber:      payloadInterface.BlockNumber(),
-		GasLimit:         payloadInterface.GasLimit(),
-		GasUsed:          payloadInterface.GasUsed(),
-		Timestamp:        payloadInterface.Timestamp(),
-		ExtraData:        payloadInterface.ExtraData(),
-		BaseFeePerGas:    payloadInterface.BaseFeePerGas(),
-		BlockHash:        payloadInterface.BlockHash(),
-		TransactionsRoot: transactionsRoot,
-		WithdrawalsRoot:  withdrawalsRoot,
-	}
-
-	return execution, nil
-}
-
 func ComputeTransactionsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 	transactionsRoot, err := payload.TransactionsRoot()
 	if errors.Is(err, consensus_types.ErrUnsupportedField) {
@@ -669,8 +299,45 @@ func ComputeWithdrawalsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 	return withdrawalsRoot, nil
 }
 
-func BlockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeader, error) {
-	if block.Version() != version.Altair {
+func BlockToLightClientHeader(block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderContainer, error) {
+	switch block.Version() {
+	case version.Altair, version.Bellatrix:
+		altairHeader, err := blockToLightClientHeaderAltair(block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get header")
+		}
+		return &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
+				HeaderAltair: altairHeader,
+			},
+		}, nil
+	case version.Capella:
+		capellaHeader, err := blockToLightClientHeaderCapella(context.Background(), block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get capella header")
+		}
+		return &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
+				HeaderCapella: capellaHeader,
+			},
+		}, nil
+	case version.Deneb, version.Electra:
+		denebHeader, err := blockToLightClientHeaderDeneb(context.Background(), block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get header")
+		}
+		return &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
+				HeaderDeneb: denebHeader,
+			},
+		}, nil
+	default:
+		return nil, fmt.Errorf("unsupported block version %s", version.String(block.Version()))
+	}
+}
+
+func blockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeader, error) {
+	if block.Version() < version.Altair {
 		return nil, fmt.Errorf("block version is %s instead of Altair", version.String(block.Version()))
 	}
 
@@ -692,8 +359,8 @@ func BlockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock)
 	}, nil
 }
 
-func BlockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderCapella, error) {
-	if block.Version() != version.Capella {
+func blockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderCapella, error) {
+	if block.Version() < version.Capella {
 		return nil, fmt.Errorf("block version is %s instead of Capella", version.String(block.Version()))
 	}
 
@@ -754,9 +421,9 @@ func BlockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadO
 	}, nil
 }
 
-func BlockToLightClientHeaderDeneb(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderDeneb, error) {
-	if block.Version() != version.Deneb {
-		return nil, fmt.Errorf("block version is %s instead of Deneb", version.String(block.Version()))
+func blockToLightClientHeaderDeneb(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderDeneb, error) {
+	if block.Version() < version.Deneb {
+		return nil, fmt.Errorf("block version is %s instead of Deneb/Electra", version.String(block.Version()))
 	}
 
 	payload, err := block.Block().Body().Execution()

beacon-chain/execution/service_test.go

@@ -73,7 +73,7 @@ type goodNotifier struct {
 	MockStateFeed *event.Feed
 }
 
-func (g *goodNotifier) StateFeed() *event.Feed {
+func (g *goodNotifier) StateFeed() event.SubscriberSender {
 	if g.MockStateFeed == nil {
 		g.MockStateFeed = new(event.Feed)
 	}

beacon-chain/node/node.go

@@ -398,7 +398,7 @@ func initSyncWaiter(ctx context.Context, complete chan struct{}) func() error {
 }
 
 // StateFeed implements statefeed.Notifier.
-func (b *BeaconNode) StateFeed() *event.Feed {
+func (b *BeaconNode) StateFeed() event.SubscriberSender {
 	return b.stateFeed
 }
 
@@ -408,7 +408,7 @@ func (b *BeaconNode) BlockFeed() *event.Feed {
 }
 
 // OperationFeed implements opfeed.Notifier.
-func (b *BeaconNode) OperationFeed() *event.Feed {
+func (b *BeaconNode) OperationFeed() event.SubscriberSender {
 	return b.opFeed
 }
 

beacon-chain/rpc/BUILD.bazel

@@ -89,5 +89,6 @@ go_test(
         "//testing/require:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
+        "@org_golang_x_exp//maps:go_default_library",
     ],
 )

beacon-chain/rpc/endpoints.go

@@ -773,6 +773,15 @@ func (s *Service) beaconEndpoints(
 			handler: server.GetValidatorBalances,
 			methods: []string{http.MethodGet, http.MethodPost},
 		},
+		{
+			template: "/eth/v1/beacon/deposit_snapshot",
+			name:     namespace + ".GetDepositSnapshot",
+			middleware: []middleware.Middleware{
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType}),
+			},
+			handler: server.GetDepositSnapshot,
+			methods: []string{http.MethodGet},
+		},
 	}
 }
 
@@ -942,6 +951,8 @@ func (s *Service) prysmBeaconEndpoints(
 		ChainInfoFetcher:      s.cfg.ChainInfoFetcher,
 		FinalizationFetcher:   s.cfg.FinalizationFetcher,
 		CoreService:           coreService,
+		Broadcaster:           s.cfg.Broadcaster,
+		BlobReceiver:          s.cfg.BlobReceiver,
 	}
 
 	const namespace = "prysm.beacon"
@@ -992,6 +1003,16 @@ func (s *Service) prysmBeaconEndpoints(
 			handler: server.GetChainHead,
 			methods: []string{http.MethodGet},
 		},
+		{
+			template: "/prysm/v1/beacon/blobs",
+			name:     namespace + ".PublishBlobs",
+			middleware: []middleware.Middleware{
+				middleware.ContentTypeHandler([]string{api.JsonMediaType}),
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType}),
+			},
+			handler: server.PublishBlobs,
+			methods: []string{http.MethodPost},
+		},
 	}
 }
 

beacon-chain/rpc/endpoints_test.go

@@ -2,9 +2,11 @@ package rpc
 
 import (
 	"net/http"
+	"slices"
 	"testing"
 
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+	"golang.org/x/exp/maps"
 )
 
 func Test_endpoints(t *testing.T) {
@@ -31,7 +33,6 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v2/beacon/blinded_blocks":                              {http.MethodPost},
 		"/eth/v1/beacon/blocks":                                      {http.MethodPost},
 		"/eth/v2/beacon/blocks":                                      {http.MethodPost},
-		"/eth/v1/beacon/blocks/{block_id}":                           {http.MethodGet},
 		"/eth/v2/beacon/blocks/{block_id}":                           {http.MethodGet},
 		"/eth/v1/beacon/blocks/{block_id}/root":                      {http.MethodGet},
 		"/eth/v1/beacon/blocks/{block_id}/attestations":              {http.MethodGet},
@@ -69,7 +70,6 @@ func Test_endpoints(t *testing.T) {
 	}
 
 	debugRoutes := map[string][]string{
-		"/eth/v1/debug/beacon/states/{state_id}": {http.MethodGet},
 		"/eth/v2/debug/beacon/states/{state_id}": {http.MethodGet},
 		"/eth/v2/debug/beacon/heads":             {http.MethodGet},
 		"/eth/v1/debug/fork_choice":              {http.MethodGet},
@@ -115,6 +115,7 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v1/beacon/states/{state_id}/validator_count":   {http.MethodGet},
 		"/prysm/v1/beacon/states/{state_id}/validator_count": {http.MethodGet},
 		"/prysm/v1/beacon/chain_head":                        {http.MethodGet},
+		"/prysm/v1/beacon/blobs":                             {http.MethodPost},
 	}
 
 	prysmNodeRoutes := map[string][]string{
@@ -133,22 +134,18 @@ func Test_endpoints(t *testing.T) {
 
 	s := &Service{cfg: &Config{}}
 
-	routesMap := combineMaps(beaconRoutes, builderRoutes, configRoutes, debugRoutes, eventsRoutes, nodeRoutes, validatorRoutes, rewardsRoutes, lightClientRoutes, blobRoutes, prysmValidatorRoutes, prysmNodeRoutes, prysmBeaconRoutes)
-	actual := s.endpoints(true, nil, nil, nil, nil, nil, nil)
-	for _, e := range actual {
-		methods, ok := routesMap[e.template]
-		assert.Equal(t, true, ok, "endpoint "+e.template+" not found")
-		if ok {
-			for _, em := range e.methods {
-				methodFound := false
-				for _, m := range methods {
-					if m == em {
-						methodFound = true
-						break
-					}
-				}
-				assert.Equal(t, true, methodFound, "method "+em+" for endpoint "+e.template+" not found")
-			}
+	endpoints := s.endpoints(true, nil, nil, nil, nil, nil, nil)
+	actualRoutes := make(map[string][]string, len(endpoints))
+	for _, e := range endpoints {
+		if _, ok := actualRoutes[e.template]; ok {
+			actualRoutes[e.template] = append(actualRoutes[e.template], e.methods...)
+		} else {
+			actualRoutes[e.template] = e.methods
 		}
 	}
+	expectedRoutes := combineMaps(beaconRoutes, builderRoutes, configRoutes, debugRoutes, eventsRoutes, nodeRoutes, validatorRoutes, rewardsRoutes, lightClientRoutes, blobRoutes, prysmValidatorRoutes, prysmNodeRoutes, prysmBeaconRoutes)
+
+	assert.Equal(t, true, maps.EqualFunc(expectedRoutes, actualRoutes, func(actualMethods []string, expectedMethods []string) bool {
+		return slices.Equal(expectedMethods, actualMethods)
+	}))
 }

beacon-chain/rpc/eth/beacon/handlers.go

@@ -1512,10 +1512,6 @@ func (s *Server) GetDepositSnapshot(w http.ResponseWriter, r *http.Request) {
 	ctx, span := trace.StartSpan(r.Context(), "beacon.GetDepositSnapshot")
 	defer span.End()
 
-	if s.BeaconDB == nil {
-		httputil.HandleError(w, "Could not retrieve beaconDB", http.StatusInternalServerError)
-		return
-	}
 	eth1data, err := s.BeaconDB.ExecutionChainData(ctx)
 	if err != nil {
 		httputil.HandleError(w, "Could not retrieve execution chain data: "+err.Error(), http.StatusInternalServerError)
@@ -1527,7 +1523,7 @@ func (s *Server) GetDepositSnapshot(w http.ResponseWriter, r *http.Request) {
 	}
 	snapshot := eth1data.DepositSnapshot
 	if snapshot == nil || len(snapshot.Finalized) == 0 {
-		httputil.HandleError(w, "No Finalized Snapshot Available", http.StatusNotFound)
+		httputil.HandleError(w, "No finalized snapshot available", http.StatusNotFound)
 		return
 	}
 	if len(snapshot.Finalized) > depositsnapshot.DepositContractDepth {

beacon-chain/rpc/eth/beacon/handlers_test.go

@@ -268,6 +268,38 @@ func TestGetBlockV2(t *testing.T) {
 		require.NoError(t, err)
 		assert.DeepEqual(t, blk, b)
 	})
+	t.Run("electra", func(t *testing.T) {
+		b := util.NewBeaconBlockElectra()
+		b.Block.Slot = 123
+		sb, err := blocks.NewSignedBeaconBlock(b)
+		require.NoError(t, err)
+		mockBlockFetcher := &testutil.MockBlocker{BlockToReturn: sb}
+		mockChainService := &chainMock.ChainService{
+			FinalizedRoots: map[[32]byte]bool{},
+		}
+		s := &Server{
+			OptimisticModeFetcher: mockChainService,
+			FinalizationFetcher:   mockChainService,
+			Blocker:               mockBlockFetcher,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example/eth/v2/beacon/blocks/{block_id}", nil)
+		request.SetPathValue("block_id", "head")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetBlockV2(writer, request)
+		require.Equal(t, http.StatusOK, writer.Code)
+		resp := &structs.GetBlockV2Response{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		assert.Equal(t, version.String(version.Electra), resp.Version)
+		sbb := &structs.SignedBeaconBlockElectra{Message: &structs.BeaconBlockElectra{}}
+		require.NoError(t, json.Unmarshal(resp.Data.Message, sbb.Message))
+		sbb.Signature = resp.Data.Signature
+		blk, err := sbb.ToConsensus()
+		require.NoError(t, err)
+		assert.DeepEqual(t, blk, b)
+	})
 	t.Run("execution optimistic", func(t *testing.T) {
 		b := util.NewBeaconBlockBellatrix()
 		sb, err := blocks.NewSignedBeaconBlock(b)
@@ -461,7 +493,29 @@ func TestGetBlockSSZV2(t *testing.T) {
 		require.NoError(t, err)
 		assert.DeepEqual(t, sszExpected, writer.Body.Bytes())
 	})
+	t.Run("electra", func(t *testing.T) {
+		b := util.NewBeaconBlockElectra()
+		b.Block.Slot = 123
+		sb, err := blocks.NewSignedBeaconBlock(b)
+		require.NoError(t, err)
 
+		s := &Server{
+			Blocker: &testutil.MockBlocker{BlockToReturn: sb},
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example/eth/v2/beacon/blocks/{block_id}", nil)
+		request.SetPathValue("block_id", "head")
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetBlockV2(writer, request)
+		require.Equal(t, http.StatusOK, writer.Code)
+		assert.Equal(t, version.String(version.Electra), writer.Header().Get(api.VersionHeader))
+		sszExpected, err := b.MarshalSSZ()
+		require.NoError(t, err)
+		assert.DeepEqual(t, sszExpected, writer.Body.Bytes())
+	})
 }
 
 func TestGetBlockAttestations(t *testing.T) {
@@ -759,6 +813,35 @@ func TestGetBlindedBlock(t *testing.T) {
 		require.NoError(t, err)
 		assert.DeepEqual(t, blk, b)
 	})
+	t.Run("electra", func(t *testing.T) {
+		b := util.NewBlindedBeaconBlockElectra()
+		sb, err := blocks.NewSignedBeaconBlock(b)
+		require.NoError(t, err)
+
+		mockChainService := &chainMock.ChainService{}
+		s := &Server{
+			OptimisticModeFetcher: mockChainService,
+			FinalizationFetcher:   mockChainService,
+			Blocker:               &testutil.MockBlocker{BlockToReturn: sb},
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example/eth/v1/beacon/blinded_blocks/{block_id}", nil)
+		request.SetPathValue("block_id", "head")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetBlindedBlock(writer, request)
+		require.Equal(t, http.StatusOK, writer.Code)
+		resp := &structs.GetBlockV2Response{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		assert.Equal(t, version.String(version.Electra), resp.Version)
+		sbb := &structs.SignedBlindedBeaconBlockElectra{Message: &structs.BlindedBeaconBlockElectra{}}
+		require.NoError(t, json.Unmarshal(resp.Data.Message, sbb.Message))
+		sbb.Signature = resp.Data.Signature
+		blk, err := sbb.ToConsensus()
+		require.NoError(t, err)
+		assert.DeepEqual(t, blk, b)
+	})
 	t.Run("execution optimistic", func(t *testing.T) {
 		b := util.NewBlindedBeaconBlockBellatrix()
 		sb, err := blocks.NewSignedBeaconBlock(b)

beacon-chain/rpc/eth/events/BUILD.bazel

@@ -20,6 +20,7 @@ go_library(
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/primitives:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
@@ -29,12 +30,16 @@ go_library(
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["events_test.go"],
+    srcs = [
+        "events_test.go",
+        "http_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
         "//beacon-chain/blockchain/testing:go_default_library",
@@ -49,9 +54,9 @@ go_test(
         "//consensus-types/primitives:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
-        "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_r3labs_sse_v2//:go_default_library",
     ],
 )

beacon-chain/rpc/eth/events/events.go

@@ -1,24 +1,26 @@
 package events
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
-	time2 "time"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/api"
 	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/operation"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
+	chaintime "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	"github.com/prysmaticlabs/prysm/v5/network/httputil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
@@ -26,9 +28,13 @@ import (
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	log "github.com/sirupsen/logrus"
 )
 
+const DefaultEventFeedDepth = 1000
+
 const (
+	InvalidTopic = "__invalid__"
 	// HeadTopic represents a new chain head event topic.
 	HeadTopic = "head"
 	// BlockTopic represents a new produced block event topic.
@@ -59,25 +65,83 @@ const (
 	LightClientOptimisticUpdateTopic = "light_client_optimistic_update"
 )
 
-const topicDataMismatch = "Event data type %T does not correspond to event topic %s"
+var (
+	errInvalidTopicName   = errors.New("invalid topic name")
+	errNoValidTopics      = errors.New("no valid topics specified")
+	errSlowReader         = errors.New("client failed to read fast enough to keep outgoing buffer below threshold")
+	errNotRequested       = errors.New("event not requested by client")
+	errUnhandledEventData = errors.New("unable to represent event data in the event stream")
+)
 
-const chanBuffer = 1000
+// StreamingResponseWriter defines a type that can be used by the eventStreamer.
+// This must be an http.ResponseWriter that supports flushing and hijacking.
+type StreamingResponseWriter interface {
+	http.ResponseWriter
+	http.Flusher
+}
 
-var casesHandled = map[string]bool{
-	HeadTopic:                        true,
-	BlockTopic:                       true,
-	AttestationTopic:                 true,
-	VoluntaryExitTopic:               true,
-	FinalizedCheckpointTopic:         true,
-	ChainReorgTopic:                  true,
-	SyncCommitteeContributionTopic:   true,
-	BLSToExecutionChangeTopic:        true,
-	PayloadAttributesTopic:           true,
-	BlobSidecarTopic:                 true,
-	ProposerSlashingTopic:            true,
-	AttesterSlashingTopic:            true,
-	LightClientFinalityUpdateTopic:   true,
-	LightClientOptimisticUpdateTopic: true,
+// The eventStreamer uses lazyReaders to defer serialization until the moment the value is ready to be written to the client.
+type lazyReader func() io.Reader
+
+var opsFeedEventTopics = map[feed.EventType]string{
+	operation.AggregatedAttReceived:             AttestationTopic,
+	operation.UnaggregatedAttReceived:           AttestationTopic,
+	operation.ExitReceived:                      VoluntaryExitTopic,
+	operation.SyncCommitteeContributionReceived: SyncCommitteeContributionTopic,
+	operation.BLSToExecutionChangeReceived:      BLSToExecutionChangeTopic,
+	operation.BlobSidecarReceived:               BlobSidecarTopic,
+	operation.AttesterSlashingReceived:          AttesterSlashingTopic,
+	operation.ProposerSlashingReceived:          ProposerSlashingTopic,
+}
+
+var stateFeedEventTopics = map[feed.EventType]string{
+	statefeed.NewHead:                     HeadTopic,
+	statefeed.MissedSlot:                  PayloadAttributesTopic,
+	statefeed.FinalizedCheckpoint:         FinalizedCheckpointTopic,
+	statefeed.LightClientFinalityUpdate:   LightClientFinalityUpdateTopic,
+	statefeed.LightClientOptimisticUpdate: LightClientOptimisticUpdateTopic,
+	statefeed.Reorg:                       ChainReorgTopic,
+	statefeed.BlockProcessed:              BlockTopic,
+}
+
+var topicsForStateFeed = topicsForFeed(stateFeedEventTopics)
+var topicsForOpsFeed = topicsForFeed(opsFeedEventTopics)
+
+func topicsForFeed(em map[feed.EventType]string) map[string]bool {
+	topics := make(map[string]bool, len(em))
+	for _, topic := range em {
+		topics[topic] = true
+	}
+	return topics
+}
+
+type topicRequest struct {
+	topics        map[string]bool
+	needStateFeed bool
+	needOpsFeed   bool
+}
+
+func (req *topicRequest) requested(topic string) bool {
+	return req.topics[topic]
+}
+
+func newTopicRequest(topics []string) (*topicRequest, error) {
+	req := &topicRequest{topics: make(map[string]bool)}
+	for _, name := range topics {
+		if topicsForStateFeed[name] {
+			req.needStateFeed = true
+		} else if topicsForOpsFeed[name] {
+			req.needOpsFeed = true
+		} else {
+			return nil, errors.Wrapf(errInvalidTopicName, name)
+		}
+		req.topics[name] = true
+	}
+	if len(req.topics) == 0 || (!req.needStateFeed && !req.needOpsFeed) {
+		return nil, errNoValidTopics
+	}
+
+	return req, nil
 }
 
 // StreamEvents provides an endpoint to subscribe to the beacon node Server-Sent-Events stream.
@@ -88,326 +152,412 @@ func (s *Server) StreamEvents(w http.ResponseWriter, r *http.Request) {
 	ctx, span := trace.StartSpan(r.Context(), "events.StreamEvents")
 	defer span.End()
 
-	flusher, ok := w.(http.Flusher)
+	topics, err := newTopicRequest(r.URL.Query()["topics"])
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	sw, ok := w.(StreamingResponseWriter)
 	if !ok {
-		httputil.HandleError(w, "Streaming unsupported!", http.StatusInternalServerError)
+		msg := "beacon node misconfiguration: http stack may not support required response handling features, like flushing"
+		httputil.HandleError(w, msg, http.StatusInternalServerError)
 		return
 	}
-
-	topics := r.URL.Query()["topics"]
-	if len(topics) == 0 {
-		httputil.HandleError(w, "No topics specified to subscribe to", http.StatusBadRequest)
-		return
+	depth := s.EventFeedDepth
+	if depth == 0 {
+		depth = DefaultEventFeedDepth
 	}
-	topicsMap := make(map[string]bool)
-	for _, topic := range topics {
-		if _, ok := casesHandled[topic]; !ok {
-			httputil.HandleError(w, fmt.Sprintf("Invalid topic: %s", topic), http.StatusBadRequest)
-			return
-		}
-		topicsMap[topic] = true
-	}
-
-	// Subscribe to event feeds from information received in the beacon node runtime.
-	opsChan := make(chan *feed.Event, chanBuffer)
-	opsSub := s.OperationNotifier.OperationFeed().Subscribe(opsChan)
-	stateChan := make(chan *feed.Event, chanBuffer)
-	stateSub := s.StateNotifier.StateFeed().Subscribe(stateChan)
-	defer opsSub.Unsubscribe()
-	defer stateSub.Unsubscribe()
-
-	// Set up SSE response headers
-	w.Header().Set("Content-Type", api.EventStreamMediaType)
-	w.Header().Set("Connection", api.KeepAlive)
-
-	// Handle each event received and context cancellation.
-	// We send a keepalive dummy message immediately to prevent clients
-	// stalling while waiting for the first response chunk.
-	// After that we send a keepalive dummy message every SECONDS_PER_SLOT
-	// to prevent anyone (e.g. proxy servers) from closing connections.
-	if err := sendKeepalive(w, flusher); err != nil {
+	es, err := newEventStreamer(depth, s.KeepAliveInterval)
+	if err != nil {
 		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	keepaliveTicker := time2.NewTicker(time2.Duration(params.BeaconConfig().SecondsPerSlot) * time2.Second)
 
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	api.SetSSEHeaders(sw)
+	go es.outboxWriteLoop(ctx, cancel, sw)
+	if err := es.recvEventLoop(ctx, cancel, topics, s); err != nil {
+		log.WithError(err).Debug("Shutting down StreamEvents handler.")
+	}
+}
+
+func newEventStreamer(buffSize int, ka time.Duration) (*eventStreamer, error) {
+	if ka == 0 {
+		ka = time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
+	}
+	return &eventStreamer{
+		outbox:    make(chan lazyReader, buffSize),
+		keepAlive: ka,
+	}, nil
+}
+
+type eventStreamer struct {
+	outbox    chan lazyReader
+	keepAlive time.Duration
+}
+
+func (es *eventStreamer) recvEventLoop(ctx context.Context, cancel context.CancelFunc, req *topicRequest, s *Server) error {
+	eventsChan := make(chan *feed.Event, len(es.outbox))
+	if req.needOpsFeed {
+		opsSub := s.OperationNotifier.OperationFeed().Subscribe(eventsChan)
+		defer opsSub.Unsubscribe()
+	}
+	if req.needStateFeed {
+		stateSub := s.StateNotifier.StateFeed().Subscribe(eventsChan)
+		defer stateSub.Unsubscribe()
+	}
 	for {
 		select {
-		case event := <-opsChan:
-			if err := handleBlockOperationEvents(w, flusher, topicsMap, event); err != nil {
-				httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
-				return
-			}
-		case event := <-stateChan:
-			if err := s.handleStateEvents(ctx, w, flusher, topicsMap, event); err != nil {
-				httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
-				return
-			}
-		case <-keepaliveTicker.C:
-			if err := sendKeepalive(w, flusher); err != nil {
-				httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
-				return
-			}
 		case <-ctx.Done():
+			return ctx.Err()
+		case event := <-eventsChan:
+			lr, err := s.lazyReaderForEvent(ctx, event, req)
+			if err != nil {
+				if !errors.Is(err, errNotRequested) {
+					log.WithField("event_type", fmt.Sprintf("%v", event.Data)).WithError(err).Error("StreamEvents API endpoint received an event it was unable to handle.")
+				}
+				continue
+			}
+			// If the client can't keep up, the outbox will eventually completely fill, at which
+			// safeWrite will error, and we'll hit the below return statement, at which point the deferred
+			// Unsuscribe calls will be made and the event feed will stop writing to this channel.
+			// Since the outbox and event stream channels are separately buffered, the event subscription
+			// channel should stay relatively empty, which gives this loop time to unsubscribe
+			// and cleanup before the event stream channel fills and disrupts other readers.
+			if err := es.safeWrite(ctx, lr); err != nil {
+				cancel()
+				// note: we could hijack the connection and close it here. Does that cause issues? What are the benefits?
+				// A benefit of hijack and close is that it may force an error on the remote end, however just closing the context of the
+				// http handler may be sufficient to cause the remote http response reader to close.
+				if errors.Is(err, errSlowReader) {
+					log.WithError(err).Warn("Client is unable to keep up with event stream, shutting down.")
+				}
+				return err
+			}
+		}
+	}
+}
+
+func (es *eventStreamer) safeWrite(ctx context.Context, rf func() io.Reader) error {
+	if rf == nil {
+		return nil
+	}
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case es.outbox <- rf:
+		return nil
+	default:
+		// If this is the case, the select case to write to the outbox could not proceed, meaning the outbox is full.
+		// If a reader can't keep up with the stream, we shut them down.
+		return errSlowReader
+	}
+}
+
+// newlineReader is used to write keep-alives to the client.
+// keep-alives in the sse protocol are a single ':' colon followed by 2 newlines.
+func newlineReader() io.Reader {
+	return bytes.NewBufferString(":\n\n")
+}
+
+// outboxWriteLoop runs in a separate goroutine. Its job is to write the values in the outbox to
+// the client as fast as the client can read them.
+func (es *eventStreamer) outboxWriteLoop(ctx context.Context, cancel context.CancelFunc, w StreamingResponseWriter) {
+	var err error
+	defer func() {
+		if err != nil {
+			log.WithError(err).Debug("Event streamer shutting down due to error.")
+		}
+	}()
+	defer cancel()
+	// Write a keepalive at the start to test the connection and simplify test setup.
+	if err = es.writeOutbox(ctx, w, nil); err != nil {
+		return
+	}
+
+	kaT := time.NewTimer(es.keepAlive)
+	// Ensure the keepalive timer is stopped and drained if it has fired.
+	defer func() {
+		if !kaT.Stop() {
+			<-kaT.C
+		}
+	}()
+	for {
+		select {
+		case <-ctx.Done():
+			err = ctx.Err()
 			return
+		case <-kaT.C:
+			if err = es.writeOutbox(ctx, w, nil); err != nil {
+				return
+			}
+			// In this case the timer doesn't need to be Stopped before the Reset call after the select statement,
+			// because the timer has already fired.
+		case lr := <-es.outbox:
+			if err = es.writeOutbox(ctx, w, lr); err != nil {
+				return
+			}
+			// We don't know if the timer fired concurrently to this case being ready, so we need to check the return
+			// of Stop and drain the timer channel if it fired. We won't need to do this in go 1.23.
+			if !kaT.Stop() {
+				<-kaT.C
+			}
+		}
+		kaT.Reset(es.keepAlive)
+	}
+}
+
+func (es *eventStreamer) writeOutbox(ctx context.Context, w StreamingResponseWriter, first lazyReader) error {
+	needKeepAlive := true
+	if first != nil {
+		if _, err := io.Copy(w, first()); err != nil {
+			return err
+		}
+		needKeepAlive = false
+	}
+	// While the first event was being read by the client, further events may be queued in the outbox.
+	// We can drain them right away rather than go back out to the outer select statement, where the keepAlive timer
+	// may have fired, triggering an unnecessary extra keep-alive write and flush.
+	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case rf := <-es.outbox:
+			if _, err := io.Copy(w, rf()); err != nil {
+				return err
+			}
+			needKeepAlive = false
+		default:
+			if needKeepAlive {
+				if _, err := io.Copy(w, newlineReader()); err != nil {
+					return err
+				}
+			}
+			w.Flush()
+			return nil
 		}
 	}
 }
 
-func handleBlockOperationEvents(w http.ResponseWriter, flusher http.Flusher, requestedTopics map[string]bool, event *feed.Event) error {
-	switch event.Type {
-	case operation.AggregatedAttReceived:
-		if _, ok := requestedTopics[AttestationTopic]; !ok {
-			return nil
-		}
-		attData, ok := event.Data.(*operation.AggregatedAttReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, AttestationTopic)
-		}
-		att := structs.AttFromConsensus(attData.Attestation.Aggregate)
-		return send(w, flusher, AttestationTopic, att)
-	case operation.UnaggregatedAttReceived:
-		if _, ok := requestedTopics[AttestationTopic]; !ok {
-			return nil
-		}
-		attData, ok := event.Data.(*operation.UnAggregatedAttReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, AttestationTopic)
-		}
-		a, ok := attData.Attestation.(*eth.Attestation)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, AttestationTopic)
-		}
-		att := structs.AttFromConsensus(a)
-		return send(w, flusher, AttestationTopic, att)
-	case operation.ExitReceived:
-		if _, ok := requestedTopics[VoluntaryExitTopic]; !ok {
-			return nil
-		}
-		exitData, ok := event.Data.(*operation.ExitReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, VoluntaryExitTopic)
-		}
-		exit := structs.SignedExitFromConsensus(exitData.Exit)
-		return send(w, flusher, VoluntaryExitTopic, exit)
-	case operation.SyncCommitteeContributionReceived:
-		if _, ok := requestedTopics[SyncCommitteeContributionTopic]; !ok {
-			return nil
-		}
-		contributionData, ok := event.Data.(*operation.SyncCommitteeContributionReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, SyncCommitteeContributionTopic)
-		}
-		contribution := structs.SignedContributionAndProofFromConsensus(contributionData.Contribution)
-		return send(w, flusher, SyncCommitteeContributionTopic, contribution)
-	case operation.BLSToExecutionChangeReceived:
-		if _, ok := requestedTopics[BLSToExecutionChangeTopic]; !ok {
-			return nil
-		}
-		changeData, ok := event.Data.(*operation.BLSToExecutionChangeReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, BLSToExecutionChangeTopic)
-		}
-		return send(w, flusher, BLSToExecutionChangeTopic, structs.SignedBLSChangeFromConsensus(changeData.Change))
-	case operation.BlobSidecarReceived:
-		if _, ok := requestedTopics[BlobSidecarTopic]; !ok {
-			return nil
-		}
-		blobData, ok := event.Data.(*operation.BlobSidecarReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, BlobSidecarTopic)
-		}
-		versionedHash := blockchain.ConvertKzgCommitmentToVersionedHash(blobData.Blob.KzgCommitment)
-		blobEvent := &structs.BlobSidecarEvent{
-			BlockRoot:     hexutil.Encode(blobData.Blob.BlockRootSlice()),
-			Index:         fmt.Sprintf("%d", blobData.Blob.Index),
-			Slot:          fmt.Sprintf("%d", blobData.Blob.Slot()),
-			VersionedHash: versionedHash.String(),
-			KzgCommitment: hexutil.Encode(blobData.Blob.KzgCommitment),
-		}
-		return send(w, flusher, BlobSidecarTopic, blobEvent)
-	case operation.AttesterSlashingReceived:
-		if _, ok := requestedTopics[AttesterSlashingTopic]; !ok {
-			return nil
-		}
-		attesterSlashingData, ok := event.Data.(*operation.AttesterSlashingReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, AttesterSlashingTopic)
-		}
-		slashing, ok := attesterSlashingData.AttesterSlashing.(*eth.AttesterSlashing)
-		if ok {
-			return send(w, flusher, AttesterSlashingTopic, structs.AttesterSlashingFromConsensus(slashing))
-		}
-		// TODO: extend to Electra
-	case operation.ProposerSlashingReceived:
-		if _, ok := requestedTopics[ProposerSlashingTopic]; !ok {
-			return nil
-		}
-		proposerSlashingData, ok := event.Data.(*operation.ProposerSlashingReceivedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, ProposerSlashingTopic)
-		}
-		return send(w, flusher, ProposerSlashingTopic, structs.ProposerSlashingFromConsensus(proposerSlashingData.ProposerSlashing))
+func jsonMarshalReader(name string, v any) io.Reader {
+	d, err := json.Marshal(v)
+	if err != nil {
+		log.WithError(err).WithField("type_name", fmt.Sprintf("%T", v)).Error("Could not marshal event data.")
+		return nil
 	}
-	return nil
+	return bytes.NewBufferString("event: " + name + "\ndata: " + string(d) + "\n\n")
 }
 
