Fix join to avoid recursive call

* Add additional spans for tracing GetDuties

* Changelog fragment

WORKSPACE

@@ -255,7 +255,7 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.5.0-beta.5"
+consensus_spec_version = "v1.5.0"
 
 bls_test_version = "v0.1.1"
 
@@ -271,7 +271,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-H+Pt4z+HCVDnEBAv814yvsjR7f5l1IpumjFoTj2XnLE=",
+    integrity = "sha256-JljxS/if/t0qvGWcf5CgsX+72fj90yGTg/uEgC56y7U=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )
 
@@ -287,7 +287,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-Dqiwf5BG7yYyURGf+i87AIdArAyztvcgjoi2kSxrGvo=",
+    integrity = "sha256-NRba2h4zqb2LAXyDPglHTtkT4gVyuwpY708XmwXKXV8=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )
 
@@ -303,7 +303,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-xrmsFF243pzXHAjh1EQYKS9gtcwmtHK3wRZDSLlVVRk=",
+    integrity = "sha256-hpbtKUbc3NHtVcUPk/Zm+Hn57G2ijI9qvXJwl9hc/tM=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )
 
@@ -318,7 +318,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-c+gGapqifCvFtmtxfhOwieBDO2Syxp13GECWEpWM/Ho=",
+    integrity = "sha256-Wy3YcJxoXiKQwrGgJecrtjtdokc4X/VUNBmyQXJf0Oc=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )

api/server/structs/BUILD.bazel

@@ -57,6 +57,7 @@ go_test(
     deps = [
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",

api/server/structs/conversions_state.go

@@ -26,10 +26,7 @@ func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error)
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -116,10 +113,7 @@ func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAlt
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -225,10 +219,7 @@ func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconState
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -347,10 +338,7 @@ func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCa
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -488,10 +476,7 @@ func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDene
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -629,10 +614,7 @@ func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateEl
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -815,10 +797,7 @@ func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu,
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)

api/server/structs/conversions_test.go

@@ -4,7 +4,9 @@ import (
 	"testing"
 
 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
 func TestDepositSnapshotFromConsensus(t *testing.T) {
@@ -102,12 +104,266 @@ func TestProposerSlashing_ToConsensus(t *testing.T) {
 	require.ErrorContains(t, errNilValue.Error(), err)
 }
 
+func TestProposerSlashing_FromConsensus(t *testing.T) {
+	input := []*eth.ProposerSlashing{
+		{
+			Header_1: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          1,
+					ProposerIndex: 2,
+					ParentRoot:    []byte{3},
+					StateRoot:     []byte{4},
+					BodyRoot:      []byte{5},
+				},
+				Signature: []byte{6},
+			},
+			Header_2: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          7,
+					ProposerIndex: 8,
+					ParentRoot:    []byte{9},
+					StateRoot:     []byte{10},
+					BodyRoot:      []byte{11},
+				},
+				Signature: []byte{12},
+			},
+		},
+		{
+			Header_1: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          13,
+					ProposerIndex: 14,
+					ParentRoot:    []byte{15},
+					StateRoot:     []byte{16},
+					BodyRoot:      []byte{17},
+				},
+				Signature: []byte{18},
+			},
+			Header_2: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          19,
+					ProposerIndex: 20,
+					ParentRoot:    []byte{21},
+					StateRoot:     []byte{22},
+					BodyRoot:      []byte{23},
+				},
+				Signature: []byte{24},
+			},
+		},
+	}
+
+	expectedResult := []*ProposerSlashing{
+		{
+			SignedHeader1: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "1",
+					ProposerIndex: "2",
+					ParentRoot:    hexutil.Encode([]byte{3}),
+					StateRoot:     hexutil.Encode([]byte{4}),
+					BodyRoot:      hexutil.Encode([]byte{5}),
+				},
+				Signature: hexutil.Encode([]byte{6}),
+			},
+			SignedHeader2: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "7",
+					ProposerIndex: "8",
+					ParentRoot:    hexutil.Encode([]byte{9}),
+					StateRoot:     hexutil.Encode([]byte{10}),
+					BodyRoot:      hexutil.Encode([]byte{11}),
+				},
+				Signature: hexutil.Encode([]byte{12}),
+			},
+		},
+		{
+			SignedHeader1: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "13",
+					ProposerIndex: "14",
+					ParentRoot:    hexutil.Encode([]byte{15}),
+					StateRoot:     hexutil.Encode([]byte{16}),
+					BodyRoot:      hexutil.Encode([]byte{17}),
+				},
+				Signature: hexutil.Encode([]byte{18}),
+			},
+			SignedHeader2: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "19",
+					ProposerIndex: "20",
+					ParentRoot:    hexutil.Encode([]byte{21}),
+					StateRoot:     hexutil.Encode([]byte{22}),
+					BodyRoot:      hexutil.Encode([]byte{23}),
+				},
+				Signature: hexutil.Encode([]byte{24}),
+			},
+		},
+	}
+
+	result := ProposerSlashingsFromConsensus(input)
+	assert.DeepEqual(t, expectedResult, result)
+}
+
 func TestAttesterSlashing_ToConsensus(t *testing.T) {
 	a := &AttesterSlashing{Attestation1: nil, Attestation2: nil}
 	_, err := a.ToConsensus()
 	require.ErrorContains(t, errNilValue.Error(), err)
 }
 
+func TestAttesterSlashing_FromConsensus(t *testing.T) {
+	input := []*eth.AttesterSlashing{
+		{
+			Attestation_1: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{1, 2},
+				Data: &eth.AttestationData{
+					Slot:            3,
+					CommitteeIndex:  4,
+					BeaconBlockRoot: []byte{5},
+					Source: &eth.Checkpoint{
+						Epoch: 6,
+						Root:  []byte{7},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 8,
+						Root:  []byte{9},
+					},
+				},
+				Signature: []byte{10},
+			},
+			Attestation_2: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{11, 12},
+				Data: &eth.AttestationData{
+					Slot:            13,
+					CommitteeIndex:  14,
+					BeaconBlockRoot: []byte{15},
+					Source: &eth.Checkpoint{
+						Epoch: 16,
+						Root:  []byte{17},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 18,
+						Root:  []byte{19},
+					},
+				},
+				Signature: []byte{20},
+			},
+		},
+		{
+			Attestation_1: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{21, 22},
+				Data: &eth.AttestationData{
+					Slot:            23,
+					CommitteeIndex:  24,
+					BeaconBlockRoot: []byte{25},
+					Source: &eth.Checkpoint{
+						Epoch: 26,
+						Root:  []byte{27},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 28,
+						Root:  []byte{29},
+					},
+				},
+				Signature: []byte{30},
+			},
+			Attestation_2: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{31, 32},
+				Data: &eth.AttestationData{
+					Slot:            33,
+					CommitteeIndex:  34,
+					BeaconBlockRoot: []byte{35},
+					Source: &eth.Checkpoint{
+						Epoch: 36,
+						Root:  []byte{37},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 38,
+						Root:  []byte{39},
+					},
+				},
+				Signature: []byte{40},
+			},
+		},
+	}
+
+	expectedResult := []*AttesterSlashing{
+		{
+			Attestation1: &IndexedAttestation{
+				AttestingIndices: []string{"1", "2"},
+				Data: &AttestationData{
+					Slot:            "3",
+					CommitteeIndex:  "4",
+					BeaconBlockRoot: hexutil.Encode([]byte{5}),
+					Source: &Checkpoint{
+						Epoch: "6",
+						Root:  hexutil.Encode([]byte{7}),
+					},
+					Target: &Checkpoint{
+						Epoch: "8",
+						Root:  hexutil.Encode([]byte{9}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{10}),
+			},
+			Attestation2: &IndexedAttestation{
+				AttestingIndices: []string{"11", "12"},
+				Data: &AttestationData{
+					Slot:            "13",
+					CommitteeIndex:  "14",
+					BeaconBlockRoot: hexutil.Encode([]byte{15}),
+					Source: &Checkpoint{
+						Epoch: "16",
+						Root:  hexutil.Encode([]byte{17}),
+					},
+					Target: &Checkpoint{
+						Epoch: "18",
+						Root:  hexutil.Encode([]byte{19}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{20}),
+			},
+		},
+		{
+			Attestation1: &IndexedAttestation{
+				AttestingIndices: []string{"21", "22"},
+				Data: &AttestationData{
+					Slot:            "23",
+					CommitteeIndex:  "24",
+					BeaconBlockRoot: hexutil.Encode([]byte{25}),
+					Source: &Checkpoint{
+						Epoch: "26",
+						Root:  hexutil.Encode([]byte{27}),
+					},
+					Target: &Checkpoint{
+						Epoch: "28",
+						Root:  hexutil.Encode([]byte{29}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{30}),
+			},
+			Attestation2: &IndexedAttestation{
+				AttestingIndices: []string{"31", "32"},
+				Data: &AttestationData{
+					Slot:            "33",
+					CommitteeIndex:  "34",
+					BeaconBlockRoot: hexutil.Encode([]byte{35}),
+					Source: &Checkpoint{
+						Epoch: "36",
+						Root:  hexutil.Encode([]byte{37}),
+					},
+					Target: &Checkpoint{
+						Epoch: "38",
+						Root:  hexutil.Encode([]byte{39}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{40}),
+			},
+		},
+	}
+
+	result := AttesterSlashingsFromConsensus(input)
+	assert.DeepEqual(t, expectedResult, result)
+}
+
 func TestIndexedAttestation_ToConsensus(t *testing.T) {
 	a := &IndexedAttestation{
 		AttestingIndices: []string{"1"},

api/server/structs/endpoints_beacon.go

@@ -263,6 +263,13 @@ type ChainHead struct {
 	OptimisticStatus           bool   `json:"optimistic_status"`
 }
 
+type GetPendingConsolidationsResponse struct {
+	Version             string                  `json:"version"`
+	ExecutionOptimistic bool                    `json:"execution_optimistic"`
+	Finalized           bool                    `json:"finalized"`
+	Data                []*PendingConsolidation `json:"data"`
+}
+
 type GetPendingDepositsResponse struct {
 	Version             string            `json:"version"`
 	ExecutionOptimistic bool              `json:"execution_optimistic"`

api/server/structs/other.go

@@ -253,7 +253,7 @@ type PendingDeposit struct {
 }
 
 type PendingPartialWithdrawal struct {
-	Index             string `json:"index"`
+	Index             string `json:"validator_index"`
 	Amount            string `json:"amount"`
 	WithdrawableEpoch string `json:"withdrawable_epoch"`
 }

beacon-chain/blockchain/BUILD.bazel

@@ -163,6 +163,7 @@ go_test(
         "//beacon-chain/operations/slashings:go_default_library",
         "//beacon-chain/operations/voluntaryexits:go_default_library",
         "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/startup:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",

beacon-chain/blockchain/execution_engine.go

@@ -184,13 +184,17 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 	return payloadID, nil
 }
 
-func firePayloadAttributesEvent(_ context.Context, f event.SubscriberSender, nextSlot primitives.Slot) {
+func (s *Service) firePayloadAttributesEvent(f event.SubscriberSender, block interfaces.ReadOnlySignedBeaconBlock, root [32]byte, nextSlot primitives.Slot) {
+	// If we're syncing a block in the past and init-sync is still running, we shouldn't fire this event.
+	if !s.cfg.SyncChecker.Synced() {
+		return
+	}
 	// the fcu args have differing amounts of completeness based on the code path,
 	// and there is work we only want to do if a client is actually listening to the events beacon api endpoint.
 	// temporary solution: just fire a blank event and fill in the details in the api handler.
 	f.Send(&feed.Event{
 		Type: statefeed.PayloadAttributes,
-		Data: payloadattribute.EventData{ProposalSlot: nextSlot},
+		Data: payloadattribute.EventData{HeadBlock: block, HeadRoot: root, ProposalSlot: nextSlot},
 	})
 }
 

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -102,7 +102,7 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 		log.WithError(err).Error("could not save head")
 	}
 
-	go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
+	go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), args.headBlock, args.headRoot, s.CurrentSlot()+1)
 
 	// Only need to prune attestations from pool if the head has changed.
 	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)

beacon-chain/blockchain/kzg/BUILD.bazel

@@ -30,7 +30,8 @@ go_test(
     deps = [
         "//consensus-types/blocks:go_default_library",
         "//testing/require:go_default_library",
-        "//testing/util:go_default_library",
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )

beacon-chain/blockchain/kzg/validation_test.go

@@ -1,12 +1,16 @@
 package kzg
 
 import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/sirupsen/logrus"
 )
 
 func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZGProof, error) {
@@ -37,7 +41,7 @@ func TestBytesToAny(t *testing.T) {
 }
 
 func TestGenerateCommitmentAndProof(t *testing.T) {
-	blob := util.GetRandBlob(123)
+	blob := getRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
 	expectedCommitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}
@@ -45,3 +49,36 @@ func TestGenerateCommitmentAndProof(t *testing.T) {
 	require.Equal(t, expectedCommitment, commitment)
 	require.Equal(t, expectedProof, proof)
 }
+
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func getRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// Returns a random blob using the passed seed as entropy
+func getRandBlob(seed int64) GoKZG.Blob {
+	var blob GoKZG.Blob
+	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
+		fieldElementBytes := getRandFieldElement(seed + int64(i))
+		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
+	}
+	return blob
+}

beacon-chain/blockchain/mock_test.go

@@ -20,6 +20,7 @@ func testServiceOptsWithDB(t *testing.T) []Option {
 		WithForkChoiceStore(fcs),
 		WithClockSynchronizer(cs),
 		WithStateNotifier(&mock.MockStateNotifier{RecordEvents: true}),
+		WithSyncChecker(&mock.MockSyncChecker{}),
 	}
 }
 

beacon-chain/blockchain/process_block.go

@@ -729,9 +729,13 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
 	// return early if we are not proposing next slot
 	if attribute.IsEmpty() {
+		headBlock, err := s.headBlock()
+		if err != nil {
+			log.WithError(err).WithField("head_root", headRoot).Error("unable to retrieve head block to fire payload attributes event")
+		}
 		// notifyForkchoiceUpdate fires the payload attribute event. But in this case, we won't
 		// call notifyForkchoiceUpdate, so the event is fired here.
-		go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), headBlock, headRoot, s.CurrentSlot()+1)
 		return
 	}
 

beacon-chain/blockchain/process_block_helpers.go

@@ -103,15 +103,29 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 		log.WithError(err).Debug("Could not check if block is optimistic")
 		optimistic = true
 	}
+	currEpoch := slots.ToEpoch(s.CurrentSlot())
+	currDependenRoot, err := s.cfg.ForkChoiceStore.DependentRoot(currEpoch)
+	if err != nil {
+		log.WithError(err).Debug("Could not get dependent root")
+	}
+	prevDependentRoot := [32]byte{}
+	if currEpoch > 0 {
+		prevDependentRoot, err = s.cfg.ForkChoiceStore.DependentRoot(currEpoch - 1)
+		if err != nil {
+			log.WithError(err).Debug("Could not get previous dependent root")
+		}
+	}
 	// Send notification of the processed block to the state feed.
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.BlockProcessed,
 		Data: &statefeed.BlockProcessedData{
-			Slot:        cfg.roblock.Block().Slot(),
-			BlockRoot:   cfg.roblock.Root(),
-			SignedBlock: cfg.roblock,
-			Verified:    true,
-			Optimistic:  optimistic,
+			Slot:              cfg.roblock.Block().Slot(),
+			BlockRoot:         cfg.roblock.Root(),
+			SignedBlock:       cfg.roblock,
+			CurrDependentRoot: currDependenRoot,
+			PrevDependentRoot: prevDependentRoot,
+			Verified:          true,
+			Optimistic:        optimistic,
 		},
 	})
 }
@@ -295,6 +309,11 @@ func (s *Service) processLightClientFinalityUpdate(
 		Type: statefeed.LightClientFinalityUpdate,
 		Data: newUpdate,
 	})
+
+	if err = s.cfg.P2p.BroadcastLightClientFinalityUpdate(ctx, newUpdate); err != nil {
+		return errors.Wrap(err, "could not broadcast light client finality update")
+	}
+
 	return nil
 }
 
@@ -344,6 +363,10 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		Data: newUpdate,
 	})
 
+	if err = s.cfg.P2p.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
+		return errors.Wrap(err, "could not broadcast light client optimistic update")
+	}
+
 	return nil
 }
 

beacon-chain/blockchain/process_block_test.go

@@ -24,6 +24,7 @@ import (
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations/kv"
+	mockp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -3309,6 +3310,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 	params.OverrideBeaconConfig(beaconCfg)
 
 	s, tr := minimalTestService(t)
+	s.cfg.P2p = &mockp2p.FakeP2P{}
 	ctx := tr.ctx
 
 	testCases := []struct {
@@ -3444,6 +3446,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 	params.OverrideBeaconConfig(beaconCfg)
 
 	s, tr := minimalTestService(t)
+	s.cfg.P2p = &mockp2p.FakeP2P{}
 	ctx := tr.ctx
 
 	testCases := []struct {

beacon-chain/blockchain/setup_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"google.golang.org/protobuf/proto"
@@ -66,6 +67,16 @@ func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.B
 	return nil
 }
 
+func (mb *mockBroadcaster) BroadcastLightClientOptimisticUpdate(_ context.Context, _ interfaces.LightClientOptimisticUpdate) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
+func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfaces.LightClientFinalityUpdate) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }
 

beacon-chain/blockchain/testing/mock.go

@@ -719,3 +719,14 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil
 }
+
+// MockSyncChecker is a mock implementation of blockchain.Checker.
+// We can't make an assertion here that this is true because that would create a circular dependency.
+type MockSyncChecker struct {
+	synced bool
+}
+
+// Synced satisfies the blockchain.Checker interface.
+func (m *MockSyncChecker) Synced() bool {
+	return m.synced
+}

beacon-chain/core/altair/upgrade.go

@@ -67,10 +67,6 @@ func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.Beacon
 	epoch := time.CurrentEpoch(state)
 
 	numValidators := state.NumValidators()
-	hrs, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	s := &ethpb.BeaconStateAltair{
 		GenesisTime:           state.GenesisTime(),
 		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
@@ -83,7 +79,7 @@ func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.Beacon
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             hrs,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/altair/upgrade_test.go

@@ -82,10 +82,8 @@ func TestUpgradeToAltair(t *testing.T) {
 	require.DeepSSZEqual(t, preForkState.LatestBlockHeader(), aState.LatestBlockHeader())
 	require.DeepSSZEqual(t, preForkState.BlockRoots(), aState.BlockRoots())
 	require.DeepSSZEqual(t, preForkState.StateRoots(), aState.StateRoots())
-	r1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	r2, err := aState.HistoricalRoots()
-	require.NoError(t, err)
+	r1 := preForkState.HistoricalRoots()
+	r2 := aState.HistoricalRoots()
 	require.DeepSSZEqual(t, r1, r2)
 	require.DeepSSZEqual(t, preForkState.Eth1Data(), aState.Eth1Data())
 	require.DeepSSZEqual(t, preForkState.Eth1DataVotes(), aState.Eth1DataVotes())

beacon-chain/core/capella/upgrade.go

@@ -42,10 +42,6 @@ func UpgradeToCapella(state state.BeaconState) (state.BeaconState, error) {
 		return nil, err
 	}
 
