fixing error inconsistency

* Validator custody: Update to the latest specfication.

* Update beacon-chain/blockchain/process_block.go

Co-authored-by: terence <terence@prysmaticlabs.com>

* Fix James' comment.

* Fix James' comment.

* Fix James' comment.

---------

Co-authored-by: terence <terence@prysmaticlabs.com>
Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>

WORKSPACE

@@ -190,7 +190,7 @@ load("@rules_oci//oci:pull.bzl", "oci_pull")
 # A multi-arch base image
 oci_pull(
     name = "linux_debian11_multiarch_base",  # Debian bullseye
-    digest = "sha256:b82f113425c5b5c714151aaacd8039bc141821cdcd3c65202d42bdf9c43ae60b",  # 2023-12-12
+    digest = "sha256:55a5e011b2c4246b4c51e01fcc2b452d151e03df052e357465f0392fcd59fddf",
     image = "gcr.io/prysmaticlabs/distroless/cc-debian11",
     platforms = [
         "linux/amd64",
@@ -208,7 +208,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()
 
 go_register_toolchains(
-    go_version = "1.24.0",
+    go_version = "1.24.5",
     nogo = "@//:nogo",
 )
 

api/server/structs/BUILD.bazel

@@ -36,6 +36,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
         "//container/slice:go_default_library",
+        "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
         "//proto/engine/v1:go_default_library",

api/server/structs/conversions.go

@@ -10,6 +10,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/validator"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
+	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/math"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -699,6 +700,11 @@ func (m *SyncCommitteeMessage) ToConsensus() (*eth.SyncCommitteeMessage, error)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Signature")
 	}
+	// Add validation to check if the signature is valid BLS format
+	_, err = bls.SignatureFromBytes(sig)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
 
 	return &eth.SyncCommitteeMessage{
 		Slot:           primitives.Slot(slot),

api/server/structs/endpoints_beacon.go

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

api/server/structs/endpoints_node.go

@@ -27,6 +27,8 @@ type Identity struct {
 type Metadata struct {
 	SeqNumber string `json:"seq_number"`
 	Attnets   string `json:"attnets"`
+	Syncnets  string `json:"syncnets,omitempty"`
+	Cgc       string `json:"custody_group_count,omitempty"`
 }
 
 type GetPeerResponse struct {

beacon-chain/blockchain/BUILD.bazel

@@ -73,6 +73,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -194,6 +195,7 @@ go_test(
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_ethereum_go_ethereum//core/types:go_default_library",
         "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",

beacon-chain/blockchain/execution_engine.go

@@ -174,6 +174,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
 		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), arg.headBlock, arg.headRoot, nextSlot)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -102,8 +102,6 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 		log.WithError(err).Error("Could not save head")
 	}
 
-	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)
 	return nil

beacon-chain/blockchain/kzg/trusted_setup.go

@@ -11,7 +11,7 @@ import (
 )
 
 var (
-	// https://github.com/ethereum/consensus-specs/blob/dev/presets/mainnet/trusted_setups/trusted_setup_4096.json
+	// https://github.com/ethereum/consensus-specs/blob/master/presets/mainnet/trusted_setups/trusted_setup_4096.json
 	//go:embed trusted_setup_4096.json
 	embeddedTrustedSetup []byte // 1.2Mb
 	kzgContext           *GoKZG.Context

beacon-chain/blockchain/options.go

@@ -7,7 +7,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
@@ -36,7 +35,7 @@ func WithMaxGoroutines(x int) Option {
 // WithLCStore for light client store access.
 func WithLCStore() Option {
 	return func(s *Service) error {
-		s.lcStore = lightclient.NewLightClientStore(s.cfg.BeaconDB)
+		s.lcStore = lightclient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 		return nil
 	}
 }
@@ -235,14 +234,6 @@ func WithSyncChecker(checker Checker) Option {
 	}
 }
 
-// WithCustodyInfo sets the custody info for the blockchain service.
-func WithCustodyInfo(custodyInfo *peerdas.CustodyInfo) Option {
-	return func(s *Service) error {
-		s.cfg.CustodyInfo = custodyInfo
-		return nil
-	}
-}
-
 // WithSlasherEnabled sets whether the slasher is enabled or not.
 func WithSlasherEnabled(enabled bool) Option {
 	return func(s *Service) error {

beacon-chain/blockchain/process_block.go

@@ -666,10 +666,11 @@ func (s *Service) areDataColumnsAvailable(
 	root [fieldparams.RootLength]byte,
 	block interfaces.ReadOnlyBeaconBlock,
 ) error {
-	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+
+	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS
 	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
 	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
-
 	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
 		return nil
 	}
@@ -690,16 +691,20 @@ func (s *Service) areDataColumnsAvailable(
 	}
 
 	// All columns to sample need to be available for the block to be considered available.
-	// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/das-core.md#custody-sampling
 	nodeID := s.cfg.P2P.NodeID()
 
-	// Prevent custody group count to change during the rest of the function.
-	s.cfg.CustodyInfo.Mut.RLock()
-	defer s.cfg.CustodyInfo.Mut.RUnlock()
-
 	// Get the custody group sampling size for the node.
-	custodyGroupSamplingSize := s.cfg.CustodyInfo.CustodyGroupSamplingSize(peerdas.Actual)
-	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupSamplingSize)
+	custodyGroupCount, err := s.cfg.P2P.CustodyGroupCount()
+	if err != nil {
+		return errors.Wrap(err, "custody group count")
+	}
+
+	// Compute the sampling size.
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#custody-sampling
+	samplingSize := max(samplesPerSlot, custodyGroupCount)
+
+	// Get the peer info for the node.
+	peerInfo, _, err := peerdas.Info(nodeID, samplingSize)
 	if err != nil {
 		return errors.Wrap(err, "peer info")
 	}

beacon-chain/blockchain/process_block_helpers.go

@@ -1,7 +1,6 @@
 package blockchain
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"strings"
@@ -198,8 +197,7 @@ func (s *Service) processLightClientFinalityUpdate(
 
 	finalizedCheckpoint := attestedState.FinalizedCheckpoint()
 
-	// Check if the finalized checkpoint has changed
-	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+	if finalizedCheckpoint == nil {
 		return nil
 	}
 
@@ -224,17 +222,7 @@ func (s *Service) processLightClientFinalityUpdate(
 		return nil
 	}
 
-	log.Debug("Saving new light client finality update")
-	s.lcStore.SetLastFinalityUpdate(newUpdate)
-
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		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")
-	}
+	s.lcStore.SetLastFinalityUpdate(newUpdate, true)
 
 	return nil
 }
@@ -266,17 +254,7 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return nil
 	}
 
-	log.Debug("Saving new light client optimistic update")
-	s.lcStore.SetLastOptimisticUpdate(newUpdate)
-
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientOptimisticUpdate,
-		Data: newUpdate,
-	})
-
-	if err = s.cfg.P2P.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
-		return errors.Wrap(err, "could not broadcast light client optimistic update")
-	}
+	s.lcStore.SetLastOptimisticUpdate(newUpdate, true)
 
 	return nil
 }

beacon-chain/blockchain/process_block_test.go

@@ -2894,7 +2894,6 @@ func TestIsDataAvailable(t *testing.T) {
 		}
 
 		params := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
 			columnsToSave:           indices,
 			blobKzgCommitmentsCount: 3,
 		}
@@ -2907,7 +2906,6 @@ func TestIsDataAvailable(t *testing.T) {
 
 	t.Run("Fulu - no missing data columns", func(t *testing.T) {
 		params := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
 			columnsToSave:           []uint64{1, 17, 19, 42, 75, 87, 102, 117, 119}, // 119 is not needed
 			blobKzgCommitmentsCount: 3,
 		}
@@ -2922,7 +2920,7 @@ func TestIsDataAvailable(t *testing.T) {
 		startWaiting := make(chan bool)
 
 		testParams := testIsAvailableParams{
-			options:       []Option{WithCustodyInfo(&peerdas.CustodyInfo{}), WithStartWaitingDataColumnSidecars(startWaiting)},
+			options:       []Option{WithStartWaitingDataColumnSidecars(startWaiting)},
 			columnsToSave: []uint64{1, 17, 19, 75, 102, 117, 119}, // 119 is not needed, 42 and 87 are missing
 
 			blobKzgCommitmentsCount: 3,
@@ -2959,6 +2957,9 @@ func TestIsDataAvailable(t *testing.T) {
 			require.NoError(t, err)
 		}()
 
+		ctx, cancel := context.WithTimeout(ctx, time.Second*2)
+		defer cancel()
+
 		err = service.isDataAvailable(ctx, root, signed)
 		require.NoError(t, err)
 	})
@@ -2971,10 +2972,6 @@ func TestIsDataAvailable(t *testing.T) {
 
 		startWaiting := make(chan bool)
 
-		var custodyInfo peerdas.CustodyInfo
-		custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(cgc)
-		custodyInfo.ToAdvertiseGroupCount.Set(cgc)
-
 		minimumColumnsCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
 		indices := make([]uint64, 0, minimumColumnsCountToReconstruct-missingColumns)
 
@@ -2983,12 +2980,14 @@ func TestIsDataAvailable(t *testing.T) {
 		}
 
 		testParams := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&custodyInfo), WithStartWaitingDataColumnSidecars(startWaiting)},
+			options:                 []Option{WithStartWaitingDataColumnSidecars(startWaiting)},
 			columnsToSave:           indices,
 			blobKzgCommitmentsCount: 3,
 		}
 
 		ctx, _, service, root, signed := testIsAvailableSetup(t, testParams)
+		_, _, err := service.cfg.P2P.UpdateCustodyInfo(0, cgc)
+		require.NoError(t, err)
 		block := signed.Block()
 		slot := block.Slot()
 		proposerIndex := block.ProposerIndex()
@@ -3020,6 +3019,9 @@ func TestIsDataAvailable(t *testing.T) {
 			require.NoError(t, err)
 		}()
 
+		ctx, cancel := context.WithTimeout(ctx, time.Second*2)
+		defer cancel()
+
 		err = service.isDataAvailable(ctx, root, signed)
 		require.NoError(t, err)
 	})
@@ -3028,7 +3030,7 @@ func TestIsDataAvailable(t *testing.T) {
 		startWaiting := make(chan bool)
 
 		params := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{}), WithStartWaitingDataColumnSidecars(startWaiting)},
+			options:                 []Option{WithStartWaitingDataColumnSidecars(startWaiting)},
 			blobKzgCommitmentsCount: 3,
 		}
 
@@ -3170,7 +3172,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 
 			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
 				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-				s.lcStore = &lightClient.Store{}
+				s.lcStore = lightClient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 
 				var oldActualUpdate interfaces.LightClientOptimisticUpdate
 				var err error
@@ -3246,39 +3248,39 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 			expectReplace: true,
 		},
 		{
-			name:          "Old update is better - age - no supermajority",
+			name:          "Old update is better - finalized slot is higher",
 			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
 			newOptions:    []util.LightClientOption{},
 			expectReplace: false,
 		},
 		{
-			name:          "Old update is better - age - both supermajority",
-			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
-			newOptions:    []util.LightClientOption{util.WithSupermajority()},
-			expectReplace: false,
-		},
-		{
-			name:          "Old update is better - supermajority",
-			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
+			name:          "Old update is better - attested slot is higher",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			newOptions:    []util.LightClientOption{},
 			expectReplace: false,
 		},
 		{
-			name:          "New update is better - age - both supermajority",
-			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
-			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
+			name:          "Old update is better - signature slot is higher",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedSignatureSlot(1)},
+			newOptions:    []util.LightClientOption{},
+			expectReplace: false,
+		},
+		{
+			name:          "New update is better - finalized slot is higher",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			expectReplace: true,
 		},
 		{
-			name:          "New update is better - age - no supermajority",
+			name:          "New update is better - attested slot is higher",
 			oldOptions:    []util.LightClientOption{},
-			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			expectReplace: true,
 		},
 		{
-			name:          "New update is better - supermajority",
+			name:          "New update is better - signature slot is higher",
 			oldOptions:    []util.LightClientOption{},
-			newOptions:    []util.LightClientOption{util.WithSupermajority()},
+			newOptions:    []util.LightClientOption{util.WithIncreasedSignatureSlot(1)},
 			expectReplace: true,
 		},
 	}
@@ -3310,7 +3312,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 
 			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
 				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-				s.lcStore = &lightClient.Store{}
+				s.lcStore = lightClient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 
 				var actualOldUpdate, actualNewUpdate interfaces.LightClientFinalityUpdate
 				var err error

beacon-chain/blockchain/receive_attestation.go

@@ -177,7 +177,7 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 	for _, a := range atts {
 		// Based on the spec, don't process the attestation until the subsequent slot.
 		// This delays consideration in the fork choice until their slot is in the past.
-		// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/fork-choice.md#validate_on_attestation
+		// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/fork-choice.md#validate_on_attestation
 		nextSlot := a.GetData().Slot + 1
 		if err := slots.VerifyTime(s.genesisTime, nextSlot, disparity); err != nil {
 			continue

beacon-chain/blockchain/receive_data_column.go

@@ -15,7 +15,6 @@ func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataC
 }
 
 // ReceiveDataColumn receives a single data column.
-// (It is only a wrapper around ReceiveDataColumns.)
 func (s *Service) ReceiveDataColumn(dataColumnSidecar blocks.VerifiedRODataColumn) error {
 	if err := s.dataColumnStorage.Save([]blocks.VerifiedRODataColumn{dataColumnSidecar}); err != nil {
 		return errors.Wrap(err, "save data column sidecars")

beacon-chain/blockchain/service.go

@@ -16,7 +16,6 @@ import (
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
@@ -31,6 +30,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -97,7 +97,6 @@ type config struct {
 	FinalizedStateAtStartUp state.BeaconState
 	ExecutionEngineCaller   execution.EngineCaller
 	SyncChecker             Checker
-	CustodyInfo             *peerdas.CustodyInfo
 }
 
 // Checker is an interface used to determine if a node is in initial sync
@@ -296,6 +295,20 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err := s.clockSetter.SetClock(startup.NewClock(s.genesisTime, vr)); err != nil {
 		return errors.Wrap(err, "failed to initialize blockchain service")
 	}
+
+	if !params.FuluEnabled() {
+		return nil
+	}
+
+	earliestAvailableSlot, custodySubnetCount, err := s.updateCustodyInfoInDB(saved.Slot())
+	if err != nil {
+		return errors.Wrap(err, "could not get and save custody group count")
+	}
+
+	if _, _, err := s.cfg.P2P.UpdateCustodyInfo(earliestAvailableSlot, custodySubnetCount); err != nil {
+		return errors.Wrap(err, "update custody info")
+	}
+
 	return nil
 }
 
@@ -516,6 +529,57 @@ func (s *Service) removeStartupState() {
 	s.cfg.FinalizedStateAtStartUp = nil
 }
 
+// UpdateCustodyInfoInDB updates the custody information in the database.
+// It returns the (potentially updated) custody group count and the earliest available slot.
+func (s *Service) updateCustodyInfoInDB(slot primitives.Slot) (primitives.Slot, uint64, error) {
+	isSubscribedToAllDataSubnets := flags.Get().SubscribeAllDataSubnets
+
+	beaconConfig := params.BeaconConfig()
+	custodyRequirement := beaconConfig.CustodyRequirement
+
+	// Check if the node was previously subscribed to all data subnets, and if so,
+	// store the new status accordingly.
+	wasSubscribedToAllDataSubnets, err := s.cfg.BeaconDB.UpdateSubscribedToAllDataSubnets(s.ctx, isSubscribedToAllDataSubnets)
+	if err != nil {
+		log.WithError(err).Error("Could not update subscription status to all data subnets")
+	}
+
+	// Warn the user if the node was previously subscribed to all data subnets and is not any more.
+	if wasSubscribedToAllDataSubnets && !isSubscribedToAllDataSubnets {
+		log.Warnf(
+			"Because the flag `--%s` was previously used, the node will still subscribe to all data subnets.",
+			flags.SubscribeAllDataSubnets.Name,
+		)
+	}
+
+	// Compute the custody group count.
+	custodyGroupCount := custodyRequirement
+	if isSubscribedToAllDataSubnets {
+		custodyGroupCount = beaconConfig.NumberOfColumns
+	}
+
+	// Safely compute the fulu fork slot.
+	fuluForkSlot, err := fuluForkSlot()
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "fulu fork slot")
+	}
+
+	// If slot is before the fulu fork slot, then use the earliest stored slot as the reference slot.
+	if slot < fuluForkSlot {
+		slot, err = s.cfg.BeaconDB.EarliestSlot(s.ctx)
+		if err != nil {
+			return 0, 0, errors.Wrap(err, "earliest slot")
+		}
+	}
+
+	earliestAvailableSlot, custodyGroupCount, err := s.cfg.BeaconDB.UpdateCustodyInfo(s.ctx, slot, custodyGroupCount)
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "update custody info")
+	}
+
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
 func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db db.HeadAccessDatabase) {
 	currentTime := prysmTime.Now()
 	if currentTime.After(genesisTime) {
@@ -532,3 +596,19 @@ func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db d
 	}
 	go slots.CountdownToGenesis(ctx, genesisTime, uint64(gState.NumValidators()), gRoot)
 }
+
+func fuluForkSlot() (primitives.Slot, error) {
+	beaconConfig := params.BeaconConfig()
+
+	fuluForkEpoch := beaconConfig.FuluForkEpoch
+	if fuluForkEpoch == beaconConfig.FarFutureEpoch {
+		return beaconConfig.FarFutureSlot, nil
+	}
+
+	forkFuluSlot, err := slots.EpochStart(fuluForkEpoch)
+	if err != nil {
+		return 0, errors.Wrap(err, "epoch start")
+	}
+
+	return forkFuluSlot, nil
+}

beacon-chain/blockchain/setup_test.go

@@ -30,6 +30,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -54,6 +55,7 @@ type mockBroadcaster struct {
 
 type mockAccessor struct {
 	mockBroadcaster
+	mockCustodyManager
 	p2pTesting.MockPeerManager
 }
 
@@ -97,6 +99,43 @@ func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.Sig
 
 var _ p2p.Broadcaster = (*mockBroadcaster)(nil)
 
+// mockCustodyManager is a mock implementation of p2p.CustodyManager
+type mockCustodyManager struct {
+	mut                   sync.RWMutex
+	earliestAvailableSlot primitives.Slot
+	custodyGroupCount     uint64
+}
+
+func (dch *mockCustodyManager) EarliestAvailableSlot() (primitives.Slot, error) {
+	dch.mut.RLock()
+	defer dch.mut.RUnlock()
+
+	return dch.earliestAvailableSlot, nil
+}
+
+func (dch *mockCustodyManager) CustodyGroupCount() (uint64, error) {
+	dch.mut.RLock()
+	defer dch.mut.RUnlock()
+
+	return dch.custodyGroupCount, nil
+}
+
+func (dch *mockCustodyManager) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	dch.mut.Lock()
+	defer dch.mut.Unlock()
+
+	dch.earliestAvailableSlot = earliestAvailableSlot
+	dch.custodyGroupCount = custodyGroupCount
+
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
+func (dch *mockCustodyManager) CustodyGroupCountFromPeer(peer.ID) uint64 {
+	return 0
+}
+
+var _ p2p.CustodyManager = (*mockCustodyManager)(nil)
+
 type testServiceRequirements struct {
 	ctx     context.Context
 	db      db.Database

beacon-chain/core/electra/withdrawals.go

@@ -102,13 +102,13 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 			return nil, err
 		} else if n == params.BeaconConfig().PendingPartialWithdrawalsLimit && !isFullExitRequest {
 			// if the PendingPartialWithdrawalsLimit is met, the user would have paid for a partial withdrawal that's not included
-			log.Debugln("Skipping execution layer withdrawal request, PendingPartialWithdrawalsLimit reached")
+			log.Debug("Skipping execution layer withdrawal request, PendingPartialWithdrawalsLimit reached")
 			continue
 		}
 
 		vIdx, exists := st.ValidatorIndexByPubkey(bytesutil.ToBytes48(wr.ValidatorPubkey))
 		if !exists {
-			log.Debugf("Skipping execution layer withdrawal request, validator index for %s not found\n", hexutil.Encode(wr.ValidatorPubkey))
+			log.WithField("validator", hexutil.Encode(wr.ValidatorPubkey)).Debug("Skipping execution layer withdrawal request, validator index not found")
 			continue
 		}
 		validator, err := st.ValidatorAtIndexReadOnly(vIdx)
@@ -120,23 +120,23 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 		wc := validator.GetWithdrawalCredentials()
 		isCorrectSourceAddress := bytes.Equal(wc[12:], wr.SourceAddress)
 		if !hasCorrectCredential || !isCorrectSourceAddress {
-			log.Debugln("Skipping execution layer withdrawal request, wrong withdrawal credentials")
+			log.Debug("Skipping execution layer withdrawal request, wrong withdrawal credentials")
 			continue
 		}
 
 		// Verify the validator is active.
 		if !helpers.IsActiveValidatorUsingTrie(validator, currentEpoch) {
-			log.Debugln("Skipping execution layer withdrawal request, validator not active")
+			log.Debug("Skipping execution layer withdrawal request, validator not active")
 			continue
 		}
 		// Verify the validator has not yet submitted an exit.
 		if validator.ExitEpoch() != params.BeaconConfig().FarFutureEpoch {
-			log.Debugln("Skipping execution layer withdrawal request, validator has submitted an exit already")
+			log.Debug("Skipping execution layer withdrawal request, validator has submitted an exit already")
 			continue
 		}
 		// Verify the validator has been active long enough.
 		if currentEpoch < validator.ActivationEpoch().AddEpoch(params.BeaconConfig().ShardCommitteePeriod) {
-			log.Debugln("Skipping execution layer withdrawal request, validator has not been active long enough")
+			log.Debug("Skipping execution layer withdrawal request, validator has not been active long enough")
 			continue
 		}
 

beacon-chain/core/fulu/upgrade.go

@@ -15,7 +15,7 @@ import (
 )
 
 // UpgradeToFulu updates inputs a generic state to return the version Fulu state.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/fork.md#upgrading-the-state
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/fork.md#upgrading-the-state
 func UpgradeToFulu(ctx context.Context, beaconState state.BeaconState) (state.BeaconState, error) {
 	currentSyncCommittee, err := beaconState.CurrentSyncCommittee()
 	if err != nil {

beacon-chain/core/helpers/weak_subjectivity.go

@@ -206,9 +206,9 @@ func ParseWeakSubjectivityInputString(wsCheckpointString string) (*v1alpha1.Chec
 // MinEpochsForBlockRequests computes the number of epochs of block history that we need to maintain,
 // relative to the current epoch, per the p2p specs. This is used to compute the slot where backfill is complete.
 // value defined:
-// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#configuration
+// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#configuration
 // MIN_VALIDATOR_WITHDRAWABILITY_DELAY + CHURN_LIMIT_QUOTIENT // 2 (= 33024, ~5 months)
-// detailed rationale: https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
+// detailed rationale: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
 func MinEpochsForBlockRequests() primitives.Epoch {
 	return params.BeaconConfig().MinValidatorWithdrawabilityDelay +
 		primitives.Epoch(params.BeaconConfig().ChurnLimitQuotient/2)

beacon-chain/core/helpers/weak_subjectivity_test.go

@@ -292,7 +292,7 @@ func TestMinEpochsForBlockRequests(t *testing.T) {
 	params.SetActiveTestCleanup(t, params.MainnetConfig())
 	var expected primitives.Epoch = 33024
 	// expected value of 33024 via spec commentary:
-	// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
 	//	MIN_EPOCHS_FOR_BLOCK_REQUESTS is calculated using the arithmetic from compute_weak_subjectivity_period found in the weak subjectivity guide. Specifically to find this max epoch range, we use the worst case event of a very large validator size (>= MIN_PER_EPOCH_CHURN_LIMIT * CHURN_LIMIT_QUOTIENT).
 	//
 	//	MIN_EPOCHS_FOR_BLOCK_REQUESTS = (

