implements the proposer lookahead api (#15525)

* implements the proposer lookahead api

* radek's feedback

api/server/structs/endpoints_beacon.go

@@ -283,3 +283,10 @@ type GetPendingPartialWithdrawalsResponse struct {
 	Finalized           bool                        `json:"finalized"`
 	Data                []*PendingPartialWithdrawal `json:"data"`
 }
+
+type GetProposerLookaheadResponse struct {
+	Version             string   `json:"version"`
+	ExecutionOptimistic bool     `json:"execution_optimistic"`
+	Finalized           bool     `json:"finalized"`
+	Data                []string `json:"data"` // validator indexes
+}

beacon-chain/rpc/endpoints.go

@@ -985,6 +985,16 @@ func (s *Service) beaconEndpoints(
 			handler: server.GetPendingPartialWithdrawals,
 			methods: []string{http.MethodGet},
 		},
+		{
+			template: "/eth/v1/beacon/states/{state_id}/proposer_lookahead",
+			name:     namespace + ".GetProposerLookahead",
+			middleware: []middleware.Middleware{
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType, api.OctetStreamMediaType}),
+				middleware.AcceptEncodingHeaderHandler(),
+			},
+			handler: server.GetProposerLookahead,
+			methods: []string{http.MethodGet},
+		},
 	}
 }
 

beacon-chain/rpc/endpoints_test.go

@@ -32,6 +32,7 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v1/beacon/states/{state_id}/pending_deposits":            {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/pending_partial_withdrawals": {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/pending_consolidations":      {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/proposer_lookahead":          {http.MethodGet},
 		"/eth/v1/beacon/headers":                                       {http.MethodGet},
 		"/eth/v1/beacon/headers/{block_id}":                            {http.MethodGet},
 		"/eth/v1/beacon/blinded_blocks":                                {http.MethodPost},

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

@@ -123,6 +123,7 @@ go_test(
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
         "@com_github_stretchr_testify//mock:go_default_library",

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

@@ -1790,6 +1790,63 @@ func (s *Server) GetPendingPartialWithdrawals(w http.ResponseWriter, r *http.Req
 	}
 }
 
+func (s *Server) GetProposerLookahead(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.GetProposerLookahead")
+	defer span.End()
+
+	stateId := r.PathValue("state_id")
+	if stateId == "" {
+		httputil.HandleError(w, "state_id is required in URL params", http.StatusBadRequest)
+		return
+	}
+	st, err := s.Stater.State(ctx, []byte(stateId))
+	if err != nil {
+		shared.WriteStateFetchError(w, err)
+		return
+	}
+	if st.Version() < version.Fulu {
+		httputil.HandleError(w, "state_id is prior to fulu", http.StatusBadRequest)
+		return
+	}
+	pl, err := st.ProposerLookahead()
+	if err != nil {
+		httputil.HandleError(w, "Could not get proposer look ahead: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set(api.VersionHeader, version.String(st.Version()))
+	if httputil.RespondWithSsz(r) {
+		sszLen := (*primitives.ValidatorIndex)(nil).SizeSSZ()
+		sszData := make([]byte, len(pl)*sszLen)
+		for i, idx := range pl {
+			copy(sszData[i*sszLen:(i+1)*sszLen], ssz.MarshalUint64([]byte{}, uint64(idx)))
+		}
+		httputil.WriteSsz(w, sszData)
+	} else {
+		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
+		if err != nil {
+			httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
+		if err != nil {
+			httputil.HandleError(w, "Could not calculate root of latest block header: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		isFinalized := s.FinalizationFetcher.IsFinalized(ctx, blockRoot)
+		vi := make([]string, len(pl))
+		for i, v := range pl {
+			vi[i] = strconv.FormatUint(uint64(v), 10)
+		}
+		resp := structs.GetProposerLookaheadResponse{
+			Version:             version.String(st.Version()),
+			ExecutionOptimistic: isOptimistic,
+			Finalized:           isFinalized,
+			Data:                vi,
+		}
+		httputil.WriteJson(w, resp)
+	}
+}
+
 // SerializeItems serializes a slice of items, each of which implements the MarshalSSZ method,
 // into a single byte array.
 func serializeItems[T interface{ MarshalSSZ() ([]byte, error) }](items []T) ([]byte, error) {