-	hrs, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	s := &ethpb.BeaconStateCapella{
 		GenesisTime:           state.GenesisTime(),
 		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
@@ -58,7 +54,7 @@ func UpgradeToCapella(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             hrs,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/deneb/upgrade.go

@@ -57,10 +57,6 @@ func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
 	if err != nil {
 		return nil, err
 	}
-	historicalRoots, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 
 	s := &ethpb.BeaconStateDeneb{
 		GenesisTime:           state.GenesisTime(),
@@ -74,7 +70,7 @@ func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             historicalRoots,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/deneb/upgrade_test.go

@@ -47,10 +47,8 @@ func TestUpgradeToDeneb(t *testing.T) {
 	require.NoError(t, err)
 	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
 
-	hr1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	hr2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	hr1 := preForkState.HistoricalRoots()
+	hr2 := mSt.HistoricalRoots()
 	require.DeepEqual(t, hr1, hr2)
 
 	f := mSt.Fork()

beacon-chain/core/electra/upgrade.go

@@ -170,10 +170,6 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 	if err != nil {
 		return nil, err
 	}
-	historicalRoots, err := beaconState.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	excessBlobGas, err := payloadHeader.ExcessBlobGas()
 	if err != nil {
 		return nil, err
@@ -223,7 +219,7 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 		LatestBlockHeader:           beaconState.LatestBlockHeader(),
 		BlockRoots:                  beaconState.BlockRoots(),
 		StateRoots:                  beaconState.StateRoots(),
-		HistoricalRoots:             historicalRoots,
+		HistoricalRoots:             beaconState.HistoricalRoots(),
 		Eth1Data:                    beaconState.Eth1Data(),
 		Eth1DataVotes:               beaconState.Eth1DataVotes(),
 		Eth1DepositIndex:            beaconState.Eth1DepositIndex(),

beacon-chain/core/electra/upgrade_test.go

@@ -77,10 +77,8 @@ func TestUpgradeToElectra(t *testing.T) {
 	require.NoError(t, err)
 	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
 
-	hr1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	hr2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	hr1 := preForkState.HistoricalRoots()
+	hr2 := mSt.HistoricalRoots()
 	require.DeepEqual(t, hr1, hr2)
 
 	f := mSt.Fork()

beacon-chain/core/epoch/epoch_processing_test.go

@@ -148,8 +148,7 @@ func TestProcessFinalUpdates_CanProcess(t *testing.T) {
 	assert.DeepNotEqual(t, params.BeaconConfig().ZeroHash[:], mix, "latest RANDAO still zero hashes")
 
 	// Verify historical root accumulator was appended.
-	roots, err := newS.HistoricalRoots()
-	require.NoError(t, err)
+	roots := newS.HistoricalRoots()
 	assert.Equal(t, 1, len(roots), "Unexpected slashed balance")
 	currAtt, err := newS.CurrentEpochAttestations()
 	require.NoError(t, err)
@@ -379,8 +378,7 @@ func TestProcessHistoricalDataUpdate(t *testing.T) {
 				return st
 			},
 			verifier: func(st state.BeaconState) {
-				roots, err := st.HistoricalRoots()
-				require.NoError(t, err)
+				roots := st.HistoricalRoots()
 				require.Equal(t, 0, len(roots))
 			},
 		},
@@ -393,8 +391,7 @@ func TestProcessHistoricalDataUpdate(t *testing.T) {
 				return st
 			},
 			verifier: func(st state.BeaconState) {
-				roots, err := st.HistoricalRoots()
-				require.NoError(t, err)
+				roots := st.HistoricalRoots()
 				require.Equal(t, 1, len(roots))
 
 				b := &ethpb.HistoricalBatch{
@@ -431,8 +428,7 @@ func TestProcessHistoricalDataUpdate(t *testing.T) {
 					StateSummaryRoot: sr[:],
 				}
 				require.DeepEqual(t, b, summaries[0])
-				hrs, err := st.HistoricalRoots()
-				require.NoError(t, err)
+				hrs := st.HistoricalRoots()
 				require.DeepEqual(t, hrs, [][]byte{})
 			},
 		},

beacon-chain/core/execution/upgrade.go

@@ -35,10 +35,6 @@ func UpgradeToBellatrix(state state.BeaconState) (state.BeaconState, error) {
 		return nil, err
 	}
 
-	hrs, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	s := &ethpb.BeaconStateBellatrix{
 		GenesisTime:           state.GenesisTime(),
 		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
@@ -51,7 +47,7 @@ func UpgradeToBellatrix(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             hrs,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/execution/upgrade_test.go

@@ -24,10 +24,8 @@ func TestUpgradeToBellatrix(t *testing.T) {
 	require.DeepSSZEqual(t, preForkState.LatestBlockHeader(), mSt.LatestBlockHeader())
 	require.DeepSSZEqual(t, preForkState.BlockRoots(), mSt.BlockRoots())
 	require.DeepSSZEqual(t, preForkState.StateRoots(), mSt.StateRoots())
-	r1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	r2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	r1 := preForkState.HistoricalRoots()
+	r2 := mSt.HistoricalRoots()
 	require.DeepSSZEqual(t, r1, r2)
 	require.DeepSSZEqual(t, preForkState.Eth1Data(), mSt.Eth1Data())
 	require.DeepSSZEqual(t, preForkState.Eth1DataVotes(), mSt.Eth1DataVotes())

beacon-chain/core/feed/block/events.go

@@ -11,6 +11,8 @@ const (
 
 // ReceivedBlockData is the data sent with ReceivedBlock events.
 type ReceivedBlockData struct {
-	SignedBlock  interfaces.ReadOnlySignedBeaconBlock
-	IsOptimistic bool
+	SignedBlock       interfaces.ReadOnlySignedBeaconBlock
+	CurrDependentRoot [32]byte
+	PrevDependentRoot [32]byte
+	IsOptimistic      bool
 }

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

@@ -43,6 +43,10 @@ type BlockProcessedData struct {
 	BlockRoot [32]byte
 	// SignedBlock is the physical processed block.
 	SignedBlock interfaces.ReadOnlySignedBeaconBlock
+	// CurrDependentRoot is the current dependent root
+	CurrDependentRoot [32]byte
+	// PrevDependentRoot is the previous dependent root
+	PrevDependentRoot [32]byte
 	// Verified is true if the block's BLS contents have been verified.
 	Verified bool
 	// Optimistic is true if the block is optimistic.

beacon-chain/core/fulu/upgrade.go

@@ -57,10 +57,6 @@ func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 	if err != nil {
 		return nil, err
 	}
-	historicalRoots, err := beaconState.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	excessBlobGas, err := payloadHeader.ExcessBlobGas()
 	if err != nil {
 		return nil, err
@@ -118,7 +114,7 @@ func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           beaconState.LatestBlockHeader(),
 		BlockRoots:                  beaconState.BlockRoots(),
 		StateRoots:                  beaconState.StateRoots(),
-		HistoricalRoots:             historicalRoots,
+		HistoricalRoots:             beaconState.HistoricalRoots(),
 		Eth1Data:                    beaconState.Eth1Data(),
 		Eth1DataVotes:               beaconState.Eth1DataVotes(),
 		Eth1DepositIndex:            beaconState.Eth1DepositIndex(),

beacon-chain/core/fulu/upgrade_test.go

@@ -43,10 +43,8 @@ func TestUpgradeToFulu(t *testing.T) {
 	require.DeepSSZEqual(t, preForkState.BlockRoots(), mSt.BlockRoots())
 	require.DeepSSZEqual(t, preForkState.StateRoots(), mSt.StateRoots())
 
-	hr1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	hr2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	hr1 := preForkState.HistoricalRoots()
+	hr2 := mSt.HistoricalRoots()
 	require.DeepEqual(t, hr1, hr2)
 
 	require.DeepSSZEqual(t, preForkState.Eth1Data(), mSt.Eth1Data())

beacon-chain/core/helpers/beacon_committee.go

@@ -18,6 +18,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/math"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -297,6 +298,9 @@ func verifyAssignmentEpoch(epoch primitives.Epoch, state state.BeaconState) erro
 // It verifies the validity of the epoch, then iterates through each slot in the epoch to determine the
 // proposer for that slot and assigns them accordingly.
 func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch primitives.Epoch) (map[primitives.ValidatorIndex][]primitives.Slot, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.ProposerAssignments")
+	defer span.End()
+
 	// Verify if the epoch is valid for assignment based on the provided state.
 	if err := verifyAssignmentEpoch(epoch, state); err != nil {
 		return nil, err
@@ -345,6 +349,9 @@ func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch pri
 // It retrieves active validator indices, determines the number of committees per slot, and computes
 // assignments for each validator based on their presence in the provided validators slice.
 func CommitteeAssignments(ctx context.Context, state state.BeaconState, epoch primitives.Epoch, validators []primitives.ValidatorIndex) (map[primitives.ValidatorIndex]*CommitteeAssignment, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.CommitteeAssignments")
+	defer span.End()
+
 	// Verify if the epoch is valid for assignment based on the provided state.
 	if err := verifyAssignmentEpoch(epoch, state); err != nil {
 		return nil, err

beacon-chain/core/helpers/randao.go

@@ -29,10 +29,13 @@ func Seed(state state.ReadOnlyBeaconState, epoch primitives.Epoch, domain [bls.D
 	if err != nil {
 		return [32]byte{}, err
 	}
-	seed := append(domain[:], bytesutil.Bytes8(uint64(epoch))...)
-	seed = append(seed, randaoMix...)
 
-	seed32 := hash.Hash(seed)
+	var seed [bls.DomainByteLength + 8 + 32]byte
+	copy(seed[0:], domain[:])
+	copy(seed[bls.DomainByteLength:], bytesutil.Bytes8(uint64(epoch)))
+	copy(seed[bls.DomainByteLength+8:], randaoMix)
+
+	seed32 := hash.Hash(seed[:])
 
 	return seed32, nil
 }

beacon-chain/core/peerdas/BUILD.bazel

@@ -0,0 +1,71 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "das_core.go",
+        "info.go",
+        "metrics.go",
+        "p2p_interface.go",
+        "reconstruction.go",
+        "util.go",
+        "validator.go",
+    ],
+    importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//cmd/beacon-chain/flags: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/primitives:go_default_library",
+        "//container/trie:go_default_library",
+        "//crypto/hash:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_hashicorp_golang_lru//:go_default_library",
+        "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+        "@org_golang_x_sync//errgroup:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "das_core_test.go",
+        "info_test.go",
+        "p2p_interface_test.go",
+        "reconstruction_test.go",
+        "utils_test.go",
+        "validator_test.go",
+    ],
+    deps = [
+        ":go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
+        "//beacon-chain/state/state-native:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
+)

beacon-chain/core/peerdas/das_core.go

@@ -0,0 +1,402 @@
+package peerdas
+
+import (
+	"encoding/binary"
+	"math"
+	"slices"
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/crypto/hash"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/holiman/uint256"
+	"github.com/pkg/errors"
+)
+
+var (
+	// Custom errors
+	ErrCustodyGroupTooLarge           = errors.New("custody group too large")
+	ErrCustodyGroupCountTooLarge      = errors.New("custody group count too large")
+	ErrMismatchSize                   = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
+	errWrongComputedCustodyGroupCount = errors.New("wrong computed custody group count, should never happen")
+
+	// maxUint256 is the maximum value of an uint256.
+	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
+)
+
+type CustodyType int
+
+const (
+	Target CustodyType = iota
+	Actual
+)
+
+// CustodyGroups computes the custody groups the node should participate in for custody.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#get_custody_groups
+func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error) {
+	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+
+	// Check if the custody group count is larger than the number of custody groups.
+	if custodyGroupCount > numberOfCustodyGroup {
+		return nil, ErrCustodyGroupCountTooLarge
+	}
+
+	// Shortcut if all custody groups are needed.
+	if custodyGroupCount == numberOfCustodyGroup {
+		custodyGroups := make([]uint64, 0, numberOfCustodyGroup)
+		for i := range numberOfCustodyGroup {
+			custodyGroups = append(custodyGroups, i)
+		}
+
+		return custodyGroups, nil
+	}
+
+	one := uint256.NewInt(1)
+
+	custodyGroupsMap := make(map[uint64]bool, custodyGroupCount)
+	custodyGroups := make([]uint64, 0, custodyGroupCount)
+	for currentId := new(uint256.Int).SetBytes(nodeId.Bytes()); uint64(len(custodyGroups)) < custodyGroupCount; {
+		// Convert to big endian bytes.
+		currentIdBytesBigEndian := currentId.Bytes32()
+
+		// Convert to little endian.
+		currentIdBytesLittleEndian := bytesutil.ReverseByteOrder(currentIdBytesBigEndian[:])
+
+		// Hash the result.
+		hashedCurrentId := hash.Hash(currentIdBytesLittleEndian)
+
+		// Get the custody group ID.
+		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroup
+
+		// Add the custody group to the map.
+		if !custodyGroupsMap[custodyGroup] {
+			custodyGroupsMap[custodyGroup] = true
+			custodyGroups = append(custodyGroups, custodyGroup)
+		}
+
+		if currentId.Cmp(maxUint256) == 0 {
+			// Overflow prevention.
+			currentId = uint256.NewInt(0)
+		} else {
+			// Increment the current ID.
+			currentId.Add(currentId, one)
+		}
+
+		// Sort the custody groups.
+		slices.Sort[[]uint64](custodyGroups)
+	}
+
+	// Final check.
+	if uint64(len(custodyGroups)) != custodyGroupCount {
+		return nil, errWrongComputedCustodyGroupCount
+	}
+
+	return custodyGroups, nil
+}
+
+// ComputeColumnsForCustodyGroup computes the columns for a given custody group.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#compute_columns_for_custody_group
+func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
+	beaconConfig := params.BeaconConfig()
+	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+
+	if custodyGroup >= numberOfCustodyGroup {
+		return nil, ErrCustodyGroupTooLarge
+	}
+
+	numberOfColumns := beaconConfig.NumberOfColumns
+
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroup
+
+	columns := make([]uint64, 0, columnsPerGroup)
+	for i := range columnsPerGroup {
+		column := numberOfCustodyGroup*i + custodyGroup
+		columns = append(columns, column)
+	}
+
+	return columns, nil
+}
+
+// DataColumnSidecars computes the data column sidecars from the signed block, cells and cell proofs.
+// The returned value contains pointers to function parameters.
+// (If the caller alterates `cellsAndProofs` afterwards, the returned value will be modified as well.)
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.3/specs/fulu/das-core.md#get_data_column_sidecars
+func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
+	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
+		return nil, nil
+	}
+
+	block := signedBlock.Block()
+	blockBody := block.Body()
+	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	if len(blobKzgCommitments) != len(cellsAndProofs) {
+		return nil, ErrMismatchSize
+	}
+
+	signedBlockHeader, err := signedBlock.Header()
+	if err != nil {
+		return nil, errors.Wrap(err, "signed block header")
+	}
+
+	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
+	if err != nil {
+		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
+	}
+
+	dataColumnSidecars, err := DataColumnsSidecarsFromItems(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidecars from items")
+	}
+
+	return dataColumnSidecars, nil
+}
+
+// DataColumnsSidecarsFromItems computes the data column sidecars from the signed block header, the blob KZG commiments,
+// the KZG commitment includion proofs and cells and cell proofs.
+// The returned value contains pointers to function parameters.
+// (If the caller alterates input parameters afterwards, the returned value will be modified as well.)
+func DataColumnsSidecarsFromItems(
+	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
+	blobKzgCommitments [][]byte,
+	kzgCommitmentsInclusionProof [][]byte,
+	cellsAndProofs []kzg.CellsAndProofs,
+) ([]*ethpb.DataColumnSidecar, error) {
+	start := time.Now()
+	if len(blobKzgCommitments) != len(cellsAndProofs) {
+		return nil, ErrMismatchSize
+	}
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	blobsCount := len(cellsAndProofs)
+	sidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
+	for columnIndex := range numberOfColumns {
+		column := make([]kzg.Cell, 0, blobsCount)
+		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
+
+		for rowIndex := range blobsCount {
+			cellsForRow := cellsAndProofs[rowIndex].Cells
+			proofsForRow := cellsAndProofs[rowIndex].Proofs
+
+			cell := cellsForRow[columnIndex]
+			column = append(column, cell)
+
+			kzgProof := proofsForRow[columnIndex]
+			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
+		}
+
+		columnBytes := make([][]byte, 0, blobsCount)
+		for i := range column {
+			columnBytes = append(columnBytes, column[i][:])
+		}
+
+		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
+		for _, kzgProof := range kzgProofOfColumn {
+			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, kzgProof[:])
+		}
+
+		sidecar := &ethpb.DataColumnSidecar{
+			Index:                        columnIndex,
+			Column:                       columnBytes,
+			KzgCommitments:               blobKzgCommitments,
+			KzgProofs:                    kzgProofOfColumnBytes,
+			SignedBlockHeader:            signedBlockHeader,
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+
+		sidecars = append(sidecars, sidecar)
+	}
+
+	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
+	return sidecars, nil
+}
+
+// ComputeCustodyGroupForColumn computes the custody group for a given column.
+// It is the reciprocal function of ComputeColumnsForCustodyGroup.
+func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
+	beaconConfig := params.BeaconConfig()
+	numberOfColumns := beaconConfig.NumberOfColumns
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
+
+	if columnIndex >= numberOfColumns {
+		return 0, ErrIndexTooLarge
+	}
+
+	return columnIndex % numberOfCustodyGroups, nil
+}
+
+// Blobs extract blobs from `dataColumnsSidecar`.
+// This can be seen as the reciprocal function of DataColumnSidecars.
+// `dataColumnsSidecar` needs to contain the datacolumns corresponding to the non-extended matrix,
+// else an error will be returned.
+// (`dataColumnsSidecar` can contain extra columns, but they will be ignored.)
+func Blobs(indices map[uint64]bool, dataColumnsSidecar []*ethpb.DataColumnSidecar) ([]*blocks.VerifiedROBlob, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	// Compute the number of needed columns, including the number of columns is odd case.
+	neededColumnCount := (numberOfColumns + 1) / 2
+
+	// Check if all needed columns are present.
+	sliceIndexFromColumnIndex := make(map[uint64]int, len(dataColumnsSidecar))
+	for i := range dataColumnsSidecar {
+		dataColumnSideCar := dataColumnsSidecar[i]
+		index := dataColumnSideCar.Index
+
+		if index < neededColumnCount {
+			sliceIndexFromColumnIndex[index] = i
+		}
+	}
+
+	actualColumnCount := uint64(len(sliceIndexFromColumnIndex))
+
+	// Get missing columns.
+	if actualColumnCount < neededColumnCount {
+		var missingColumnsSlice []uint64
+
+		for i := range neededColumnCount {
+			if _, ok := sliceIndexFromColumnIndex[i]; !ok {
+				missingColumnsSlice = append(missingColumnsSlice, i)
+			}
+		}
+
+		slices.Sort[[]uint64](missingColumnsSlice)
+		return nil, errors.Errorf("some columns are missing: %v", missingColumnsSlice)
+	}
+
+	// It is safe to retrieve the first column since we already checked that `dataColumnsSidecar` is not empty.
+	firstDataColumnSidecar := dataColumnsSidecar[0]
+
+	blobCount := uint64(len(firstDataColumnSidecar.Column))
+
+	// Check all colums have te same length.
+	for i := range dataColumnsSidecar {
+		if uint64(len(dataColumnsSidecar[i].Column)) != blobCount {
+			return nil, errors.Errorf("mismatch in the length of the data columns, expected %d, got %d", blobCount, len(dataColumnsSidecar[i].Column))
+		}
+	}
+
+	// Reconstruct verified RO blobs from columns.
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
+
+	// Populate and filter indices.
+	indicesSlice := populateAndFilterIndices(indices, blobCount)
+
+	for _, blobIndex := range indicesSlice {
+		var blob kzg.Blob
+
+		// Compute the content of the blob.
+		for columnIndex := range neededColumnCount {
+			sliceIndex, ok := sliceIndexFromColumnIndex[columnIndex]
+			if !ok {
+				return nil, errors.Errorf("missing column %d, this should never happen", columnIndex)
+			}
+
+			dataColumnSideCar := dataColumnsSidecar[sliceIndex]
+			cell := dataColumnSideCar.Column[blobIndex]
+
+			for i := range cell {
+				blob[columnIndex*kzg.BytesPerCell+uint64(i)] = cell[i]
+			}
+		}
+
+		// Retrieve the blob KZG commitment.
+		blobKZGCommitment := kzg.Commitment(firstDataColumnSidecar.KzgCommitments[blobIndex])
+
+		// Compute the blob KZG proof.
+		blobKzgProof, err := kzg.ComputeBlobKZGProof(&blob, blobKZGCommitment)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute blob KZG proof")
+		}
+
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    blobIndex,
+			Blob:                     blob[:],
+			KzgCommitment:            blobKZGCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        firstDataColumnSidecar.SignedBlockHeader,
+			CommitmentInclusionProof: firstDataColumnSidecar.KzgCommitmentsInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		if err != nil {
+			return nil, errors.Wrap(err, "new RO blob")
+		}
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	return verifiedROBlobs, nil
+}
+
+// CustodyGroupSamplingSize returns the number of custody groups the node should sample from.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#custody-sampling
+func (custodyInfo *CustodyInfo) CustodyGroupSamplingSize(ct CustodyType) uint64 {
+	custodyGroupCount := custodyInfo.TargetGroupCount.Get()
+
+	if ct == Actual {
+		custodyGroupCount = custodyInfo.ActualGroupCount()
+	}
+
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+	return max(samplesPerSlot, custodyGroupCount)
+}
+
+// CustodyColumns computes the custody columns from the custody groups.
+func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+
+	custodyGroupCount := len(custodyGroups)
+
+	// Compute the columns for each custody group.
+	columns := make(map[uint64]bool, custodyGroupCount)
+	for _, group := range custodyGroups {
+		if group >= numberOfCustodyGroups {
+			return nil, ErrCustodyGroupTooLarge
+		}
+
+		groupColumns, err := ComputeColumnsForCustodyGroup(group)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute columns for custody group")
+		}
+
+		for _, column := range groupColumns {
+			columns[column] = true
+		}
+	}
+
+	return columns, nil
+}
+
+// populateAndFilterIndices returns a sorted slices of indices, setting all indices if none are provided,
+// and filtering out indices higher than the blob count.
+func populateAndFilterIndices(indices map[uint64]bool, blobCount uint64) []uint64 {
+	// If no indices are provided, provide all blobs.
+	if len(indices) == 0 {
+		for i := range blobCount {
+			indices[i] = true
+		}
+	}
+
+	// Filter blobs index higher than the blob count.
+	indicesSlice := make([]uint64, 0, len(indices))
+	for i := range indices {
+		if i < blobCount {
+			indicesSlice = append(indicesSlice, i)
+		}
+	}
+
+	// Sort the indices.
+	slices.Sort[[]uint64](indicesSlice)
+
+	return indicesSlice
+}