-func (s *Server) handleStateEvents(ctx context.Context, w http.ResponseWriter, flusher http.Flusher, requestedTopics map[string]bool, event *feed.Event) error {
-	switch event.Type {
-	case statefeed.NewHead:
-		if _, ok := requestedTopics[HeadTopic]; ok {
-			headData, ok := event.Data.(*ethpb.EventHead)
-			if !ok {
-				return write(w, flusher, topicDataMismatch, event.Data, HeadTopic)
-			}
-			head := &structs.HeadEvent{
-				Slot:                      fmt.Sprintf("%d", headData.Slot),
-				Block:                     hexutil.Encode(headData.Block),
-				State:                     hexutil.Encode(headData.State),
-				EpochTransition:           headData.EpochTransition,
-				ExecutionOptimistic:       headData.ExecutionOptimistic,
-				PreviousDutyDependentRoot: hexutil.Encode(headData.PreviousDutyDependentRoot),
-				CurrentDutyDependentRoot:  hexutil.Encode(headData.CurrentDutyDependentRoot),
-			}
-			return send(w, flusher, HeadTopic, head)
+func topicForEvent(event *feed.Event) string {
+	switch event.Data.(type) {
+	case *operation.AggregatedAttReceivedData:
+		return AttestationTopic
+	case *operation.UnAggregatedAttReceivedData:
+		return AttestationTopic
+	case *operation.ExitReceivedData:
+		return VoluntaryExitTopic
+	case *operation.SyncCommitteeContributionReceivedData:
+		return SyncCommitteeContributionTopic
+	case *operation.BLSToExecutionChangeReceivedData:
+		return BLSToExecutionChangeTopic
+	case *operation.BlobSidecarReceivedData:
+		return BlobSidecarTopic
+	case *operation.AttesterSlashingReceivedData:
+		return AttesterSlashingTopic
+	case *operation.ProposerSlashingReceivedData:
+		return ProposerSlashingTopic
+	case *ethpb.EventHead:
+		return HeadTopic
+	case *ethpb.EventFinalizedCheckpoint:
+		return FinalizedCheckpointTopic
+	case *ethpbv2.LightClientFinalityUpdateWithVersion:
+		return LightClientFinalityUpdateTopic
+	case *ethpbv2.LightClientOptimisticUpdateWithVersion:
+		return LightClientOptimisticUpdateTopic
+	case *ethpb.EventChainReorg:
+		return ChainReorgTopic
+	case *statefeed.BlockProcessedData:
+		return BlockTopic
+	default:
+		if event.Type == statefeed.MissedSlot {
+			return PayloadAttributesTopic
 		}
-		if _, ok := requestedTopics[PayloadAttributesTopic]; ok {
-			return s.sendPayloadAttributes(ctx, w, flusher)
-		}
-	case statefeed.MissedSlot:
-		if _, ok := requestedTopics[PayloadAttributesTopic]; ok {
-			return s.sendPayloadAttributes(ctx, w, flusher)
-		}
-	case statefeed.FinalizedCheckpoint:
-		if _, ok := requestedTopics[FinalizedCheckpointTopic]; !ok {
-			return nil
-		}
-		checkpointData, ok := event.Data.(*ethpb.EventFinalizedCheckpoint)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, FinalizedCheckpointTopic)
-		}
-		checkpoint := &structs.FinalizedCheckpointEvent{
-			Block:               hexutil.Encode(checkpointData.Block),
-			State:               hexutil.Encode(checkpointData.State),
-			Epoch:               fmt.Sprintf("%d", checkpointData.Epoch),
-			ExecutionOptimistic: checkpointData.ExecutionOptimistic,
-		}
-		return send(w, flusher, FinalizedCheckpointTopic, checkpoint)
-	case statefeed.LightClientFinalityUpdate:
-		if _, ok := requestedTopics[LightClientFinalityUpdateTopic]; !ok {
-			return nil
-		}
-		updateData, ok := event.Data.(*ethpbv2.LightClientFinalityUpdateWithVersion)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, LightClientFinalityUpdateTopic)
-		}
-		update, err := structs.LightClientFinalityUpdateFromConsensus(updateData.Data)
-		if err != nil {
-			return err
-		}
-		updateEvent := &structs.LightClientFinalityUpdateEvent{
-			Version: version.String(int(updateData.Version)),
-			Data:    update,
-		}
-		return send(w, flusher, LightClientFinalityUpdateTopic, updateEvent)
-	case statefeed.LightClientOptimisticUpdate:
-		if _, ok := requestedTopics[LightClientOptimisticUpdateTopic]; !ok {
-			return nil
-		}
-		updateData, ok := event.Data.(*ethpbv2.LightClientOptimisticUpdateWithVersion)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, LightClientOptimisticUpdateTopic)
-		}
-		update, err := structs.LightClientOptimisticUpdateFromConsensus(updateData.Data)
-		if err != nil {
-			return err
-		}
-		updateEvent := &structs.LightClientOptimisticUpdateEvent{
-			Version: version.String(int(updateData.Version)),
-			Data:    update,
-		}
-		return send(w, flusher, LightClientOptimisticUpdateTopic, updateEvent)
-	case statefeed.Reorg:
-		if _, ok := requestedTopics[ChainReorgTopic]; !ok {
-			return nil
-		}
-		reorgData, ok := event.Data.(*ethpb.EventChainReorg)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, ChainReorgTopic)
-		}
-		reorg := &structs.ChainReorgEvent{
-			Slot:                fmt.Sprintf("%d", reorgData.Slot),
-			Depth:               fmt.Sprintf("%d", reorgData.Depth),
-			OldHeadBlock:        hexutil.Encode(reorgData.OldHeadBlock),
-			NewHeadBlock:        hexutil.Encode(reorgData.NewHeadBlock),
-			OldHeadState:        hexutil.Encode(reorgData.OldHeadState),
-			NewHeadState:        hexutil.Encode(reorgData.NewHeadState),
-			Epoch:               fmt.Sprintf("%d", reorgData.Epoch),
-			ExecutionOptimistic: reorgData.ExecutionOptimistic,
-		}
-		return send(w, flusher, ChainReorgTopic, reorg)
-	case statefeed.BlockProcessed:
-		if _, ok := requestedTopics[BlockTopic]; !ok {
-			return nil
-		}
-		blkData, ok := event.Data.(*statefeed.BlockProcessedData)
-		if !ok {
-			return write(w, flusher, topicDataMismatch, event.Data, BlockTopic)
-		}
-		blockRoot, err := blkData.SignedBlock.Block().HashTreeRoot()
-		if err != nil {
-			return write(w, flusher, "Could not get block root: "+err.Error())
-		}
-		blk := &structs.BlockEvent{
-			Slot:                fmt.Sprintf("%d", blkData.Slot),
-			Block:               hexutil.Encode(blockRoot[:]),
-			ExecutionOptimistic: blkData.Optimistic,
-		}
-		return send(w, flusher, BlockTopic, blk)
+		return InvalidTopic
+	}
+}
+
+func (s *Server) lazyReaderForEvent(ctx context.Context, event *feed.Event, topics *topicRequest) (lazyReader, error) {
+	eventName := topicForEvent(event)
+	if !topics.requested(eventName) {
+		return nil, errNotRequested
+	}
+	if eventName == PayloadAttributesTopic {
+		return s.currentPayloadAttributes(ctx)
+	}
+	if event == nil || event.Data == nil {
+		return nil, errors.New("event or event data is nil")
+	}
+	switch v := event.Data.(type) {
+	case *ethpb.EventHead:
+		// The head event is a special case because, if the client requested the payload attributes topic,
+		// we send two event messages in reaction; the head event and the payload attributes.
+		headReader := func() io.Reader {
+			return jsonMarshalReader(eventName, structs.HeadEventFromV1(v))
+		}
+		// Don't do the expensive attr lookup unless the client requested it.
+		if !topics.requested(PayloadAttributesTopic) {
+			return headReader, nil
+		}
+		// Since payload attributes could change before the outbox is written, we need to do a blocking operation to
+		// get the current payload attributes right here.
+		attrReader, err := s.currentPayloadAttributes(ctx)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get payload attributes for head event")
+		}
+		return func() io.Reader {
+			return io.MultiReader(headReader(), attrReader())
+		}, nil
+	case *operation.AggregatedAttReceivedData:
+		return func() io.Reader {
+			att := structs.AttFromConsensus(v.Attestation.Aggregate)
+			return jsonMarshalReader(eventName, att)
+		}, nil
+	case *operation.UnAggregatedAttReceivedData:
+		att, ok := v.Attestation.(*eth.Attestation)
+		if !ok {
+			return nil, errors.Wrapf(errUnhandledEventData, "Unexpected type %T for the .Attestation field of UnAggregatedAttReceivedData", v.Attestation)
+		}
+		return func() io.Reader {
+			att := structs.AttFromConsensus(att)
+			return jsonMarshalReader(eventName, att)
+		}, nil
+	case *operation.ExitReceivedData:
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.SignedExitFromConsensus(v.Exit))
+		}, nil
+	case *operation.SyncCommitteeContributionReceivedData:
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.SignedContributionAndProofFromConsensus(v.Contribution))
+		}, nil
+	case *operation.BLSToExecutionChangeReceivedData:
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.SignedBLSChangeFromConsensus(v.Change))
+		}, nil
+	case *operation.BlobSidecarReceivedData:
+		return func() io.Reader {
+			versionedHash := primitives.ConvertKzgCommitmentToVersionedHash(v.Blob.KzgCommitment)
+			return jsonMarshalReader(eventName, &structs.BlobSidecarEvent{
+				BlockRoot:     hexutil.Encode(v.Blob.BlockRootSlice()),
+				Index:         fmt.Sprintf("%d", v.Blob.Index),
+				Slot:          fmt.Sprintf("%d", v.Blob.Slot()),
+				VersionedHash: versionedHash.String(),
+				KzgCommitment: hexutil.Encode(v.Blob.KzgCommitment),
+			})
+		}, nil
+	case *operation.AttesterSlashingReceivedData:
+		slashing, ok := v.AttesterSlashing.(*eth.AttesterSlashing)
+		if !ok {
+			return nil, errors.Wrapf(errUnhandledEventData, "Unexpected type %T for the .AttesterSlashing field of AttesterSlashingReceivedData", v.AttesterSlashing)
+		}
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.AttesterSlashingFromConsensus(slashing))
+		}, nil
+	case *operation.ProposerSlashingReceivedData:
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.ProposerSlashingFromConsensus(v.ProposerSlashing))
+		}, nil
+	case *ethpb.EventFinalizedCheckpoint:
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.FinalizedCheckpointEventFromV1(v))
+		}, nil
+	case *ethpbv2.LightClientFinalityUpdateWithVersion:
+		cv, err := structs.LightClientFinalityUpdateFromConsensus(v.Data)
+		if err != nil {
+			return nil, errors.Wrap(err, "LightClientFinalityUpdateWithVersion event conversion failure")
+		}
+		ev := &structs.LightClientFinalityUpdateEvent{
+			Version: version.String(int(v.Version)),
+			Data:    cv,
+		}
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, ev)
+		}, nil
+	case *ethpbv2.LightClientOptimisticUpdateWithVersion:
+		cv, err := structs.LightClientOptimisticUpdateFromConsensus(v.Data)
+		if err != nil {
+			return nil, errors.Wrap(err, "LightClientOptimisticUpdateWithVersion event conversion failure")
+		}
+		ev := &structs.LightClientOptimisticUpdateEvent{
+			Version: version.String(int(v.Version)),
+			Data:    cv,
+		}
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, ev)
+		}, nil
+	case *ethpb.EventChainReorg:
+		return func() io.Reader {
+			return jsonMarshalReader(eventName, structs.EventChainReorgFromV1(v))
+		}, nil
+	case *statefeed.BlockProcessedData:
+		blockRoot, err := v.SignedBlock.Block().HashTreeRoot()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not compute block root for BlockProcessedData state feed event")
+		}
+		return func() io.Reader {
+			blk := &structs.BlockEvent{
+				Slot:                fmt.Sprintf("%d", v.Slot),
+				Block:               hexutil.Encode(blockRoot[:]),
+				ExecutionOptimistic: v.Optimistic,
+			}
+			return jsonMarshalReader(eventName, blk)
+		}, nil
+	default:
+		return nil, errors.Wrapf(errUnhandledEventData, "event data type %T unsupported", v)
 	}
-	return nil
 }
 
 // This event stream is intended to be used by builders and relays.
 // Parent fields are based on state at N_{current_slot}, while the rest of fields are based on state of N_{current_slot + 1}
-func (s *Server) sendPayloadAttributes(ctx context.Context, w http.ResponseWriter, flusher http.Flusher) error {
+func (s *Server) currentPayloadAttributes(ctx context.Context) (lazyReader, error) {
 	headRoot, err := s.HeadFetcher.HeadRoot(ctx)
 	if err != nil {
-		return write(w, flusher, "Could not get head root: "+err.Error())
+		return nil, errors.Wrap(err, "could not get head root")
 	}
 	st, err := s.HeadFetcher.HeadState(ctx)
 	if err != nil {
-		return write(w, flusher, "Could not get head state: "+err.Error())
+		return nil, errors.Wrap(err, "could not get head state")
 	}
 	// advance the head state
 	headState, err := transition.ProcessSlotsIfPossible(ctx, st, s.ChainInfoFetcher.CurrentSlot()+1)
 	if err != nil {
-		return write(w, flusher, "Could not advance head state: "+err.Error())
+		return nil, errors.Wrap(err, "could not advance head state")
 	}
 
 	headBlock, err := s.HeadFetcher.HeadBlock(ctx)
 	if err != nil {
-		return write(w, flusher, "Could not get head block: "+err.Error())
+		return nil, errors.Wrap(err, "could not get head block")
 	}
 
 	headPayload, err := headBlock.Block().Body().Execution()
 	if err != nil {
-		return write(w, flusher, "Could not get execution payload: "+err.Error())
+		return nil, errors.Wrap(err, "could not get execution payload")
 	}
 
 	t, err := slots.ToTime(headState.GenesisTime(), headState.Slot())
 	if err != nil {
-		return write(w, flusher, "Could not get head state slot time: "+err.Error())
+		return nil, errors.Wrap(err, "could not get head state slot time")
 	}
 
-	prevRando, err := helpers.RandaoMix(headState, time.CurrentEpoch(headState))
+	prevRando, err := helpers.RandaoMix(headState, chaintime.CurrentEpoch(headState))
 	if err != nil {
-		return write(w, flusher, "Could not get head state randao mix: "+err.Error())
+		return nil, errors.Wrap(err, "could not get head state randao mix")
 	}
 
 	proposerIndex, err := helpers.BeaconProposerIndex(ctx, headState)
 	if err != nil {
-		return write(w, flusher, "Could not get head state proposer index: "+err.Error())
+		return nil, errors.Wrap(err, "could not get head state proposer index")
 	}
 	feeRecipient := params.BeaconConfig().DefaultFeeRecipient.Bytes()
 	tValidator, exists := s.TrackedValidatorsCache.Validator(proposerIndex)
@@ -425,7 +575,7 @@ func (s *Server) sendPayloadAttributes(ctx context.Context, w http.ResponseWrite
 	case version.Capella:
 		withdrawals, _, err := headState.ExpectedWithdrawals()
 		if err != nil {
-			return write(w, flusher, "Could not get head state expected withdrawals: "+err.Error())
+			return nil, errors.Wrap(err, "could not get head state expected withdrawals")
 		}
 		attributes = &structs.PayloadAttributesV2{
 			Timestamp:             fmt.Sprintf("%d", t.Unix()),
@@ -436,11 +586,11 @@ func (s *Server) sendPayloadAttributes(ctx context.Context, w http.ResponseWrite
 	case version.Deneb, version.Electra:
 		withdrawals, _, err := headState.ExpectedWithdrawals()
 		if err != nil {
-			return write(w, flusher, "Could not get head state expected withdrawals: "+err.Error())
+			return nil, errors.Wrap(err, "could not get head state expected withdrawals")
 		}
 		parentRoot, err := headBlock.Block().HashTreeRoot()
 		if err != nil {
-			return write(w, flusher, "Could not get head block root: "+err.Error())
+			return nil, errors.Wrap(err, "could not get head block root")
 		}
 		attributes = &structs.PayloadAttributesV3{
 			Timestamp:             fmt.Sprintf("%d", t.Unix()),
@@ -450,12 +600,12 @@ func (s *Server) sendPayloadAttributes(ctx context.Context, w http.ResponseWrite
 			ParentBeaconBlockRoot: hexutil.Encode(parentRoot[:]),
 		}
 	default:
-		return write(w, flusher, "Payload version %s is not supported", version.String(headState.Version()))
+		return nil, errors.Wrapf(err, "Payload version %s is not supported", version.String(headState.Version()))
 	}
 
 	attributesBytes, err := json.Marshal(attributes)
 	if err != nil {
-		return write(w, flusher, err.Error())
+		return nil, errors.Wrap(err, "errors marshaling payload attributes to json")
 	}
 	eventData := structs.PayloadAttributesEventData{
 		ProposerIndex:     fmt.Sprintf("%d", proposerIndex),
@@ -467,31 +617,12 @@ func (s *Server) sendPayloadAttributes(ctx context.Context, w http.ResponseWrite
 	}
 	eventDataBytes, err := json.Marshal(eventData)
 	if err != nil {
-		return write(w, flusher, err.Error())
+		return nil, errors.Wrap(err, "errors marshaling payload attributes event data to json")
 	}
-	return send(w, flusher, PayloadAttributesTopic, &structs.PayloadAttributesEvent{
-		Version: version.String(headState.Version()),
-		Data:    eventDataBytes,
-	})
-}
-
-func send(w http.ResponseWriter, flusher http.Flusher, name string, data interface{}) error {
-	j, err := json.Marshal(data)
-	if err != nil {
-		return write(w, flusher, "Could not marshal event to JSON: "+err.Error())
-	}
-	return write(w, flusher, "event: %s\ndata: %s\n\n", name, string(j))
-}
-
-func sendKeepalive(w http.ResponseWriter, flusher http.Flusher) error {
-	return write(w, flusher, ":\n\n")
-}
-
-func write(w http.ResponseWriter, flusher http.Flusher, format string, a ...any) error {
-	_, err := fmt.Fprintf(w, format, a...)
-	if err != nil {
-		return errors.Wrap(err, "could not write to response writer")
-	}
-	flusher.Flush()
-	return nil
+	return func() io.Reader {
+		return jsonMarshalReader(PayloadAttributesTopic, &structs.PayloadAttributesEvent{
+			Version: version.String(headState.Version()),
+			Data:    eventDataBytes,
+		})
+	}, nil
 }

beacon-chain/rpc/eth/events/events_test.go

@@ -1,6 +1,7 @@
 package events
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"math"
@@ -23,56 +24,99 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	sse "github.com/r3labs/sse/v2"
 )
 
-type flushableResponseRecorder struct {
-	*httptest.ResponseRecorder
-	flushed bool
+func requireAllEventsReceived(t *testing.T, stn, opn *mockChain.EventFeedWrapper, events []*feed.Event, req *topicRequest, s *Server, w *StreamingResponseWriterRecorder) {
+	// maxBufferSize param copied from sse lib client code
+	sseR := sse.NewEventStreamReader(w.Body(), 1<<24)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	expected := make(map[string]bool)
+	for i := range events {
+		ev := events[i]
+		// serialize the event the same way the server will so that we can compare expectation to results.
+		top := topicForEvent(ev)
+		eb, err := s.lazyReaderForEvent(context.Background(), ev, req)
+		require.NoError(t, err)
+		exb, err := io.ReadAll(eb())
+		require.NoError(t, err)
+		exs := string(exb[0 : len(exb)-2]) // remove trailing double newline
+
+		if topicsForOpsFeed[top] {
+			if err := opn.WaitForSubscription(ctx); err != nil {
+				t.Fatal(err)
+			}
+			// Send the event on the feed.
+			s.OperationNotifier.OperationFeed().Send(ev)
+		} else {
+			if err := stn.WaitForSubscription(ctx); err != nil {
+				t.Fatal(err)
+			}
+			// Send the event on the feed.
+			s.StateNotifier.StateFeed().Send(ev)
+		}
+		expected[exs] = true
+	}
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		for {
+			ev, err := sseR.ReadEvent()
+			if err == io.EOF {
+				return
+			}
+			require.NoError(t, err)
+			str := string(ev)
+			delete(expected, str)
+			if len(expected) == 0 {
+				return
+			}
+		}
+	}()
+	select {
+	case <-done:
+		break
+	case <-ctx.Done():
+		t.Fatalf("context canceled / timed out waiting for events, err=%v", ctx.Err())
+	}
+	require.Equal(t, 0, len(expected), "expected events not seen")
 }
 
-func (f *flushableResponseRecorder) Flush() {
-	f.flushed = true
+func (tr *topicRequest) testHttpRequest(_ *testing.T) *http.Request {
+	tq := make([]string, 0, len(tr.topics))
+	for topic := range tr.topics {
+		tq = append(tq, "topics="+topic)
+	}
+	return httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://example.com/eth/v1/events?%s", strings.Join(tq, "&")), nil)
 }
 
-func TestStreamEvents_OperationsEvents(t *testing.T) {
-	t.Run("operations", func(t *testing.T) {
-		s := &Server{
-			StateNotifier:     &mockChain.MockStateNotifier{},
-			OperationNotifier: &mockChain.MockOperationNotifier{},
-		}
+func operationEventsFixtures(t *testing.T) (*topicRequest, []*feed.Event) {
+	topics, err := newTopicRequest([]string{
+		AttestationTopic,
+		VoluntaryExitTopic,
+		SyncCommitteeContributionTopic,
+		BLSToExecutionChangeTopic,
+		BlobSidecarTopic,
+		AttesterSlashingTopic,
+		ProposerSlashingTopic,
+	})
+	require.NoError(t, err)
+	ro, err := blocks.NewROBlob(util.HydrateBlobSidecar(&eth.BlobSidecar{}))
+	require.NoError(t, err)
+	vblob := blocks.NewVerifiedROBlob(ro)
 
-		topics := []string{
-			AttestationTopic,
-			VoluntaryExitTopic,
-			SyncCommitteeContributionTopic,
-			BLSToExecutionChangeTopic,
-			BlobSidecarTopic,
-			AttesterSlashingTopic,
-			ProposerSlashingTopic,
-		}
-		for i, topic := range topics {
-			topics[i] = "topics=" + topic
-		}
-		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://example.com/eth/v1/events?%s", strings.Join(topics, "&")), nil)
-		w := &flushableResponseRecorder{
-			ResponseRecorder: httptest.NewRecorder(),
-		}
-
-		go func() {
-			s.StreamEvents(w, request)
-		}()
-		// wait for initiation of StreamEvents
-		time.Sleep(100 * time.Millisecond)
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+	return topics, []*feed.Event{
+		&feed.Event{
 			Type: operation.UnaggregatedAttReceived,
 			Data: &operation.UnAggregatedAttReceivedData{
 				Attestation: util.HydrateAttestation(&eth.Attestation{}),
 			},
-		})
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.AggregatedAttReceived,
 			Data: &operation.AggregatedAttReceivedData{
 				Attestation: &eth.AggregateAttestationAndProof{
@@ -81,8 +125,8 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					SelectionProof:  make([]byte, 96),
 				},
 			},
-		})
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.ExitReceived,
 			Data: &operation.ExitReceivedData{
 				Exit: &eth.SignedVoluntaryExit{
@@ -93,8 +137,8 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					Signature: make([]byte, 96),
 				},
 			},
-		})
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.SyncCommitteeContributionReceived,
 			Data: &operation.SyncCommitteeContributionReceivedData{
 				Contribution: &eth.SignedContributionAndProof{
@@ -112,8 +156,8 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					Signature: make([]byte, 96),
 				},
 			},
-		})
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.BLSToExecutionChangeReceived,
 			Data: &operation.BLSToExecutionChangeReceivedData{
 				Change: &eth.SignedBLSToExecutionChange{
@@ -125,18 +169,14 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					Signature: make([]byte, 96),
 				},
 			},
-		})
-		ro, err := blocks.NewROBlob(util.HydrateBlobSidecar(&eth.BlobSidecar{}))
-		require.NoError(t, err)
-		vblob := blocks.NewVerifiedROBlob(ro)
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.BlobSidecarReceived,
 			Data: &operation.BlobSidecarReceivedData{
 				Blob: &vblob,
 			},
-		})
-
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.AttesterSlashingReceived,
 			Data: &operation.AttesterSlashingReceivedData{
 				AttesterSlashing: &eth.AttesterSlashing{
@@ -168,9 +208,8 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					},
 				},
 			},
-		})
-
-		s.OperationNotifier.OperationFeed().Send(&feed.Event{
+		},
+		&feed.Event{
 			Type: operation.ProposerSlashingReceived,
 			Data: &operation.ProposerSlashingReceivedData{
 				ProposerSlashing: &eth.ProposerSlashing{
@@ -192,100 +231,107 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					},
 				},
 			},
-		})
+		},
+	}
+}
 
-		time.Sleep(1 * time.Second)
-		request.Context().Done()
+func TestStreamEvents_OperationsEvents(t *testing.T) {
+	t.Run("operations", func(t *testing.T) {
+		stn := mockChain.NewEventFeedWrapper()
+		opn := mockChain.NewEventFeedWrapper()
+		s := &Server{
+			StateNotifier:     &mockChain.SimpleNotifier{Feed: stn},
+			OperationNotifier: &mockChain.SimpleNotifier{Feed: opn},
+		}
 
-		resp := w.Result()
-		body, err := io.ReadAll(resp.Body)
-		require.NoError(t, err)
-		require.NotNil(t, body)
-		assert.Equal(t, operationsResult, string(body))
+		topics, events := operationEventsFixtures(t)
+		request := topics.testHttpRequest(t)
+		w := NewStreamingResponseWriterRecorder()
+
+		go func() {
+			s.StreamEvents(w, request)
+		}()
+
+		requireAllEventsReceived(t, stn, opn, events, topics, s, w)
 	})
 	t.Run("state", func(t *testing.T) {
+		stn := mockChain.NewEventFeedWrapper()
+		opn := mockChain.NewEventFeedWrapper()
 		s := &Server{
-			StateNotifier:     &mockChain.MockStateNotifier{},
-			OperationNotifier: &mockChain.MockOperationNotifier{},
+			StateNotifier:     &mockChain.SimpleNotifier{Feed: stn},
+			OperationNotifier: &mockChain.SimpleNotifier{Feed: opn},
 		}
 
-		topics := []string{HeadTopic, FinalizedCheckpointTopic, ChainReorgTopic, BlockTopic}
-		for i, topic := range topics {
-			topics[i] = "topics=" + topic
-		}
-		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://example.com/eth/v1/events?%s", strings.Join(topics, "&")), nil)
-		w := &flushableResponseRecorder{
-			ResponseRecorder: httptest.NewRecorder(),
+		topics, err := newTopicRequest([]string{
+			HeadTopic,
+			FinalizedCheckpointTopic,
+			ChainReorgTopic,
+			BlockTopic,
+		})
+		require.NoError(t, err)
+		request := topics.testHttpRequest(t)
+		w := NewStreamingResponseWriterRecorder()
+
+		b, err := blocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlock(&eth.SignedBeaconBlock{}))
+		require.NoError(t, err)
+		events := []*feed.Event{
+			&feed.Event{
+				Type: statefeed.BlockProcessed,
+				Data: &statefeed.BlockProcessedData{
+					Slot:        0,
+					BlockRoot:   [32]byte{},
+					SignedBlock: b,
+					Verified:    true,
+					Optimistic:  false,
+				},
+			},
+			&feed.Event{
+				Type: statefeed.NewHead,
+				Data: &ethpb.EventHead{
+					Slot:                      0,
+					Block:                     make([]byte, 32),
+					State:                     make([]byte, 32),
+					EpochTransition:           true,
+					PreviousDutyDependentRoot: make([]byte, 32),
+					CurrentDutyDependentRoot:  make([]byte, 32),
+					ExecutionOptimistic:       false,
+				},
+			},
+			&feed.Event{
+				Type: statefeed.Reorg,
+				Data: &ethpb.EventChainReorg{
+					Slot:                0,
+					Depth:               0,
+					OldHeadBlock:        make([]byte, 32),
+					NewHeadBlock:        make([]byte, 32),
+					OldHeadState:        make([]byte, 32),
+					NewHeadState:        make([]byte, 32),
+					Epoch:               0,
+					ExecutionOptimistic: false,
+				},
+			},
+			&feed.Event{
+				Type: statefeed.FinalizedCheckpoint,
+				Data: &ethpb.EventFinalizedCheckpoint{
+					Block:               make([]byte, 32),
+					State:               make([]byte, 32),
+					Epoch:               0,
+					ExecutionOptimistic: false,
+				},
+			},
 		}
 
 		go func() {
 			s.StreamEvents(w, request)
 		}()
-		// wait for initiation of StreamEvents
-		time.Sleep(100 * time.Millisecond)
-		s.StateNotifier.StateFeed().Send(&feed.Event{
-			Type: statefeed.NewHead,
-			Data: &ethpb.EventHead{
-				Slot:                      0,
-				Block:                     make([]byte, 32),
-				State:                     make([]byte, 32),
-				EpochTransition:           true,
-				PreviousDutyDependentRoot: make([]byte, 32),
-				CurrentDutyDependentRoot:  make([]byte, 32),
-				ExecutionOptimistic:       false,
-			},
-		})
-		s.StateNotifier.StateFeed().Send(&feed.Event{
-			Type: statefeed.FinalizedCheckpoint,
-			Data: &ethpb.EventFinalizedCheckpoint{
-				Block:               make([]byte, 32),
-				State:               make([]byte, 32),
-				Epoch:               0,
-				ExecutionOptimistic: false,
-			},
-		})
-		s.StateNotifier.StateFeed().Send(&feed.Event{
-			Type: statefeed.Reorg,
-			Data: &ethpb.EventChainReorg{
-				Slot:                0,
-				Depth:               0,
-				OldHeadBlock:        make([]byte, 32),
-				NewHeadBlock:        make([]byte, 32),
-				OldHeadState:        make([]byte, 32),
-				NewHeadState:        make([]byte, 32),
-				Epoch:               0,
-				ExecutionOptimistic: false,
-			},
-		})
-		b, err := blocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlock(&eth.SignedBeaconBlock{}))
-		require.NoError(t, err)
-		s.StateNotifier.StateFeed().Send(&feed.Event{
-			Type: statefeed.BlockProcessed,
-			Data: &statefeed.BlockProcessedData{
-				Slot:        0,
-				BlockRoot:   [32]byte{},
-				SignedBlock: b,
-				Verified:    true,
-				Optimistic:  false,
-			},
-		})
 
-		// wait for feed
-		time.Sleep(1 * time.Second)
-		request.Context().Done()
-
-		resp := w.Result()
-		body, err := io.ReadAll(resp.Body)
-		require.NoError(t, err)
-		require.NotNil(t, body)
-		assert.Equal(t, stateResult, string(body))
+		requireAllEventsReceived(t, stn, opn, events, topics, s, w)
 	})
 	t.Run("payload attributes", func(t *testing.T) {
 		type testCase struct {
 			name                      string
 			getState                  func() state.BeaconState
 			getBlock                  func() interfaces.SignedBeaconBlock
-			expected                  string
 			SetTrackedValidatorsCache func(*cache.TrackedValidatorsCache)
 		}
 		testCases := []testCase{
@@ -301,7 +347,6 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					require.NoError(t, err)
 					return b
 				},
-				expected: payloadAttributesBellatrixResult,
 			},
 			{
 				name: "capella",
@@ -315,7 +360,6 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					require.NoError(t, err)
 					return b
 				},
-				expected: payloadAttributesCapellaResult,
 			},
 			{
 				name: "deneb",
@@ -329,7 +373,6 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					require.NoError(t, err)
 					return b
 				},
-				expected: payloadAttributesDenebResult,
 			},
 			{
 				name: "electra",
@@ -343,7 +386,6 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					require.NoError(t, err)
 					return b
 				},
-				expected: payloadAttributesElectraResultWithTVC,
 				SetTrackedValidatorsCache: func(c *cache.TrackedValidatorsCache) {
 					c.Set(cache.TrackedValidator{
 						Active:       true,
@@ -368,9 +410,11 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 				Slot:  &currentSlot,
 			}
 
+			stn := mockChain.NewEventFeedWrapper()
+			opn := mockChain.NewEventFeedWrapper()
 			s := &Server{
-				StateNotifier:          &mockChain.MockStateNotifier{},
-				OperationNotifier:      &mockChain.MockOperationNotifier{},
+				StateNotifier:          &mockChain.SimpleNotifier{Feed: stn},
+				OperationNotifier:      &mockChain.SimpleNotifier{Feed: opn},
 				HeadFetcher:            mockChainService,
 				ChainInfoFetcher:       mockChainService,
 				TrackedValidatorsCache: cache.NewTrackedValidatorsCache(),
@@ -378,100 +422,76 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 			if tc.SetTrackedValidatorsCache != nil {
 				tc.SetTrackedValidatorsCache(s.TrackedValidatorsCache)
 			}
-
-			request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://example.com/eth/v1/events?topics=%s", PayloadAttributesTopic), nil)
-			w := &flushableResponseRecorder{
-				ResponseRecorder: httptest.NewRecorder(),
-			}
+			topics, err := newTopicRequest([]string{PayloadAttributesTopic})
+			require.NoError(t, err)
+			request := topics.testHttpRequest(t)
+			w := NewStreamingResponseWriterRecorder()
+			events := []*feed.Event{&feed.Event{Type: statefeed.MissedSlot}}
 
 			go func() {
 				s.StreamEvents(w, request)
 			}()
-			// wait for initiation of StreamEvents
-			time.Sleep(100 * time.Millisecond)
-			s.StateNotifier.StateFeed().Send(&feed.Event{Type: statefeed.MissedSlot})
-
-			// wait for feed
-			time.Sleep(1 * time.Second)
-			request.Context().Done()
-
-			resp := w.Result()
-			body, err := io.ReadAll(resp.Body)
-			require.NoError(t, err)
-			require.NotNil(t, body)
-			assert.Equal(t, tc.expected, string(body), "wrong result for "+tc.name)
+			requireAllEventsReceived(t, stn, opn, events, topics, s, w)
 		}
 	})
 }
 
-const operationsResult = `:
+func TestStuckReader(t *testing.T) {
+	topics, events := operationEventsFixtures(t)
+	require.Equal(t, 8, len(events))
+	// set eventFeedDepth to a number lower than the events we intend to send to force the server to drop the reader.
+	stn := mockChain.NewEventFeedWrapper()
+	opn := mockChain.NewEventFeedWrapper()
+	s := &Server{
+		StateNotifier:     &mockChain.SimpleNotifier{Feed: stn},
+		OperationNotifier: &mockChain.SimpleNotifier{Feed: opn},
+		EventFeedDepth:    len(events) - 1,
+	}
 
-event: attestation
-data: {"aggregation_bits":"0x00","data":{"slot":"0","index":"0","beacon_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","source":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"target":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"}},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	eventsWritten := make(chan struct{})
+	go func() {
+		for i := range events {
+			ev := events[i]
+			top := topicForEvent(ev)
+			if topicsForOpsFeed[top] {
+				err := opn.WaitForSubscription(ctx)
+				require.NoError(t, err)
+				s.OperationNotifier.OperationFeed().Send(ev)
+			} else {
+				err := stn.WaitForSubscription(ctx)
+				require.NoError(t, err)
+				s.StateNotifier.StateFeed().Send(ev)
+			}
+		}
+		close(eventsWritten)
+	}()
 