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

@@ -10,8 +10,12 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client",
     visibility = ["//visibility:public"],
     deps = [
+        "//async/event:go_default_library",
+        "//beacon-chain/core/feed:go_default_library",
+        "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/db/iface:go_default_library",
         "//beacon-chain/execution:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -39,6 +43,9 @@ go_test(
     ],
     deps = [
         ":go_default_library",
+        "//async/event:go_default_library",
+        "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types:go_default_library",

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

@@ -750,7 +750,9 @@ func UpdateHasSupermajority(syncAggregate *pb.SyncAggregate) bool {
 	return numActiveParticipants*3 >= maxActiveParticipants*2
 }
 
-func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
+// IsFinalityUpdateValidForBroadcast checks if a finality update needs to be broadcasted.
+// It is also used to check if an incoming gossiped finality update is valid for forwarding and saving.
+func IsFinalityUpdateValidForBroadcast(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
 	if oldUpdate == nil {
 		return true
 	}
@@ -772,6 +774,35 @@ func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityU
 	return true
 }
 
+// IsBetterFinalityUpdate checks if the new finality update is better than the old one for saving.
+// This does not concern broadcasting, but rather the decision of whether to save the new update.
+// For broadcasting checks, use IsFinalityUpdateValidForBroadcast.
+func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
+	if oldUpdate == nil {
+		return true
+	}
+
+	// Full nodes SHOULD provide the LightClientFinalityUpdate with the highest attested_header.beacon.slot (if multiple, highest signature_slot)
+	newFinalizedSlot := newUpdate.FinalizedHeader().Beacon().Slot
+	newAttestedSlot := newUpdate.AttestedHeader().Beacon().Slot
+
+	oldFinalizedSlot := oldUpdate.FinalizedHeader().Beacon().Slot
+	oldAttestedSlot := oldUpdate.AttestedHeader().Beacon().Slot
+
+	if newFinalizedSlot < oldFinalizedSlot {
+		return false
+	}
+	if newFinalizedSlot == oldFinalizedSlot {
+		if newAttestedSlot < oldAttestedSlot {
+			return false
+		}
+		if newAttestedSlot == oldAttestedSlot && newUpdate.SignatureSlot() <= oldUpdate.SignatureSlot() {
+			return false
+		}
+	}
+	return true
+}
+
 func IsBetterOptimisticUpdate(newUpdate, oldUpdate interfaces.LightClientOptimisticUpdate) bool {
 	if oldUpdate == nil {
 		return true

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

@@ -4,7 +4,11 @@ import (
 	"context"
 	"sync"
 
+	"github.com/OffchainLabs/prysm/v6/async/event"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
+	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/iface"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
@@ -16,13 +20,17 @@ type Store struct {
 	mu sync.RWMutex
 
 	beaconDB             iface.HeadAccessDatabase
-	lastFinalityUpdate   interfaces.LightClientFinalityUpdate
-	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate
+	lastFinalityUpdate   interfaces.LightClientFinalityUpdate   // tracks the best finality update seen so far
+	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate // tracks the best optimistic update seen so far
+	p2p                  p2p.Accessor
+	stateFeed            event.SubscriberSender
 }
 
-func NewLightClientStore(db iface.HeadAccessDatabase) *Store {
+func NewLightClientStore(db iface.HeadAccessDatabase, p p2p.Accessor, e event.SubscriberSender) *Store {
 	return &Store{
-		beaconDB: db,
+		beaconDB:  db,
+		p2p:       p,
+		stateFeed: e,
 	}
 }
 
@@ -143,10 +151,23 @@ func (s *Store) SaveLightClientUpdate(ctx context.Context, period uint64, update
 	return nil
 }
 
-func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate) {
+func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate, broadcast bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+
+	if broadcast && IsFinalityUpdateValidForBroadcast(update, s.lastFinalityUpdate) {
+		if err := s.p2p.BroadcastLightClientFinalityUpdate(context.Background(), update); err != nil {
+			log.WithError(err).Error("Could not broadcast light client finality update")
+		}
+	}
+
 	s.lastFinalityUpdate = update
+	log.Debug("Saved new light client finality update")
+
+	s.stateFeed.Send(&feed.Event{
+		Type: statefeed.LightClientFinalityUpdate,
+		Data: update,
+	})
 }
 
 func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
@@ -155,10 +176,23 @@ func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
 	return s.lastFinalityUpdate
 }
 
-func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate) {
+func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate, broadcast bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+
+	if broadcast {
+		if err := s.p2p.BroadcastLightClientOptimisticUpdate(context.Background(), update); err != nil {
+			log.WithError(err).Error("Could not broadcast light client optimistic update")
+		}
+	}
+
 	s.lastOptimisticUpdate = update
+	log.Debug("Saved new light client optimistic update")
+
+	s.stateFeed.Send(&feed.Event{
+		Type: statefeed.LightClientOptimisticUpdate,
+		Data: update,
+	})
 }
 
 func (s *Store) LastOptimisticUpdate() interfaces.LightClientOptimisticUpdate {

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

@@ -3,7 +3,10 @@ package light_client_test
 import (
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/async/event"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -21,7 +24,7 @@ func TestLightClientStore(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 
 	// Initialize the light client store
-	lcStore := &lightClient.Store{}
+	lcStore := lightClient.NewLightClientStore(testDB.SetupDB(t), &p2pTesting.FakeP2P{}, new(event.Feed))
 
 	// Create test light client updates for Capella and Deneb
 	lCapella := util.NewTestLightClient(t, version.Capella)
@@ -45,24 +48,118 @@ func TestLightClientStore(t *testing.T) {
 	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
 
 	// Set and get finality with Capella update. Optimistic update should be nil
-	lcStore.SetLastFinalityUpdate(finUpdateCapella)
+	lcStore.SetLastFinalityUpdate(finUpdateCapella, false)
 	require.Equal(t, finUpdateCapella, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
 	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
 
 	// Set and get optimistic with Capella update. Finality update should be Capella
-	lcStore.SetLastOptimisticUpdate(opUpdateCapella)
+	lcStore.SetLastOptimisticUpdate(opUpdateCapella, false)
 	require.Equal(t, opUpdateCapella, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate is wrong")
 	require.Equal(t, finUpdateCapella, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
 
 	// Set and get finality and optimistic with Deneb update
-	lcStore.SetLastFinalityUpdate(finUpdateDeneb)
-	lcStore.SetLastOptimisticUpdate(opUpdateDeneb)
+	lcStore.SetLastFinalityUpdate(finUpdateDeneb, false)
+	lcStore.SetLastOptimisticUpdate(opUpdateDeneb, false)
 	require.Equal(t, finUpdateDeneb, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
 	require.Equal(t, opUpdateDeneb, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate is wrong")
-
-	// Set and get finality and optimistic with nil update
-	lcStore.SetLastFinalityUpdate(nil)
-	lcStore.SetLastOptimisticUpdate(nil)
-	require.IsNil(t, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should be nil")
-	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
+}
+
+func TestLightClientStore_SetLastFinalityUpdate(t *testing.T) {
+	p2p := p2pTesting.NewTestP2P(t)
+	lcStore := lightClient.NewLightClientStore(testDB.SetupDB(t), p2p, new(event.Feed))
+
+	// update 0 with basic data and no supermajority following an empty lastFinalityUpdate - should save and broadcast
+	l0 := util.NewTestLightClient(t, version.Altair)
+	update0, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l0.Ctx, l0.State, l0.Block, l0.AttestedState, l0.AttestedBlock, l0.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update0, lcStore.LastFinalityUpdate()), "update0 should be better than nil")
+	// update0 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update0, lcStore.LastFinalityUpdate()), "update0 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update0, true)
+	require.Equal(t, update0, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after setting a new last finality update when previous is nil")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 1 with same finality slot, increased attested slot, and no supermajority - should save but not broadcast
+	l1 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(1))
+	update1, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l1.Ctx, l1.State, l1.Block, l1.AttestedState, l1.AttestedBlock, l1.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update1, update0), "update1 should be better than update0")
+	// update1 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update1, lcStore.LastFinalityUpdate()), "update1 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update1, true)
+	require.Equal(t, update1, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called after setting a new last finality update without supermajority")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 2 with same finality slot, increased attested slot, and supermajority - should save and broadcast
+	l2 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(2), util.WithSupermajority())
+	update2, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l2.Ctx, l2.State, l2.Block, l2.AttestedState, l2.AttestedBlock, l2.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update2, update1), "update2 should be better than update1")
+	// update2 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update2, lcStore.LastFinalityUpdate()), "update2 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update2, true)
+	require.Equal(t, update2, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after setting a new last finality update with supermajority")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 3 with same finality slot, increased attested slot, and supermajority - should save but not broadcast
+	l3 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(3), util.WithSupermajority())
+	update3, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l3.Ctx, l3.State, l3.Block, l3.AttestedState, l3.AttestedBlock, l3.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update3, update2), "update3 should be better than update2")
+	// update3 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update3, lcStore.LastFinalityUpdate()), "update3 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update3, true)
+	require.Equal(t, update3, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been when previous was already broadcast")
+
+	// update 4 with increased finality slot, increased attested slot, and supermajority - should save and broadcast
+	l4 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(1), util.WithSupermajority())
+	update4, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l4.Ctx, l4.State, l4.Block, l4.AttestedState, l4.AttestedBlock, l4.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update4, update3), "update4 should be better than update3")
+	// update4 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update4, lcStore.LastFinalityUpdate()), "update4 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update4, true)
+	require.Equal(t, update4, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after a new finality update with increased finality slot")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 5 with the same new finality slot, increased attested slot, and supermajority - should save but not broadcast
+	l5 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(2), util.WithSupermajority())
+	update5, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l5.Ctx, l5.State, l5.Block, l5.AttestedState, l5.AttestedBlock, l5.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update5, update4), "update5 should be better than update4")
+	// update5 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update5, lcStore.LastFinalityUpdate()), "update5 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update5, true)
+	require.Equal(t, update5, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called when previous was already broadcast with supermajority")
+
+	// update 6 with the same new finality slot, increased attested slot, and no supermajority - should save but not broadcast
+	l6 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(3))
+	update6, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l6.Ctx, l6.State, l6.Block, l6.AttestedState, l6.AttestedBlock, l6.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update6, update5), "update6 should be better than update5")
+	// update6 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update6, lcStore.LastFinalityUpdate()), "update6 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update6, true)
+	require.Equal(t, update6, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called when previous was already broadcast with supermajority")
 }

beacon-chain/core/peerdas/BUILD.bazel

@@ -16,7 +16,6 @@ go_library(
     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",
@@ -53,7 +52,6 @@ go_test(
         ":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",

beacon-chain/core/peerdas/das_core.go

@@ -31,27 +31,20 @@ var (
 	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
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#get_custody_groups
 func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error) {
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
 
 	// Check if the custody group count is larger than the number of custody groups.
-	if custodyGroupCount > numberOfCustodyGroup {
+	if custodyGroupCount > numberOfCustodyGroups {
 		return nil, ErrCustodyGroupCountTooLarge
 	}
 
 	// Shortcut if all custody groups are needed.
-	if custodyGroupCount == numberOfCustodyGroup {
-		custodyGroups := make([]uint64, 0, numberOfCustodyGroup)
-		for i := range numberOfCustodyGroup {
+	if custodyGroupCount == numberOfCustodyGroups {
+		custodyGroups := make([]uint64, 0, numberOfCustodyGroups)
+		for i := range numberOfCustodyGroups {
 			custodyGroups = append(custodyGroups, i)
 		}
 
@@ -73,7 +66,7 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 		hashedCurrentId := hash.Hash(currentIdBytesLittleEndian)
 
 		// Get the custody group ID.
-		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroup
+		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroups
 
 		// Add the custody group to the map.
 		if !custodyGroupsMap[custodyGroup] {
@@ -88,9 +81,6 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 			// Increment the current ID.
 			currentId.Add(currentId, one)
 		}
-
-		// Sort the custody groups.
-		slices.Sort[[]uint64](custodyGroups)
 	}
 
 	// Final check.
@@ -98,26 +88,29 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 		return nil, errWrongComputedCustodyGroupCount
 	}
 
+	// Sort the custody groups.
+	slices.Sort[[]uint64](custodyGroups)
+
 	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
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#compute_columns_for_custody_group
 func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 	beaconConfig := params.BeaconConfig()
-	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
 
-	if custodyGroup >= numberOfCustodyGroup {
+	if custodyGroup >= numberOfCustodyGroups {
 		return nil, ErrCustodyGroupTooLarge
 	}
 
 	numberOfColumns := beaconConfig.NumberOfColumns
 
-	columnsPerGroup := numberOfColumns / numberOfCustodyGroup
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroups
 
 	columns := make([]uint64, 0, columnsPerGroup)
 	for i := range columnsPerGroup {
-		column := numberOfCustodyGroup*i + custodyGroup
+		column := numberOfCustodyGroups*i + custodyGroup
 		columns = append(columns, column)
 	}
 
@@ -127,7 +120,7 @@ func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 // 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
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block
 func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
 	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
 		return nil, nil
@@ -151,7 +144,7 @@ func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsA
 
 	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
 	if err != nil {
-		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
+		return nil, errors.Wrap(err, "merkle proof KZG commitments")
 	}
 
 	dataColumnSidecars, err := dataColumnsSidecars(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
@@ -176,19 +169,6 @@ func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
 	return columnIndex % numberOfCustodyGroups, 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
@@ -219,6 +199,7 @@ func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
 // 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.)
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars
 func dataColumnsSidecars(
 	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
 	blobKzgCommitments [][]byte,

beacon-chain/core/peerdas/das_core_test.go

@@ -17,8 +17,8 @@ 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)
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroups+1)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupCountTooLarge)
 }
 
@@ -26,8 +26,8 @@ func TestComputeColumnsForCustodyGroup(t *testing.T) {
 	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
 	// --------------------------------------------
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
-	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroup)
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroups)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
 }
 
@@ -104,62 +104,6 @@ func TestComputeCustodyGroupForColumn(t *testing.T) {
 	})
 }
 
-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})

beacon-chain/core/peerdas/info.go

@@ -4,45 +4,17 @@ 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
-	}
-)
+type info struct {
+	CustodyGroups      map[uint64]bool
+	CustodyColumns     map[uint64]bool
+	DataColumnsSubnets map[uint64]bool
+}
 
 const (
 	nodeInfoCacheSize   = 200
@@ -109,61 +81,6 @@ func Info(nodeID enode.ID, custodyGroupCount uint64) (*info, bool, error) {
 	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().SubscribeAllDataSubnets {
-		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().SubscribeAllDataSubnets {
-		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()

beacon-chain/core/peerdas/info_test.go

@@ -4,7 +4,6 @@ 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"
 )
@@ -26,108 +25,3 @@ func TestInfo(t *testing.T) {
 		require.DeepEqual(t, expectedDataColumnsSubnets, actual.DataColumnsSubnets)
 	}
 }
-
-func TestTargetCustodyGroupCount(t *testing.T) {
-	testCases := []struct {
-		name                         string
-		subscribeToAllColumns        bool
-		validatorsCustodyRequirement uint64
-		expected                     uint64
-	}{
-		{
-			name:                         "subscribed to all data subnets",
-			subscribeToAllColumns:        true,
-			validatorsCustodyRequirement: 100,
-			expected:                     128,
-		},
-		{
-			name:                         "no validators attached",
-			subscribeToAllColumns:        false,
-			validatorsCustodyRequirement: 0,
-			expected:                     4,
-		},
-		{
-			name:                         "some validators attached",
-			subscribeToAllColumns:        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.subscribeToAllColumns {
-				resetFlags := flags.Get()
-				gFlags := new(flags.GlobalFlags)
-				gFlags.SubscribeAllDataSubnets = 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
-		subscribeToAllColumns        bool
-		toAdvertiseCustodyGroupCount uint64
-		expected                     uint64
-	}{
-		{
-			name:                         "subscribed to all subnets",
-			subscribeToAllColumns:        true,
-			toAdvertiseCustodyGroupCount: 100,
-			expected:                     128,
-		},
-		{
-			name:                         "higher than custody requirement",
-			subscribeToAllColumns:        false,
-			toAdvertiseCustodyGroupCount: 100,
-			expected:                     100,
-		},
-		{
-			name:                         "lower than custody requirement",
-			subscribeToAllColumns:        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.subscribeToAllColumns {
-				resetFlags := flags.Get()
-				gFlags := new(flags.GlobalFlags)
-				gFlags.SubscribeAllDataSubnets = 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/p2p_interface.go

@@ -10,10 +10,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-const (
-	CustodyGroupCountEnrKey = "cgc"
-	kzgPosition             = 11 // The index of the KZG commitment list in the Body
-)
+const 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")
@@ -27,13 +24,13 @@ var (
 	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
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#custody-group-count
 type Cgc uint64
 
-func (Cgc) ENRKey() string { return CustodyGroupCountEnrKey }
+func (Cgc) ENRKey() string { return params.BeaconNetworkConfig().CustodyGroupCountKey }
 
 // 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
+// https://github.com/ethereum/consensus-specs/blob/master/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
@@ -60,7 +57,7 @@ func VerifyDataColumnSidecar(sidecar blocks.RODataColumn) error {
 // 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
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#verify_data_column_sidecar_kzg_proofs
 func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) error {
 	// Compute the total count.
 	count := 0
@@ -96,7 +93,7 @@ func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) error {
 }
 
 // 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
+// https://github.com/ethereum/consensus-specs/blob/master/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
@@ -128,7 +125,7 @@ func VerifyDataColumnSidecarInclusionProof(sidecar blocks.RODataColumn) error {
 }
 
 // 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
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
 func ComputeSubnetForDataColumnSidecar(columnIndex uint64) uint64 {
 	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
 	return columnIndex % dataColumnSidecarSubnetCount

beacon-chain/core/peerdas/reconstruction.go

@@ -123,7 +123,7 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 
 // ConstructDataColumnSidecars constructs data column sidecars from a block, (un-extended) blobs and
 // cell proofs corresponding the extended blobs. The main purpose of this function is to
-// construct data columns sidecars from data obtained from the execution client via:
+// construct data column sidecars from data obtained from the execution client via:
 // - `engine_getBlobsV2` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getblobsv2, or
 // - `engine_getPayloadV5` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getpayloadv5
 // Note: In this function, to stick with the `BlobsBundleV2` format returned by the execution client in `engine_getPayloadV5`,
@@ -222,8 +222,8 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 	// Check if the data column sidecars are aligned with the block.
 	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(verifiedDataColumnSidecars))
 	for _, verifiedDataColumnSidecar := range verifiedDataColumnSidecars {
-		dataColumnSicecar := verifiedDataColumnSidecar.RODataColumn
-		dataColumnSidecars = append(dataColumnSidecars, dataColumnSicecar)
+		dataColumnSidecar := verifiedDataColumnSidecar.RODataColumn
+		dataColumnSidecars = append(dataColumnSidecars, dataColumnSidecar)
 	}
 
 	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
@@ -241,7 +241,7 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 		return blobSidecars, nil
 	}
 
-	// We need to reconstruct the blobs.
+	// We need to reconstruct the data column sidecars.
 	reconstructedDataColumnSidecars, err := ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
 	if err != nil {
 		return nil, errors.Wrap(err, "reconstruct data column sidecars")

beacon-chain/core/peerdas/reconstruction_test.go

@@ -196,6 +196,26 @@ func TestReconstructBlobs(t *testing.T) {
 		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
 	})
 
+	t.Run("consecutive duplicates", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// [0, 1, 1, 3, 4, ...]
+		verifiedRoSidecars[2] = verifiedRoSidecars[1]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
+	t.Run("non-consecutive duplicates", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// [0, 1, 2, 1, 4, ...]
+		verifiedRoSidecars[3] = verifiedRoSidecars[1]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
 	t.Run("not enough columns", func(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
 

beacon-chain/core/peerdas/validator.go

@@ -8,7 +8,7 @@ import (
 )
 
 // 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
+// https://github.com/ethereum/consensus-specs/blob/master/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 {
@@ -21,10 +21,10 @@ func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validat
 	}
 
 	beaconConfig := params.BeaconConfig()
-	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
 	validatorCustodyRequirement := beaconConfig.ValidatorCustodyRequirement
 	balancePerAdditionalCustodyGroup := beaconConfig.BalancePerAdditionalCustodyGroup
 
 	count := totalNodeBalance / balancePerAdditionalCustodyGroup
-	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroup), nil
+	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroups), nil
 }

beacon-chain/das/BUILD.bazel

@@ -39,10 +39,8 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
-        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification: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",

beacon-chain/das/availability_columns.go

@@ -22,8 +22,8 @@ type LazilyPersistentStoreColumn struct {
 	store                  *filesystem.DataColumnStorage
 	nodeID                 enode.ID
 	cache                  *dataColumnCache
-	custodyInfo            *peerdas.CustodyInfo
 	newDataColumnsVerifier verification.NewDataColumnsVerifier
+	custodyGroupCount      uint64
 }
 
 var _ AvailabilityStore = &LazilyPersistentStoreColumn{}
@@ -38,13 +38,18 @@ type DataColumnsVerifier interface {
 
 // NewLazilyPersistentStoreColumn creates a new LazilyPersistentStoreColumn.
 // WARNING: The resulting LazilyPersistentStoreColumn is NOT thread-safe.
-func NewLazilyPersistentStoreColumn(store *filesystem.DataColumnStorage, nodeID enode.ID, newDataColumnsVerifier verification.NewDataColumnsVerifier, custodyInfo *peerdas.CustodyInfo) *LazilyPersistentStoreColumn {
+func NewLazilyPersistentStoreColumn(
+	store *filesystem.DataColumnStorage,
+	nodeID enode.ID,
+	newDataColumnsVerifier verification.NewDataColumnsVerifier,
+	custodyGroupCount uint64,
+) *LazilyPersistentStoreColumn {
 	return &LazilyPersistentStoreColumn{
 		store:                  store,
 		nodeID:                 nodeID,
 		cache:                  newDataColumnCache(),
-		custodyInfo:            custodyInfo,
 		newDataColumnsVerifier: newDataColumnsVerifier,
+		custodyGroupCount:      custodyGroupCount,
 	}
 }
 