beacon-chain/core/peerdas/das_core_test.go

@@ -0,0 +1,311 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/pkg/errors"
+)
+
+func TestCustodyGroups(t *testing.T) {
+	// The happy path is unit tested in spec tests.
+	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroup+1)
+	require.ErrorIs(t, err, peerdas.ErrCustodyGroupCountTooLarge)
+}
+
+func TestComputeColumnsForCustodyGroup(t *testing.T) {
+	// The happy path is unit tested in spec tests.
+	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroup)
+	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
+}
+
+func TestDataColumnSidecars(t *testing.T) {
+	t.Run("nil signed block", func(t *testing.T) {
+		var expected []*ethpb.DataColumnSidecar = nil
+		actual, err := peerdas.DataColumnSidecars(nil, []kzg.CellsAndProofs{})
+		require.NoError(t, err)
+
+		require.DeepSSZEqual(t, expected, actual)
+	})
+
+	t.Run("empty cells and proofs", func(t *testing.T) {
+		// Create a protobuf signed beacon block.
+		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		actual, err := peerdas.DataColumnSidecars(signedBeaconBlock, []kzg.CellsAndProofs{})
+		require.NoError(t, err)
+		require.IsNil(t, actual)
+	})
+
+	t.Run("sizes mismatch", func(t *testing.T) {
+		// Create a protobuf signed beacon block.
+		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs.
+		cellsAndProofs := make([]kzg.CellsAndProofs, 1)
+
+		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
+		require.ErrorIs(t, err, peerdas.ErrMismatchSize)
+	})
+}
+
+// --------------------------------------------------------------------------------------------------------------------------------------
+// DataColumnsSidecarsFromItems is tested as part of the DataColumnSidecars tests, in the TestDataColumnsSidecarsBlobsRoundtrip function.
+// --------------------------------------------------------------------------------------------------------------------------------------
+
+func TestComputeCustodyGroupForColumn(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.NumberOfColumns = 128
+	config.NumberOfCustodyGroups = 64
+	params.OverrideBeaconConfig(config)
+
+	t.Run("index too large", func(t *testing.T) {
+		_, err := peerdas.ComputeCustodyGroupForColumn(1_000_000)
+		require.ErrorIs(t, err, peerdas.ErrIndexTooLarge)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		expected := uint64(2)
+		actual, err := peerdas.ComputeCustodyGroupForColumn(2)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+
+		expected = uint64(3)
+		actual, err = peerdas.ComputeCustodyGroupForColumn(3)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+
+		expected = uint64(2)
+		actual, err = peerdas.ComputeCustodyGroupForColumn(66)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+
+		expected = uint64(3)
+		actual, err = peerdas.ComputeCustodyGroupForColumn(67)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+	})
+}
+
+func TestBlobs(t *testing.T) {
+	blobsIndice := map[uint64]bool{}
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	almostAllColumns := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns/2)
+	for i := uint64(2); i < numberOfColumns/2+2; i++ {
+		almostAllColumns = append(almostAllColumns, &ethpb.DataColumnSidecar{
+			Index: i,
+		})
+	}
+
+	testCases := []struct {
+		name     string
+		input    []*ethpb.DataColumnSidecar
+		expected []*blocks.VerifiedROBlob
+		err      error
+	}{
+		{
+			name:     "empty input",
+			input:    []*ethpb.DataColumnSidecar{},
+			expected: nil,
+			err:      errors.New("some columns are missing: [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63]"),
+		},
+		{
+			name:     "missing columns",
+			input:    almostAllColumns,
+			expected: nil,
+			err:      errors.New("some columns are missing: [0 1]"),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			actual, err := peerdas.Blobs(blobsIndice, tc.input)
+			if tc.err != nil {
+				require.Equal(t, tc.err.Error(), err.Error())
+			} else {
+				require.NoError(t, err)
+			}
+			require.DeepSSZEqual(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestDataColumnsSidecarsBlobsRoundtrip(t *testing.T) {
+	const blobCount = 5
+	blobsIndex := map[uint64]bool{}
+
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Create a protobuf signed beacon block.
+	signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+	// Generate random blobs and their corresponding commitments and proofs.
+	blobs := make([]kzg.Blob, 0, blobCount)
+	blobKzgCommitments := make([]*kzg.Commitment, 0, blobCount)
+	blobKzgProofs := make([]*kzg.Proof, 0, blobCount)
+
+	for blobIndex := range blobCount {
+		// Create a random blob.
+		blob := getRandBlob(int64(blobIndex))
+		blobs = append(blobs, blob)
+
+		// Generate a blobKZGCommitment for the blob.
+		blobKZGCommitment, proof, err := generateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+
+		blobKzgCommitments = append(blobKzgCommitments, blobKZGCommitment)
+		blobKzgProofs = append(blobKzgProofs, proof)
+	}
+
+	// Set the commitments into the block.
+	blobZkgCommitmentsBytes := make([][]byte, 0, blobCount)
+	for _, blobKZGCommitment := range blobKzgCommitments {
+		blobZkgCommitmentsBytes = append(blobZkgCommitmentsBytes, blobKZGCommitment[:])
+	}
+
+	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = blobZkgCommitmentsBytes
+
+	// Generate verified RO blobs.
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
+
+	// Create a signed beacon block from the protobuf.
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+	require.NoError(t, err)
+
+	commitmentInclusionProof, err := blocks.MerkleProofKZGCommitments(signedBeaconBlock.Block().Body())
+	require.NoError(t, err)
+
+	for blobIndex := range blobCount {
+		blob := blobs[blobIndex]
+		blobKZGCommitment := blobKzgCommitments[blobIndex]
+		blobKzgProof := blobKzgProofs[blobIndex]
+
+		// Get the signed beacon block header.
+		signedBeaconBlockHeader, err := signedBeaconBlock.Header()
+		require.NoError(t, err)
+
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    uint64(blobIndex),
+			Blob:                     blob[:],
+			KzgCommitment:            blobKZGCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        signedBeaconBlockHeader,
+			CommitmentInclusionProof: commitmentInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		require.NoError(t, err)
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	// Compute data columns sidecars from the signed beacon block and from the blobs.
+	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
+	dataColumnsSidecar, err := peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
+	require.NoError(t, err)
+
+	// Compute the blobs from the data columns sidecar.
+	roundtripBlobs, err := peerdas.Blobs(blobsIndex, dataColumnsSidecar)
+	require.NoError(t, err)
+
+	// Check that the blobs are the same.
+	require.DeepSSZEqual(t, verifiedROBlobs, roundtripBlobs)
+}
+
+func TestCustodyGroupSamplingSize(t *testing.T) {
+	testCases := []struct {
+		name                         string
+		custodyType                  peerdas.CustodyType
+		validatorsCustodyRequirement uint64
+		toAdvertiseCustodyGroupCount uint64
+		expected                     uint64
+	}{
+		{
+			name:                         "target, lower than samples per slot",
+			custodyType:                  peerdas.Target,
+			validatorsCustodyRequirement: 2,
+			expected:                     8,
+		},
+		{
+			name:                         "target, higher than samples per slot",
+			custodyType:                  peerdas.Target,
+			validatorsCustodyRequirement: 100,
+			expected:                     100,
+		},
+		{
+			name:                         "actual, lower than samples per slot",
+			custodyType:                  peerdas.Actual,
+			validatorsCustodyRequirement: 3,
+			toAdvertiseCustodyGroupCount: 4,
+			expected:                     8,
+		},
+		{
+			name:                         "actual, higher than samples per slot",
+			custodyType:                  peerdas.Actual,
+			validatorsCustodyRequirement: 100,
+			toAdvertiseCustodyGroupCount: 101,
+			expected:                     100,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Create a custody info.
+			custodyInfo := peerdas.CustodyInfo{}
+
+			// Set the validators custody requirement for target custody group count.
+			custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(tc.validatorsCustodyRequirement)
+
+			// Set the to advertise custody group count.
+			custodyInfo.ToAdvertiseGroupCount.Set(tc.toAdvertiseCustodyGroupCount)
+
+			// Compute the custody group sampling size.
+			actual := custodyInfo.CustodyGroupSamplingSize(tc.custodyType)
+
+			// Check the result.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestCustodyColumns(t *testing.T) {
+	t.Run("group too large", func(t *testing.T) {
+		_, err := peerdas.CustodyColumns([]uint64{1_000_000})
+		require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		input := []uint64{1, 2}
+		expected := map[uint64]bool{1: true, 2: true}
+
+		actual, err := peerdas.CustodyColumns(input)
+		require.NoError(t, err)
+		require.Equal(t, len(expected), len(actual))
+		for i := range actual {
+			require.Equal(t, expected[i], actual[i])
+		}
+	})
+}

beacon-chain/core/peerdas/info.go

@@ -0,0 +1,192 @@
+package peerdas
+
+import (
+	"encoding/binary"
+	"sync"
+
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	lru "github.com/hashicorp/golang-lru"
+	"github.com/pkg/errors"
+)
+
+// info contains all useful peerDAS related information regarding a peer.
+type (
+	info struct {
+		CustodyGroups      map[uint64]bool
+		CustodyColumns     map[uint64]bool
+		DataColumnsSubnets map[uint64]bool
+	}
+
+	targetCustodyGroupCount struct {
+		mut                          sync.RWMutex
+		validatorsCustodyRequirement uint64
+	}
+
+	toAdverstiseCustodyGroupCount struct {
+		mut   sync.RWMutex
+		value uint64
+	}
+
+	CustodyInfo struct {
+		// Mut is a mutex to be used by caller to ensure neither
+		// TargetCustodyGroupCount nor ToAdvertiseCustodyGroupCount are being modified.
+		// (This is not necessary to use this mutex for any data protection.)
+		Mut sync.RWMutex
+
+		// TargetGroupCount represents the target number of custody groups we should custody
+		// regarding the validators we are tracking.
+		TargetGroupCount targetCustodyGroupCount
+
+		// ToAdvertiseGroupCount represents the number of custody groups to advertise to the network.
+		ToAdvertiseGroupCount toAdverstiseCustodyGroupCount
+	}
+)
+
+const (
+	nodeInfoCacheSize   = 200
+	nodeInfoCachKeySize = 32 + 8
+)
+
+var (
+	nodeInfoCacheMut sync.Mutex
+	nodeInfoCache    *lru.Cache
+)
+
+// Info returns the peerDAS information for a given nodeID and custodyGroupCount.
+// It returns a boolean indicating if the peer info was already in the cache and an error if any.
+func Info(nodeID enode.ID, custodyGroupCount uint64) (*info, bool, error) {
+	// Create a new cache if it doesn't exist.
+	if err := createInfoCacheIfNeeded(); err != nil {
+		return nil, false, errors.Wrap(err, "create cache if needed")
+	}
+
+	// Compute the key.
+	key := computeInfoCacheKey(nodeID, custodyGroupCount)
+
+	// If the value is already in the cache, return it.
+	if value, ok := nodeInfoCache.Get(key); ok {
+		peerInfo, ok := value.(*info)
+		if !ok {
+			return nil, false, errors.New("failed to cast peer info (should never happen)")
+		}
+
+		return peerInfo, true, nil
+	}
+
+	// The peer info is not in the cache, compute it.
+	// Compute custody groups.
+	custodyGroups, err := CustodyGroups(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, false, errors.Wrap(err, "custody groups")
+	}
+
+	// Compute custody columns.
+	custodyColumns, err := CustodyColumns(custodyGroups)
+	if err != nil {
+		return nil, false, errors.Wrap(err, "custody columns")
+	}
+
+	// Compute data columns subnets.
+	dataColumnsSubnets := DataColumnSubnets(custodyColumns)
+
+	// Convert the custody groups to a map.
+	custodyGroupsMap := make(map[uint64]bool, len(custodyGroups))
+	for _, group := range custodyGroups {
+		custodyGroupsMap[group] = true
+	}
+
+	result := &info{
+		CustodyGroups:      custodyGroupsMap,
+		CustodyColumns:     custodyColumns,
+		DataColumnsSubnets: dataColumnsSubnets,
+	}
+
+	// Add the result to the cache.
+	nodeInfoCache.Add(key, result)
+
+	return result, false, nil
+}
+
+// ActualGroupCount returns the actual custody group count.
+func (custodyInfo *CustodyInfo) ActualGroupCount() uint64 {
+	return min(custodyInfo.TargetGroupCount.Get(), custodyInfo.ToAdvertiseGroupCount.Get())
+}
+
+// CustodyGroupCount returns the number of groups we should participate in for custody.
+func (tcgc *targetCustodyGroupCount) Get() uint64 {
+	// If subscribed to all subnets, return the number of custody groups.
+	if flags.Get().SubscribeToAllSubnets {
+		return params.BeaconConfig().NumberOfCustodyGroups
+	}
+
+	tcgc.mut.RLock()
+	defer tcgc.mut.RUnlock()
+
+	// If no validators are tracked, return the default custody requirement.
+	if tcgc.validatorsCustodyRequirement == 0 {
+		return params.BeaconConfig().CustodyRequirement
+	}
+
+	// Return the validators custody requirement.
+	return tcgc.validatorsCustodyRequirement
+}
+
+// setValidatorsCustodyRequirement sets the validators custody requirement.
+func (tcgc *targetCustodyGroupCount) SetValidatorsCustodyRequirement(value uint64) {
+	tcgc.mut.Lock()
+	defer tcgc.mut.Unlock()
+
+	tcgc.validatorsCustodyRequirement = value
+}
+
+// Get returns the to advertise custody group count.
+func (tacgc *toAdverstiseCustodyGroupCount) Get() uint64 {
+	// If subscribed to all subnets, return the number of custody groups.
+	if flags.Get().SubscribeToAllSubnets {
+		return params.BeaconConfig().NumberOfCustodyGroups
+	}
+
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+
+	tacgc.mut.RLock()
+	defer tacgc.mut.RUnlock()
+
+	return max(tacgc.value, custodyRequirement)
+}
+
+// Set sets the to advertise custody group count.
+func (tacgc *toAdverstiseCustodyGroupCount) Set(value uint64) {
+	tacgc.mut.Lock()
+	defer tacgc.mut.Unlock()
+
+	tacgc.value = value
+}
+
+// createInfoCacheIfNeeded creates a new cache if it doesn't exist.
+func createInfoCacheIfNeeded() error {
+	nodeInfoCacheMut.Lock()
+	defer nodeInfoCacheMut.Unlock()
+
+	if nodeInfoCache == nil {
+		c, err := lru.New(nodeInfoCacheSize)
+		if err != nil {
+			return errors.Wrap(err, "lru new")
+		}
+
+		nodeInfoCache = c
+	}
+
+	return nil
+}
+
+// computeInfoCacheKey returns a unique key for a node and its custodyGroupCount.
+func computeInfoCacheKey(nodeID enode.ID, custodyGroupCount uint64) [nodeInfoCachKeySize]byte {
+	var key [nodeInfoCachKeySize]byte
+
+	copy(key[:32], nodeID[:])
+	binary.BigEndian.PutUint64(key[32:], custodyGroupCount)
+
+	return key
+}

