SSZ-QL: custom Generic Merkle Proofs building the tree and collecting the hashes in one sweep (#16177)

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**What type of PR is this?**
Feature

**What does this PR do? Why is it needed?**
This PR replaces the previous PR
https://github.com/OffchainLabs/prysm/pull/16121, which built the entire
Merkle tree and generated proofs only after the tree was complete. In
this PR, the Merkle proof is produced by collecting hashes while the
Merkle tree is being built. This approach has proven to be more
efficient than the one in
https://github.com/OffchainLabs/prysm/pull/16121.

- **ProofCollector**: 
- New `ProofCollector` type in `encoding/ssz/query/proof_collector.go`:
Collects sibling hashes and leaves needed for Merkle proofs during
merkleization.
- Multiproof-ready design with `requiredSiblings`/`requiredLeaves` maps
for registering target gindices before merkleization.
- Thread-safe: read-only required maps during merkleization,
mutex-protected writes to `siblings`/`leaves`.
- `AddTarget(gindex)` registers a target leaf and computes all required
sibling gindices along the path to root.
- `toProof()` converts collected data into `fastssz.Proof` structure.
- Parallel execution in `merkleizeVectorBody` for composite elements
with worker pool pattern.
- Optimized container hashing: Generalized
`stateutil.OptimizedValidatorRoots` pattern for any SSZ container type:
- `optimizedContainerRoots`: Parallelized field root computation +
level-by-level vectorized hashing via `VectorizedSha256`.
- `hashContainerHelper`: Worker goroutine for processing container
subsets.
- `containerFieldRoots`: Computes field roots for a single container
using reflection and SszInfo metadata.

- **`Prove(gindex)` method** in `encoding/ssz/query/merkle_proof.go`:
Entry point for generating SSZ Merkle proofs for a given generalized
index.

- **Testing**
- Added `merkle_proof_test.go` and `proof_collector_test.go` to test and
benchmark this feature.

The main outcomes of the optimizations are here:
```
❯ go test ./encoding/ssz/query -run=^$ -bench='Benchmark(OptimizedContainerRoots|OptimizedValidatorRoots|ProofCollectorMerkleize)$' -benchmem
goos: darwin
goarch: arm64
pkg: github.com/OffchainLabs/prysm/v7/encoding/ssz/query
cpu: Apple M2 Pro
BenchmarkOptimizedValidatorRoots-10         3237            361029 ns/op          956858 B/op       6024 allocs/op
BenchmarkOptimizedContainerRoots-10         1138            969002 ns/op         3245223 B/op      11024 allocs/op
BenchmarkProofCollectorMerkleize-10          522           2262066 ns/op         3216000 B/op      19000 allocs/op
PASS
ok      github.com/OffchainLabs/prysm/v7/encoding/ssz/query     4.619s
```
Knowing that `OptimizedValidatorRoots` implements very effective
optimizations, `OptimizedContainerRoots` mimics them.
In the benchmark we can see that `OptimizedValidatorRoots` remain as the
most performant and tit the baseline here:
- `ProofCollectorMerkleize` is **~6.3× slower**, uses **~3.4× more
memory** (B/op), and performs **~3.2× more allocations**.
- `OptimizedContainerRoots` sits in between: it’s **~2.7× slower** than
`OptimizedValidatorRoots` (and **~3.4× higher B/op**, **~1.8× more
allocations**), but it is a clear win over `ProofCollectorMerkleize` for
lists/vectors: **~2.3× faster** with **~1.7× fewer allocations** (and
essentially the same memory footprint).

The main drawback is that `OptimizedContainerRoots` can only be applied
to vector/list subtrees where we don’t need to collect any sibling/leaf
data (i.e., no proof targets within that subtree); integrating it into
the recursive merkleize(...) flow when targets are outside the subtree
is expected to land in a follow-up PR.

**Which issues(s) does this PR fix?**
Partially https://github.com/OffchainLabs/prysm/issues/15598

**Other notes for review**
In this [write-up](https://hackmd.io/@fernantho/BJbZ1xmmbg), I depict
the process to come up with this solution.