@@ -126,11 +131,11 @@ func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, curre
 		return errors.Wrap(err, "entry filter")
 	}
 
-	// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
 	verifier := s.newDataColumnsVerifier(roDataColumns, verification.ByRangeRequestDataColumnSidecarRequirements)
 
 	if err := verifier.ValidFields(); err != nil {
-		return errors.Wrap(err, "valid")
+		return errors.Wrap(err, "valid fields")
 	}
 
 	if err := verifier.SidecarInclusionProven(); err != nil {
@@ -155,6 +160,8 @@ func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, curre
 
 // fullCommitmentsToCheck returns the commitments to check for a given block.
 func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, block blocks.ROBlock, currentSlot primitives.Slot) (*safeCommitmentsArray, error) {
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+
 	// Return early for blocks that are pre-Fulu.
 	if block.Version() < version.Fulu {
 		return &safeCommitmentsArray{}, nil
@@ -164,7 +171,7 @@ func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, bl
 	blockSlot := block.Block().Slot()
 	blockEpoch := slots.ToEpoch(blockSlot)
 
-	// Compute the current spoch.
+	// Compute the current epoch.
 	currentEpoch := slots.ToEpoch(currentSlot)
 
 	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.
@@ -183,11 +190,9 @@ func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, bl
 		return &safeCommitmentsArray{}, nil
 	}
 
-	// Retrieve the groups count.
-	custodyGroupCount := s.custodyInfo.ActualGroupCount()
-
 	// Retrieve peer info.
-	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	samplingSize := max(s.custodyGroupCount, samplesPerSlot)
+	peerInfo, _, err := peerdas.Info(nodeID, samplingSize)
 	if err != nil {
 		return nil, errors.Wrap(err, "peer info")
 	}

beacon-chain/das/availability_columns_test.go

@@ -4,10 +4,8 @@ import (
 	"context"
 	"testing"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
-	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -29,7 +27,7 @@ var commitments = [][]byte{
 func TestPersist(t *testing.T) {
 	t.Run("no sidecars", func(t *testing.T) {
 		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
 		err := lazilyPersistentStoreColumns.Persist(0)
 		require.NoError(t, err)
 		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
@@ -44,7 +42,7 @@ func TestPersist(t *testing.T) {
 		}
 
 		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
 
 		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
 		require.ErrorIs(t, err, errMixedRoots)
@@ -59,7 +57,7 @@ func TestPersist(t *testing.T) {
 		}
 
 		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
 
 		err := lazilyPersistentStoreColumns.Persist(1_000_000, roSidecars...)
 		require.NoError(t, err)
@@ -76,7 +74,7 @@ func TestPersist(t *testing.T) {
 		}
 
 		roSidecars, roDataColumns := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
 
 		err := lazilyPersistentStoreColumns.Persist(slot, roSidecars...)
 		require.NoError(t, err)
@@ -114,7 +112,7 @@ func TestIsDataAvailable(t *testing.T) {
 		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
 
 		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, 0)
 
 		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
 		require.NoError(t, err)
@@ -135,9 +133,9 @@ func TestIsDataAvailable(t *testing.T) {
 		root := signedRoBlock.Root()
 
 		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, 0)
 
-		indices := [...]uint64{1, 17, 87, 102}
+		indices := [...]uint64{1, 17, 19, 42, 75, 87, 102, 117}
 		dataColumnsParams := make([]util.DataColumnParam, 0, len(indices))
 		for _, index := range indices {
 			dataColumnParams := util.DataColumnParam{
@@ -221,14 +219,10 @@ func TestFullCommitmentsToCheck(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			resetFlags := flags.Get()
-			gFlags := new(flags.GlobalFlags)
-			gFlags.SubscribeAllDataSubnets = true
-			flags.Init(gFlags)
-			defer flags.Init(resetFlags)
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
 
 			b := tc.block(t)
-			s := NewLazilyPersistentStoreColumn(nil, enode.ID{}, nil, &peerdas.CustodyInfo{})
+			s := NewLazilyPersistentStoreColumn(nil, enode.ID{}, nil, numberOfColumns)
 
 			commitmentsArray, err := s.fullCommitmentsToCheck(enode.ID{}, b, tc.slot)
 			require.NoError(t, err)

beacon-chain/db/filesystem/data_column.go

@@ -251,7 +251,7 @@ func (dcs *DataColumnStorage) Summary(root [fieldparams.RootLength]byte) DataCol
 }
 
 // Save saves data column sidecars into the database and asynchronously performs pruning.
-// The returned chanel is closed when the pruning is complete.
+// The returned channel is closed when the pruning is complete.
 func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataColumn) error {
 	startTime := time.Now()
 
@@ -266,8 +266,7 @@ func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataCol
 		return errWrongNumberOfColumns
 	}
 
-	highestEpoch := primitives.Epoch(0)
-	dataColumnSidecarsbyRoot := make(map[[fieldparams.RootLength]byte][]blocks.VerifiedRODataColumn)
+	dataColumnSidecarsByRoot := make(map[[fieldparams.RootLength]byte][]blocks.VerifiedRODataColumn)
 
 	// Group data column sidecars by root.
 	for _, dataColumnSidecar := range dataColumnSidecars {
@@ -278,23 +277,20 @@ func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataCol
 
 		// Group data column sidecars by root.
 		root := dataColumnSidecar.BlockRoot()
-		dataColumnSidecarsbyRoot[root] = append(dataColumnSidecarsbyRoot[root], dataColumnSidecar)
+		dataColumnSidecarsByRoot[root] = append(dataColumnSidecarsByRoot[root], dataColumnSidecar)
 	}
 
-	for root, dataColumnSidecars := range dataColumnSidecarsbyRoot {
+	for root, dataColumnSidecars := range dataColumnSidecarsByRoot {
 		// Safety check all data column sidecars for this root are from the same slot.
-		firstSlot := dataColumnSidecars[0].SignedBlockHeader.Header.Slot
+		slot := dataColumnSidecars[0].Slot()
 		for _, dataColumnSidecar := range dataColumnSidecars[1:] {
-			if dataColumnSidecar.SignedBlockHeader.Header.Slot != firstSlot {
+			if dataColumnSidecar.Slot() != slot {
 				return errDataColumnSidecarsFromDifferentSlots
 			}
 		}
 
-		// Set the highest epoch.
-		epoch := slots.ToEpoch(dataColumnSidecars[0].Slot())
-		highestEpoch = max(highestEpoch, epoch)
-
 		// Save data columns in the filesystem.
+		epoch := slots.ToEpoch(slot)
 		if err := dcs.saveFilesystem(root, epoch, dataColumnSidecars); err != nil {
 			return errors.Wrap(err, "save filesystem")
 		}
@@ -306,7 +302,7 @@ func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataCol
 		}
 
 		// Compute the data columns ident.
-		dataColumnsIdent := DataColumnsIdent{Root: root, Epoch: slots.ToEpoch(dataColumnSidecars[0].Slot()), Indices: indices}
+		dataColumnsIdent := DataColumnsIdent{Root: root, Epoch: epoch, Indices: indices}
 
 		// Set data columns in the cache.
 		if err := dcs.cache.set(dataColumnsIdent); err != nil {

beacon-chain/db/filesystem/doc.go

@@ -20,7 +20,7 @@ File organisation
   The remaining 7 bits (from 0 to 127) represent the index of the data column.
   This sentinel bit is needed to distinguish between the column with index 0 and no column.
   Example: If the column with index 5 is in the 3th position in the file, then indices[5] = 0x80 + 0x03 = 0x83.
-- The rest of the file is a repeat of the SSZ encoded data columns sidecars.
+- The rest of the file is a repeat of the SSZ encoded data column sidecars.
 
 
 |------------------------------------------|------------------------------------------------------------------------------------|
@@ -75,7 +75,7 @@ data-columns
 
 Computation of the maximum size of a DataColumnSidecar
 ------------------------------------------------------
-https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/das-core.md#datacolumnsidecar
+https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#datacolumnsidecar
 
 
 class DataColumnSidecar(Container):

beacon-chain/db/iface/interface.go

@@ -33,6 +33,7 @@ type ReadOnlyDatabase interface {
 	IsFinalizedBlock(ctx context.Context, blockRoot [32]byte) bool
 	FinalizedChildBlock(ctx context.Context, blockRoot [32]byte) (interfaces.ReadOnlySignedBeaconBlock, error)
 	HighestRootsBelowSlot(ctx context.Context, slot primitives.Slot) (primitives.Slot, [][32]byte, error)
+	EarliestSlot(ctx context.Context) (primitives.Slot, error)
 	// State related methods.
 	State(ctx context.Context, blockRoot [32]byte) (state.BeaconState, error)
 	StateOrError(ctx context.Context, blockRoot [32]byte) (state.BeaconState, error)
@@ -56,12 +57,11 @@ type ReadOnlyDatabase interface {
 	// Fee recipients operations.
 	FeeRecipientByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (common.Address, error)
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
-	// light client operations
+	// Light client operations
 	LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]interfaces.LightClientUpdate, error)
 	LightClientUpdate(ctx context.Context, period uint64) (interfaces.LightClientUpdate, error)
 	LightClientBootstrap(ctx context.Context, blockRoot []byte) (interfaces.LightClientBootstrap, error)
-
-	// origin checkpoint sync support
+	// Origin checkpoint sync support
 	OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
 	BackfillStatus(context.Context) (*dbval.BackfillStatus, error)
 }
@@ -102,6 +102,10 @@ type NoHeadAccessDatabase interface {
 
 	CleanUpDirtyStates(ctx context.Context, slotsPerArchivedPoint primitives.Slot) error
 	DeleteHistoricalDataBeforeSlot(ctx context.Context, slot primitives.Slot, batchSize int) (int, error)
+
+	// Custody operations.
+	UpdateSubscribedToAllDataSubnets(ctx context.Context, subscribed bool) (bool, error)
+	UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error)
 }
 
 // HeadAccessDatabase defines a struct with access to reading chain head data.

beacon-chain/db/kv/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "backup.go",
         "blocks.go",
         "checkpoint.go",
+        "custody.go",
         "deposit_contract.go",
         "encoding.go",
         "error.go",
@@ -83,6 +84,7 @@ go_test(
         "backup_test.go",
         "blocks_test.go",
         "checkpoint_test.go",
+        "custody_test.go",
         "deposit_contract_test.go",
         "encoding_test.go",
         "execution_chain_test.go",

beacon-chain/db/kv/blocks.go

@@ -860,6 +860,47 @@ func (s *Store) SaveRegistrationsByValidatorIDs(ctx context.Context, ids []primi
 	})
 }
 
+// EarliestStoredSlot returns the earliest slot in the database.
+func (s *Store) EarliestSlot(ctx context.Context) (primitives.Slot, error) {
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	_, span := trace.StartSpan(ctx, "BeaconDB.EarliestSlot")
+	defer span.End()
+
+	earliestAvailableSlot := primitives.Slot(0)
+	err := s.db.View(func(tx *bolt.Tx) error {
+		// Retrieve the root corresponding to the earliest available block.
+		c := tx.Bucket(blockSlotIndicesBucket).Cursor()
+		k, v := c.First()
+		if k == nil || v == nil {
+			return ErrNotFound
+		}
+		slot := bytesutil.BytesToSlotBigEndian(k)
+
+		// The genesis block may be indexed in this bucket, even if we started from a checkpoint.
+		// Because of this, we check the next block. If the next block is still in the genesis epoch,
+		// then we consider we have the whole chain.
+		if slot != 0 {
+			earliestAvailableSlot = slot
+		}
+
+		k, v = c.Next()
+		if k == nil || v == nil {
+			// Only the genesis block is available.
+			return nil
+		}
+		slot = bytesutil.BytesToSlotBigEndian(k)
+		if slot < slotsPerEpoch {
+			// We are still in the genesis epoch, so we consider we have the whole chain.
+			return nil
+		}
+
+		earliestAvailableSlot = slot
+		return nil
+	})
+
+	return earliestAvailableSlot, err
+}
+
 type slotRoot struct {
 	slot primitives.Slot
 	root [32]byte
@@ -883,7 +924,7 @@ func (s *Store) slotRootsInRange(ctx context.Context, start, end primitives.Slot
 		c := bkt.Cursor()
 		for k, v := c.Seek(key); ; /* rely on internal checks to exit */ k, v = c.Prev() {
 			if len(k) == 0 && len(v) == 0 {
-				// The `edge`` variable and this `if` deal with 2 edge cases:
+				// The `edge` variable and this `if` deal with 2 edge cases:
 				// - Seeking past the end of the bucket (the `end` param is higher than the highest slot).
 				// - Seeking before the beginning of the bucket (the `start` param is lower than the lowest slot).
 				// In both of these cases k,v will be nil and we can handle the same way using `edge` to

beacon-chain/db/kv/blocks_test.go

@@ -1,6 +1,7 @@
 package kv
 
 import (
+	"context"
 	"fmt"
 	"testing"
 	"time"
@@ -1327,3 +1328,86 @@ func TestStore_RegistrationsByValidatorID(t *testing.T) {
 	want := errors.Wrap(ErrNotFoundFeeRecipient, "validator id 3")
 	require.Equal(t, want.Error(), err.Error())
 }
+
+// Block creates a phase0 beacon block at the specified slot and saves it to the database.
+func createAndSaveBlock(t *testing.T, ctx context.Context, db *Store, slot primitives.Slot) {
+	block := util.NewBeaconBlock()
+	block.Block.Slot = slot
+
+	wrappedBlock, err := blocks.NewSignedBeaconBlock(block)
+	require.NoError(t, err)
+	require.NoError(t, db.SaveBlock(ctx, wrappedBlock))
+}
+
+func TestStore_EarliestSlot(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("empty database returns ErrNotFound", func(t *testing.T) {
+		db := setupDB(t)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.ErrorIs(t, err, ErrNotFound)
+		assert.Equal(t, primitives.Slot(0), slot)
+	})
+
+	t.Run("database with only genesis block", func(t *testing.T) {
+		db := setupDB(t)
+
+		// Create and save genesis block (slot 0)
+		createAndSaveBlock(t, ctx, db, 0)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, primitives.Slot(0), slot)
+	})
+
+	t.Run("database with genesis and blocks in genesis epoch", func(t *testing.T) {
+		db := setupDB(t)
+		slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+		// Create and save genesis block (slot 0)
+		createAndSaveBlock(t, ctx, db, 0)
+
+		// Create and save a block in the genesis epoch
+		createAndSaveBlock(t, ctx, db, primitives.Slot(slotsPerEpoch-1))
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, primitives.Slot(0), slot)
+	})
+
+	t.Run("database with genesis and blocks beyond genesis epoch", func(t *testing.T) {
+		db := setupDB(t)
+		slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+		// Create and save genesis block (slot 0)
+		createAndSaveBlock(t, ctx, db, 0)
+
+		// Create and save a block beyond the genesis epoch
+		nextEpochSlot := primitives.Slot(slotsPerEpoch)
+		createAndSaveBlock(t, ctx, db, nextEpochSlot)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, nextEpochSlot, slot)
+	})
+
+	t.Run("database starting from checkpoint (non-zero earliest slot)", func(t *testing.T) {
+		db := setupDB(t)
+		slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+		// Simulate starting from a checkpoint by creating blocks starting from a later slot
+		checkpointSlot := primitives.Slot(slotsPerEpoch * 10) // 10 epochs later
+		nextEpochSlot := checkpointSlot + slotsPerEpoch
+
+		// Create and save first block at checkpoint slot
+		createAndSaveBlock(t, ctx, db, checkpointSlot)
+
+		// Create and save another block in the next epoch
+		createAndSaveBlock(t, ctx, db, nextEpochSlot)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, nextEpochSlot, slot)
+	})
+}

beacon-chain/db/kv/custody.go

@@ -0,0 +1,129 @@
+package kv
+
+import (
+	"context"
+
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	bolt "go.etcd.io/bbolt"
+)
+
+// UpdateCustodyInfo atomically updates the custody group count only it is greater than the stored one.
+// In this case, it also updates the earliest available slot with the provided value.
+// It returns the (potentially updated) custody group count and earliest available slot.
+func (s *Store) UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.UpdateCustodyInfo")
+	defer span.End()
+
+	storedGroupCount, storedEarliestAvailableSlot := uint64(0), primitives.Slot(0)
+	if err := s.db.Update(func(tx *bolt.Tx) error {
+		// Retrieve the custody bucket.
+		bucket, err := tx.CreateBucketIfNotExists(custodyBucket)
+		if err != nil {
+			return errors.Wrap(err, "create custody bucket")
+		}
+
+		// Retrieve the stored custody group count.
+		storedGroupCountBytes := bucket.Get(groupCountKey)
+		if len(storedGroupCountBytes) != 0 {
+			storedGroupCount = bytesutil.BytesToUint64BigEndian(storedGroupCountBytes)
+		}
+
+		// Retrieve the stored earliest available slot.
+		storedEarliestAvailableSlotBytes := bucket.Get(earliestAvailableSlotKey)
+		if len(storedEarliestAvailableSlotBytes) != 0 {
+			storedEarliestAvailableSlot = primitives.Slot(bytesutil.BytesToUint64BigEndian(storedEarliestAvailableSlotBytes))
+		}
+
+		// Exit early if the new custody group count is lower than or equal to the stored one.
+		if custodyGroupCount <= storedGroupCount {
+			return nil
+		}
+
+		storedGroupCount, storedEarliestAvailableSlot = custodyGroupCount, earliestAvailableSlot
+
+		// Store the earliest available slot.
+		bytes := bytesutil.Uint64ToBytesBigEndian(uint64(earliestAvailableSlot))
+		if err := bucket.Put(earliestAvailableSlotKey, bytes); err != nil {
+			return errors.Wrap(err, "put earliest available slot")
+		}
+
+		// Store the custody group count.
+		bytes = bytesutil.Uint64ToBytesBigEndian(custodyGroupCount)
+		if err := bucket.Put(groupCountKey, bytes); err != nil {
+			return errors.Wrap(err, "put custody group count")
+		}
+
+		return nil
+	}); err != nil {
+		return 0, 0, err
+	}
+
+	log.WithFields(logrus.Fields{
+		"earliestAvailableSlot": storedEarliestAvailableSlot,
+		"groupCount":            storedGroupCount,
+	}).Debug("Custody info")
+
+	return storedEarliestAvailableSlot, storedGroupCount, nil
+}
+
+// UpdateSubscribedToAllDataSubnets updates the "subscribed to all data subnets" status in the database
+// only if `subscribed` is `true`.
+// It returns the previous subscription status.
+func (s *Store) UpdateSubscribedToAllDataSubnets(ctx context.Context, subscribed bool) (bool, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.UpdateSubscribedToAllDataSubnets")
+	defer span.End()
+
+	result := false
+	if !subscribed {
+		if err := s.db.View(func(tx *bolt.Tx) error {
+			// Retrieve the custody bucket.
+			bucket := tx.Bucket(custodyBucket)
+			if bucket == nil {
+				return nil
+			}
+
+			// Retrieve the subscribe all data subnets flag.
+			bytes := bucket.Get(subscribeAllDataSubnetsKey)
+			if len(bytes) == 0 {
+				return nil
+			}
+
+			if bytes[0] == 1 {
+				result = true
+			}
+
+			return nil
+		}); err != nil {
+			return false, err
+		}
+
+		return result, nil
+	}
+
+	if err := s.db.Update(func(tx *bolt.Tx) error {
+		// Retrieve the custody bucket.
+		bucket, err := tx.CreateBucketIfNotExists(custodyBucket)
+		if err != nil {
+			return errors.Wrap(err, "create custody bucket")
+		}
+
+		bytes := bucket.Get(subscribeAllDataSubnetsKey)
+		if len(bytes) != 0 && bytes[0] == 1 {
+			result = true
+		}
+
+		if err := bucket.Put(subscribeAllDataSubnetsKey, []byte{1}); err != nil {
+			return errors.Wrap(err, "put subscribe all data subnets")
+		}
+
+		return nil
+	}); err != nil {
+		return false, err
+	}
+
+	return result, nil
+}

beacon-chain/db/kv/custody_test.go

@@ -0,0 +1,176 @@
+package kv
+
+import (
+	"context"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	bolt "go.etcd.io/bbolt"
+)
+
+// getCustodyInfoFromDB reads the custody info directly from the database for testing purposes.
+func getCustodyInfoFromDB(t *testing.T, db *Store) (primitives.Slot, uint64) {
+	t.Helper()
+	var earliestSlot primitives.Slot
+	var groupCount uint64
+
+	err := db.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(custodyBucket)
+		if bucket == nil {
+			return nil
+		}
+
+		// Read group count
+		groupCountBytes := bucket.Get(groupCountKey)
+		if len(groupCountBytes) != 0 {
+			groupCount = bytesutil.BytesToUint64BigEndian(groupCountBytes)
+		}
+
+		// Read earliest available slot
+		earliestSlotBytes := bucket.Get(earliestAvailableSlotKey)
+		if len(earliestSlotBytes) != 0 {
+			earliestSlot = primitives.Slot(bytesutil.BytesToUint64BigEndian(earliestSlotBytes))
+		}
+
+		return nil
+	})
+	require.NoError(t, err)
+
+	return earliestSlot, groupCount
+}
+
+// getSubscriptionStatusFromDB reads the subscription status directly from the database for testing purposes.
+func getSubscriptionStatusFromDB(t *testing.T, db *Store) bool {
+	t.Helper()
+	var subscribed bool
+
+	err := db.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(custodyBucket)
+		if bucket == nil {
+			return nil
+		}
+
+		bytes := bucket.Get(subscribeAllDataSubnetsKey)
+		if len(bytes) != 0 && bytes[0] == 1 {
+			subscribed = true
+		}
+
+		return nil
+	})
+	require.NoError(t, err)
+
+	return subscribed
+}
+
+func TestUpdateCustodyInfo(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("initial update with empty database", func(t *testing.T) {
+		const (
+			earliestSlot = primitives.Slot(100)
+			groupCount   = uint64(5)
+		)
+
+		db := setupDB(t)
+
+		slot, count, err := db.UpdateCustodyInfo(ctx, earliestSlot, groupCount)
+		require.NoError(t, err)
+		require.Equal(t, earliestSlot, slot)
+		require.Equal(t, groupCount, count)
+
+		storedSlot, storedCount := getCustodyInfoFromDB(t, db)
+		require.Equal(t, earliestSlot, storedSlot)
+		require.Equal(t, groupCount, storedCount)
+	})
+
+	t.Run("update with higher group count", func(t *testing.T) {
+		const (
+			initialSlot  = primitives.Slot(100)
+			initialCount = uint64(5)
+			earliestSlot = primitives.Slot(200)
+			groupCount   = uint64(10)
+		)
+
+		db := setupDB(t)
+
+		_, _, err := db.UpdateCustodyInfo(ctx, initialSlot, initialCount)
+		require.NoError(t, err)
+
+		slot, count, err := db.UpdateCustodyInfo(ctx, earliestSlot, groupCount)
+		require.NoError(t, err)
+		require.Equal(t, earliestSlot, slot)
+		require.Equal(t, groupCount, count)
+
+		storedSlot, storedCount := getCustodyInfoFromDB(t, db)
+		require.Equal(t, earliestSlot, storedSlot)
+		require.Equal(t, groupCount, storedCount)
+	})
+
+	t.Run("update with lower group count should not update", func(t *testing.T) {
+		const (
+			initialSlot  = primitives.Slot(200)
+			initialCount = uint64(10)
+			earliestSlot = primitives.Slot(300)
+			groupCount   = uint64(8)
+		)
+
+		db := setupDB(t)
+
+		_, _, err := db.UpdateCustodyInfo(ctx, initialSlot, initialCount)
+		require.NoError(t, err)
+
+		slot, count, err := db.UpdateCustodyInfo(ctx, earliestSlot, groupCount)
+		require.NoError(t, err)
+		require.Equal(t, initialSlot, slot)
+		require.Equal(t, initialCount, count)
+
+		storedSlot, storedCount := getCustodyInfoFromDB(t, db)
+		require.Equal(t, initialSlot, storedSlot)
+		require.Equal(t, initialCount, storedCount)
+	})
+}
+
+func TestUpdateSubscribedToAllDataSubnets(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("initial update with empty database - set to false", func(t *testing.T) {
+		db := setupDB(t)
+
+		prev, err := db.UpdateSubscribedToAllDataSubnets(ctx, false)
+		require.NoError(t, err)
+		require.Equal(t, false, prev)
+
+		stored := getSubscriptionStatusFromDB(t, db)
+		require.Equal(t, false, stored)
+	})
+
+	t.Run("attempt to update from true to false (should not change)", func(t *testing.T) {
+		db := setupDB(t)
+
+		_, err := db.UpdateSubscribedToAllDataSubnets(ctx, true)
+		require.NoError(t, err)
+
+		prev, err := db.UpdateSubscribedToAllDataSubnets(ctx, false)
+		require.NoError(t, err)
+		require.Equal(t, true, prev)
+
+		stored := getSubscriptionStatusFromDB(t, db)
+		require.Equal(t, true, stored)
+	})
+
+	t.Run("attempt to update from true to false (should not change)", func(t *testing.T) {
+		db := setupDB(t)
+
+		_, err := db.UpdateSubscribedToAllDataSubnets(ctx, true)
+		require.NoError(t, err)
+
+		prev, err := db.UpdateSubscribedToAllDataSubnets(ctx, true)
+		require.NoError(t, err)
+		require.Equal(t, true, prev)
+
+		stored := getSubscriptionStatusFromDB(t, db)
+		require.Equal(t, true, stored)
+	})
+}

beacon-chain/db/kv/kv.go

@@ -123,6 +123,7 @@ var Buckets = [][]byte{
 
 	feeRecipientBucket,
 	registrationBucket,
+	custodyBucket,
 }
 
 // KVStoreOption is a functional option that modifies a kv.Store.