-event: attestation
-data: {"aggregation_bits":"0x00","data":{"slot":"0","index":"0","beacon_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","source":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"target":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"}},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}
+	request := topics.testHttpRequest(t)
+	w := NewStreamingResponseWriterRecorder()
 
-event: voluntary_exit
-data: {"message":{"epoch":"0","validator_index":"0"},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}
+	handlerFinished := make(chan struct{})
+	go func() {
+		s.StreamEvents(w, request)
+		close(handlerFinished)
+	}()
 
-event: contribution_and_proof
-data: {"message":{"aggregator_index":"0","contribution":{"slot":"0","beacon_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","subcommittee_index":"0","aggregation_bits":"0x00000000000000000000000000000000","signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"},"selection_proof":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}
+	// Make sure that the stream writer shut down when the reader failed to clear the write buffer.
+	select {
+	case <-handlerFinished:
+		// We expect the stream handler to max out the queue buffer and exit gracefully.
+		return
+	case <-ctx.Done():
+		t.Fatalf("context canceled / timed out waiting for handler completion, err=%v", ctx.Err())
+	}
 
-event: bls_to_execution_change
-data: {"message":{"validator_index":"0","from_bls_pubkey":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","to_execution_address":"0x0000000000000000000000000000000000000000"},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}
-
-event: blob_sidecar
-data: {"block_root":"0xc78009fdf07fc56a11f122370658a353aaa542ed63e44c4bc15ff4cd105ab33c","index":"0","slot":"0","kzg_commitment":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","versioned_hash":"0x01b0761f87b081d5cf10757ccc89f12be355c70e2e29df288b65b30710dcbcd1"}
-
-event: attester_slashing
-data: {"attestation_1":{"attesting_indices":["0","1"],"data":{"slot":"0","index":"0","beacon_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","source":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"target":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"}},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"},"attestation_2":{"attesting_indices":["0","1"],"data":{"slot":"0","index":"0","beacon_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","source":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"target":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"}},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}}
-
-event: proposer_slashing
-data: {"signed_header_1":{"message":{"slot":"0","proposer_index":"0","parent_root":"0x0000000000000000000000000000000000000000000000000000000000000000","state_root":"0x0000000000000000000000000000000000000000000000000000000000000000","body_root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"},"signed_header_2":{"message":{"slot":"0","proposer_index":"0","parent_root":"0x0000000000000000000000000000000000000000000000000000000000000000","state_root":"0x0000000000000000000000000000000000000000000000000000000000000000","body_root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}}
-
-`
-
-const stateResult = `:
-
-event: head
-data: {"slot":"0","block":"0x0000000000000000000000000000000000000000000000000000000000000000","state":"0x0000000000000000000000000000000000000000000000000000000000000000","epoch_transition":true,"execution_optimistic":false,"previous_duty_dependent_root":"0x0000000000000000000000000000000000000000000000000000000000000000","current_duty_dependent_root":"0x0000000000000000000000000000000000000000000000000000000000000000"}
-
-event: finalized_checkpoint
-data: {"block":"0x0000000000000000000000000000000000000000000000000000000000000000","state":"0x0000000000000000000000000000000000000000000000000000000000000000","epoch":"0","execution_optimistic":false}
-
-event: chain_reorg
-data: {"slot":"0","depth":"0","old_head_block":"0x0000000000000000000000000000000000000000000000000000000000000000","old_head_state":"0x0000000000000000000000000000000000000000000000000000000000000000","new_head_block":"0x0000000000000000000000000000000000000000000000000000000000000000","new_head_state":"0x0000000000000000000000000000000000000000000000000000000000000000","epoch":"0","execution_optimistic":false}
-
-event: block
-data: {"slot":"0","block":"0xeade62f0457b2fdf48e7d3fc4b60736688286be7c7a3ac4c9a16a5e0600bd9e4","execution_optimistic":false}
-
-`
-
-const payloadAttributesBellatrixResult = `:
-
-event: payload_attributes
-data: {"version":"bellatrix","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0x0000000000000000000000000000000000000000"}}}
-
-`
-
-const payloadAttributesCapellaResult = `:
-
-event: payload_attributes
-data: {"version":"capella","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0x0000000000000000000000000000000000000000","withdrawals":[]}}}
-
-`
-
-const payloadAttributesDenebResult = `:
-
-event: payload_attributes
-data: {"version":"deneb","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0x0000000000000000000000000000000000000000","withdrawals":[],"parent_beacon_block_root":"0xbef96cb938fd48b2403d3e662664325abb0102ed12737cbb80d717520e50cf4a"}}}
-
-`
-
-const payloadAttributesElectraResultWithTVC = `:
-
-event: payload_attributes
-data: {"version":"electra","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0xd2dbd02e4efe087d7d195de828b9dd25f19a89c9","withdrawals":[],"parent_beacon_block_root":"0xf2110e448638f41cb34514ecdbb49c055536cd5f715f1cb259d1287bb900853e"}}}
-
-`
+	// Also make sure all the events were written.
+	select {
+	case <-eventsWritten:
+		// We expect the stream handler to max out the queue buffer and exit gracefully.
+		return
+	case <-ctx.Done():
+		t.Fatalf("context canceled / timed out waiting to write all events, err=%v", ctx.Err())
+	}
+}

beacon-chain/rpc/eth/events/http_test.go

@@ -0,0 +1,75 @@
+package events
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+type StreamingResponseWriterRecorder struct {
+	http.ResponseWriter
+	r             io.Reader
+	w             io.Writer
+	statusWritten *int
+	status        chan int
+	bodyRecording []byte
+	flushed       bool
+}
+
+func (w *StreamingResponseWriterRecorder) StatusChan() chan int {
+	return w.status
+}
+
+func NewStreamingResponseWriterRecorder() *StreamingResponseWriterRecorder {
+	r, w := io.Pipe()
+	return &StreamingResponseWriterRecorder{
+		ResponseWriter: httptest.NewRecorder(),
+		r:              r,
+		w:              w,
+		status:         make(chan int, 1),
+	}
+}
+
+// Write implements http.ResponseWriter.
+func (w *StreamingResponseWriterRecorder) Write(data []byte) (int, error) {
+	w.WriteHeader(http.StatusOK)
+	n, err := w.w.Write(data)
+	if err != nil {
+		return n, err
+	}
+	return w.ResponseWriter.Write(data)
+}
+
+// WriteHeader implements http.ResponseWriter.
+func (w *StreamingResponseWriterRecorder) WriteHeader(statusCode int) {
+	if w.statusWritten != nil {
+		return
+	}
+	w.statusWritten = &statusCode
+	w.status <- statusCode
+	w.ResponseWriter.WriteHeader(statusCode)
+}
+
+func (w *StreamingResponseWriterRecorder) Body() io.Reader {
+	return w.r
+}
+
+func (w *StreamingResponseWriterRecorder) RequireStatus(t *testing.T, status int) {
+	if w.statusWritten == nil {
+		t.Fatal("WriteHeader was not called")
+	}
+	require.Equal(t, status, *w.statusWritten)
+}
+
+func (w *StreamingResponseWriterRecorder) Flush() {
+	fw, ok := w.ResponseWriter.(http.Flusher)
+	if ok {
+		fw.Flush()
+	}
+	w.flushed = true
+}
+
+var _ http.ResponseWriter = &StreamingResponseWriterRecorder{}

beacon-chain/rpc/eth/events/server.go

@@ -4,6 +4,8 @@
 package events
 
 import (
+	"time"
+
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	opfeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/operation"
@@ -18,4 +20,6 @@ type Server struct {
 	HeadFetcher            blockchain.HeadFetcher
 	ChainInfoFetcher       blockchain.ChainInfoFetcher
 	TrackedValidatorsCache *cache.TrackedValidatorsCache
+	KeepAliveInterval      time.Duration
+	EventFeedDepth         int
 }

beacon-chain/rpc/eth/light-client/BUILD.bazel

@@ -20,14 +20,12 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params: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/ssz:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v2:go_default_library",
+        "//proto/migration:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
@@ -55,7 +53,6 @@ go_test(
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
-        "//encoding/bytesutil:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/eth/v2:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",

beacon-chain/rpc/eth/light-client/handlers.go

@@ -47,7 +47,7 @@ func (s *Server) GetLightClientBootstrap(w http.ResponseWriter, req *http.Reques
 		return
 	}
 
-	bootstrap, err := createLightClientBootstrap(ctx, state, blk.Block())
+	bootstrap, err := createLightClientBootstrap(ctx, state, blk)
 	if err != nil {
 		httputil.HandleError(w, "could not get light client bootstrap: "+err.Error(), http.StatusInternalServerError)
 		return
@@ -204,6 +204,7 @@ func (s *Server) GetLightClientUpdatesByRange(w http.ResponseWriter, req *http.R
 			state,
 			block,
 			attestedState,
+			attestedBlock,
 			finalizedBlock,
 		)
 
@@ -267,7 +268,7 @@ func (s *Server) GetLightClientFinalityUpdate(w http.ResponseWriter, req *http.R
 		return
 	}
 
-	update, err := newLightClientFinalityUpdateFromBeaconState(ctx, st, block, attestedState, finalizedBlock)
+	update, err := newLightClientFinalityUpdateFromBeaconState(ctx, st, block, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
 		httputil.HandleError(w, "Could not get light client finality update: "+err.Error(), http.StatusInternalServerError)
 		return
@@ -312,7 +313,7 @@ func (s *Server) GetLightClientOptimisticUpdate(w http.ResponseWriter, req *http
 		return
 	}
 
-	update, err := newLightClientOptimisticUpdateFromBeaconState(ctx, st, block, attestedState)
+	update, err := newLightClientOptimisticUpdateFromBeaconState(ctx, st, block, attestedState, attestedBlock)
 	if err != nil {
 		httputil.HandleError(w, "Could not get light client optimistic update: "+err.Error(), http.StatusInternalServerError)
 		return

beacon-chain/rpc/eth/light-client/handlers_test.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -19,49 +20,29 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
 )
 
 func TestLightClientHandler_GetLightClientBootstrap_Altair(t *testing.T) {
-	helpers.ClearCache()
-	slot := primitives.Slot(params.BeaconConfig().AltairForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
+	l := util.NewTestLightClient(t).SetupTestAltair()
 
-	b := util.NewBeaconBlockAltair()
-	b.Block.StateRoot = bytesutil.PadTo([]byte("foo"), 32)
-	b.Block.Slot = slot
-
-	signedBlock, err := blocks.NewSignedBeaconBlock(b)
-
-	require.NoError(t, err)
-	header, err := signedBlock.Header()
+	slot := l.State.Slot()
+	stateRoot, err := l.State.HashTreeRoot(l.Ctx)
 	require.NoError(t, err)
 
-	r, err := b.Block.HashTreeRoot()
-	require.NoError(t, err)
-
-	bs, err := util.NewBeaconStateAltair(func(state *ethpb.BeaconStateAltair) error {
-		state.BlockRoots[0] = r[:]
-		return nil
-	})
-	require.NoError(t, err)
-
-	require.NoError(t, bs.SetSlot(slot))
-	require.NoError(t, bs.SetLatestBlockHeader(header.Header))
-
-	mockBlocker := &testutil.MockBlocker{BlockToReturn: signedBlock}
+	mockBlocker := &testutil.MockBlocker{BlockToReturn: l.Block}
 	mockChainService := &mock.ChainService{Optimistic: true, Slot: &slot}
 	s := &Server{
 		Stater: &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{
-			slot: bs,
+			slot: l.State,
 		}},
 		Blocker:     mockBlocker,
 		HeadFetcher: mockChainService,
 	}
 	request := httptest.NewRequest("GET", "http://foo.com/", nil)
-	request.SetPathValue("block_root", hexutil.Encode(r[:]))
+	request.SetPathValue("block_root", hexutil.Encode(stateRoot[:]))
 	writer := httptest.NewRecorder()
 	writer.Body = &bytes.Buffer{}
 
@@ -74,47 +55,35 @@ func TestLightClientHandler_GetLightClientBootstrap_Altair(t *testing.T) {
 	err = json.Unmarshal(resp.Data.Header, &respHeader)
 	require.NoError(t, err)
 	require.Equal(t, "altair", resp.Version)
-	require.Equal(t, hexutil.Encode(header.Header.BodyRoot), respHeader.Beacon.BodyRoot)
-	require.NotNil(t, resp.Data)
+
+	blockHeader, err := l.Block.Header()
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(blockHeader.Header.BodyRoot), respHeader.Beacon.BodyRoot)
+	require.Equal(t, strconv.FormatUint(uint64(blockHeader.Header.Slot), 10), respHeader.Beacon.Slot)
+
+	require.NotNil(t, resp.Data.CurrentSyncCommittee)
+	require.NotNil(t, resp.Data.CurrentSyncCommitteeBranch)
+
 }
 
 func TestLightClientHandler_GetLightClientBootstrap_Capella(t *testing.T) {
-	helpers.ClearCache()
-	slot := primitives.Slot(params.BeaconConfig().CapellaForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
+	l := util.NewTestLightClient(t).SetupTestCapella(false) // result is same for true and false
 
-	b := util.NewBeaconBlockCapella()
-	b.Block.StateRoot = bytesutil.PadTo([]byte("foo"), 32)
-	b.Block.Slot = slot
-
-	signedBlock, err := blocks.NewSignedBeaconBlock(b)
-
-	require.NoError(t, err)
-	header, err := signedBlock.Header()
+	slot := l.State.Slot()
+	stateRoot, err := l.State.HashTreeRoot(l.Ctx)
 	require.NoError(t, err)
 
-	r, err := b.Block.HashTreeRoot()
-	require.NoError(t, err)
-
-	bs, err := util.NewBeaconStateCapella(func(state *ethpb.BeaconStateCapella) error {
-		state.BlockRoots[0] = r[:]
-		return nil
-	})
-	require.NoError(t, err)
-
-	require.NoError(t, bs.SetSlot(slot))
-	require.NoError(t, bs.SetLatestBlockHeader(header.Header))
-
-	mockBlocker := &testutil.MockBlocker{BlockToReturn: signedBlock}
+	mockBlocker := &testutil.MockBlocker{BlockToReturn: l.Block}
 	mockChainService := &mock.ChainService{Optimistic: true, Slot: &slot}
 	s := &Server{
 		Stater: &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{
-			slot: bs,
+			slot: l.State,
 		}},
 		Blocker:     mockBlocker,
 		HeadFetcher: mockChainService,
 	}
 	request := httptest.NewRequest("GET", "http://foo.com/", nil)
-	request.SetPathValue("block_root", hexutil.Encode(r[:]))
+	request.SetPathValue("block_root", hexutil.Encode(stateRoot[:]))
 	writer := httptest.NewRecorder()
 	writer.Body = &bytes.Buffer{}
 
@@ -123,51 +92,38 @@ func TestLightClientHandler_GetLightClientBootstrap_Capella(t *testing.T) {
 	var resp structs.LightClientBootstrapResponse
 	err = json.Unmarshal(writer.Body.Bytes(), &resp)
 	require.NoError(t, err)
-	var respHeader structs.LightClientHeaderCapella
+	var respHeader structs.LightClientHeader
 	err = json.Unmarshal(resp.Data.Header, &respHeader)
 	require.NoError(t, err)
 	require.Equal(t, "capella", resp.Version)
-	require.Equal(t, hexutil.Encode(header.Header.BodyRoot), respHeader.Beacon.BodyRoot)
-	require.NotNil(t, resp.Data)
+
+	blockHeader, err := l.Block.Header()
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(blockHeader.Header.BodyRoot), respHeader.Beacon.BodyRoot)
+	require.Equal(t, strconv.FormatUint(uint64(blockHeader.Header.Slot), 10), respHeader.Beacon.Slot)
+
+	require.NotNil(t, resp.Data.CurrentSyncCommittee)
+	require.NotNil(t, resp.Data.CurrentSyncCommitteeBranch)
 }
 
 func TestLightClientHandler_GetLightClientBootstrap_Deneb(t *testing.T) {
-	helpers.ClearCache()
-	slot := primitives.Slot(params.BeaconConfig().DenebForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
+	l := util.NewTestLightClient(t).SetupTestDeneb(false) // result is same for true and false
 
-	b := util.NewBeaconBlockDeneb()
-	b.Block.StateRoot = bytesutil.PadTo([]byte("foo"), 32)
-	b.Block.Slot = slot
-
-	signedBlock, err := blocks.NewSignedBeaconBlock(b)
-
-	require.NoError(t, err)
-	header, err := signedBlock.Header()
+	slot := l.State.Slot()
+	stateRoot, err := l.State.HashTreeRoot(l.Ctx)
 	require.NoError(t, err)
 
-	r, err := b.Block.HashTreeRoot()
-	require.NoError(t, err)
-
-	bs, err := util.NewBeaconStateDeneb(func(state *ethpb.BeaconStateDeneb) error {
-		state.BlockRoots[0] = r[:]
-		return nil
-	})
-	require.NoError(t, err)
-
-	require.NoError(t, bs.SetSlot(slot))
-	require.NoError(t, bs.SetLatestBlockHeader(header.Header))
-
-	mockBlocker := &testutil.MockBlocker{BlockToReturn: signedBlock}
+	mockBlocker := &testutil.MockBlocker{BlockToReturn: l.Block}
 	mockChainService := &mock.ChainService{Optimistic: true, Slot: &slot}
 	s := &Server{
 		Stater: &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{
-			slot: bs,
+			slot: l.State,
 		}},
 		Blocker:     mockBlocker,
 		HeadFetcher: mockChainService,
 	}
 	request := httptest.NewRequest("GET", "http://foo.com/", nil)
-	request.SetPathValue("block_root", hexutil.Encode(r[:]))
+	request.SetPathValue("block_root", hexutil.Encode(stateRoot[:]))
 	writer := httptest.NewRecorder()
 	writer.Body = &bytes.Buffer{}
 
@@ -176,12 +132,58 @@ func TestLightClientHandler_GetLightClientBootstrap_Deneb(t *testing.T) {
 	var resp structs.LightClientBootstrapResponse
 	err = json.Unmarshal(writer.Body.Bytes(), &resp)
 	require.NoError(t, err)
-	var respHeader structs.LightClientHeaderDeneb
+	var respHeader structs.LightClientHeader
 	err = json.Unmarshal(resp.Data.Header, &respHeader)
 	require.NoError(t, err)
 	require.Equal(t, "deneb", resp.Version)
-	require.Equal(t, hexutil.Encode(header.Header.BodyRoot), respHeader.Beacon.BodyRoot)
-	require.NotNil(t, resp.Data)
+
+	blockHeader, err := l.Block.Header()
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(blockHeader.Header.BodyRoot), respHeader.Beacon.BodyRoot)
+	require.Equal(t, strconv.FormatUint(uint64(blockHeader.Header.Slot), 10), respHeader.Beacon.Slot)
+
+	require.NotNil(t, resp.Data.CurrentSyncCommittee)
+	require.NotNil(t, resp.Data.CurrentSyncCommitteeBranch)
+}
+
+func TestLightClientHandler_GetLightClientBootstrap_Electra(t *testing.T) {
+	l := util.NewTestLightClient(t).SetupTestElectra(false) // result is same for true and false
+
+	slot := l.State.Slot()
+	stateRoot, err := l.State.HashTreeRoot(l.Ctx)
+	require.NoError(t, err)
+
+	mockBlocker := &testutil.MockBlocker{BlockToReturn: l.Block}
+	mockChainService := &mock.ChainService{Optimistic: true, Slot: &slot}
+	s := &Server{
+		Stater: &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{
+			slot: l.State,
+		}},
+		Blocker:     mockBlocker,
+		HeadFetcher: mockChainService,
+	}
+	request := httptest.NewRequest("GET", "http://foo.com/", nil)
+	request.SetPathValue("block_root", hexutil.Encode(stateRoot[:]))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+
+	s.GetLightClientBootstrap(writer, request)
+	require.Equal(t, http.StatusOK, writer.Code)
+	var resp structs.LightClientBootstrapResponse
+	err = json.Unmarshal(writer.Body.Bytes(), &resp)
+	require.NoError(t, err)
+	var respHeader structs.LightClientHeader
+	err = json.Unmarshal(resp.Data.Header, &respHeader)
+	require.NoError(t, err)
+	require.Equal(t, "electra", resp.Version)
+
+	blockHeader, err := l.Block.Header()
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Encode(blockHeader.Header.BodyRoot), respHeader.Beacon.BodyRoot)
+	require.Equal(t, strconv.FormatUint(uint64(blockHeader.Header.Slot), 10), respHeader.Beacon.Slot)
+
+	require.NotNil(t, resp.Data.CurrentSyncCommittee)
+	require.NotNil(t, resp.Data.CurrentSyncCommitteeBranch)
 }
 
 func TestLightClientHandler_GetLightClientUpdatesByRangeAltair(t *testing.T) {

beacon-chain/rpc/eth/light-client/helpers.go

@@ -7,10 +7,9 @@ import (
 	"reflect"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/proto/migration"
 
 	lightclient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
-	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
-	"github.com/prysmaticlabs/prysm/v5/encoding/ssz"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -18,18 +17,17 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	v2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )
 
-func createLightClientBootstrap(ctx context.Context, state state.BeaconState, blk interfaces.ReadOnlyBeaconBlock) (*structs.LightClientBootstrap, error) {
+func createLightClientBootstrap(ctx context.Context, state state.BeaconState, blk interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientBootstrap, error) {
 	switch blk.Version() {
 	case version.Phase0:
 		return nil, fmt.Errorf("light client bootstrap is not supported for phase0")
 	case version.Altair, version.Bellatrix:
-		return createLightClientBootstrapAltair(ctx, state)
+		return createLightClientBootstrapAltair(ctx, state, blk)
 	case version.Capella:
 		return createLightClientBootstrapCapella(ctx, state, blk)
 	case version.Deneb, version.Electra:
@@ -38,24 +36,7 @@ func createLightClientBootstrap(ctx context.Context, state state.BeaconState, bl
 	return nil, fmt.Errorf("unsupported block version %s", version.String(blk.Version()))
 }
 
-// createLightClientBootstrapAltair - implements https://github.com/ethereum/consensus-specs/blob/3d235740e5f1e641d3b160c8688f26e7dc5a1894/specs/altair/light-client/full-node.md#create_light_client_bootstrap
-// def create_light_client_bootstrap(state: BeaconState) -> LightClientBootstrap:
-//
-//	assert compute_epoch_at_slot(state.slot) >= ALTAIR_FORK_EPOCH
-//	assert state.slot == state.latest_block_header.slot
-//
-//	return LightClientBootstrap(
-//	    header=BeaconBlockHeader(
-//	        slot=state.latest_block_header.slot,
-//	        proposer_index=state.latest_block_header.proposer_index,
-//	        parent_root=state.latest_block_header.parent_root,
-//	        state_root=hash_tree_root(state),
-//	        body_root=state.latest_block_header.body_root,
-//	    ),
-//	    current_sync_committee=state.current_sync_committee,
-//	    current_sync_committee_branch=compute_merkle_proof_for_state(state, CURRENT_SYNC_COMMITTEE_INDEX)
-//	)
-func createLightClientBootstrapAltair(ctx context.Context, state state.BeaconState) (*structs.LightClientBootstrap, error) {
+func createLightClientBootstrapAltair(ctx context.Context, state state.BeaconState, block interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientBootstrap, error) {
 	// assert compute_epoch_at_slot(state.slot) >= ALTAIR_FORK_EPOCH
 	if slots.ToEpoch(state.Slot()) < params.BeaconConfig().AltairForkEpoch {
 		return nil, fmt.Errorf("light client bootstrap is not supported before Altair, invalid slot %d", state.Slot())
@@ -67,55 +48,63 @@ func createLightClientBootstrapAltair(ctx context.Context, state state.BeaconSta
 		return nil, fmt.Errorf("state slot %d not equal to latest block header slot %d", state.Slot(), latestBlockHeader.Slot)
 	}
 
-	// Prepare data
+	// header.state_root = hash_tree_root(state)
+	stateRoot, err := state.HashTreeRoot(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get state root")
+	}
+	latestBlockHeader.StateRoot = stateRoot[:]
+
+	// assert hash_tree_root(header) == hash_tree_root(block.message)
+	latestBlockHeaderRoot, err := latestBlockHeader.HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get latest block header root")
+	}
+	beaconBlockRoot, err := block.Block().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get block root")
+	}
+	if latestBlockHeaderRoot != beaconBlockRoot {
+		return nil, fmt.Errorf("latest block header root %#x not equal to block root %#x", latestBlockHeaderRoot, beaconBlockRoot)
+	}
+
+	lightClientHeaderContainer, err := lightclient.BlockToLightClientHeader(block)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert block to light client header")
+	}
+	lightClientHeader := lightClientHeaderContainer.GetHeaderAltair()
+
+	apiLightClientHeader := &structs.LightClientHeader{
+		Beacon: structs.BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(lightClientHeader.Beacon)),
+	}
+
+	headerJSON, err := json.Marshal(apiLightClientHeader)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert header to raw message")
+	}
 	currentSyncCommittee, err := state.CurrentSyncCommittee()
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get current sync committee")
 	}
-
-	committee := structs.SyncCommitteeFromConsensus(currentSyncCommittee)
-
 	currentSyncCommitteeProof, err := state.CurrentSyncCommitteeProof(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get current sync committee proof")
 	}
 
-	branch := make([]string, fieldparams.NextSyncCommitteeBranchDepth)
+	branch := make([]string, fieldparams.SyncCommitteeBranchDepth)
 	for i, proof := range currentSyncCommitteeProof {
 		branch[i] = hexutil.Encode(proof)
 	}
-
-	beacon := structs.BeaconBlockHeaderFromConsensus(latestBlockHeader)
-	if beacon == nil {
-		return nil, fmt.Errorf("could not get beacon block header")
-	}
-	header := &structs.LightClientHeader{
-		Beacon: beacon,
-	}
-
-	// Above shared util function won't calculate state root, so we need to do it manually
-	stateRoot, err := state.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get state root")
-	}
-	header.Beacon.StateRoot = hexutil.Encode(stateRoot[:])
-
-	headerJson, err := json.Marshal(header)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not convert header to raw message")
-	}
-
-	// Return result
 	result := &structs.LightClientBootstrap{
-		Header:                     headerJson,
-		CurrentSyncCommittee:       committee,
+		Header:                     headerJSON,
+		CurrentSyncCommittee:       structs.SyncCommitteeFromConsensus(currentSyncCommittee),
 		CurrentSyncCommitteeBranch: branch,
 	}
 
 	return result, nil
 }
 
-func createLightClientBootstrapCapella(ctx context.Context, state state.BeaconState, block interfaces.ReadOnlyBeaconBlock) (*structs.LightClientBootstrap, error) {
+func createLightClientBootstrapCapella(ctx context.Context, state state.BeaconState, block interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientBootstrap, error) {
 	// assert compute_epoch_at_slot(state.slot) >= CAPELLA_FORK_EPOCH
 	if slots.ToEpoch(state.Slot()) < params.BeaconConfig().CapellaForkEpoch {
 		return nil, fmt.Errorf("creating Capella light client bootstrap is not supported before Capella, invalid slot %d", state.Slot())
@@ -127,111 +116,63 @@ func createLightClientBootstrapCapella(ctx context.Context, state state.BeaconSt
 		return nil, fmt.Errorf("state slot %d not equal to latest block header slot %d", state.Slot(), latestBlockHeader.Slot)
 	}
 
-	// Prepare data
+	// header.state_root = hash_tree_root(state)
+	stateRoot, err := state.HashTreeRoot(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get state root")
+	}
+	latestBlockHeader.StateRoot = stateRoot[:]
+
+	// assert hash_tree_root(header) == hash_tree_root(block.message)
+	latestBlockHeaderRoot, err := latestBlockHeader.HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get latest block header root")
+	}
+	beaconBlockRoot, err := block.Block().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get block root")
+	}
+	if latestBlockHeaderRoot != beaconBlockRoot {
+		return nil, fmt.Errorf("latest block header root %#x not equal to block root %#x", latestBlockHeaderRoot, beaconBlockRoot)
+	}
+
+	lightClientHeaderContainer, err := lightclient.BlockToLightClientHeader(block)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert block to light client header")
+	}
+	lightClientHeader := lightClientHeaderContainer.GetHeaderCapella()
+
+	apiLightClientHeader := &structs.LightClientHeader{
+		Beacon: structs.BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(lightClientHeader.Beacon)),
+	}
+
+	headerJSON, err := json.Marshal(apiLightClientHeader)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert header to raw message")
+	}
 	currentSyncCommittee, err := state.CurrentSyncCommittee()
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get current sync committee")
 	}
-
-	committee := structs.SyncCommitteeFromConsensus(currentSyncCommittee)
-
 	currentSyncCommitteeProof, err := state.CurrentSyncCommitteeProof(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get current sync committee proof")
 	}
 
-	branch := make([]string, fieldparams.NextSyncCommitteeBranchDepth)
+	branch := make([]string, fieldparams.SyncCommitteeBranchDepth)
 	for i, proof := range currentSyncCommitteeProof {
 		branch[i] = hexutil.Encode(proof)
 	}
-
-	beacon := structs.BeaconBlockHeaderFromConsensus(latestBlockHeader)
-
-	payloadInterface, err := block.Body().Execution()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get execution payload")
-	}
-	transactionsRoot, err := payloadInterface.TransactionsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		transactions, err := payloadInterface.Transactions()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions")
-		}
-		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions root")
-		}
-		transactionsRoot = transactionsRootArray[:]
-	} else if err != nil {
-		return nil, errors.Wrap(err, "could not get transactions root")
-	}
-	withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		withdrawals, err := payloadInterface.Withdrawals()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals")
-		}
-		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals root")
-		}
-		withdrawalsRoot = withdrawalsRootArray[:]
-	}
-	executionPayloadHeader := &structs.ExecutionPayloadHeaderCapella{
-		ParentHash:       hexutil.Encode(payloadInterface.ParentHash()),
-		FeeRecipient:     hexutil.Encode(payloadInterface.FeeRecipient()),
-		StateRoot:        hexutil.Encode(payloadInterface.StateRoot()),
-		ReceiptsRoot:     hexutil.Encode(payloadInterface.ReceiptsRoot()),
-		LogsBloom:        hexutil.Encode(payloadInterface.LogsBloom()),
-		PrevRandao:       hexutil.Encode(payloadInterface.PrevRandao()),
-		BlockNumber:      hexutil.EncodeUint64(payloadInterface.BlockNumber()),
-		GasLimit:         hexutil.EncodeUint64(payloadInterface.GasLimit()),
-		GasUsed:          hexutil.EncodeUint64(payloadInterface.GasUsed()),
-		Timestamp:        hexutil.EncodeUint64(payloadInterface.Timestamp()),
-		ExtraData:        hexutil.Encode(payloadInterface.ExtraData()),
-		BaseFeePerGas:    hexutil.Encode(payloadInterface.BaseFeePerGas()),
-		BlockHash:        hexutil.Encode(payloadInterface.BlockHash()),
-		TransactionsRoot: hexutil.Encode(transactionsRoot),
-		WithdrawalsRoot:  hexutil.Encode(withdrawalsRoot),
-	}
-
-	executionPayloadProof, err := blocks.PayloadProof(ctx, block)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get execution payload proof")
-	}
-	executionPayloadProofStr := make([]string, len(executionPayloadProof))
-	for i, proof := range executionPayloadProof {
-		executionPayloadProofStr[i] = hexutil.Encode(proof)
-	}
-	header := &structs.LightClientHeaderCapella{
-		Beacon:          beacon,
-		Execution:       executionPayloadHeader,
-		ExecutionBranch: executionPayloadProofStr,
-	}
-
-	// Above shared util function won't calculate state root, so we need to do it manually
-	stateRoot, err := state.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get state root")
-	}
-	header.Beacon.StateRoot = hexutil.Encode(stateRoot[:])
-
-	headerJson, err := json.Marshal(header)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not convert header to raw message")
-	}
-
-	// Return result
 	result := &structs.LightClientBootstrap{
-		Header:                     headerJson,
-		CurrentSyncCommittee:       committee,
+		Header:                     headerJSON,
+		CurrentSyncCommittee:       structs.SyncCommitteeFromConsensus(currentSyncCommittee),
 		CurrentSyncCommitteeBranch: branch,
 	}
 
 	return result, nil
 }
 
-func createLightClientBootstrapDeneb(ctx context.Context, state state.BeaconState, block interfaces.ReadOnlyBeaconBlock) (*structs.LightClientBootstrap, error) {
+func createLightClientBootstrapDeneb(ctx context.Context, state state.BeaconState, block interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientBootstrap, error) {
 	// assert compute_epoch_at_slot(state.slot) >= DENEB_FORK_EPOCH
 	if slots.ToEpoch(state.Slot()) < params.BeaconConfig().DenebForkEpoch {
 		return nil, fmt.Errorf("creating Deneb light client bootstrap is not supported before Deneb, invalid slot %d", state.Slot())
@@ -243,103 +184,61 @@ func createLightClientBootstrapDeneb(ctx context.Context, state state.BeaconStat
 		return nil, fmt.Errorf("state slot %d not equal to latest block header slot %d", state.Slot(), latestBlockHeader.Slot)
 	}
 
