Fix LC versioning bug (#15400)

* fix versioning

* changelog

* fix blockchain tests

* fix linter issue

* fix spec tests

* fix default lc update version

* fix lc header version

* gzl

* clean up the code

* Update testing/spectest/shared/common/light_client/update_ranking.go

Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>

* add fulu set up in update ranking

* pass att block to createDefaultLCUpdate

* address comments

* linter

* Update lightclient.go

* sort imports

---------

Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>

beacon-chain/blockchain/process_block_test.go

@@ -2796,7 +2796,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
 
 			// create and save old update
-			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(l.AttestedBlock)
 			require.NoError(t, err)
 
 			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
@@ -2848,7 +2848,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
 
 			// create and save old update
-			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(l.AttestedBlock)
 			require.NoError(t, err)
 
 			scb := make([]byte, 64)
@@ -2954,7 +2954,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
 
 			// create and save old update
-			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(l.AttestedBlock)
 			require.NoError(t, err)
 
 			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
@@ -3006,7 +3006,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
 
 			// create and save old update
-			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(l.AttestedBlock)
 			require.NoError(t, err)
 
 			scb := make([]byte, 64)
@@ -3112,7 +3112,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
 
 			// create and save old update
-			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(l.AttestedBlock)
 			require.NoError(t, err)
 
 			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
@@ -3164,7 +3164,7 @@ func TestProcessLightClientUpdate(t *testing.T) {
 			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
 
 			// create and save old update
-			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(l.AttestedBlock)
 			require.NoError(t, err)
 
 			scb := make([]byte, 64)
@@ -3647,7 +3647,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 				expectedVersion = version.Altair
 			case 2:
 				forkEpoch = uint64(params.BeaconConfig().BellatrixForkEpoch)
-				expectedVersion = version.Altair
+				expectedVersion = version.Bellatrix
 			case 3:
 				forkEpoch = uint64(params.BeaconConfig().CapellaForkEpoch)
 				expectedVersion = version.Capella
@@ -3656,7 +3656,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 				expectedVersion = version.Deneb
 			case 5:
 				forkEpoch = uint64(params.BeaconConfig().ElectraForkEpoch)
-				expectedVersion = version.Deneb
+				expectedVersion = version.Electra
 			default:
 				t.Errorf("Unsupported fork version %s", version.String(testVersion))
 			}
@@ -3801,7 +3801,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 				expectedVersion = version.Altair
 			case 2:
 				forkEpoch = uint64(params.BeaconConfig().BellatrixForkEpoch)
-				expectedVersion = version.Altair
+				expectedVersion = version.Bellatrix
 			case 3:
 				forkEpoch = uint64(params.BeaconConfig().CapellaForkEpoch)
 				expectedVersion = version.Capella

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

@@ -3,6 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "helpers.go",
         "lightclient.go",
         "store.go",
     ],
@@ -41,7 +42,6 @@ go_test(
         "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/light-client:go_default_library",
-        "//consensus-types/primitives:go_default_library",
         "//encoding/ssz:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",

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

@@ -0,0 +1,243 @@
+package light_client
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	light_client "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
+	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/pkg/errors"
+	"google.golang.org/protobuf/proto"
+)
+
+func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.LightClientBootstrap, error) {
+	currentEpoch := slots.ToEpoch(currentSlot)
+	syncCommitteeSize := params.BeaconConfig().SyncCommitteeSize
+	pubKeys := make([][]byte, syncCommitteeSize)
+	for i := uint64(0); i < syncCommitteeSize; i++ {
+		pubKeys[i] = make([]byte, fieldparams.BLSPubkeyLength)
+	}
+	currentSyncCommittee := &pb.SyncCommittee{
+		Pubkeys:         pubKeys,
+		AggregatePubkey: make([]byte, fieldparams.BLSPubkeyLength),
+	}
+
+	var currentSyncCommitteeBranch [][]byte
+	if currentEpoch >= params.BeaconConfig().ElectraForkEpoch {
+		currentSyncCommitteeBranch = make([][]byte, fieldparams.SyncCommitteeBranchDepthElectra)
+	} else {
+		currentSyncCommitteeBranch = make([][]byte, fieldparams.SyncCommitteeBranchDepth)
+	}
+	for i := 0; i < len(currentSyncCommitteeBranch); i++ {
+		currentSyncCommitteeBranch[i] = make([]byte, fieldparams.RootLength)
+	}
+
+	executionBranch := make([][]byte, fieldparams.ExecutionBranchDepth)
+	for i := 0; i < fieldparams.ExecutionBranchDepth; i++ {
+		executionBranch[i] = make([]byte, 32)
+	}
+
+	var m proto.Message
+	if currentEpoch < params.BeaconConfig().CapellaForkEpoch {
+		m = &pb.LightClientBootstrapAltair{
+			Header: &pb.LightClientHeaderAltair{
+				Beacon: &pb.BeaconBlockHeader{},
+			},
+			CurrentSyncCommittee:       currentSyncCommittee,
+			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
+		}
+	} else if currentEpoch < params.BeaconConfig().DenebForkEpoch {
+		m = &pb.LightClientBootstrapCapella{
+			Header: &pb.LightClientHeaderCapella{
+				Beacon:          &pb.BeaconBlockHeader{},
+				Execution:       &enginev1.ExecutionPayloadHeaderCapella{},
+				ExecutionBranch: executionBranch,
+			},
+			CurrentSyncCommittee:       currentSyncCommittee,
+			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
+		}
+	} else if currentEpoch < params.BeaconConfig().ElectraForkEpoch {
+		m = &pb.LightClientBootstrapDeneb{
+			Header: &pb.LightClientHeaderDeneb{
+				Beacon:          &pb.BeaconBlockHeader{},
+				Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
+				ExecutionBranch: executionBranch,
+			},
+			CurrentSyncCommittee:       currentSyncCommittee,
+			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
+		}
+	} else {
+		m = &pb.LightClientBootstrapElectra{
+			Header: &pb.LightClientHeaderDeneb{
+				Beacon:          &pb.BeaconBlockHeader{},
+				Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
+				ExecutionBranch: executionBranch,
+			},
+			CurrentSyncCommittee:       currentSyncCommittee,
+			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
+		}
+	}
+
+	return light_client.NewWrappedBootstrap(m)
+}
+
+func makeExecutionAndProofDeneb(ctx context.Context, blk interfaces.ReadOnlySignedBeaconBlock) (*enginev1.ExecutionPayloadHeaderDeneb, [][]byte, error) {
+	if blk.Version() < version.Capella {
+		p, err := execution.EmptyExecutionPayloadHeader(version.Deneb)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not get payload header")
+		}
+		payloadHeader, ok := p.(*enginev1.ExecutionPayloadHeaderDeneb)
+		if !ok {
+			return nil, nil, fmt.Errorf("payload header type %T is not %T", p, &enginev1.ExecutionPayloadHeaderDeneb{})
+		}
+		payloadProof := emptyPayloadProof()
+
+		return payloadHeader, payloadProof, nil
+	}
+
+	payload, err := blk.Block().Body().Execution()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get execution payload")
+	}
+	transactionsRoot, err := ComputeTransactionsRoot(payload)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get transactions root")
+	}
+	withdrawalsRoot, err := ComputeWithdrawalsRoot(payload)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get withdrawals root")
+	}
+
+	payloadHeader := &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       payload.ParentHash(),
+		FeeRecipient:     payload.FeeRecipient(),
+		StateRoot:        payload.StateRoot(),
+		ReceiptsRoot:     payload.ReceiptsRoot(),
+		LogsBloom:        payload.LogsBloom(),
+		PrevRandao:       payload.PrevRandao(),
+		BlockNumber:      payload.BlockNumber(),
+		GasLimit:         payload.GasLimit(),
+		GasUsed:          payload.GasUsed(),
+		Timestamp:        payload.Timestamp(),
+		ExtraData:        payload.ExtraData(),
+		BaseFeePerGas:    payload.BaseFeePerGas(),
+		BlockHash:        payload.BlockHash(),
+		TransactionsRoot: transactionsRoot,
+		WithdrawalsRoot:  withdrawalsRoot,
+		BlobGasUsed:      0,
+		ExcessBlobGas:    0,
+	}
+
+	if blk.Version() >= version.Deneb {
+		blobGasUsed, err := payload.BlobGasUsed()
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not get blob gas used")
+		}
+		excessBlobGas, err := payload.ExcessBlobGas()
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not get excess blob gas")
+		}
+
+		payloadHeader.BlobGasUsed = blobGasUsed
+		payloadHeader.ExcessBlobGas = excessBlobGas
+	}
+
+	payloadProof, err := blocks.PayloadProof(ctx, blk.Block())
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get execution payload proof")
+	}
+
+	return payloadHeader, payloadProof, nil
+}
+
+func makeExecutionAndProofCapella(ctx context.Context, blk interfaces.ReadOnlySignedBeaconBlock) (*enginev1.ExecutionPayloadHeaderCapella, [][]byte, error) {
+	if blk.Version() > version.Capella {
+		return nil, nil, fmt.Errorf("unsupported block version %s for capella execution payload", version.String(blk.Version()))
+	}
+	if blk.Version() < version.Capella {
+		p, err := execution.EmptyExecutionPayloadHeader(version.Capella)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not get payload header")
+		}
+		payloadHeader, ok := p.(*enginev1.ExecutionPayloadHeaderCapella)
+		if !ok {
+			return nil, nil, fmt.Errorf("payload header type %T is not %T", p, &enginev1.ExecutionPayloadHeaderCapella{})
+		}
+		payloadProof := emptyPayloadProof()
+
+		return payloadHeader, payloadProof, nil
+	}
+
+	payload, err := blk.Block().Body().Execution()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get execution payload")
+	}
+	transactionsRoot, err := ComputeTransactionsRoot(payload)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get transactions root")
+	}
+	withdrawalsRoot, err := ComputeWithdrawalsRoot(payload)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get withdrawals root")
+	}
+
+	payloadHeader := &enginev1.ExecutionPayloadHeaderCapella{
+		ParentHash:       payload.ParentHash(),
+		FeeRecipient:     payload.FeeRecipient(),
+		StateRoot:        payload.StateRoot(),
+		ReceiptsRoot:     payload.ReceiptsRoot(),
+		LogsBloom:        payload.LogsBloom(),
+		PrevRandao:       payload.PrevRandao(),
+		BlockNumber:      payload.BlockNumber(),
+		GasLimit:         payload.GasLimit(),
+		GasUsed:          payload.GasUsed(),
+		Timestamp:        payload.Timestamp(),
+		ExtraData:        payload.ExtraData(),
+		BaseFeePerGas:    payload.BaseFeePerGas(),
+		BlockHash:        payload.BlockHash(),
+		TransactionsRoot: transactionsRoot,
+		WithdrawalsRoot:  withdrawalsRoot,
+	}
+
+	payloadProof, err := blocks.PayloadProof(ctx, blk.Block())
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "could not get execution payload proof")
+	}
+
+	return payloadHeader, payloadProof, nil
+}
+
+func makeBeaconBlockHeader(blk interfaces.ReadOnlySignedBeaconBlock) (*pb.BeaconBlockHeader, error) {
+	parentRoot := blk.Block().ParentRoot()
+	stateRoot := blk.Block().StateRoot()
+	bodyRoot, err := blk.Block().Body().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get body root")
+	}
+	return &pb.BeaconBlockHeader{
+		Slot:          blk.Block().Slot(),
+		ProposerIndex: blk.Block().ProposerIndex(),
+		ParentRoot:    parentRoot[:],
+		StateRoot:     stateRoot[:],
+		BodyRoot:      bodyRoot[:],
+	}, nil
+}
+
+func emptyPayloadProof() [][]byte {
+	branch := interfaces.LightClientExecutionBranch{}
+	proof := make([][]byte, len(branch))
+	for i, b := range branch {
+		proof[i] = b[:]
+	}
+	return proof
+}