beacon-chain/db/kv/schema.go

@@ -70,4 +70,10 @@ var (
 
 	// Migrations
 	migrationsBucket = []byte("migrations")
+
+	// Custody
+	custodyBucket              = []byte("custody")
+	groupCountKey              = []byte("group-count")
+	earliestAvailableSlotKey   = []byte("earliest-available-slot")
+	subscribeAllDataSubnetsKey = []byte("subscribe-all-data-subnets")
 )

beacon-chain/db/kv/wss.go

@@ -43,6 +43,7 @@ func (s *Store) SaveOrigin(ctx context.Context, serState, serBlock []byte) error
 		return errors.Wrap(err, "failed to initialize origin block w/ bytes + config+fork")
 	}
 	blk := wblk.Block()
+	slot := blk.Slot()
 
 	blockRoot, err := blk.HashTreeRoot()
 	if err != nil {
@@ -51,43 +52,43 @@ func (s *Store) SaveOrigin(ctx context.Context, serState, serBlock []byte) error
 
 	pr := blk.ParentRoot()
 	bf := &dbval.BackfillStatus{
-		LowSlot:       uint64(wblk.Block().Slot()),
+		LowSlot:       uint64(slot),
 		LowRoot:       blockRoot[:],
 		LowParentRoot: pr[:],
 		OriginRoot:    blockRoot[:],
-		OriginSlot:    uint64(wblk.Block().Slot()),
+		OriginSlot:    uint64(slot),
 	}
 
 	if err = s.SaveBackfillStatus(ctx, bf); err != nil {
 		return errors.Wrap(err, "unable to save backfill status data to db for checkpoint sync")
 	}
 
-	log.WithField("root", fmt.Sprintf("%#x", blockRoot)).Info("Saving checkpoint block to db")
+	log.WithField("root", fmt.Sprintf("%#x", blockRoot)).Info("Saving checkpoint data into database")
 	if err := s.SaveBlock(ctx, wblk); err != nil {
-		return errors.Wrap(err, "could not save checkpoint block")
+		return errors.Wrap(err, "save block")
 	}
 
 	// save state
-	log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Info("Calling SaveState")
 	if err = s.SaveState(ctx, state, blockRoot); err != nil {
-		return errors.Wrap(err, "could not save state")
+		return errors.Wrap(err, "save state")
 	}
+
 	if err = s.SaveStateSummary(ctx, &ethpb.StateSummary{
 		Slot: state.Slot(),
 		Root: blockRoot[:],
 	}); err != nil {
-		return errors.Wrap(err, "could not save state summary")
+		return errors.Wrap(err, "save state summary")
 	}
 
 	// mark block as head of chain, so that processing will pick up from this point
 	if err = s.SaveHeadBlockRoot(ctx, blockRoot); err != nil {
-		return errors.Wrap(err, "could not save head block root")
+		return errors.Wrap(err, "save head block root")
 	}
 
 	// save origin block root in a special key, to be used when the canonical
 	// origin (start of chain, ie alternative to genesis) block or state is needed
 	if err = s.SaveOriginCheckpointBlockRoot(ctx, blockRoot); err != nil {
-		return errors.Wrap(err, "could not save origin block root")
+		return errors.Wrap(err, "save origin checkpoint block root")
 	}
 
 	// rebuild the checkpoint from the block
@@ -96,15 +97,18 @@ func (s *Store) SaveOrigin(ctx context.Context, serState, serBlock []byte) error
 	if err != nil {
 		return err
 	}
+
 	chkpt := &ethpb.Checkpoint{
 		Epoch: primitives.Epoch(slotEpoch),
 		Root:  blockRoot[:],
 	}
+
 	if err = s.SaveJustifiedCheckpoint(ctx, chkpt); err != nil {
-		return errors.Wrap(err, "could not mark checkpoint sync block as justified")
+		return errors.Wrap(err, "save justified checkpoint")
 	}
+
 	if err = s.SaveFinalizedCheckpoint(ctx, chkpt); err != nil {
-		return errors.Wrap(err, "could not mark checkpoint sync block as finalized")
+		return errors.Wrap(err, "save finalized checkpoint")
 	}
 
 	return nil

beacon-chain/node/BUILD.bazel

@@ -23,7 +23,6 @@ go_library(
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
-        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/db/kv:go_default_library",

beacon-chain/node/node.go

@@ -26,7 +26,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
@@ -124,7 +123,6 @@ type BeaconNode struct {
 	BlobStorageOptions       []filesystem.BlobStorageOption
 	DataColumnStorage        *filesystem.DataColumnStorage
 	DataColumnStorageOptions []filesystem.DataColumnStorageOption
-	custodyInfo              *peerdas.CustodyInfo
 	verifyInitWaiter         *verification.InitializerWaiter
 	syncChecker              *initialsync.SyncChecker
 	slasherEnabled           bool
@@ -166,7 +164,6 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		serviceFlagOpts:         &serviceFlagOpts{},
 		initialSyncComplete:     make(chan struct{}),
 		syncChecker:             &initialsync.SyncChecker{},
-		custodyInfo:             &peerdas.CustodyInfo{},
 		slasherEnabled:          cliCtx.Bool(flags.SlasherFlag.Name),
 	}
 
@@ -236,7 +233,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 	beacon.finalizedStateAtStartUp = nil
 
 	if features.Get().EnableLightClient {
-		beacon.lcStore = lightclient.NewLightClientStore(beacon.db)
+		beacon.lcStore = lightclient.NewLightClientStore(beacon.db, beacon.fetchP2P(), beacon.StateFeed())
 	}
 
 	return beacon, nil
@@ -699,6 +696,7 @@ func (b *BeaconNode) registerP2P(cliCtx *cli.Context) error {
 		Discv5BootStrapAddrs: p2p.ParseBootStrapAddrs(bootstrapNodeAddrs),
 		RelayNodeAddr:        cliCtx.String(cmd.RelayNode.Name),
 		DataDir:              dataDir,
+		DiscoveryDir:         filepath.Join(dataDir, "discovery"),
 		LocalIP:              cliCtx.String(cmd.P2PIP.Name),
 		HostAddress:          cliCtx.String(cmd.P2PHost.Name),
 		HostDNS:              cliCtx.String(cmd.P2PHostDNS.Name),
@@ -716,7 +714,6 @@ func (b *BeaconNode) registerP2P(cliCtx *cli.Context) error {
 		StateNotifier:        b,
 		DB:                   b.db,
 		ClockWaiter:          b.clockWaiter,
-		CustodyInfo:          b.custodyInfo,
 	})
 	if err != nil {
 		return err
@@ -799,7 +796,6 @@ func (b *BeaconNode) registerBlockchainService(fc forkchoice.ForkChoicer, gs *st
 		blockchain.WithTrackedValidatorsCache(b.trackedValidatorsCache),
 		blockchain.WithPayloadIDCache(b.payloadIDCache),
 		blockchain.WithSyncChecker(b.syncChecker),
-		blockchain.WithCustodyInfo(b.custodyInfo),
 		blockchain.WithSlasherEnabled(b.slasherEnabled),
 		blockchain.WithLightClientStore(b.lcStore),
 	)
@@ -887,7 +883,7 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithDataColumnStorage(b.DataColumnStorage),
 		regularsync.WithVerifierWaiter(b.verifyInitWaiter),
 		regularsync.WithAvailableBlocker(bFillStore),
-		regularsync.WithCustodyInfo(b.custodyInfo),
+		regularsync.WithTrackedValidatorsCache(b.trackedValidatorsCache),
 		regularsync.WithSlasherEnabled(b.slasherEnabled),
 		regularsync.WithLightClientStore(b.lcStore),
 		regularsync.WithBatchVerifierLimit(b.cliCtx.Int(flags.BatchVerifierLimit.Name)),

beacon-chain/p2p/BUILD.bazel

@@ -104,6 +104,7 @@ go_library(
         "@com_github_libp2p_go_mplex//:go_default_library",
         "@com_github_multiformats_go_multiaddr//:go_default_library",
         "@com_github_multiformats_go_multiaddr//net:go_default_library",
+        "@com_github_patrickmn_go_cache//: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",
@@ -146,7 +147,6 @@ go_test(
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
@@ -173,7 +173,6 @@ go_test(
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/metadata:go_default_library",
         "//proto/testing:go_default_library",
-        "//runtime/version:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",

beacon-chain/p2p/broadcaster_test.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
-	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
@@ -24,7 +23,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	testpb "github.com/OffchainLabs/prysm/v6/proto/testing"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -229,6 +227,7 @@ func TestService_BroadcastAttestationWithDiscoveryAttempts(t *testing.T) {
 		cfg:                   cfg,
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: genesisValidatorsRoot,
+		custodyInfo:           &custodyInfo{},
 	}
 	bootListener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
@@ -257,6 +256,7 @@ func TestService_BroadcastAttestationWithDiscoveryAttempts(t *testing.T) {
 			cfg:                   cfg,
 			genesisTime:           genesisTime,
 			genesisValidatorsRoot: genesisValidatorsRoot,
+			custodyInfo:           &custodyInfo{},
 		}
 		listener, err := s.startDiscoveryV5(ipAddr, pkey)
 		// Set for 2nd peer
@@ -546,8 +546,7 @@ func TestService_BroadcastLightClientOptimisticUpdate(t *testing.T) {
 		}),
 	}
 
-	l := util.NewTestLightClient(t, version.Altair)
-	msg, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
+	msg, err := util.MockOptimisticUpdate()
 	require.NoError(t, err)
 
 	GossipTypeMapping[reflect.TypeOf(msg)] = LightClientOptimisticUpdateTopicFormat
@@ -613,8 +612,7 @@ func TestService_BroadcastLightClientFinalityUpdate(t *testing.T) {
 		}),
 	}
 
-	l := util.NewTestLightClient(t, version.Altair)
-	msg, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+	msg, err := util.MockFinalityUpdate()
 	require.NoError(t, err)
 
 	GossipTypeMapping[reflect.TypeOf(msg)] = LightClientFinalityUpdateTopicFormat
@@ -699,6 +697,7 @@ func TestService_BroadcastDataColumn(t *testing.T) {
 		subnetsLock:           make(map[uint64]*sync.RWMutex),
 		subnetsLockLock:       sync.Mutex{},
 		peers:                 peers.NewStatus(t.Context(), &peers.StatusConfig{ScorerParams: &scorers.Config{}}),
+		custodyInfo:           &custodyInfo{},
 	}
 
 	// Create a listener.

beacon-chain/p2p/config.go

@@ -4,7 +4,6 @@ import (
 	"time"
 
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 )
@@ -27,6 +26,7 @@ type Config struct {
 	HostDNS              string
 	PrivateKey           string
 	DataDir              string
+	DiscoveryDir         string
 	MetaDataDir          string
 	QUICPort             uint
 	TCPPort              uint
@@ -39,7 +39,6 @@ type Config struct {
 	StateNotifier        statefeed.Notifier
 	DB                   db.ReadOnlyDatabase
 	ClockWaiter          startup.ClockWaiter
-	CustodyInfo          *peerdas.CustodyInfo
 }
 
 // validateConfig validates whether the values provided are accurate and will set

beacon-chain/p2p/custody.go

@@ -3,11 +3,114 @@ package p2p
 import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
-var _ DataColumnsHandler = (*Service)(nil)
+var _ CustodyManager = (*Service)(nil)
+
+// EarliestAvailableSlot returns the earliest available slot.
+func (s *Service) EarliestAvailableSlot() (primitives.Slot, error) {
+	s.custodyInfoLock.RLock()
+	defer s.custodyInfoLock.RUnlock()
+
+	if s.custodyInfo == nil {
+		return 0, errors.New("no custody info available")
+	}
+
+	return s.custodyInfo.earliestAvailableSlot, nil
+}
+
+// CustodyGroupCount returns the custody group count.
+func (s *Service) CustodyGroupCount() (uint64, error) {
+	s.custodyInfoLock.Lock()
+	defer s.custodyInfoLock.Unlock()
+
+	if s.custodyInfo == nil {
+		return 0, errors.New("no custody info available")
+	}
+
+	return s.custodyInfo.groupCount, nil
+}
+
+// UpdateCustodyInfo updates the stored custody group count to the incoming one
+// if the incoming one is greater than the stored one. In this case, the
+// incoming earliest available slot should be greater than or equal to the
+// stored one or an error is returned.
+//
+//   - If there is no stored custody info, or
+//   - If the incoming earliest available slot is greater than or equal to the
+//     fulu fork slot and the incoming custody group count is greater than the
+//     number of samples per slot
+//
+// then the stored earliest available slot is updated to the incoming one.
+//
+// This function returns a boolean indicating whether the custody info was
+// updated and the (possibly updated) custody info itself.
+//
+// Rationale:
+//   - The custody group count can only be increased (specification)
+//   - If the custody group count is increased before Fulu, we can still serve
+//     all the data, since there is no sharding before Fulu. As a consequence
+//     we do not need to update the earliest available slot in this case.
+//   - If the custody group count is increased after Fulu, but to a value less
+//     than or equal to the number of samples per slot, we can still serve all
+//     the data, since we store all sampled data column sidecars in all cases.
+//     As a consequence, we do not need to update the earliest available slot
+//   - If the custody group count is increased after Fulu to a value higher than
+//     the number of samples per slot, then, until the backfill is complete, we
+//     are unable to serve the data column sidecars corresponding to the new
+//     custody groups. As a consequence, we need to update the earliest
+//     available slot to inform the peers that we are not able to serve data
+//     column sidecars before this point.
+func (s *Service) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+
+	s.custodyInfoLock.Lock()
+	defer s.custodyInfoLock.Unlock()
+
+	if s.custodyInfo == nil {
+		s.custodyInfo = &custodyInfo{
+			earliestAvailableSlot: earliestAvailableSlot,
+			groupCount:            custodyGroupCount,
+		}
+		return earliestAvailableSlot, custodyGroupCount, nil
+	}
+
+	inMemory := s.custodyInfo
+	if custodyGroupCount <= inMemory.groupCount {
+		return inMemory.earliestAvailableSlot, inMemory.groupCount, nil
+	}
+
+	if earliestAvailableSlot < inMemory.earliestAvailableSlot {
+		return 0, 0, errors.Errorf(
+			"earliest available slot %d is less than the current one %d. (custody group count: %d, current one: %d)",
+			earliestAvailableSlot, inMemory.earliestAvailableSlot, custodyGroupCount, inMemory.groupCount,
+		)
+	}
+
+	if custodyGroupCount <= samplesPerSlot {
+		inMemory.groupCount = custodyGroupCount
+		return inMemory.earliestAvailableSlot, custodyGroupCount, nil
+	}
+
+	fuluForkSlot, err := fuluForkSlot()
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "fulu fork slot")
+	}
+
+	if earliestAvailableSlot < fuluForkSlot {
+		inMemory.groupCount = custodyGroupCount
+		return inMemory.earliestAvailableSlot, custodyGroupCount, nil
+	}
+
+	inMemory.earliestAvailableSlot = earliestAvailableSlot
+	inMemory.groupCount = custodyGroupCount
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
 
 // CustodyGroupCountFromPeer retrieves custody group count from a peer.
 // It first tries to get the custody group count from the peer's metadata,
@@ -72,3 +175,19 @@ func (s *Service) custodyGroupCountFromPeerENR(pid peer.ID) uint64 {
 
 	return custodyGroupCount
 }
+
+func fuluForkSlot() (primitives.Slot, error) {
+	beaconConfig := params.BeaconConfig()
+
+	fuluForkEpoch := beaconConfig.FuluForkEpoch
+	if fuluForkEpoch == beaconConfig.FarFutureEpoch {
+		return beaconConfig.FarFutureSlot, nil
+	}
+
+	forkFuluSlot, err := slots.EpochStart(fuluForkEpoch)
+	if err != nil {
+		return 0, errors.Wrap(err, "epoch start")
+	}
+
+	return forkFuluSlot, nil
+}

beacon-chain/p2p/custody_test.go

@@ -1,12 +1,15 @@
 package p2p
 
 import (
+	"context"
+	"strings"
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
 	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
@@ -15,6 +18,174 @@ import (
 	"github.com/libp2p/go-libp2p/core/network"
 )
 
+func TestEarliestAvailableSlot(t *testing.T) {
+	t.Run("No custody info available", func(t *testing.T) {
+		service := &Service{
+			custodyInfo: nil,
+		}
+
+		_, err := service.EarliestAvailableSlot()
+
+		require.NotNil(t, err)
+	})
+
+	t.Run("Valid custody info", func(t *testing.T) {
+		const expected primitives.Slot = 100
+
+		service := &Service{
+			custodyInfo: &custodyInfo{
+				earliestAvailableSlot: expected,
+			},
+		}
+
+		slot, err := service.EarliestAvailableSlot()
+
+		require.NoError(t, err)
+		require.Equal(t, expected, slot)
+	})
+}
+
+func TestCustodyGroupCount(t *testing.T) {
+	t.Run("No custody info available", func(t *testing.T) {
+		service := &Service{
+			custodyInfo: nil,
+		}
+
+		_, err := service.CustodyGroupCount()
+
+		require.NotNil(t, err)
+		require.Equal(t, true, strings.Contains(err.Error(), "no custody info available"))
+	})
+
+	t.Run("Valid custody info", func(t *testing.T) {
+		const expected uint64 = 5
+
+		service := &Service{
+			custodyInfo: &custodyInfo{
+				groupCount: expected,
+			},
+		}
+
+		count, err := service.CustodyGroupCount()
+
+		require.NoError(t, err)
+		require.Equal(t, expected, count)
+	})
+}
+
+func TestUpdateCustodyInfo(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.SamplesPerSlot = 8
+	config.FuluForkEpoch = 10
+	params.OverrideBeaconConfig(config)
+
+	testCases := []struct {
+		name               string
+		initialCustodyInfo *custodyInfo
+		inputSlot          primitives.Slot
+		inputGroupCount    uint64
+		expectedUpdated    bool
+		expectedSlot       primitives.Slot
+		expectedGroupCount uint64
+		expectedErr        string
+	}{
+		{
+			name:               "First time setting custody info",
+			initialCustodyInfo: nil,
+			inputSlot:          100,
+			inputGroupCount:    5,
+			expectedUpdated:    true,
+			expectedSlot:       100,
+			expectedGroupCount: 5,
+		},
+		{
+			name: "Group count decrease - no update",
+			initialCustodyInfo: &custodyInfo{
+				earliestAvailableSlot: 50,
+				groupCount:            10,
+			},
+			inputSlot:          60,
+			inputGroupCount:    8,
+			expectedUpdated:    false,
+			expectedSlot:       50,
+			expectedGroupCount: 10,
+		},
+		{
+			name: "Earliest slot decrease - error",
+			initialCustodyInfo: &custodyInfo{
+				earliestAvailableSlot: 100,
+				groupCount:            5,
+			},
+			inputSlot:       50,
+			inputGroupCount: 10,
+			expectedErr:     "earliest available slot 50 is less than the current one 100",
+		},
+		{
+			name: "Group count increase but <= samples per slot",
+			initialCustodyInfo: &custodyInfo{
+				earliestAvailableSlot: 50,
+				groupCount:            5,
+			},
+			inputSlot:          60,
+			inputGroupCount:    8,
+			expectedUpdated:    true,
+			expectedSlot:       50,
+			expectedGroupCount: 8,
+		},
+		{
+			name: "Group count increase > samples per slot, before Fulu fork",
+			initialCustodyInfo: &custodyInfo{
+				earliestAvailableSlot: 50,
+				groupCount:            5,
+			},
+			inputSlot:          60,
+			inputGroupCount:    15,
+			expectedUpdated:    true,
+			expectedSlot:       50,
+			expectedGroupCount: 15,
+		},
+		{
+			name: "Group count increase > samples per slot, after Fulu fork",
+			initialCustodyInfo: &custodyInfo{
+				earliestAvailableSlot: 50,
+				groupCount:            5,
+			},
+			inputSlot:          500,
+			inputGroupCount:    15,
+			expectedUpdated:    true,
+			expectedSlot:       500,
+			expectedGroupCount: 15,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			service := &Service{
+				custodyInfo: tc.initialCustodyInfo,
+			}
+
+			slot, groupCount, err := service.UpdateCustodyInfo(tc.inputSlot, tc.inputGroupCount)
+
+			if tc.expectedErr != "" {
+				require.NotNil(t, err)
+				require.Equal(t, true, strings.Contains(err.Error(), tc.expectedErr))
+				return
+			}
+
+			require.NoError(t, err)
+			require.Equal(t, tc.expectedSlot, slot)
+			require.Equal(t, tc.expectedGroupCount, groupCount)
+
+			if tc.expectedUpdated {
+				require.NotNil(t, service.custodyInfo)
+				require.Equal(t, tc.expectedSlot, service.custodyInfo.earliestAvailableSlot)
+				require.Equal(t, tc.expectedGroupCount, service.custodyInfo.groupCount)
+			}
+		})
+	}
+}
+
 func TestCustodyGroupCountFromPeer(t *testing.T) {
 	const (
 		expectedENR      uint64 = 7
@@ -109,3 +280,59 @@ func TestCustodyGroupCountFromPeer(t *testing.T) {
 	}
 