beacon-chain/core/peerdas/info_test.go

@@ -0,0 +1,133 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+func TestInfo(t *testing.T) {
+	nodeID := enode.ID{}
+	custodyGroupCount := uint64(7)
+
+	expectedCustodyGroup := map[uint64]bool{1: true, 17: true, 19: true, 42: true, 75: true, 87: true, 102: true}
+	expectedCustodyColumns := map[uint64]bool{1: true, 17: true, 19: true, 42: true, 75: true, 87: true, 102: true}
+	expectedDataColumnsSubnets := map[uint64]bool{1: true, 17: true, 19: true, 42: true, 75: true, 87: true, 102: true}
+
+	for _, cached := range []bool{false, true} {
+		actual, ok, err := peerdas.Info(nodeID, custodyGroupCount)
+		require.NoError(t, err)
+		require.Equal(t, cached, ok)
+		require.DeepEqual(t, expectedCustodyGroup, actual.CustodyGroups)
+		require.DeepEqual(t, expectedCustodyColumns, actual.CustodyColumns)
+		require.DeepEqual(t, expectedDataColumnsSubnets, actual.DataColumnsSubnets)
+	}
+}
+
+func TestTargetCustodyGroupCount(t *testing.T) {
+	testCases := []struct {
+		name                         string
+		subscribeToAllSubnets        bool
+		validatorsCustodyRequirement uint64
+		expected                     uint64
+	}{
+		{
+			name:                         "subscribed to all subnets",
+			subscribeToAllSubnets:        true,
+			validatorsCustodyRequirement: 100,
+			expected:                     128,
+		},
+		{
+			name:                         "no validators attached",
+			subscribeToAllSubnets:        false,
+			validatorsCustodyRequirement: 0,
+			expected:                     4,
+		},
+		{
+			name:                         "some validators attached",
+			subscribeToAllSubnets:        false,
+			validatorsCustodyRequirement: 100,
+			expected:                     100,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Subscribe to all subnets if needed.
+			if tc.subscribeToAllSubnets {
+				resetFlags := flags.Get()
+				gFlags := new(flags.GlobalFlags)
+				gFlags.SubscribeToAllSubnets = true
+				flags.Init(gFlags)
+				defer flags.Init(resetFlags)
+			}
+
+			var custodyInfo peerdas.CustodyInfo
+
+			// Set the validators custody requirement.
+			custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(tc.validatorsCustodyRequirement)
+
+			// Get the target custody group count.
+			actual := custodyInfo.TargetGroupCount.Get()
+
+			// Compare the expected and actual values.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestToAdvertiseCustodyGroupCount(t *testing.T) {
+	testCases := []struct {
+		name                         string
+		subscribeToAllSubnets        bool
+		toAdvertiseCustodyGroupCount uint64
+		expected                     uint64
+	}{
+		{
+			name:                         "subscribed to all subnets",
+			subscribeToAllSubnets:        true,
+			toAdvertiseCustodyGroupCount: 100,
+			expected:                     128,
+		},
+		{
+			name:                         "higher than custody requirement",
+			subscribeToAllSubnets:        false,
+			toAdvertiseCustodyGroupCount: 100,
+			expected:                     100,
+		},
+		{
+			name:                         "lower than custody requirement",
+			subscribeToAllSubnets:        false,
+			toAdvertiseCustodyGroupCount: 1,
+			expected:                     4,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Subscribe to all subnets if needed.
+			if tc.subscribeToAllSubnets {
+				resetFlags := flags.Get()
+				gFlags := new(flags.GlobalFlags)
+				gFlags.SubscribeToAllSubnets = true
+				flags.Init(gFlags)
+				defer flags.Init(resetFlags)
+			}
+
+			// Create a custody info.
+			var custodyInfo peerdas.CustodyInfo
+
+			// Set the to advertise custody group count.
+			custodyInfo.ToAdvertiseGroupCount.Set(tc.toAdvertiseCustodyGroupCount)
+
+			// Get the to advertise custody group count.
+			actual := custodyInfo.ToAdvertiseGroupCount.Get()
+
+			// Compare the expected and actual values.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}

beacon-chain/core/peerdas/metrics.go

@@ -0,0 +1,14 @@
+package peerdas
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var dataColumnComputationTime = promauto.NewHistogram(
+	prometheus.HistogramOpts{
+		Name:    "beacon_data_column_sidecar_computation_milliseconds",
+		Help:    "Captures the time taken to compute data column sidecars from blobs.",
+		Buckets: []float64{100, 250, 500, 750, 1000, 1500, 2000, 4000, 8000, 12000, 16000},
+	},
+)

beacon-chain/core/peerdas/p2p_interface.go

@@ -0,0 +1,162 @@
+package peerdas
+
+import (
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	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/container/trie"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/pkg/errors"
+)
+
+const (
+	CustodyGroupCountEnrKey = "cgc"
+	kzgPosition             = 11 // The index of the KZG commitment list in the Body
+)
+
+var (
+	ErrIndexTooLarge               = errors.New("column index is larger than the specified columns count")
+	ErrNoKzgCommitments            = errors.New("no KZG commitments found")
+	ErrMismatchLength              = errors.New("mismatch in the length of the column, commitments or proofs")
+	ErrInvalidKZGProof             = errors.New("invalid KZG proof")
+	ErrBadRootLength               = errors.New("bad root length")
+	ErrInvalidInclusionProof       = errors.New("invalid inclusion proof")
+	ErrRecordNil                   = errors.New("record is nil")
+	ErrNilBlockHeader              = errors.New("nil beacon block header")
+	ErrCannotLoadCustodyGroupCount = errors.New("cannot load the custody group count from peer")
+)
+
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#custody-group-count
+type Cgc uint64
+
+func (Cgc) ENRKey() string { return CustodyGroupCountEnrKey }
+
+// VerifyDataColumnSidecar verifies if the data column sidecar is valid.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar
+func VerifyDataColumnSidecar(sidecar blocks.RODataColumn) error {
+	// The sidecar index must be within the valid range.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	if sidecar.Index >= numberOfColumns {
+		return ErrIndexTooLarge
+	}
+
+	// A sidecar for zero blobs is invalid.
+	if len(sidecar.KzgCommitments) == 0 {
+		return ErrNoKzgCommitments
+	}
+
+	// The column length must be equal to the number of commitments/proofs.
+	if len(sidecar.Column) != len(sidecar.KzgCommitments) || len(sidecar.Column) != len(sidecar.KzgProofs) {
+		return ErrMismatchLength
+	}
+
+	return nil
+}
+
+// VerifyDataColumnsSidecarKZGProofs verifies if the KZG proofs are correct.
+// Note: We are slightly deviating from the specification here:
+// The specification verifies the KZG proofs for each sidecar separately,
+// while we are verifying all the KZG proofs from multiple sidecars in a batch.
+// This is done to improve performance since the internal KZG library is way more
+// efficient when verifying in batch.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar_kzg_proofs
+func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) error {
+	// Compute the total count.
+	count := 0
+	for _, sidecar := range sidecars {
+		count += len(sidecar.Column)
+	}
+
+	commitments := make([]kzg.Bytes48, 0, count)
+	indices := make([]uint64, 0, count)
+	cells := make([]kzg.Cell, 0, count)
+	proofs := make([]kzg.Bytes48, 0, count)
+
+	for _, sidecar := range sidecars {
+		for i := range sidecar.Column {
+			commitments = append(commitments, kzg.Bytes48(sidecar.KzgCommitments[i]))
+			indices = append(indices, sidecar.Index)
+			cells = append(cells, kzg.Cell(sidecar.Column[i]))
+			proofs = append(proofs, kzg.Bytes48(sidecar.KzgProofs[i]))
+		}
+	}
+
+	// Batch verify that the cells match the corresponding commitments and proofs.
+	verified, err := kzg.VerifyCellKZGProofBatch(commitments, indices, cells, proofs)
+	if err != nil {
+		return errors.Wrap(err, "verify cell KZG proof batch")
+	}
+
+	if !verified {
+		return ErrInvalidKZGProof
+	}
+
+	return nil
+}
+
+// VerifyDataColumnSidecarInclusionProof verifies if the given KZG commitments included in the given beacon block.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar_inclusion_proof
+func VerifyDataColumnSidecarInclusionProof(sidecar blocks.RODataColumn) error {
+	if sidecar.SignedBlockHeader == nil || sidecar.SignedBlockHeader.Header == nil {
+		return ErrNilBlockHeader
+	}
+
+	root := sidecar.SignedBlockHeader.Header.BodyRoot
+	if len(root) != fieldparams.RootLength {
+		return ErrBadRootLength
+	}
+
+	leaves := blocks.LeavesFromCommitments(sidecar.KzgCommitments)
+
+	sparse, err := trie.GenerateTrieFromItems(leaves, fieldparams.LogMaxBlobCommitments)
+	if err != nil {
+		return errors.Wrap(err, "generate trie from items")
+	}
+
+	hashTreeRoot, err := sparse.HashTreeRoot()
+	if err != nil {
+		return errors.Wrap(err, "hash tree root")
+	}
+
+	verified := trie.VerifyMerkleProof(root, hashTreeRoot[:], kzgPosition, sidecar.KzgCommitmentsInclusionProof)
+	if !verified {
+		return ErrInvalidInclusionProof
+	}
+
+	return nil
+}
+
+// ComputeSubnetForDataColumnSidecar computes the subnet for a data column sidecar.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
+func ComputeSubnetForDataColumnSidecar(columnIndex uint64) uint64 {
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+	return columnIndex % dataColumnSidecarSubnetCount
+}
+
+// DataColumnSubnets computes the subnets for the data columns.
+func DataColumnSubnets(dataColumns map[uint64]bool) map[uint64]bool {
+	subnets := make(map[uint64]bool, len(dataColumns))
+
+	for column := range dataColumns {
+		subnet := ComputeSubnetForDataColumnSidecar(column)
+		subnets[subnet] = true
+	}
+
+	return subnets
+}
+
+// CustodyGroupCountFromRecord extracts the custody group count from an ENR record.
+func CustodyGroupCountFromRecord(record *enr.Record) (uint64, error) {
+	if record == nil {
+		return 0, ErrRecordNil
+	}
+
+	// Load the `cgc`
+	var cgc Cgc
+	if err := record.Load(&cgc); err != nil {
+		return 0, ErrCannotLoadCustodyGroupCount
+	}
+
+	return uint64(cgc), nil
+}

beacon-chain/core/peerdas/p2p_interface_test.go

@@ -0,0 +1,304 @@
+package peerdas_test
+
+import (
+	"crypto/rand"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+)
+
+func TestVerifyDataColumnSidecar(t *testing.T) {
+	t.Run("index too large", func(t *testing.T) {
+		roSidecar := createTestSidecar(t, 1_000_000, nil, nil, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrIndexTooLarge)
+	})
+
+	t.Run("no commitments", func(t *testing.T) {
+		roSidecar := createTestSidecar(t, 0, nil, nil, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrNoKzgCommitments)
+	})
+
+	t.Run("KZG commitments size mismatch", func(t *testing.T) {
+		kzgCommitments := make([][]byte, 1)
+		roSidecar := createTestSidecar(t, 0, nil, kzgCommitments, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrMismatchLength)
+	})
+
+	t.Run("KZG proofs size mismatch", func(t *testing.T) {
+		column, kzgCommitments := make([][]byte, 1), make([][]byte, 1)
+		roSidecar := createTestSidecar(t, 0, column, kzgCommitments, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrMismatchLength)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		column, kzgCommitments, kzgProofs := make([][]byte, 1), make([][]byte, 1), make([][]byte, 1)
+		roSidecar := createTestSidecar(t, 0, column, kzgCommitments, kzgProofs)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.NoError(t, err)
+	})
+}
+
+func TestVerifyDataColumnSidecarKZGProofs(t *testing.T) {
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	generateSidecars := func(t *testing.T) []*ethpb.DataColumnSidecar {
+		const blobCount = int64(6)
+
+		dbBlock := util.NewBeaconBlockDeneb()
+
+		commitments := make([][]byte, 0, blobCount)
+		blobs := make([]kzg.Blob, 0, blobCount)
+
+		for i := range blobCount {
+			blob := getRandBlob(i)
+			commitment, _, err := generateCommitmentAndProof(&blob)
+			require.NoError(t, err)
+
+			commitments = append(commitments, commitment[:])
+			blobs = append(blobs, blob)
+		}
+
+		dbBlock.Block.Body.BlobKzgCommitments = commitments
+		sBlock, err := blocks.NewSignedBeaconBlock(dbBlock)
+		require.NoError(t, err)
+
+		cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
+		sidecars, err := peerdas.DataColumnSidecars(sBlock, cellsAndProofs)
+		require.NoError(t, err)
+
+		return sidecars
+	}
+
+	generateRODataColumnSidecars := func(t *testing.T, sidecars []*ethpb.DataColumnSidecar) []blocks.RODataColumn {
+		roDataColumnSidecars := make([]blocks.RODataColumn, 0, len(sidecars))
+		for _, sidecar := range sidecars {
+			roCol, err := blocks.NewRODataColumn(sidecar)
+			require.NoError(t, err)
+
+			roDataColumnSidecars = append(roDataColumnSidecars, roCol)
+		}
+
+		return roDataColumnSidecars
+	}
+
+	t.Run("invalid proof", func(t *testing.T) {
+		sidecars := generateSidecars(t)
+		sidecars[0].Column[0][0]++ // It is OK to overflow
+		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
+
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		require.ErrorIs(t, err, peerdas.ErrInvalidKZGProof)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		sidecars := generateSidecars(t)
+		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
+
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		require.NoError(t, err)
+	})
+}
+
+func Test_VerifyKZGInclusionProofColumn(t *testing.T) {
+	const (
+		blobCount   = 3
+		columnIndex = 0
+	)
+
+	// Generate random KZG commitments `blobCount` blobs.
+	kzgCommitments := make([][]byte, blobCount)
+
+	for i := 0; i < blobCount; i++ {
+		kzgCommitments[i] = make([]byte, 48)
+		_, err := rand.Read(kzgCommitments[i])
+		require.NoError(t, err)
+	}
+
+	pbBody := &ethpb.BeaconBlockBodyDeneb{
+		RandaoReveal: make([]byte, 96),
+		Eth1Data: &ethpb.Eth1Data{
+			DepositRoot: make([]byte, fieldparams.RootLength),
+			BlockHash:   make([]byte, fieldparams.RootLength),
+		},
+		Graffiti: make([]byte, 32),
+		SyncAggregate: &ethpb.SyncAggregate{
+			SyncCommitteeBits:      make([]byte, fieldparams.SyncAggregateSyncCommitteeBytesLength),
+			SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+		},
+		ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, 20),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, 256),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+		},
+		BlobKzgCommitments: kzgCommitments,
+	}
+
+	root, err := pbBody.HashTreeRoot()
+	require.NoError(t, err)
+
+	body, err := blocks.NewBeaconBlockBody(pbBody)
+	require.NoError(t, err)
+
+	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(body)
+	require.NoError(t, err)
+
+	testCases := []struct {
+		name              string
+		expectedError     error
+		dataColumnSidecar *ethpb.DataColumnSidecar
+	}{
+		{
+			name:              "nilSignedBlockHeader",
+			expectedError:     peerdas.ErrNilBlockHeader,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{},
+		},
+		{
+			name:          "nilHeader",
+			expectedError: peerdas.ErrNilBlockHeader,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{},
+			},
+		},
+		{
+			name:          "invalidBodyRoot",
+			expectedError: peerdas.ErrBadRootLength,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+					Header: &ethpb.BeaconBlockHeader{},
+				},
+			},
+		},
+		{
+			name:          "unverifiedMerkleProof",
+			expectedError: peerdas.ErrInvalidInclusionProof,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+					Header: &ethpb.BeaconBlockHeader{
+						BodyRoot: make([]byte, 32),
+					},
+				},
+				KzgCommitments: kzgCommitments,
+			},
+		},
+		{
+			name:          "nominal",
+			expectedError: nil,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				KzgCommitments: kzgCommitments,
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+					Header: &ethpb.BeaconBlockHeader{
+						BodyRoot: root[:],
+					},
+				},
+				KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			roDataColumn := blocks.RODataColumn{DataColumnSidecar: tc.dataColumnSidecar}
+			err = peerdas.VerifyDataColumnSidecarInclusionProof(roDataColumn)
+			if tc.expectedError == nil {
+				require.NoError(t, err)
+				return
+			}
+
+			require.ErrorIs(t, tc.expectedError, err)
+		})
+	}
+}
+
+func TestComputeSubnetForDataColumnSidecar(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.DataColumnSidecarSubnetCount = 128
+	params.OverrideBeaconConfig(config)
+
+	require.Equal(t, uint64(0), peerdas.ComputeSubnetForDataColumnSidecar(0))
+	require.Equal(t, uint64(1), peerdas.ComputeSubnetForDataColumnSidecar(1))
+	require.Equal(t, uint64(0), peerdas.ComputeSubnetForDataColumnSidecar(128))
+	require.Equal(t, uint64(1), peerdas.ComputeSubnetForDataColumnSidecar(129))
+}
+
+func TestDataColumnSubnets(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.DataColumnSidecarSubnetCount = 128
+	params.OverrideBeaconConfig(config)
+
+	input := map[uint64]bool{0: true, 1: true, 128: true, 129: true, 131: true}
+	expected := map[uint64]bool{0: true, 1: true, 3: true}
+	actual := peerdas.DataColumnSubnets(input)
+
+	require.Equal(t, len(expected), len(actual))
+	for k, v := range expected {
+		require.Equal(t, v, actual[k])
+	}
+}
+
+func TestCustodyGroupCountFromRecord(t *testing.T) {
+	t.Run("nil record", func(t *testing.T) {
+		_, err := peerdas.CustodyGroupCountFromRecord(nil)
+		require.ErrorIs(t, err, peerdas.ErrRecordNil)
+	})
+
+	t.Run("no cgc", func(t *testing.T) {
+		_, err := peerdas.CustodyGroupCountFromRecord(&enr.Record{})
+		require.ErrorIs(t, err, peerdas.ErrCannotLoadCustodyGroupCount)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		const expected uint64 = 7
+
+		record := &enr.Record{}
+		record.Set(peerdas.Cgc(expected))
+
+		actual, err := peerdas.CustodyGroupCountFromRecord(record)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+	})
+}
+
+func createTestSidecar(t *testing.T, index uint64, column, kzgCommitments, kzgProofs [][]byte) blocks.RODataColumn {
+	pbSignedBeaconBlock := util.NewBeaconBlockDeneb()
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(pbSignedBeaconBlock)
+	require.NoError(t, err)
+
+	signedBlockHeader, err := signedBeaconBlock.Header()
+	require.NoError(t, err)
+
+	sidecar := &ethpb.DataColumnSidecar{
+		Index:             index,
+		Column:            column,
+		KzgCommitments:    kzgCommitments,
+		KzgProofs:         kzgProofs,
+		SignedBlockHeader: signedBlockHeader,
+	}
+
+	roSidecar, err := blocks.NewRODataColumn(sidecar)
+	require.NoError(t, err)
+
+	return roSidecar
+}