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

@@ -6,12 +6,10 @@ import (
 	"fmt"
 	"reflect"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	consensus_types "github.com/OffchainLabs/prysm/v6/consensus-types"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	light_client "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -163,13 +161,13 @@ func NewLightClientUpdateFromBeaconState(
 	updateAttestedPeriod := slots.SyncCommitteePeriod(slots.ToEpoch(attestedBlock.Block().Slot()))
 
 	// update = LightClientUpdate()
-	result, err := CreateDefaultLightClientUpdate(currentSlot, attestedState)
+	result, err := CreateDefaultLightClientUpdate(attestedBlock)
 	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)
-	attestedLightClientHeader, err := BlockToLightClientHeader(ctx, currentSlot, attestedBlock)
+	attestedLightClientHeader, err := BlockToLightClientHeader(ctx, attestedBlock.Version(), attestedBlock)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get attested light client header")
 	}
@@ -210,7 +208,7 @@ func NewLightClientUpdateFromBeaconState(
 		// if finalized_block.message.slot != GENESIS_SLOT
 		if finalizedBlock.Block().Slot() != 0 {
 			// update.finalized_header = block_to_light_client_header(finalized_block)
-			finalizedLightClientHeader, err := BlockToLightClientHeader(ctx, currentSlot, finalizedBlock)
+			finalizedLightClientHeader, err := BlockToLightClientHeader(ctx, attestedBlock.Version(), finalizedBlock)
 			if err != nil {
 				return nil, errors.Wrap(err, "could not get finalized light client header")
 			}
@@ -247,9 +245,7 @@ func NewLightClientUpdateFromBeaconState(
 	return result, nil
 }
 
-func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState state.BeaconState) (interfaces.LightClientUpdate, error) {
-	currentEpoch := slots.ToEpoch(currentSlot)
-
+func CreateDefaultLightClientUpdate(attestedBlock interfaces.ReadOnlySignedBeaconBlock) (interfaces.LightClientUpdate, error) {
 	syncCommitteeSize := params.BeaconConfig().SyncCommitteeSize
 	pubKeys := make([][]byte, syncCommitteeSize)
 	for i := uint64(0); i < syncCommitteeSize; i++ {
@@ -261,7 +257,7 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 	}
 
 	var nextSyncCommitteeBranch [][]byte
-	if attestedState.Version() >= version.Electra {
+	if attestedBlock.Version() >= version.Electra {
 		nextSyncCommitteeBranch = make([][]byte, fieldparams.SyncCommitteeBranchDepthElectra)
 	} else {
 		nextSyncCommitteeBranch = make([][]byte, fieldparams.SyncCommitteeBranchDepth)
@@ -276,7 +272,7 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 	}
 
 	var finalityBranch [][]byte
-	if attestedState.Version() >= version.Electra {
+	if attestedBlock.Version() >= version.Electra {
 		finalityBranch = make([][]byte, fieldparams.FinalityBranchDepthElectra)
 	} else {
 		finalityBranch = make([][]byte, fieldparams.FinalityBranchDepth)
@@ -286,10 +282,12 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 	}
 