 }
+
+func TestCustodyGroupCountFromPeerENR(t *testing.T) {
+	const (
+		expectedENR uint64 = 7
+		pid                = "test-id"
+	)
+
+	cgc := peerdas.Cgc(expectedENR)
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+
+	testCases := []struct {
+		name     string
+		record   *enr.Record
+		expected uint64
+		wantErr  bool
+	}{
+		{
+			name:     "No ENR record",
+			record:   nil,
+			expected: custodyRequirement,
+		},
+		{
+			name:     "Empty ENR record",
+			record:   &enr.Record{},
+			expected: custodyRequirement,
+		},
+		{
+			name: "Valid ENR with custody group count",
+			record: func() *enr.Record {
+				record := &enr.Record{}
+				record.Set(cgc)
+				return record
+			}(),
+			expected: expectedENR,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			peers := peers.NewStatus(context.Background(), &peers.StatusConfig{
+				ScorerParams: &scorers.Config{},
+			})
+
+			if tc.record != nil {
+				peers.Add(tc.record, pid, nil, network.DirOutbound)
+			}
+
+			service := &Service{
+				peers: peers,
+			}
+
+			actual := service.custodyGroupCountFromPeerENR(pid)
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}

beacon-chain/p2p/discovery.go

@@ -25,6 +25,7 @@ import (
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/go-bitfield"
+	"github.com/sirupsen/logrus"
 )
 
 type (
@@ -235,22 +236,40 @@ func (s *Service) RefreshPersistentSubnets() {
 	// Get the sync subnet bitfield in our metadata.
 	currentBitSInMetadata := s.Metadata().SyncnetsBitfield()
 
-	// Is our sync bitvector record up to date?
 	isBitSUpToDate := bytes.Equal(bitS, inRecordBitS) && bytes.Equal(bitS, currentBitSInMetadata)
 
 	// Compare current epoch with the Fulu fork epoch.
 	fuluForkEpoch := params.BeaconConfig().FuluForkEpoch
 
+	custodyGroupCount, inRecordCustodyGroupCount := uint64(0), uint64(0)
+	if params.FuluEnabled() {
+		// Get the custody group count we store in our record.
+		inRecordCustodyGroupCount, err = peerdas.CustodyGroupCountFromRecord(record)
+		if err != nil {
+			log.WithError(err).Error("Could not retrieve custody group count")
+			return
+		}
+
+		custodyGroupCount, err = s.CustodyGroupCount()
+		if err != nil {
+			log.WithError(err).Error("Could not retrieve custody group count")
+			return
+		}
+	}
+
 	// We add `1` to the current epoch because we want to prepare one epoch before the Fulu fork.
 	if currentEpoch+1 < fuluForkEpoch {
+		// Is our custody group count record up to date?
+		isCustodyGroupCountUpToDate := custodyGroupCount == inRecordCustodyGroupCount
+
 		// Altair behaviour.
-		if metadataVersion == version.Altair && isBitVUpToDate && isBitSUpToDate {
+		if metadataVersion == version.Altair && isBitVUpToDate && isBitSUpToDate && (!params.FuluEnabled() || isCustodyGroupCountUpToDate) {
 			// Nothing to do, return early.
 			return
 		}
 
 		// Some data have changed, update our record and metadata.
-		s.updateSubnetRecordWithMetadataV2(bitV, bitS)
+		s.updateSubnetRecordWithMetadataV2(bitV, bitS, custodyGroupCount)
 
 		// Ping all peers to inform them of new metadata
 		s.pingPeersAndLogEnr()
@@ -258,16 +277,6 @@ func (s *Service) RefreshPersistentSubnets() {
 		return
 	}
 
-	// Get the current custody group count.
-	custodyGroupCount := s.cfg.CustodyInfo.ActualGroupCount()
-
-	// Get the custody group count we store in our record.
-	inRecordCustodyGroupCount, err := peerdas.CustodyGroupCountFromRecord(record)
-	if err != nil {
-		log.WithError(err).Error("Could not retrieve custody subnet count")
-		return
-	}
-
 	// Get the custody group count in our metadata.
 	inMetadataCustodyGroupCount := s.Metadata().CustodyGroupCount()
 
@@ -544,7 +553,7 @@ func (s *Service) createLocalNode(
 	ipAddr net.IP,
 	udpPort, tcpPort, quicPort int,
 ) (*enode.LocalNode, error) {
-	db, err := enode.OpenDB("")
+	db, err := enode.OpenDB(s.cfg.DiscoveryDir)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not open node's peer database")
 	}
@@ -564,11 +573,6 @@ func (s *Service) createLocalNode(
 		localNode.Set(quicEntry)
 	}
 
-	if params.FuluEnabled() {
-		custodyGroupCount := s.cfg.CustodyInfo.ActualGroupCount()
-		localNode.Set(peerdas.Cgc(custodyGroupCount))
-	}
-
 	localNode.SetFallbackIP(ipAddr)
 	localNode.SetFallbackUDP(udpPort)
 
@@ -580,6 +584,16 @@ func (s *Service) createLocalNode(
 	localNode = initializeAttSubnets(localNode)
 	localNode = initializeSyncCommSubnets(localNode)
 
+	if params.FuluEnabled() {
+		custodyGroupCount, err := s.CustodyGroupCount()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not retrieve custody group count")
+		}
+
+		custodyGroupCountEntry := peerdas.Cgc(custodyGroupCount)
+		localNode.Set(custodyGroupCountEntry)
+	}
+
 	if s.cfg != nil && s.cfg.HostAddress != "" {
 		hostIP := net.ParseIP(s.cfg.HostAddress)
 		if hostIP.To4() == nil && hostIP.To16() == nil {
@@ -603,7 +617,10 @@ func (s *Service) createLocalNode(
 			localNode.SetFallbackIP(firstIP)
 		}
 	}
-
+	log.WithFields(logrus.Fields{
+		"seq": localNode.Seq(),
+		"id":  localNode.ID(),
+	}).Debug("Local node created")
 	return localNode, nil
 }
 
@@ -619,7 +636,11 @@ func (s *Service) startDiscoveryV5(
 		return nil, errors.Wrap(err, "could not create listener")
 	}
 	record := wrappedListener.Self()
-	log.WithField("ENR", record.String()).Info("Started discovery v5")
+
+	log.WithFields(logrus.Fields{
+		"ENR": record.String(),
+		"seq": record.Seq(),
+	}).Info("Started discovery v5")
 	return wrappedListener, nil
 }
 

beacon-chain/p2p/discovery_test.go

@@ -16,7 +16,6 @@ import (
 
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/peerdata"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
@@ -65,6 +64,7 @@ func TestCreateListener(t *testing.T) {
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
 		cfg:                   &Config{UDPPort: uint(port)},
+		custodyInfo:           &custodyInfo{},
 	}
 	listener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
@@ -91,6 +91,7 @@ func TestStartDiscV5_DiscoverAllPeers(t *testing.T) {
 		cfg:                   &Config{UDPPort: uint(port), PingInterval: testPingInterval, DisableLivenessCheck: true},
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: genesisValidatorsRoot,
+		custodyInfo:           &custodyInfo{},
 	}
 	bootListener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
@@ -116,6 +117,7 @@ func TestStartDiscV5_DiscoverAllPeers(t *testing.T) {
 			cfg:                   cfg,
 			genesisTime:           genesisTime,
 			genesisValidatorsRoot: genesisValidatorsRoot,
+			custodyInfo:           &custodyInfo{},
 		}
 		listener, err := s.startDiscoveryV5(ipAddr, pkey)
 		assert.NoError(t, err, "Could not start discovery for node")
@@ -157,27 +159,27 @@ func TestCreateLocalNode(t *testing.T) {
 	}{
 		{
 			name:          "valid config",
-			cfg:           &Config{CustodyInfo: &peerdas.CustodyInfo{}},
+			cfg:           &Config{},
 			expectedError: false,
 		},
 		{
 			name:          "invalid host address",
-			cfg:           &Config{HostAddress: "invalid", CustodyInfo: &peerdas.CustodyInfo{}},
+			cfg:           &Config{HostAddress: "invalid"},
 			expectedError: true,
 		},
 		{
 			name:          "valid host address",
-			cfg:           &Config{HostAddress: "192.168.0.1", CustodyInfo: &peerdas.CustodyInfo{}},
+			cfg:           &Config{HostAddress: "192.168.0.1"},
 			expectedError: false,
 		},
 		{
 			name:          "invalid host DNS",
-			cfg:           &Config{HostDNS: "invalid", CustodyInfo: &peerdas.CustodyInfo{}},
+			cfg:           &Config{HostDNS: "invalid"},
 			expectedError: true,
 		},
 		{
 			name:          "valid host DNS",
-			cfg:           &Config{HostDNS: "www.google.com", CustodyInfo: &peerdas.CustodyInfo{}},
+			cfg:           &Config{HostDNS: "www.google.com"},
 			expectedError: false,
 		},
 	}
@@ -191,6 +193,8 @@ func TestCreateLocalNode(t *testing.T) {
 				quicPort = 3000
 			)
 
+			custodyRequirement := params.BeaconConfig().CustodyRequirement
+
 			// Create a private key.
 			address, privKey := createAddrAndPrivKey(t)
 
@@ -199,6 +203,7 @@ func TestCreateLocalNode(t *testing.T) {
 				genesisTime:           time.Now(),
 				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
 				cfg:                   tt.cfg,
+				custodyInfo:           &custodyInfo{groupCount: custodyRequirement},
 			}
 
 			localNode, err := service.createLocalNode(privKey, address, udpPort, tcpPort, quicPort)
@@ -210,7 +215,7 @@ func TestCreateLocalNode(t *testing.T) {
 			require.NoError(t, err)
 
 			expectedAddress := address
-			if tt.cfg.HostAddress != "" {
+			if tt.cfg != nil && tt.cfg.HostAddress != "" {
 				expectedAddress = net.ParseIP(tt.cfg.HostAddress)
 			}
 
@@ -250,8 +255,8 @@ func TestCreateLocalNode(t *testing.T) {
 
 			// Check cgc config.
 			custodyGroupCount := new(uint64)
-			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(peerdas.CustodyGroupCountEnrKey, custodyGroupCount)))
-			require.Equal(t, params.BeaconConfig().CustodyRequirement, *custodyGroupCount)
+			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(params.BeaconNetworkConfig().CustodyGroupCountKey, custodyGroupCount)))
+			require.Equal(t, custodyRequirement, *custodyGroupCount)
 		})
 	}
 }
@@ -263,7 +268,9 @@ func TestRebootDiscoveryListener(t *testing.T) {
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
 		cfg:                   &Config{UDPPort: uint(port)},
+		custodyInfo:           &custodyInfo{},
 	}
+
 	createListener := func() (*discover.UDPv5, error) {
 		return s.createListener(ipAddr, pkey)
 	}
@@ -293,6 +300,8 @@ func TestMultiAddrsConversion_InvalidIPAddr(t *testing.T) {
 	s := &Service{
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		cfg:                   &Config{},
+		custodyInfo:           &custodyInfo{},
 	}
 	node, err := s.createLocalNode(pkey, addr, 0, 0, 0)
 	require.NoError(t, err)
@@ -311,6 +320,7 @@ func TestMultiAddrConversion_OK(t *testing.T) {
 		},
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		custodyInfo:           &custodyInfo{},
 	}
 	listener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
@@ -384,6 +394,7 @@ func TestHostIsResolved(t *testing.T) {
 		},
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		custodyInfo:           &custodyInfo{},
 	}
 	ip, key := createAddrAndPrivKey(t)
 	list, err := s.createListener(ip, key)
@@ -453,6 +464,7 @@ func TestUDPMultiAddress(t *testing.T) {
 		cfg:                   &Config{UDPPort: uint(port)},
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: genesisValidatorsRoot,
+		custodyInfo:           &custodyInfo{},
 	}
 
 	createListener := func() (*discover.UDPv5, error) {
@@ -495,6 +507,35 @@ func TestMultipleDiscoveryAddresses(t *testing.T) {
 	assert.Equal(t, true, ipv6Found, "IPv6 discovery address not found")
 }
 
+func TestDiscoveryV5_SeqNumber(t *testing.T) {
+	db, err := enode.OpenDB(t.TempDir())
+	require.NoError(t, err)
+	_, key := createAddrAndPrivKey(t)
+	node := enode.NewLocalNode(db, key)
+	node.Set(enr.IPv4{127, 0, 0, 1})
+	currentSeq := node.Seq()
+	s := &Service{dv5Listener: mockListener{localNode: node}}
+	_, err = s.DiscoveryAddresses()
+	require.NoError(t, err)
+	newSeq := node.Seq()
+	require.Equal(t, currentSeq+1, newSeq) // node seq should increase when discovery starts
+
+	// see that the keys changing, will change the node seq
+	_, keyTwo := createAddrAndPrivKey(t)
+	nodeTwo := enode.NewLocalNode(db, keyTwo) // use the same db with different key
+	nodeTwo.Set(enr.IPv6{0x20, 0x01, 0x48, 0x60, 0, 0, 0x20, 0x01, 0, 0, 0, 0, 0, 0, 0x00, 0x68})
+	seqTwo := nodeTwo.Seq()
+	assert.NotEqual(t, seqTwo, newSeq)
+	sTwo := &Service{dv5Listener: mockListener{localNode: nodeTwo}}
+	_, err = sTwo.DiscoveryAddresses()
+	require.NoError(t, err)
+	assert.Equal(t, seqTwo+1, nodeTwo.Seq())
+
+	// see that reloading the same node with same key and db results in same seq number
+	nodeThree := enode.NewLocalNode(db, key)
+	assert.Equal(t, node.Seq(), nodeThree.Seq())
+}
+
 func TestCorrectUDPVersion(t *testing.T) {
 	assert.Equal(t, udp4, udpVersionFromIP(net.IPv4zero), "incorrect network version")
 	assert.Equal(t, udp6, udpVersionFromIP(net.IPv6zero), "incorrect network version")
@@ -624,7 +665,7 @@ func checkPingCountCacheMetadataRecord(
 	if expected.custodyGroupCount != nil {
 		// Check custody subnet count in ENR.
 		var actualCustodyGroupCount uint64
-		err := service.dv5Listener.LocalNode().Node().Record().Load(enr.WithEntry(peerdas.CustodyGroupCountEnrKey, &actualCustodyGroupCount))
+		err := service.dv5Listener.LocalNode().Node().Record().Load(enr.WithEntry(params.BeaconNetworkConfig().CustodyGroupCountKey, &actualCustodyGroupCount))
 		require.NoError(t, err)
 		require.Equal(t, *expected.custodyGroupCount, actualCustodyGroupCount)
 
@@ -787,10 +828,11 @@ func TestRefreshPersistentSubnets(t *testing.T) {
 					actualPingCount++
 					return nil
 				},
-				cfg:                   &Config{UDPPort: 2000, CustodyInfo: &peerdas.CustodyInfo{}},
+				cfg:                   &Config{UDPPort: 2000},
 				peers:                 p2p.Peers(),
 				genesisTime:           time.Now().Add(-time.Duration(tc.epochSinceGenesis*secondsPerEpoch) * time.Second),
 				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+				custodyInfo:           &custodyInfo{groupCount: custodyGroupCount},
 			}
 
 			// Set the listener and the metadata.

beacon-chain/p2p/doc.go

@@ -1,7 +1,7 @@
 /*
 Package p2p implements the Ethereum consensus networking specification.
 
-Canonical spec reference: https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md
+Canonical spec reference: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md
 
 Prysm specific implementation design docs
   - Networking Design Doc: https://docs.google.com/document/d/1VyhobQRkEjEkEPxmmdWvaHfKWn0j6dEae_wLZlrFtfU/view

beacon-chain/p2p/fork_test.go

@@ -40,6 +40,7 @@ func TestStartDiscv5_DifferentForkDigests(t *testing.T) {
 		},
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: genesisValidatorsRoot,
+		custodyInfo:           &custodyInfo{},
 	}
 	bootListener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
@@ -73,6 +74,7 @@ func TestStartDiscv5_DifferentForkDigests(t *testing.T) {
 			cfg:                   cfg,
 			genesisTime:           genesisTime,
 			genesisValidatorsRoot: root,
+			custodyInfo:           &custodyInfo{},
 		}
 		listener, err := s.startDiscoveryV5(ipAddr, pkey)
 		assert.NoError(t, err, "Could not start discovery for node")
@@ -134,6 +136,7 @@ func TestStartDiscv5_SameForkDigests_DifferentNextForkData(t *testing.T) {
 		cfg:                   &Config{UDPPort: uint(port), PingInterval: testPingInterval, DisableLivenessCheck: true},
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: genesisValidatorsRoot,
+		custodyInfo:           &custodyInfo{},
 	}
 	bootListener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
@@ -168,6 +171,7 @@ func TestStartDiscv5_SameForkDigests_DifferentNextForkData(t *testing.T) {
 			cfg:                   cfg,
 			genesisTime:           genesisTime,
 			genesisValidatorsRoot: genesisValidatorsRoot,
+			custodyInfo:           &custodyInfo{},
 		}
 		listener, err := s.startDiscoveryV5(ipAddr, pkey)
 		assert.NoError(t, err, "Could not start discovery for node")

beacon-chain/p2p/handshake.go

@@ -13,6 +13,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/patrickmn/go-cache"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -79,8 +80,8 @@ func (s *Service) disconnectFromPeerOnError(
 // and validating the response from the peer.
 func (s *Service) AddConnectionHandler(reqFunc, goodByeFunc func(ctx context.Context, id peer.ID) error) {
 	// Peer map and lock to keep track of current connection attempts.
+	var peerLock sync.Mutex
 	peerMap := make(map[peer.ID]bool)
-	peerLock := new(sync.Mutex)
 
 	// This is run at the start of each connection attempt, to ensure
 	// that there aren't multiple inflight connection requests for the
@@ -108,6 +109,19 @@ func (s *Service) AddConnectionHandler(reqFunc, goodByeFunc func(ctx context.Con
 	s.host.Network().Notify(&network.NotifyBundle{
 		ConnectedF: func(_ network.Network, conn network.Conn) {
 			remotePeer := conn.RemotePeer()
+			log := log.WithField("peer", remotePeer)
+			direction := conn.Stat().Direction
+
+			// For some reason, right after a disconnection, this `ConnectedF` callback
+			// is called. We want to avoid processing this connection if the peer was
+			// disconnected too recently and if we are at the initiative of this connection.
+			// This is very probably a bug in libp2p.
+			if direction == network.DirOutbound {
+				if err := s.wasDisconnectedTooRecently(remotePeer); err != nil {
+					log.WithError(err).Debug("Skipping connection handler")
+					return
+				}
+			}
 
 			// Connection handler must be non-blocking as part of libp2p design.
 			go func() {
@@ -133,53 +147,56 @@ func (s *Service) AddConnectionHandler(reqFunc, goodByeFunc func(ctx context.Con
 					return
 				}
 
-				// Do not perform handshake on inbound dials.
-				if conn.Stat().Direction == network.DirInbound {
-					_, err := s.peers.ChainState(remotePeer)
-					peerExists := err == nil
-					currentTime := prysmTime.Now()
-
-					// Wait for peer to initiate handshake
-					time.Sleep(timeForStatus)
-
-					// Exit if we are disconnected with the peer.
-					if s.host.Network().Connectedness(remotePeer) != network.Connected {
+				if direction != network.DirInbound {
+					s.peers.SetConnectionState(conn.RemotePeer(), peers.Connecting)
+					if err := reqFunc(context.TODO(), conn.RemotePeer()); err != nil && !errors.Is(err, io.EOF) {
+						s.disconnectFromPeerOnError(conn, goodByeFunc, err)
 						return
 					}
 
-					// If peer hasn't sent a status request, we disconnect with them
-					if _, err := s.peers.ChainState(remotePeer); errors.Is(err, peerdata.ErrPeerUnknown) || errors.Is(err, peerdata.ErrNoPeerStatus) {
-						statusMessageMissing.Inc()
-						s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state"))
-						return
-					}
-
-					if peerExists {
-						updated, err := s.peers.ChainStateLastUpdated(remotePeer)
-						if err != nil {
-							s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state last updated"))
-							return
-						}
-
-						// Exit if we don't receive any current status messages from peer.
-						if updated.IsZero() {
-							s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("is zero"))
-							return
-						}
-
-						if updated.Before(currentTime) {
-							s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("did not update"))
-							return
-						}
-					}
-
 					s.connectToPeer(conn)
 					return
 				}
 
-				s.peers.SetConnectionState(conn.RemotePeer(), peers.Connecting)
-				if err := reqFunc(context.TODO(), conn.RemotePeer()); err != nil && !errors.Is(err, io.EOF) {
-					s.disconnectFromPeerOnError(conn, goodByeFunc, err)
+				// The connection is inbound.
+				_, err = s.peers.ChainState(remotePeer)
+				peerExists := err == nil
+				currentTime := prysmTime.Now()
+
+				// Wait for peer to initiate handshake
+				time.Sleep(timeForStatus)
+
+				// Exit if we are disconnected with the peer.
+				if s.host.Network().Connectedness(remotePeer) != network.Connected {
+					return
+				}
+
+				// If peer hasn't sent a status request, we disconnect with them
+				if _, err := s.peers.ChainState(remotePeer); errors.Is(err, peerdata.ErrPeerUnknown) || errors.Is(err, peerdata.ErrNoPeerStatus) {
+					statusMessageMissing.Inc()
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state"))
+					return
+				}
+
+				if !peerExists {
+					s.connectToPeer(conn)
+					return
+				}
+
+				updated, err := s.peers.ChainStateLastUpdated(remotePeer)
+				if err != nil {
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state last updated"))
+					return
+				}
+
+				// Exit if we don't receive any current status messages from peer.
+				if updated.IsZero() {
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("is zero"))
+					return
+				}
+
+				if updated.Before(currentTime) {
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("did not update"))
 					return
 				}
 
@@ -220,6 +237,12 @@ func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id p
 				}
 
 				s.peers.SetConnectionState(peerID, peers.Disconnected)
+				if err := s.peerDisconnectionTime.Add(peerID.String(), time.Now(), cache.DefaultExpiration); err != nil {
+					// The `DisconnectedF` funcition already called for this peer less than `cache.DefaultExpiration` ago. Skip.
+					// (Very probably a bug in libp2p.)
+					log.WithError(err).Trace("Failed to set peer disconnection time")
+					return
+				}
 