beacon-chain/core/peerdas/reconstruction.go

@@ -0,0 +1,76 @@
+package peerdas
+
+import (
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/pkg/errors"
+	"golang.org/x/sync/errgroup"
+)
+
+// CanSelfReconstruct returns true if the node can self-reconstruct all the data columns from its custody group count.
+func CanSelfReconstruct(custodyGroupCount uint64) bool {
+	total := params.BeaconConfig().NumberOfCustodyGroups
+	// If total is odd, then we need total / 2 + 1 columns to reconstruct.
+	// If total is even, then we need total / 2 columns to reconstruct.
+	return custodyGroupCount >= (total+1)/2
+}
+
+// RecoverCellsAndProofs recovers the cells and proofs from the data column sidecars.
+func RecoverCellsAndProofs(dataColumnSideCars []*ethpb.DataColumnSidecar) ([]kzg.CellsAndProofs, error) {
+	var wg errgroup.Group
+
+	dataColumnSideCarsCount := len(dataColumnSideCars)
+
+	if dataColumnSideCarsCount == 0 {
+		return nil, errors.New("no data column sidecars")
+	}
+
+	// Check if all columns have the same length.
+	blobCount := len(dataColumnSideCars[0].Column)
+	for _, sidecar := range dataColumnSideCars {
+		length := len(sidecar.Column)
+
+		if length != blobCount {
+			return nil, errors.New("columns do not have the same length")
+		}
+	}
+
+	// Recover cells and compute proofs in parallel.
+	recoveredCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+
+	for blobIndex := 0; blobIndex < blobCount; blobIndex++ {
+		bIndex := blobIndex
+		wg.Go(func() error {
+			cellsIndices := make([]uint64, 0, dataColumnSideCarsCount)
+			cells := make([]kzg.Cell, 0, dataColumnSideCarsCount)
+
+			for _, sidecar := range dataColumnSideCars {
+				// Build the cell indices.
+				cellsIndices = append(cellsIndices, sidecar.Index)
+
+				// Get the cell.
+				column := sidecar.Column
+				cell := column[bIndex]
+
+				cells = append(cells, kzg.Cell(cell))
+			}
+
+			// Recover the cells and proofs for the corresponding blob
+			cellsAndProofs, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
+
+			if err != nil {
+				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", bIndex)
+			}
+
+			recoveredCellsAndProofs[bIndex] = cellsAndProofs
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, err
+	}
+
+	return recoveredCellsAndProofs, nil
+}

beacon-chain/core/peerdas/reconstruction_test.go

@@ -0,0 +1,57 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestCanSelfReconstruct(t *testing.T) {
+	testCases := []struct {
+		name                       string
+		totalNumberOfCustodyGroups uint64
+		custodyNumberOfGroups      uint64
+		expected                   bool
+	}{
+		{
+			name:                       "totalNumberOfCustodyGroups=64, custodyNumberOfGroups=31",
+			totalNumberOfCustodyGroups: 64,
+			custodyNumberOfGroups:      31,
+			expected:                   false,
+		},
+		{
+			name:                       "totalNumberOfCustodyGroups=64, custodyNumberOfGroups=32",
+			totalNumberOfCustodyGroups: 64,
+			custodyNumberOfGroups:      32,
+			expected:                   true,
+		},
+		{
+			name:                       "totalNumberOfCustodyGroups=65, custodyNumberOfGroups=32",
+			totalNumberOfCustodyGroups: 65,
+			custodyNumberOfGroups:      32,
+			expected:                   false,
+		},
+		{
+			name:                       "totalNumberOfCustodyGroups=63, custodyNumberOfGroups=33",
+			totalNumberOfCustodyGroups: 65,
+			custodyNumberOfGroups:      33,
+			expected:                   true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Set the total number of columns.
+			params.SetupTestConfigCleanup(t)
+			cfg := params.BeaconConfig().Copy()
+			cfg.NumberOfCustodyGroups = tc.totalNumberOfCustodyGroups
+			params.OverrideBeaconConfig(cfg)
+
+			// Check if reconstuction is possible.
+			actual := peerdas.CanSelfReconstruct(tc.custodyNumberOfGroups)
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}

beacon-chain/core/peerdas/util.go

@@ -0,0 +1,54 @@
+package peerdas
+
+import (
+	"fmt"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/pkg/errors"
+)
+
+// ConstructDataColumnSidecars constructs data column sidecars from a block, blobs and their cell proofs.
+// This is a convenience method as blob and cell proofs are common inputs.
+func ConstructDataColumnSidecars(block interfaces.SignedBeaconBlock, blobs [][]byte, cellProofs [][]byte) ([]*ethpb.DataColumnSidecar, error) {
+	// Check if the block is at least a Fulu block.
+	if block.Version() < version.Fulu {
+		return nil, nil
+	}
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	if uint64(len(blobs))*numberOfColumns != uint64(len(cellProofs)) {
+		return nil, fmt.Errorf("number of blobs and cell proofs do not match: %d * %d != %d", len(blobs), numberOfColumns, len(cellProofs))
+	}
+
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, len(blobs))
+
+	for i, blob := range blobs {
+		var b kzg.Blob
+		copy(b[:], blob)
+		cells, err := kzg.ComputeCells(&b)
+		if err != nil {
+			return nil, err
+		}
+
+		var proofs []kzg.Proof
+		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+			proofs = append(proofs, kzg.Proof(cellProofs[idx]))
+		}
+
+		cellsAndProofs = append(cellsAndProofs, kzg.CellsAndProofs{
+			Cells:  cells,
+			Proofs: proofs,
+		})
+	}
+
+	dataColumnSidecars, err := DataColumnSidecars(block, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidcars")
+	}
+
+	return dataColumnSidecars, nil
+}

beacon-chain/core/peerdas/utils_test.go

@@ -0,0 +1,57 @@
+package peerdas_test
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/sirupsen/logrus"
+)
+
+func generateCommitmentAndProof(blob *kzg.Blob) (*kzg.Commitment, *kzg.Proof, error) {
+	commitment, err := kzg.BlobToKZGCommitment(blob)
+	if err != nil {
+		return nil, nil, err
+	}
+	proof, err := kzg.ComputeBlobKZGProof(blob, commitment)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &commitment, &proof, err
+}
+
+// Returns a random blob using the passed seed as entropy
+func getRandBlob(seed int64) kzg.Blob {
+	var blob kzg.Blob
+	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
+		fieldElementBytes := getRandFieldElement(seed + int64(i))
+		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
+	}
+	return blob
+}
+
+// Returns a serialized random field element in big-endian
+func getRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}

beacon-chain/core/peerdas/validator.go

@@ -0,0 +1,30 @@
+package peerdas
+
+import (
+	beaconState "github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+// ValidatorsCustodyRequirement returns the number of custody groups regarding the validator indices attached to the beacon node.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/validator.md#validator-custody
+func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validatorsIndex map[primitives.ValidatorIndex]bool) (uint64, error) {
+	totalNodeBalance := uint64(0)
+	for index := range validatorsIndex {
+		validator, err := state.ValidatorAtIndexReadOnly(index)
+		if err != nil {
+			return 0, errors.Wrapf(err, "validator at index %v", index)
+		}
+
+		totalNodeBalance += validator.EffectiveBalance()
+	}
+
+	beaconConfig := params.BeaconConfig()
+	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	validatorCustodyRequirement := beaconConfig.ValidatorCustodyRequirement
+	balancePerAdditionalCustodyGroup := beaconConfig.BalancePerAdditionalCustodyGroup
+
+	count := totalNodeBalance / balancePerAdditionalCustodyGroup
+	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroup), nil
+}

beacon-chain/core/peerdas/validator_test.go

@@ -0,0 +1,55 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestValidatorsCustodyRequirement(t *testing.T) {
+	testCases := []struct {
+		name     string
+		count    uint64
+		expected uint64
+	}{
+		{name: "0 validators", count: 0, expected: 8},
+		{name: "1 validator", count: 1, expected: 8},
+		{name: "8 validators", count: 8, expected: 8},
+		{name: "9 validators", count: 9, expected: 9},
+		{name: "100 validators", count: 100, expected: 100},
+		{name: "128 validators", count: 128, expected: 128},
+		{name: "129 validators", count: 129, expected: 128},
+		{name: "1000 validators", count: 1000, expected: 128},
+	}
+
+	const balance = uint64(32_000_000_000)
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			validators := make([]*ethpb.Validator, 0, tc.count)
+			for range tc.count {
+				validator := &ethpb.Validator{
+					EffectiveBalance: balance,
+				}
+
+				validators = append(validators, validator)
+			}
+
+			validatorsIndex := make(map[primitives.ValidatorIndex]bool)
+			for i := range tc.count {
+				validatorsIndex[primitives.ValidatorIndex(i)] = true
+			}
+
+			beaconState, err := state_native.InitializeFromProtoFulu(&ethpb.BeaconStateElectra{Validators: validators})
+			require.NoError(t, err)
+
+			actual, err := peerdas.ValidatorsCustodyRequirement(beaconState, validatorsIndex)
+			require.NoError(t, err)
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}

beacon-chain/core/signing/signing_root.go

@@ -247,7 +247,7 @@ func ComputeDomain(domainType [DomainByteLength]byte, forkVersion, genesisValida
 
 // This returns the bls domain given by the domain type and fork data root.
 func domain(domainType [DomainByteLength]byte, forkDataRoot []byte) []byte {
-	var b []byte
+	b := make([]byte, 0, 32)
 	b = append(b, domainType[:4]...)
 	b = append(b, forkDataRoot[:28]...)
 	return b

beacon-chain/db/kv/BUILD.bazel

@@ -59,7 +59,7 @@ go_library(
         "//runtime/version:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_dgraph_io_ristretto//:go_default_library",
+        "@com_github_dgraph_io_ristretto_v2//:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_golang_snappy//:go_default_library",

beacon-chain/db/kv/blocks.go

@@ -40,7 +40,7 @@ func (s *Store) Block(ctx context.Context, blockRoot [32]byte) (interfaces.ReadO
 
 func (s *Store) getBlock(ctx context.Context, blockRoot [32]byte, tx *bolt.Tx) (interfaces.ReadOnlySignedBeaconBlock, error) {
 	if v, ok := s.blockCache.Get(string(blockRoot[:])); v != nil && ok {
-		return v.(interfaces.ReadOnlySignedBeaconBlock), nil
+		return v, nil
 	}
 	// This method allows the caller to pass in its tx if one is already open.
 	// Or if a nil value is used, a transaction will be managed intenally.

beacon-chain/db/kv/kv.go

@@ -13,8 +13,10 @@ import (
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/io/file"
-	"github.com/dgraph-io/ristretto"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/dgraph-io/ristretto/v2"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -86,8 +88,8 @@ var blockedBuckets = [][]byte{
 type Store struct {
 	db                  *bolt.DB
 	databasePath        string
-	blockCache          *ristretto.Cache
-	validatorEntryCache *ristretto.Cache
+	blockCache          *ristretto.Cache[string, interfaces.ReadOnlySignedBeaconBlock]
+	validatorEntryCache *ristretto.Cache[[]byte, *ethpb.Validator]
 	stateSummaryCache   *stateSummaryCache
 	ctx                 context.Context
 }
@@ -156,7 +158,7 @@ func NewKVStore(ctx context.Context, dirPath string, opts ...KVStoreOption) (*St
 		return nil, err
 	}
 	boltDB.AllocSize = boltAllocSize
-	blockCache, err := ristretto.NewCache(&ristretto.Config{
+	blockCache, err := ristretto.NewCache(&ristretto.Config[string, interfaces.ReadOnlySignedBeaconBlock]{
 		NumCounters: 1000,           // number of keys to track frequency of (1000).
 		MaxCost:     BlockCacheSize, // maximum cost of cache (1000 Blocks).
 		BufferItems: 64,             // number of keys per Get buffer.
@@ -165,7 +167,7 @@ func NewKVStore(ctx context.Context, dirPath string, opts ...KVStoreOption) (*St
 		return nil, err
 	}
 
-	validatorCache, err := ristretto.NewCache(&ristretto.Config{
+	validatorCache, err := ristretto.NewCache(&ristretto.Config[[]byte, *ethpb.Validator]{
 		NumCounters: NumOfValidatorEntries, // number of entries in cache (2 Million).
 		MaxCost:     ValidatorEntryMaxCost, // maximum size of the cache (64Mb)
 		BufferItems: 64,                    // number of keys per Get buffer.

beacon-chain/db/kv/state.go

@@ -744,14 +744,9 @@ func (s *Store) validatorEntries(ctx context.Context, blockRoot [32]byte) ([]*et
 			// get the entry bytes from the cache or from the DB.
 			v, ok := s.validatorEntryCache.Get(key)
 			if ok {
-				valEntry, vType := v.(*ethpb.Validator)
-				if vType {
-					validatorEntries = append(validatorEntries, valEntry)
-					validatorEntryCacheHit.Inc()
-				} else {
-					// this should never happen, but anyway it's good to bail out if one happens.
-					return errors.New("validator cache does not have proper object type")
-				}
+				valEntry := v
+				validatorEntries = append(validatorEntries, valEntry)
+				validatorEntryCacheHit.Inc()
 			} else {
 				// not in cache, so get it from the DB, decode it and add to the entry list.
 				valEntryBytes := valBkt.Get(key)

beacon-chain/db/kv/state_test.go

@@ -321,15 +321,11 @@ func TestState_CanSaveRetrieveValidatorEntriesFromCache(t *testing.T) {
 		hash, hashErr := stateValidators[i].HashTreeRoot()
 		assert.NoError(t, hashErr)
 
-		data, ok := db.validatorEntryCache.Get(string(hash[:]))
+		data, ok := db.validatorEntryCache.Get(hash[:])
 		assert.Equal(t, true, ok)
 		require.NotNil(t, data)
 
-		valEntry, vType := data.(*ethpb.Validator)
-		assert.Equal(t, true, vType)
-		require.NotNil(t, valEntry)
-
-		require.DeepSSZEqual(t, stateValidators[i], valEntry, "validator entry is not matching")
+		require.DeepSSZEqual(t, stateValidators[i], data, "validator entry is not matching")
 	}
 
 	// check if all the validator entries are still intact in the validator entry bucket.
@@ -447,7 +443,7 @@ func TestState_DeleteState(t *testing.T) {
 		assert.NoError(t, hashErr)
 		v, found := db.validatorEntryCache.Get(hash[:])
 		require.Equal(t, false, found)
-		require.Equal(t, nil, v)
+		require.IsNil(t, v)
 	}
 
 	// check if the index of the first state is deleted.

beacon-chain/node/node.go

@@ -865,6 +865,7 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithVerifierWaiter(b.verifyInitWaiter),
 		regularsync.WithAvailableBlocker(bFillStore),
 		regularsync.WithSlasherEnabled(b.slasherEnabled),
+		regularsync.WithLightClientStore(b.lcStore),
 	)
 	return b.services.RegisterService(rs)
 }
@@ -1031,6 +1032,7 @@ func (b *BeaconNode) registerPrometheusService(_ *cli.Context) error {
 	}
 
 	service := prometheus.NewService(
+		b.cliCtx.Context,
 		fmt.Sprintf("%s:%d", b.cliCtx.String(cmd.MonitoringHostFlag.Name), b.cliCtx.Int(flags.MonitoringPortFlag.Name)),
 		b.services,
 		additionalHandlers...,

beacon-chain/p2p/broadcaster.go

@@ -285,13 +285,13 @@ func (s *Service) BroadcastLightClientOptimisticUpdate(ctx context.Context, upda
 		return err
 	}
 
-	// TODO: should we check if the update is too early or too late to broadcast?
-
 	if err := s.broadcastObject(ctx, update, lcOptimisticToTopic(forkDigest)); err != nil {
+		log.WithError(err).Debug("Failed to broadcast light client optimistic update")
 		err := errors.Wrap(err, "could not publish message")
 		tracing.AnnotateError(span, err)
 		return err
 	}
+	log.Debug("Successfully broadcast light client optimistic update")
 
 	return nil
 }
@@ -311,13 +311,13 @@ func (s *Service) BroadcastLightClientFinalityUpdate(ctx context.Context, update
 		return err
 	}
 
-	// TODO: should we check if the update is too early or too late to broadcast?
-
 	if err := s.broadcastObject(ctx, update, lcFinalityToTopic(forkDigest)); err != nil {
+		log.WithError(err).Debug("Failed to broadcast light client finality update")
 		err := errors.Wrap(err, "could not publish message")
 		tracing.AnnotateError(span, err)
 		return err
 	}
+	log.Debug("Successfully broadcast light client finality update")
 
 	return nil
 }

beacon-chain/p2p/gossip_scoring_params.go

@@ -44,6 +44,12 @@ const (
 	// blsToExecutionChangeWeight specifies the scoring weight that we apply to
 	// our bls to execution topic.
 	blsToExecutionChangeWeight = 0.05
+	// lightClientOptimisticUpdateWeight specifies the scoring weight that we apply to
+	// our light client optimistic update topic.
+	lightClientOptimisticUpdateWeight = 0.05
+	// lightClientFinalityUpdateWeight specifies the scoring weight that we apply to
+	// our light client finality update topic.
+	lightClientFinalityUpdateWeight = 0.05
 
 	// maxInMeshScore describes the max score a peer can attain from being in the mesh.
 	maxInMeshScore = 10
@@ -124,6 +130,10 @@ func (s *Service) topicScoreParams(topic string) (*pubsub.TopicScoreParams, erro
 	case strings.Contains(topic, GossipBlobSidecarMessage):
 		// TODO(Deneb): Using the default block scoring. But this should be updated.
 		return defaultBlockTopicParams(), nil
+	case strings.Contains(topic, GossipLightClientOptimisticUpdateMessage):
+		return defaultLightClientOptimisticUpdateTopicParams(), nil
+	case strings.Contains(topic, GossipLightClientFinalityUpdateMessage):
+		return defaultLightClientFinalityUpdateTopicParams(), nil
 	default:
 		return nil, errors.Errorf("unrecognized topic provided for parameter registration: %s", topic)
 	}
@@ -503,6 +513,50 @@ func defaultBlsToExecutionChangeTopicParams() *pubsub.TopicScoreParams {
 	}
 }
 