 	var m proto.Message
-	if currentEpoch < params.BeaconConfig().CapellaForkEpoch {
+	switch attestedBlock.Version() {
+	case version.Altair, version.Bellatrix:
 		m = &pb.LightClientUpdateAltair{
 			AttestedHeader: &pb.LightClientHeaderAltair{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       attestedBlock.Block().Slot(),
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),
@@ -310,10 +308,11 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 				SyncCommitteeSignature: make([]byte, 96),
 			},
 		}
-	} else if currentEpoch < params.BeaconConfig().DenebForkEpoch {
+	case version.Capella:
 		m = &pb.LightClientUpdateCapella{
 			AttestedHeader: &pb.LightClientHeaderCapella{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       attestedBlock.Block().Slot(),
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),
@@ -362,10 +361,11 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 				SyncCommitteeSignature: make([]byte, 96),
 			},
 		}
-	} else if currentEpoch < params.BeaconConfig().ElectraForkEpoch {
+	case version.Deneb:
 		m = &pb.LightClientUpdateDeneb{
 			AttestedHeader: &pb.LightClientHeaderDeneb{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       attestedBlock.Block().Slot(),
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),
@@ -418,120 +418,65 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 				SyncCommitteeSignature: make([]byte, 96),
 			},
 		}
-	} else {
-		if attestedState.Version() >= version.Electra {
-			m = &pb.LightClientUpdateElectra{
-				AttestedHeader: &pb.LightClientHeaderDeneb{
-					Beacon: &pb.BeaconBlockHeader{
-						ParentRoot: make([]byte, 32),
-						StateRoot:  make([]byte, 32),
-						BodyRoot:   make([]byte, 32),
-					},
-					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
-						ParentHash:       make([]byte, fieldparams.RootLength),
-						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
-						StateRoot:        make([]byte, fieldparams.RootLength),
-						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
-						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
-						PrevRandao:       make([]byte, fieldparams.RootLength),
-						ExtraData:        make([]byte, 0),
-						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
-						BlockHash:        make([]byte, fieldparams.RootLength),
-						TransactionsRoot: make([]byte, fieldparams.RootLength),
-						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
-						GasLimit:         0,
-						GasUsed:          0,
-					},
-					ExecutionBranch: executionBranch,
+	case version.Electra, version.Fulu:
+		m = &pb.LightClientUpdateElectra{
+			AttestedHeader: &pb.LightClientHeaderDeneb{
+				Beacon: &pb.BeaconBlockHeader{
+					Slot:       attestedBlock.Block().Slot(),
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
 				},
-				NextSyncCommittee:       nextSyncCommittee,
-				NextSyncCommitteeBranch: nextSyncCommitteeBranch,
-				FinalityBranch:          finalityBranch,
-				FinalizedHeader: &pb.LightClientHeaderDeneb{
-					Beacon: &pb.BeaconBlockHeader{
-						ParentRoot: make([]byte, 32),
-						StateRoot:  make([]byte, 32),
-						BodyRoot:   make([]byte, 32),
-					},
-					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
-						ParentHash:       make([]byte, fieldparams.RootLength),
-						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
-						StateRoot:        make([]byte, fieldparams.RootLength),
-						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
-						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
-						PrevRandao:       make([]byte, fieldparams.RootLength),
-						ExtraData:        make([]byte, 0),
-						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
-						BlockHash:        make([]byte, fieldparams.RootLength),
-						TransactionsRoot: make([]byte, fieldparams.RootLength),
-						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
-						GasLimit:         0,
-						GasUsed:          0,
-					},
-					ExecutionBranch: executionBranch,
+				Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+					ParentHash:       make([]byte, fieldparams.RootLength),
+					FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+					StateRoot:        make([]byte, fieldparams.RootLength),
+					ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+					LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+					PrevRandao:       make([]byte, fieldparams.RootLength),
+					ExtraData:        make([]byte, 0),
+					BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+					BlockHash:        make([]byte, fieldparams.RootLength),
+					TransactionsRoot: make([]byte, fieldparams.RootLength),
+					WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+					GasLimit:         0,
+					GasUsed:          0,
 				},
-				SyncAggregate: &pb.SyncAggregate{
-					SyncCommitteeBits:      make([]byte, 64),
-					SyncCommitteeSignature: make([]byte, 96),
+				ExecutionBranch: executionBranch,
+			},
+			NextSyncCommittee:       nextSyncCommittee,
+			NextSyncCommitteeBranch: nextSyncCommitteeBranch,
+			FinalityBranch:          finalityBranch,
+			FinalizedHeader: &pb.LightClientHeaderDeneb{
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
 				},
-			}
-		} else {
-			m = &pb.LightClientUpdateDeneb{
-				AttestedHeader: &pb.LightClientHeaderDeneb{
-					Beacon: &pb.BeaconBlockHeader{
-						ParentRoot: make([]byte, 32),
-						StateRoot:  make([]byte, 32),
-						BodyRoot:   make([]byte, 32),
-					},
-					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
-						ParentHash:       make([]byte, fieldparams.RootLength),
-						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
-						StateRoot:        make([]byte, fieldparams.RootLength),
-						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
-						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
-						PrevRandao:       make([]byte, fieldparams.RootLength),
-						ExtraData:        make([]byte, 0),
-						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
-						BlockHash:        make([]byte, fieldparams.RootLength),
-						TransactionsRoot: make([]byte, fieldparams.RootLength),
-						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
-						GasLimit:         0,
-						GasUsed:          0,
-					},
-					ExecutionBranch: executionBranch,
+				Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+					ParentHash:       make([]byte, fieldparams.RootLength),
+					FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+					StateRoot:        make([]byte, fieldparams.RootLength),
+					ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+					LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+					PrevRandao:       make([]byte, fieldparams.RootLength),
+					ExtraData:        make([]byte, 0),
+					BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+					BlockHash:        make([]byte, fieldparams.RootLength),
+					TransactionsRoot: make([]byte, fieldparams.RootLength),
+					WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+					GasLimit:         0,
+					GasUsed:          0,
 				},
-				NextSyncCommittee:       nextSyncCommittee,
-				NextSyncCommitteeBranch: nextSyncCommitteeBranch,
-				FinalityBranch:          finalityBranch,
-				FinalizedHeader: &pb.LightClientHeaderDeneb{
-					Beacon: &pb.BeaconBlockHeader{
-						ParentRoot: make([]byte, 32),
-						StateRoot:  make([]byte, 32),
-						BodyRoot:   make([]byte, 32),
-					},
-					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
-						ParentHash:       make([]byte, fieldparams.RootLength),
-						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
-						StateRoot:        make([]byte, fieldparams.RootLength),
-						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
-						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
-						PrevRandao:       make([]byte, fieldparams.RootLength),
-						ExtraData:        make([]byte, 0),
-						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
-						BlockHash:        make([]byte, fieldparams.RootLength),
-						TransactionsRoot: make([]byte, fieldparams.RootLength),
-						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
-						GasLimit:         0,
-						GasUsed:          0,
-					},
-					ExecutionBranch: executionBranch,
-				},
-				SyncAggregate: &pb.SyncAggregate{
-					SyncCommitteeBits:      make([]byte, 64),
-					SyncCommitteeSignature: make([]byte, 96),
-				},
-			}
+				ExecutionBranch: executionBranch,
+			},
+			SyncAggregate: &pb.SyncAggregate{
+				SyncCommitteeBits:      make([]byte, 64),
+				SyncCommitteeSignature: make([]byte, 96),
+			},
 		}
+	default:
+		return nil, errors.Errorf("unsupported beacon chain version %s", version.String(attestedBlock.Version()))
 	}
 
 	return light_client.NewWrappedUpdate(m)
@@ -575,189 +520,52 @@ func ComputeWithdrawalsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 
 func BlockToLightClientHeader(
 	ctx context.Context,
-	currentSlot primitives.Slot,
-	block interfaces.ReadOnlySignedBeaconBlock,
+	attestedBlockVersion int, // this is the version that the light client header should be in, based on the attested block.
+	block interfaces.ReadOnlySignedBeaconBlock, // this block is either the attested block, or the finalized block.
+	// in case of the latter, we might need to upgrade it to the attested block's version.
 ) (interfaces.LightClientHeader, error) {
-	var m proto.Message
-	currentEpoch := slots.ToEpoch(currentSlot)
-	blockEpoch := slots.ToEpoch(block.Block().Slot())
-	parentRoot := block.Block().ParentRoot()
-	stateRoot := block.Block().StateRoot()
-	bodyRoot, err := block.Block().Body().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get body root")
+	if block.Version() > attestedBlockVersion {
+		return nil, errors.Errorf("block version %s is greater than attested block version %s", version.String(block.Version()), version.String(attestedBlockVersion))
 	}
 