-	// Prepare data
-	currentSyncCommittee, err := state.CurrentSyncCommittee()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get current sync committee")
-	}
-
-	committee := structs.SyncCommitteeFromConsensus(currentSyncCommittee)
-
-	currentSyncCommitteeProof, err := state.CurrentSyncCommitteeProof(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get current sync committee proof")
-	}
-
-	branch := make([]string, fieldparams.NextSyncCommitteeBranchDepth)
-	for i, proof := range currentSyncCommitteeProof {
-		branch[i] = hexutil.Encode(proof)
-	}
-
-	beacon := structs.BeaconBlockHeaderFromConsensus(latestBlockHeader)
-
-	payloadInterface, err := block.Body().Execution()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get execution payload")
-	}
-	transactionsRoot, err := payloadInterface.TransactionsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		transactions, err := payloadInterface.Transactions()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions")
-		}
-		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get transactions root")
-		}
-		transactionsRoot = transactionsRootArray[:]
-	} else if err != nil {
-		return nil, errors.Wrap(err, "could not get transactions root")
-	}
-	withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
-	if errors.Is(err, consensus_types.ErrUnsupportedField) {
-		withdrawals, err := payloadInterface.Withdrawals()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals")
-		}
-		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals root")
-		}
-		withdrawalsRoot = withdrawalsRootArray[:]
-	}
-	executionPayloadHeader := &structs.ExecutionPayloadHeaderDeneb{
-		ParentHash:       hexutil.Encode(payloadInterface.ParentHash()),
-		FeeRecipient:     hexutil.Encode(payloadInterface.FeeRecipient()),
-		StateRoot:        hexutil.Encode(payloadInterface.StateRoot()),
-		ReceiptsRoot:     hexutil.Encode(payloadInterface.ReceiptsRoot()),
-		LogsBloom:        hexutil.Encode(payloadInterface.LogsBloom()),
-		PrevRandao:       hexutil.Encode(payloadInterface.PrevRandao()),
-		BlockNumber:      hexutil.EncodeUint64(payloadInterface.BlockNumber()),
-		GasLimit:         hexutil.EncodeUint64(payloadInterface.GasLimit()),
-		GasUsed:          hexutil.EncodeUint64(payloadInterface.GasUsed()),
-		Timestamp:        hexutil.EncodeUint64(payloadInterface.Timestamp()),
-		ExtraData:        hexutil.Encode(payloadInterface.ExtraData()),
-		BaseFeePerGas:    hexutil.Encode(payloadInterface.BaseFeePerGas()),
-		BlockHash:        hexutil.Encode(payloadInterface.BlockHash()),
-		TransactionsRoot: hexutil.Encode(transactionsRoot),
-		WithdrawalsRoot:  hexutil.Encode(withdrawalsRoot),
-	}
-
-	executionPayloadProof, err := blocks.PayloadProof(ctx, block)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get execution payload proof")
-	}
-	executionPayloadProofStr := make([]string, len(executionPayloadProof))
-	for i, proof := range executionPayloadProof {
-		executionPayloadProofStr[i] = hexutil.Encode(proof)
-	}
-	header := &structs.LightClientHeaderDeneb{
-		Beacon:          beacon,
-		Execution:       executionPayloadHeader,
-		ExecutionBranch: executionPayloadProofStr,
-	}
-
-	// Above shared util function won't calculate state root, so we need to do it manually
+	// header.state_root = hash_tree_root(state)
 	stateRoot, err := state.HashTreeRoot(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get state root")
 	}
-	header.Beacon.StateRoot = hexutil.Encode(stateRoot[:])
+	latestBlockHeader.StateRoot = stateRoot[:]
 
-	headerJson, err := json.Marshal(header)
+	// assert hash_tree_root(header) == hash_tree_root(block.message)
+	latestBlockHeaderRoot, err := latestBlockHeader.HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get latest block header root")
+	}
+	beaconBlockRoot, err := block.Block().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get block root")
+	}
+	if latestBlockHeaderRoot != beaconBlockRoot {
+		return nil, fmt.Errorf("latest block header root %#x not equal to block root %#x", latestBlockHeaderRoot, beaconBlockRoot)
+	}
+
+	lightClientHeaderContainer, err := lightclient.BlockToLightClientHeader(block)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert block to light client header")
+	}
+	lightClientHeader := lightClientHeaderContainer.GetHeaderDeneb()
+
+	apiLightClientHeader := &structs.LightClientHeader{
+		Beacon: structs.BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(lightClientHeader.Beacon)),
+	}
+
+	headerJSON, err := json.Marshal(apiLightClientHeader)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not convert header to raw message")
 	}
-	// Return result
+	currentSyncCommittee, err := state.CurrentSyncCommittee()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get current sync committee")
+	}
+	currentSyncCommitteeProof, err := state.CurrentSyncCommitteeProof(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get current sync committee proof")
+	}
+	var branch []string
+	switch block.Version() {
+	case version.Deneb:
+		branch = make([]string, fieldparams.SyncCommitteeBranchDepth)
+	case version.Electra:
+		branch = make([]string, fieldparams.SyncCommitteeBranchDepthElectra)
+	}
+	for i, proof := range currentSyncCommitteeProof {
+		branch[i] = hexutil.Encode(proof)
+	}
 	result := &structs.LightClientBootstrap{
-		Header:                     headerJson,
-		CurrentSyncCommittee:       committee,
+		Header:                     headerJSON,
+		CurrentSyncCommittee:       structs.SyncCommitteeFromConsensus(currentSyncCommittee),
 		CurrentSyncCommitteeBranch: branch,
 	}
 
@@ -351,9 +250,10 @@ func newLightClientUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 	finalizedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*structs.LightClientUpdate, error) {
-	result, err := lightclient.NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, finalizedBlock)
+	result, err := lightclient.NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
 		return nil, err
 	}
@@ -366,9 +266,10 @@ func newLightClientFinalityUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 	finalizedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*structs.LightClientFinalityUpdate, error) {
-	result, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, state, block, attestedState, finalizedBlock)
+	result, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
 		return nil, err
 	}
@@ -381,8 +282,9 @@ func newLightClientOptimisticUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*structs.LightClientOptimisticUpdate, error) {
-	result, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, state, block, attestedState)
+	result, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock)
 	if err != nil {
 		return nil, err
 	}
@@ -391,7 +293,7 @@ func newLightClientOptimisticUpdateFromBeaconState(
 }
 
 func IsSyncCommitteeUpdate(update *v2.LightClientUpdate) bool {
-	nextSyncCommitteeBranch := make([][]byte, fieldparams.NextSyncCommitteeBranchDepth)
+	nextSyncCommitteeBranch := make([][]byte, fieldparams.SyncCommitteeBranchDepth)
 	return !reflect.DeepEqual(update.NextSyncCommitteeBranch, nextSyncCommitteeBranch)
 }
 

beacon-chain/rpc/eth/light-client/helpers_test.go

@@ -13,7 +13,7 @@ import (
 
 // When the update has relevant sync committee
 func createNonEmptySyncCommitteeBranch() [][]byte {
-	res := make([][]byte, fieldparams.NextSyncCommitteeBranchDepth)
+	res := make([][]byte, fieldparams.SyncCommitteeBranchDepth)
 	res[0] = []byte("xyz")
 	return res
 }
@@ -101,7 +101,7 @@ func TestIsBetterUpdate(t *testing.T) {
 						}},
 					},
 				},
-				NextSyncCommitteeBranch: make([][]byte, fieldparams.NextSyncCommitteeBranchDepth),
+				NextSyncCommitteeBranch: make([][]byte, fieldparams.SyncCommitteeBranchDepth),
 				SignatureSlot:           9999,
 			},
 			newUpdate: &ethpbv2.LightClientUpdate{
@@ -147,7 +147,7 @@ func TestIsBetterUpdate(t *testing.T) {
 						}},
 					},
 				},
-				NextSyncCommitteeBranch: make([][]byte, fieldparams.NextSyncCommitteeBranchDepth),
+				NextSyncCommitteeBranch: make([][]byte, fieldparams.SyncCommitteeBranchDepth),
 				SignatureSlot:           9999,
 			},
 			expectedResult: false,

beacon-chain/rpc/eth/validator/handlers_block.go

@@ -287,6 +287,18 @@ func (s *Server) produceBlockV3(ctx context.Context, w http.ResponseWriter, r *h
 		handleProduceDenebV3(w, isSSZ, denebBlockContents, v1alpha1resp.PayloadValue, consensusBlockValue)
 		return
 	}
+	blindedElectraBlockContents, ok := v1alpha1resp.Block.(*eth.GenericBeaconBlock_BlindedElectra)
+	if ok {
+		w.Header().Set(api.VersionHeader, version.String(version.Electra))
+		handleProduceBlindedElectraV3(w, isSSZ, blindedElectraBlockContents, v1alpha1resp.PayloadValue, consensusBlockValue)
+		return
+	}
+	electraBlockContents, ok := v1alpha1resp.Block.(*eth.GenericBeaconBlock_Electra)
+	if ok {
+		w.Header().Set(api.VersionHeader, version.String(version.Electra))
+		handleProduceElectraV3(w, isSSZ, electraBlockContents, v1alpha1resp.PayloadValue, consensusBlockValue)
+		return
+	}
 }
 
 func getConsensusBlockValue(ctx context.Context, blockRewardsFetcher rewards.BlockRewardsFetcher, i interface{} /* block as argument */) (string, *httputil.DefaultJsonError) {
@@ -587,3 +599,74 @@ func handleProduceDenebV3(
 		Data:                    jsonBytes,
 	})
 }
+
+func handleProduceBlindedElectraV3(
+	w http.ResponseWriter,
+	isSSZ bool,
+	blk *eth.GenericBeaconBlock_BlindedElectra,
+	executionPayloadValue string,
+	consensusPayloadValue string,
+) {
+	if isSSZ {
+		sszResp, err := blk.BlindedElectra.MarshalSSZ()
+		if err != nil {
+			httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		httputil.WriteSsz(w, sszResp, "blindedElectraBlockContents.ssz")
+		return
+	}
+	blindedBlock, err := structs.BlindedBeaconBlockElectraFromConsensus(blk.BlindedElectra)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	jsonBytes, err := json.Marshal(blindedBlock)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	httputil.WriteJson(w, &structs.ProduceBlockV3Response{
+		Version:                 version.String(version.Electra),
+		ExecutionPayloadBlinded: true,
+		ExecutionPayloadValue:   executionPayloadValue,
+		ConsensusBlockValue:     consensusPayloadValue,
+		Data:                    jsonBytes,
+	})
+}
+
+func handleProduceElectraV3(
+	w http.ResponseWriter,
+	isSSZ bool,
+	blk *eth.GenericBeaconBlock_Electra,
+	executionPayloadValue string,
+	consensusBlockValue string,
+) {
+	if isSSZ {
+		sszResp, err := blk.Electra.MarshalSSZ()
+		if err != nil {
+			httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		httputil.WriteSsz(w, sszResp, "electraBlockContents.ssz")
+		return
+	}
+
+	blockContents, err := structs.BeaconBlockContentsElectraFromConsensus(blk.Electra)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	jsonBytes, err := json.Marshal(blockContents)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	httputil.WriteJson(w, &structs.ProduceBlockV3Response{
+		Version:                 version.String(version.Electra),
+		ExecutionPayloadBlinded: false,
+		ExecutionPayloadValue:   executionPayloadValue, // mev not available at this point
+		ConsensusBlockValue:     consensusBlockValue,
+		Data:                    jsonBytes,
+	})
+}

beacon-chain/rpc/eth/validator/handlers_block_test.go

@@ -308,6 +308,75 @@ func TestProduceBlockV2(t *testing.T) {
 		assert.Equal(t, http.StatusInternalServerError, e.Code)
 		assert.StringContains(t, "Prepared block is blinded", e.Message)
 	})
+	t.Run("Electra", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsElectra
+		err = json.Unmarshal([]byte(rpctesting.ElectraBlockContents), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.ToUnsigned())
+		require.NoError(t, err)
+
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: true,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v2/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV2(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"electra","execution_payload_blinded":false,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+	})
+	t.Run("Blinded Electra", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockElectra
+		err = json.Unmarshal([]byte(rpctesting.BlindedElectraBlock), &block)
+		require.NoError(t, err)
+
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: true,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				return block.Message.ToGeneric()
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v2/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV2(writer, request)
+		assert.Equal(t, http.StatusInternalServerError, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusInternalServerError, e.Code)
+		assert.StringContains(t, "Prepared block is blinded", e.Message)
+	})
 	t.Run("invalid query parameter slot empty", func(t *testing.T) {
 		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
 		server := &Server{
@@ -650,6 +719,76 @@ func TestProduceBlockV2SSZ(t *testing.T) {
 			BlockRewardFetcher:    rewardFetcher,
 		}
 
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v2/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV2(writer, request)
+		assert.Equal(t, http.StatusInternalServerError, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusInternalServerError, e.Code)
+		assert.StringContains(t, "Prepared block is blinded", e.Message)
+	})
+	t.Run("Electra", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsElectra
+		err = json.Unmarshal([]byte(rpctesting.ElectraBlockContents), &block)
+		require.NoError(t, err)
+
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: true,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				return block.ToUnsigned().ToGeneric()
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v2/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV2(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		g, err := block.ToUnsigned().ToGeneric()
+		require.NoError(t, err)
+		bl, ok := g.Block.(*eth.GenericBeaconBlock_Electra)
+		require.Equal(t, true, ok)
+		ssz, err := bl.Electra.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, string(ssz), writer.Body.String())
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+	})
+	t.Run("Blinded Electra", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockElectra
+		err = json.Unmarshal([]byte(rpctesting.BlindedElectraBlock), &block)
+		require.NoError(t, err)
+
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: true,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				return block.Message.ToGeneric()
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+
 		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v2/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
 		request.Header.Set("Accept", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
@@ -944,6 +1083,75 @@ func TestProduceBlindedBlock(t *testing.T) {
 		require.Equal(t, want, body)
 		require.Equal(t, "deneb", writer.Header().Get(api.VersionHeader))
 	})
+	t.Run("Electra", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsElectra
+		err = json.Unmarshal([]byte(rpctesting.ElectraBlockContents), &block)
+		require.NoError(t, err)
+
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				return block.ToUnsigned().ToGeneric()
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v1/validator/blinded_blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlindedBlock(writer, request)
+		assert.Equal(t, http.StatusInternalServerError, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusInternalServerError, e.Code)
+		assert.StringContains(t, "Prepared block is not blinded", e.Message)
+	})
+	t.Run("Blinded Electra", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockElectra
+		err = json.Unmarshal([]byte(rpctesting.BlindedElectraBlock), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.Message)
+		require.NoError(t, err)
+
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.Message.ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v1/validator/blinded_blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlindedBlock(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"electra","execution_payload_blinded":true,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+	})
 	t.Run("invalid query parameter slot empty", func(t *testing.T) {
 		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
 		server := &Server{
@@ -1309,6 +1517,82 @@ func TestProduceBlockV3(t *testing.T) {
 		require.Equal(t, "deneb", writer.Header().Get(api.VersionHeader))
 		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
 	})
+	t.Run("Electra", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsElectra
+		err := json.Unmarshal([]byte(rpctesting.ElectraBlockContents), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.ToUnsigned())
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"electra","execution_payload_blinded":false,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
+	t.Run("Blinded Electra", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockElectra
+		err := json.Unmarshal([]byte(rpctesting.BlindedElectraBlock), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.Message)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.Message.ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"electra","execution_payload_blinded":true,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "true", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 	t.Run("invalid query parameter slot empty", func(t *testing.T) {
 		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
 		server := &Server{
@@ -1697,4 +1981,86 @@ func TestProduceBlockV3SSZ(t *testing.T) {
 		require.Equal(t, "deneb", writer.Header().Get(api.VersionHeader))
 		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
 	})
+	t.Run("Electra", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsElectra
+		err := json.Unmarshal([]byte(rpctesting.ElectraBlockContents), &block)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		g, err := block.ToUnsigned().ToGeneric()
+		require.NoError(t, err)
+		bl, ok := g.Block.(*eth.GenericBeaconBlock_Electra)
+		require.Equal(t, true, ok)
+		ssz, err := bl.Electra.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, string(ssz), writer.Body.String())
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
+	t.Run("Blinded Electra", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockElectra
+		err := json.Unmarshal([]byte(rpctesting.BlindedElectraBlock), &block)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.Message.ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		g, err := block.Message.ToGeneric()
+		require.NoError(t, err)
+		bl, ok := g.Block.(*eth.GenericBeaconBlock_BlindedElectra)
+		require.Equal(t, true, ok)
+		ssz, err := bl.BlindedElectra.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, string(ssz), writer.Body.String())
+		require.Equal(t, "true", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 }

beacon-chain/rpc/prysm/beacon/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/db:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/rpc/eth/helpers:go_default_library",
         "//beacon-chain/rpc/eth/shared:go_default_library",
@@ -22,8 +23,10 @@ go_library(
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/sync:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
@@ -47,13 +50,16 @@ go_test(
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/rpc/lookup:go_default_library",
+        "//beacon-chain/rpc/prysm/testing:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/state/stategen/mock:go_default_library",
+        "//beacon-chain/sync/initial-sync/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

beacon-chain/rpc/prysm/beacon/handlers.go

@@ -15,7 +15,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/core"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/eth/shared"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	"github.com/prysmaticlabs/prysm/v5/network/httputil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -183,3 +185,52 @@ func (s *Server) GetChainHead(w http.ResponseWriter, r *http.Request) {
 	}
 	httputil.WriteJson(w, response)
 }
+
+func (s *Server) PublishBlobs(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.PublishBlobs")
+	defer span.End()
+	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
+		return
+	}
+
+	var req structs.PublishBlobsRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		httputil.HandleError(w, "Could not decode JSON request body", http.StatusBadRequest)
+		return
+	}
+	if req.BlobSidecars == nil {
+		httputil.HandleError(w, "Missing blob sidecars", http.StatusBadRequest)
+		return
+	}
+
+	root, err := bytesutil.DecodeHexWithLength(req.BlockRoot, 32)
+	if err != nil {
+		httputil.HandleError(w, "Could not decode block root: "+err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	for _, blobSidecar := range req.BlobSidecars.Sidecars {
+		sc, err := blobSidecar.ToConsensus()
+		if err != nil {
+			httputil.HandleError(w, "Could not decode blob sidecar: "+err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		readOnlySc, err := blocks.NewROBlobWithRoot(sc, bytesutil.ToBytes32(root))
+		if err != nil {
+			httputil.HandleError(w, "Could not create read-only blob: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		verifiedBlob := blocks.NewVerifiedROBlob(readOnlySc)
+		if err := s.BlobReceiver.ReceiveBlob(ctx, verifiedBlob); err != nil {
+			httputil.HandleError(w, "Could not receive blob: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		if err := s.Broadcaster.BroadcastBlob(ctx, sc.Index, sc); err != nil {
+			httputil.HandleError(w, "Failed to broadcast blob: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+	}
+}

beacon-chain/rpc/prysm/beacon/handlers_test.go

@@ -18,10 +18,13 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	dbTest "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/testing"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
+	mockp2p "github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/testing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/core"
+	rpctesting "github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/prysm/testing"
 	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
 	mockstategen "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen/mock"
+	mockSync "github.com/prysmaticlabs/prysm/v5/beacon-chain/sync/initial-sync/testing"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -870,3 +873,163 @@ func TestServer_GetChainHead(t *testing.T) {
 	assert.DeepEqual(t, hexutil.Encode(fRoot[:]), ch.FinalizedBlockRoot, "Unexpected FinalizedBlockRoot")
 	assert.Equal(t, false, ch.OptimisticStatus)
 }
+
+func TestPublishBlobs_InvalidJson(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.InvalidJson)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Could not decode JSON request body", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_MissingBlob(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestMissingBlob)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Could not decode blob sidecar", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_MissingSignedBlockHeader(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestMissingSignedBlockHeader)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Could not decode blob sidecar", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_MissingSidecars(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestMissingSidecars)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Missing blob sidecars", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_EmptySidecarsList(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestEmptySidecarsList)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusOK, writer.Code)
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_NullSidecar(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestNullSidecar)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Could not decode blob sidecar", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_SeveralFieldsMissing(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestSeveralFieldsMissing)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Could not decode blob sidecar", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_BadBlockRoot(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequestBadBlockRoot)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Could not decode block root", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs(t *testing.T) {
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequest)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusOK, writer.Code)
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 1)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), true)
+}

beacon-chain/rpc/prysm/beacon/server.go

@@ -3,6 +3,7 @@ package beacon
 import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain"
 	beacondb "github.com/prysmaticlabs/prysm/v5/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/core"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/lookup"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
@@ -20,4 +21,6 @@ type Server struct {
 	ChainInfoFetcher      blockchain.ChainInfoFetcher
 	FinalizationFetcher   blockchain.FinalizationFetcher
 	CoreService           *core.Service
+	Broadcaster           p2p.Broadcaster
+	BlobReceiver          blockchain.BlobReceiver
 }

beacon-chain/rpc/prysm/testing/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    testonly = True,
+    srcs = ["json.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/prysm/testing",
+    visibility = ["//visibility:public"],
+)

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_attestations.go

@@ -217,10 +217,10 @@ func (a proposerAtts) sort() (proposerAtts, error) {
 		return a, nil
 	}
 
-	if features.Get().EnableCommitteeAwarePacking {
-		return a.sortBySlotAndCommittee()
+	if features.Get().DisableCommitteeAwarePacking {
+		return a.sortByProfitabilityUsingMaxCover()
 	}
-	return a.sortByProfitabilityUsingMaxCover()
+	return a.sortBySlotAndCommittee()
 }
 
 // Separate attestations by slot, as slot number takes higher precedence when sorting.

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_attestations_test.go

@@ -21,6 +21,11 @@ import (
 )
 
 func TestProposer_ProposerAtts_sort(t *testing.T) {
+	feat := features.Get()
+	feat.DisableCommitteeAwarePacking = true
+	reset := features.InitWithReset(feat)
+	defer reset()
+
 	type testData struct {
 		slot primitives.Slot
 		bits bitfield.Bitlist
@@ -186,11 +191,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	}
 
 	t.Run("no atts", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		atts := getAtts([]testData{})
 		want := getAtts([]testData{})
 		atts, err := atts.sort()
@@ -201,11 +201,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	})
 
 	t.Run("single att", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		atts := getAtts([]testData{
 			{4, bitfield.Bitlist{0b11100000, 0b1}},
 		})
@@ -220,11 +215,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	})
 
 	t.Run("single att per slot", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		atts := getAtts([]testData{
 			{1, bitfield.Bitlist{0b11000000, 0b1}},
 			{4, bitfield.Bitlist{0b11100000, 0b1}},
@@ -241,10 +231,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	})
 
 	t.Run("two atts on one of the slots", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
 
 		atts := getAtts([]testData{
 			{1, bitfield.Bitlist{0b11000000, 0b1}},
@@ -263,11 +249,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	})
 
 	t.Run("compare to native sort", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		// The max-cover based approach will select 0b00001100 instead, despite lower bit count
 		// (since it has two new/unknown bits).
 		t.Run("max-cover", func(t *testing.T) {
@@ -289,11 +270,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	})
 
 	t.Run("multiple slots", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		atts := getAtts([]testData{
 			{2, bitfield.Bitlist{0b11100000, 0b1}},
 			{4, bitfield.Bitlist{0b11100000, 0b1}},
@@ -316,11 +292,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 	})
 
 	t.Run("follows max-cover", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		// Items at slot 4 must be first split into two lists by max-cover, with
 		// 0b10000011 being selected and 0b11100001 being leftover (despite naive bit count suggesting otherwise).
 		atts := getAtts([]testData{
@@ -350,11 +321,6 @@ func TestProposer_ProposerAtts_committeeAwareSort(t *testing.T) {
 
 func TestProposer_sort_DifferentCommittees(t *testing.T) {
 	t.Run("one att per committee", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		c1_a1 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b11111000, 0b1}, Data: &ethpb.AttestationData{CommitteeIndex: 1}})
 		c2_a1 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b11100000, 0b1}, Data: &ethpb.AttestationData{CommitteeIndex: 2}})
 		atts := proposerAtts{c1_a1, c2_a1}
@@ -364,11 +330,6 @@ func TestProposer_sort_DifferentCommittees(t *testing.T) {
 		assert.DeepEqual(t, want, atts)
 	})
 	t.Run("multiple atts per committee", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		c1_a1 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b11111100, 0b1}, Data: &ethpb.AttestationData{CommitteeIndex: 1}})
 		c1_a2 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b10000010, 0b1}, Data: &ethpb.AttestationData{CommitteeIndex: 1}})
 		c2_a1 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b11110000, 0b1}, Data: &ethpb.AttestationData{CommitteeIndex: 2}})
@@ -381,11 +342,6 @@ func TestProposer_sort_DifferentCommittees(t *testing.T) {
 		assert.DeepEqual(t, want, atts)
 	})
 	t.Run("multiple atts per committee, multiple slots", func(t *testing.T) {
-		feat := features.Get()
-		feat.EnableCommitteeAwarePacking = true
-		reset := features.InitWithReset(feat)
-		defer reset()
-
 		s2_c1_a1 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b11111100, 0b1}, Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 1}})
 		s2_c1_a2 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b10000010, 0b1}, Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 1}})
 		s2_c2_a1 := util.HydrateAttestation(&ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b11110000, 0b1}, Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 2}})

config/features/config.go

@@ -48,7 +48,7 @@ type Flags struct {
 	EnableDoppelGanger                  bool // EnableDoppelGanger enables doppelganger protection on startup for the validator.
 	EnableHistoricalSpaceRepresentation bool // EnableHistoricalSpaceRepresentation enables the saving of registry validators in separate buckets to save space
 	EnableBeaconRESTApi                 bool // EnableBeaconRESTApi enables experimental usage of the beacon REST API by the validator when querying a beacon node
-	EnableCommitteeAwarePacking         bool // EnableCommitteeAwarePacking TODO
+	DisableCommitteeAwarePacking        bool // DisableCommitteeAwarePacking changes the attestation packing algorithm to one that is not aware of attesting committees.
 	// Logging related toggles.
 	DisableGRPCConnectionLogs bool // Disables logging when a new grpc client has connected.
 	EnableFullSSZDataLogging  bool // Enables logging for full ssz data on rejected gossip messages
@@ -256,9 +256,9 @@ func ConfigureBeaconChain(ctx *cli.Context) error {
 		logEnabled(EnableQUIC)
 		cfg.EnableQUIC = true
 	}
-	if ctx.IsSet(EnableCommitteeAwarePacking.Name) {
-		logEnabled(EnableCommitteeAwarePacking)
-		cfg.EnableCommitteeAwarePacking = true
+	if ctx.IsSet(DisableCommitteeAwarePacking.Name) {
+		logEnabled(DisableCommitteeAwarePacking)
+		cfg.DisableCommitteeAwarePacking = true
 	}
 
 	cfg.AggregateIntervals = [3]time.Duration{aggregateFirstInterval.Value, aggregateSecondInterval.Value, aggregateThirdInterval.Value}

config/features/deprecated_flags.go

@@ -77,6 +77,12 @@ var (
 		Usage:  deprecatedUsage,
 		Hidden: true,
 	}
+
+	deprecatedEnableCommitteeAwarePacking = &cli.BoolFlag{
+		Name:   "enable-committee-aware-packing",
+		Usage:  deprecatedUsage,
+		Hidden: true,
+	}
 )
 
 // Deprecated flags for both the beacon node and validator client.
@@ -94,6 +100,7 @@ var deprecatedFlags = []cli.Flag{
 	deprecatedBeaconRPCGatewayProviderFlag,
 	deprecatedDisableGRPCGateway,
 	deprecatedEnableExperimentalState,
+	deprecatedEnableCommitteeAwarePacking,
 }
 
 // deprecatedBeaconFlags contains flags that are still used by other components

config/features/flags.go

@@ -166,9 +166,9 @@ var (
 		Name:  "enable-quic",
 		Usage: "Enables connection using the QUIC protocol for peers which support it.",
 	}
-	EnableCommitteeAwarePacking = &cli.BoolFlag{
-		Name:  "enable-committee-aware-packing",
-		Usage: "Changes the attestation packing algorithm to one that is aware of attesting committees.",
+	DisableCommitteeAwarePacking = &cli.BoolFlag{
+		Name:  "disable-committee-aware-packing",
+		Usage: "Changes the attestation packing algorithm to one that is not aware of attesting committees.",
 	}
 )
 
@@ -226,7 +226,7 @@ var BeaconChainFlags = append(deprecatedBeaconFlags, append(deprecatedFlags, []c
 	EnableLightClient,
 	BlobSaveFsync,
 	EnableQUIC,
-	EnableCommitteeAwarePacking,
+	DisableCommitteeAwarePacking,
 }...)...)
 
 // E2EBeaconChainFlags contains a list of the beacon chain feature flags to be tested in E2E.

config/fieldparams/mainnet.go

@@ -33,7 +33,10 @@ const (
 	BlobSize                              = 131072        // defined to match blob.size in bazel ssz codegen
 	BlobSidecarSize                       = 131928        // defined to match blob sidecar size in bazel ssz codegen
 	KzgCommitmentInclusionProofDepth      = 17            // Merkle proof depth for blob_kzg_commitments list item
-	NextSyncCommitteeBranchDepth          = 5             // NextSyncCommitteeBranchDepth defines the depth of the next sync committee branch.
+	ExecutionBranchDepth                  = 4             // ExecutionBranchDepth defines the number of leaves in a merkle proof of the execution payload header.
+	SyncCommitteeBranchDepth              = 5             // SyncCommitteeBranchDepth defines the number of leaves in a merkle proof of a sync committee.
+	SyncCommitteeBranchDepthElectra       = 6             // SyncCommitteeBranchDepthElectra defines the number of leaves in a merkle proof of a sync committee.
+	FinalityBranchDepth                   = 6             // FinalityBranchDepth defines the number of leaves in a merkle proof of the finalized checkpoint root.
 	PendingBalanceDepositsLimit           = 134217728     // Maximum number of pending balance deposits in the beacon state.
 	PendingPartialWithdrawalsLimit        = 134217728     // Maximum number of pending partial withdrawals in the beacon state.
 	PendingConsolidationsLimit            = 262144        // Maximum number of pending consolidations in the beacon state.

config/fieldparams/minimal.go

@@ -33,7 +33,10 @@ const (
 	BlobSize                              = 131072        // defined to match blob.size in bazel ssz codegen
 	BlobSidecarSize                       = 131928        // defined to match blob sidecar size in bazel ssz codegen
 	KzgCommitmentInclusionProofDepth      = 17            // Merkle proof depth for blob_kzg_commitments list item
-	NextSyncCommitteeBranchDepth          = 5             // NextSyncCommitteeBranchDepth defines the depth of the next sync committee branch.
+	ExecutionBranchDepth                  = 4             // ExecutionBranchDepth defines the number of leaves in a merkle proof of the execution payload header.
+	SyncCommitteeBranchDepth              = 5             // SyncCommitteeBranchDepth defines the number of leaves in a merkle proof of a sync committee.
+	SyncCommitteeBranchDepthElectra       = 6             // SyncCommitteeBranchDepthElectra defines the number of leaves in a merkle proof of a sync committee.
+	FinalityBranchDepth                   = 6             // FinalityBranchDepth defines the number of leaves in a merkle proof of the finalized checkpoint root.
 	PendingBalanceDepositsLimit           = 134217728     // Maximum number of pending balance deposits in the beacon state.
 	PendingPartialWithdrawalsLimit        = 64            // Maximum number of pending partial withdrawals in the beacon state.
 	PendingConsolidationsLimit            = 64            // Maximum number of pending consolidations in the beacon state.