+func defaultLightClientOptimisticUpdateTopicParams() *pubsub.TopicScoreParams {
+	return &pubsub.TopicScoreParams{
+		TopicWeight:                     lightClientOptimisticUpdateWeight,
+		TimeInMeshWeight:                maxInMeshScore / inMeshCap(),
+		TimeInMeshQuantum:               inMeshTime(),
+		TimeInMeshCap:                   inMeshCap(),
+		FirstMessageDeliveriesWeight:    2,
+		FirstMessageDeliveriesDecay:     scoreDecay(oneHundredEpochs),
+		FirstMessageDeliveriesCap:       5,
+		MeshMessageDeliveriesWeight:     0,
+		MeshMessageDeliveriesDecay:      0,
+		MeshMessageDeliveriesCap:        0,
+		MeshMessageDeliveriesThreshold:  0,
+		MeshMessageDeliveriesWindow:     0,
+		MeshMessageDeliveriesActivation: 0,
+		MeshFailurePenaltyWeight:        0,
+		MeshFailurePenaltyDecay:         0,
+		InvalidMessageDeliveriesWeight:  -2000,
+		InvalidMessageDeliveriesDecay:   scoreDecay(invalidDecayPeriod),
+	}
+}
+
+func defaultLightClientFinalityUpdateTopicParams() *pubsub.TopicScoreParams {
+	return &pubsub.TopicScoreParams{
+		TopicWeight:                     lightClientFinalityUpdateWeight,
+		TimeInMeshWeight:                maxInMeshScore / inMeshCap(),
+		TimeInMeshQuantum:               inMeshTime(),
+		TimeInMeshCap:                   inMeshCap(),
+		FirstMessageDeliveriesWeight:    2,
+		FirstMessageDeliveriesDecay:     scoreDecay(oneHundredEpochs),
+		FirstMessageDeliveriesCap:       5,
+		MeshMessageDeliveriesWeight:     0,
+		MeshMessageDeliveriesDecay:      0,
+		MeshMessageDeliveriesCap:        0,
+		MeshMessageDeliveriesThreshold:  0,
+		MeshMessageDeliveriesWindow:     0,
+		MeshMessageDeliveriesActivation: 0,
+		MeshFailurePenaltyWeight:        0,
+		MeshFailurePenaltyDecay:         0,
+		InvalidMessageDeliveriesWeight:  -2000,
+		InvalidMessageDeliveriesDecay:   scoreDecay(invalidDecayPeriod),
+	}
+}
+
 func oneSlotDuration() time.Duration {
 	return time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
 }

beacon-chain/p2p/gossip_scoring_params_test.go

@@ -75,4 +75,6 @@ func TestLoggingParameters(_ *testing.T) {
 	logGossipParameters("testing", defaultAttesterSlashingTopicParams())
 	logGossipParameters("testing", defaultProposerSlashingTopicParams())
 	logGossipParameters("testing", defaultVoluntaryExitTopicParams())
+	logGossipParameters("testing", defaultLightClientOptimisticUpdateTopicParams())
+	logGossipParameters("testing", defaultLightClientFinalityUpdateTopicParams())
 }

beacon-chain/p2p/gossip_topic_mappings_test.go

@@ -73,6 +73,12 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	pMessage = GossipTopicMappings(AggregateAndProofSubnetTopicFormat, altairForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedAggregateAttestationAndProof)
 	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientOptimisticUpdateTopicFormat, altairForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientOptimisticUpdateAltair)
+	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientFinalityUpdateTopicFormat, altairForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientFinalityUpdateAltair)
+	assert.Equal(t, true, ok)
 
 	// Bellatrix Fork
 	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, bellatrixForkEpoch)
@@ -87,6 +93,12 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	pMessage = GossipTopicMappings(AggregateAndProofSubnetTopicFormat, bellatrixForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedAggregateAttestationAndProof)
 	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientOptimisticUpdateTopicFormat, bellatrixForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientOptimisticUpdateAltair)
+	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientFinalityUpdateTopicFormat, bellatrixForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientFinalityUpdateAltair)
+	assert.Equal(t, true, ok)
 
 	// Capella Fork
 	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, capellaForkEpoch)
@@ -101,6 +113,12 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	pMessage = GossipTopicMappings(AggregateAndProofSubnetTopicFormat, capellaForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedAggregateAttestationAndProof)
 	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientOptimisticUpdateTopicFormat, capellaForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientOptimisticUpdateCapella)
+	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientFinalityUpdateTopicFormat, capellaForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientFinalityUpdateCapella)
+	assert.Equal(t, true, ok)
 
 	// Deneb Fork
 	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, denebForkEpoch)
@@ -115,6 +133,12 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	pMessage = GossipTopicMappings(AggregateAndProofSubnetTopicFormat, denebForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedAggregateAttestationAndProof)
 	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientOptimisticUpdateTopicFormat, denebForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientOptimisticUpdateDeneb)
+	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientFinalityUpdateTopicFormat, denebForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientFinalityUpdateDeneb)
+	assert.Equal(t, true, ok)
 
 	// Electra Fork
 	pMessage = GossipTopicMappings(BlockSubnetTopicFormat, electraForkEpoch)
@@ -129,4 +153,10 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	pMessage = GossipTopicMappings(AggregateAndProofSubnetTopicFormat, electraForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedAggregateAttestationAndProofElectra)
 	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientOptimisticUpdateTopicFormat, electraForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientOptimisticUpdateDeneb)
+	assert.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(LightClientFinalityUpdateTopicFormat, electraForkEpoch)
+	_, ok = pMessage.(*ethpb.LightClientFinalityUpdateElectra)
+	assert.Equal(t, true, ok)
 }

beacon-chain/p2p/interfaces.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
 	"github.com/ethereum/go-ethereum/p2p/enr"
@@ -36,6 +37,8 @@ type Broadcaster interface {
 	BroadcastAttestation(ctx context.Context, subnet uint64, att ethpb.Att) error
 	BroadcastSyncCommitteeMessage(ctx context.Context, subnet uint64, sMsg *ethpb.SyncCommitteeMessage) error
 	BroadcastBlob(ctx context.Context, subnet uint64, blob *ethpb.BlobSidecar) error
+	BroadcastLightClientOptimisticUpdate(ctx context.Context, update interfaces.LightClientOptimisticUpdate) error
+	BroadcastLightClientFinalityUpdate(ctx context.Context, update interfaces.LightClientFinalityUpdate) error
 }
 
 // SetStreamHandler configures p2p to handle streams of a certain topic ID.

beacon-chain/p2p/testing/BUILD.bazel

@@ -20,6 +20,7 @@ go_library(
         "//beacon-chain/p2p/encoder:go_default_library",
         "//beacon-chain/p2p/peers:go_default_library",
         "//beacon-chain/p2p/peers/scorers:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/metadata:go_default_library",
         "//testing/require:go_default_library",

beacon-chain/p2p/testing/fuzz_p2p.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
 	"github.com/ethereum/go-ethereum/p2p/enr"
@@ -148,6 +149,16 @@ func (*FakeP2P) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.BlobSidecar)
 	return nil
 }
 
+// BroadcastLightClientOptimisticUpdate -- fake.
+func (*FakeP2P) BroadcastLightClientOptimisticUpdate(_ context.Context, _ interfaces.LightClientOptimisticUpdate) error {
+	return nil
+}
+
+// BroadcastLightClientFinalityUpdate -- fake.
+func (*FakeP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfaces.LightClientFinalityUpdate) error {
+	return nil
+}
+
 // InterceptPeerDial -- fake.
 func (*FakeP2P) InterceptPeerDial(peer.ID) (allow bool) {
 	return true

beacon-chain/p2p/testing/mock_broadcaster.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"sync/atomic"
 
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"google.golang.org/protobuf/proto"
 )
@@ -48,6 +49,18 @@ func (m *MockBroadcaster) BroadcastBlob(context.Context, uint64, *ethpb.BlobSide
 	return nil
 }
 
+// BroadcastLightClientOptimisticUpdate records a broadcast occurred.
+func (m *MockBroadcaster) BroadcastLightClientOptimisticUpdate(_ context.Context, _ interfaces.LightClientOptimisticUpdate) error {
+	m.BroadcastCalled.Store(true)
+	return nil
+}
+
+// BroadcastLightClientFinalityUpdate records a broadcast occurred.
+func (m *MockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfaces.LightClientFinalityUpdate) error {
+	m.BroadcastCalled.Store(true)
+	return nil
+}
+
 // NumMessages returns the number of messages broadcasted.
 func (m *MockBroadcaster) NumMessages() int {
 	m.msgLock.Lock()

beacon-chain/p2p/testing/p2p.go

@@ -13,6 +13,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -207,6 +208,18 @@ func (p *TestP2P) BroadcastBlob(context.Context, uint64, *ethpb.BlobSidecar) err
 	return nil
 }
 
+// BroadcastLightClientOptimisticUpdate broadcasts an optimistic update for mock.
+func (p *TestP2P) BroadcastLightClientOptimisticUpdate(_ context.Context, _ interfaces.LightClientOptimisticUpdate) error {
+	p.BroadcastCalled.Store(true)
+	return nil
+}
+
+// BroadcastLightClientFinalityUpdate broadcasts a finality update for mock.
+func (p *TestP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfaces.LightClientFinalityUpdate) error {
+	p.BroadcastCalled.Store(true)
+	return nil
+}
+
 // SetStreamHandler for RPC.
 func (p *TestP2P) SetStreamHandler(topic string, handler network.StreamHandler) {
 	p.BHost.SetStreamHandler(protocol.ID(topic), handler)

beacon-chain/p2p/types/BUILD.bazel

@@ -21,6 +21,7 @@ go_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",
         "//consensus-types/wrapper:go_default_library",
         "//encoding/bytesutil:go_default_library",

beacon-chain/p2p/types/object_mapping.go

@@ -4,6 +4,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	lightclientConsensusTypes "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -36,6 +37,12 @@ var (
 	// AttesterSlashingMap maps the fork-version to the underlying data type for that particular
 	// fork period.
 	AttesterSlashingMap map[[4]byte]func() (ethpb.AttSlashing, error)
+	// LightClientOptimisticUpdateMap maps the fork-version to the underlying data type for that
+	// particular fork period.
+	LightClientOptimisticUpdateMap map[[4]byte]func() (interfaces.LightClientOptimisticUpdate, error)
+	// LightClientFinalityUpdateMap maps the fork-version to the underlying data type for that
+	// particular fork period.
+	LightClientFinalityUpdateMap map[[4]byte]func() (interfaces.LightClientFinalityUpdate, error)
 )
 
 // InitializeDataMaps initializes all the relevant object maps. This function is called to
@@ -179,4 +186,42 @@ func InitializeDataMaps() {
 			return &ethpb.AttesterSlashingElectra{}, nil
 		},
 	}
+
+	// Reset our light client optimistic update map.
+	LightClientOptimisticUpdateMap = map[[4]byte]func() (interfaces.LightClientOptimisticUpdate, error){
+		bytesutil.ToBytes4(params.BeaconConfig().AltairForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyOptimisticUpdateAltair(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().BellatrixForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyOptimisticUpdateAltair(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().CapellaForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyOptimisticUpdateCapella(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().DenebForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyOptimisticUpdateDeneb(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().ElectraForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyOptimisticUpdateDeneb(), nil
+		},
+	}
+
+	// Reset our light client finality update map.
+	LightClientFinalityUpdateMap = map[[4]byte]func() (interfaces.LightClientFinalityUpdate, error){
+		bytesutil.ToBytes4(params.BeaconConfig().AltairForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyFinalityUpdateAltair(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().BellatrixForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyFinalityUpdateAltair(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().CapellaForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyFinalityUpdateCapella(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().DenebForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyFinalityUpdateDeneb(), nil
+		},
+		bytesutil.ToBytes4(params.BeaconConfig().ElectraForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyFinalityUpdateElectra(), nil
+		},
+	}
 }

beacon-chain/p2p/utils.go

@@ -77,8 +77,9 @@ func privKey(cfg *Config) (*ecdsa.PrivateKey, error) {
 		return nil, err
 	}
 
-	// If the StaticPeerID flag is not set and if peerDAS is not enabled, return the private key.
-	if !(cfg.StaticPeerID || params.PeerDASEnabled()) {
+	// If the StaticPeerID flag is not set or the Fulu epoch is not set, return the private key.
+	// Starting at Fulu, we don't want to generate a new key every time, to avoid custody columns changes.
+	if !(cfg.StaticPeerID || params.FuluEnabled()) {
 		return ecdsaprysm.ConvertFromInterfacePrivKey(priv)
 	}
 

beacon-chain/rpc/BUILD.bazel

@@ -66,7 +66,7 @@ go_library(
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promhttp:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//plugin/ocgrpc:go_default_library",
+        "@io_opentelemetry_go_contrib_instrumentation_google_golang_org_grpc_otelgrpc//:go_default_library",
         "@org_golang_google_grpc//:go_default_library",
         "@org_golang_google_grpc//credentials:go_default_library",
         "@org_golang_google_grpc//peer:go_default_library",

beacon-chain/rpc/endpoints.go

@@ -894,6 +894,15 @@ func (s *Service) beaconEndpoints(
 			handler: server.GetPendingDeposits,
 			methods: []string{http.MethodGet},
 		},
+		{
+			template: "/eth/v1/beacon/states/{state_id}/pending_consolidations",
+			name:     namespace + ".GetPendingConsolidations",
+			middleware: []middleware.Middleware{
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType}),
+			},
+			handler: server.GetPendingDeposits,
+			methods: []string{http.MethodGet},
+		},
 		{
 			template: "/eth/v1/beacon/states/{state_id}/pending_partial_withdrawals",
 			name:     namespace + ".GetPendingPartialWithdrawals",
@@ -1041,6 +1050,7 @@ func (s *Service) eventsEndpoints() []endpoint {
 		HeadFetcher:            s.cfg.HeadFetcher,
 		ChainInfoFetcher:       s.cfg.ChainInfoFetcher,
 		TrackedValidatorsCache: s.cfg.TrackedValidatorsCache,
+		StateGen:               s.cfg.StateGen,
 	}
 
 	const namespace = "events"

beacon-chain/rpc/endpoints_test.go

@@ -30,6 +30,7 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v1/beacon/states/{state_id}/randao":                      {http.MethodGet},
 		"/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/headers":                                       {http.MethodGet},
 		"/eth/v1/beacon/headers/{block_id}":                            {http.MethodGet},
 		"/eth/v1/beacon/blinded_blocks":                                {http.MethodPost},

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

@@ -1613,6 +1613,62 @@ func (s *Server) broadcastSeenBlockSidecars(
 	return nil
 }
 
+// GetPendingConsolidations returns pending deposits for state with given 'stateId'.
+// Should return 400 if the state retrieved is prior to Electra.
+// Supports both JSON and SSZ responses based on Accept header.
+func (s *Server) GetPendingConsolidations(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.GetPendingDeposits")
+	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.Electra {
+		httputil.HandleError(w, "state_id is prior to electra", http.StatusBadRequest)
+		return
+	}
+	pd, err := st.PendingConsolidations()
+	if err != nil {
+		httputil.HandleError(w, "Could not get pending consolidations: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set(api.VersionHeader, version.String(st.Version()))
+	if httputil.RespondWithSsz(r) {
+		sszData, err := serializeItems(pd)
+		if err != nil {
+			httputil.HandleError(w, "Failed to serialize pending consolidations: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		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)
+		resp := structs.GetPendingConsolidationsResponse{
+			Version:             version.String(st.Version()),
+			ExecutionOptimistic: isOptimistic,
+			Finalized:           isFinalized,
+			Data:                structs.PendingConsolidationsFromConsensus(pd),
+		}
+		httputil.WriteJson(w, resp)
+	}
+}
+
 // GetPendingDeposits returns pending deposits for state with given 'stateId'.
 // Should return 400 if the state retrieved is prior to Electra.
 // Supports both JSON and SSZ responses based on Accept header.

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

@@ -4755,6 +4755,191 @@ func Test_validateBlobSidecars(t *testing.T) {
 	require.ErrorContains(t, "could not verify blob proof: can't verify opening proof", s.validateBlobSidecars(b, [][]byte{blob[:]}, [][]byte{proof[:]}))
 }
 
+func TestGetPendingConsolidations(t *testing.T) {
+	st, _ := util.DeterministicGenesisStateElectra(t, 10)
+
+	cs := make([]*eth.PendingConsolidation, 10)
+	for i := 0; i < len(cs); i += 1 {
+		cs[i] = &eth.PendingConsolidation{
+			SourceIndex: primitives.ValidatorIndex(i),
+			TargetIndex: primitives.ValidatorIndex(i + 1),
+		}
+	}
+	require.NoError(t, st.SetPendingConsolidations(cs))
+
+	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}/pending_consolidations", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetPendingConsolidations(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+		require.Equal(t, "electra", rec.Header().Get(api.VersionHeader))
+
+		var resp structs.GetPendingConsolidationsResponse
+		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)
+
+		expectedConsolidations := structs.PendingConsolidationsFromConsensus(cs)
+		require.DeepEqual(t, expectedConsolidations, resp.Data)
+	})
+	t.Run("ssz response", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/pending_consolidations", nil)
+		req.Header.Set("Accept", "application/octet-stream")
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetPendingConsolidations(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+		require.Equal(t, "electra", rec.Header().Get(api.VersionHeader))
+
+		responseBytes := rec.Body.Bytes()
+		var recoveredConsolidations []*eth.PendingConsolidation
+
+		// Verify total size matches expected number of deposits
+		consolidationSize := (&eth.PendingConsolidation{}).SizeSSZ()
+		require.Equal(t, len(responseBytes), consolidationSize*len(cs))
+
+		for i := 0; i < len(cs); i++ {
+			start := i * consolidationSize
+			end := start + consolidationSize
+
+			var c eth.PendingConsolidation
+			require.NoError(t, c.UnmarshalSSZ(responseBytes[start:end]))
+			recoveredConsolidations = append(recoveredConsolidations, &c)
+		}
+		require.DeepEqual(t, cs, recoveredConsolidations)
+	})
+	t.Run("pre electra state", func(t *testing.T) {
+		preElectraSt, _ := util.DeterministicGenesisStateDeneb(t, 1)
+		preElectraServer := &Server{
+			Stater: &testutil.MockStater{
+				BeaconState: preElectraSt,
+			},
+			OptimisticModeFetcher: chainService,
+			FinalizationFetcher:   chainService,
+		}
+
+		// Test JSON request
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/pending_consolidations", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		preElectraServer.GetPendingConsolidations(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 electra", errResp.Message)
+
+		// Test SSZ request
+		sszReq := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/pending_consolidations", nil)
+		sszReq.Header.Set("Accept", "application/octet-stream")
+		sszReq.SetPathValue("state_id", "head")
+		sszRec := httptest.NewRecorder()
+		sszRec.Body = new(bytes.Buffer)
+
+		preElectraServer.GetPendingConsolidations(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 electra", 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}/pending_consolidations", nil)
+		// Intentionally not setting state_id
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetPendingConsolidations(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}/pending_consolidations", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		optimisticServer.GetPendingConsolidations(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+
+		var resp structs.GetPendingConsolidationsResponse
+		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}/pending_consolidations", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		finalizedServer.GetPendingConsolidations(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+
+		var resp structs.GetPendingConsolidationsResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+		require.Equal(t, true, resp.Finalized)
+	})
+}
+
 func TestGetPendingDeposits(t *testing.T) {
 	st, _ := util.DeterministicGenesisStateElectra(t, 10)
 

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

@@ -200,7 +200,7 @@ func TestGetSpec(t *testing.T) {
 	data, ok := resp.Data.(map[string]interface{})
 	require.Equal(t, true, ok)
 