-	if currentEpoch < params.BeaconConfig().CapellaForkEpoch {
+	beacon, err := makeBeaconBlockHeader(block)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not make beacon block header")
+	}
+
+	var m proto.Message
+	switch attestedBlockVersion {
+	case version.Altair, version.Bellatrix:
 		m = &pb.LightClientHeaderAltair{
-			Beacon: &pb.BeaconBlockHeader{
-				Slot:          block.Block().Slot(),
-				ProposerIndex: block.Block().ProposerIndex(),
-				ParentRoot:    parentRoot[:],
-				StateRoot:     stateRoot[:],
-				BodyRoot:      bodyRoot[:],
-			},
+			Beacon: beacon,
 		}
-	} else if currentEpoch < params.BeaconConfig().DenebForkEpoch {
-		var payloadHeader *enginev1.ExecutionPayloadHeaderCapella
-		var payloadProof [][]byte
-
-		if blockEpoch < params.BeaconConfig().CapellaForkEpoch {
-			var ok bool
-
-			p, err := execution.EmptyExecutionPayloadHeader(version.Capella)
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get payload header")
-			}
-			payloadHeader, ok = p.(*enginev1.ExecutionPayloadHeaderCapella)
-			if !ok {
-				return nil, fmt.Errorf("payload header type %T is not %T", p, &enginev1.ExecutionPayloadHeaderCapella{})
-			}
-			payloadProof = emptyPayloadProof()
-		} else {
-			payload, err := block.Block().Body().Execution()
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get execution payload")
-			}
-			transactionsRoot, err := ComputeTransactionsRoot(payload)
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get transactions root")
-			}
-			withdrawalsRoot, err := ComputeWithdrawalsRoot(payload)
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get withdrawals root")
-			}
-
-			payloadHeader = &enginev1.ExecutionPayloadHeaderCapella{
-				ParentHash:       payload.ParentHash(),
-				FeeRecipient:     payload.FeeRecipient(),
-				StateRoot:        payload.StateRoot(),
-				ReceiptsRoot:     payload.ReceiptsRoot(),
-				LogsBloom:        payload.LogsBloom(),
-				PrevRandao:       payload.PrevRandao(),
-				BlockNumber:      payload.BlockNumber(),
-				GasLimit:         payload.GasLimit(),
-				GasUsed:          payload.GasUsed(),
-				Timestamp:        payload.Timestamp(),
-				ExtraData:        payload.ExtraData(),
-				BaseFeePerGas:    payload.BaseFeePerGas(),
-				BlockHash:        payload.BlockHash(),
-				TransactionsRoot: transactionsRoot,
-				WithdrawalsRoot:  withdrawalsRoot,
-			}
-
-			payloadProof, err = blocks.PayloadProof(ctx, block.Block())
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get execution payload proof")
-			}
+	case version.Capella:
+		payloadHeader, payloadProof, err := makeExecutionAndProofCapella(ctx, block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not make execution payload header and proof")
 		}
-
 		m = &pb.LightClientHeaderCapella{
-			Beacon: &pb.BeaconBlockHeader{
-				Slot:          block.Block().Slot(),
-				ProposerIndex: block.Block().ProposerIndex(),
-				ParentRoot:    parentRoot[:],
-				StateRoot:     stateRoot[:],
-				BodyRoot:      bodyRoot[:],
-			},
+			Beacon:          beacon,
 			Execution:       payloadHeader,
 			ExecutionBranch: payloadProof,
 		}
-	} else {
-		var payloadHeader *enginev1.ExecutionPayloadHeaderDeneb
-		var payloadProof [][]byte
-
-		if blockEpoch < params.BeaconConfig().CapellaForkEpoch {
-			var ok bool
-
-			p, err := execution.EmptyExecutionPayloadHeader(version.Deneb)
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get payload header")
-			}
-			payloadHeader, ok = p.(*enginev1.ExecutionPayloadHeaderDeneb)
-			if !ok {
-				return nil, fmt.Errorf("payload header type %T is not %T", p, &enginev1.ExecutionPayloadHeaderDeneb{})
-			}
-			payloadProof = emptyPayloadProof()
-		} else {
-			payload, err := block.Block().Body().Execution()
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get execution payload")
-			}
-			transactionsRoot, err := ComputeTransactionsRoot(payload)
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get transactions root")
-			}
-			withdrawalsRoot, err := ComputeWithdrawalsRoot(payload)
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get withdrawals root")
-			}
-
-			var blobGasUsed uint64
-			var excessBlobGas uint64
-
-			if blockEpoch >= params.BeaconConfig().DenebForkEpoch {
-				blobGasUsed, err = payload.BlobGasUsed()
-				if err != nil {
-					return nil, errors.Wrap(err, "could not get blob gas used")
-				}
-				excessBlobGas, err = payload.ExcessBlobGas()
-				if err != nil {
-					return nil, errors.Wrap(err, "could not get excess blob gas")
-				}
-			}
-
-			payloadHeader = &enginev1.ExecutionPayloadHeaderDeneb{
-				ParentHash:       payload.ParentHash(),
-				FeeRecipient:     payload.FeeRecipient(),
-				StateRoot:        payload.StateRoot(),
-				ReceiptsRoot:     payload.ReceiptsRoot(),
-				LogsBloom:        payload.LogsBloom(),
-				PrevRandao:       payload.PrevRandao(),
-				BlockNumber:      payload.BlockNumber(),
-				GasLimit:         payload.GasLimit(),
-				GasUsed:          payload.GasUsed(),
-				Timestamp:        payload.Timestamp(),
-				ExtraData:        payload.ExtraData(),
-				BaseFeePerGas:    payload.BaseFeePerGas(),
-				BlockHash:        payload.BlockHash(),
-				TransactionsRoot: transactionsRoot,
-				WithdrawalsRoot:  withdrawalsRoot,
-				BlobGasUsed:      blobGasUsed,
-				ExcessBlobGas:    excessBlobGas,
-			}
-
-			payloadProof, err = blocks.PayloadProof(ctx, block.Block())
-			if err != nil {
-				return nil, errors.Wrap(err, "could not get execution payload proof")
-			}
+	case version.Deneb, version.Electra, version.Fulu:
+		payloadHeader, payloadProof, err := makeExecutionAndProofDeneb(ctx, block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not make execution payload header and proof")
 		}
-
 		m = &pb.LightClientHeaderDeneb{
-			Beacon: &pb.BeaconBlockHeader{
-				Slot:          block.Block().Slot(),
-				ProposerIndex: block.Block().ProposerIndex(),
-				ParentRoot:    parentRoot[:],
-				StateRoot:     stateRoot[:],
-				BodyRoot:      bodyRoot[:],
-			},
+			Beacon:          beacon,
 			Execution:       payloadHeader,
 			ExecutionBranch: payloadProof,
 		}
+	default:
+		return nil, fmt.Errorf("unsupported attested block version %s", version.String(attestedBlockVersion))
 	}
 
 	return light_client.NewWrappedHeader(m)
 }
 
-func emptyPayloadProof() [][]byte {
-	branch := interfaces.LightClientExecutionBranch{}
-	proof := make([][]byte, len(branch))
-	for i, b := range branch {
-		proof[i] = b[:]
-	}
-	return proof
-}
-
 func HasRelevantSyncCommittee(update interfaces.LightClientUpdate) (bool, error) {
 	if update.Version() >= version.Electra {
 		branch, err := update.NextSyncCommitteeBranchElectra()
@@ -909,7 +717,7 @@ func NewLightClientBootstrapFromBeaconState(
 		return nil, errors.Wrap(err, "could not create default light client bootstrap")
 	}
 
-	lightClientHeader, err := BlockToLightClientHeader(ctx, currentSlot, block)
+	lightClientHeader, err := BlockToLightClientHeader(ctx, state.Version(), block)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not convert block to light client header")
 	}
@@ -942,78 +750,6 @@ func NewLightClientBootstrapFromBeaconState(
 	return bootstrap, nil
 }
 
-func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.LightClientBootstrap, error) {
-	currentEpoch := slots.ToEpoch(currentSlot)
-	syncCommitteeSize := params.BeaconConfig().SyncCommitteeSize
-	pubKeys := make([][]byte, syncCommitteeSize)
-	for i := uint64(0); i < syncCommitteeSize; i++ {
-		pubKeys[i] = make([]byte, fieldparams.BLSPubkeyLength)
-	}
-	currentSyncCommittee := &pb.SyncCommittee{
-		Pubkeys:         pubKeys,
-		AggregatePubkey: make([]byte, fieldparams.BLSPubkeyLength),
-	}
-
-	var currentSyncCommitteeBranch [][]byte
-	if currentEpoch >= params.BeaconConfig().ElectraForkEpoch {
-		currentSyncCommitteeBranch = make([][]byte, fieldparams.SyncCommitteeBranchDepthElectra)
-	} else {
-		currentSyncCommitteeBranch = make([][]byte, fieldparams.SyncCommitteeBranchDepth)
-	}
-	for i := 0; i < len(currentSyncCommitteeBranch); i++ {
-		currentSyncCommitteeBranch[i] = make([]byte, fieldparams.RootLength)
-	}
-
-	executionBranch := make([][]byte, fieldparams.ExecutionBranchDepth)
-	for i := 0; i < fieldparams.ExecutionBranchDepth; i++ {
-		executionBranch[i] = make([]byte, 32)
-	}
-
-	// TODO: can this be based on the current epoch?
-	var m proto.Message
-	if currentEpoch < params.BeaconConfig().CapellaForkEpoch {
-		m = &pb.LightClientBootstrapAltair{
-			Header: &pb.LightClientHeaderAltair{
-				Beacon: &pb.BeaconBlockHeader{},
-			},
-			CurrentSyncCommittee:       currentSyncCommittee,
-			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
-		}
-	} else if currentEpoch < params.BeaconConfig().DenebForkEpoch {
-		m = &pb.LightClientBootstrapCapella{
-			Header: &pb.LightClientHeaderCapella{
-				Beacon:          &pb.BeaconBlockHeader{},
-				Execution:       &enginev1.ExecutionPayloadHeaderCapella{},
-				ExecutionBranch: executionBranch,
-			},
-			CurrentSyncCommittee:       currentSyncCommittee,
-			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
-		}
-	} else if currentEpoch < params.BeaconConfig().ElectraForkEpoch {
-		m = &pb.LightClientBootstrapDeneb{
-			Header: &pb.LightClientHeaderDeneb{
-				Beacon:          &pb.BeaconBlockHeader{},
-				Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
-				ExecutionBranch: executionBranch,
-			},
-			CurrentSyncCommittee:       currentSyncCommittee,
-			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
-		}
-	} else {
-		m = &pb.LightClientBootstrapElectra{
-			Header: &pb.LightClientHeaderDeneb{
-				Beacon:          &pb.BeaconBlockHeader{},
-				Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
-				ExecutionBranch: executionBranch,
-			},
-			CurrentSyncCommittee:       currentSyncCommittee,
-			CurrentSyncCommitteeBranch: currentSyncCommitteeBranch,
-		}
-	}
-
-	return light_client.NewWrappedBootstrap(m)
-}
-
 func UpdateHasSupermajority(syncAggregate *pb.SyncAggregate) bool {
 	maxActiveParticipants := syncAggregate.SyncCommitteeBits.Len()
 	numActiveParticipants := syncAggregate.SyncCommitteeBits.Count()