 				// Only log disconnections if we were fully connected.
 				if priorState == peers.Connected {
@@ -231,6 +254,28 @@ func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id p
 	})
 }
 
+// wasDisconnectedTooRecently checks if the peer was disconnected within the last second.
+func (s *Service) wasDisconnectedTooRecently(peerID peer.ID) error {
+	const disconnectionDurationThreshold = 1 * time.Second
+
+	peerDisconnectionTimeObj, ok := s.peerDisconnectionTime.Get(peerID.String())
+	if !ok {
+		return nil
+	}
+
+	peerDisconnectionTime, ok := peerDisconnectionTimeObj.(time.Time)
+	if !ok {
+		return errors.New("invalid peer disconnection time type")
+	}
+
+	timeSinceDisconnection := time.Since(peerDisconnectionTime)
+	if timeSinceDisconnection < disconnectionDurationThreshold {
+		return errors.Errorf("peer %s was disconnected too recently: %s", peerID, timeSinceDisconnection)
+	}
+
+	return nil
+}
+
 func agentString(pid peer.ID, hst host.Host) string {
 	rawVersion, storeErr := hst.Peerstore().Get(pid, agentVersionKey)
 

beacon-chain/p2p/interfaces.go

@@ -7,6 +7,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
 	"github.com/ethereum/go-ethereum/p2p/enode"
@@ -32,13 +33,14 @@ type (
 		ConnectionHandler
 		PeersProvider
 		MetadataProvider
-		DataColumnsHandler
+		CustodyManager
 	}
 
-	// Accessor provides access to the Broadcaster and PeerManager interfaces.
+	// Accessor provides access to the Broadcaster, PeerManager and CustodyManager interfaces.
 	Accessor interface {
 		Broadcaster
 		PeerManager
+		CustodyManager
 	}
 
 	// Broadcaster broadcasts messages to peers over the p2p pubsub protocol.
@@ -118,8 +120,11 @@ type (
 		MetadataSeq() uint64
 	}
 
-	// DataColumnsHandler abstracts some data columns related methods.
-	DataColumnsHandler interface {
+	// CustodyManager abstracts some data columns related methods.
+	CustodyManager interface {
+		EarliestAvailableSlot() (primitives.Slot, error)
+		CustodyGroupCount() (uint64, error)
+		UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error)
 		CustodyGroupCountFromPeer(peer.ID) uint64
 	}
 )

beacon-chain/p2p/peers/peerdata/store.go

@@ -54,7 +54,7 @@ type PeerData struct {
 	NextValidTime time.Time
 	// Chain related data.
 	MetaData                  metadata.Metadata
-	ChainState                *ethpb.Status
+	ChainState                *ethpb.StatusV2
 	ChainStateLastUpdated     time.Time
 	ChainStateValidationError error
 	// Scorers internal data.

beacon-chain/p2p/peers/scorers/bad_responses.go

@@ -101,21 +101,24 @@ func (s *BadResponsesScorer) countNoLock(pid peer.ID) (int, error) {
 
 // Increment increments the number of bad responses we have received from the given remote peer.
 // If peer doesn't exist this method is no-op.
-func (s *BadResponsesScorer) Increment(pid peer.ID) {
+func (s *BadResponsesScorer) Increment(pid peer.ID) int {
 	if pid == "" {
-		return
+		return 0
 	}
+
 	s.store.Lock()
 	defer s.store.Unlock()
 
 	peerData, ok := s.store.PeerData(pid)
-	if !ok {
-		s.store.SetPeerData(pid, &peerdata.PeerData{
-			BadResponses: 1,
-		})
-		return
+	if ok {
+		peerData.BadResponses++
+		return peerData.BadResponses
 	}
-	peerData.BadResponses++
+
+	const badResponses = 1
+	peerData = &peerdata.PeerData{BadResponses: badResponses}
+	s.store.SetPeerData(pid, peerData)
+	return badResponses
 }
 
 // IsBadPeer states if the peer is to be considered bad.

beacon-chain/p2p/peers/scorers/peer_status.go

@@ -112,7 +112,7 @@ func (s *PeerStatusScorer) BadPeers() []peer.ID {
 }
 
 // SetPeerStatus sets chain state data for a given peer.
-func (s *PeerStatusScorer) SetPeerStatus(pid peer.ID, chainState *pb.Status, validationError error) {
+func (s *PeerStatusScorer) SetPeerStatus(pid peer.ID, chainState *pb.StatusV2, validationError error) {
 	s.store.Lock()
 	defer s.store.Unlock()
 
@@ -130,14 +130,14 @@ func (s *PeerStatusScorer) SetPeerStatus(pid peer.ID, chainState *pb.Status, val
 // PeerStatus gets the chain state of the given remote peer.
 // This can return nil if there is no known chain state for the peer.
 // This will error if the peer does not exist.
-func (s *PeerStatusScorer) PeerStatus(pid peer.ID) (*pb.Status, error) {
+func (s *PeerStatusScorer) PeerStatus(pid peer.ID) (*pb.StatusV2, error) {
 	s.store.RLock()
 	defer s.store.RUnlock()
 	return s.peerStatusNoLock(pid)
 }
 
 // peerStatusNoLock lock-free version of PeerStatus.
-func (s *PeerStatusScorer) peerStatusNoLock(pid peer.ID) (*pb.Status, error) {
+func (s *PeerStatusScorer) peerStatusNoLock(pid peer.ID) (*pb.StatusV2, error) {
 	if peerData, ok := s.store.PeerData(pid); ok {
 		if peerData.ChainState == nil {
 			return nil, peerdata.ErrNoPeerStatus

beacon-chain/p2p/peers/scorers/peer_status_test.go

@@ -35,7 +35,7 @@ func TestScorers_PeerStatus_Score(t *testing.T) {
 			name: "existent bad peer",
 			update: func(scorer *scorers.PeerStatusScorer) {
 				scorer.SetHeadSlot(0)
-				scorer.SetPeerStatus("peer1", &pb.Status{
+				scorer.SetPeerStatus("peer1", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: 64,
 				}, p2ptypes.ErrWrongForkDigestVersion)
@@ -48,7 +48,7 @@ func TestScorers_PeerStatus_Score(t *testing.T) {
 			name: "existent peer no head slot for the host node is known",
 			update: func(scorer *scorers.PeerStatusScorer) {
 				scorer.SetHeadSlot(0)
-				scorer.SetPeerStatus("peer1", &pb.Status{
+				scorer.SetPeerStatus("peer1", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: 64,
 				}, nil)
@@ -61,7 +61,7 @@ func TestScorers_PeerStatus_Score(t *testing.T) {
 			name: "existent peer head is before ours",
 			update: func(scorer *scorers.PeerStatusScorer) {
 				scorer.SetHeadSlot(128)
-				scorer.SetPeerStatus("peer1", &pb.Status{
+				scorer.SetPeerStatus("peer1", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: 64,
 				}, nil)
@@ -75,12 +75,12 @@ func TestScorers_PeerStatus_Score(t *testing.T) {
 			update: func(scorer *scorers.PeerStatusScorer) {
 				headSlot := primitives.Slot(128)
 				scorer.SetHeadSlot(headSlot)
-				scorer.SetPeerStatus("peer1", &pb.Status{
+				scorer.SetPeerStatus("peer1", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: headSlot + 64,
 				}, nil)
 				// Set another peer to a higher score.
-				scorer.SetPeerStatus("peer2", &pb.Status{
+				scorer.SetPeerStatus("peer2", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: headSlot + 128,
 				}, nil)
@@ -95,7 +95,7 @@ func TestScorers_PeerStatus_Score(t *testing.T) {
 			update: func(scorer *scorers.PeerStatusScorer) {
 				headSlot := primitives.Slot(128)
 				scorer.SetHeadSlot(headSlot)
-				scorer.SetPeerStatus("peer1", &pb.Status{
+				scorer.SetPeerStatus("peer1", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: headSlot + 64,
 				}, nil)
@@ -108,7 +108,7 @@ func TestScorers_PeerStatus_Score(t *testing.T) {
 			name: "existent peer no max known slot",
 			update: func(scorer *scorers.PeerStatusScorer) {
 				scorer.SetHeadSlot(0)
-				scorer.SetPeerStatus("peer1", &pb.Status{
+				scorer.SetPeerStatus("peer1", &pb.StatusV2{
 					HeadRoot: make([]byte, 32),
 					HeadSlot: 0,
 				}, nil)
@@ -141,7 +141,7 @@ func TestScorers_PeerStatus_IsBadPeer(t *testing.T) {
 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer(pid))
 	assert.NoError(t, peerStatuses.Scorers().PeerStatusScorer().IsBadPeer(pid))
 
-	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid, &pb.Status{}, p2ptypes.ErrWrongForkDigestVersion)
+	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid, &pb.StatusV2{}, p2ptypes.ErrWrongForkDigestVersion)
 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer(pid))
 	assert.NotNil(t, peerStatuses.Scorers().PeerStatusScorer().IsBadPeer(pid))
 }
@@ -160,9 +160,9 @@ func TestScorers_PeerStatus_BadPeers(t *testing.T) {
 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer(pid3))
 	assert.NoError(t, peerStatuses.Scorers().PeerStatusScorer().IsBadPeer(pid3))
 
-	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid1, &pb.Status{}, p2ptypes.ErrWrongForkDigestVersion)
-	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid2, &pb.Status{}, nil)
-	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid3, &pb.Status{}, p2ptypes.ErrWrongForkDigestVersion)
+	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid1, &pb.StatusV2{}, p2ptypes.ErrWrongForkDigestVersion)
+	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid2, &pb.StatusV2{}, nil)
+	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus(pid3, &pb.StatusV2{}, p2ptypes.ErrWrongForkDigestVersion)
 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer(pid1))
 	assert.NotNil(t, peerStatuses.Scorers().PeerStatusScorer().IsBadPeer(pid1))
 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer(pid2))
@@ -179,12 +179,12 @@ func TestScorers_PeerStatus_PeerStatus(t *testing.T) {
 	})
 	status, err := peerStatuses.Scorers().PeerStatusScorer().PeerStatus("peer1")
 	require.ErrorContains(t, peerdata.ErrPeerUnknown.Error(), err)
-	assert.Equal(t, (*pb.Status)(nil), status)
+	assert.Equal(t, (*pb.StatusV2)(nil), status)
 
-	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus("peer1", &pb.Status{
+	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus("peer1", &pb.StatusV2{
 		HeadSlot: 128,
 	}, nil)
-	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus("peer2", &pb.Status{
+	peerStatuses.Scorers().PeerStatusScorer().SetPeerStatus("peer2", &pb.StatusV2{
 		HeadSlot: 128,
 	}, p2ptypes.ErrInvalidEpoch)
 	status, err = peerStatuses.Scorers().PeerStatusScorer().PeerStatus("peer1")

beacon-chain/p2p/peers/status.go

@@ -205,14 +205,14 @@ func (p *Status) ENR(pid peer.ID) (*enr.Record, error) {
 }
 
 // SetChainState sets the chain state of the given remote peer.
-func (p *Status) SetChainState(pid peer.ID, chainState *pb.Status) {
+func (p *Status) SetChainState(pid peer.ID, chainState *pb.StatusV2) {
 	p.scorers.PeerStatusScorer().SetPeerStatus(pid, chainState, nil)
 }
 
 // ChainState gets the chain state of the given remote peer.
 // This will error if the peer does not exist.
 // This will error if there is no known chain state for the peer.
-func (p *Status) ChainState(pid peer.ID) (*pb.Status, error) {
+func (p *Status) ChainState(pid peer.ID) (*pb.StatusV2, error) {
 	return p.scorers.PeerStatusScorer().PeerStatus(pid)
 }
 

beacon-chain/p2p/peers/status_test.go

@@ -289,7 +289,7 @@ func TestPeerChainState(t *testing.T) {
 	require.NoError(t, err)
 
 	finalizedEpoch := primitives.Epoch(123)
-	p.SetChainState(id, &pb.Status{FinalizedEpoch: finalizedEpoch})
+	p.SetChainState(id, &pb.StatusV2{FinalizedEpoch: finalizedEpoch})
 
 	resChainState, err := p.ChainState(id)
 	require.NoError(t, err)
@@ -324,7 +324,7 @@ func TestPeerWithNilChainState(t *testing.T) {
 
 	resChainState, err := p.ChainState(id)
 	require.Equal(t, peerdata.ErrNoPeerStatus, err)
-	var nothing *pb.Status
+	var nothing *pb.StatusV2
 	require.Equal(t, resChainState, nothing)
 }
 
@@ -616,7 +616,7 @@ func TestTrimmedOrderedPeers(t *testing.T) {
 
 	// Peer 1
 	pid1 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid1, &pb.Status{
+	p.SetChainState(pid1, &pb.StatusV2{
 		HeadSlot:       3 * params.BeaconConfig().SlotsPerEpoch,
 		FinalizedEpoch: 3,
 		FinalizedRoot:  mockroot3[:],
@@ -624,7 +624,7 @@ func TestTrimmedOrderedPeers(t *testing.T) {
 
 	// Peer 2
 	pid2 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid2, &pb.Status{
+	p.SetChainState(pid2, &pb.StatusV2{
 		HeadSlot:       4 * params.BeaconConfig().SlotsPerEpoch,
 		FinalizedEpoch: 4,
 		FinalizedRoot:  mockroot4[:],
@@ -632,7 +632,7 @@ func TestTrimmedOrderedPeers(t *testing.T) {
 
 	// Peer 3
 	pid3 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid3, &pb.Status{
+	p.SetChainState(pid3, &pb.StatusV2{
 		HeadSlot:       5 * params.BeaconConfig().SlotsPerEpoch,
 		FinalizedEpoch: 5,
 		FinalizedRoot:  mockroot5[:],
@@ -640,7 +640,7 @@ func TestTrimmedOrderedPeers(t *testing.T) {
 
 	// Peer 4
 	pid4 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid4, &pb.Status{
+	p.SetChainState(pid4, &pb.StatusV2{
 		HeadSlot:       2 * params.BeaconConfig().SlotsPerEpoch,
 		FinalizedEpoch: 2,
 		FinalizedRoot:  mockroot2[:],
@@ -648,7 +648,7 @@ func TestTrimmedOrderedPeers(t *testing.T) {
 
 	// Peer 5
 	pid5 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid5, &pb.Status{
+	p.SetChainState(pid5, &pb.StatusV2{
 		HeadSlot:       2 * params.BeaconConfig().SlotsPerEpoch,
 		FinalizedEpoch: 2,
 		FinalizedRoot:  mockroot2[:],
@@ -1012,7 +1012,7 @@ func TestStatus_BestPeer(t *testing.T) {
 				},
 			})
 			for _, peerConfig := range tt.peers {
-				p.SetChainState(addPeer(t, p, peers.Connected), &pb.Status{
+				p.SetChainState(addPeer(t, p, peers.Connected), &pb.StatusV2{
 					FinalizedEpoch: peerConfig.finalizedEpoch,
 					HeadSlot:       peerConfig.headSlot,
 				})
@@ -1039,7 +1039,7 @@ func TestBestFinalized_returnsMaxValue(t *testing.T) {
 	for i := 0; i <= maxPeers+100; i++ {
 		p.Add(new(enr.Record), peer.ID(rune(i)), nil, network.DirOutbound)
 		p.SetConnectionState(peer.ID(rune(i)), peers.Connected)
-		p.SetChainState(peer.ID(rune(i)), &pb.Status{
+		p.SetChainState(peer.ID(rune(i)), &pb.StatusV2{
 			FinalizedEpoch: 10,
 		})
 	}
@@ -1062,7 +1062,7 @@ func TestStatus_BestNonFinalized(t *testing.T) {
 	for i, headSlot := range peerSlots {
 		p.Add(new(enr.Record), peer.ID(rune(i)), nil, network.DirOutbound)
 		p.SetConnectionState(peer.ID(rune(i)), peers.Connected)
-		p.SetChainState(peer.ID(rune(i)), &pb.Status{
+		p.SetChainState(peer.ID(rune(i)), &pb.StatusV2{
 			HeadSlot: headSlot,
 		})
 	}
@@ -1085,17 +1085,17 @@ func TestStatus_CurrentEpoch(t *testing.T) {
 	})
 	// Peer 1
 	pid1 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid1, &pb.Status{
+	p.SetChainState(pid1, &pb.StatusV2{
 		HeadSlot: params.BeaconConfig().SlotsPerEpoch * 4,
 	})
 	// Peer 2
 	pid2 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid2, &pb.Status{
+	p.SetChainState(pid2, &pb.StatusV2{
 		HeadSlot: params.BeaconConfig().SlotsPerEpoch * 5,
 	})
 	// Peer 3
 	pid3 := addPeer(t, p, peers.Connected)
-	p.SetChainState(pid3, &pb.Status{
+	p.SetChainState(pid3, &pb.StatusV2{
 		HeadSlot: params.BeaconConfig().SlotsPerEpoch * 4,
 	})
 

beacon-chain/p2p/rpc_topic_mappings.go

@@ -108,6 +108,8 @@ const (
 	RPCDataColumnSidecarsByRangeTopicV1 = protocolPrefix + DataColumnSidecarsByRangeName + SchemaVersionV1
 
 	// V2 RPC Topics
+	// RPCStatusTopicV2 defines the v1 topic for the status rpc method.
+	RPCStatusTopicV2 = protocolPrefix + StatusMessageName + SchemaVersionV2
 	// RPCBlocksByRangeTopicV2 defines v2 the topic for the blocks by range rpc method.
 	RPCBlocksByRangeTopicV2 = protocolPrefix + BeaconBlocksByRangeMessageName + SchemaVersionV2
 	// RPCBlocksByRootTopicV2 defines the v2 topic for the blocks by root rpc method.
@@ -130,6 +132,7 @@ var (
 	RPCTopicMappings = map[string]interface{}{
 		// RPC Status Message
 		RPCStatusTopicV1: new(pb.Status),
+		RPCStatusTopicV2: new(pb.StatusV2),
 
 		// RPC Goodbye Message
 		RPCGoodByeTopicV1: new(primitives.SSZUint64),
@@ -201,6 +204,7 @@ var (
 
 	// Maps all the RPC messages which are to updated in fulu.
 	fuluMapping = map[string]string{
+		StatusMessageName:   SchemaVersionV2,
 		MetadataMessageName: SchemaVersionV3,
 	}
 

beacon-chain/p2p/rpc_topic_mappings_test.go

@@ -141,6 +141,11 @@ func TestTopicFromMessage_CorrectType(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, "/eth2/beacon_chain/req/beacon_blocks_by_range/2", topic)
 
+		// Modified in fulu fork.
+		topic, err = TopicFromMessage(StatusMessageName, fuluForkEpoch)
+		require.NoError(t, err)
+		require.Equal(t, "/eth2/beacon_chain/req/status/2", topic)
+
 		// Modified both in altair and fulu fork.
 		topic, err = TopicFromMessage(MetadataMessageName, fuluForkEpoch)
 		require.NoError(t, err)

beacon-chain/p2p/service.go

@@ -16,6 +16,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/types"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	leakybucket "github.com/OffchainLabs/prysm/v6/container/leaky-bucket"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	prysmnetwork "github.com/OffchainLabs/prysm/v6/network"
@@ -31,6 +32,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/libp2p/go-libp2p/core/protocol"
 	"github.com/multiformats/go-multiaddr"
+	"github.com/patrickmn/go-cache"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -61,32 +63,42 @@ var (
 )
 
 // Service for managing peer to peer (p2p) networking.
-type Service struct {
-	started               bool
-	isPreGenesis          bool
-	pingMethod            func(ctx context.Context, id peer.ID) error
-	pingMethodLock        sync.RWMutex
-	cancel                context.CancelFunc
-	cfg                   *Config
-	peers                 *peers.Status
-	addrFilter            *multiaddr.Filters
-	ipLimiter             *leakybucket.Collector
-	privKey               *ecdsa.PrivateKey
-	metaData              metadata.Metadata
-	pubsub                *pubsub.PubSub
-	joinedTopics          map[string]*pubsub.Topic
-	joinedTopicsLock      sync.RWMutex
-	subnetsLock           map[uint64]*sync.RWMutex
-	subnetsLockLock       sync.Mutex // Lock access to subnetsLock
-	initializationLock    sync.Mutex
-	dv5Listener           ListenerRebooter
-	startupErr            error
-	ctx                   context.Context
-	host                  host.Host
-	genesisTime           time.Time
-	genesisValidatorsRoot []byte
-	activeValidatorCount  uint64
-}
+type (
+	Service struct {
+		started               bool
+		isPreGenesis          bool
+		pingMethod            func(ctx context.Context, id peer.ID) error
+		pingMethodLock        sync.RWMutex
+		cancel                context.CancelFunc
+		cfg                   *Config
+		peers                 *peers.Status
+		addrFilter            *multiaddr.Filters
+		ipLimiter             *leakybucket.Collector
+		privKey               *ecdsa.PrivateKey
+		metaData              metadata.Metadata
+		pubsub                *pubsub.PubSub
+		joinedTopics          map[string]*pubsub.Topic
+		joinedTopicsLock      sync.RWMutex
+		subnetsLock           map[uint64]*sync.RWMutex
+		subnetsLockLock       sync.Mutex // Lock access to subnetsLock
+		initializationLock    sync.Mutex
+		dv5Listener           ListenerRebooter
+		startupErr            error
+		ctx                   context.Context
+		host                  host.Host
+		genesisTime           time.Time
+		genesisValidatorsRoot []byte
+		activeValidatorCount  uint64
+		peerDisconnectionTime *cache.Cache
+		custodyInfo           *custodyInfo
+		custodyInfoLock       sync.RWMutex // Lock access to custodyInfo
+	}
+
+	custodyInfo struct {
+		earliestAvailableSlot primitives.Slot
+		groupCount            uint64
+	}
+)
 