-	assert.Equal(t, 169, len(data))
+	assert.Equal(t, 175, len(data))
 	for k, v := range data {
 		t.Run(k, func(t *testing.T) {
 			switch k {
@@ -545,6 +545,18 @@ func TestGetSpec(t *testing.T) {
 				assert.Equal(t, "9", v)
 			case "MAX_REQUEST_BLOB_SIDECARS_ELECTRA":
 				assert.Equal(t, "1152", v)
+			case "NUMBER_OF_CUSTODY_GROUPS":
+				assert.Equal(t, "128", v)
+			case "BALANCE_PER_ADDITIONAL_CUSTODY_GROUP":
+				assert.Equal(t, "32000000000", v)
+			case "CUSTODY_REQUIREMENT":
+				assert.Equal(t, "4", v)
+			case "SAMPLES_PER_SLOT":
+				assert.Equal(t, "8", v)
+			case "VALIDATOR_CUSTODY_REQUIREMENT":
+				assert.Equal(t, "8", v)
+			case "MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS":
+				assert.Equal(t, "4096", v)
 			case "MAX_BLOB_COMMITMENTS_PER_BLOCK":
 				assert.Equal(t, "95", v)
 			case "MAX_BYTES_PER_TRANSACTION":
@@ -559,6 +571,8 @@ func TestGetSpec(t *testing.T) {
 				assert.Equal(t, "100", v)
 			case "KZG_COMMITMENT_INCLUSION_PROOF_DEPTH":
 				assert.Equal(t, "101", v)
+			case "MAX_BLOBS_PER_BLOCK_FULU":
+				assert.Equal(t, "12", v)
 			case "BLOB_SIDECAR_SUBNET_COUNT":
 				assert.Equal(t, "102", v)
 			case "BLOB_SIDECAR_SUBNET_COUNT_ELECTRA":

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

@@ -20,6 +20,7 @@ go_library(
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/state:go_default_library",
+        "//beacon-chain/state/stategen:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/payload-attribute:go_default_library",
@@ -53,6 +54,7 @@ go_test(
         "//beacon-chain/core/feed/operation:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/state:go_default_library",
+        "//beacon-chain/state/stategen/mock:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

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

@@ -37,7 +37,6 @@ import (
 )
 
 const DefaultEventFeedDepth = 1000
-const payloadAttributeTimeout = 2 * time.Second
 
 const (
 	InvalidTopic = "__invalid__"
@@ -627,6 +626,7 @@ func (s *Server) lazyReaderForEvent(ctx context.Context, event *feed.Event, topi
 }
 
 var errUnsupportedPayloadAttribute = errors.New("cannot compute payload attributes pre-Bellatrix")
+var errPayloadAttributeExpired = errors.New("skipping payload attribute event for past slot")
 
 func (s *Server) computePayloadAttributes(ctx context.Context, st state.ReadOnlyBeaconState, root [32]byte, proposer primitives.ValidatorIndex, timestamp uint64, randao []byte) (payloadattribute.Attributer, error) {
 	v := st.Version()
@@ -681,48 +681,48 @@ var zeroRoot [32]byte
 // needsFill allows tests to provide filled EventData values. An ordinary event data value fired by the blockchain package will have
 // all of the checked fields empty, so the logical short circuit should hit immediately.
 func needsFill(ev payloadattribute.EventData) bool {
-	return ev.HeadState == nil || ev.HeadState.IsNil() || ev.HeadState.LatestBlockHeader() == nil ||
-		ev.HeadBlock == nil || ev.HeadBlock.IsNil() ||
-		ev.HeadRoot == zeroRoot || len(ev.ParentBlockRoot) == 0 || len(ev.ParentBlockHash) == 0 ||
+	return len(ev.ParentBlockHash) == 0 ||
 		ev.Attributer == nil || ev.Attributer.IsEmpty()
 }
 
 func (s *Server) fillEventData(ctx context.Context, ev payloadattribute.EventData) (payloadattribute.EventData, error) {
-	var err error
-
 	if !needsFill(ev) {
 		return ev, nil
 	}
-
-	ev.HeadState, err = s.HeadFetcher.HeadState(ctx)
-	if err != nil {
-		return ev, errors.Wrap(err, "could not get head state")
+	if ev.HeadBlock == nil || ev.HeadBlock.IsNil() {
+		return ev, errors.New("head block is nil")
+	}
+	if ev.HeadRoot == zeroRoot {
+		return ev, errors.New("head root is empty")
 	}
 
-	ev.HeadBlock, err = s.HeadFetcher.HeadBlock(ctx)
-	if err != nil {
-		return ev, errors.Wrap(err, "could not look up head block")
-	}
-	ev.HeadRoot, err = ev.HeadBlock.Block().HashTreeRoot()
-	if err != nil {
-		return ev, errors.Wrap(err, "could not compute head block root")
-	}
-	pr := ev.HeadBlock.Block().ParentRoot()
-	ev.ParentBlockRoot = pr[:]
-
-	hsr, err := ev.HeadState.LatestBlockHeader().HashTreeRoot()
-	if err != nil {
-		return ev, errors.Wrap(err, "could not compute latest block header root")
-	}
+	var err error
+	var st state.BeaconState
 
+	// If head is in the same block as the proposal slot, we can use the "read only" state cache.
 	pse := slots.ToEpoch(ev.ProposalSlot)
-	st := ev.HeadState
-	if slots.ToEpoch(st.Slot()) != pse {
-		st, err = transition.ProcessSlotsUsingNextSlotCache(ctx, st, hsr[:], ev.ProposalSlot)
+	if slots.ToEpoch(ev.HeadBlock.Block().Slot()) == pse {
+		st = s.StateGen.StateByRootIfCachedNoCopy(ev.HeadRoot)
+	}
+	// If st is nil, we couldn't get the state from the cache, or it isn't in the same epoch.
+	if st == nil || st.IsNil() {
+		st, err = s.StateGen.StateByRoot(ctx, ev.HeadRoot)
 		if err != nil {
-			return ev, errors.Wrap(err, "could not run process blocks on head state into the proposal slot epoch")
+			return ev, errors.Wrap(err, "could not get head state")
+		}
+		// double check that we need to process_slots, just in case we got here via a hot state cache miss.
+		if slots.ToEpoch(st.Slot()) < pse {
+			start, err := slots.EpochStart(pse)
+			if err != nil {
+				return ev, errors.Wrap(err, "invalid state slot; could not compute epoch start")
+			}
+			st, err = transition.ProcessSlotsUsingNextSlotCache(ctx, st, ev.HeadRoot[:], start)
+			if err != nil {
+				return ev, errors.Wrap(err, "could not run process blocks on head state into the proposal slot epoch")
+			}
 		}
 	}
+
 	ev.ProposerIndex, err = helpers.BeaconProposerIndexAtSlot(ctx, st, ev.ProposalSlot)
 	if err != nil {
 		return ev, errors.Wrap(err, "failed to compute proposer index")
@@ -743,14 +743,18 @@ func (s *Server) fillEventData(ctx context.Context, ev payloadattribute.EventDat
 	if err != nil {
 		return ev, errors.Wrap(err, "could not get head state slot time")
 	}
-	ev.Attributer, err = s.computePayloadAttributes(ctx, st, hsr, ev.ProposerIndex, uint64(t.Unix()), randao)
+	ev.Attributer, err = s.computePayloadAttributes(ctx, st, ev.HeadRoot, ev.ProposerIndex, uint64(t.Unix()), randao)
 	return ev, err
 }
 
 // This event stream is intended to be used by builders and relays.
 // Parent fields are based on state at N_{current_slot}, while the rest of fields are based on state of N_{current_slot + 1}
 func (s *Server) payloadAttributesReader(ctx context.Context, ev payloadattribute.EventData) (lazyReader, error) {
-	ctx, cancel := context.WithTimeout(ctx, payloadAttributeTimeout)
+	deadline := slots.BeginsAt(ev.ProposalSlot, s.ChainInfoFetcher.GenesisTime())
+	if deadline.Before(time.Now()) {
+		return nil, errors.Wrapf(errPayloadAttributeExpired, "proposal slot time %d", deadline.Unix())
+	}
+	ctx, cancel := context.WithDeadline(ctx, deadline)
 	edc := make(chan asyncPayloadAttrData)
 	go func() {
 		d := asyncPayloadAttrData{}
@@ -772,7 +776,7 @@ func (s *Server) payloadAttributesReader(ctx context.Context, ev payloadattribut
 			ProposerIndex:     strconv.FormatUint(uint64(ev.ProposerIndex), 10),
 			ProposalSlot:      strconv.FormatUint(uint64(ev.ProposalSlot), 10),
 			ParentBlockNumber: strconv.FormatUint(ev.ParentBlockNumber, 10),
-			ParentBlockRoot:   hexutil.Encode(ev.ParentBlockRoot),
+			ParentBlockRoot:   hexutil.Encode(ev.HeadRoot[:]),
 			ParentBlockHash:   hexutil.Encode(ev.ParentBlockHash),
 			PayloadAttributes: attributesBytes,
 		})

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

@@ -18,6 +18,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/operation"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen/mock"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -522,15 +523,22 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 				// to avoid slot processing
 				require.NoError(t, st.SetSlot(currentSlot+1))
 				b := tc.getBlock()
+				genesis := time.Now()
+				require.NoError(t, st.SetGenesisTime(uint64(genesis.Unix())))
 				mockChainService := &mockChain.ChainService{
-					Root:  make([]byte, 32),
-					State: st,
-					Block: b,
-					Slot:  &currentSlot,
+					Root:    make([]byte, 32),
+					State:   st,
+					Block:   b,
+					Slot:    &currentSlot,
+					Genesis: genesis,
 				}
+				headRoot, err := b.Block().HashTreeRoot()
+				require.NoError(t, err)
 
 				stn := mockChain.NewEventFeedWrapper()
 				opn := mockChain.NewEventFeedWrapper()
+				stategen := mock.NewService()
+				stategen.AddStateForRoot(st, headRoot)
 				s := &Server{
 					StateNotifier:          &mockChain.SimpleNotifier{Feed: stn},
 					OperationNotifier:      &mockChain.SimpleNotifier{Feed: opn},
@@ -538,6 +546,7 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 					ChainInfoFetcher:       mockChainService,
 					TrackedValidatorsCache: cache.NewTrackedValidatorsCache(),
 					EventWriteTimeout:      testEventWriteTimeout,
+					StateGen:               stategen,
 				}
 				if tc.SetTrackedValidatorsCache != nil {
 					tc.SetTrackedValidatorsCache(s.TrackedValidatorsCache)
@@ -551,13 +560,11 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 						Type: statefeed.PayloadAttributes,
 						Data: payloadattribute.EventData{
 							ProposerIndex:     0,
-							ProposalSlot:      0,
+							ProposalSlot:      mockChainService.CurrentSlot() + 1,
 							ParentBlockNumber: 0,
-							ParentBlockRoot:   make([]byte, 32),
 							ParentBlockHash:   make([]byte, 32),
-							HeadState:         st,
 							HeadBlock:         b,
-							HeadRoot:          [fieldparams.RootLength]byte{},
+							HeadRoot:          headRoot,
 						},
 					},
 				}
@@ -575,8 +582,6 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 func TestFillEventData(t *testing.T) {
 	ctx := context.Background()
 	t.Run("AlreadyFilledData_ShouldShortCircuitWithoutError", func(t *testing.T) {
-		st, err := util.NewBeaconStateBellatrix()
-		require.NoError(t, err)
 		b, err := blocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlockBellatrix(&eth.SignedBeaconBlockBellatrix{}))
 		require.NoError(t, err)
 		attributor, err := payloadattribute.New(&enginev1.PayloadAttributes{
@@ -584,11 +589,9 @@ func TestFillEventData(t *testing.T) {
 		})
 		require.NoError(t, err)
 		alreadyFilled := payloadattribute.EventData{
-			HeadState:       st,
 			HeadBlock:       b,
 			HeadRoot:        [32]byte{1, 2, 3},
 			Attributer:      attributor,
-			ParentBlockRoot: []byte{1, 2, 3},
 			ParentBlockHash: []byte{4, 5, 6},
 		}
 		srv := &Server{} // No real HeadFetcher needed here since it won't be called.
@@ -612,12 +615,14 @@ func TestFillEventData(t *testing.T) {
 			Timestamp: uint64(time.Now().Unix()),
 		})
 		require.NoError(t, err)
+		headRoot, err := b.Block().HashTreeRoot()
+		require.NoError(t, err)
 		// Create an event data object missing certain fields:
 		partial := payloadattribute.EventData{
-			// The presence of a nil HeadState, nil HeadBlock, zeroed HeadRoot, etc.
-			// will cause fillEventData to try to fill the values.
 			ProposalSlot: 42,         // different epoch from current slot
 			Attributer:   attributor, // Must be Bellatrix or later
+			HeadBlock:    b,
+			HeadRoot:     headRoot,
 		}
 		currentSlot := primitives.Slot(0)
 		// to avoid slot processing
@@ -629,6 +634,8 @@ func TestFillEventData(t *testing.T) {
 			Slot:  &currentSlot,
 		}
 
+		stategen := mock.NewService()
+		stategen.AddStateForRoot(st, headRoot)
 		stn := mockChain.NewEventFeedWrapper()
 		opn := mockChain.NewEventFeedWrapper()
 		srv := &Server{
@@ -638,16 +645,15 @@ func TestFillEventData(t *testing.T) {
 			ChainInfoFetcher:       mockChainService,
 			TrackedValidatorsCache: cache.NewTrackedValidatorsCache(),
 			EventWriteTimeout:      testEventWriteTimeout,
+			StateGen:               stategen,
 		}
 
 		filled, err := srv.fillEventData(ctx, partial)
 		require.NoError(t, err, "expected successful fill of partial event data")
 
 		// Verify that fields have been updated from the mock data:
-		require.NotNil(t, filled.HeadState, "HeadState should be assigned")
 		require.NotNil(t, filled.HeadBlock, "HeadBlock should be assigned")
 		require.NotEqual(t, [32]byte{}, filled.HeadRoot, "HeadRoot should no longer be zero")
-		require.NotEmpty(t, filled.ParentBlockRoot, "ParentBlockRoot should be filled")
 		require.NotEmpty(t, filled.ParentBlockHash, "ParentBlockHash should be filled")
 		require.Equal(t, uint64(0), filled.ParentBlockNumber, "ParentBlockNumber must match mock block")
 

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

@@ -10,6 +10,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	opfeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/operation"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
 )
 
 // Server defines a server implementation of the http events service,
@@ -23,4 +24,5 @@ type Server struct {
 	KeepAliveInterval      time.Duration
 	EventFeedDepth         int
 	EventWriteTimeout      time.Duration
+	StateGen               stategen.StateManager
 }

beacon-chain/rpc/prysm/v1alpha1/beacon/assignments.go

@@ -18,7 +18,7 @@ import (
 
 const errEpoch = "cannot retrieve information about an epoch in the future, current epoch %d, requesting %d"
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListValidatorAssignments retrieves the validator assignments for a given epoch,
 // optional validator indices or public keys may be included to filter validator assignments.

beacon-chain/rpc/prysm/v1alpha1/beacon/attestations.go

@@ -49,7 +49,7 @@ func mapAttestationsByTargetRoot(atts []ethpb.Att) map[[32]byte][]ethpb.Att {
 	return attsMap
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListAttestations retrieves attestations by block root, slot, or epoch.
 // Attestations are sorted by data slot by default.
@@ -115,7 +115,7 @@ func (bs *Server) ListAttestations(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListAttestationsElectra retrieves attestations by block root, slot, or epoch.
 // Attestations are sorted by data slot by default.
@@ -180,7 +180,7 @@ func (bs *Server) ListAttestationsElectra(ctx context.Context, req *ethpb.ListAt
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListIndexedAttestations retrieves indexed attestations by block root.
 // IndexedAttestationsForEpoch are sorted by data slot by default. Start-end epoch
@@ -242,7 +242,7 @@ func (bs *Server) ListIndexedAttestations(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListIndexedAttestationsElectra retrieves indexed attestations by block root.
 // IndexedAttestationsForEpoch are sorted by data slot by default. Start-end epoch
@@ -305,7 +305,7 @@ func (bs *Server) ListIndexedAttestationsElectra(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // AttestationPool retrieves pending attestations.
 //
@@ -350,7 +350,7 @@ func (bs *Server) AttestationPool(_ context.Context, req *ethpb.AttestationPoolR
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 func (bs *Server) AttestationPoolElectra(_ context.Context, req *ethpb.AttestationPoolRequest) (*ethpb.AttestationPoolElectraResponse, error) {
 	var atts []*ethpb.AttestationElectra
 	var err error

beacon-chain/rpc/prysm/v1alpha1/beacon/blocks.go

@@ -26,7 +26,7 @@ type blockContainer struct {
 	isCanonical bool
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListBeaconBlocks retrieves blocks by root, slot, or epoch.
 //
@@ -246,7 +246,7 @@ func (bs *Server) listBlocksForGenesis(ctx context.Context, _ *ethpb.ListBlocksR
 	}}, 1, strconv.Itoa(0), nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetChainHead retrieves information about the head of the beacon chain from
 // the view of the beacon chain node.

beacon-chain/rpc/prysm/v1alpha1/beacon/committees.go

@@ -15,7 +15,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListBeaconCommittees for a given epoch.
 //

beacon-chain/rpc/prysm/v1alpha1/beacon/config.go

@@ -10,7 +10,7 @@ import (
 	"google.golang.org/protobuf/types/known/emptypb"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetBeaconConfig retrieves the current configuration parameters of the beacon chain.
 func (_ *Server) GetBeaconConfig(_ context.Context, _ *emptypb.Empty) (*ethpb.BeaconConfig, error) {

beacon-chain/rpc/prysm/v1alpha1/beacon/slashings.go

@@ -11,7 +11,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitProposerSlashing receives a proposer slashing object via
 // RPC and injects it into the beacon node's operations pool.
@@ -38,12 +38,12 @@ func (bs *Server) SubmitProposerSlashing(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 func (bs *Server) SubmitAttesterSlashing(ctx context.Context, req *ethpb.AttesterSlashing) (*ethpb.SubmitSlashingResponse, error) {
 	return bs.submitAttesterSlashing(ctx, req)
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitAttesterSlashingElectra receives an attester slashing object via
 // RPC and injects it into the beacon node's operations pool.