config/params/BUILD.bazel

@@ -49,6 +49,7 @@ go_test(
         "mainnet_config_test.go",
         "testnet_config_test.go",
         "testnet_holesky_config_test.go",
+        "testnet_sepolia_config_test.go",
     ],
     data = glob(["*.yaml"]) + [
         "testdata/e2e_config.yaml",
@@ -57,6 +58,7 @@ go_test(
         "@consensus_spec_tests_minimal//:test_data",
         "@eth2_networks//:configs",
         "@holesky_testnet//:configs",
+        "@sepolia_testnet//:configs",
     ],
     embed = [":go_default_library"],
     gotags = ["develop"],

config/params/testnet_sepolia_config.go

@@ -11,11 +11,15 @@ func UseSepoliaNetworkConfig() {
 	cfg := BeaconNetworkConfig().Copy()
 	cfg.ContractDeploymentBlock = 1273020
 	cfg.BootstrapNodes = []string{
-		// EF boot nodes
+		"enr:-Ku4QDZ_rCowZFsozeWr60WwLgOfHzv1Fz2cuMvJqN5iJzLxKtVjoIURY42X_YTokMi3IGstW5v32uSYZyGUXj9Q_IECh2F0dG5ldHOIAAAAAAAAAACEZXRoMpCo_ujukAAAaf__________gmlkgnY0gmlwhIpEe5iJc2VjcDI1NmsxoQNHTpFdaNSCEWiN_QqT396nb0PzcUpLe3OVtLph-AciBYN1ZHCCIy0",
+		"enr:-Ku4QHRyRwEPT7s0XLYzJ_EeeWvZTXBQb4UCGy1F_3m-YtCNTtDlGsCMr4UTgo4uR89pv11uM-xq4w6GKfKhqU31hTgCh2F0dG5ldHOIAAAAAAAAAACEZXRoMpCo_ujukAAAaf__________gmlkgnY0gmlwhIrFM7WJc2VjcDI1NmsxoQI4diTwChN3zAAkarf7smOHCdFb1q3DSwdiQ_Lc_FdzFIN1ZHCCIy0",
+		"enr:-Ku4QOkvvf0u5Hg4-HhY-SJmEyft77G5h3rUM8VF_e-Hag5cAma3jtmFoX4WElLAqdILCA-UWFRN1ZCDJJVuEHrFeLkDh2F0dG5ldHOIAAAAAAAAAACEZXRoMpCo_ujukAAAaf__________gmlkgnY0gmlwhJK-AWeJc2VjcDI1NmsxoQLFcT5VE_NMiIC8Ll7GypWDnQ4UEmuzD7hF_Hf4veDJwIN1ZHCCIy0",
+		"enr:-Ku4QH6tYsHKITYeHUu5kdfXgEZWI18EWk_2RtGOn1jBPlx2UlS_uF3Pm5Dx7tnjOvla_zs-wwlPgjnEOcQDWXey51QCh2F0dG5ldHOIAAAAAAAAAACEZXRoMpCo_ujukAAAaf__________gmlkgnY0gmlwhIs7Mc6Jc2VjcDI1NmsxoQIET4Mlv9YzhrYhX_H9D7aWMemUrvki6W4J2Qo0YmFMp4N1ZHCCIy0",
+		"enr:-Ku4QDmz-4c1InchGitsgNk4qzorWMiFUoaPJT4G0IiF8r2UaevrekND1o7fdoftNucirj7sFFTTn2-JdC2Ej0p1Mn8Ch2F0dG5ldHOIAAAAAAAAAACEZXRoMpCo_ujukAAAaf__________gmlkgnY0gmlwhKpA-liJc2VjcDI1NmsxoQMpHP5U1DK8O_JQU6FadmWbE42qEdcGlllR8HcSkkfWq4N1ZHCCIy0",
+		"enr:-KO4QP7MmB3juk8rUjJHcUoxZDU9Np4FlW0HyDEGIjSO7GD9PbSsabu7713cWSUWKDkxIypIXg1A-6lG7ySRGOMZHeGCAmuEZXRoMpDTH2GRkAAAc___________gmlkgnY0gmlwhBSoyGOJc2VjcDI1NmsxoQNta5b_bexSSwwrGW2Re24MjfMntzFd0f2SAxQtMj3ueYN0Y3CCIyiDdWRwgiMo",
+		"enr:-KG4QJejf8KVtMeAPWFhN_P0c4efuwu1pZHELTveiXUeim6nKYcYcMIQpGxxdgT2Xp9h-M5pr9gn2NbbwEAtxzu50Y8BgmlkgnY0gmlwhEEVkQCDaXA2kCoBBPnAEJg4AAAAAAAAAAGJc2VjcDI1NmsxoQLEh_eVvk07AQABvLkTGBQTrrIOQkzouMgSBtNHIRUxOIN1ZHCCIyiEdWRwNoIjKA",
 		"enr:-Iq4QMCTfIMXnow27baRUb35Q8iiFHSIDBJh6hQM5Axohhf4b6Kr_cOCu0htQ5WvVqKvFgY28893DHAg8gnBAXsAVqmGAX53x8JggmlkgnY0gmlwhLKAlv6Jc2VjcDI1NmsxoQK6S-Cii_KmfFdUJL2TANL3ksaKUnNXvTCv1tLwXs0QgIN1ZHCCIyk",
-		"enr:-KG4QE5OIg5ThTjkzrlVF32WT_-XT14WeJtIz2zoTqLLjQhYAmJlnk4ItSoH41_2x0RX0wTFIe5GgjRzU2u7Q1fN4vADhGV0aDKQqP7o7pAAAHAyAAAAAAAAAIJpZIJ2NIJpcISlFsStiXNlY3AyNTZrMaEC-Rrd_bBZwhKpXzFCrStKp1q_HmGOewxY3KwM8ofAj_ODdGNwgiMog3VkcIIjKA",
-		// Teku boot node
-		"enr:-Ly4QFoZTWR8ulxGVsWydTNGdwEESueIdj-wB6UmmjUcm-AOPxnQi7wprzwcdo7-1jBW_JxELlUKJdJES8TDsbl1EdNlh2F0dG5ldHOI__78_v2bsV-EZXRoMpA2-lATkAAAcf__________gmlkgnY0gmlwhBLYJjGJc2VjcDI1NmsxoQI0gujXac9rMAb48NtMqtSTyHIeNYlpjkbYpWJw46PmYYhzeW5jbmV0cw-DdGNwgiMog3VkcIIjKA",
+		"enr:-L64QC9Hhov4DhQ7mRukTOz4_jHm4DHlGL726NWH4ojH1wFgEwSin_6H95Gs6nW2fktTWbPachHJ6rUFu0iJNgA0SB2CARqHYXR0bmV0c4j__________4RldGgykDb6UBOQAABx__________-CaWSCdjSCaXCEA-2vzolzZWNwMjU2azGhA17lsUg60R776rauYMdrAz383UUgESoaHEzMkvm4K6k6iHN5bmNuZXRzD4N0Y3CCIyiDdWRwgiMo",
 	}
 	OverrideBeaconNetworkConfig(cfg)
 }

config/params/testnet_sepolia_config_test.go

@@ -0,0 +1,28 @@
+package params_test
+
+import (
+	"path"
+	"testing"
+
+	"github.com/bazelbuild/rules_go/go/tools/bazel"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestSepoliaConfigMatchesUpstreamYaml(t *testing.T) {
+	presetFPs := presetsFilePath(t, "mainnet")
+	mn, err := params.ByName(params.MainnetName)
+	require.NoError(t, err)
+	cfg := mn.Copy()
+	for _, fp := range presetFPs {
+		cfg, err = params.UnmarshalConfigFile(fp, cfg)
+		require.NoError(t, err)
+	}
+	fPath, err := bazel.Runfile("external/sepolia_testnet")
+	require.NoError(t, err)
+	configFP := path.Join(fPath, "metadata", "config.yaml")
+	pcfg, err := params.UnmarshalConfigFile(configFP, nil)
+	require.NoError(t, err)
+	fields := fieldsFromYamls(t, append(presetFPs, configFP))
+	assertYamlFieldsMatch(t, "sepolia", fields, pcfg, params.SepoliaConfig())
+}

consensus-types/interfaces/BUILD.bazel

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "beacon_block.go",
         "error.go",
+        "light_client.go",
         "utils.go",
         "validator.go",
     ],

consensus-types/interfaces/light_client.go

@@ -0,0 +1,58 @@
+package interfaces
+
+import (
+	ssz "github.com/prysmaticlabs/fastssz"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+type LightClientExecutionBranch = [fieldparams.ExecutionBranchDepth][fieldparams.RootLength]byte
+type LightClientSyncCommitteeBranch = [fieldparams.SyncCommitteeBranchDepth][fieldparams.RootLength]byte
+type LightClientFinalityBranch = [fieldparams.FinalityBranchDepth][fieldparams.RootLength]byte
+
+type LightClientHeader interface {
+	ssz.Marshaler
+	Version() int
+	Beacon() *pb.BeaconBlockHeader
+	Execution() (ExecutionData, error)
+	ExecutionBranch() (LightClientExecutionBranch, error)
+}
+
+type LightClientBootstrap interface {
+	ssz.Marshaler
+	Version() int
+	Header() LightClientHeader
+	CurrentSyncCommittee() *pb.SyncCommittee
+	CurrentSyncCommitteeBranch() LightClientSyncCommitteeBranch
+}
+
+type LightClientUpdate interface {
+	ssz.Marshaler
+	Version() int
+	AttestedHeader() LightClientHeader
+	NextSyncCommittee() *pb.SyncCommittee
+	NextSyncCommitteeBranch() LightClientSyncCommitteeBranch
+	FinalizedHeader() LightClientHeader
+	FinalityBranch() LightClientFinalityBranch
+	SyncAggregate() *pb.SyncAggregate
+	SignatureSlot() primitives.Slot
+}
+
+type LightClientFinalityUpdate interface {
+	ssz.Marshaler
+	Version() int
+	AttestedHeader() LightClientHeader
+	FinalizedHeader() LightClientHeader
+	FinalityBranch() LightClientFinalityBranch
+	SyncAggregate() *pb.SyncAggregate
+	SignatureSlot() primitives.Slot
+}
+
+type LightClientOptimisticUpdate interface {
+	ssz.Marshaler
+	Version() int
+	AttestedHeader() LightClientHeader
+	SyncAggregate() *pb.SyncAggregate
+	SignatureSlot() primitives.Slot
+}

consensus-types/light-client/BUILD.bazel

@@ -0,0 +1,26 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "bootstrap.go",
+        "finality_update.go",
+        "header.go",
+        "helpers.go",
+        "optimistic_update.go",
+        "update.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v5/consensus-types/light-client",
+    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",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
+    ],
+)

consensus-types/light-client/bootstrap.go

@@ -0,0 +1,208 @@
+package light_client
+
+import (
+	"fmt"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	consensustypes "github.com/prysmaticlabs/prysm/v5/consensus-types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"google.golang.org/protobuf/proto"
+)
+
+func NewWrappedBootstrap(m proto.Message) (interfaces.LightClientBootstrap, error) {
+	if m == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	switch t := m.(type) {
+	case *pb.LightClientBootstrapAltair:
+		return NewWrappedBootstrapAltair(t)
+	case *pb.LightClientBootstrapCapella:
+		return NewWrappedBootstrapCapella(t)
+	case *pb.LightClientBootstrapDeneb:
+		return NewWrappedBootstrapDeneb(t)
+	default:
+		return nil, fmt.Errorf("cannot construct light client bootstrap from type %T", t)
+	}
+}
+
+type bootstrapAltair struct {
+	p                          *pb.LightClientBootstrapAltair
+	header                     interfaces.LightClientHeader
+	currentSyncCommitteeBranch interfaces.LightClientSyncCommitteeBranch
+}
+
+var _ interfaces.LightClientBootstrap = &bootstrapAltair{}
+
+func NewWrappedBootstrapAltair(p *pb.LightClientBootstrapAltair) (interfaces.LightClientBootstrap, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	header, err := NewWrappedHeaderAltair(p.Header)
+	if err != nil {
+		return nil, err
+	}
+	branch, err := createBranch[interfaces.LightClientSyncCommitteeBranch](
+		"sync committee",
+		p.CurrentSyncCommitteeBranch,
+		fieldparams.SyncCommitteeBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &bootstrapAltair{
+		p:                          p,
+		header:                     header,
+		currentSyncCommitteeBranch: branch,
+	}, nil
+}
+
+func (h *bootstrapAltair) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return h.p.MarshalSSZTo(dst)
+}
+
+func (h *bootstrapAltair) MarshalSSZ() ([]byte, error) {
+	return h.p.MarshalSSZ()
+}
+
+func (h *bootstrapAltair) SizeSSZ() int {
+	return h.p.SizeSSZ()
+}
+
+func (h *bootstrapAltair) Version() int {
+	return version.Altair
+}
+
+func (h *bootstrapAltair) Header() interfaces.LightClientHeader {
+	return h.header
+}
+
+func (h *bootstrapAltair) CurrentSyncCommittee() *pb.SyncCommittee {
+	return h.p.CurrentSyncCommittee
+}
+
+func (h *bootstrapAltair) CurrentSyncCommitteeBranch() interfaces.LightClientSyncCommitteeBranch {
+	return h.currentSyncCommitteeBranch
+}
+
+type bootstrapCapella struct {
+	p                          *pb.LightClientBootstrapCapella
+	header                     interfaces.LightClientHeader
+	currentSyncCommitteeBranch interfaces.LightClientSyncCommitteeBranch
+}
+
+var _ interfaces.LightClientBootstrap = &bootstrapCapella{}
+
+func NewWrappedBootstrapCapella(p *pb.LightClientBootstrapCapella) (interfaces.LightClientBootstrap, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	header, err := NewWrappedHeaderCapella(p.Header)
+	if err != nil {
+		return nil, err
+	}
+	branch, err := createBranch[interfaces.LightClientSyncCommitteeBranch](
+		"sync committee",
+		p.CurrentSyncCommitteeBranch,
+		fieldparams.SyncCommitteeBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &bootstrapCapella{
+		p:                          p,
+		header:                     header,
+		currentSyncCommitteeBranch: branch,
+	}, nil
+}
+
+func (h *bootstrapCapella) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return h.p.MarshalSSZTo(dst)
+}
+
+func (h *bootstrapCapella) MarshalSSZ() ([]byte, error) {
+	return h.p.MarshalSSZ()
+}
+
+func (h *bootstrapCapella) SizeSSZ() int {
+	return h.p.SizeSSZ()
+}
+
+func (h *bootstrapCapella) Version() int {
+	return version.Capella
+}
+
+func (h *bootstrapCapella) Header() interfaces.LightClientHeader {
+	return h.header
+}
+
+func (h *bootstrapCapella) CurrentSyncCommittee() *pb.SyncCommittee {
+	return h.p.CurrentSyncCommittee
+}
+
+func (h *bootstrapCapella) CurrentSyncCommitteeBranch() interfaces.LightClientSyncCommitteeBranch {
+	return h.currentSyncCommitteeBranch
+}
+
+type bootstrapDeneb struct {
+	p                          *pb.LightClientBootstrapDeneb
+	header                     interfaces.LightClientHeader
+	currentSyncCommitteeBranch interfaces.LightClientSyncCommitteeBranch
+}
+
+var _ interfaces.LightClientBootstrap = &bootstrapDeneb{}
+
+func NewWrappedBootstrapDeneb(p *pb.LightClientBootstrapDeneb) (interfaces.LightClientBootstrap, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	header, err := NewWrappedHeaderDeneb(p.Header)
+	if err != nil {
+		return nil, err
+	}
+	branch, err := createBranch[interfaces.LightClientSyncCommitteeBranch](
+		"sync committee",
+		p.CurrentSyncCommitteeBranch,
+		fieldparams.SyncCommitteeBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &bootstrapDeneb{
+		p:                          p,
+		header:                     header,
+		currentSyncCommitteeBranch: branch,
+	}, nil
+}
+
+func (h *bootstrapDeneb) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return h.p.MarshalSSZTo(dst)
+}
+
+func (h *bootstrapDeneb) MarshalSSZ() ([]byte, error) {
+	return h.p.MarshalSSZ()
+}
+
+func (h *bootstrapDeneb) SizeSSZ() int {
+	return h.p.SizeSSZ()
+}
+
+func (h *bootstrapDeneb) Version() int {
+	return version.Deneb
+}
+
+func (h *bootstrapDeneb) Header() interfaces.LightClientHeader {
+	return h.header
+}
+
+func (h *bootstrapDeneb) CurrentSyncCommittee() *pb.SyncCommittee {
+	return h.p.CurrentSyncCommittee
+}
+
+func (h *bootstrapDeneb) CurrentSyncCommitteeBranch() interfaces.LightClientSyncCommitteeBranch {
+	return h.currentSyncCommitteeBranch
+}

consensus-types/light-client/finality_update.go

@@ -0,0 +1,251 @@
+package light_client
+
+import (
+	"fmt"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	consensustypes "github.com/prysmaticlabs/prysm/v5/consensus-types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"google.golang.org/protobuf/proto"
+)
+
+func NewWrappedFinalityUpdate(m proto.Message) (interfaces.LightClientFinalityUpdate, error) {
+	if m == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	switch t := m.(type) {
+	case *pb.LightClientFinalityUpdateAltair:
+		return NewWrappedFinalityUpdateAltair(t)
+	case *pb.LightClientFinalityUpdateCapella:
+		return NewWrappedFinalityUpdateCapella(t)
+	case *pb.LightClientFinalityUpdateDeneb:
+		return NewWrappedFinalityUpdateDeneb(t)
+	default:
+		return nil, fmt.Errorf("cannot construct light client finality update from type %T", t)
+	}
+}
+
+type finalityUpdateAltair struct {
+	p               *pb.LightClientFinalityUpdateAltair
+	attestedHeader  interfaces.LightClientHeader
+	finalizedHeader interfaces.LightClientHeader
+	finalityBranch  interfaces.LightClientFinalityBranch
+}
+
+var _ interfaces.LightClientFinalityUpdate = &finalityUpdateAltair{}
+
+func NewWrappedFinalityUpdateAltair(p *pb.LightClientFinalityUpdateAltair) (interfaces.LightClientFinalityUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderAltair(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+	finalizedHeader, err := NewWrappedHeaderAltair(p.FinalizedHeader)
+	if err != nil {
+		return nil, err
+	}
+	branch, err := createBranch[interfaces.LightClientFinalityBranch](
+		"finality",
+		p.FinalityBranch,
+		fieldparams.FinalityBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &finalityUpdateAltair{
+		p:               p,
+		attestedHeader:  attestedHeader,
+		finalizedHeader: finalizedHeader,
+		finalityBranch:  branch,
+	}, nil
+}
+
+func (u *finalityUpdateAltair) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *finalityUpdateAltair) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *finalityUpdateAltair) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *finalityUpdateAltair) Version() int {
+	return version.Altair
+}
+
+func (u *finalityUpdateAltair) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *finalityUpdateAltair) FinalizedHeader() interfaces.LightClientHeader {
+	return u.finalizedHeader
+}
+
+func (u *finalityUpdateAltair) FinalityBranch() interfaces.LightClientFinalityBranch {
+	return u.finalityBranch
+}
+
+func (u *finalityUpdateAltair) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *finalityUpdateAltair) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}
+
+type finalityUpdateCapella struct {
+	p               *pb.LightClientFinalityUpdateCapella
+	attestedHeader  interfaces.LightClientHeader
+	finalizedHeader interfaces.LightClientHeader
+	finalityBranch  interfaces.LightClientFinalityBranch
+}
+
+var _ interfaces.LightClientFinalityUpdate = &finalityUpdateCapella{}
+
+func NewWrappedFinalityUpdateCapella(p *pb.LightClientFinalityUpdateCapella) (interfaces.LightClientFinalityUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderCapella(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+	finalizedHeader, err := NewWrappedHeaderCapella(p.FinalizedHeader)
+	if err != nil {
+		return nil, err
+	}
+	branch, err := createBranch[interfaces.LightClientFinalityBranch](
+		"finality",
+		p.FinalityBranch,
+		fieldparams.FinalityBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &finalityUpdateCapella{
+		p:               p,
+		attestedHeader:  attestedHeader,
+		finalizedHeader: finalizedHeader,
+		finalityBranch:  branch,
+	}, nil
+}
+
+func (u *finalityUpdateCapella) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *finalityUpdateCapella) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *finalityUpdateCapella) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *finalityUpdateCapella) Version() int {
+	return version.Capella
+}
+
+func (u *finalityUpdateCapella) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *finalityUpdateCapella) FinalizedHeader() interfaces.LightClientHeader {
+	return u.finalizedHeader
+}
+
+func (u *finalityUpdateCapella) FinalityBranch() interfaces.LightClientFinalityBranch {
+	return u.finalityBranch
+}
+
+func (u *finalityUpdateCapella) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *finalityUpdateCapella) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}
+
+type finalityUpdateDeneb struct {
+	p               *pb.LightClientFinalityUpdateDeneb
+	attestedHeader  interfaces.LightClientHeader
+	finalizedHeader interfaces.LightClientHeader
+	finalityBranch  interfaces.LightClientFinalityBranch
+}
+
+var _ interfaces.LightClientFinalityUpdate = &finalityUpdateDeneb{}
+
+func NewWrappedFinalityUpdateDeneb(p *pb.LightClientFinalityUpdateDeneb) (interfaces.LightClientFinalityUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderDeneb(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+	finalizedHeader, err := NewWrappedHeaderDeneb(p.FinalizedHeader)
+	if err != nil {
+		return nil, err
+	}
+	branch, err := createBranch[interfaces.LightClientFinalityBranch](
+		"finality",
+		p.FinalityBranch,
+		fieldparams.FinalityBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &finalityUpdateDeneb{
+		p:               p,
+		attestedHeader:  attestedHeader,
+		finalizedHeader: finalizedHeader,
+		finalityBranch:  branch,
+	}, nil
+}
+
+func (u *finalityUpdateDeneb) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *finalityUpdateDeneb) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *finalityUpdateDeneb) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *finalityUpdateDeneb) Version() int {
+	return version.Deneb
+}
+
+func (u *finalityUpdateDeneb) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *finalityUpdateDeneb) FinalizedHeader() interfaces.LightClientHeader {
+	return u.finalizedHeader
+}
+
+func (u *finalityUpdateDeneb) FinalityBranch() interfaces.LightClientFinalityBranch {
+	return u.finalityBranch
+}
+
+func (u *finalityUpdateDeneb) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *finalityUpdateDeneb) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}

consensus-types/light-client/header.go

@@ -0,0 +1,192 @@
+package light_client
+
+import (
+	"fmt"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	consensustypes "github.com/prysmaticlabs/prysm/v5/consensus-types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"google.golang.org/protobuf/proto"
+)
+
+func NewWrappedHeader(m proto.Message) (interfaces.LightClientHeader, error) {
+	if m == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	switch t := m.(type) {
+	case *pb.LightClientHeaderAltair:
+		return NewWrappedHeaderAltair(t)
+	case *pb.LightClientHeaderCapella:
+		return NewWrappedHeaderCapella(t)
+	case *pb.LightClientHeaderDeneb:
+		return NewWrappedHeaderDeneb(t)
+	default:
+		return nil, fmt.Errorf("cannot construct light client header from type %T", t)
+	}
+}
+
+type headerAltair struct {
+	p *pb.LightClientHeaderAltair
+}
+
+var _ interfaces.LightClientHeader = &headerAltair{}
+
+func NewWrappedHeaderAltair(p *pb.LightClientHeaderAltair) (interfaces.LightClientHeader, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	return &headerAltair{p: p}, nil
+}
+
+func (h *headerAltair) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return h.p.MarshalSSZTo(dst)
+}
+
+func (h *headerAltair) MarshalSSZ() ([]byte, error) {
+	return h.p.MarshalSSZ()
+}
+
+func (h *headerAltair) SizeSSZ() int {
+	return h.p.SizeSSZ()
+}
+
+func (h *headerAltair) Version() int {
+	return version.Altair
+}
+
+func (h *headerAltair) Beacon() *pb.BeaconBlockHeader {
+	return h.p.Beacon
+}
+
+func (h *headerAltair) Execution() (interfaces.ExecutionData, error) {
+	return nil, consensustypes.ErrNotSupported("Execution", version.Altair)
+}
+
+func (h *headerAltair) ExecutionBranch() (interfaces.LightClientExecutionBranch, error) {
+	return interfaces.LightClientExecutionBranch{}, consensustypes.ErrNotSupported("ExecutionBranch", version.Altair)
+}
+
+type headerCapella struct {
+	p               *pb.LightClientHeaderCapella
+	execution       interfaces.ExecutionData
+	executionBranch interfaces.LightClientExecutionBranch
+}
+
+var _ interfaces.LightClientHeader = &headerCapella{}
+
+func NewWrappedHeaderCapella(p *pb.LightClientHeaderCapella) (interfaces.LightClientHeader, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	execution, err := blocks.WrappedExecutionPayloadHeaderCapella(p.Execution)
+	if err != nil {
+		return nil, err
+	}
+
+	branch, err := createBranch[interfaces.LightClientExecutionBranch](
+		"execution",
+		p.ExecutionBranch,
+		fieldparams.ExecutionBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &headerCapella{
+		p:               p,
+		execution:       execution,
+		executionBranch: branch,
+	}, nil
+}
+
+func (h *headerCapella) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return h.p.MarshalSSZTo(dst)
+}
+
+func (h *headerCapella) MarshalSSZ() ([]byte, error) {
+	return h.p.MarshalSSZ()
+}
+
+func (h *headerCapella) SizeSSZ() int {
+	return h.p.SizeSSZ()
+}
+
+func (h *headerCapella) Version() int {
+	return version.Capella
+}
+
+func (h *headerCapella) Beacon() *pb.BeaconBlockHeader {
+	return h.p.Beacon
+}
+
+func (h *headerCapella) Execution() (interfaces.ExecutionData, error) {
+	return h.execution, nil
+}
+
+func (h *headerCapella) ExecutionBranch() (interfaces.LightClientExecutionBranch, error) {
+	return h.executionBranch, nil
+}
+
+type headerDeneb struct {
+	p               *pb.LightClientHeaderDeneb
+	execution       interfaces.ExecutionData
+	executionBranch interfaces.LightClientExecutionBranch
+}
+
+var _ interfaces.LightClientHeader = &headerDeneb{}
+
+func NewWrappedHeaderDeneb(p *pb.LightClientHeaderDeneb) (interfaces.LightClientHeader, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	execution, err := blocks.WrappedExecutionPayloadHeaderDeneb(p.Execution)
+	if err != nil {
+		return nil, err
+	}
+
+	branch, err := createBranch[interfaces.LightClientExecutionBranch](
+		"execution",
+		p.ExecutionBranch,
+		fieldparams.ExecutionBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &headerDeneb{
+		p:               p,
+		execution:       execution,
+		executionBranch: branch,
+	}, nil
+}
+
+func (h *headerDeneb) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return h.p.MarshalSSZTo(dst)
+}
+
+func (h *headerDeneb) MarshalSSZ() ([]byte, error) {
+	return h.p.MarshalSSZ()
+}
+
+func (h *headerDeneb) SizeSSZ() int {
+	return h.p.SizeSSZ()
+}
+
+func (h *headerDeneb) Version() int {
+	return version.Deneb
+}
+
+func (h *headerDeneb) Beacon() *pb.BeaconBlockHeader {
+	return h.p.Beacon
+}
+
+func (h *headerDeneb) Execution() (interfaces.ExecutionData, error) {
+	return h.execution, nil
+}
+
+func (h *headerDeneb) ExecutionBranch() (interfaces.LightClientExecutionBranch, error) {
+	return h.executionBranch, nil
+}

consensus-types/light-client/helpers.go

@@ -0,0 +1,30 @@
+package light_client
+
+import (
+	"fmt"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+)
+
+type branchConstraint interface {
+	~interfaces.LightClientExecutionBranch | ~interfaces.LightClientSyncCommitteeBranch | ~interfaces.LightClientFinalityBranch
+}
+
+func createBranch[T branchConstraint](name string, input [][]byte, depth int) (T, error) {
+	var zero T
+
+	if len(input) != depth {
+		return zero, fmt.Errorf("%s branch has %d leaves instead of expected %d", name, len(input), depth)
+	}
+	var branch T
+	for i, leaf := range input {
+		if len(leaf) != fieldparams.RootLength {
+			return zero, fmt.Errorf("%s branch leaf at index %d has length %d instead of expected %d", name, i, len(leaf), fieldparams.RootLength)
+		}
+		branch[i] = bytesutil.ToBytes32(leaf)
+	}
+
+	return branch, nil
+}

consensus-types/light-client/optimistic_update.go

@@ -0,0 +1,178 @@
+package light_client
+
+import (
+	"fmt"
+
+	consensustypes "github.com/prysmaticlabs/prysm/v5/consensus-types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"google.golang.org/protobuf/proto"
+)
+
+func NewWrappedOptimisticUpdate(m proto.Message) (interfaces.LightClientOptimisticUpdate, error) {
+	if m == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	switch t := m.(type) {
+	case *pb.LightClientOptimisticUpdateAltair:
+		return NewWrappedOptimisticUpdateAltair(t)
+	case *pb.LightClientOptimisticUpdateCapella:
+		return NewWrappedOptimisticUpdateCapella(t)
+	case *pb.LightClientOptimisticUpdateDeneb:
+		return NewWrappedOptimisticUpdateDeneb(t)
+	default:
+		return nil, fmt.Errorf("cannot construct light client optimistic update from type %T", t)
+	}
+}
+
+type OptimisticUpdateAltair struct {
+	p              *pb.LightClientOptimisticUpdateAltair
+	attestedHeader interfaces.LightClientHeader
+}
+
+var _ interfaces.LightClientOptimisticUpdate = &OptimisticUpdateAltair{}
+
+func NewWrappedOptimisticUpdateAltair(p *pb.LightClientOptimisticUpdateAltair) (interfaces.LightClientOptimisticUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderAltair(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+
+	return &OptimisticUpdateAltair{
+		p:              p,
+		attestedHeader: attestedHeader,
+	}, nil
+}
+
+func (u *OptimisticUpdateAltair) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *OptimisticUpdateAltair) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *OptimisticUpdateAltair) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *OptimisticUpdateAltair) Version() int {
+	return version.Altair
+}
+
+func (u *OptimisticUpdateAltair) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *OptimisticUpdateAltair) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *OptimisticUpdateAltair) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}
+
+type OptimisticUpdateCapella struct {
+	p              *pb.LightClientOptimisticUpdateCapella
+	attestedHeader interfaces.LightClientHeader
+}
+
+var _ interfaces.LightClientOptimisticUpdate = &OptimisticUpdateCapella{}
+
+func NewWrappedOptimisticUpdateCapella(p *pb.LightClientOptimisticUpdateCapella) (interfaces.LightClientOptimisticUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderCapella(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+
+	return &OptimisticUpdateCapella{
+		p:              p,
+		attestedHeader: attestedHeader,
+	}, nil
+}
+
+func (u *OptimisticUpdateCapella) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *OptimisticUpdateCapella) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *OptimisticUpdateCapella) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *OptimisticUpdateCapella) Version() int {
+	return version.Capella
+}
+
+func (u *OptimisticUpdateCapella) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *OptimisticUpdateCapella) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *OptimisticUpdateCapella) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}
+
+type OptimisticUpdateDeneb struct {
+	p              *pb.LightClientOptimisticUpdateDeneb
+	attestedHeader interfaces.LightClientHeader
+}
+
+var _ interfaces.LightClientOptimisticUpdate = &OptimisticUpdateDeneb{}
+
+func NewWrappedOptimisticUpdateDeneb(p *pb.LightClientOptimisticUpdateDeneb) (interfaces.LightClientOptimisticUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderDeneb(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+
+	return &OptimisticUpdateDeneb{
+		p:              p,
+		attestedHeader: attestedHeader,
+	}, nil
+}
+
+func (u *OptimisticUpdateDeneb) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *OptimisticUpdateDeneb) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *OptimisticUpdateDeneb) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *OptimisticUpdateDeneb) Version() int {
+	return version.Deneb
+}
+
+func (u *OptimisticUpdateDeneb) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *OptimisticUpdateDeneb) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *OptimisticUpdateDeneb) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}

consensus-types/light-client/update.go

@@ -0,0 +1,305 @@
+package light_client
+
+import (
+	"fmt"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	consensustypes "github.com/prysmaticlabs/prysm/v5/consensus-types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"google.golang.org/protobuf/proto"
+)
+
+func NewWrappedUpdate(m proto.Message) (interfaces.LightClientUpdate, error) {
+	if m == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	switch t := m.(type) {
+	case *pb.LightClientUpdateAltair:
+		return NewWrappedUpdateAltair(t)
+	case *pb.LightClientUpdateCapella:
+		return NewWrappedUpdateCapella(t)
+	case *pb.LightClientUpdateDeneb:
+		return NewWrappedUpdateDeneb(t)
+	default:
+		return nil, fmt.Errorf("cannot construct light client update from type %T", t)
+	}
+}
+
+type updateAltair struct {
+	p                       *pb.LightClientUpdateAltair
+	attestedHeader          interfaces.LightClientHeader
+	nextSyncCommitteeBranch interfaces.LightClientSyncCommitteeBranch
+	finalizedHeader         interfaces.LightClientHeader
+	finalityBranch          interfaces.LightClientFinalityBranch
+}
+
+var _ interfaces.LightClientUpdate = &updateAltair{}
+
+func NewWrappedUpdateAltair(p *pb.LightClientUpdateAltair) (interfaces.LightClientUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderAltair(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+	finalizedHeader, err := NewWrappedHeaderAltair(p.FinalizedHeader)
+	if err != nil {
+		return nil, err
+	}
+	scBranch, err := createBranch[interfaces.LightClientSyncCommitteeBranch](
+		"sync committee",
+		p.NextSyncCommitteeBranch,
+		fieldparams.SyncCommitteeBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+	finalityBranch, err := createBranch[interfaces.LightClientFinalityBranch](
+		"finality",
+		p.FinalityBranch,
+		fieldparams.FinalityBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &updateAltair{
+		p:                       p,
+		attestedHeader:          attestedHeader,
+		nextSyncCommitteeBranch: scBranch,
+		finalizedHeader:         finalizedHeader,
+		finalityBranch:          finalityBranch,
+	}, nil
+}
+
+func (u *updateAltair) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *updateAltair) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *updateAltair) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *updateAltair) Version() int {
+	return version.Altair
+}
+
+func (u *updateAltair) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *updateAltair) NextSyncCommittee() *pb.SyncCommittee {
+	return u.p.NextSyncCommittee
+}
+
+func (u *updateAltair) NextSyncCommitteeBranch() interfaces.LightClientSyncCommitteeBranch {
+	return u.nextSyncCommitteeBranch
+}
+
+func (u *updateAltair) FinalizedHeader() interfaces.LightClientHeader {
+	return u.finalizedHeader
+}
+
+func (u *updateAltair) FinalityBranch() interfaces.LightClientFinalityBranch {
+	return u.finalityBranch
+}
+
+func (u *updateAltair) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *updateAltair) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}
+
+type updateCapella struct {
+	p                       *pb.LightClientUpdateCapella
+	attestedHeader          interfaces.LightClientHeader
+	nextSyncCommitteeBranch interfaces.LightClientSyncCommitteeBranch
+	finalizedHeader         interfaces.LightClientHeader
+	finalityBranch          interfaces.LightClientFinalityBranch
+}
+
+var _ interfaces.LightClientUpdate = &updateCapella{}
+
+func NewWrappedUpdateCapella(p *pb.LightClientUpdateCapella) (interfaces.LightClientUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderCapella(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+	finalizedHeader, err := NewWrappedHeaderCapella(p.FinalizedHeader)
+	if err != nil {
+		return nil, err
+	}
+	scBranch, err := createBranch[interfaces.LightClientSyncCommitteeBranch](
+		"sync committee",
+		p.NextSyncCommitteeBranch,
+		fieldparams.SyncCommitteeBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+	finalityBranch, err := createBranch[interfaces.LightClientFinalityBranch](
+		"finality",
+		p.FinalityBranch,
+		fieldparams.FinalityBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &updateCapella{
+		p:                       p,
+		attestedHeader:          attestedHeader,
+		nextSyncCommitteeBranch: scBranch,
+		finalizedHeader:         finalizedHeader,
+		finalityBranch:          finalityBranch,
+	}, nil
+}
+
+func (u *updateCapella) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *updateCapella) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *updateCapella) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *updateCapella) Version() int {
+	return version.Capella
+}
+
+func (u *updateCapella) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *updateCapella) NextSyncCommittee() *pb.SyncCommittee {
+	return u.p.NextSyncCommittee
+}
+
+func (u *updateCapella) NextSyncCommitteeBranch() interfaces.LightClientSyncCommitteeBranch {
+	return u.nextSyncCommitteeBranch
+}
+
+func (u *updateCapella) FinalizedHeader() interfaces.LightClientHeader {
+	return u.finalizedHeader
+}
+
+func (u *updateCapella) FinalityBranch() interfaces.LightClientFinalityBranch {
+	return u.finalityBranch
+}
+
+func (u *updateCapella) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *updateCapella) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}
+
+type updateDeneb struct {
+	p                       *pb.LightClientUpdateDeneb
+	attestedHeader          interfaces.LightClientHeader
+	nextSyncCommitteeBranch interfaces.LightClientSyncCommitteeBranch
+	finalizedHeader         interfaces.LightClientHeader
+	finalityBranch          interfaces.LightClientFinalityBranch
+}
+
+var _ interfaces.LightClientUpdate = &updateDeneb{}
+
+func NewWrappedUpdateDeneb(p *pb.LightClientUpdateDeneb) (interfaces.LightClientUpdate, error) {
+	if p == nil {
+		return nil, consensustypes.ErrNilObjectWrapped
+	}
+	attestedHeader, err := NewWrappedHeaderDeneb(p.AttestedHeader)
+	if err != nil {
+		return nil, err
+	}
+	finalizedHeader, err := NewWrappedHeaderDeneb(p.FinalizedHeader)
+	if err != nil {
+		return nil, err
+	}
+	scBranch, err := createBranch[interfaces.LightClientSyncCommitteeBranch](
+		"sync committee",
+		p.NextSyncCommitteeBranch,
+		fieldparams.SyncCommitteeBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+	finalityBranch, err := createBranch[interfaces.LightClientFinalityBranch](
+		"finality",
+		p.FinalityBranch,
+		fieldparams.FinalityBranchDepth,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &updateDeneb{
+		p:                       p,
+		attestedHeader:          attestedHeader,
+		nextSyncCommitteeBranch: scBranch,
+		finalizedHeader:         finalizedHeader,
+		finalityBranch:          finalityBranch,
+	}, nil
+}
+
+func (u *updateDeneb) MarshalSSZTo(dst []byte) ([]byte, error) {
+	return u.p.MarshalSSZTo(dst)
+}
+
+func (u *updateDeneb) MarshalSSZ() ([]byte, error) {
+	return u.p.MarshalSSZ()
+}
+
+func (u *updateDeneb) SizeSSZ() int {
+	return u.p.SizeSSZ()
+}
+
+func (u *updateDeneb) Version() int {
+	return version.Deneb
+}
+
+func (u *updateDeneb) AttestedHeader() interfaces.LightClientHeader {
+	return u.attestedHeader
+}
+
+func (u *updateDeneb) NextSyncCommittee() *pb.SyncCommittee {
+	return u.p.NextSyncCommittee
+}
+
+func (u *updateDeneb) NextSyncCommitteeBranch() interfaces.LightClientSyncCommitteeBranch {
+	return u.nextSyncCommitteeBranch
+}
+
+func (u *updateDeneb) FinalizedHeader() interfaces.LightClientHeader {
+	return u.finalizedHeader
+}
+
+func (u *updateDeneb) FinalityBranch() interfaces.LightClientFinalityBranch {
+	return u.finalityBranch
+}
+
+func (u *updateDeneb) SyncAggregate() *pb.SyncAggregate {
+	return u.p.SyncAggregate
+}
+
+func (u *updateDeneb) SignatureSlot() primitives.Slot {
+	return u.p.SignatureSlot
+}