 // NewService initializes a new p2p service compatible with shared.Service interface. No
 // connections are made until the Start function is called during the service registry startup.
@@ -115,16 +127,17 @@ func NewService(ctx context.Context, cfg *Config) (*Service, error) {
 	ipLimiter := leakybucket.NewCollector(ipLimit, ipBurst, 30*time.Second, true /* deleteEmptyBuckets */)
 
 	s := &Service{
-		ctx:          ctx,
-		cancel:       cancel,
-		cfg:          cfg,
-		addrFilter:   addrFilter,
-		ipLimiter:    ipLimiter,
-		privKey:      privKey,
-		metaData:     metaData,
-		isPreGenesis: true,
-		joinedTopics: make(map[string]*pubsub.Topic, len(gossipTopicMappings)),
-		subnetsLock:  make(map[uint64]*sync.RWMutex),
+		ctx:                   ctx,
+		cancel:                cancel,
+		cfg:                   cfg,
+		addrFilter:            addrFilter,
+		ipLimiter:             ipLimiter,
+		privKey:               privKey,
+		metaData:              metaData,
+		isPreGenesis:          true,
+		joinedTopics:          make(map[string]*pubsub.Topic, len(gossipTopicMappings)),
+		subnetsLock:           make(map[uint64]*sync.RWMutex),
+		peerDisconnectionTime: cache.New(1*time.Second, 1*time.Minute),
 	}
 
 	ipAddr := prysmnetwork.IPAddr()
@@ -408,7 +421,10 @@ func (s *Service) pingPeersAndLogEnr() {
 	defer s.pingMethodLock.RUnlock()
 
 	localENR := s.dv5Listener.Self()
-	log.WithField("ENR", localENR).Info("New node record")
+	log.WithFields(logrus.Fields{
+		"ENR": localENR,
+		"seq": localENR.Seq(),
+	}).Info("New node record")
 
 	if s.pingMethod == nil {
 		return
@@ -486,14 +502,17 @@ func (s *Service) connectWithPeer(ctx context.Context, info peer.AddrInfo) error
 	if info.ID == s.host.ID() {
 		return nil
 	}
+
 	if err := s.Peers().IsBad(info.ID); err != nil {
-		return errors.Wrap(err, "refused to connect to bad peer")
+		return errors.Wrap(err, "bad peer")
 	}
+
 	ctx, cancel := context.WithTimeout(ctx, maxDialTimeout)
 	defer cancel()
+
 	if err := s.host.Connect(ctx, info); err != nil {
-		s.Peers().Scorers().BadResponsesScorer().Increment(info.ID)
-		return err
+		s.downscorePeer(info.ID, "connectionError")
+		return errors.Wrap(err, "peer connect")
 	}
 	return nil
 }
@@ -524,3 +543,8 @@ func (s *Service) connectToBootnodes() error {
 func (s *Service) isInitialized() bool {
 	return !s.genesisTime.IsZero() && len(s.genesisValidatorsRoot) == 32
 }
+
+func (s *Service) downscorePeer(peerID peer.ID, reason string) {
+	newScore := s.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}

beacon-chain/p2p/service_test.go

@@ -114,6 +114,7 @@ func TestService_Start_OnlyStartsOnce(t *testing.T) {
 	s, err := NewService(t.Context(), cfg)
 	require.NoError(t, err)
 	s.dv5Listener = &mockListener{}
+	s.custodyInfo = &custodyInfo{}
 	exitRoutine := make(chan bool)
 	go func() {
 		s.Start()
@@ -211,6 +212,7 @@ func TestListenForNewNodes(t *testing.T) {
 		cfg:                   cfg,
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: gvr[:],
+		custodyInfo:           &custodyInfo{},
 	}
 
 	bootListener, err := s.createListener(ipAddr, pkey)
@@ -252,6 +254,7 @@ func TestListenForNewNodes(t *testing.T) {
 			cfg:                   cfg,
 			genesisTime:           genesisTime,
 			genesisValidatorsRoot: gvr[:],
+			custodyInfo:           &custodyInfo{},
 		}
 
 		listener, err := s.startDiscoveryV5(ipAddr, pkey)
@@ -281,6 +284,7 @@ func TestListenForNewNodes(t *testing.T) {
 
 	s, err = NewService(t.Context(), cfg)
 	require.NoError(t, err)
+	s.custodyInfo = &custodyInfo{}
 
 	go s.Start()
 
@@ -403,7 +407,7 @@ func TestService_connectWithPeer(t *testing.T) {
 				return ps
 			}(),
 			info:    peer.AddrInfo{ID: "bad"},
-			wantErr: "refused to connect to bad peer",
+			wantErr: "bad peer",
 		},
 	}
 	for _, tt := range tests {

beacon-chain/p2p/subnets.go

@@ -181,6 +181,11 @@ func (s *Service) findPeersWithSubnets(
 		// Get all needed subnets that the node is subscribed to.
 		// Skip nodes that are not subscribed to any of the defective subnets.
 		node := iterator.Node()
+
+		if !s.filterPeer(node) {
+			continue
+		}
+
 		nodeSubnets, err := filter(node)
 		if err != nil {
 			return nil, errors.Wrap(err, "filter node")
@@ -385,11 +390,23 @@ func (s *Service) updateSubnetRecordWithMetadata(bitV bitfield.Bitvector64) {
 // with a new value for a bitfield of subnets tracked. It also record's
 // the sync committee subnet in the enr. It also updates the node's
 // metadata by increasing the sequence number and the subnets tracked by the node.
-func (s *Service) updateSubnetRecordWithMetadataV2(bitVAtt bitfield.Bitvector64, bitVSync bitfield.Bitvector4) {
+func (s *Service) updateSubnetRecordWithMetadataV2(
+	bitVAtt bitfield.Bitvector64,
+	bitVSync bitfield.Bitvector4,
+	custodyGroupCount uint64,
+) {
 	entry := enr.WithEntry(attSubnetEnrKey, &bitVAtt)
 	subEntry := enr.WithEntry(syncCommsSubnetEnrKey, &bitVSync)
-	s.dv5Listener.LocalNode().Set(entry)
-	s.dv5Listener.LocalNode().Set(subEntry)
+
+	localNode := s.dv5Listener.LocalNode()
+	localNode.Set(entry)
+	localNode.Set(subEntry)
+
+	if params.FuluEnabled() {
+		custodyGroupCountEntry := enr.WithEntry(custodyGroupCountEnrKey, custodyGroupCount)
+		localNode.Set(custodyGroupCountEntry)
+	}
+
 	s.metaData = wrapper.WrappedMetadataV1(&pb.MetaDataV1{
 		SeqNumber: s.metaData.SequenceNumber() + 1,
 		Attnets:   bitVAtt,
@@ -416,10 +433,8 @@ func (s *Service) updateSubnetRecordWithMetadataV3(
 	localNode.Set(syncSubnetsEntry)
 	localNode.Set(custodyGroupCountEntry)
 
-	newSeqNumber := s.metaData.SequenceNumber() + 1
-
 	s.metaData = wrapper.WrappedMetadataV2(&pb.MetaDataV2{
-		SeqNumber:         newSeqNumber,
+		SeqNumber:         s.metaData.SequenceNumber() + 1,
 		Attnets:           bitVAtt,
 		Syncnets:          bitVSync,
 		CustodyGroupCount: custodyGroupCount,

beacon-chain/p2p/subnets_test.go

@@ -74,6 +74,7 @@ func TestStartDiscV5_FindAndDialPeersWithSubnet(t *testing.T) {
 		cfg:                   &Config{UDPPort: 2000, TCPPort: 3000, QUICPort: 3000, DisableLivenessCheck: true, PingInterval: testPingInterval},
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: genesisValidatorsRoot,
+		custodyInfo:           &custodyInfo{},
 	}
 
 	bootNodeForkDigest, err := bootNodeService.currentForkDigest()
@@ -108,6 +109,7 @@ func TestStartDiscV5_FindAndDialPeersWithSubnet(t *testing.T) {
 
 		service.genesisTime = genesisTime
 		service.genesisValidatorsRoot = genesisValidatorsRoot
+		service.custodyInfo = &custodyInfo{}
 
 		nodeForkDigest, err := service.currentForkDigest()
 		require.NoError(t, err)
@@ -157,6 +159,7 @@ func TestStartDiscV5_FindAndDialPeersWithSubnet(t *testing.T) {
 
 	service.genesisTime = genesisTime
 	service.genesisValidatorsRoot = genesisValidatorsRoot
+	service.custodyInfo = &custodyInfo{}
 
 	service.Start()
 	defer func() {

beacon-chain/p2p/testing/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing",
     visibility = [
         "//beacon-chain:__subpackages__",
+        "//testing:__subpackages__",
     ],
     deps = [
         "//beacon-chain/core/peerdas:go_default_library",
@@ -24,6 +25,7 @@ go_library(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/primitives: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

@@ -7,6 +7,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
 	"github.com/ethereum/go-ethereum/p2p/enode"
@@ -196,6 +197,22 @@ func (*FakeP2P) InterceptUpgraded(network.Conn) (allow bool, reason control.Disc
 	return true, 0
 }
 
+// EarliestAvailableSlot -- fake.
+func (*FakeP2P) EarliestAvailableSlot() (primitives.Slot, error) {
+	return 0, nil
+}
+
+// CustodyGroupCount -- fake.
+func (*FakeP2P) CustodyGroupCount() (uint64, error) {
+	return 0, nil
+}
+
+// UpdateCustodyInfo -- fake.
+func (s *FakeP2P) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
+// CustodyGroupCountFromPeer -- fake.
 func (*FakeP2P) CustodyGroupCountFromPeer(peer.ID) uint64 {
 	return 0
 }

beacon-chain/p2p/testing/mock_peersprovider.go

@@ -65,7 +65,7 @@ func (m *MockPeersProvider) Peers() *peers.Status {
 		}
 		m.peers.Add(createENR(), id0, ma0, network.DirInbound)
 		m.peers.SetConnectionState(id0, peers.Connected)
-		m.peers.SetChainState(id0, &pb.Status{FinalizedEpoch: 10})
+		m.peers.SetChainState(id0, &pb.StatusV2{FinalizedEpoch: 10})
 		id1, err := peer.Decode(MockRawPeerId1)
 		if err != nil {
 			log.WithError(err).Debug("Cannot decode")
@@ -76,7 +76,7 @@ func (m *MockPeersProvider) Peers() *peers.Status {
 		}
 		m.peers.Add(createENR(), id1, ma1, network.DirOutbound)
 		m.peers.SetConnectionState(id1, peers.Connected)
-		m.peers.SetChainState(id1, &pb.Status{FinalizedEpoch: 11})
+		m.peers.SetChainState(id1, &pb.StatusV2{FinalizedEpoch: 11})
 	}
 	return m.peers
 }

beacon-chain/p2p/testing/p2p.go

@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -17,6 +18,7 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	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"
@@ -48,16 +50,19 @@ const (
 
 // TestP2P represents a p2p implementation that can be used for testing.
 type TestP2P struct {
-	t               *testing.T
-	BHost           host.Host
-	EnodeID         enode.ID
-	pubsub          *pubsub.PubSub
-	joinedTopics    map[string]*pubsub.Topic
-	BroadcastCalled atomic.Bool
-	DelaySend       bool
-	Digest          [4]byte
-	peers           *peers.Status
-	LocalMetadata   metadata.Metadata
+	t                     *testing.T
+	BHost                 host.Host
+	EnodeID               enode.ID
+	pubsub                *pubsub.PubSub
+	joinedTopics          map[string]*pubsub.Topic
+	BroadcastCalled       atomic.Bool
+	DelaySend             bool
+	Digest                [4]byte
+	peers                 *peers.Status
+	LocalMetadata         metadata.Metadata
+	custodyInfoMut        sync.RWMutex // protects custodyGroupCount and earliestAvailableSlot
+	earliestAvailableSlot primitives.Slot
+	custodyGroupCount     uint64
 }
 
 // NewTestP2P initializes a new p2p test service.
@@ -461,6 +466,34 @@ func (*TestP2P) InterceptUpgraded(network.Conn) (allow bool, reason control.Disc
 	return true, 0
 }
 
+// EarliestAvailableSlot .
+func (s *TestP2P) EarliestAvailableSlot() (primitives.Slot, error) {
+	s.custodyInfoMut.RLock()
+	defer s.custodyInfoMut.RUnlock()
+
+	return s.earliestAvailableSlot, nil
+}
+
+// CustodyGroupCount .
+func (s *TestP2P) CustodyGroupCount() (uint64, error) {
+	s.custodyInfoMut.RLock()
+	defer s.custodyInfoMut.RUnlock()
+
+	return s.custodyGroupCount, nil
+}
+
+// UpdateCustodyInfo .
+func (s *TestP2P) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	s.custodyInfoMut.Lock()
+	defer s.custodyInfoMut.Unlock()
+
+	s.earliestAvailableSlot = earliestAvailableSlot
+	s.custodyGroupCount = custodyGroupCount
+
+	return s.earliestAvailableSlot, s.custodyGroupCount, nil
+}
+
+// CustodyGroupCountFromPeer .
 func (s *TestP2P) CustodyGroupCountFromPeer(pid peer.ID) uint64 {
 	// By default, we assume the peer custodies the minimum number of groups.
 	custodyRequirement := params.BeaconConfig().CustodyRequirement

beacon-chain/rpc/endpoints.go

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

beacon-chain/rpc/endpoints_test.go

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

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

@@ -8,6 +8,7 @@ go_library(
         "handlers_state.go",
         "handlers_validator.go",
         "log.go",
+        "metrics.go",
         "server.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/beacon",
@@ -61,6 +62,8 @@ go_library(
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_ethereum_go_ethereum//crypto/kzg4844: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",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -123,6 +126,7 @@ go_test(
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
         "@com_github_stretchr_testify//mock:go_default_library",

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

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/api"
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
@@ -658,6 +659,12 @@ func (s *Server) PublishBlock(w http.ResponseWriter, r *http.Request) {
 // broadcast all given signed blobs. The broadcast behaviour may be adjusted via the
 // `broadcast_validation` query parameter.
 func (s *Server) PublishBlockV2(w http.ResponseWriter, r *http.Request) {
+	start := time.Now()
+	defer func() {
+		duration := time.Since(start).Milliseconds()
+		publishBlockV2Duration.Observe(float64(duration))
+	}()
+
 	ctx, span := trace.StartSpan(r.Context(), "beacon.PublishBlockV2")
 	defer span.End()
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
@@ -1304,7 +1311,7 @@ func (s *Server) GetCommittees(w http.ResponseWriter, r *http.Request) {
 
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 
@@ -1485,7 +1492,7 @@ func (s *Server) GetFinalityCheckpoints(w http.ResponseWriter, r *http.Request)
 	}
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1659,7 +1666,7 @@ func (s *Server) GetPendingConsolidations(w http.ResponseWriter, r *http.Request
 	} 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)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1715,7 +1722,7 @@ func (s *Server) GetPendingDeposits(w http.ResponseWriter, r *http.Request) {
 	} 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)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1771,7 +1778,7 @@ func (s *Server) GetPendingPartialWithdrawals(w http.ResponseWriter, r *http.Req
 	} 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)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1790,6 +1797,63 @@ func (s *Server) GetPendingPartialWithdrawals(w http.ResponseWriter, r *http.Req
 	}
 }
 
+func (s *Server) GetProposerLookahead(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.GetProposerLookahead")
+	defer span.End()
+
+	stateId := r.PathValue("state_id")
+	if stateId == "" {
+		httputil.HandleError(w, "state_id is required in URL params", http.StatusBadRequest)
+		return
+	}
+	st, err := s.Stater.State(ctx, []byte(stateId))
+	if err != nil {
+		shared.WriteStateFetchError(w, err)
+		return
+	}
+	if st.Version() < version.Fulu {
+		httputil.HandleError(w, "state_id is prior to fulu", http.StatusBadRequest)
+		return
+	}
+	pl, err := st.ProposerLookahead()
+	if err != nil {
+		httputil.HandleError(w, "Could not get proposer look ahead: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set(api.VersionHeader, version.String(st.Version()))
+	if httputil.RespondWithSsz(r) {
+		sszLen := (*primitives.ValidatorIndex)(nil).SizeSSZ()
+		sszData := make([]byte, len(pl)*sszLen)
+		for i, idx := range pl {
+			copy(sszData[i*sszLen:(i+1)*sszLen], ssz.MarshalUint64([]byte{}, uint64(idx)))
+		}
+		httputil.WriteSsz(w, sszData)
+	} else {
+		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
+		if err != nil {
+			helpers.HandleIsOptimisticError(w, err)
+			return
+		}
+		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
+		if err != nil {
+			httputil.HandleError(w, "Could not calculate root of latest block header: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		isFinalized := s.FinalizationFetcher.IsFinalized(ctx, blockRoot)
+		vi := make([]string, len(pl))
+		for i, v := range pl {
+			vi[i] = strconv.FormatUint(uint64(v), 10)
+		}
+		resp := structs.GetProposerLookaheadResponse{
+			Version:             version.String(st.Version()),
+			ExecutionOptimistic: isOptimistic,
+			Finalized:           isFinalized,
+			Data:                vi,
+		}
+		httputil.WriteJson(w, resp)
+	}
+}
+
 // SerializeItems serializes a slice of items, each of which implements the MarshalSSZ method,
 // into a single byte array.
 func serializeItems[T interface{ MarshalSSZ() ([]byte, error) }](items []T) ([]byte, error) {

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

@@ -1103,9 +1103,9 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 1, len(msgsInPool))
 		assert.Equal(t, primitives.Slot(1), msgsInPool[0].Slot)
-		assert.Equal(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2", hexutil.Encode(msgsInPool[0].BlockRoot))
+		assert.Equal(t, "0xbacd20f09da907734434f052bd4c9503aa16bab1960e89ea20610d08d064481c", hexutil.Encode(msgsInPool[0].BlockRoot))
 		assert.Equal(t, primitives.ValidatorIndex(1), msgsInPool[0].ValidatorIndex)
-		assert.Equal(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505", hexutil.Encode(msgsInPool[0].Signature))
+		assert.Equal(t, "0xb591bd4ca7d745b6e027879645d7c014fecb8c58631af070f7607acc0c1c948a5102a33267f0e4ba41a85b254b07df91185274375b2e6436e37e81d2fd46cb3751f5a6c86efb7499c1796c0c17e122a54ac067bb0f5ff41f3241659cceb0c21c", hexutil.Encode(msgsInPool[0].Signature))
 		assert.Equal(t, true, broadcaster.BroadcastCalled.Load())
 	})
 	t.Run("multiple", func(t *testing.T) {
@@ -2497,23 +2497,23 @@ var (
 	singleSyncCommitteeMsg = `[
   {
     "slot": "1",
-    "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "beacon_block_root": "0xbacd20f09da907734434f052bd4c9503aa16bab1960e89ea20610d08d064481c",
     "validator_index": "1",
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+    "signature": "0xb591bd4ca7d745b6e027879645d7c014fecb8c58631af070f7607acc0c1c948a5102a33267f0e4ba41a85b254b07df91185274375b2e6436e37e81d2fd46cb3751f5a6c86efb7499c1796c0c17e122a54ac067bb0f5ff41f3241659cceb0c21c"
   }
 ]`
 	multipleSyncCommitteeMsg = `[
   {
     "slot": "1",
-    "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "beacon_block_root": "0xbacd20f09da907734434f052bd4c9503aa16bab1960e89ea20610d08d064481c",
     "validator_index": "1",
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+    "signature": "0xb591bd4ca7d745b6e027879645d7c014fecb8c58631af070f7607acc0c1c948a5102a33267f0e4ba41a85b254b07df91185274375b2e6436e37e81d2fd46cb3751f5a6c86efb7499c1796c0c17e122a54ac067bb0f5ff41f3241659cceb0c21c"
   },
   {
     "slot": "2",
-    "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "beacon_block_root": "0x2757f6fd8590925cd000a86a3e543f98a93eae23781783a33e34504729a8ad0c",
     "validator_index": "1",
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+    "signature": "0x99dfe11b6c8b306d2c72eb891926d37922d226ea8e1e7484d6c30fab746494f192b0daa3e40c13f1e335b35238f3362c113455a329b1fab0bc500bc47f643786f49e151d5b5052afb51af57ba5aa34a6051dc90ee4de83a26eb54a895061d89a"
   }
 ]`
 	// signature is invalid
@@ -2523,6 +2523,18 @@ var (
     "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
     "validator_index": "1",
     "signature": "foo"
+  },
+  {
+	"slot": "1121",
+	"beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+	"validator_index": "1",
+	"signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+  },
+  {
+	"slot": "1121",
+	"beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+	"validator_index": "2",
+	"signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
   }
 ]`
 	// signatures are invalid

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

@@ -56,7 +56,7 @@ func (s *Server) GetStateRoot(w http.ResponseWriter, r *http.Request) {
 	}
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -125,7 +125,7 @@ func (s *Server) GetRandao(w http.ResponseWriter, r *http.Request) {
 
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 
@@ -227,7 +227,7 @@ func (s *Server) GetSyncCommittees(w http.ResponseWriter, r *http.Request) {
 
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 

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

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

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

@@ -44,7 +44,7 @@ func (s *Server) GetValidators(w http.ResponseWriter, r *http.Request) {
 
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -222,7 +222,7 @@ func (s *Server) GetValidator(w http.ResponseWriter, r *http.Request) {
 
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -258,7 +258,7 @@ func (s *Server) GetValidatorBalances(w http.ResponseWriter, r *http.Request) {
 
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -419,7 +419,7 @@ func (s *Server) getValidatorIdentitiesJSON(
 ) {
 	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)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()

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

@@ -0,0 +1,16 @@
+package beacon
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	publishBlockV2Duration = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "publish_block_v2_duration_milliseconds",
+			Help:    "Duration of publishBlockV2 endpoint processing in milliseconds",
+			Buckets: []float64{1, 5, 20, 100, 500, 1000, 2000, 5000},
+		},
+	)
+)

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

@@ -12,6 +12,7 @@ go_library(
         "//network/forks:go_default_library",
         "//network/httputil:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )
 

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

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"math"
 	"net/http"
 	"reflect"
 	"strconv"
@@ -13,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/network/forks"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	log "github.com/sirupsen/logrus"
 )
 
 // GetDepositContract retrieves deposit contract address and genesis fork version.
@@ -80,39 +82,108 @@ func GetSpec(w http.ResponseWriter, r *http.Request) {
 	httputil.WriteJson(w, &structs.GetSpecResponse{Data: data})
 }
 
-func prepareConfigSpec() (map[string]string, error) {
-	data := make(map[string]string)
+func convertValueForJSON(v reflect.Value, tag string) interface{} {
+	// Unwrap pointers / interfaces
+	for v.Kind() == reflect.Interface || v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			return nil
+		}
+		v = v.Elem()
+	}
+
+	switch v.Kind() {
+	// ===== Single byte → 0xAB =====
+	case reflect.Uint8:
+		return hexutil.Encode([]byte{uint8(v.Uint())})
+
+	// ===== Other unsigned numbers → "123" =====
+	case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return strconv.FormatUint(v.Uint(), 10)
+
+	// ===== Signed numbers → "123" =====
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return strconv.FormatInt(v.Int(), 10)
+
+	// ===== Raw bytes – encode to hex =====
+	case reflect.Slice:
+		if v.Type().Elem().Kind() == reflect.Uint8 {
+			return hexutil.Encode(v.Bytes())
+		}
+		fallthrough
+	case reflect.Array:
+		if v.Type().Elem().Kind() == reflect.Uint8 {
+			// Need a copy because v.Slice is illegal on arrays directly
+			tmp := make([]byte, v.Len())
+			reflect.Copy(reflect.ValueOf(tmp), v)
+			return hexutil.Encode(tmp)
+		}
+		// Generic slice/array handling
+		n := v.Len()
+		out := make([]interface{}, n)
+		for i := 0; i < n; i++ {
+			out[i] = convertValueForJSON(v.Index(i), tag)
+		}
+		return out
+
+	// ===== Struct =====
+	case reflect.Struct:
+		t := v.Type()
+		m := make(map[string]interface{}, v.NumField())
+		for i := 0; i < v.NumField(); i++ {
+			f := t.Field(i)
+			if !v.Field(i).CanInterface() {
+				continue // unexported
+			}
+			key := f.Tag.Get("json")
+			if key == "" || key == "-" {
+				key = f.Name
+			}
+			m[key] = convertValueForJSON(v.Field(i), tag)
+		}
+		return m
+
+	// ===== Default =====
+	default:
+		log.WithFields(log.Fields{
+			"fn":   "prepareConfigSpec",
+			"tag":  tag,
+			"kind": v.Kind().String(),
+			"type": v.Type().String(),
+		}).Error("Unsupported config field kind; value forwarded verbatim")
+		return v.Interface()
+	}
+}
+
+func prepareConfigSpec() (map[string]interface{}, error) {
+	data := make(map[string]interface{})
 	config := *params.BeaconConfig()
+
 	t := reflect.TypeOf(config)
 	v := reflect.ValueOf(config)
 
 	for i := 0; i < t.NumField(); i++ {
 		tField := t.Field(i)
-		_, isSpecField := tField.Tag.Lookup("spec")
-		if !isSpecField {
-			// Field should not be returned from API.
+		_, isSpec := tField.Tag.Lookup("spec")
+		if !isSpec {
+			continue
+		}
+		if shouldSkip(tField) {
 			continue
 		}
 