beacon-chain/rpc/prysm/v1alpha1/beacon/validators.go

@@ -24,7 +24,7 @@ import (
 	"google.golang.org/protobuf/types/known/emptypb"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListValidatorBalances retrieves the validator balances for a given set of public keys.
 // An optional Epoch parameter is provided to request historical validator balances from
@@ -182,7 +182,7 @@ func (bs *Server) ListValidatorBalances(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListValidators retrieves the current list of active validators with an optional historical epoch flag to
 // retrieve validator set in time.
@@ -342,7 +342,7 @@ func (bs *Server) ListValidators(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetValidator information from any validator in the registry by index or public key.
 func (bs *Server) GetValidator(
@@ -388,7 +388,7 @@ func (bs *Server) GetValidator(
 	return nil, status.Error(codes.NotFound, "No validator matched filter criteria")
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetValidatorActiveSetChanges retrieves the active set changes for a given epoch.
 //
@@ -416,7 +416,7 @@ func (bs *Server) GetValidatorActiveSetChanges(
 	return as, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetValidatorParticipation retrieves the validator participation information for a given epoch,
 // it returns the information about validator's participation rate in voting on the proof of stake
@@ -443,7 +443,7 @@ func (bs *Server) GetValidatorParticipation(
 	return vp, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetValidatorQueue retrieves the current validator queue information.
 func (bs *Server) GetValidatorQueue(
@@ -536,7 +536,7 @@ func (bs *Server) GetValidatorQueue(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetValidatorPerformance reports the validator's latest balance along with other important metrics on
 // rewards and penalties throughout its lifecycle in the beacon chain.
@@ -550,7 +550,7 @@ func (bs *Server) GetValidatorPerformance(
 	return response, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetIndividualVotes retrieves individual voting status of validators.
 func (bs *Server) GetIndividualVotes(

beacon-chain/rpc/prysm/v1alpha1/debug/block.go

@@ -17,7 +17,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetBlock in an ssz-encoded format by block root.
 func (ds *Server) GetBlock(
@@ -41,7 +41,7 @@ func (ds *Server) GetBlock(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetInclusionSlot of an attestation in block.
 func (ds *Server) GetInclusionSlot(ctx context.Context, req *pbrpc.InclusionSlotRequest) (*pbrpc.InclusionSlotResponse, error) {

beacon-chain/rpc/prysm/v1alpha1/debug/p2p.go

@@ -13,7 +13,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetPeer returns the data known about the peer defined by the provided peer id.
 func (ds *Server) GetPeer(_ context.Context, peerReq *ethpb.PeerRequest) (*ethpb.DebugPeerResponse, error) {
@@ -24,7 +24,7 @@ func (ds *Server) GetPeer(_ context.Context, peerReq *ethpb.PeerRequest) (*ethpb
 	return ds.getPeer(pid)
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListPeers returns all peers known to the host node, regardless of if they are connected/
 // disconnected.

beacon-chain/rpc/prysm/v1alpha1/debug/state.go

@@ -10,7 +10,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetBeaconState retrieves an ssz-encoded beacon state
 // from the beacon node by either a slot or block root.

beacon-chain/rpc/prysm/v1alpha1/node/server.go

@@ -49,7 +49,7 @@ type Server struct {
 	BeaconMonitoringPort int
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetHealth checks the health of the node
 func (ns *Server) GetHealth(ctx context.Context, request *ethpb.HealthRequest) (*empty.Empty, error) {
@@ -80,7 +80,7 @@ func (ns *Server) GetHealth(ctx context.Context, request *ethpb.HealthRequest) (
 	return &empty.Empty{}, status.Errorf(codes.Unavailable, "service unavailable")
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetSyncStatus checks the current network sync status of the node.
 func (ns *Server) GetSyncStatus(_ context.Context, _ *empty.Empty) (*ethpb.SyncStatus, error) {
@@ -89,7 +89,7 @@ func (ns *Server) GetSyncStatus(_ context.Context, _ *empty.Empty) (*ethpb.SyncS
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetGenesis fetches genesis chain information of Ethereum. Returns unix timestamp 0
 // if a genesis time has yet to be determined.
@@ -115,7 +115,7 @@ func (ns *Server) GetGenesis(ctx context.Context, _ *empty.Empty) (*ethpb.Genesi
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetVersion checks the version information of the beacon node.
 func (_ *Server) GetVersion(_ context.Context, _ *empty.Empty) (*ethpb.Version, error) {
@@ -124,7 +124,7 @@ func (_ *Server) GetVersion(_ context.Context, _ *empty.Empty) (*ethpb.Version,
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListImplementedServices lists the services implemented and enabled by this node.
 //
@@ -143,7 +143,7 @@ func (ns *Server) ListImplementedServices(_ context.Context, _ *empty.Empty) (*e
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetHost returns the p2p data on the current local and host peer.
 func (ns *Server) GetHost(_ context.Context, _ *empty.Empty) (*ethpb.HostData, error) {
@@ -168,7 +168,7 @@ func (ns *Server) GetHost(_ context.Context, _ *empty.Empty) (*ethpb.HostData, e
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetPeer returns the data known about the peer defined by the provided peer id.
 func (ns *Server) GetPeer(_ context.Context, peerReq *ethpb.PeerRequest) (*ethpb.Peer, error) {
@@ -215,7 +215,7 @@ func (ns *Server) GetPeer(_ context.Context, peerReq *ethpb.PeerRequest) (*ethpb
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ListPeers lists the peers connected to this node.
 func (ns *Server) ListPeers(ctx context.Context, _ *empty.Empty) (*ethpb.Peers, error) {
@@ -270,7 +270,7 @@ func (ns *Server) ListPeers(ctx context.Context, _ *empty.Empty) (*ethpb.Peers,
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetETH1ConnectionStatus gets data about the ETH1 endpoints.
 func (ns *Server) GetETH1ConnectionStatus(_ context.Context, _ *empty.Empty) (*ethpb.ETH1ConnectionStatus, error) {
@@ -286,7 +286,7 @@ func (ns *Server) GetETH1ConnectionStatus(_ context.Context, _ *empty.Empty) (*e
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // StreamBeaconLogs from the beacon node via a gRPC server-side stream.
 // DEPRECATED: This endpoint doesn't appear to be used and have been marked for deprecation.

beacon-chain/rpc/prysm/v1alpha1/validator/BUILD.bazel

@@ -103,7 +103,6 @@ go_library(
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_grpc//codes:go_default_library",
         "@org_golang_google_grpc//status:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",

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

@@ -17,7 +17,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitAggregateSelectionProof is called by a validator when its assigned to be an aggregator.
 // The aggregator submits the selection proof to obtain the aggregated attestation
@@ -55,7 +55,7 @@ func (vs *Server) SubmitAggregateSelectionProof(ctx context.Context, req *ethpb.
 	return &ethpb.AggregateSelectionResponse{AggregateAndProof: attAndProof}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitAggregateSelectionProofElectra is called by a validator when its assigned to be an aggregator.
 // The aggregator submits the selection proof to obtain the aggregated attestation
@@ -149,7 +149,7 @@ func (vs *Server) processAggregateSelection(ctx context.Context, req *ethpb.Aggr
 	return indexInCommittee, validatorIndex, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitSignedAggregateSelectionProof is called by a validator to broadcast a signed
 // aggregated and proof object.
@@ -163,7 +163,7 @@ func (vs *Server) SubmitSignedAggregateSelectionProof(
 	return &ethpb.SignedAggregateSubmitResponse{}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitSignedAggregateSelectionProofElectra is called by a validator to broadcast a signed
 // aggregated and proof object.

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

@@ -22,7 +22,7 @@ import (
 	"google.golang.org/protobuf/types/known/emptypb"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetAttestationData requests that the beacon node produce an attestation data object,
 // which the validator acting as an attester will then sign.
@@ -44,7 +44,7 @@ func (vs *Server) GetAttestationData(ctx context.Context, req *ethpb.Attestation
 	return res, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ProposeAttestation is a function called by an attester to vote
 // on a block via an attestation object as defined in the Ethereum specification.
@@ -74,7 +74,7 @@ func (vs *Server) ProposeAttestation(ctx context.Context, att *ethpb.Attestation
 	return resp, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ProposeAttestationElectra is a function called by an attester to vote
 // on a block via an attestation object as defined in the Ethereum specification.
@@ -114,7 +114,7 @@ func (vs *Server) ProposeAttestationElectra(ctx context.Context, singleAtt *ethp
 	return resp, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubscribeCommitteeSubnets subscribes to the committee ID subnet given subscribe request.
 func (vs *Server) SubscribeCommitteeSubnets(ctx context.Context, req *ethpb.CommitteeSubnetsSubscribeRequest) (*emptypb.Empty, error) {

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

@@ -9,13 +9,12 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "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/grpc/codes"
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // StreamBlocksAltair to clients every single time a block is received by the beacon node.
 func (vs *Server) StreamBlocksAltair(req *ethpb.StreamBlocksRequest, stream ethpb.BeaconNodeValidator_StreamBlocksAltairServer) error {
@@ -50,7 +49,7 @@ func (vs *Server) StreamBlocksAltair(req *ethpb.StreamBlocksRequest, stream ethp
 	}
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // StreamSlots sends a the block's slot and dependent roots to clients every single time a block is received by the beacon node.
 func (vs *Server) StreamSlots(req *ethpb.StreamSlotsRequest, stream ethpb.BeaconNodeValidator_StreamSlotsServer) error {
@@ -67,6 +66,7 @@ func (vs *Server) StreamSlots(req *ethpb.StreamSlotsRequest, stream ethpb.Beacon
 		select {
 		case ev := <-ch:
 			var s primitives.Slot
+			var currDependentRoot, prevDependentRoot [32]byte
 			if req.VerifiedOnly {
 				if ev.Type != statefeed.BlockProcessed {
 					continue
@@ -76,6 +76,8 @@ func (vs *Server) StreamSlots(req *ethpb.StreamSlotsRequest, stream ethpb.Beacon
 					continue
 				}
 				s = data.Slot
+				currDependentRoot = data.CurrDependentRoot
+				prevDependentRoot = data.PrevDependentRoot
 			} else {
 				if ev.Type != blockfeed.ReceivedBlock {
 					continue
@@ -85,24 +87,14 @@ func (vs *Server) StreamSlots(req *ethpb.StreamSlotsRequest, stream ethpb.Beacon
 					continue
 				}
 				s = data.SignedBlock.Block().Slot()
-			}
-			currEpoch := slots.ToEpoch(s)
-			currDepRoot, err := vs.ForkchoiceFetcher.DependentRoot(currEpoch)
-			if err != nil {
-				return status.Errorf(codes.Internal, "Could not get dependent root: %v", err)
-			}
-			prevDepRoot := currDepRoot
-			if currEpoch > 0 {
-				prevDepRoot, err = vs.ForkchoiceFetcher.DependentRoot(currEpoch - 1)
-				if err != nil {
-					return status.Errorf(codes.Internal, "Could not get dependent root: %v", err)
-				}
+				currDependentRoot = data.CurrDependentRoot
+				prevDependentRoot = data.PrevDependentRoot
 			}
 			if err := stream.Send(
 				&ethpb.StreamSlotsResponse{
 					Slot:                      s,
-					PreviousDutyDependentRoot: prevDepRoot[:],
-					CurrentDutyDependentRoot:  currDepRoot[:],
+					PreviousDutyDependentRoot: prevDependentRoot[:],
+					CurrentDutyDependentRoot:  currDependentRoot[:],
 				}); err != nil {
 				return status.Errorf(codes.Unavailable, "Could not send over stream: %v", err)
 			}

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

@@ -9,6 +9,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/core"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"google.golang.org/grpc/codes"
@@ -16,7 +17,7 @@ import (
 	"google.golang.org/protobuf/types/known/emptypb"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetDuties returns the duties assigned to a list of validators specified
 // in the request object.
@@ -80,9 +81,11 @@ func (vs *Server) duties(ctx context.Context, req *ethpb.DutiesRequest) (*ethpb.
 		return nil, status.Errorf(codes.Internal, "Could not compute proposer slots: %v", err)
 	}
 
+	ctx, span := trace.StartSpan(ctx, "getDuties.BuildResponse")
+	defer span.End()
+
 	validatorAssignments := make([]*ethpb.DutiesResponse_Duty, 0, len(req.PublicKeys))
 	nextValidatorAssignments := make([]*ethpb.DutiesResponse_Duty, 0, len(req.PublicKeys))
-
 	for _, pubKey := range req.PublicKeys {
 		if ctx.Err() != nil {
 			return nil, status.Errorf(codes.Aborted, "Could not continue fetching assignments: %v", ctx.Err())
@@ -178,7 +181,7 @@ func (vs *Server) duties(ctx context.Context, req *ethpb.DutiesRequest) (*ethpb.
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // AssignValidatorToSubnet checks the status and pubkey of a particular validator
 // to discern whether persistent subnets need to be registered for them.

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

@@ -12,7 +12,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ProposeExit proposes an exit for a validator.
 func (vs *Server) ProposeExit(ctx context.Context, req *ethpb.SignedVoluntaryExit) (*ethpb.ProposeExitResponse, error) {

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

@@ -45,7 +45,7 @@ const (
 	defaultBuilderBoostFactor = primitives.Gwei(100)
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetBeaconBlock is called by a proposer during its assigned slot to request a block to sign
 // by passing in the slot and the signed randao reveal of the slot.
@@ -271,7 +271,7 @@ func (vs *Server) BuildBlockParallel(ctx context.Context, sBlk interfaces.Signed
 	return vs.constructGenericBeaconBlock(sBlk, bundle, winningBid)
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ProposeBeaconBlock handles the proposal of beacon blocks.
 func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSignedBeaconBlock) (*ethpb.ProposeResponse, error) {
@@ -412,7 +412,7 @@ func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethp
 	return eg.Wait()
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // PrepareBeaconProposer caches and updates the fee recipient for the given proposer.
 func (vs *Server) PrepareBeaconProposer(
@@ -449,7 +449,7 @@ func (vs *Server) PrepareBeaconProposer(
 	return &emptypb.Empty{}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetFeeRecipientByPubKey returns a fee recipient from the beacon node's settings or db based on a given public key
 func (vs *Server) GetFeeRecipientByPubKey(ctx context.Context, request *ethpb.FeeRecipientByPubKeyRequest) (*ethpb.FeeRecipientByPubKeyResponse, error) {
@@ -506,7 +506,7 @@ func (vs *Server) computeStateRoot(ctx context.Context, block interfaces.ReadOnl
 	return root[:], nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitValidatorRegistrations submits validator registrations.
 func (vs *Server) SubmitValidatorRegistrations(ctx context.Context, reg *ethpb.SignedValidatorRegistrationsV1) (*emptypb.Empty, error) {

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

@@ -82,7 +82,7 @@ type Server struct {
 	AttestationStateFetcher blockchain.AttestationStateFetcher
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // WaitForActivation checks if a validator public key exists in the active validator registry of the current
 // beacon state, if not, then it creates a stream which listens for canonical states which contain
@@ -132,7 +132,7 @@ func (vs *Server) WaitForActivation(req *ethpb.ValidatorActivationRequest, strea
 	}
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ValidatorIndex is called by a validator to get its index location in the beacon state.
 func (vs *Server) ValidatorIndex(ctx context.Context, req *ethpb.ValidatorIndexRequest) (*ethpb.ValidatorIndexResponse, error) {
@@ -151,7 +151,7 @@ func (vs *Server) ValidatorIndex(ctx context.Context, req *ethpb.ValidatorIndexR
 	return &ethpb.ValidatorIndexResponse{Index: index}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // DomainData fetches the current domain version information from the beacon state.
 func (vs *Server) DomainData(ctx context.Context, request *ethpb.DomainRequest) (*ethpb.DomainResponse, error) {
@@ -183,7 +183,7 @@ func (vs *Server) DomainData(ctx context.Context, request *ethpb.DomainRequest)
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // WaitForChainStart queries the logs of the Deposit Contract in order to verify the beacon chain
 // has started its runtime and validators begin their responsibilities. If it has not, it then

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

@@ -29,7 +29,7 @@ var nonExistentIndex = primitives.ValidatorIndex(^uint64(0))
 
 var errParticipation = status.Errorf(codes.Internal, "Failed to obtain epoch participation")
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ValidatorStatus returns the validator status of the current epoch.
 // The status response can be one of the following:
@@ -54,7 +54,7 @@ func (vs *Server) ValidatorStatus(
 	return vStatus, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // MultipleValidatorStatus is the same as ValidatorStatus. Supports retrieval of multiple
 // validator statuses. Takes a list of public keys or a list of validator indices.
@@ -104,7 +104,7 @@ func (vs *Server) MultipleValidatorStatus(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // CheckDoppelGanger checks if the provided keys are currently active in the network.
 func (vs *Server) CheckDoppelGanger(ctx context.Context, req *ethpb.DoppelGangerRequest) (*ethpb.DoppelGangerResponse, error) {

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

@@ -12,7 +12,7 @@ import (
 	"google.golang.org/protobuf/types/known/emptypb"
 )
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetSyncMessageBlockRoot retrieves the sync committee block root of the beacon chain.
 func (vs *Server) GetSyncMessageBlockRoot(
@@ -34,7 +34,7 @@ func (vs *Server) GetSyncMessageBlockRoot(
 	}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitSyncMessage submits the sync committee message to the network.
 // It also saves the sync committee message into the pending pool for block inclusion.
@@ -45,7 +45,7 @@ func (vs *Server) SubmitSyncMessage(ctx context.Context, msg *ethpb.SyncCommitte
 	return &emptypb.Empty{}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetSyncSubcommitteeIndex is called by a sync committee participant to get
 // its subcommittee index for sync message aggregation duty.
@@ -63,7 +63,7 @@ func (vs *Server) GetSyncSubcommitteeIndex(
 	return &ethpb.SyncSubcommitteeIndexResponse{Indices: indices}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // GetSyncCommitteeContribution is called by a sync committee aggregator
 // to retrieve sync committee contribution object.
@@ -106,7 +106,7 @@ func (vs *Server) GetSyncCommitteeContribution(
 	return contribution, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // SubmitSignedContributionAndProof is called by a sync committee aggregator
 // to submit signed contribution and proof object.
@@ -120,7 +120,7 @@ func (vs *Server) SubmitSignedContributionAndProof(
 	return &emptypb.Empty{}, nil
 }
 
-// Deprecated: gRPC API will still be supported for some time, most likely until v8 in 2026, but will be eventually removed in favor of REST API.
+// Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // AggregatedSigAndAggregationBits returns the aggregated signature and aggregation bits
 // associated with a particular set of sync committee messages.

beacon-chain/rpc/service.go

@@ -47,7 +47,7 @@ import (
 	grpcprometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/plugin/ocgrpc"
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/peer"
@@ -146,7 +146,7 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 	log.WithField("address", address).Info("gRPC server listening on port")
 
 	opts := []grpc.ServerOption{
-		grpc.StatsHandler(&ocgrpc.ServerHandler{}),
+		grpc.StatsHandler(otelgrpc.NewServerHandler()),
 		grpc.StreamInterceptor(middleware.ChainStreamServer(
 			recovery.StreamServerInterceptor(
 				recovery.WithRecoveryHandlerContext(tracing.RecoveryHandlerFunc),

beacon-chain/state/interfaces.go

@@ -68,7 +68,7 @@ type ReadOnlyBeaconState interface {
 	Slot() primitives.Slot
 	Fork() *ethpb.Fork
 	LatestBlockHeader() *ethpb.BeaconBlockHeader
-	HistoricalRoots() ([][]byte, error)
+	HistoricalRoots() [][]byte
 	HistoricalSummaries() ([]*ethpb.HistoricalSummary, error)
 	Slashings() []uint64
 	FieldReferencesCount() map[string]uint64

beacon-chain/state/state-native/getters_misc.go

@@ -73,15 +73,15 @@ func (b *BeaconState) forkVal() *ethpb.Fork {
 }
 
 // HistoricalRoots based on epochs stored in the beacon state.
-func (b *BeaconState) HistoricalRoots() ([][]byte, error) {
+func (b *BeaconState) HistoricalRoots() [][]byte {
 	if b.historicalRoots == nil {
-		return nil, nil
+		return nil
 	}
 
 	b.lock.RLock()
 	defer b.lock.RUnlock()
 
-	return b.historicalRoots.Slice(), nil
+	return b.historicalRoots.Slice()
 }
 
 // HistoricalSummaries of the beacon state.