consensus-types/primitives/BUILD.bazel

@@ -9,6 +9,7 @@ go_library(
         "domain.go",
         "epoch.go",
         "execution_address.go",
+        "kzg.go",
         "payload_id.go",
         "randao.go",
         "slot.go",
@@ -21,6 +22,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//math:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
     ],

consensus-types/primitives/kzg.go

@@ -0,0 +1,15 @@
+package primitives
+
+import (
+	"crypto/sha256"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+const blobCommitmentVersionKZG uint8 = 0x01
+
+func ConvertKzgCommitmentToVersionedHash(commitment []byte) common.Hash {
+	versionedHash := sha256.Sum256(commitment)
+	versionedHash[0] = blobCommitmentVersionKZG
+	return versionedHash
+}

deps.bzl

@@ -2781,8 +2781,8 @@ def prysm_deps():
     go_repository(
         name = "com_github_prysmaticlabs_fastssz",
         importpath = "github.com/prysmaticlabs/fastssz",
-        sum = "h1:0LZAwwHnsZFfXm4IK4rzFV4N5IVSKZKLmuBMA4kAlFk=",
-        version = "v0.0.0-20240620202422-a981b8ef89d3",
+        sum = "h1:xuVAdtz5ShYblG2sPyb4gw01DF8InbOI/kBCQjk7NiM=",
+        version = "v0.0.0-20241008181541-518c4ce73516",
     )
     go_repository(
         name = "com_github_prysmaticlabs_go_bitfield",
@@ -2833,6 +2833,12 @@ def prysm_deps():
         sum = "h1:HxSrwun11U+LlmwpgM1kEqIqH90IT4N8auv/cD7QFJg=",
         version = "v0.8.0",
     )
+    go_repository(
+        name = "com_github_r3labs_sse_v2",
+        importpath = "github.com/r3labs/sse/v2",
+        sum = "h1:hFEkLLFY4LDifoHdiCN/LlGBAdVJYsANaLqNYa1l/v0=",
+        version = "v2.10.0",
+    )
     go_repository(
         name = "com_github_raulk_go_watchdog",
         importpath = "github.com/raulk/go-watchdog",
@@ -4304,6 +4310,12 @@ def prysm_deps():
         sum = "h1:stTHdEoWg1pQ8riaP5ROrjS6zy6wewH/Q2iwnLCQUXY=",
         version = "v1.0.0-20160220154919-db14e161995a",
     )
+    go_repository(
+        name = "in_gopkg_cenkalti_backoff_v1",
+        importpath = "gopkg.in/cenkalti/backoff.v1",
+        sum = "h1:Arh75ttbsvlpVA7WtVpH4u9h6Zl46xuptxqLxPiSo4Y=",
+        version = "v1.1.0",
+    )
     go_repository(
         name = "in_gopkg_check_v1",
         importpath = "gopkg.in/check.v1",

go.mod

@@ -62,10 +62,11 @@ require (
 	github.com/prometheus/client_golang v1.20.0
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/prom2json v1.3.0
-	github.com/prysmaticlabs/fastssz v0.0.0-20240620202422-a981b8ef89d3
+	github.com/prysmaticlabs/fastssz v0.0.0-20241008181541-518c4ce73516
 	github.com/prysmaticlabs/go-bitfield v0.0.0-20240328144219-a1caa50c3a1e
 	github.com/prysmaticlabs/prombbolt v0.0.0-20210126082820-9b7adba6db7c
 	github.com/prysmaticlabs/protoc-gen-go-cast v0.0.0-20230228205207-28762a7b9294
+	github.com/r3labs/sse/v2 v2.10.0
 	github.com/rs/cors v1.7.0
 	github.com/schollz/progressbar/v3 v3.3.4
 	github.com/sirupsen/logrus v1.9.0
@@ -259,6 +260,7 @@ require (
 	golang.org/x/term v0.23.0 // indirect
 	golang.org/x/text v0.17.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
+	gopkg.in/cenkalti/backoff.v1 v1.1.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect

go.sum

@@ -897,8 +897,8 @@ github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0leargg
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/prometheus/prom2json v1.3.0 h1:BlqrtbT9lLH3ZsOVhXPsHzFrApCTKRifB7gjJuypu6Y=
 github.com/prometheus/prom2json v1.3.0/go.mod h1:rMN7m0ApCowcoDlypBHlkNbp5eJQf/+1isKykIP5ZnM=
-github.com/prysmaticlabs/fastssz v0.0.0-20240620202422-a981b8ef89d3 h1:0LZAwwHnsZFfXm4IK4rzFV4N5IVSKZKLmuBMA4kAlFk=
-github.com/prysmaticlabs/fastssz v0.0.0-20240620202422-a981b8ef89d3/go.mod h1:h2OlIZD/M6wFvV3YMZbW16lFgh3Rsye00G44J2cwLyU=
+github.com/prysmaticlabs/fastssz v0.0.0-20241008181541-518c4ce73516 h1:xuVAdtz5ShYblG2sPyb4gw01DF8InbOI/kBCQjk7NiM=
+github.com/prysmaticlabs/fastssz v0.0.0-20241008181541-518c4ce73516/go.mod h1:h2OlIZD/M6wFvV3YMZbW16lFgh3Rsye00G44J2cwLyU=
 github.com/prysmaticlabs/go-bitfield v0.0.0-20210108222456-8e92c3709aa0/go.mod h1:hCwmef+4qXWjv0jLDbQdWnL0Ol7cS7/lCSS26WR+u6s=
 github.com/prysmaticlabs/go-bitfield v0.0.0-20240328144219-a1caa50c3a1e h1:ATgOe+abbzfx9kCPeXIW4fiWyDdxlwHw07j8UGhdTd4=
 github.com/prysmaticlabs/go-bitfield v0.0.0-20240328144219-a1caa50c3a1e/go.mod h1:wmuf/mdK4VMD+jA9ThwcUKjg3a2XWM9cVfFYjDyY4j4=
@@ -914,6 +914,8 @@ github.com/quic-go/quic-go v0.46.0 h1:uuwLClEEyk1DNvchH8uCByQVjo3yKL9opKulExNDs7
 github.com/quic-go/quic-go v0.46.0/go.mod h1:1dLehS7TIR64+vxGR70GDcatWTOtMX2PUtnKsjbTurI=
 github.com/quic-go/webtransport-go v0.8.0 h1:HxSrwun11U+LlmwpgM1kEqIqH90IT4N8auv/cD7QFJg=
 github.com/quic-go/webtransport-go v0.8.0/go.mod h1:N99tjprW432Ut5ONql/aUhSLT0YVSlwHohQsuac9WaM=
+github.com/r3labs/sse/v2 v2.10.0 h1:hFEkLLFY4LDifoHdiCN/LlGBAdVJYsANaLqNYa1l/v0=
+github.com/r3labs/sse/v2 v2.10.0/go.mod h1:Igau6Whc+F17QUgML1fYe1VPZzTV6EMCnYktEmkNJ7I=
 github.com/raulk/go-watchdog v1.3.0 h1:oUmdlHxdkXRJlwfG0O9omj8ukerm8MEQavSiDTEtBsk=
 github.com/raulk/go-watchdog v1.3.0/go.mod h1:fIvOnLbF0b0ZwkB9YU4mOW9Did//4vPZtDqv66NfsMU=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
@@ -1223,6 +1225,7 @@ golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20190628185345-da137c7871d7/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20190724013045-ca1201d0de80/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20191116160921-f9c825593386/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20191209160850-c0dbc17a3553/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200114155413-6afb5195e5aa/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
@@ -1607,6 +1610,8 @@ google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6h
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/bsm/ratelimit.v1 v1.0.0-20160220154919-db14e161995a/go.mod h1:KF9sEfUPAXdG8Oev9e99iLGnl2uJMjc5B+4y3O7x610=
+gopkg.in/cenkalti/backoff.v1 v1.1.0 h1:Arh75ttbsvlpVA7WtVpH4u9h6Zl46xuptxqLxPiSo4Y=
+gopkg.in/cenkalti/backoff.v1 v1.1.0/go.mod h1:J6Vskwqd+OMVJl8C33mmtxTBs2gyzfv7UDAkHu8BrjI=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

proto/eth/v1/gateway.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: 13c946aa898cca1afa84687b619bc5a10fc79a46340e98dcfb07dde835d39a0c
+// Hash: 2874e1dadeb47411763f48fe31e5daaa91ac663e796933d9a508c2e7be94fa5e
 package v1
 
 import (
@@ -2395,7 +2395,10 @@ func (v *Validator) UnmarshalSSZ(buf []byte) error {
 	v.EffectiveBalance = ssz.UnmarshallUint64(buf[80:88])
 
 	// Field (3) 'Slashed'
-	v.Slashed = ssz.UnmarshalBool(buf[88:89])
+	v.Slashed, err = ssz.DecodeBool(buf[88:89])
+	if err != nil {
+		return err
+	}
 
 	// Field (4) 'ActivationEligibilityEpoch'
 	v.ActivationEligibilityEpoch = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Epoch(ssz.UnmarshallUint64(buf[89:97]))

proto/eth/v2/grpc.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: bc8a0f7f6c8dadac6bcb0eaab2dea4888cc44c5b3f4fe9998a71e15f1a059399
+// Hash: 298a6e797d2a244a4eee0e60b198b11fd30b4b8596a8a5b911dd2e14fafebdad
 package eth
 
 import (

proto/prysm/v1alpha1/BUILD.bazel

@@ -81,6 +81,11 @@ ssz_altair_objs = [
     "BeaconBlockBodyAltair",
     "BeaconStateAltair",
     "ContributionAndProof",
+    "LightClientBootstrapAltair",
+    "LightClientFinalityUpdateAltair",
+    "LightClientHeaderAltair",
+    "LightClientOptimisticUpdateAltair",
+    "LightClientUpdateAltair",
     "SignedBeaconBlockAltair",
     "SignedContributionAndProof",
     "SyncAggregate",
@@ -110,6 +115,11 @@ ssz_capella_objs = [
     "BlindedBeaconBlockCapella",
     "BuilderBidCapella",
     "HistoricalSummary",
+    "LightClientBootstrapCapella",
+    "LightClientFinalityUpdateCapella",
+    "LightClientHeaderCapella",
+    "LightClientOptimisticUpdateCapella",
+    "LightClientUpdateCapella",
     "SignedBLSToExecutionChange",
     "SignedBeaconBlockCapella",
     "SignedBlindedBeaconBlockCapella",
@@ -127,6 +137,11 @@ ssz_deneb_objs = [
     "BlobSidecar",
     "BlobSidecars",
     "BuilderBidDeneb",
+    "LightClientBootstrapDeneb",
+    "LightClientFinalityUpdateDeneb",
+    "LightClientHeaderDeneb",
+    "LightClientOptimisticUpdateDeneb",
+    "LightClientUpdateDeneb",
     "SignedBeaconBlockContentsDeneb",
     "SignedBeaconBlockDeneb",
     "SignedBlindedBeaconBlockDeneb",
@@ -136,7 +151,8 @@ ssz_electra_objs = [
     "AggregateAttestationAndProofElectra",
     "AttestationElectra",
     "AttesterSlashingElectra",
-    "BeaconBlockElectra",
+    "BeaconBlockBodyElectra",
+    "BeaconBlockContentsElectra",
     "BeaconBlockElectra",
     "BeaconStateElectra",
     "BlindedBeaconBlockBodyElectra",
@@ -333,6 +349,7 @@ ssz_proto_files(
         "beacon_block.proto",
         "beacon_state.proto",
         "blobs.proto",
+        "light_client.proto",
         "sync_committee.proto",
         "withdrawals.proto",
     ],

proto/prysm/v1alpha1/altair.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: bb838fc0c2dfdadd4a8274dd1b438b1051f7b84d7c8e7470900621284dba8f43
+// Hash: 18a07a11eb3d1daaafe0b6b1ac8934e9333ea6eceed7d5ef30166b9c2fb50d39
 package eth
 
 import (
@@ -1747,6 +1747,651 @@ func (s *SyncAggregatorSelectionData) HashTreeRootWith(hh *ssz.Hasher) (err erro
 	return
 }
 
+// MarshalSSZ ssz marshals the LightClientHeaderAltair object
+func (l *LightClientHeaderAltair) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientHeaderAltair object to a target array
+func (l *LightClientHeaderAltair) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+
+	// Field (0) 'Beacon'
+	if l.Beacon == nil {
+		l.Beacon = new(BeaconBlockHeader)
+	}
+	if dst, err = l.Beacon.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientHeaderAltair object
+func (l *LightClientHeaderAltair) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size != 112 {
+		return ssz.ErrSize
+	}
+
+	// Field (0) 'Beacon'
+	if l.Beacon == nil {
+		l.Beacon = new(BeaconBlockHeader)
+	}
+	if err = l.Beacon.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientHeaderAltair object
+func (l *LightClientHeaderAltair) SizeSSZ() (size int) {
+	size = 112
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientHeaderAltair object
+func (l *LightClientHeaderAltair) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientHeaderAltair object with a hasher
+func (l *LightClientHeaderAltair) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Beacon'
+	if err = l.Beacon.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientBootstrapAltair object
+func (l *LightClientBootstrapAltair) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientBootstrapAltair object to a target array
+func (l *LightClientBootstrapAltair) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+
+	// Field (0) 'Header'
+	if l.Header == nil {
+		l.Header = new(LightClientHeaderAltair)
+	}
+	if dst, err = l.Header.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if l.CurrentSyncCommittee == nil {
+		l.CurrentSyncCommittee = new(SyncCommittee)
+	}
+	if dst, err = l.CurrentSyncCommittee.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	if size := len(l.CurrentSyncCommitteeBranch); size != 5 {
+		err = ssz.ErrVectorLengthFn("--.CurrentSyncCommitteeBranch", size, 5)
+		return
+	}
+	for ii := 0; ii < 5; ii++ {
+		if size := len(l.CurrentSyncCommitteeBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.CurrentSyncCommitteeBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.CurrentSyncCommitteeBranch[ii]...)
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientBootstrapAltair object
+func (l *LightClientBootstrapAltair) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size != 24896 {
+		return ssz.ErrSize
+	}
+
+	// Field (0) 'Header'
+	if l.Header == nil {
+		l.Header = new(LightClientHeaderAltair)
+	}
+	if err = l.Header.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if l.CurrentSyncCommittee == nil {
+		l.CurrentSyncCommittee = new(SyncCommittee)
+	}
+	if err = l.CurrentSyncCommittee.UnmarshalSSZ(buf[112:24736]); err != nil {
+		return err
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	l.CurrentSyncCommitteeBranch = make([][]byte, 5)
+	for ii := 0; ii < 5; ii++ {
+		if cap(l.CurrentSyncCommitteeBranch[ii]) == 0 {
+			l.CurrentSyncCommitteeBranch[ii] = make([]byte, 0, len(buf[24736:24896][ii*32:(ii+1)*32]))
+		}
+		l.CurrentSyncCommitteeBranch[ii] = append(l.CurrentSyncCommitteeBranch[ii], buf[24736:24896][ii*32:(ii+1)*32]...)
+	}
+
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientBootstrapAltair object
+func (l *LightClientBootstrapAltair) SizeSSZ() (size int) {
+	size = 24896
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientBootstrapAltair object
+func (l *LightClientBootstrapAltair) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientBootstrapAltair object with a hasher
+func (l *LightClientBootstrapAltair) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Header'
+	if err = l.Header.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if err = l.CurrentSyncCommittee.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	{
+		if size := len(l.CurrentSyncCommitteeBranch); size != 5 {
+			err = ssz.ErrVectorLengthFn("--.CurrentSyncCommitteeBranch", size, 5)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.CurrentSyncCommitteeBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientUpdateAltair object
+func (l *LightClientUpdateAltair) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientUpdateAltair object to a target array
+func (l *LightClientUpdateAltair) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderAltair)
+	}
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if l.NextSyncCommittee == nil {
+		l.NextSyncCommittee = new(SyncCommittee)
+	}
+	if dst, err = l.NextSyncCommittee.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	if size := len(l.NextSyncCommitteeBranch); size != 5 {
+		err = ssz.ErrVectorLengthFn("--.NextSyncCommitteeBranch", size, 5)
+		return
+	}
+	for ii := 0; ii < 5; ii++ {
+		if size := len(l.NextSyncCommitteeBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.NextSyncCommitteeBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.NextSyncCommitteeBranch[ii]...)
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderAltair)
+	}
+	if dst, err = l.FinalizedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (4) 'FinalityBranch'
+	if size := len(l.FinalityBranch); size != 6 {
+		err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+		return
+	}
+	for ii := 0; ii < 6; ii++ {
+		if size := len(l.FinalityBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.FinalityBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.FinalityBranch[ii]...)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (6) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientUpdateAltair object
+func (l *LightClientUpdateAltair) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size != 25368 {
+		return ssz.ErrSize
+	}
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderAltair)
+	}
+	if err = l.AttestedHeader.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if l.NextSyncCommittee == nil {
+		l.NextSyncCommittee = new(SyncCommittee)
+	}
+	if err = l.NextSyncCommittee.UnmarshalSSZ(buf[112:24736]); err != nil {
+		return err
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	l.NextSyncCommitteeBranch = make([][]byte, 5)
+	for ii := 0; ii < 5; ii++ {
+		if cap(l.NextSyncCommitteeBranch[ii]) == 0 {
+			l.NextSyncCommitteeBranch[ii] = make([]byte, 0, len(buf[24736:24896][ii*32:(ii+1)*32]))
+		}
+		l.NextSyncCommitteeBranch[ii] = append(l.NextSyncCommitteeBranch[ii], buf[24736:24896][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderAltair)
+	}
+	if err = l.FinalizedHeader.UnmarshalSSZ(buf[24896:25008]); err != nil {
+		return err
+	}
+
+	// Field (4) 'FinalityBranch'
+	l.FinalityBranch = make([][]byte, 6)
+	for ii := 0; ii < 6; ii++ {
+		if cap(l.FinalityBranch[ii]) == 0 {
+			l.FinalityBranch[ii] = make([]byte, 0, len(buf[25008:25200][ii*32:(ii+1)*32]))
+		}
+		l.FinalityBranch[ii] = append(l.FinalityBranch[ii], buf[25008:25200][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[25200:25360]); err != nil {
+		return err
+	}
+
+	// Field (6) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[25360:25368]))
+
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientUpdateAltair object
+func (l *LightClientUpdateAltair) SizeSSZ() (size int) {
+	size = 25368
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientUpdateAltair object
+func (l *LightClientUpdateAltair) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientUpdateAltair object with a hasher
+func (l *LightClientUpdateAltair) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if err = l.NextSyncCommittee.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	{
+		if size := len(l.NextSyncCommitteeBranch); size != 5 {
+			err = ssz.ErrVectorLengthFn("--.NextSyncCommitteeBranch", size, 5)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.NextSyncCommitteeBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if err = l.FinalizedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (4) 'FinalityBranch'
+	{
+		if size := len(l.FinalityBranch); size != 6 {
+			err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.FinalityBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (6) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientFinalityUpdateAltair object
+func (l *LightClientFinalityUpdateAltair) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientFinalityUpdateAltair object to a target array
+func (l *LightClientFinalityUpdateAltair) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderAltair)
+	}
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderAltair)
+	}
+	if dst, err = l.FinalizedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'FinalityBranch'
+	if size := len(l.FinalityBranch); size != 6 {
+		err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+		return
+	}
+	for ii := 0; ii < 6; ii++ {
+		if size := len(l.FinalityBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.FinalityBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.FinalityBranch[ii]...)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (4) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientFinalityUpdateAltair object
+func (l *LightClientFinalityUpdateAltair) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size != 584 {
+		return ssz.ErrSize
+	}
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderAltair)
+	}
+	if err = l.AttestedHeader.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderAltair)
+	}
+	if err = l.FinalizedHeader.UnmarshalSSZ(buf[112:224]); err != nil {
+		return err
+	}
+
+	// Field (2) 'FinalityBranch'
+	l.FinalityBranch = make([][]byte, 6)
+	for ii := 0; ii < 6; ii++ {
+		if cap(l.FinalityBranch[ii]) == 0 {
+			l.FinalityBranch[ii] = make([]byte, 0, len(buf[224:416][ii*32:(ii+1)*32]))
+		}
+		l.FinalityBranch[ii] = append(l.FinalityBranch[ii], buf[224:416][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[416:576]); err != nil {
+		return err
+	}
+
+	// Field (4) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[576:584]))
+
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientFinalityUpdateAltair object
+func (l *LightClientFinalityUpdateAltair) SizeSSZ() (size int) {
+	size = 584
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientFinalityUpdateAltair object
+func (l *LightClientFinalityUpdateAltair) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientFinalityUpdateAltair object with a hasher
+func (l *LightClientFinalityUpdateAltair) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if err = l.FinalizedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'FinalityBranch'
+	{
+		if size := len(l.FinalityBranch); size != 6 {
+			err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.FinalityBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (4) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientOptimisticUpdateAltair object
+func (l *LightClientOptimisticUpdateAltair) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientOptimisticUpdateAltair object to a target array
+func (l *LightClientOptimisticUpdateAltair) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderAltair)
+	}
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientOptimisticUpdateAltair object
+func (l *LightClientOptimisticUpdateAltair) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size != 280 {
+		return ssz.ErrSize
+	}
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderAltair)
+	}
+	if err = l.AttestedHeader.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	// Field (1) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[112:272]); err != nil {
+		return err
+	}
+
+	// Field (2) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[272:280]))
+
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientOptimisticUpdateAltair object
+func (l *LightClientOptimisticUpdateAltair) SizeSSZ() (size int) {
+	size = 280
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientOptimisticUpdateAltair object
+func (l *LightClientOptimisticUpdateAltair) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientOptimisticUpdateAltair object with a hasher
+func (l *LightClientOptimisticUpdateAltair) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
 // MarshalSSZ ssz marshals the SyncCommitteeMessage object
 func (s *SyncCommitteeMessage) MarshalSSZ() ([]byte, error) {
 	return ssz.MarshalSSZ(s)

proto/prysm/v1alpha1/bellatrix.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: 693cad07de8560b2681132d912aebb927e668fe15e5cb9f42e8a36bbac6e2c5e
+// Hash: c6614861443f105e2d5445ca29187cc78c2a929161d0a15b36ce2f0e6517a0ea
 package eth
 
 import (

proto/prysm/v1alpha1/capella.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: a5507ef7d71897486989f37eb4dbb19fc2c49e7c47f244291a9f3122c9bfe546
+// Hash: 6bee0cf7c5707af68be518a221b248ce37edd4b0b1e6fec9703c6152a5107a1d
 package eth
 
 import (
@@ -2729,6 +2729,877 @@ func (h *HistoricalSummary) HashTreeRootWith(hh *ssz.Hasher) (err error) {
 	return
 }
 
+// MarshalSSZ ssz marshals the LightClientHeaderCapella object
+func (l *LightClientHeaderCapella) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientHeaderCapella object to a target array
+func (l *LightClientHeaderCapella) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(244)
+
+	// Field (0) 'Beacon'
+	if l.Beacon == nil {
+		l.Beacon = new(BeaconBlockHeader)
+	}
+	if dst, err = l.Beacon.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Offset (1) 'Execution'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.Execution == nil {
+		l.Execution = new(v1.ExecutionPayloadHeaderCapella)
+	}
+	offset += l.Execution.SizeSSZ()
+
+	// Field (2) 'ExecutionBranch'
+	if size := len(l.ExecutionBranch); size != 4 {
+		err = ssz.ErrVectorLengthFn("--.ExecutionBranch", size, 4)
+		return
+	}
+	for ii := 0; ii < 4; ii++ {
+		if size := len(l.ExecutionBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.ExecutionBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.ExecutionBranch[ii]...)
+	}
+
+	// Field (1) 'Execution'
+	if dst, err = l.Execution.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientHeaderCapella object
+func (l *LightClientHeaderCapella) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 244 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o1 uint64
+
+	// Field (0) 'Beacon'
+	if l.Beacon == nil {
+		l.Beacon = new(BeaconBlockHeader)
+	}
+	if err = l.Beacon.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	// Offset (1) 'Execution'
+	if o1 = ssz.ReadOffset(buf[112:116]); o1 > size {
+		return ssz.ErrOffset
+	}
+
+	if o1 != 244 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (2) 'ExecutionBranch'
+	l.ExecutionBranch = make([][]byte, 4)
+	for ii := 0; ii < 4; ii++ {
+		if cap(l.ExecutionBranch[ii]) == 0 {
+			l.ExecutionBranch[ii] = make([]byte, 0, len(buf[116:244][ii*32:(ii+1)*32]))
+		}
+		l.ExecutionBranch[ii] = append(l.ExecutionBranch[ii], buf[116:244][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (1) 'Execution'
+	{
+		buf = tail[o1:]
+		if l.Execution == nil {
+			l.Execution = new(v1.ExecutionPayloadHeaderCapella)
+		}
+		if err = l.Execution.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientHeaderCapella object
+func (l *LightClientHeaderCapella) SizeSSZ() (size int) {
+	size = 244
+
+	// Field (1) 'Execution'
+	if l.Execution == nil {
+		l.Execution = new(v1.ExecutionPayloadHeaderCapella)
+	}
+	size += l.Execution.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientHeaderCapella object
+func (l *LightClientHeaderCapella) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientHeaderCapella object with a hasher
+func (l *LightClientHeaderCapella) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Beacon'
+	if err = l.Beacon.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'Execution'
+	if err = l.Execution.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'ExecutionBranch'
+	{
+		if size := len(l.ExecutionBranch); size != 4 {
+			err = ssz.ErrVectorLengthFn("--.ExecutionBranch", size, 4)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.ExecutionBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientBootstrapCapella object
+func (l *LightClientBootstrapCapella) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientBootstrapCapella object to a target array
+func (l *LightClientBootstrapCapella) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(24788)
+
+	// Offset (0) 'Header'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.Header == nil {
+		l.Header = new(LightClientHeaderCapella)
+	}
+	offset += l.Header.SizeSSZ()
+
+	// Field (1) 'CurrentSyncCommittee'
+	if l.CurrentSyncCommittee == nil {
+		l.CurrentSyncCommittee = new(SyncCommittee)
+	}
+	if dst, err = l.CurrentSyncCommittee.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	if size := len(l.CurrentSyncCommitteeBranch); size != 5 {
+		err = ssz.ErrVectorLengthFn("--.CurrentSyncCommitteeBranch", size, 5)
+		return
+	}
+	for ii := 0; ii < 5; ii++ {
+		if size := len(l.CurrentSyncCommitteeBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.CurrentSyncCommitteeBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.CurrentSyncCommitteeBranch[ii]...)
+	}
+
+	// Field (0) 'Header'
+	if dst, err = l.Header.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientBootstrapCapella object
+func (l *LightClientBootstrapCapella) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 24788 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0 uint64
+
+	// Offset (0) 'Header'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 24788 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if l.CurrentSyncCommittee == nil {
+		l.CurrentSyncCommittee = new(SyncCommittee)
+	}
+	if err = l.CurrentSyncCommittee.UnmarshalSSZ(buf[4:24628]); err != nil {
+		return err
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	l.CurrentSyncCommitteeBranch = make([][]byte, 5)
+	for ii := 0; ii < 5; ii++ {
+		if cap(l.CurrentSyncCommitteeBranch[ii]) == 0 {
+			l.CurrentSyncCommitteeBranch[ii] = make([]byte, 0, len(buf[24628:24788][ii*32:(ii+1)*32]))
+		}
+		l.CurrentSyncCommitteeBranch[ii] = append(l.CurrentSyncCommitteeBranch[ii], buf[24628:24788][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (0) 'Header'
+	{
+		buf = tail[o0:]
+		if l.Header == nil {
+			l.Header = new(LightClientHeaderCapella)
+		}
+		if err = l.Header.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientBootstrapCapella object
+func (l *LightClientBootstrapCapella) SizeSSZ() (size int) {
+	size = 24788
+
+	// Field (0) 'Header'
+	if l.Header == nil {
+		l.Header = new(LightClientHeaderCapella)
+	}
+	size += l.Header.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientBootstrapCapella object
+func (l *LightClientBootstrapCapella) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientBootstrapCapella object with a hasher
+func (l *LightClientBootstrapCapella) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Header'
+	if err = l.Header.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if err = l.CurrentSyncCommittee.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	{
+		if size := len(l.CurrentSyncCommitteeBranch); size != 5 {
+			err = ssz.ErrVectorLengthFn("--.CurrentSyncCommitteeBranch", size, 5)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.CurrentSyncCommitteeBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientUpdateCapella object
+func (l *LightClientUpdateCapella) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientUpdateCapella object to a target array
+func (l *LightClientUpdateCapella) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(25152)
+
+	// Offset (0) 'AttestedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderCapella)
+	}
+	offset += l.AttestedHeader.SizeSSZ()
+
+	// Field (1) 'NextSyncCommittee'
+	if l.NextSyncCommittee == nil {
+		l.NextSyncCommittee = new(SyncCommittee)
+	}
+	if dst, err = l.NextSyncCommittee.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	if size := len(l.NextSyncCommitteeBranch); size != 5 {
+		err = ssz.ErrVectorLengthFn("--.NextSyncCommitteeBranch", size, 5)
+		return
+	}
+	for ii := 0; ii < 5; ii++ {
+		if size := len(l.NextSyncCommitteeBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.NextSyncCommitteeBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.NextSyncCommitteeBranch[ii]...)
+	}
+
+	// Offset (3) 'FinalizedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderCapella)
+	}
+	offset += l.FinalizedHeader.SizeSSZ()
+
+	// Field (4) 'FinalityBranch'
+	if size := len(l.FinalityBranch); size != 6 {
+		err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+		return
+	}
+	for ii := 0; ii < 6; ii++ {
+		if size := len(l.FinalityBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.FinalityBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.FinalityBranch[ii]...)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (6) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	// Field (0) 'AttestedHeader'
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if dst, err = l.FinalizedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientUpdateCapella object
+func (l *LightClientUpdateCapella) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 25152 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0, o3 uint64
+
+	// Offset (0) 'AttestedHeader'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 25152 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if l.NextSyncCommittee == nil {
+		l.NextSyncCommittee = new(SyncCommittee)
+	}
+	if err = l.NextSyncCommittee.UnmarshalSSZ(buf[4:24628]); err != nil {
+		return err
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	l.NextSyncCommitteeBranch = make([][]byte, 5)
+	for ii := 0; ii < 5; ii++ {
+		if cap(l.NextSyncCommitteeBranch[ii]) == 0 {
+			l.NextSyncCommitteeBranch[ii] = make([]byte, 0, len(buf[24628:24788][ii*32:(ii+1)*32]))
+		}
+		l.NextSyncCommitteeBranch[ii] = append(l.NextSyncCommitteeBranch[ii], buf[24628:24788][ii*32:(ii+1)*32]...)
+	}
+
+	// Offset (3) 'FinalizedHeader'
+	if o3 = ssz.ReadOffset(buf[24788:24792]); o3 > size || o0 > o3 {
+		return ssz.ErrOffset
+	}
+
+	// Field (4) 'FinalityBranch'
+	l.FinalityBranch = make([][]byte, 6)
+	for ii := 0; ii < 6; ii++ {
+		if cap(l.FinalityBranch[ii]) == 0 {
+			l.FinalityBranch[ii] = make([]byte, 0, len(buf[24792:24984][ii*32:(ii+1)*32]))
+		}
+		l.FinalityBranch[ii] = append(l.FinalityBranch[ii], buf[24792:24984][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[24984:25144]); err != nil {
+		return err
+	}
+
+	// Field (6) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[25144:25152]))
+
+	// Field (0) 'AttestedHeader'
+	{
+		buf = tail[o0:o3]
+		if l.AttestedHeader == nil {
+			l.AttestedHeader = new(LightClientHeaderCapella)
+		}
+		if err = l.AttestedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+
+	// Field (3) 'FinalizedHeader'
+	{
+		buf = tail[o3:]
+		if l.FinalizedHeader == nil {
+			l.FinalizedHeader = new(LightClientHeaderCapella)
+		}
+		if err = l.FinalizedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientUpdateCapella object
+func (l *LightClientUpdateCapella) SizeSSZ() (size int) {
+	size = 25152
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderCapella)
+	}
+	size += l.AttestedHeader.SizeSSZ()
+
+	// Field (3) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderCapella)
+	}
+	size += l.FinalizedHeader.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientUpdateCapella object
+func (l *LightClientUpdateCapella) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientUpdateCapella object with a hasher
+func (l *LightClientUpdateCapella) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if err = l.NextSyncCommittee.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	{
+		if size := len(l.NextSyncCommitteeBranch); size != 5 {
+			err = ssz.ErrVectorLengthFn("--.NextSyncCommitteeBranch", size, 5)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.NextSyncCommitteeBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if err = l.FinalizedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (4) 'FinalityBranch'
+	{
+		if size := len(l.FinalityBranch); size != 6 {
+			err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.FinalityBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (6) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientFinalityUpdateCapella object
+func (l *LightClientFinalityUpdateCapella) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientFinalityUpdateCapella object to a target array
+func (l *LightClientFinalityUpdateCapella) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(368)
+
+	// Offset (0) 'AttestedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderCapella)
+	}
+	offset += l.AttestedHeader.SizeSSZ()
+
+	// Offset (1) 'FinalizedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderCapella)
+	}
+	offset += l.FinalizedHeader.SizeSSZ()
+
+	// Field (2) 'FinalityBranch'
+	if size := len(l.FinalityBranch); size != 6 {
+		err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+		return
+	}
+	for ii := 0; ii < 6; ii++ {
+		if size := len(l.FinalityBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.FinalityBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.FinalityBranch[ii]...)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (4) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	// Field (0) 'AttestedHeader'
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if dst, err = l.FinalizedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientFinalityUpdateCapella object
+func (l *LightClientFinalityUpdateCapella) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 368 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0, o1 uint64
+
+	// Offset (0) 'AttestedHeader'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 368 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Offset (1) 'FinalizedHeader'
+	if o1 = ssz.ReadOffset(buf[4:8]); o1 > size || o0 > o1 {
+		return ssz.ErrOffset
+	}
+
+	// Field (2) 'FinalityBranch'
+	l.FinalityBranch = make([][]byte, 6)
+	for ii := 0; ii < 6; ii++ {
+		if cap(l.FinalityBranch[ii]) == 0 {
+			l.FinalityBranch[ii] = make([]byte, 0, len(buf[8:200][ii*32:(ii+1)*32]))
+		}
+		l.FinalityBranch[ii] = append(l.FinalityBranch[ii], buf[8:200][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[200:360]); err != nil {
+		return err
+	}
+
+	// Field (4) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[360:368]))
+
+	// Field (0) 'AttestedHeader'
+	{
+		buf = tail[o0:o1]
+		if l.AttestedHeader == nil {
+			l.AttestedHeader = new(LightClientHeaderCapella)
+		}
+		if err = l.AttestedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+
+	// Field (1) 'FinalizedHeader'
+	{
+		buf = tail[o1:]
+		if l.FinalizedHeader == nil {
+			l.FinalizedHeader = new(LightClientHeaderCapella)
+		}
+		if err = l.FinalizedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientFinalityUpdateCapella object
+func (l *LightClientFinalityUpdateCapella) SizeSSZ() (size int) {
+	size = 368
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderCapella)
+	}
+	size += l.AttestedHeader.SizeSSZ()
+
+	// Field (1) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderCapella)
+	}
+	size += l.FinalizedHeader.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientFinalityUpdateCapella object
+func (l *LightClientFinalityUpdateCapella) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientFinalityUpdateCapella object with a hasher
+func (l *LightClientFinalityUpdateCapella) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if err = l.FinalizedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'FinalityBranch'
+	{
+		if size := len(l.FinalityBranch); size != 6 {
+			err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.FinalityBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (4) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientOptimisticUpdateCapella object
+func (l *LightClientOptimisticUpdateCapella) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientOptimisticUpdateCapella object to a target array
+func (l *LightClientOptimisticUpdateCapella) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(172)
+
+	// Offset (0) 'AttestedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderCapella)
+	}
+	offset += l.AttestedHeader.SizeSSZ()
+
+	// Field (1) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	// Field (0) 'AttestedHeader'
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientOptimisticUpdateCapella object
+func (l *LightClientOptimisticUpdateCapella) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 172 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0 uint64
+
+	// Offset (0) 'AttestedHeader'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 172 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (1) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[4:164]); err != nil {
+		return err
+	}
+
+	// Field (2) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[164:172]))
+
+	// Field (0) 'AttestedHeader'
+	{
+		buf = tail[o0:]
+		if l.AttestedHeader == nil {
+			l.AttestedHeader = new(LightClientHeaderCapella)
+		}
+		if err = l.AttestedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientOptimisticUpdateCapella object
+func (l *LightClientOptimisticUpdateCapella) SizeSSZ() (size int) {
+	size = 172
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderCapella)
+	}
+	size += l.AttestedHeader.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientOptimisticUpdateCapella object
+func (l *LightClientOptimisticUpdateCapella) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientOptimisticUpdateCapella object with a hasher
+func (l *LightClientOptimisticUpdateCapella) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
 // MarshalSSZ ssz marshals the BLSToExecutionChange object
 func (b *BLSToExecutionChange) MarshalSSZ() ([]byte, error) {
 	return ssz.MarshalSSZ(b)