-		tagValue := strings.ToUpper(tField.Tag.Get("yaml"))
-		vField := v.Field(i)
-		switch vField.Kind() {
-		case reflect.Int:
-			data[tagValue] = strconv.FormatInt(vField.Int(), 10)
-		case reflect.Uint64:
-			data[tagValue] = strconv.FormatUint(vField.Uint(), 10)
-		case reflect.Slice:
-			data[tagValue] = hexutil.Encode(vField.Bytes())
-		case reflect.Array:
-			data[tagValue] = hexutil.Encode(reflect.ValueOf(&config).Elem().Field(i).Slice(0, vField.Len()).Bytes())
-		case reflect.String:
-			data[tagValue] = vField.String()
-		case reflect.Uint8:
-			data[tagValue] = hexutil.Encode([]byte{uint8(vField.Uint())})
-		default:
-			return nil, fmt.Errorf("unsupported config field type: %s", vField.Kind().String())
-		}
+		tag := strings.ToUpper(tField.Tag.Get("yaml"))
+		val := v.Field(i)
+		data[tag] = convertValueForJSON(val, tag)
 	}
 
 	return data, nil
 }
+
+func shouldSkip(tField reflect.StructField) bool {
+	// Dynamically skip blob schedule if Fulu is not yet scheduled.
+	if params.BeaconConfig().FuluForkEpoch == math.MaxUint64 &&
+		tField.Type == reflect.TypeOf(params.BeaconConfig().BlobSchedule) {
+		return true
+	}
+	return false
+}

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

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"math"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -200,7 +201,7 @@ func TestGetSpec(t *testing.T) {
 	data, ok := resp.Data.(map[string]interface{})
 	require.Equal(t, true, ok)
 
-	assert.Equal(t, 175, len(data))
+	assert.Equal(t, 176, len(data))
 	for k, v := range data {
 		t.Run(k, func(t *testing.T) {
 			switch k {
@@ -577,6 +578,11 @@ func TestGetSpec(t *testing.T) {
 				assert.Equal(t, "102", v)
 			case "BLOB_SIDECAR_SUBNET_COUNT_ELECTRA":
 				assert.Equal(t, "103", v)
+			case "BLOB_SCHEDULE":
+				// BLOB_SCHEDULE should be an empty slice when no schedule is defined
+				blobSchedule, ok := v.([]interface{})
+				assert.Equal(t, true, ok)
+				assert.Equal(t, 0, len(blobSchedule))
 			default:
 				t.Errorf("Incorrect key: %s", k)
 			}
@@ -637,3 +643,86 @@ func TestForkSchedule_Ok(t *testing.T) {
 		assert.Equal(t, os.Len(), len(resp.Data))
 	})
 }
+
+func TestGetSpec_BlobSchedule(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig().Copy()
+	config.FuluForkEpoch = 1
+
+	// Set up a blob schedule with test data
+	config.BlobSchedule = []params.BlobScheduleEntry{
+		{
+			Epoch:            primitives.Epoch(100),
+			MaxBlobsPerBlock: 6,
+		},
+		{
+			Epoch:            primitives.Epoch(200),
+			MaxBlobsPerBlock: 9,
+		},
+	}
+	params.OverrideBeaconConfig(config)
+
+	request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/config/spec", nil)
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+
+	GetSpec(writer, request)
+	require.Equal(t, http.StatusOK, writer.Code)
+	resp := structs.GetSpecResponse{}
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	data, ok := resp.Data.(map[string]interface{})
+	require.Equal(t, true, ok)
+
+	// Verify BLOB_SCHEDULE is present and properly formatted
+	blobScheduleValue, exists := data["BLOB_SCHEDULE"]
+	require.Equal(t, true, exists)
+
+	// Verify it's a slice of maps (actual JSON object, not string)
+	// The JSON unmarshaling converts it to []interface{} with map[string]interface{} entries
+	blobScheduleSlice, ok := blobScheduleValue.([]interface{})
+	require.Equal(t, true, ok)
+
+	// Convert to generic interface for easier testing
+	var blobSchedule []map[string]interface{}
+	for _, entry := range blobScheduleSlice {
+		entryMap, ok := entry.(map[string]interface{})
+		require.Equal(t, true, ok)
+		blobSchedule = append(blobSchedule, entryMap)
+	}
+
+	// Verify the blob schedule content
+	require.Equal(t, 2, len(blobSchedule))
+
+	// Check first entry - values should be strings for consistent API output
+	assert.Equal(t, "100", blobSchedule[0]["EPOCH"])
+	assert.Equal(t, "6", blobSchedule[0]["MAX_BLOBS_PER_BLOCK"])
+
+	// Check second entry - values should be strings for consistent API output
+	assert.Equal(t, "200", blobSchedule[1]["EPOCH"])
+	assert.Equal(t, "9", blobSchedule[1]["MAX_BLOBS_PER_BLOCK"])
+}
+
+func TestGetSpec_BlobSchedule_NotFulu(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig().Copy()
+	// Fulu not scheduled (default: math.MaxUint64)
+	config.FuluForkEpoch = math.MaxUint64
+	config.BlobSchedule = []params.BlobScheduleEntry{
+		{Epoch: primitives.Epoch(100), MaxBlobsPerBlock: 6},
+	}
+	params.OverrideBeaconConfig(config)
+
+	request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/config/spec", nil)
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+
+	GetSpec(writer, request)
+	require.Equal(t, http.StatusOK, writer.Code)
+	resp := structs.GetSpecResponse{}
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	data, ok := resp.Data.(map[string]interface{})
+	require.Equal(t, true, ok)
+
+	_, exists := data["BLOB_SCHEDULE"]
+	require.Equal(t, false, exists)
+}

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

@@ -46,7 +46,7 @@ func (s *Server) getBeaconStateV2(ctx context.Context, w http.ResponseWriter, id
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, id, s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check if state is optimistic: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()

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

@@ -12,6 +12,7 @@ go_library(
     deps = [
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/db:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
         "//beacon-chain/rpc/lookup:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
@@ -21,6 +22,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//network/httputil:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -40,6 +42,7 @@ go_test(
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
+        "//beacon-chain/rpc/lookup:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
@@ -57,5 +60,6 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/rpc/eth/helpers/sync.go

@@ -3,15 +3,18 @@ package helpers
 import (
 	"bytes"
 	"context"
+	"net/http"
 	"strconv"
 	"strings"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/lookup"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
@@ -127,7 +130,7 @@ func isStateRootOptimistic(
 ) (bool, error) {
 	st, err := stateFetcher.State(ctx, stateId)
 	if err != nil {
-		return true, errors.Wrap(err, "could not fetch state")
+		return true, lookup.NewFetchStateError(err)
 	}
 	if st.Slot() == chainInfo.HeadSlot() {
 		return optimisticModeFetcher.IsOptimistic(ctx)
@@ -152,3 +155,14 @@ func isStateRootOptimistic(
 	// No block matching requested state root, return true.
 	return true, nil
 }
+
+// HandleIsOptimisticError adds more fine grained handling of the IsOptimistic function's error and sets the error in the response writer
+func HandleIsOptimisticError(w http.ResponseWriter, err error) {
+	var fetchErr *lookup.FetchStateError
+	if errors.As(err, &fetchErr) {
+		shared.WriteStateFetchError(w, err)
+		return
+	}
+	httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+	return
+}

beacon-chain/rpc/eth/helpers/sync_test.go

@@ -1,12 +1,15 @@
 package helpers
 
 import (
+	"net/http"
+	"net/http/httptest"
 	"strconv"
 	"testing"
 
 	chainmock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/lookup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/testutil"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
@@ -21,6 +24,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
 )
 
 func TestIsOptimistic(t *testing.T) {
@@ -226,6 +230,25 @@ func TestIsOptimistic(t *testing.T) {
 			require.NoError(t, err)
 			assert.Equal(t, true, o)
 		})
+		t.Run("State not found", func(t *testing.T) {
+			b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+			require.NoError(t, err)
+			b.SetStateRoot(bytesutil.PadTo([]byte("root"), 32))
+			db := dbtest.SetupDB(t)
+			require.NoError(t, db.SaveBlock(ctx, b))
+			chainSt, err := util.NewBeaconState()
+			require.NoError(t, err)
+			require.NoError(t, chainSt.SetSlot(fieldparams.SlotsPerEpoch))
+			bRoot, err := b.Block().HashTreeRoot()
+			require.NoError(t, err)
+			cs := &chainmock.ChainService{State: chainSt, OptimisticRoots: map[[32]byte]bool{bRoot: true}}
+			mf := &testutil.MockStater{
+				CustomError: lookup.NewFetchStateError(nil),
+			}
+			_, err = IsOptimistic(ctx, []byte(hexutil.Encode(bytesutil.PadTo([]byte("root"), 32))), cs, mf, cs, db)
+			var fetchErr *lookup.FetchStateError
+			require.Equal(t, true, errors.As(err, &fetchErr))
+		})
 	})
 	t.Run("slot", func(t *testing.T) {
 		t.Run("head is not optimistic", func(t *testing.T) {
@@ -370,3 +393,25 @@ func prepareForkchoiceState(
 	roblock, err := blocks.NewROBlockWithRoot(signed, blockRoot)
 	return st, roblock, err
 }
+
+func TestHandleIsOptimisticError(t *testing.T) {
+	t.Run("fetch-state error handled as 404", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		notFoundErr := lookup.StateNotFoundError{}
+		fetchErr := lookup.NewFetchStateError(&notFoundErr)
+		HandleIsOptimisticError(rr, fetchErr)
+
+		require.Equal(t, http.StatusNotFound, rr.Code)
+		require.StringContains(t, notFoundErr.Error(), rr.Body.String())
+	})
+
+	t.Run("generic error handled as 500", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		genericErr := errors.New("boom")
+
+		HandleIsOptimisticError(rr, genericErr)
+
+		require.Equal(t, http.StatusInternalServerError, rr.Code)
+		require.StringContains(t, "Could not check optimistic status: boom", rr.Body.String())
+	})
+}

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

@@ -33,9 +33,11 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//api/server/structs:go_default_library",
+        "//async/event:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

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

@@ -11,9 +11,11 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
+	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	dbtesting "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	p2ptesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -53,7 +55,7 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 			require.NoError(t, err)
 
 			db := dbtesting.SetupDB(t)
-			lcStore := lightclient.NewLightClientStore(db)
+			lcStore := lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed))
 
 			err = db.SaveLightClientBootstrap(l.Ctx, blockRoot[:], bootstrap)
 			require.NoError(t, err)
@@ -97,7 +99,7 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 			require.NoError(t, err)
 
 			db := dbtesting.SetupDB(t)
-			lcStore := lightclient.NewLightClientStore(db)
+			lcStore := lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed))
 
 			err = db.SaveLightClientBootstrap(l.Ctx, blockRoot[:], bootstrap)
 			require.NoError(t, err)
@@ -141,7 +143,7 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 
 	t.Run("no bootstrap found", func(t *testing.T) {
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t)),
+			LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 		request := httptest.NewRequest("GET", "http://foo.com/", nil)
 		request.SetPathValue("block_root", hexutil.Encode([]byte{0x00, 0x01, 0x02}))
@@ -184,7 +186,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 				}
 
 				s := &Server{
-					LCStore: lightclient.NewLightClientStore(db),
+					LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 				}
 
 				updatePeriod := startPeriod
@@ -325,7 +327,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 
 				db := dbtesting.SetupDB(t)
 				s := &Server{
-					LCStore: lightclient.NewLightClientStore(db),
+					LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 				}
 
 				updates := make([]interfaces.LightClientUpdate, 2)
@@ -445,7 +447,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 
 		db := dbtesting.SetupDB(t)
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(db),
+			LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 
 		updates := make([]interfaces.LightClientUpdate, 3)
@@ -492,7 +494,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 
 		db := dbtesting.SetupDB(t)
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(db),
+			LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 
 		updates := make([]interfaces.LightClientUpdate, 3)
@@ -536,7 +538,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 	t.Run("start period before altair", func(t *testing.T) {
 		db := dbtesting.SetupDB(t)
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(db),
+			LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 		startPeriod := 0
 		url := fmt.Sprintf("http://foo.com/?count=128&start_period=%d", startPeriod)
@@ -559,7 +561,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		t.Run("missing update in the middle", func(t *testing.T) {
 			db := dbtesting.SetupDB(t)
 			s := &Server{
-				LCStore: lightclient.NewLightClientStore(db),
+				LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 			}
 
 			updates := make([]interfaces.LightClientUpdate, 3)
@@ -603,7 +605,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		t.Run("missing update at the beginning", func(t *testing.T) {
 			db := dbtesting.SetupDB(t)
 			s := &Server{
-				LCStore: lightclient.NewLightClientStore(db),
+				LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 			}
 
 			updates := make([]interfaces.LightClientUpdate, 3)
@@ -663,8 +665,8 @@ func TestLightClientHandler_GetLightClientFinalityUpdate(t *testing.T) {
 			update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastFinalityUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastFinalityUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			writer := httptest.NewRecorder()
@@ -688,8 +690,8 @@ func TestLightClientHandler_GetLightClientFinalityUpdate(t *testing.T) {
 			update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastFinalityUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastFinalityUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			request.Header.Add("Accept", "application/octet-stream")
@@ -727,7 +729,7 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 	helpers.ClearCache()
 
 	t.Run("no update", func(t *testing.T) {
-		s := &Server{LCStore: &lightclient.Store{}}
+		s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
 
 		request := httptest.NewRequest("GET", "http://foo.com", nil)
 		writer := httptest.NewRecorder()
@@ -743,8 +745,8 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 			update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastOptimisticUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastOptimisticUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			writer := httptest.NewRecorder()
@@ -767,8 +769,8 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 			update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastOptimisticUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastOptimisticUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			request.Header.Add("Accept", "application/octet-stream")

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

@@ -19,12 +19,14 @@ go_library(
         "//beacon-chain/p2p/peers/peerdata:go_default_library",
         "//beacon-chain/rpc/eth/shared:go_default_library",
         "//beacon-chain/sync:go_default_library",
+        "//config/params:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/migration:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -47,6 +49,7 @@ go_test(
         "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/sync/initial-sync/testing:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
         "//network/httputil:go_default_library",

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

@@ -9,10 +9,12 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/eth/v1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
@@ -75,17 +77,25 @@ func (s *Server) GetIdentity(w http.ResponseWriter, r *http.Request) {
 		httputil.HandleError(w, "Could not obtain enr: "+err.Error(), http.StatusInternalServerError)
 		return
 	}
-
+	currentEpoch := slots.ToEpoch(s.GenesisTimeFetcher.CurrentSlot())
+	metadata := s.MetadataProvider.Metadata()
+	md := &structs.Metadata{
+		SeqNumber: strconv.FormatUint(s.MetadataProvider.MetadataSeq(), 10),
+		Attnets:   hexutil.Encode(metadata.AttnetsBitfield()),
+	}
+	if currentEpoch >= params.BeaconConfig().AltairForkEpoch {
+		md.Syncnets = hexutil.Encode(metadata.SyncnetsBitfield())
+	}
+	if currentEpoch >= params.BeaconConfig().FuluForkEpoch {
+		md.Cgc = strconv.FormatUint(metadata.CustodyGroupCount(), 10)
+	}
 	resp := &structs.GetIdentityResponse{
 		Data: &structs.Identity{
 			PeerId:             peerId,
 			Enr:                "enr:" + serializedEnr,
 			P2PAddresses:       p2pAddresses,
 			DiscoveryAddresses: discoveryAddresses,
-			Metadata: &structs.Metadata{
-				SeqNumber: strconv.FormatUint(s.MetadataProvider.MetadataSeq(), 10),
-				Attnets:   hexutil.Encode(s.MetadataProvider.Metadata().AttnetsBitfield()),
-			},
+			Metadata:           md,
 		},
 	}
 	httputil.WriteJson(w, resp)

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

@@ -15,6 +15,7 @@ import (
 	mockp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/testutil"
 	syncmock "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
@@ -144,7 +145,14 @@ func TestGetIdentity(t *testing.T) {
 	require.NoError(t, err)
 	attnets := bitfield.NewBitvector64()
 	attnets.SetBitAt(1, true)
-	metadataProvider := &mockp2p.MockMetadataProvider{Data: wrapper.WrappedMetadataV0(&pb.MetaDataV0{SeqNumber: 1, Attnets: attnets})}
+	syncnets := bitfield.NewBitvector4()
+	syncnets.SetBitAt(1, true)
+	metadataProvider := &mockp2p.MockMetadataProvider{Data: wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		SeqNumber:         1,
+		Attnets:           attnets,
+		Syncnets:          syncnets,
+		CustodyGroupCount: 2,
+	})}
 
 	t.Run("OK", func(t *testing.T) {
 		peerManager := &mockp2p.MockPeerManager{
@@ -154,8 +162,9 @@ func TestGetIdentity(t *testing.T) {
 			DiscoveryAddr: []ma.Multiaddr{discAddr1, discAddr2},
 		}
 		s := &Server{
-			PeerManager:      peerManager,
-			MetadataProvider: metadataProvider,
+			PeerManager:        peerManager,
+			MetadataProvider:   metadataProvider,
+			GenesisTimeFetcher: &mock.ChainService{},
 		}
 
 		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/node/identity", nil)
@@ -187,6 +196,33 @@ func TestGetIdentity(t *testing.T) {
 		assert.Equal(t, discAddr1.String(), resp.Data.DiscoveryAddresses[0])
 		assert.Equal(t, discAddr2.String(), resp.Data.DiscoveryAddresses[1])
 	})
+	t.Run("OK Fulu", func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig()
+		cfg.FuluForkEpoch = 0
+		params.OverrideBeaconConfig(cfg)
+		peerManager := &mockp2p.MockPeerManager{
+			Enr:           enrRecord,
+			PID:           "foo",
+			BHost:         &mockp2p.MockHost{Addresses: []ma.Multiaddr{p2pAddr}},
+			DiscoveryAddr: []ma.Multiaddr{discAddr1, discAddr2},
+		}
+		s := &Server{
+			PeerManager:        peerManager,
+			MetadataProvider:   metadataProvider,
+			GenesisTimeFetcher: &mock.ChainService{},
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/node/identity", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetIdentity(writer, request)
+		require.Equal(t, http.StatusOK, writer.Code)
+		resp := &structs.GetIdentityResponse{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		require.Equal(t, "2", resp.Data.Metadata.Cgc)
+	})
 
 	t.Run("ENR failure", func(t *testing.T) {
 		peerManager := &mockp2p.MockPeerManager{

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

@@ -118,8 +118,9 @@ func (s *Server) produceBlockV3(ctx context.Context, w http.ResponseWriter, r *h
 	consensusBlockValue, httpError := getConsensusBlockValue(ctx, s.BlockRewardFetcher, v1alpha1resp.Block)
 	if httpError != nil {
 		log.WithError(httpError).Debug("Failed to get consensus block value")
-		// Having the consensus block value is not critical to block production
-		consensusBlockValue = ""
+		// Having the consensus block value is not critical to block production.
+		// We set it to zero to satisfy the specification, which requires a numeric value.
+		consensusBlockValue = "0"
 	}
 
 	w.Header().Set(api.ExecutionPayloadBlindedHeader, fmt.Sprintf("%v", v1alpha1resp.IsBlinded))

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

@@ -15,6 +15,7 @@ import (
 	rewardtesting "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/rewards/testing"
 	rpctesting "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared/testing"
 	mockSync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
+	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	mock2 "github.com/OffchainLabs/prysm/v6/testing/mock"
@@ -408,6 +409,82 @@ func TestProduceBlockV3(t *testing.T) {
 		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
 		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
 	})
+	t.Run("Fulu", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsFulu
+		err := json.Unmarshal([]byte(rpctesting.FuluBlockContents), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.ToUnsigned())
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"fulu","execution_payload_blinded":false,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
+	t.Run("Blinded Fulu", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockFulu
+		err := json.Unmarshal([]byte(rpctesting.BlindedFuluBlock), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.Message)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.Message.ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"fulu","execution_payload_blinded":true,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "true", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 	t.Run("invalid query parameter slot empty", func(t *testing.T) {
 		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
 		server := &Server{
@@ -461,6 +538,46 @@ func TestProduceBlockV3(t *testing.T) {
 		assert.Equal(t, http.StatusServiceUnavailable, writer.Code)
 		assert.Equal(t, true, strings.Contains(writer.Body.String(), "Beacon node is currently syncing and not serving request on that endpoint"))
 	})
+	t.Run("0 block value is returned on error", func(t *testing.T) {
+		rewardFetcher := &rewardtesting.MockBlockRewardFetcher{Error: &httputil.DefaultJsonError{}}
+
+		var block *structs.SignedBeaconBlockContentsFulu
+		err := json.Unmarshal([]byte(rpctesting.FuluBlockContents), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.ToUnsigned())
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"fulu","execution_payload_blinded":false,"execution_payload_value":"2000","consensus_block_value":"0","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "0", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 }
 
 func TestProduceBlockV3SSZ(t *testing.T) {
@@ -960,4 +1077,47 @@ func TestProduceBlockV3SSZ(t *testing.T) {
 		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
 		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
 	})
+	t.Run("0 block value is returned on error", func(t *testing.T) {
+		rewardFetcher := &rewardtesting.MockBlockRewardFetcher{Error: &httputil.DefaultJsonError{}}
+
+		var block *structs.SignedBeaconBlockContentsFulu
+		err := json.Unmarshal([]byte(rpctesting.FuluBlockContents), &block)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		g, err := block.ToUnsigned().ToGeneric()
+		require.NoError(t, err)
+		bl, ok := g.Block.(*eth.GenericBeaconBlock_Fulu)
+		require.Equal(t, true, ok)
+		ssz, err := bl.Fulu.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, string(ssz), writer.Body.String())
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "0", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 }