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

@@ -7,7 +7,6 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	light_client "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
@@ -547,7 +546,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
-			primitives.Slot(params.BeaconConfig().AltairForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+			version.Altair,
 			l.Block,
 		)
 		require.NoError(t, err)
@@ -570,7 +569,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
-			primitives.Slot(params.BeaconConfig().BellatrixForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+			version.Bellatrix,
 			l.Block,
 		)
 		require.NoError(t, err)
@@ -594,7 +593,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
-				primitives.Slot(params.BeaconConfig().CapellaForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+				version.Capella,
 				l.Block,
 			)
 			require.NoError(t, err)
@@ -655,7 +654,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
-				primitives.Slot(params.BeaconConfig().CapellaForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+				version.Capella,
 				l.Block,
 			)
 			require.NoError(t, err)
@@ -718,7 +717,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
-				primitives.Slot(params.BeaconConfig().DenebForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+				version.Deneb,
 				l.Block,
 			)
 			require.NoError(t, err)
@@ -787,7 +786,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
-				primitives.Slot(params.BeaconConfig().DenebForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+				version.Deneb,
 				l.Block,
 			)
 			require.NoError(t, err)
@@ -856,7 +855,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 		t.Run("Non-Blinded Beacon Block", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Electra)
 
-			header, err := lightClient.BlockToLightClientHeader(l.Ctx, l.State.Slot(), l.Block)
+			header, err := lightClient.BlockToLightClientHeader(l.Ctx, version.Electra, l.Block)
 			require.NoError(t, err)
 			require.NotNil(t, header, "header is nil")
 
@@ -921,7 +920,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 		t.Run("Blinded Beacon Block", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Electra, util.WithBlinded())
 
-			header, err := lightClient.BlockToLightClientHeader(l.Ctx, l.State.Slot(), l.Block)
+			header, err := lightClient.BlockToLightClientHeader(l.Ctx, version.Electra, l.Block)
 			require.NoError(t, err)
 			require.NotNil(t, header, "header is nil")
 
@@ -989,7 +988,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
-			primitives.Slot(params.BeaconConfig().CapellaForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+			version.Capella,
 			l.Block)
 		require.NoError(t, err)
 		require.NotNil(t, header, "header is nil")
@@ -1011,7 +1010,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
-			primitives.Slot(params.BeaconConfig().DenebForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+			version.Deneb,
 			l.Block)
 		require.NoError(t, err)
 		require.NotNil(t, header, "header is nil")
@@ -1034,7 +1033,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
-				primitives.Slot(params.BeaconConfig().DenebForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+				version.Deneb,
 				l.Block)
 			require.NoError(t, err)
 			require.NotNil(t, header, "header is nil")
@@ -1094,7 +1093,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
-				primitives.Slot(params.BeaconConfig().DenebForkEpoch)*params.BeaconConfig().SlotsPerEpoch,
+				version.Deneb,
 				l.Block)
 			require.NoError(t, err)
 			require.NotNil(t, header, "header is nil")
@@ -1180,14 +1179,13 @@ func createNonEmptyFinalityBranch() [][]byte {
 }
 
 func TestIsBetterUpdate(t *testing.T) {
-	config := params.BeaconConfig()
-	st, err := util.NewBeaconStateAltair()
+	blk, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockAltair())
 	require.NoError(t, err)
 
 	t.Run("new has supermajority but old doesn't", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1203,9 +1201,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("old has supermajority but new doesn't", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1221,9 +1219,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new doesn't have supermajority and newNumActiveParticipants is greater than oldNumActiveParticipants", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1239,9 +1237,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new doesn't have supermajority and newNumActiveParticipants is lesser than oldNumActiveParticipants", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1257,9 +1255,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new has relevant sync committee but old doesn't", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1296,9 +1294,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("old has relevant sync committee but new doesn't", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1335,9 +1333,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new has finality but old doesn't", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1378,9 +1376,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("old has finality but new doesn't", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1421,9 +1419,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new has finality and sync committee finality both but old doesn't have sync committee finality", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1482,9 +1480,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new has finality but doesn't have sync committee finality and old has sync committee finality", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1543,9 +1541,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new has more active participants than old", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1561,9 +1559,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new has less active participants than old", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1579,9 +1577,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new's attested header's slot is lesser than old's attested header's slot", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1640,9 +1638,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("new's attested header's slot is greater than old's attested header's slot", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1701,9 +1699,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("none of the above conditions are met and new signature's slot is less than old signature's slot", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{
@@ -1762,9 +1760,9 @@ func TestIsBetterUpdate(t *testing.T) {
 	})
 
 	t.Run("none of the above conditions are met and new signature's slot is greater than old signature's slot", func(t *testing.T) {
-		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(1), st)
+		oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
-		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(primitives.Slot(config.AltairForkEpoch*primitives.Epoch(config.SlotsPerEpoch)).Add(2), st)
+		newUpdate, err := lightClient.CreateDefaultLightClientUpdate(blk)
 		require.NoError(t, err)
 
 		oldUpdate.SetSyncAggregate(&pb.SyncAggregate{

beacon-chain/db/kv/lightclient.go

@@ -153,6 +153,13 @@ func decodeLightClientBootstrap(enc []byte) (interfaces.LightClientBootstrap, []
 		}
 		m = bootstrap
 		syncCommitteeHash = enc[len(altairKey) : len(altairKey)+32]
+	case hasBellatrixKey(enc):
+		bootstrap := &ethpb.LightClientBootstrapAltair{}
+		if err := bootstrap.UnmarshalSSZ(enc[len(bellatrixKey)+32:]); err != nil {
+			return nil, nil, errors.Wrap(err, "could not unmarshal Bellatrix light client bootstrap")
+		}
+		m = bootstrap
+		syncCommitteeHash = enc[len(bellatrixKey) : len(bellatrixKey)+32]
 	case hasCapellaKey(enc):
 		bootstrap := &ethpb.LightClientBootstrapCapella{}
 		if err := bootstrap.UnmarshalSSZ(enc[len(capellaKey)+32:]); err != nil {
@@ -265,6 +272,12 @@ func decodeLightClientUpdate(enc []byte) (interfaces.LightClientUpdate, error) {
 			return nil, errors.Wrap(err, "could not unmarshal Altair light client update")
 		}
 		m = update
+	case hasBellatrixKey(enc):
+		update := &ethpb.LightClientUpdateAltair{}
+		if err := update.UnmarshalSSZ(enc[len(bellatrixKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal Bellatrix light client update")
+		}
+		m = update
 	case hasCapellaKey(enc):
 		update := &ethpb.LightClientUpdateCapella{}
 		if err := update.UnmarshalSSZ(enc[len(capellaKey):]); err != nil {
@@ -297,6 +310,8 @@ func keyForLightClientUpdate(v int) ([]byte, error) {
 		return denebKey, nil
 	case version.Capella:
 		return capellaKey, nil
+	case version.Bellatrix:
+		return bellatrixKey, nil
 	case version.Altair:
 		return altairKey, nil
 	default:

beacon-chain/db/kv/lightclient_test.go

@@ -46,7 +46,21 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 		slot = primitives.Slot(config.AltairForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderAltair{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
+				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
+				ParentRoot:    sampleRoot,
+				StateRoot:     sampleRoot,
+				BodyRoot:      sampleRoot,
+			},
+		})
+		require.NoError(t, err)
+		st, err = util.NewBeaconState()
+		require.NoError(t, err)
+	case version.Bellatrix:
+		slot = primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderAltair{
+			Beacon: &pb.BeaconBlockHeader{
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -60,7 +74,7 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 		slot = primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderCapella{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -88,7 +102,7 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 		slot = primitives.Slot(config.DenebForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderDeneb{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -116,7 +130,7 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 		slot = primitives.Slot(config.ElectraForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderDeneb{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -144,7 +158,7 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 		slot = primitives.Slot(config.FuluForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderDeneb{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -192,10 +206,11 @@ func TestStore_LightClientUpdate_CanSaveRetrieve(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	cfg := params.BeaconConfig()
 	cfg.AltairForkEpoch = 0
-	cfg.CapellaForkEpoch = 1
-	cfg.DenebForkEpoch = 2
-	cfg.ElectraForkEpoch = 3
-	cfg.FuluForkEpoch = 3
+	cfg.BellatrixForkEpoch = 1
+	cfg.CapellaForkEpoch = 2
+	cfg.DenebForkEpoch = 3
+	cfg.ElectraForkEpoch = 4
+	cfg.FuluForkEpoch = 5
 	params.OverrideBeaconConfig(cfg)
 
 	db := setupDB(t)
@@ -213,6 +228,18 @@ func TestStore_LightClientUpdate_CanSaveRetrieve(t *testing.T) {
 		require.NoError(t, err)
 		require.DeepEqual(t, update, retrievedUpdate, "retrieved update does not match saved update")
 	})
+	t.Run("Bellatrix", func(t *testing.T) {
+		update, err := createUpdate(t, version.Bellatrix)
+		require.NoError(t, err)
+		period := uint64(1)
+
+		err = db.SaveLightClientUpdate(ctx, period, update)
+		require.NoError(t, err)
+
+		retrievedUpdate, err := db.LightClientUpdate(ctx, period)
+		require.NoError(t, err)
+		require.DeepEqual(t, update, retrievedUpdate, "retrieved update does not match saved update")
+	})
 	t.Run("Capella", func(t *testing.T) {
 		update, err := createUpdate(t, version.Capella)
 		require.NoError(t, err)
@@ -242,17 +269,6 @@ func TestStore_LightClientUpdate_CanSaveRetrieve(t *testing.T) {
 		err = db.SaveLightClientUpdate(ctx, period, update)
 		require.NoError(t, err)
 