proto/prysm/v1alpha1/deneb.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: 4c3e6932bf84838e8de21e5c121c14d03cbccb051c3990d3b924932f531f4d30
+// Hash: dc56f26fb2603482588d88426187e889583abce2eeb7556ac0dc1ebaa891c455
 package eth
 
 import (
@@ -3593,3 +3593,874 @@ func (b *BlobIdentifier) HashTreeRootWith(hh *ssz.Hasher) (err error) {
 	hh.Merkleize(indx)
 	return
 }
+
+// MarshalSSZ ssz marshals the LightClientHeaderDeneb object
+func (l *LightClientHeaderDeneb) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientHeaderDeneb object to a target array
+func (l *LightClientHeaderDeneb) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(244)
+
+	// Field (0) 'Beacon'
+	if l.Beacon == nil {
+		l.Beacon = new(BeaconBlockHeader)
+	}
+	if dst, err = l.Beacon.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Offset (1) 'Execution'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.Execution == nil {
+		l.Execution = new(v1.ExecutionPayloadHeaderDeneb)
+	}
+	offset += l.Execution.SizeSSZ()
+
+	// Field (2) 'ExecutionBranch'
+	if size := len(l.ExecutionBranch); size != 4 {
+		err = ssz.ErrVectorLengthFn("--.ExecutionBranch", size, 4)
+		return
+	}
+	for ii := 0; ii < 4; ii++ {
+		if size := len(l.ExecutionBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.ExecutionBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.ExecutionBranch[ii]...)
+	}
+
+	// Field (1) 'Execution'
+	if dst, err = l.Execution.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientHeaderDeneb object
+func (l *LightClientHeaderDeneb) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 244 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o1 uint64
+
+	// Field (0) 'Beacon'
+	if l.Beacon == nil {
+		l.Beacon = new(BeaconBlockHeader)
+	}
+	if err = l.Beacon.UnmarshalSSZ(buf[0:112]); err != nil {
+		return err
+	}
+
+	// Offset (1) 'Execution'
+	if o1 = ssz.ReadOffset(buf[112:116]); o1 > size {
+		return ssz.ErrOffset
+	}
+
+	if o1 != 244 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (2) 'ExecutionBranch'
+	l.ExecutionBranch = make([][]byte, 4)
+	for ii := 0; ii < 4; ii++ {
+		if cap(l.ExecutionBranch[ii]) == 0 {
+			l.ExecutionBranch[ii] = make([]byte, 0, len(buf[116:244][ii*32:(ii+1)*32]))
+		}
+		l.ExecutionBranch[ii] = append(l.ExecutionBranch[ii], buf[116:244][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (1) 'Execution'
+	{
+		buf = tail[o1:]
+		if l.Execution == nil {
+			l.Execution = new(v1.ExecutionPayloadHeaderDeneb)
+		}
+		if err = l.Execution.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientHeaderDeneb object
+func (l *LightClientHeaderDeneb) SizeSSZ() (size int) {
+	size = 244
+
+	// Field (1) 'Execution'
+	if l.Execution == nil {
+		l.Execution = new(v1.ExecutionPayloadHeaderDeneb)
+	}
+	size += l.Execution.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientHeaderDeneb object
+func (l *LightClientHeaderDeneb) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientHeaderDeneb object with a hasher
+func (l *LightClientHeaderDeneb) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Beacon'
+	if err = l.Beacon.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'Execution'
+	if err = l.Execution.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'ExecutionBranch'
+	{
+		if size := len(l.ExecutionBranch); size != 4 {
+			err = ssz.ErrVectorLengthFn("--.ExecutionBranch", size, 4)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.ExecutionBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientBootstrapDeneb object
+func (l *LightClientBootstrapDeneb) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientBootstrapDeneb object to a target array
+func (l *LightClientBootstrapDeneb) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(24788)
+
+	// Offset (0) 'Header'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.Header == nil {
+		l.Header = new(LightClientHeaderDeneb)
+	}
+	offset += l.Header.SizeSSZ()
+
+	// Field (1) 'CurrentSyncCommittee'
+	if l.CurrentSyncCommittee == nil {
+		l.CurrentSyncCommittee = new(SyncCommittee)
+	}
+	if dst, err = l.CurrentSyncCommittee.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	if size := len(l.CurrentSyncCommitteeBranch); size != 5 {
+		err = ssz.ErrVectorLengthFn("--.CurrentSyncCommitteeBranch", size, 5)
+		return
+	}
+	for ii := 0; ii < 5; ii++ {
+		if size := len(l.CurrentSyncCommitteeBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.CurrentSyncCommitteeBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.CurrentSyncCommitteeBranch[ii]...)
+	}
+
+	// Field (0) 'Header'
+	if dst, err = l.Header.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientBootstrapDeneb object
+func (l *LightClientBootstrapDeneb) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 24788 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0 uint64
+
+	// Offset (0) 'Header'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 24788 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if l.CurrentSyncCommittee == nil {
+		l.CurrentSyncCommittee = new(SyncCommittee)
+	}
+	if err = l.CurrentSyncCommittee.UnmarshalSSZ(buf[4:24628]); err != nil {
+		return err
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	l.CurrentSyncCommitteeBranch = make([][]byte, 5)
+	for ii := 0; ii < 5; ii++ {
+		if cap(l.CurrentSyncCommitteeBranch[ii]) == 0 {
+			l.CurrentSyncCommitteeBranch[ii] = make([]byte, 0, len(buf[24628:24788][ii*32:(ii+1)*32]))
+		}
+		l.CurrentSyncCommitteeBranch[ii] = append(l.CurrentSyncCommitteeBranch[ii], buf[24628:24788][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (0) 'Header'
+	{
+		buf = tail[o0:]
+		if l.Header == nil {
+			l.Header = new(LightClientHeaderDeneb)
+		}
+		if err = l.Header.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientBootstrapDeneb object
+func (l *LightClientBootstrapDeneb) SizeSSZ() (size int) {
+	size = 24788
+
+	// Field (0) 'Header'
+	if l.Header == nil {
+		l.Header = new(LightClientHeaderDeneb)
+	}
+	size += l.Header.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientBootstrapDeneb object
+func (l *LightClientBootstrapDeneb) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientBootstrapDeneb object with a hasher
+func (l *LightClientBootstrapDeneb) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Header'
+	if err = l.Header.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'CurrentSyncCommittee'
+	if err = l.CurrentSyncCommittee.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'CurrentSyncCommitteeBranch'
+	{
+		if size := len(l.CurrentSyncCommitteeBranch); size != 5 {
+			err = ssz.ErrVectorLengthFn("--.CurrentSyncCommitteeBranch", size, 5)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.CurrentSyncCommitteeBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientUpdateDeneb object
+func (l *LightClientUpdateDeneb) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientUpdateDeneb object to a target array
+func (l *LightClientUpdateDeneb) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(25152)
+
+	// Offset (0) 'AttestedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderDeneb)
+	}
+	offset += l.AttestedHeader.SizeSSZ()
+
+	// Field (1) 'NextSyncCommittee'
+	if l.NextSyncCommittee == nil {
+		l.NextSyncCommittee = new(SyncCommittee)
+	}
+	if dst, err = l.NextSyncCommittee.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	if size := len(l.NextSyncCommitteeBranch); size != 5 {
+		err = ssz.ErrVectorLengthFn("--.NextSyncCommitteeBranch", size, 5)
+		return
+	}
+	for ii := 0; ii < 5; ii++ {
+		if size := len(l.NextSyncCommitteeBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.NextSyncCommitteeBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.NextSyncCommitteeBranch[ii]...)
+	}
+
+	// Offset (3) 'FinalizedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderDeneb)
+	}
+	offset += l.FinalizedHeader.SizeSSZ()
+
+	// Field (4) 'FinalityBranch'
+	if size := len(l.FinalityBranch); size != 6 {
+		err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+		return
+	}
+	for ii := 0; ii < 6; ii++ {
+		if size := len(l.FinalityBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.FinalityBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.FinalityBranch[ii]...)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (6) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	// Field (0) 'AttestedHeader'
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if dst, err = l.FinalizedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientUpdateDeneb object
+func (l *LightClientUpdateDeneb) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 25152 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0, o3 uint64
+
+	// Offset (0) 'AttestedHeader'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 25152 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if l.NextSyncCommittee == nil {
+		l.NextSyncCommittee = new(SyncCommittee)
+	}
+	if err = l.NextSyncCommittee.UnmarshalSSZ(buf[4:24628]); err != nil {
+		return err
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	l.NextSyncCommitteeBranch = make([][]byte, 5)
+	for ii := 0; ii < 5; ii++ {
+		if cap(l.NextSyncCommitteeBranch[ii]) == 0 {
+			l.NextSyncCommitteeBranch[ii] = make([]byte, 0, len(buf[24628:24788][ii*32:(ii+1)*32]))
+		}
+		l.NextSyncCommitteeBranch[ii] = append(l.NextSyncCommitteeBranch[ii], buf[24628:24788][ii*32:(ii+1)*32]...)
+	}
+
+	// Offset (3) 'FinalizedHeader'
+	if o3 = ssz.ReadOffset(buf[24788:24792]); o3 > size || o0 > o3 {
+		return ssz.ErrOffset
+	}
+
+	// Field (4) 'FinalityBranch'
+	l.FinalityBranch = make([][]byte, 6)
+	for ii := 0; ii < 6; ii++ {
+		if cap(l.FinalityBranch[ii]) == 0 {
+			l.FinalityBranch[ii] = make([]byte, 0, len(buf[24792:24984][ii*32:(ii+1)*32]))
+		}
+		l.FinalityBranch[ii] = append(l.FinalityBranch[ii], buf[24792:24984][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[24984:25144]); err != nil {
+		return err
+	}
+
+	// Field (6) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[25144:25152]))
+
+	// Field (0) 'AttestedHeader'
+	{
+		buf = tail[o0:o3]
+		if l.AttestedHeader == nil {
+			l.AttestedHeader = new(LightClientHeaderDeneb)
+		}
+		if err = l.AttestedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+
+	// Field (3) 'FinalizedHeader'
+	{
+		buf = tail[o3:]
+		if l.FinalizedHeader == nil {
+			l.FinalizedHeader = new(LightClientHeaderDeneb)
+		}
+		if err = l.FinalizedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientUpdateDeneb object
+func (l *LightClientUpdateDeneb) SizeSSZ() (size int) {
+	size = 25152
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderDeneb)
+	}
+	size += l.AttestedHeader.SizeSSZ()
+
+	// Field (3) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderDeneb)
+	}
+	size += l.FinalizedHeader.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientUpdateDeneb object
+func (l *LightClientUpdateDeneb) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientUpdateDeneb object with a hasher
+func (l *LightClientUpdateDeneb) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'NextSyncCommittee'
+	if err = l.NextSyncCommittee.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'NextSyncCommitteeBranch'
+	{
+		if size := len(l.NextSyncCommitteeBranch); size != 5 {
+			err = ssz.ErrVectorLengthFn("--.NextSyncCommitteeBranch", size, 5)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.NextSyncCommitteeBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (3) 'FinalizedHeader'
+	if err = l.FinalizedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (4) 'FinalityBranch'
+	{
+		if size := len(l.FinalityBranch); size != 6 {
+			err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.FinalityBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (5) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (6) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientFinalityUpdateDeneb object
+func (l *LightClientFinalityUpdateDeneb) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientFinalityUpdateDeneb object to a target array
+func (l *LightClientFinalityUpdateDeneb) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(368)
+
+	// Offset (0) 'AttestedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderDeneb)
+	}
+	offset += l.AttestedHeader.SizeSSZ()
+
+	// Offset (1) 'FinalizedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderDeneb)
+	}
+	offset += l.FinalizedHeader.SizeSSZ()
+
+	// Field (2) 'FinalityBranch'
+	if size := len(l.FinalityBranch); size != 6 {
+		err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+		return
+	}
+	for ii := 0; ii < 6; ii++ {
+		if size := len(l.FinalityBranch[ii]); size != 32 {
+			err = ssz.ErrBytesLengthFn("--.FinalityBranch[ii]", size, 32)
+			return
+		}
+		dst = append(dst, l.FinalityBranch[ii]...)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (4) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	// Field (0) 'AttestedHeader'
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if dst, err = l.FinalizedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientFinalityUpdateDeneb object
+func (l *LightClientFinalityUpdateDeneb) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 368 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0, o1 uint64
+
+	// Offset (0) 'AttestedHeader'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 368 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Offset (1) 'FinalizedHeader'
+	if o1 = ssz.ReadOffset(buf[4:8]); o1 > size || o0 > o1 {
+		return ssz.ErrOffset
+	}
+
+	// Field (2) 'FinalityBranch'
+	l.FinalityBranch = make([][]byte, 6)
+	for ii := 0; ii < 6; ii++ {
+		if cap(l.FinalityBranch[ii]) == 0 {
+			l.FinalityBranch[ii] = make([]byte, 0, len(buf[8:200][ii*32:(ii+1)*32]))
+		}
+		l.FinalityBranch[ii] = append(l.FinalityBranch[ii], buf[8:200][ii*32:(ii+1)*32]...)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[200:360]); err != nil {
+		return err
+	}
+
+	// Field (4) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[360:368]))
+
+	// Field (0) 'AttestedHeader'
+	{
+		buf = tail[o0:o1]
+		if l.AttestedHeader == nil {
+			l.AttestedHeader = new(LightClientHeaderDeneb)
+		}
+		if err = l.AttestedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+
+	// Field (1) 'FinalizedHeader'
+	{
+		buf = tail[o1:]
+		if l.FinalizedHeader == nil {
+			l.FinalizedHeader = new(LightClientHeaderDeneb)
+		}
+		if err = l.FinalizedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientFinalityUpdateDeneb object
+func (l *LightClientFinalityUpdateDeneb) SizeSSZ() (size int) {
+	size = 368
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderDeneb)
+	}
+	size += l.AttestedHeader.SizeSSZ()
+
+	// Field (1) 'FinalizedHeader'
+	if l.FinalizedHeader == nil {
+		l.FinalizedHeader = new(LightClientHeaderDeneb)
+	}
+	size += l.FinalizedHeader.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientFinalityUpdateDeneb object
+func (l *LightClientFinalityUpdateDeneb) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientFinalityUpdateDeneb object with a hasher
+func (l *LightClientFinalityUpdateDeneb) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'FinalizedHeader'
+	if err = l.FinalizedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'FinalityBranch'
+	{
+		if size := len(l.FinalityBranch); size != 6 {
+			err = ssz.ErrVectorLengthFn("--.FinalityBranch", size, 6)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range l.FinalityBranch {
+			if len(i) != 32 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.Append(i)
+		}
+		hh.Merkleize(subIndx)
+	}
+
+	// Field (3) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (4) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}
+
+// MarshalSSZ ssz marshals the LightClientOptimisticUpdateDeneb object
+func (l *LightClientOptimisticUpdateDeneb) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(l)
+}
+
+// MarshalSSZTo ssz marshals the LightClientOptimisticUpdateDeneb object to a target array
+func (l *LightClientOptimisticUpdateDeneb) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(172)
+
+	// Offset (0) 'AttestedHeader'
+	dst = ssz.WriteOffset(dst, offset)
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderDeneb)
+	}
+	offset += l.AttestedHeader.SizeSSZ()
+
+	// Field (1) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if dst, err = l.SyncAggregate.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (2) 'SignatureSlot'
+	dst = ssz.MarshalUint64(dst, uint64(l.SignatureSlot))
+
+	// Field (0) 'AttestedHeader'
+	if dst, err = l.AttestedHeader.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the LightClientOptimisticUpdateDeneb object
+func (l *LightClientOptimisticUpdateDeneb) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 172 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0 uint64
+
+	// Offset (0) 'AttestedHeader'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 172 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Field (1) 'SyncAggregate'
+	if l.SyncAggregate == nil {
+		l.SyncAggregate = new(SyncAggregate)
+	}
+	if err = l.SyncAggregate.UnmarshalSSZ(buf[4:164]); err != nil {
+		return err
+	}
+
+	// Field (2) 'SignatureSlot'
+	l.SignatureSlot = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Slot(ssz.UnmarshallUint64(buf[164:172]))
+
+	// Field (0) 'AttestedHeader'
+	{
+		buf = tail[o0:]
+		if l.AttestedHeader == nil {
+			l.AttestedHeader = new(LightClientHeaderDeneb)
+		}
+		if err = l.AttestedHeader.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the LightClientOptimisticUpdateDeneb object
+func (l *LightClientOptimisticUpdateDeneb) SizeSSZ() (size int) {
+	size = 172
+
+	// Field (0) 'AttestedHeader'
+	if l.AttestedHeader == nil {
+		l.AttestedHeader = new(LightClientHeaderDeneb)
+	}
+	size += l.AttestedHeader.SizeSSZ()
+
+	return
+}
+
+// HashTreeRoot ssz hashes the LightClientOptimisticUpdateDeneb object
+func (l *LightClientOptimisticUpdateDeneb) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(l)
+}
+
+// HashTreeRootWith ssz hashes the LightClientOptimisticUpdateDeneb object with a hasher
+func (l *LightClientOptimisticUpdateDeneb) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'AttestedHeader'
+	if err = l.AttestedHeader.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'SyncAggregate'
+	if err = l.SyncAggregate.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (2) 'SignatureSlot'
+	hh.PutUint64(uint64(l.SignatureSlot))
+
+	hh.Merkleize(indx)
+	return
+}

proto/prysm/v1alpha1/electra.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: 6d900c40d922575c27ef51a244f7bf935f56aa440017288a3405a3025d7750a6
+// Hash: 3a2dbf56ebf4e81fbf961840a4cd2addac9047b17c12bad04e60879df5b69277
 package eth
 
 import (
@@ -862,6 +862,215 @@ func (s *SignedBeaconBlockContentsElectra) HashTreeRootWith(hh *ssz.Hasher) (err
 	return
 }
 
+// MarshalSSZ ssz marshals the BeaconBlockContentsElectra object
+func (b *BeaconBlockContentsElectra) MarshalSSZ() ([]byte, error) {
+	return ssz.MarshalSSZ(b)
+}
+
+// MarshalSSZTo ssz marshals the BeaconBlockContentsElectra object to a target array
+func (b *BeaconBlockContentsElectra) MarshalSSZTo(buf []byte) (dst []byte, err error) {
+	dst = buf
+	offset := int(12)
+
+	// Offset (0) 'Block'
+	dst = ssz.WriteOffset(dst, offset)
+	if b.Block == nil {
+		b.Block = new(BeaconBlockElectra)
+	}
+	offset += b.Block.SizeSSZ()
+
+	// Offset (1) 'KzgProofs'
+	dst = ssz.WriteOffset(dst, offset)
+	offset += len(b.KzgProofs) * 48
+
+	// Offset (2) 'Blobs'
+	dst = ssz.WriteOffset(dst, offset)
+	offset += len(b.Blobs) * 131072
+
+	// Field (0) 'Block'
+	if dst, err = b.Block.MarshalSSZTo(dst); err != nil {
+		return
+	}
+
+	// Field (1) 'KzgProofs'
+	if size := len(b.KzgProofs); size > 4096 {
+		err = ssz.ErrListTooBigFn("--.KzgProofs", size, 4096)
+		return
+	}
+	for ii := 0; ii < len(b.KzgProofs); ii++ {
+		if size := len(b.KzgProofs[ii]); size != 48 {
+			err = ssz.ErrBytesLengthFn("--.KzgProofs[ii]", size, 48)
+			return
+		}
+		dst = append(dst, b.KzgProofs[ii]...)
+	}
+
+	// Field (2) 'Blobs'
+	if size := len(b.Blobs); size > 4096 {
+		err = ssz.ErrListTooBigFn("--.Blobs", size, 4096)
+		return
+	}
+	for ii := 0; ii < len(b.Blobs); ii++ {
+		if size := len(b.Blobs[ii]); size != 131072 {
+			err = ssz.ErrBytesLengthFn("--.Blobs[ii]", size, 131072)
+			return
+		}
+		dst = append(dst, b.Blobs[ii]...)
+	}
+
+	return
+}
+
+// UnmarshalSSZ ssz unmarshals the BeaconBlockContentsElectra object
+func (b *BeaconBlockContentsElectra) UnmarshalSSZ(buf []byte) error {
+	var err error
+	size := uint64(len(buf))
+	if size < 12 {
+		return ssz.ErrSize
+	}
+
+	tail := buf
+	var o0, o1, o2 uint64
+
+	// Offset (0) 'Block'
+	if o0 = ssz.ReadOffset(buf[0:4]); o0 > size {
+		return ssz.ErrOffset
+	}
+
+	if o0 != 12 {
+		return ssz.ErrInvalidVariableOffset
+	}
+
+	// Offset (1) 'KzgProofs'
+	if o1 = ssz.ReadOffset(buf[4:8]); o1 > size || o0 > o1 {
+		return ssz.ErrOffset
+	}
+
+	// Offset (2) 'Blobs'
+	if o2 = ssz.ReadOffset(buf[8:12]); o2 > size || o1 > o2 {
+		return ssz.ErrOffset
+	}
+
+	// Field (0) 'Block'
+	{
+		buf = tail[o0:o1]
+		if b.Block == nil {
+			b.Block = new(BeaconBlockElectra)
+		}
+		if err = b.Block.UnmarshalSSZ(buf); err != nil {
+			return err
+		}
+	}
+
+	// Field (1) 'KzgProofs'
+	{
+		buf = tail[o1:o2]
+		num, err := ssz.DivideInt2(len(buf), 48, 4096)
+		if err != nil {
+			return err
+		}
+		b.KzgProofs = make([][]byte, num)
+		for ii := 0; ii < num; ii++ {
+			if cap(b.KzgProofs[ii]) == 0 {
+				b.KzgProofs[ii] = make([]byte, 0, len(buf[ii*48:(ii+1)*48]))
+			}
+			b.KzgProofs[ii] = append(b.KzgProofs[ii], buf[ii*48:(ii+1)*48]...)
+		}
+	}
+
+	// Field (2) 'Blobs'
+	{
+		buf = tail[o2:]
+		num, err := ssz.DivideInt2(len(buf), 131072, 4096)
+		if err != nil {
+			return err
+		}
+		b.Blobs = make([][]byte, num)
+		for ii := 0; ii < num; ii++ {
+			if cap(b.Blobs[ii]) == 0 {
+				b.Blobs[ii] = make([]byte, 0, len(buf[ii*131072:(ii+1)*131072]))
+			}
+			b.Blobs[ii] = append(b.Blobs[ii], buf[ii*131072:(ii+1)*131072]...)
+		}
+	}
+	return err
+}
+
+// SizeSSZ returns the ssz encoded size in bytes for the BeaconBlockContentsElectra object
+func (b *BeaconBlockContentsElectra) SizeSSZ() (size int) {
+	size = 12
+
+	// Field (0) 'Block'
+	if b.Block == nil {
+		b.Block = new(BeaconBlockElectra)
+	}
+	size += b.Block.SizeSSZ()
+
+	// Field (1) 'KzgProofs'
+	size += len(b.KzgProofs) * 48
+
+	// Field (2) 'Blobs'
+	size += len(b.Blobs) * 131072
+
+	return
+}
+
+// HashTreeRoot ssz hashes the BeaconBlockContentsElectra object
+func (b *BeaconBlockContentsElectra) HashTreeRoot() ([32]byte, error) {
+	return ssz.HashWithDefaultHasher(b)
+}
+
+// HashTreeRootWith ssz hashes the BeaconBlockContentsElectra object with a hasher
+func (b *BeaconBlockContentsElectra) HashTreeRootWith(hh *ssz.Hasher) (err error) {
+	indx := hh.Index()
+
+	// Field (0) 'Block'
+	if err = b.Block.HashTreeRootWith(hh); err != nil {
+		return
+	}
+
+	// Field (1) 'KzgProofs'
+	{
+		if size := len(b.KzgProofs); size > 4096 {
+			err = ssz.ErrListTooBigFn("--.KzgProofs", size, 4096)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range b.KzgProofs {
+			if len(i) != 48 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.PutBytes(i)
+		}
+
+		numItems := uint64(len(b.KzgProofs))
+		hh.MerkleizeWithMixin(subIndx, numItems, 4096)
+	}
+
+	// Field (2) 'Blobs'
+	{
+		if size := len(b.Blobs); size > 4096 {
+			err = ssz.ErrListTooBigFn("--.Blobs", size, 4096)
+			return
+		}
+		subIndx := hh.Index()
+		for _, i := range b.Blobs {
+			if len(i) != 131072 {
+				err = ssz.ErrBytesLength
+				return
+			}
+			hh.PutBytes(i)
+		}
+
+		numItems := uint64(len(b.Blobs))
+		hh.MerkleizeWithMixin(subIndx, numItems, 4096)
+	}
+
+	hh.Merkleize(indx)
+	return
+}
+
 // MarshalSSZ ssz marshals the SignedBeaconBlockElectra object
 func (s *SignedBeaconBlockElectra) MarshalSSZ() ([]byte, error) {
 	return ssz.MarshalSSZ(s)

proto/prysm/v1alpha1/light_client.proto

@@ -0,0 +1,134 @@
+// Copyright 2024 Prysmatic Labs.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+syntax = "proto3";
+
+package ethereum.eth.v1alpha1;
+
+import "proto/eth/ext/options.proto";
+import "proto/prysm/v1alpha1/beacon_block.proto";
+import "proto/engine/v1/execution_engine.proto";
+import "proto/prysm/v1alpha1/beacon_state.proto";
+
+option csharp_namespace = "Ethereum.Eth.V1alpha1";
+option go_package = "github.com/prysmaticlabs/prysm/v5/proto/eth/v1alpha1;eth";
+option java_multiple_files = true;
+option java_outer_classname = "LightClientProto";
+option java_package = "org.ethereum.eth.v1alpha1";
+option php_namespace = "Ethereum\\Eth\\v1alpha1";
+
+message LightClientHeaderAltair {
+  BeaconBlockHeader beacon = 1;
+}
+
+message LightClientHeaderCapella {
+  BeaconBlockHeader beacon = 1;
+  ethereum.engine.v1.ExecutionPayloadHeaderCapella execution = 2;
+  repeated bytes execution_branch = 3 [(ethereum.eth.ext.ssz_size) = "4,32"];
+}
+
+message LightClientHeaderDeneb {
+  BeaconBlockHeader beacon = 1;
+  ethereum.engine.v1.ExecutionPayloadHeaderDeneb execution = 2;
+  repeated bytes execution_branch = 3 [(ethereum.eth.ext.ssz_size) = "4,32"];
+}
+
+message LightClientBootstrapAltair {
+  LightClientHeaderAltair header = 1;
+  SyncCommittee current_sync_committee = 2;
+  repeated bytes current_sync_committee_branch = 3 [(ethereum.eth.ext.ssz_size) = "5,32"];
+}
+
+message LightClientBootstrapCapella {
+  LightClientHeaderCapella header = 1;
+  SyncCommittee current_sync_committee = 2;
+  repeated bytes current_sync_committee_branch = 3 [(ethereum.eth.ext.ssz_size) = "5,32"];
+}
+
+message LightClientBootstrapDeneb {
+  LightClientHeaderDeneb header = 1;
+  SyncCommittee current_sync_committee = 2;
+  repeated bytes current_sync_committee_branch = 3 [(ethereum.eth.ext.ssz_size) = "5,32"];
+}
+
+message LightClientUpdateAltair {
+  LightClientHeaderAltair attested_header = 1;
+  SyncCommittee next_sync_committee = 2;
+  repeated bytes next_sync_committee_branch = 3 [(ethereum.eth.ext.ssz_size) = "5,32"];
+  LightClientHeaderAltair finalized_header = 4;
+  repeated bytes finality_branch = 5 [(ethereum.eth.ext.ssz_size) = "6,32"];
+  SyncAggregate sync_aggregate = 6;
+  uint64 signature_slot = 7 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientUpdateCapella {
+  LightClientHeaderCapella attested_header = 1;
+  SyncCommittee next_sync_committee = 2;
+  repeated bytes next_sync_committee_branch = 3 [(ethereum.eth.ext.ssz_size) = "5,32"];
+  LightClientHeaderCapella finalized_header = 4;
+  repeated bytes finality_branch = 5 [(ethereum.eth.ext.ssz_size) = "6,32"];
+  SyncAggregate sync_aggregate = 6;
+  uint64 signature_slot = 7 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientUpdateDeneb {
+  LightClientHeaderDeneb attested_header = 1;
+  SyncCommittee next_sync_committee = 2;
+  repeated bytes next_sync_committee_branch = 3 [(ethereum.eth.ext.ssz_size) = "5,32"];
+  LightClientHeaderDeneb finalized_header = 4;
+  repeated bytes finality_branch = 5 [(ethereum.eth.ext.ssz_size) = "6,32"];
+  SyncAggregate sync_aggregate = 6;
+  uint64 signature_slot = 7 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientFinalityUpdateAltair {
+  LightClientHeaderAltair attested_header = 1;
+  LightClientHeaderAltair finalized_header = 2;
+  repeated bytes finality_branch = 3 [(ethereum.eth.ext.ssz_size) = "6,32"];
+  SyncAggregate sync_aggregate = 4;
+  uint64 signature_slot = 5 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientFinalityUpdateCapella {
+  LightClientHeaderCapella attested_header = 1;
+  LightClientHeaderCapella finalized_header = 2;
+  repeated bytes finality_branch = 3 [(ethereum.eth.ext.ssz_size) = "6,32"];
+  SyncAggregate sync_aggregate = 4;
+  uint64 signature_slot = 5 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientFinalityUpdateDeneb {
+  LightClientHeaderDeneb attested_header = 1;
+  LightClientHeaderDeneb finalized_header = 2;
+  repeated bytes finality_branch = 3 [(ethereum.eth.ext.ssz_size) = "6,32"];
+  SyncAggregate sync_aggregate = 4;
+  uint64 signature_slot = 5 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientOptimisticUpdateAltair {
+  LightClientHeaderAltair attested_header = 1;
+  SyncAggregate sync_aggregate = 2;
+  uint64 signature_slot = 3 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientOptimisticUpdateCapella {
+  LightClientHeaderCapella attested_header = 1;
+  SyncAggregate sync_aggregate = 2;
+  uint64 signature_slot = 3 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}
+
+message LightClientOptimisticUpdateDeneb {
+  LightClientHeaderDeneb attested_header = 1;
+  SyncAggregate sync_aggregate = 2;
+  uint64 signature_slot = 3 [(ethereum.eth.ext.cast_type) = "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives.Slot"];
+}

proto/prysm/v1alpha1/non-core.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: 4cb7a5705004491db2ef29a5080a4cc56a1b618de948a86f9e5275858b48e6c4
+// Hash: bfd7d6b556134c3bd236b880245717aa01ae79573b33f2746a08c165ba5dcedb
 package eth
 
 import (

proto/prysm/v1alpha1/phase0.ssz.go

@@ -1,5 +1,5 @@
 // Code generated by fastssz. DO NOT EDIT.
-// Hash: 0afa289ce68dc2913d8000d495c6069832f35b66a6c0cf1bb0d1299fcad7047a
+// Hash: 5797213d138ec1a089f9dae2198cab6f4f829ac0cc1f0bda2633fff544db4e68
 package eth
 
 import (
@@ -3979,7 +3979,10 @@ func (v *Validator) UnmarshalSSZ(buf []byte) error {
 	v.EffectiveBalance = ssz.UnmarshallUint64(buf[80:88])
 