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

@@ -43,6 +43,7 @@ import (
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
+	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/prysmaticlabs/go-bitfield"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"github.com/stretchr/testify/mock"
@@ -5363,3 +5364,190 @@ func TestGetPendingPartialWithdrawals(t *testing.T) {
 		require.Equal(t, true, resp.Finalized)
 	})
 }
+
+func TestGetProposerLookahead(t *testing.T) {
+	numValidators := 50
+	// Create a Fulu state with proposer lookahead data
+	st, _ := util.DeterministicGenesisStateFulu(t, uint64(numValidators))
+	lookaheadSize := int(params.BeaconConfig().MinSeedLookahead+1) * int(params.BeaconConfig().SlotsPerEpoch)
+	lookahead := make([]primitives.ValidatorIndex, lookaheadSize)
+	for i := 0; i < lookaheadSize; i++ {
+		lookahead[i] = primitives.ValidatorIndex(i % numValidators) // Cycle through validators
+	}
+
+	require.NoError(t, st.SetProposerLookahead(lookahead))
+
+	chainService := &chainMock.ChainService{
+		Optimistic:     false,
+		FinalizedRoots: map[[32]byte]bool{},
+	}
+	server := &Server{
+		Stater: &testutil.MockStater{
+			BeaconState: st,
+		},
+		OptimisticModeFetcher: chainService,
+		FinalizationFetcher:   chainService,
+	}
+
+	t.Run("json response", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+		require.Equal(t, "fulu", rec.Header().Get(api.VersionHeader))
+
+		var resp structs.GetProposerLookaheadResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+
+		expectedVersion := version.String(st.Version())
+		require.Equal(t, expectedVersion, resp.Version)
+		require.Equal(t, false, resp.ExecutionOptimistic)
+		require.Equal(t, false, resp.Finalized)
+
+		// Verify the data
+		require.Equal(t, lookaheadSize, len(resp.Data))
+		for i := 0; i < lookaheadSize; i++ {
+			expectedIdx := strconv.FormatUint(uint64(i%numValidators), 10)
+			require.Equal(t, expectedIdx, resp.Data[i])
+		}
+	})
+
+	t.Run("ssz response", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.Header.Set("Accept", "application/octet-stream")
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+		require.Equal(t, "fulu", rec.Header().Get(api.VersionHeader))
+		responseBytes := rec.Body.Bytes()
+		validatorIndexSize := (*primitives.ValidatorIndex)(nil).SizeSSZ()
+		require.Equal(t, len(responseBytes), validatorIndexSize*lookaheadSize)
+
+		recoveredIndices := make([]primitives.ValidatorIndex, lookaheadSize)
+		for i := 0; i < lookaheadSize; i++ {
+			start := i * validatorIndexSize
+			end := start + validatorIndexSize
+
+			idx := ssz.UnmarshallUint64(responseBytes[start:end])
+			recoveredIndices[i] = primitives.ValidatorIndex(idx)
+		}
+		require.DeepEqual(t, lookahead, recoveredIndices)
+	})
+
+	t.Run("pre fulu state", func(t *testing.T) {
+		preEplusSt, _ := util.DeterministicGenesisStateElectra(t, 1)
+		preFuluServer := &Server{
+			Stater: &testutil.MockStater{
+				BeaconState: preEplusSt,
+			},
+			OptimisticModeFetcher: chainService,
+			FinalizationFetcher:   chainService,
+		}
+
+		// Test JSON request
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		preFuluServer.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusBadRequest, rec.Code)
+
+		var errResp struct {
+			Code    int    `json:"code"`
+			Message string `json:"message"`
+		}
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &errResp))
+		require.Equal(t, "state_id is prior to fulu", errResp.Message)
+
+		// Test SSZ request
+		sszReq := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		sszReq.Header.Set("Accept", "application/octet-stream")
+		sszReq.SetPathValue("state_id", "head")
+		sszRec := httptest.NewRecorder()
+		sszRec.Body = new(bytes.Buffer)
+
+		preFuluServer.GetProposerLookahead(sszRec, sszReq)
+		require.Equal(t, http.StatusBadRequest, sszRec.Code)
+
+		var sszErrResp struct {
+			Code    int    `json:"code"`
+			Message string `json:"message"`
+		}
+		require.NoError(t, json.Unmarshal(sszRec.Body.Bytes(), &sszErrResp))
+		require.Equal(t, "state_id is prior to fulu", sszErrResp.Message)
+	})
+
+	t.Run("missing state_id parameter", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusBadRequest, rec.Code)
+
+		var errResp struct {
+			Code    int    `json:"code"`
+			Message string `json:"message"`
+		}
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &errResp))
+		require.Equal(t, "state_id is required in URL params", errResp.Message)
+	})
+
+	t.Run("optimistic node", func(t *testing.T) {
+		optimisticChainService := &chainMock.ChainService{
+			Optimistic:     true,
+			FinalizedRoots: map[[32]byte]bool{},
+		}
+		optimisticServer := &Server{
+			Stater:                server.Stater,
+			OptimisticModeFetcher: optimisticChainService,
+			FinalizationFetcher:   optimisticChainService,
+		}
+
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		optimisticServer.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+
+		var resp structs.GetProposerLookaheadResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+		require.Equal(t, true, resp.ExecutionOptimistic)
+	})
+
+	t.Run("finalized node", func(t *testing.T) {
+		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
+		require.NoError(t, err)
+
+		finalizedChainService := &chainMock.ChainService{
+			Optimistic:     false,
+			FinalizedRoots: map[[32]byte]bool{blockRoot: true},
+		}
+		finalizedServer := &Server{
+			Stater:                server.Stater,
+			OptimisticModeFetcher: finalizedChainService,
+			FinalizationFetcher:   finalizedChainService,
+		}
+
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		finalizedServer.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+
+		var resp structs.GetProposerLookaheadResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+		require.Equal(t, true, resp.Finalized)
+	})
+}