-		retrievedUpdate, err := db.LightClientUpdate(ctx, period)
-		require.NoError(t, err)
-		require.DeepEqual(t, update, retrievedUpdate, "retrieved update does not match saved update")
-	})
-	t.Run("Fulu", func(t *testing.T) {
-		update, err := createUpdate(t, version.Fulu)
-		require.NoError(t, err)
-		period := uint64(1)
-		err = db.SaveLightClientUpdate(ctx, period, update)
-		require.NoError(t, err)
-
 		retrievedUpdate, err := db.LightClientUpdate(ctx, period)
 		require.NoError(t, err)
 		require.DeepEqual(t, update, retrievedUpdate, "retrieved update does not match saved update")
@@ -584,9 +600,10 @@ func TestStore_LightClientBootstrap_CanSaveRetrieve(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	cfg := params.BeaconConfig()
 	cfg.AltairForkEpoch = 0
-	cfg.CapellaForkEpoch = 1
-	cfg.DenebForkEpoch = 2
-	cfg.ElectraForkEpoch = 3
+	cfg.BellatrixForkEpoch = 1
+	cfg.CapellaForkEpoch = 2
+	cfg.DenebForkEpoch = 3
+	cfg.ElectraForkEpoch = 4
 	cfg.EpochsPerSyncCommitteePeriod = 1
 	params.OverrideBeaconConfig(cfg)
 
@@ -839,6 +856,7 @@ func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.
 		m = &pb.LightClientBootstrapAltair{
 			Header: &pb.LightClientHeaderAltair{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       currentSlot,
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),
@@ -851,6 +869,7 @@ func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.
 		m = &pb.LightClientBootstrapCapella{
 			Header: &pb.LightClientHeaderCapella{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       currentSlot,
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),
@@ -877,6 +896,7 @@ func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.
 		m = &pb.LightClientBootstrapDeneb{
 			Header: &pb.LightClientHeaderDeneb{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       currentSlot,
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),
@@ -905,6 +925,7 @@ func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.
 		m = &pb.LightClientBootstrapElectra{
 			Header: &pb.LightClientHeaderDeneb{
 				Beacon: &pb.BeaconBlockHeader{
+					Slot:       currentSlot,
 					ParentRoot: make([]byte, 32),
 					StateRoot:  make([]byte, 32),
 					BodyRoot:   make([]byte, 32),

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

@@ -42,9 +42,9 @@ go_test(
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
-        "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/light-client:go_default_library",
         "//consensus-types/primitives:go_default_library",

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

@@ -15,9 +15,9 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	dbtesting "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	light_client "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -175,7 +175,7 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 		var respHeader structs.LightClientHeader
 		err = json.Unmarshal(resp.Data.Header, &respHeader)
 		require.NoError(t, err)
-		require.Equal(t, "altair", resp.Version)
+		require.Equal(t, "bellatrix", resp.Version)
 
 		blockHeader, err := l.Block.Header()
 		require.NoError(t, err)
@@ -454,8 +454,9 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 	config := params.BeaconConfig()
 	config.EpochsPerSyncCommitteePeriod = 1
 	config.AltairForkEpoch = 0
-	config.CapellaForkEpoch = 1
-	config.DenebForkEpoch = 2
+	config.BellatrixForkEpoch = 1
+	config.CapellaForkEpoch = 2
+	config.DenebForkEpoch = 3
 	params.OverrideBeaconConfig(config)
 
 	t.Run("altair", func(t *testing.T) {
@@ -537,6 +538,85 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		require.DeepEqual(t, resp.AttestedHeader, update.AttestedHeader().Proto())
 	})
 
+	t.Run("bellatrix", func(t *testing.T) {
+		slot := primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+
+		st, err := util.NewBeaconStateBellatrix()
+		require.NoError(t, err)
+		err = st.SetSlot(slot)
+		require.NoError(t, err)
+
+		db := dbtesting.SetupDB(t)
+
+		updatePeriod := uint64(slot.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch)))
+
+		update, err := createUpdate(t, version.Bellatrix)
+		require.NoError(t, err)
+		err = db.SaveLightClientUpdate(ctx, updatePeriod, update)
+		require.NoError(t, err)
+
+		mockChainService := &mock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher: mockChainService,
+			BeaconDB:    db,
+		}
+		startPeriod := slot.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+		url := fmt.Sprintf("http://foo.com/?count=1&start_period=%d", startPeriod)
+		request := httptest.NewRequest("GET", url, nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetLightClientUpdatesByRange(writer, request)
+
+		require.Equal(t, http.StatusOK, writer.Code)
+		var resp structs.LightClientUpdatesByRangeResponse
+		err = json.Unmarshal(writer.Body.Bytes(), &resp.Updates)
+		require.NoError(t, err)
+		require.Equal(t, 1, len(resp.Updates))
+		require.Equal(t, "bellatrix", resp.Updates[0].Version)
+		updateJson, err := structs.LightClientUpdateFromConsensus(update)
+		require.NoError(t, err)
+		require.DeepEqual(t, updateJson, resp.Updates[0].Data)
+	})
+
+	t.Run("bellatrix ssz", func(t *testing.T) {
+		slot := primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+
+		st, err := util.NewBeaconStateBellatrix()
+		require.NoError(t, err)
+		err = st.SetSlot(slot)
+		require.NoError(t, err)
+
+		db := dbtesting.SetupDB(t)
+
+		updatePeriod := uint64(slot.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch)))
+
+		update, err := createUpdate(t, version.Bellatrix)
+		require.NoError(t, err)
+		err = db.SaveLightClientUpdate(ctx, updatePeriod, update)
+		require.NoError(t, err)
+
+		mockChainService := &mock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher: mockChainService,
+			BeaconDB:    db,
+		}
+		startPeriod := slot.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+		url := fmt.Sprintf("http://foo.com/?count=1&start_period=%d", startPeriod)
+		request := httptest.NewRequest("GET", url, nil)
+		request.Header.Add("Accept", "application/octet-stream")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetLightClientUpdatesByRange(writer, request)
+
+		require.Equal(t, http.StatusOK, writer.Code)
+		var resp pb.LightClientUpdateAltair
+		err = resp.UnmarshalSSZ(writer.Body.Bytes()[12:]) // skip the length and fork digest prefixes
+		require.NoError(t, err)
+		require.DeepEqual(t, resp.AttestedHeader, update.AttestedHeader().Proto())
+	})
+
 	t.Run("capella", func(t *testing.T) {
 		slot := primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 
@@ -1013,13 +1093,13 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		}
 	})
 
-	t.Run("multiple forks - altair, capella", func(t *testing.T) {
-		slotCapella := primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+	t.Run("multiple forks - altair, bellatrix", func(t *testing.T) {
+		slotBellatrix := primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		slotAltair := primitives.Slot(config.AltairForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 
-		st, err := util.NewBeaconStateAltair()
+		st, err := util.NewBeaconStateBellatrix()
 		require.NoError(t, err)
-		headSlot := slotCapella.Add(1)
+		headSlot := slotBellatrix.Add(1)
 		err = st.SetSlot(headSlot)
 		require.NoError(t, err)
 
@@ -1035,9 +1115,9 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[0])
 		require.NoError(t, err)
 
-		updatePeriod = slotCapella.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+		updatePeriod = slotBellatrix.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
 
-		updates[1], err = createUpdate(t, version.Capella)
+		updates[1], err = createUpdate(t, version.Bellatrix)
 		require.NoError(t, err)
 
 		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[1])
@@ -1065,7 +1145,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 			if i < 1 {
 				require.Equal(t, "altair", resp.Updates[i].Version)
 			} else {
-				require.Equal(t, "capella", resp.Updates[i].Version)
+				require.Equal(t, "bellatrix", resp.Updates[i].Version)
 			}
 			updateJson, err := structs.LightClientUpdateFromConsensus(update)
 			require.NoError(t, err)
@@ -1073,13 +1153,13 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		}
 	})
 
-	t.Run("multiple forks - altair, capella - ssz", func(t *testing.T) {
-		slotCapella := primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+	t.Run("multiple forks - altair, bellatrix - ssz", func(t *testing.T) {
+		slotBellatrix := primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		slotAltair := primitives.Slot(config.AltairForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 
-		st, err := util.NewBeaconStateAltair()
+		st, err := util.NewBeaconStateBellatrix()
 		require.NoError(t, err)
-		headSlot := slotCapella.Add(1)
+		headSlot := slotBellatrix.Add(1)
 		err = st.SetSlot(headSlot)
 		require.NoError(t, err)
 
@@ -1095,6 +1175,68 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[0])
 		require.NoError(t, err)
 