 	// Field (3) 'Slashed'
-	v.Slashed = ssz.UnmarshalBool(buf[88:89])
+	v.Slashed, err = ssz.DecodeBool(buf[88:89])
+	if err != nil {
+		return err
+	}
 
 	// Field (4) 'ActivationEligibilityEpoch'
 	v.ActivationEligibilityEpoch = github_com_prysmaticlabs_prysm_v5_consensus_types_primitives.Epoch(ssz.UnmarshallUint64(buf[89:97]))

runtime/interop/BUILD.bazel

@@ -49,6 +49,7 @@ go_test(
         "generate_genesis_state_bellatrix_test.go",
         "generate_genesis_state_test.go",
         "generate_keys_test.go",
+        "premine-state_test.go",
     ],
     data = [
         "keygen_test_vector.yaml",
@@ -61,9 +62,12 @@ go_test(
         "//container/trie:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
+        "//time:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
         "@com_github_go_yaml_yaml//:go_default_library",
         "@io_bazel_rules_go//go/tools/bazel:go_default_library",
     ],

runtime/interop/premine-state.go

@@ -155,6 +155,11 @@ func (s *PremineGenesisConfig) empty() (state.BeaconState, error) {
 		if err != nil {
 			return nil, err
 		}
+	case version.Electra:
+		e, err = state_native.InitializeFromProtoElectra(&ethpb.BeaconStateElectra{})
+		if err != nil {
+			return nil, err
+		}
 	default:
 		return nil, errUnsupportedVersion
 	}
@@ -336,6 +341,8 @@ func (s *PremineGenesisConfig) setFork(g state.BeaconState) error {
 		pv, cv = params.BeaconConfig().BellatrixForkVersion, params.BeaconConfig().CapellaForkVersion
 	case version.Deneb:
 		pv, cv = params.BeaconConfig().CapellaForkVersion, params.BeaconConfig().DenebForkVersion
+	case version.Electra:
+		pv, cv = params.BeaconConfig().ElectraForkVersion, params.BeaconConfig().ElectraForkVersion
 	default:
 		return errUnsupportedVersion
 	}
@@ -524,6 +531,39 @@ func (s *PremineGenesisConfig) setLatestBlockHeader(g state.BeaconState) error {
 			BlsToExecutionChanges: make([]*ethpb.SignedBLSToExecutionChange, 0),
 			BlobKzgCommitments:    make([][]byte, 0),
 		}
+	case version.Electra:
+		body = &ethpb.BeaconBlockBodyElectra{
+			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.ExecutionPayloadElectra{
+				ParentHash:    make([]byte, 32),
+				FeeRecipient:  make([]byte, 20),
+				StateRoot:     make([]byte, 32),
+				ReceiptsRoot:  make([]byte, 32),
+				LogsBloom:     make([]byte, 256),
+				PrevRandao:    make([]byte, 32),
+				ExtraData:     make([]byte, 0),
+				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),
+			ExecutionRequests: &enginev1.ExecutionRequests{
+				Deposits:       make([]*enginev1.DepositRequest, 0),
+				Withdrawals:    make([]*enginev1.WithdrawalRequest, 0),
+				Consolidations: make([]*enginev1.ConsolidationRequest, 0),
+			},
+		}
 	default:
 		return errUnsupportedVersion
 	}
@@ -640,6 +680,38 @@ func (s *PremineGenesisConfig) setExecutionPayload(g state.BeaconState) error {
 		if err != nil {
 			return err
 		}
+	case version.Electra:
+		payload := &enginev1.ExecutionPayloadElectra{
+			ParentHash:    gb.ParentHash().Bytes(),
+			FeeRecipient:  gb.Coinbase().Bytes(),
+			StateRoot:     gb.Root().Bytes(),
+			ReceiptsRoot:  gb.ReceiptHash().Bytes(),
+			LogsBloom:     gb.Bloom().Bytes(),
+			PrevRandao:    params.BeaconConfig().ZeroHash[:],
+			BlockNumber:   gb.NumberU64(),
+			GasLimit:      gb.GasLimit(),
+			GasUsed:       gb.GasUsed(),
+			Timestamp:     gb.Time(),
+			ExtraData:     gb.Extra()[:32],
+			BaseFeePerGas: bytesutil.PadTo(bytesutil.ReverseByteOrder(gb.BaseFee().Bytes()), fieldparams.RootLength),
+			BlockHash:     gb.Hash().Bytes(),
+			Transactions:  make([][]byte, 0),
+			Withdrawals:   make([]*enginev1.Withdrawal, 0),
+			ExcessBlobGas: *gb.ExcessBlobGas(),
+			BlobGasUsed:   *gb.BlobGasUsed(),
+		}
+		wep, err := blocks.WrappedExecutionPayloadElectra(payload)
+		if err != nil {
+			return err
+		}
+		eph, err := blocks.PayloadToHeaderElectra(wep)
+		if err != nil {
+			return err
+		}
+		ed, err = blocks.WrappedExecutionPayloadHeaderElectra(eph)
+		if err != nil {
+			return err
+		}
 	default:
 		return errUnsupportedVersion
 	}

runtime/interop/premine-state_test.go

@@ -0,0 +1,26 @@
+package interop
+
+import (
+	"context"
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/time"
+)
+
+func TestPremineGenesis_Electra(t *testing.T) {
+	one := uint64(1)
+
+	genesis := types.NewBlockWithHeader(&types.Header{
+		Time:          uint64(time.Now().Unix()),
+		Extra:         make([]byte, 32),
+		BaseFee:       big.NewInt(1),
+		ExcessBlobGas: &one,
+		BlobGasUsed:   &one,
+	})
+	_, err := NewPreminedGenesis(context.Background(), genesis.Time(), 10, 10, version.Electra, genesis)
+	require.NoError(t, err)
+}

testing/util/BUILD.bazel

@@ -43,6 +43,7 @@ go_library(
         "//beacon-chain/state/stateutil:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params: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",
@@ -51,6 +52,7 @@ go_library(
         "//crypto/hash:go_default_library",
         "//crypto/rand:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//encoding/ssz:go_default_library",
         "//network/forks:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",

testing/util/lightclient.go

@@ -4,14 +4,20 @@ import (
 	"context"
 	"testing"
 
+	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
+	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/encoding/ssz"
+	v11 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
 
@@ -21,7 +27,7 @@ type TestLightClient struct {
 	State          state.BeaconState
 	Block          interfaces.ReadOnlySignedBeaconBlock
 	AttestedState  state.BeaconState
-	AttestedHeader *ethpb.BeaconBlockHeader
+	AttestedBlock  interfaces.ReadOnlySignedBeaconBlock
 	FinalizedBlock interfaces.ReadOnlySignedBeaconBlock
 }
 
@@ -39,6 +45,19 @@ func (l *TestLightClient) SetupTestCapella(blinded bool) *TestLightClient {
 	err = attestedState.SetSlot(slot)
 	require.NoError(l.T, err)
 
+	finalizedBlock, err := blocks.NewSignedBeaconBlock(NewBeaconBlockCapella())
+	require.NoError(l.T, err)
+	finalizedBlock.SetSlot(1)
+	finalizedHeader, err := finalizedBlock.Header()
+	require.NoError(l.T, err)
+	finalizedRoot, err := finalizedHeader.Header.HashTreeRoot()
+	require.NoError(l.T, err)
+
+	require.NoError(l.T, attestedState.SetFinalizedCheckpoint(&ethpb.Checkpoint{
+		Epoch: params.BeaconConfig().CapellaForkEpoch - 10,
+		Root:  finalizedRoot[:],
+	}))
+
 	parent := NewBeaconBlockCapella()
 	parent.Block.Slot = slot
 
@@ -120,9 +139,122 @@ func (l *TestLightClient) SetupTestCapella(blinded bool) *TestLightClient {
 
 	l.State = state
 	l.AttestedState = attestedState
-	l.AttestedHeader = attestedHeader
+	l.AttestedBlock = signedParent
 	l.Block = signedBlock
 	l.Ctx = ctx
+	l.FinalizedBlock = finalizedBlock
+
+	return l
+}
+
+func (l *TestLightClient) SetupTestCapellaFinalizedBlockAltair(blinded bool) *TestLightClient {
+	ctx := context.Background()
+
+	slot := primitives.Slot(params.BeaconConfig().CapellaForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
+
+	attestedState, err := NewBeaconStateCapella()
+	require.NoError(l.T, err)
+	err = attestedState.SetSlot(slot)
+	require.NoError(l.T, err)
+
+	finalizedBlock, err := blocks.NewSignedBeaconBlock(NewBeaconBlockAltair())
+	require.NoError(l.T, err)
+	finalizedBlock.SetSlot(1)
+	finalizedHeader, err := finalizedBlock.Header()
+	require.NoError(l.T, err)
+	finalizedRoot, err := finalizedHeader.Header.HashTreeRoot()
+	require.NoError(l.T, err)
+
+	require.NoError(l.T, attestedState.SetFinalizedCheckpoint(&ethpb.Checkpoint{
+		Epoch: params.BeaconConfig().AltairForkEpoch - 10,
+		Root:  finalizedRoot[:],
+	}))
+
+	parent := NewBeaconBlockCapella()
+	parent.Block.Slot = slot
+
+	signedParent, err := blocks.NewSignedBeaconBlock(parent)
+	require.NoError(l.T, err)
+
+	parentHeader, err := signedParent.Header()
+	require.NoError(l.T, err)
+	attestedHeader := parentHeader.Header
+
+	err = attestedState.SetLatestBlockHeader(attestedHeader)
+	require.NoError(l.T, err)
+	attestedStateRoot, err := attestedState.HashTreeRoot(ctx)
+	require.NoError(l.T, err)
+
+	// get a new signed block so the root is updated with the new state root
+	parent.Block.StateRoot = attestedStateRoot[:]
+	signedParent, err = blocks.NewSignedBeaconBlock(parent)
+	require.NoError(l.T, err)
+
+	state, err := NewBeaconStateCapella()
+	require.NoError(l.T, err)
+	err = state.SetSlot(slot)
+	require.NoError(l.T, err)
+
+	parentRoot, err := signedParent.Block().HashTreeRoot()
+	require.NoError(l.T, err)
+
+	var signedBlock interfaces.SignedBeaconBlock
+	if blinded {
+		block := NewBlindedBeaconBlockCapella()
+		block.Block.Slot = slot
+		block.Block.ParentRoot = parentRoot[:]
+
+		for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
+			block.Block.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
+		}
+
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+
+		h, err := signedBlock.Header()
+		require.NoError(l.T, err)
+
+		err = state.SetLatestBlockHeader(h.Header)
+		require.NoError(l.T, err)
+		stateRoot, err := state.HashTreeRoot(ctx)
+		require.NoError(l.T, err)
+
+		// get a new signed block so the root is updated with the new state root
+		block.Block.StateRoot = stateRoot[:]
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+	} else {
+		block := NewBeaconBlockCapella()
+		block.Block.Slot = slot
+		block.Block.ParentRoot = parentRoot[:]
+
+		for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
+			block.Block.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
+		}
+
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+
+		h, err := signedBlock.Header()
+		require.NoError(l.T, err)
+
+		err = state.SetLatestBlockHeader(h.Header)
+		require.NoError(l.T, err)
+		stateRoot, err := state.HashTreeRoot(ctx)
+		require.NoError(l.T, err)
+
+		// get a new signed block so the root is updated with the new state root
+		block.Block.StateRoot = stateRoot[:]
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+	}
+
+	l.State = state
+	l.AttestedState = attestedState
+	l.AttestedBlock = signedParent
+	l.Block = signedBlock
+	l.Ctx = ctx
+	l.FinalizedBlock = finalizedBlock
 
 	return l
 }
@@ -137,6 +269,19 @@ func (l *TestLightClient) SetupTestAltair() *TestLightClient {
 	err = attestedState.SetSlot(slot)
 	require.NoError(l.T, err)
 
+	finalizedBlock, err := blocks.NewSignedBeaconBlock(NewBeaconBlockAltair())
+	require.NoError(l.T, err)
+	finalizedBlock.SetSlot(1)
+	finalizedHeader, err := finalizedBlock.Header()
+	require.NoError(l.T, err)
+	finalizedRoot, err := finalizedHeader.Header.HashTreeRoot()
+	require.NoError(l.T, err)
+
+	require.NoError(l.T, attestedState.SetFinalizedCheckpoint(&ethpb.Checkpoint{
+		Epoch: params.BeaconConfig().AltairForkEpoch - 10,
+		Root:  finalizedRoot[:],
+	}))
+
 	parent := NewBeaconBlockAltair()
 	parent.Block.Slot = slot
 
@@ -191,9 +336,10 @@ func (l *TestLightClient) SetupTestAltair() *TestLightClient {
 
 	l.State = state
 	l.AttestedState = attestedState
-	l.AttestedHeader = attestedHeader
 	l.Block = signedBlock
 	l.Ctx = ctx
+	l.FinalizedBlock = finalizedBlock
+	l.AttestedBlock = signedParent
 
 	return l
 }
@@ -208,6 +354,19 @@ func (l *TestLightClient) SetupTestDeneb(blinded bool) *TestLightClient {
 	err = attestedState.SetSlot(slot)
 	require.NoError(l.T, err)
 
+	finalizedBlock, err := blocks.NewSignedBeaconBlock(NewBeaconBlockDeneb())
+	require.NoError(l.T, err)
+	finalizedBlock.SetSlot(1)
+	finalizedHeader, err := finalizedBlock.Header()
+	require.NoError(l.T, err)
+	finalizedRoot, err := finalizedHeader.Header.HashTreeRoot()
+	require.NoError(l.T, err)
+
+	require.NoError(l.T, attestedState.SetFinalizedCheckpoint(&ethpb.Checkpoint{
+		Epoch: params.BeaconConfig().DenebForkEpoch - 10,
+		Root:  finalizedRoot[:],
+	}))
+
 	parent := NewBeaconBlockDeneb()
 	parent.Block.Slot = slot
 
@@ -289,9 +448,234 @@ func (l *TestLightClient) SetupTestDeneb(blinded bool) *TestLightClient {
 
 	l.State = state
 	l.AttestedState = attestedState
-	l.AttestedHeader = attestedHeader
+	l.AttestedBlock = signedParent
 	l.Block = signedBlock
 	l.Ctx = ctx
+	l.FinalizedBlock = finalizedBlock
+
+	return l
+}
+
+func (l *TestLightClient) SetupTestElectra(blinded bool) *TestLightClient {
+	ctx := context.Background()
+
+	slot := primitives.Slot(params.BeaconConfig().ElectraForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
+
+	attestedState, err := NewBeaconStateElectra()
+	require.NoError(l.T, err)
+	err = attestedState.SetSlot(slot)
+	require.NoError(l.T, err)
+
+	finalizedBlock, err := blocks.NewSignedBeaconBlock(NewBeaconBlockElectra())
+	require.NoError(l.T, err)
+	finalizedBlock.SetSlot(1)
+	finalizedHeader, err := finalizedBlock.Header()
+	require.NoError(l.T, err)
+	finalizedRoot, err := finalizedHeader.Header.HashTreeRoot()
+	require.NoError(l.T, err)
+
+	require.NoError(l.T, attestedState.SetFinalizedCheckpoint(&ethpb.Checkpoint{
+		Epoch: params.BeaconConfig().ElectraForkEpoch - 10,
+		Root:  finalizedRoot[:],
+	}))
+
+	parent := NewBeaconBlockElectra()
+	parent.Block.Slot = slot
+
+	signedParent, err := blocks.NewSignedBeaconBlock(parent)
+	require.NoError(l.T, err)
+
+	parentHeader, err := signedParent.Header()
+	require.NoError(l.T, err)
+	attestedHeader := parentHeader.Header
+
+	err = attestedState.SetLatestBlockHeader(attestedHeader)
+	require.NoError(l.T, err)
+	attestedStateRoot, err := attestedState.HashTreeRoot(ctx)
+	require.NoError(l.T, err)
+
+	// get a new signed block so the root is updated with the new state root
+	parent.Block.StateRoot = attestedStateRoot[:]
+	signedParent, err = blocks.NewSignedBeaconBlock(parent)
+	require.NoError(l.T, err)
+
+	state, err := NewBeaconStateElectra()
+	require.NoError(l.T, err)
+	err = state.SetSlot(slot)
+	require.NoError(l.T, err)
+
+	parentRoot, err := signedParent.Block().HashTreeRoot()
+	require.NoError(l.T, err)
+
+	var signedBlock interfaces.SignedBeaconBlock
+	if blinded {
+		block := NewBlindedBeaconBlockElectra()
+		block.Message.Slot = slot
+		block.Message.ParentRoot = parentRoot[:]
+
+		for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
+			block.Message.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
+		}
+
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+
+		h, err := signedBlock.Header()
+		require.NoError(l.T, err)
+
+		err = state.SetLatestBlockHeader(h.Header)
+		require.NoError(l.T, err)
+		stateRoot, err := state.HashTreeRoot(ctx)
+		require.NoError(l.T, err)
+
+		// get a new signed block so the root is updated with the new state root
+		block.Message.StateRoot = stateRoot[:]
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+	} else {
+		block := NewBeaconBlockElectra()
+		block.Block.Slot = slot
+		block.Block.ParentRoot = parentRoot[:]
+
+		for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
+			block.Block.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
+		}
+
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+
+		h, err := signedBlock.Header()
+		require.NoError(l.T, err)
+
+		err = state.SetLatestBlockHeader(h.Header)
+		require.NoError(l.T, err)
+		stateRoot, err := state.HashTreeRoot(ctx)
+		require.NoError(l.T, err)
+
+		// get a new signed block so the root is updated with the new state root
+		block.Block.StateRoot = stateRoot[:]
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+	}
+
+	l.State = state
+	l.AttestedState = attestedState
+	l.AttestedBlock = signedParent
+	l.Block = signedBlock
+	l.Ctx = ctx
+	l.FinalizedBlock = finalizedBlock
+
+	return l
+}
+
+func (l *TestLightClient) SetupTestDenebFinalizedBlockCapella(blinded bool) *TestLightClient {
+	ctx := context.Background()
+
+	slot := primitives.Slot(params.BeaconConfig().DenebForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
+
+	attestedState, err := NewBeaconStateDeneb()
+	require.NoError(l.T, err)
+	err = attestedState.SetSlot(slot)
+	require.NoError(l.T, err)
+
+	finalizedBlock, err := blocks.NewSignedBeaconBlock(NewBeaconBlockCapella())
+	require.NoError(l.T, err)
+	finalizedBlock.SetSlot(1)
+	finalizedHeader, err := finalizedBlock.Header()
+	require.NoError(l.T, err)
+	finalizedRoot, err := finalizedHeader.Header.HashTreeRoot()
+	require.NoError(l.T, err)
+
+	require.NoError(l.T, attestedState.SetFinalizedCheckpoint(&ethpb.Checkpoint{
+		Epoch: params.BeaconConfig().CapellaForkEpoch - 10,
+		Root:  finalizedRoot[:],
+	}))
+
+	parent := NewBeaconBlockDeneb()
+	parent.Block.Slot = slot
+
+	signedParent, err := blocks.NewSignedBeaconBlock(parent)
+	require.NoError(l.T, err)
+
+	parentHeader, err := signedParent.Header()
+	require.NoError(l.T, err)
+	attestedHeader := parentHeader.Header
+
+	err = attestedState.SetLatestBlockHeader(attestedHeader)
+	require.NoError(l.T, err)
+	attestedStateRoot, err := attestedState.HashTreeRoot(ctx)
+	require.NoError(l.T, err)
+
+	// get a new signed block so the root is updated with the new state root
+	parent.Block.StateRoot = attestedStateRoot[:]
+	signedParent, err = blocks.NewSignedBeaconBlock(parent)
+	require.NoError(l.T, err)
+
+	state, err := NewBeaconStateDeneb()
+	require.NoError(l.T, err)
+	err = state.SetSlot(slot)
+	require.NoError(l.T, err)
+
+	parentRoot, err := signedParent.Block().HashTreeRoot()
+	require.NoError(l.T, err)
+
+	var signedBlock interfaces.SignedBeaconBlock
+	if blinded {
+		block := NewBlindedBeaconBlockDeneb()
+		block.Message.Slot = slot
+		block.Message.ParentRoot = parentRoot[:]
+
+		for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
+			block.Message.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
+		}
+
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+
+		h, err := signedBlock.Header()
+		require.NoError(l.T, err)
+
+		err = state.SetLatestBlockHeader(h.Header)
+		require.NoError(l.T, err)
+		stateRoot, err := state.HashTreeRoot(ctx)
+		require.NoError(l.T, err)
+
+		// get a new signed block so the root is updated with the new state root
+		block.Message.StateRoot = stateRoot[:]
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+	} else {
+		block := NewBeaconBlockDeneb()
+		block.Block.Slot = slot
+		block.Block.ParentRoot = parentRoot[:]
+
+		for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
+			block.Block.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
+		}
+
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+
+		h, err := signedBlock.Header()
+		require.NoError(l.T, err)
+
+		err = state.SetLatestBlockHeader(h.Header)
+		require.NoError(l.T, err)
+		stateRoot, err := state.HashTreeRoot(ctx)
+		require.NoError(l.T, err)
+
+		// get a new signed block so the root is updated with the new state root
+		block.Block.StateRoot = stateRoot[:]
+		signedBlock, err = blocks.NewSignedBeaconBlock(block)
+		require.NoError(l.T, err)
+	}
+
+	l.State = state
+	l.AttestedState = attestedState
+	l.AttestedBlock = signedParent
+	l.Block = signedBlock
+	l.Ctx = ctx
+	l.FinalizedBlock = finalizedBlock
 
 	return l
 }
@@ -299,14 +683,124 @@ func (l *TestLightClient) SetupTestDeneb(blinded bool) *TestLightClient {
 func (l *TestLightClient) CheckAttestedHeader(container *ethpbv2.LightClientHeaderContainer) {
 	updateAttestedHeaderBeacon, err := container.GetBeacon()
 	require.NoError(l.T, err)
-	require.Equal(l.T, l.AttestedHeader.Slot, updateAttestedHeaderBeacon.Slot, "Attested header slot is not equal")
-	require.Equal(l.T, l.AttestedHeader.ProposerIndex, updateAttestedHeaderBeacon.ProposerIndex, "Attested header proposer index is not equal")
-	require.DeepSSZEqual(l.T, l.AttestedHeader.ParentRoot, updateAttestedHeaderBeacon.ParentRoot, "Attested header parent root is not equal")
-	require.DeepSSZEqual(l.T, l.AttestedHeader.BodyRoot, updateAttestedHeaderBeacon.BodyRoot, "Attested header body root is not equal")
+	testAttestedHeader, err := l.AttestedBlock.Header()
+	require.NoError(l.T, err)
+	require.Equal(l.T, l.AttestedBlock.Block().Slot(), updateAttestedHeaderBeacon.Slot, "Attested block slot is not equal")
+	require.Equal(l.T, testAttestedHeader.Header.ProposerIndex, updateAttestedHeaderBeacon.ProposerIndex, "Attested block proposer index is not equal")
+	require.DeepSSZEqual(l.T, testAttestedHeader.Header.ParentRoot, updateAttestedHeaderBeacon.ParentRoot, "Attested block parent root is not equal")
+	require.DeepSSZEqual(l.T, testAttestedHeader.Header.BodyRoot, updateAttestedHeaderBeacon.BodyRoot, "Attested block body root is not equal")
 
 	attestedStateRoot, err := l.AttestedState.HashTreeRoot(l.Ctx)
 	require.NoError(l.T, err)
-	require.DeepSSZEqual(l.T, attestedStateRoot[:], updateAttestedHeaderBeacon.StateRoot, "Attested header state root is not equal")
+	require.DeepSSZEqual(l.T, attestedStateRoot[:], updateAttestedHeaderBeacon.StateRoot, "Attested block state root is not equal")
+
+	if l.AttestedBlock.Version() == version.Capella {
+		payloadInterface, err := l.AttestedBlock.Block().Body().Execution()
+		require.NoError(l.T, err)
+		transactionsRoot, err := payloadInterface.TransactionsRoot()
+		if errors.Is(err, consensus_types.ErrUnsupportedField) {
+			transactions, err := payloadInterface.Transactions()
+			require.NoError(l.T, err)
+			transactionsRootArray, err := ssz.TransactionsRoot(transactions)
+			require.NoError(l.T, err)
+			transactionsRoot = transactionsRootArray[:]
+		} else {
+			require.NoError(l.T, err)
+		}
+		withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
+		if errors.Is(err, consensus_types.ErrUnsupportedField) {
+			withdrawals, err := payloadInterface.Withdrawals()
+			require.NoError(l.T, err)
+			withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+			require.NoError(l.T, err)
+			withdrawalsRoot = withdrawalsRootArray[:]
+		} else {
+			require.NoError(l.T, err)
+		}
+		execution := &v11.ExecutionPayloadHeaderCapella{
+			ParentHash:       payloadInterface.ParentHash(),
+			FeeRecipient:     payloadInterface.FeeRecipient(),
+			StateRoot:        payloadInterface.StateRoot(),
+			ReceiptsRoot:     payloadInterface.ReceiptsRoot(),
+			LogsBloom:        payloadInterface.LogsBloom(),
+			PrevRandao:       payloadInterface.PrevRandao(),
+			BlockNumber:      payloadInterface.BlockNumber(),
+			GasLimit:         payloadInterface.GasLimit(),
+			GasUsed:          payloadInterface.GasUsed(),
+			Timestamp:        payloadInterface.Timestamp(),
+			ExtraData:        payloadInterface.ExtraData(),
+			BaseFeePerGas:    payloadInterface.BaseFeePerGas(),
+			BlockHash:        payloadInterface.BlockHash(),
+			TransactionsRoot: transactionsRoot,
+			WithdrawalsRoot:  withdrawalsRoot,
+		}
+
+		updateAttestedHeaderExecution, err := container.GetExecutionHeaderCapella()
+		require.NoError(l.T, err)
+		require.DeepSSZEqual(l.T, execution, updateAttestedHeaderExecution, "Attested Block Execution is not equal")
+
+		executionPayloadProof, err := blocks.PayloadProof(l.Ctx, l.AttestedBlock.Block())
+		require.NoError(l.T, err)
+		updateAttestedHeaderExecutionBranch, err := container.GetExecutionBranch()
+		require.NoError(l.T, err)
+		for i, leaf := range updateAttestedHeaderExecutionBranch {
+			require.DeepSSZEqual(l.T, executionPayloadProof[i], leaf, "Leaf is not equal")
+		}
+	}
+
+	if l.AttestedBlock.Version() == version.Deneb {
+		payloadInterface, err := l.AttestedBlock.Block().Body().Execution()
+		require.NoError(l.T, err)
+		transactionsRoot, err := payloadInterface.TransactionsRoot()
+		if errors.Is(err, consensus_types.ErrUnsupportedField) {
+			transactions, err := payloadInterface.Transactions()
+			require.NoError(l.T, err)
+			transactionsRootArray, err := ssz.TransactionsRoot(transactions)
+			require.NoError(l.T, err)
+			transactionsRoot = transactionsRootArray[:]
+		} else {
+			require.NoError(l.T, err)
+		}
+		withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
+		if errors.Is(err, consensus_types.ErrUnsupportedField) {
+			withdrawals, err := payloadInterface.Withdrawals()
+			require.NoError(l.T, err)
+			withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+			require.NoError(l.T, err)
+			withdrawalsRoot = withdrawalsRootArray[:]
+		} else {
+			require.NoError(l.T, err)
+		}
+		execution := &v11.ExecutionPayloadHeaderDeneb{
+			ParentHash:       payloadInterface.ParentHash(),
+			FeeRecipient:     payloadInterface.FeeRecipient(),
+			StateRoot:        payloadInterface.StateRoot(),
+			ReceiptsRoot:     payloadInterface.ReceiptsRoot(),
+			LogsBloom:        payloadInterface.LogsBloom(),
+			PrevRandao:       payloadInterface.PrevRandao(),
+			BlockNumber:      payloadInterface.BlockNumber(),
+			GasLimit:         payloadInterface.GasLimit(),
+			GasUsed:          payloadInterface.GasUsed(),
+			Timestamp:        payloadInterface.Timestamp(),
+			ExtraData:        payloadInterface.ExtraData(),
+			BaseFeePerGas:    payloadInterface.BaseFeePerGas(),
+			BlockHash:        payloadInterface.BlockHash(),
+			TransactionsRoot: transactionsRoot,
+			WithdrawalsRoot:  withdrawalsRoot,
+		}
+
+		updateAttestedHeaderExecution, err := container.GetExecutionHeaderDeneb()
+		require.NoError(l.T, err)
+		require.DeepSSZEqual(l.T, execution, updateAttestedHeaderExecution, "Attested Block Execution is not equal")
+
+		executionPayloadProof, err := blocks.PayloadProof(l.Ctx, l.AttestedBlock.Block())
+		require.NoError(l.T, err)
+		updateAttestedHeaderExecutionBranch, err := container.GetExecutionBranch()
+		require.NoError(l.T, err)
+		for i, leaf := range updateAttestedHeaderExecutionBranch {
+			require.DeepSSZEqual(l.T, executionPayloadProof[i], leaf, "Leaf is not equal")
+		}
+	}
 }
 
 func (l *TestLightClient) CheckSyncAggregate(sa *ethpbv1.SyncAggregate) {

validator/client/validator.go

@@ -1262,13 +1262,16 @@ func (v *validator) updateValidatorStatusCache(ctx context.Context, pubkeys [][f
 	if len(resp.Statuses) != len(resp.Indices) {
 		return fmt.Errorf("expected %d indices in status, received %d", len(resp.Statuses), len(resp.Indices))
 	}
+	pubkeyToStatus := make(map[[fieldparams.BLSPubkeyLength]byte]*validatorStatus, len(resp.Statuses))
 	for i, s := range resp.Statuses {
-		v.pubkeyToStatus[bytesutil.ToBytes48(resp.PublicKeys[i])] = &validatorStatus{
+		pubkeyToStatus[bytesutil.ToBytes48(resp.PublicKeys[i])] = &validatorStatus{
 			publicKey: resp.PublicKeys[i],
 			status:    s,
 			index:     resp.Indices[i],
 		}
 	}
+	v.pubkeyToStatus = pubkeyToStatus
+
 	return nil
 }
 

validator/client/validator_test.go

@@ -2908,3 +2908,63 @@ func TestValidator_ChangeHost(t *testing.T) {
 	v.ChangeHost()
 	assert.Equal(t, uint64(0), v.currentHostIndex)
 }
+
+func TestUpdateValidatorStatusCache(t *testing.T) {
+	ctx := context.Background()
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	pubkeys := [][fieldparams.BLSPubkeyLength]byte{
+		{0x01},
+		{0x02},
+	}
+	statusRequestKeys := [][]byte{
+		pubkeys[0][:],
+		pubkeys[1][:],
+	}
+
+	client := validatormock.NewMockValidatorClient(ctrl)
+	mockResponse := &ethpb.MultipleValidatorStatusResponse{
+		PublicKeys: statusRequestKeys,
+		Statuses: []*ethpb.ValidatorStatusResponse{
+			{
+				Status: ethpb.ValidatorStatus_ACTIVE,
+			}, {
+				Status: ethpb.ValidatorStatus_EXITING,
+			}},
+		Indices: []primitives.ValidatorIndex{1, 2},
+	}
+	client.EXPECT().MultipleValidatorStatus(
+		gomock.Any(),
+		gomock.Any()).Return(mockResponse, nil)
+
+	v := &validator{
+		validatorClient:  client,
+		beaconNodeHosts:  []string{"http://localhost:8080", "http://localhost:8081"},
+		currentHostIndex: 0,
+		pubkeyToStatus: map[[fieldparams.BLSPubkeyLength]byte]*validatorStatus{
+			[fieldparams.BLSPubkeyLength]byte{0x03}: &validatorStatus{ // add non existant key and status to cache, should be fully removed on update
+				publicKey: []byte{0x03},
+				status: &ethpb.ValidatorStatusResponse{
+					Status: ethpb.ValidatorStatus_ACTIVE,
+				},
+				index: 3,
+			},
+		},
+	}
+
+	err := v.updateValidatorStatusCache(ctx, pubkeys)
+	assert.NoError(t, err)
+
+	// make sure the nonexistant key is fully removed
+	_, ok := v.pubkeyToStatus[[fieldparams.BLSPubkeyLength]byte{0x03}]
+	require.Equal(t, false, ok)
+	// make sure we only have the added values
+	assert.Equal(t, 2, len(v.pubkeyToStatus))
+	for i, pk := range pubkeys {
+		status, exists := v.pubkeyToStatus[pk]
+		require.Equal(t, true, exists)
+		require.DeepEqual(t, pk[:], status.publicKey)
+		require.Equal(t, mockResponse.Statuses[i], status.status)
+		require.Equal(t, mockResponse.Indices[i], status.index)
+	}
+}