changelog/james-prysm_proposer-lookahead-api.md

@@ -0,0 +1,3 @@
+### Added
+
+- Implements the `/eth/v1/beacon/states/{state_id}/proposer_lookahead` beacon api endpoint.

testing/util/BUILD.bazel

@@ -22,6 +22,7 @@ go_library(
         "electra_state.go",
         "fulu.go",
         "fulu_block.go",
+        "fulu_state.go",
         "helpers.go",
         "lightclient.go",
         "logging.go",

testing/util/fulu_state.go

@@ -0,0 +1,308 @@
+package util
+
+import (
+	"context"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stateutil"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/crypto/bls"
+	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/pkg/errors"
+)
+
+// DeterministicGenesisStateFulu returns a genesis state in Fulu format made using the deterministic deposits.
+func DeterministicGenesisStateFulu(t testing.TB, numValidators uint64) (state.BeaconState, []bls.SecretKey) {
+	deposits, privKeys, err := DeterministicDepositsAndKeys(numValidators)
+	if err != nil {
+		t.Fatal(errors.Wrapf(err, "failed to get %d deposits", numValidators))
+	}
+	eth1Data, err := DeterministicEth1Data(len(deposits))
+	if err != nil {
+		t.Fatal(errors.Wrapf(err, "failed to get eth1data for %d deposits", numValidators))
+	}
+	beaconState, err := genesisBeaconStateFulu(t.Context(), deposits, uint64(0), eth1Data)
+	if err != nil {
+		t.Fatal(errors.Wrapf(err, "failed to get genesis beacon state of %d validators", numValidators))
+	}
+	if err := setKeysToActiveFulu(beaconState); err != nil {
+		t.Fatal(errors.Wrapf(err, "failed to set keys to active"))
+	}
+	resetCache()
+	return beaconState, privKeys
+}
+
+// setKeysToActiveFulu is a function to set the validators to active post fulu, fulu no longer processes deposits based on eth1data
+func setKeysToActiveFulu(beaconState state.BeaconState) error {
+	vals := make([]*ethpb.Validator, len(beaconState.Validators()))
+	for i, val := range beaconState.Validators() {
+		val.ActivationEpoch = 0
+		val.EffectiveBalance = params.BeaconConfig().MinActivationBalance
+		vals[i] = val
+	}
+	return beaconState.SetValidators(vals)
+}
+
+// genesisBeaconStateFulu returns the genesis beacon state.
+func genesisBeaconStateFulu(ctx context.Context, deposits []*ethpb.Deposit, genesisTime uint64, eth1Data *ethpb.Eth1Data) (state.BeaconState, error) {
+	st, err := emptyGenesisStateFulu()
+	if err != nil {
+		return nil, err
+	}
+
+	// Process initial deposits.
+	st, err = helpers.UpdateGenesisEth1Data(st, deposits, eth1Data)
+	if err != nil {
+		return nil, err
+	}
+
+	st, err = processPreGenesisDeposits(ctx, st, deposits)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not process validator deposits")
+	}
+
+	return buildGenesisBeaconStateFulu(genesisTime, st, st.Eth1Data())
+}
+
+// emptyGenesisStateFulu returns an empty genesis state in Fulu format.
+func emptyGenesisStateFulu() (state.BeaconState, error) {
+	st := &ethpb.BeaconStateFulu{
+		// Misc fields.
+		Slot: 0,
+		Fork: &ethpb.Fork{
+			PreviousVersion: params.BeaconConfig().ElectraForkVersion,
+			CurrentVersion:  params.BeaconConfig().FuluForkVersion,
+			Epoch:           0,
+		},
+		// Validator registry fields.
+		Validators:       []*ethpb.Validator{},