+		updatePeriod = slotBellatrix.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+
+		updates[1], err = createUpdate(t, version.Bellatrix)
+		require.NoError(t, err)
+
+		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[1])
+		require.NoError(t, err)
+
+		mockChainService := &mock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher: mockChainService,
+			BeaconDB:    db,
+		}
+		startPeriod := 0
+		url := fmt.Sprintf("http://foo.com/?count=100&start_period=%d", startPeriod)
+		request := httptest.NewRequest("GET", url, nil)
+		request.Header.Add("Accept", "application/octet-stream")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetLightClientUpdatesByRange(writer, request)
+
+		require.Equal(t, http.StatusOK, writer.Code)
+
+		offset := 0
+		updateLen := int(ssz.UnmarshallUint64(writer.Body.Bytes()[offset:offset+8]) - 4)
+		offset += 12
+		var resp pb.LightClientUpdateAltair
+		err = resp.UnmarshalSSZ(writer.Body.Bytes()[offset : offset+updateLen])
+		require.NoError(t, err)
+		require.DeepEqual(t, resp.AttestedHeader, updates[0].AttestedHeader().Proto())
+		offset += updateLen
+		updateLen = int(ssz.UnmarshallUint64(writer.Body.Bytes()[offset:offset+8]) - 4)
+		offset += 12
+		var resp1 pb.LightClientUpdateAltair
+		err = resp1.UnmarshalSSZ(writer.Body.Bytes()[offset : offset+updateLen])
+		require.NoError(t, err)
+		require.DeepEqual(t, resp1.AttestedHeader, updates[1].AttestedHeader().Proto())
+	})
+
+	t.Run("multiple forks - bellatrix, capella", func(t *testing.T) {
+		slotCapella := primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+		slotBellatrix := primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+
+		st, err := util.NewBeaconStateCapella()
+		require.NoError(t, err)
+		headSlot := slotCapella.Add(1)
+		err = st.SetSlot(headSlot)
+		require.NoError(t, err)
+
+		db := dbtesting.SetupDB(t)
+
+		updates := make([]interfaces.LightClientUpdate, 2)
+
+		updatePeriod := slotBellatrix.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+
+		updates[0], err = createUpdate(t, version.Bellatrix)
+		require.NoError(t, err)
+
+		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[0])
+		require.NoError(t, err)
+
 		updatePeriod = slotCapella.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
 
 		updates[1], err = createUpdate(t, version.Capella)
@@ -1108,7 +1250,67 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 			HeadFetcher: mockChainService,
 			BeaconDB:    db,
 		}
-		startPeriod := 0
+		startPeriod := slotBellatrix.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+		url := fmt.Sprintf("http://foo.com/?count=100&start_period=%d", startPeriod)
+		request := httptest.NewRequest("GET", url, nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetLightClientUpdatesByRange(writer, request)
+
+		require.Equal(t, http.StatusOK, writer.Code)
+		var resp structs.LightClientUpdatesByRangeResponse
+		err = json.Unmarshal(writer.Body.Bytes(), &resp.Updates)
+		require.NoError(t, err)
+		require.Equal(t, 2, len(resp.Updates))
+		for i, update := range updates {
+			if i < 1 {
+				require.Equal(t, "bellatrix", resp.Updates[i].Version)
+			} else {
+				require.Equal(t, "capella", resp.Updates[i].Version)
+			}
+			updateJson, err := structs.LightClientUpdateFromConsensus(update)
+			require.NoError(t, err)
+			require.DeepEqual(t, updateJson, resp.Updates[i].Data)
+		}
+	})
+
+	t.Run("multiple forks - bellatrix, capella - ssz", func(t *testing.T) {
+		slotCapella := primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+		slotBellatrix := primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+
+		st, err := util.NewBeaconStateCapella()
+		require.NoError(t, err)
+		headSlot := slotCapella.Add(1)
+		err = st.SetSlot(headSlot)
+		require.NoError(t, err)
+
+		db := dbtesting.SetupDB(t)
+
+		updates := make([]interfaces.LightClientUpdate, 2)
+
+		updatePeriod := slotBellatrix.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+
+		updates[0], err = createUpdate(t, version.Bellatrix)
+		require.NoError(t, err)
+
+		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[0])
+		require.NoError(t, err)
+
+		updatePeriod = slotCapella.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
+
+		updates[1], err = createUpdate(t, version.Capella)
+		require.NoError(t, err)
+
+		err = db.SaveLightClientUpdate(ctx, uint64(updatePeriod), updates[1])
+		require.NoError(t, err)
+
+		mockChainService := &mock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher: mockChainService,
+			BeaconDB:    db,
+		}
+		startPeriod := slotBellatrix.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
 		url := fmt.Sprintf("http://foo.com/?count=100&start_period=%d", startPeriod)
 		request := httptest.NewRequest("GET", url, nil)
 		request.Header.Add("Accept", "application/octet-stream")
@@ -1170,7 +1372,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 			HeadFetcher: mockChainService,
 			BeaconDB:    db,
 		}
-		startPeriod := 1
+		startPeriod := slotCapella.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
 		url := fmt.Sprintf("http://foo.com/?count=100&start_period=%d", startPeriod)
 		request := httptest.NewRequest("GET", url, nil)
 		writer := httptest.NewRecorder()
@@ -1230,7 +1432,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 			HeadFetcher: mockChainService,
 			BeaconDB:    db,
 		}
-		startPeriod := 1
+		startPeriod := slotCapella.Div(uint64(config.EpochsPerSyncCommitteePeriod)).Div(uint64(config.SlotsPerEpoch))
 		url := fmt.Sprintf("http://foo.com/?count=100&start_period=%d", startPeriod)
 		request := httptest.NewRequest("GET", url, nil)
 		request.Header.Add("Accept", "application/octet-stream")
@@ -1522,11 +1724,7 @@ func TestLightClientHandler_GetLightClientFinalityUpdate(t *testing.T) {
 			var resp structs.LightClientFinalityUpdateResponse
 			err = json.Unmarshal(writer.Body.Bytes(), &resp)
 			require.NoError(t, err)
-			if testVersion == version.Bellatrix {
-				require.Equal(t, version.String(version.Altair), resp.Version)
-			} else {
-				require.Equal(t, version.String(testVersion), resp.Version)
-			}
+			require.Equal(t, version.String(testVersion), resp.Version)
 			require.DeepEqual(t, data, resp.Data)
 		})
 
@@ -1606,13 +1804,7 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 			var resp structs.LightClientOptimisticUpdateResponse
 			err = json.Unmarshal(writer.Body.Bytes(), &resp)
 			require.NoError(t, err)
-			if testVersion == version.Bellatrix {
-				require.Equal(t, version.String(version.Altair), resp.Version)
-			} else if testVersion == version.Electra {
-				require.Equal(t, version.String(version.Deneb), resp.Version)
-			} else {
-				require.Equal(t, version.String(testVersion), resp.Version)
-			}
+			require.Equal(t, version.String(testVersion), resp.Version)
 			require.DeepEqual(t, data, resp.Data)
 		})
 
@@ -1661,7 +1853,7 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 	config := params.BeaconConfig()
 	var slot primitives.Slot
 	var header interfaces.LightClientHeader
-	var st state.BeaconState
+	var blk interfaces.ReadOnlySignedBeaconBlock
 	var err error
 