+		Balances:         []uint64{},
+		InactivityScores: []uint64{},
+
+		JustificationBits:          []byte{0},
+		HistoricalRoots:            [][]byte{},
+		CurrentEpochParticipation:  []byte{},
+		PreviousEpochParticipation: []byte{},
+
+		// Eth1 data.
+		Eth1Data:         &ethpb.Eth1Data{},
+		Eth1DataVotes:    []*ethpb.Eth1Data{},
+		Eth1DepositIndex: 0,
+
+		LatestExecutionPayloadHeader: &enginev1.ExecutionPayloadHeaderDeneb{},
+
+		// Electra fields
+		DepositBalanceToConsume:       primitives.Gwei(0),
+		ExitBalanceToConsume:          primitives.Gwei(0),
+		ConsolidationBalanceToConsume: primitives.Gwei(0),
+
+		// Fulu specific field
+		ProposerLookahead: []uint64{},
+	}
+	return state_native.InitializeFromProtoFulu(st)
+}
+
+func buildGenesisBeaconStateFulu(genesisTime uint64, preState state.BeaconState, eth1Data *ethpb.Eth1Data) (state.BeaconState, error) {
+	if eth1Data == nil {
+		return nil, errors.New("no eth1data provided for genesis state")
+	}
+
+	randaoMixes := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
+	for i := 0; i < len(randaoMixes); i++ {
+		h := make([]byte, 32)
+		copy(h, eth1Data.BlockHash)
+		randaoMixes[i] = h
+	}
+
+	zeroHash := params.BeaconConfig().ZeroHash[:]
+
+	activeIndexRoots := make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector)
+	for i := 0; i < len(activeIndexRoots); i++ {
+		activeIndexRoots[i] = zeroHash
+	}
+
+	blockRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
+	for i := 0; i < len(blockRoots); i++ {
+		blockRoots[i] = zeroHash
+	}
+
+	stateRoots := make([][]byte, params.BeaconConfig().SlotsPerHistoricalRoot)
+	for i := 0; i < len(stateRoots); i++ {
+		stateRoots[i] = zeroHash
+	}
+
+	slashings := make([]uint64, params.BeaconConfig().EpochsPerSlashingsVector)
+
+	genesisValidatorsRoot, err := stateutil.ValidatorRegistryRoot(preState.Validators())
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not hash tree root genesis validators %v", err)
+	}
+
+	prevEpochParticipation, err := preState.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currEpochParticipation, err := preState.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	scores, err := preState.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	tab, err := helpers.TotalActiveBalance(preState)
+	if err != nil {
+		return nil, err
+	}
+
+	st := &ethpb.BeaconStateFulu{
+		// Misc fields.
+		Slot:                  0,
+		GenesisTime:           genesisTime,
+		GenesisValidatorsRoot: genesisValidatorsRoot[:],
+
+		Fork: &ethpb.Fork{
+			PreviousVersion: params.BeaconConfig().GenesisForkVersion,
+			CurrentVersion:  params.BeaconConfig().GenesisForkVersion,
+			Epoch:           0,
+		},
+
+		// Validator registry fields.
+		Validators:                 preState.Validators(),
+		Balances:                   preState.Balances(),
+		PreviousEpochParticipation: prevEpochParticipation,
+		CurrentEpochParticipation:  currEpochParticipation,
+		InactivityScores:           scores,
+
+		// Randomness and committees.
+		RandaoMixes: randaoMixes,
+
+		// Finality.
+		PreviousJustifiedCheckpoint: &ethpb.Checkpoint{
+			Epoch: 0,
+			Root:  params.BeaconConfig().ZeroHash[:],
+		},
+		CurrentJustifiedCheckpoint: &ethpb.Checkpoint{
+			Epoch: 0,