 	sampleRoot := make([]byte, 32)
@@ -1682,7 +1874,7 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 		slot = primitives.Slot(config.AltairForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderAltair{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -1690,13 +1882,27 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 			},
 		})
 		require.NoError(t, err)
-		st, err = util.NewBeaconStateAltair()
+		blk, err = blocks.NewSignedBeaconBlock(util.NewBeaconBlockAltair())
+		require.NoError(t, err)
+	case version.Bellatrix:
+		slot = primitives.Slot(config.BellatrixForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
+		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderAltair{
+			Beacon: &pb.BeaconBlockHeader{
+				Slot:          slot,
+				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
+				ParentRoot:    sampleRoot,
+				StateRoot:     sampleRoot,
+				BodyRoot:      sampleRoot,
+			},
+		})
+		require.NoError(t, err)
+		blk, err = blocks.NewSignedBeaconBlock(util.NewBeaconBlockBellatrix())
 		require.NoError(t, err)
 	case version.Capella:
 		slot = primitives.Slot(config.CapellaForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderCapella{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -1718,13 +1924,13 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 			ExecutionBranch: sampleExecutionBranch,
 		})
 		require.NoError(t, err)
-		st, err = util.NewBeaconStateCapella()
+		blk, err = blocks.NewSignedBeaconBlock(util.NewBeaconBlockCapella())
 		require.NoError(t, err)
 	case version.Deneb:
 		slot = primitives.Slot(config.DenebForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderDeneb{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -1746,13 +1952,13 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 			ExecutionBranch: sampleExecutionBranch,
 		})
 		require.NoError(t, err)
-		st, err = util.NewBeaconStateDeneb()
+		blk, err = blocks.NewSignedBeaconBlock(util.NewBeaconBlockDeneb())
 		require.NoError(t, err)
 	case version.Electra:
 		slot = primitives.Slot(config.ElectraForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderDeneb{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -1774,13 +1980,13 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 			ExecutionBranch: sampleExecutionBranch,
 		})
 		require.NoError(t, err)
-		st, err = util.NewBeaconStateElectra()
+		blk, err = blocks.NewSignedBeaconBlock(util.NewBeaconBlockElectra())
 		require.NoError(t, err)
 	case version.Fulu:
 		slot = primitives.Slot(config.FuluForkEpoch * primitives.Epoch(config.SlotsPerEpoch)).Add(1)
 		header, err = light_client.NewWrappedHeader(&pb.LightClientHeaderDeneb{
 			Beacon: &pb.BeaconBlockHeader{
-				Slot:          1,
+				Slot:          slot,
 				ProposerIndex: primitives.ValidatorIndex(rand.Int()),
 				ParentRoot:    sampleRoot,
 				StateRoot:     sampleRoot,
@@ -1802,13 +2008,13 @@ func createUpdate(t *testing.T, v int) (interfaces.LightClientUpdate, error) {
 			ExecutionBranch: sampleExecutionBranch,
 		})
 		require.NoError(t, err)
-		st, err = util.NewBeaconStateFulu()
+		blk, err = blocks.NewSignedBeaconBlock(util.NewBeaconBlockFulu())
 		require.NoError(t, err)
 	default:
 		return nil, fmt.Errorf("unsupported version %s", version.String(v))
 	}
 
-	update, err := lightclient.CreateDefaultLightClientUpdate(slot, st)
+	update, err := lightclient.CreateDefaultLightClientUpdate(blk)
 	require.NoError(t, err)
 	update.SetSignatureSlot(slot - 1)
 	syncCommitteeBits := make([]byte, 64)

changelog/bastin_fix-lc-versioning.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Fixed the versioning bug for light client data types in the Beacon API.

consensus-types/light-client/bootstrap.go

@@ -8,6 +8,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -83,7 +84,7 @@ func (h *bootstrapAltair) SizeSSZ() int {
 }
 
 func (h *bootstrapAltair) Version() int {
-	return version.Altair
+	return slots.ToForkVersion(h.header.Beacon().Slot)
 }
 
 func (h *bootstrapAltair) Proto() proto.Message {
@@ -188,7 +189,7 @@ func (h *bootstrapCapella) SizeSSZ() int {
 }
 
 func (h *bootstrapCapella) Version() int {
-	return version.Capella
+	return slots.ToForkVersion(h.header.Beacon().Slot)
 }
 
 func (h *bootstrapCapella) Proto() proto.Message {
@@ -293,7 +294,7 @@ func (h *bootstrapDeneb) SizeSSZ() int {
 }
 
 func (h *bootstrapDeneb) Version() int {
-	return version.Deneb
+	return slots.ToForkVersion(h.header.Beacon().Slot)
 }
 
 func (h *bootstrapDeneb) Proto() proto.Message {
@@ -398,7 +399,7 @@ func (h *bootstrapElectra) SizeSSZ() int {
 }
 
 func (h *bootstrapElectra) Version() int {
-	return version.Electra
+	return slots.ToForkVersion(h.header.Beacon().Slot)
 }
 
 func (h *bootstrapElectra) Proto() proto.Message {

consensus-types/light-client/finality_update.go

@@ -8,7 +8,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -174,7 +174,7 @@ func (u *finalityUpdateAltair) Proto() proto.Message {
 }
 
 func (u *finalityUpdateAltair) Version() int {
-	return version.Altair
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *finalityUpdateAltair) AttestedHeader() interfaces.LightClientHeader {
@@ -286,7 +286,7 @@ func (u *finalityUpdateCapella) Proto() proto.Message {
 }
 
 func (u *finalityUpdateCapella) Version() int {
-	return version.Capella
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *finalityUpdateCapella) AttestedHeader() interfaces.LightClientHeader {
@@ -398,7 +398,7 @@ func (u *finalityUpdateDeneb) Proto() proto.Message {
 }
 
 func (u *finalityUpdateDeneb) Version() int {
-	return version.Deneb
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *finalityUpdateDeneb) AttestedHeader() interfaces.LightClientHeader {
@@ -511,7 +511,7 @@ func (u *finalityUpdateElectra) Proto() proto.Message {
 }
 
 func (u *finalityUpdateElectra) Version() int {
-	return version.Electra
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *finalityUpdateElectra) AttestedHeader() interfaces.LightClientHeader {

consensus-types/light-client/optimistic_update.go

@@ -7,7 +7,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -139,7 +139,7 @@ func (u *optimisticUpdateAltair) Proto() proto.Message {
 }
 
 func (u *optimisticUpdateAltair) Version() int {
-	return version.Altair
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *optimisticUpdateAltair) AttestedHeader() interfaces.LightClientHeader {
@@ -223,7 +223,7 @@ func (u *optimisticUpdateCapella) Proto() proto.Message {
 }
 
 func (u *optimisticUpdateCapella) Version() int {
-	return version.Capella
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *optimisticUpdateCapella) AttestedHeader() interfaces.LightClientHeader {
@@ -307,7 +307,7 @@ func (u *optimisticUpdateDeneb) Proto() proto.Message {
 }
 
 func (u *optimisticUpdateDeneb) Version() int {
-	return version.Deneb
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *optimisticUpdateDeneb) AttestedHeader() interfaces.LightClientHeader {

consensus-types/light-client/update.go

@@ -9,6 +9,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -105,7 +106,7 @@ func (u *updateAltair) Proto() proto.Message {
 }
 
 func (u *updateAltair) Version() int {
-	return version.Altair
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *updateAltair) AttestedHeader() interfaces.LightClientHeader {
@@ -272,7 +273,7 @@ func (u *updateCapella) Proto() proto.Message {
 }
 
 func (u *updateCapella) Version() int {
-	return version.Capella
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *updateCapella) AttestedHeader() interfaces.LightClientHeader {
@@ -439,7 +440,7 @@ func (u *updateDeneb) Proto() proto.Message {
 }
 
 func (u *updateDeneb) Version() int {
-	return version.Deneb
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *updateDeneb) AttestedHeader() interfaces.LightClientHeader {
@@ -607,7 +608,7 @@ func (u *updateElectra) Proto() proto.Message {
 }
 
 func (u *updateElectra) Version() int {
-	return version.Electra
+	return slots.ToForkVersion(u.attestedHeader.Beacon().Slot)
 }
 
 func (u *updateElectra) AttestedHeader() interfaces.LightClientHeader {

testing/spectest/minimal/electra__light_client__single_merkle_proof_test.go

@@ -7,6 +7,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/spectest/shared/common/light_client"
 )
 
-func TestMainnet_Electra_LightClient_SingleMerkleProof(t *testing.T) {
+func TestMinimal_Electra_LightClient_SingleMerkleProof(t *testing.T) {
 	light_client.RunLightClientSingleMerkleProofTests(t, "minimal", version.Electra)
 }

testing/spectest/minimal/electra__light_client__update_ranking_test.go

@@ -7,6 +7,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/spectest/shared/common/light_client"
 )
 
-func TestMainnet_Electra_LightClient_UpdateRanking(t *testing.T) {
+func TestMinimal_Electra_LightClient_UpdateRanking(t *testing.T) {
 	light_client.RunLightClientUpdateRankingTests(t, "minimal", version.Electra)
 }

testing/spectest/shared/common/light_client/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/light-client:go_default_library",
         "//container/trie:go_default_library",

testing/spectest/shared/common/light_client/update_ranking.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	lightclienttypes "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -20,6 +21,24 @@ import (
 // RunLightClientUpdateRankingTests executes "light_client/update_ranking/pyspec_tests/update_ranking" tests.
 func RunLightClientUpdateRankingTests(t *testing.T, config string, v int) {
 	require.NoError(t, utils.SetConfig(t, config))
+	if v >= version.Altair {
+		params.BeaconConfig().AltairForkEpoch = 0
+	}
+	if v >= version.Bellatrix {
+		params.BeaconConfig().BellatrixForkEpoch = 0
+	}
+	if v >= version.Capella {
+		params.BeaconConfig().CapellaForkEpoch = 0
+	}
+	if v >= version.Deneb {
+		params.BeaconConfig().DenebForkEpoch = 0
+	}
+	if v >= version.Electra {
+		params.BeaconConfig().ElectraForkEpoch = 0
+	}
+	if v >= version.Fulu {
+		params.BeaconConfig().FuluForkEpoch = 0
+	}
 
 	_, testsFolderPath := utils.TestFolders(t, config, version.String(v), "light_client/update_ranking/pyspec_tests/")
 	testTypes, err := util.BazelListDirectories(testsFolderPath)