+			Root:  params.BeaconConfig().ZeroHash[:],
+		},
+		JustificationBits: []byte{0},
+		FinalizedCheckpoint: &ethpb.Checkpoint{
+			Epoch: 0,
+			Root:  params.BeaconConfig().ZeroHash[:],
+		},
+
+		HistoricalRoots: [][]byte{},
+		BlockRoots:      blockRoots,
+		StateRoots:      stateRoots,
+		Slashings:       slashings,
+
+		// Eth1 data.
+		Eth1Data:         eth1Data,
+		Eth1DataVotes:    []*ethpb.Eth1Data{},
+		Eth1DepositIndex: preState.Eth1DepositIndex(),
+
+		// Electra Data
+		DepositRequestsStartIndex:     params.BeaconConfig().UnsetDepositRequestsStartIndex,
+		ExitBalanceToConsume:          helpers.ActivationExitChurnLimit(primitives.Gwei(tab)),
+		EarliestConsolidationEpoch:    helpers.ActivationExitEpoch(slots.ToEpoch(preState.Slot())),
+		ConsolidationBalanceToConsume: helpers.ConsolidationChurnLimit(primitives.Gwei(tab)),
+		PendingDeposits:               make([]*ethpb.PendingDeposit, 0),
+		PendingPartialWithdrawals:     make([]*ethpb.PendingPartialWithdrawal, 0),
+		PendingConsolidations:         make([]*ethpb.PendingConsolidation, 0),
+	}
+
+	var scBits [fieldparams.SyncAggregateSyncCommitteeBytesLength]byte
+	bodyRoot, err := (&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:      scBits[:],
+			SyncCommitteeSignature: make([]byte, 96),
+		},
+		ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
+			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),
+		},
+		ExecutionRequests: &enginev1.ExecutionRequests{
+			Deposits:       make([]*enginev1.DepositRequest, 0),
+			Withdrawals:    make([]*enginev1.WithdrawalRequest, 0),
+			Consolidations: make([]*enginev1.ConsolidationRequest, 0),
+		},
+	}).HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not hash tree root empty block body")
+	}
+
+	st.LatestBlockHeader = &ethpb.BeaconBlockHeader{
+		ParentRoot: zeroHash,
+		StateRoot:  zeroHash,
+		BodyRoot:   bodyRoot[:],
+	}
+
+	var pubKeys [][]byte
+	vals := preState.Validators()
+	for i := uint64(0); i < params.BeaconConfig().SyncCommitteeSize; i++ {
+		j := i % uint64(len(vals))
+		pubKeys = append(pubKeys, vals[j].PublicKey)
+	}
+	aggregated, err := bls.AggregatePublicKeys(pubKeys)
+	if err != nil {
+		return nil, err
+	}
+	st.CurrentSyncCommittee = &ethpb.SyncCommittee{
+		Pubkeys:         pubKeys,
+		AggregatePubkey: aggregated.Marshal(),
+	}
+	st.NextSyncCommittee = &ethpb.SyncCommittee{
+		Pubkeys:         pubKeys,
+		AggregatePubkey: aggregated.Marshal(),
+	}
+
+	st.LatestExecutionPayloadHeader = &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),
+		ExtraData:        make([]byte, 0),
+		BaseFeePerGas:    make([]byte, 32),
+		BlockHash:        make([]byte, 32),
+		TransactionsRoot: make([]byte, 32),
+		WithdrawalsRoot:  make([]byte, 32),
+	}
+
+	// Calculate proposer lookahead for genesis
+	preFuluSt, err := state_native.InitializeFromProtoFulu(st)
+	if err != nil {
+		return nil, err
+	}
+	proposerLookahead, err := helpers.InitializeProposerLookahead(context.Background(), preFuluSt, slots.ToEpoch(preState.Slot()))
+	if err != nil {
+		return nil, errors.Wrap(err, "could not calculate proposer lookahead")
+	}
+
+	// Fulu specific field
+	st.ProposerLookahead = proposerLookahead
+	return state_native.InitializeFromProtoFulu(st)
+}