Future improvements:
- Defensive check that the gindex is not too big, depicted [here](
https://github.com/OffchainLabs/prysm/pull/16177#discussion_r2671684100).
- Integrate optimizedContainerRoots into the recursive merkleize(...)
flow when proof targets are not within the subtree (skip full traversal
for container lists).
- Add multiproofs.
- Connect `proofCollector` to SSZ-QL endpoints (direct integration of
`proofCollector` for BeaconBlock endpoint and "hybrid" approach for
BeaconState endpoint).

**Acknowledgements**

- [x] I have read
[CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
- [x] I have included a uniquely named [changelog fragment
file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
- [x] I have added a description with sufficient context for reviewers
to understand this PR.
- [x] I have tested that my changes work as expected and I added a
testing plan to the PR description (if applicable).

---------

Co-authored-by: Radosław Kapka <radoslaw.kapka@gmail.com>
Co-authored-by: Jun Song <87601811+syjn99@users.noreply.github.com>

beacon-chain/db/kv/error.go

@@ -22,6 +22,10 @@ var ErrNotFoundFeeRecipient = errors.Wrap(ErrNotFound, "fee recipient")
 // ErrNotFoundMetadataSeqNum is a not found error specifically for the metadata sequence number getter
 var ErrNotFoundMetadataSeqNum = errors.Wrap(ErrNotFound, "metadata sequence number")
 
+// ErrStateDiffIncompatible is returned when state-diff feature is enabled
+// but the database was created without state-diff support.
+var ErrStateDiffIncompatible = errors.New("state-diff feature enabled but database was created without state-diff support")
+
 var errEmptyBlockSlice = errors.New("[]blocks.ROBlock is empty")
 var errIncorrectBlockParent = errors.New("unexpected missing or forked blocks in a []ROBlock")
 var errFinalizedChildNotFound = errors.New("unable to find finalized root descending from backfill batch")

beacon-chain/db/kv/genesis.go

@@ -42,6 +42,10 @@ func (s *Store) SaveGenesisData(ctx context.Context, genesisState state.BeaconSt
 	if err := s.SaveGenesisBlockRoot(ctx, genesisBlkRoot); err != nil {
 		return errors.Wrap(err, "could not save genesis block root")
 	}
+
+	if err := s.initializeStateDiff(0, genesisState); err != nil {
+		return errors.Wrap(err, "failed to initialize state diff for genesis")
+	}
 	return nil
 }
 

beacon-chain/db/kv/kv.go

@@ -203,15 +203,45 @@ func NewKVStore(ctx context.Context, dirPath string, opts ...KVStoreOption) (*St
 		return nil, err
 	}
 
-	if features.Get().EnableStateDiff {
-		sdCache, err := newStateDiffCache(kv)
-		if err != nil {
-			return nil, err
+	if err := kv.startStateDiff(ctx); err != nil {
+		if errors.Is(err, ErrStateDiffIncompatible) {
+			return kv, err
 		}
-		kv.stateDiffCache = sdCache
+		return nil, err
+	}
+	return kv, nil
+}
+
+func (kv *Store) startStateDiff(ctx context.Context) error {
+	if !features.Get().EnableStateDiff {
+		return nil
+	}
+	// Check if offset already exists (existing state-diff database).
+	hasOffset, err := kv.hasStateDiffOffset()
+	if err != nil {
+		return err
 	}
 
-	return kv, nil
+	if hasOffset {
+		// Existing state-diff database - restarts not yet supported.
+		return errors.New("restarting with existing state-diff database not yet supported")
+	}
+
+	// Check if this is a new database (no head block).
+	headBlock, err := kv.HeadBlock(ctx)
+	if err != nil {
+		return errors.Wrap(err, "could not get head block")
+	}
+
+	if headBlock == nil {
+		// New database - will be initialized later during checkpoint/genesis sync.
+		// stateDiffCache stays nil until SaveOrigin or SaveGenesisData initializes it.
+		log.Info("State-diff enabled: will be initialized during checkpoint or genesis sync")
+	} else {
+		// Existing database without state-diff - return store with error for caller to handle.
+		return ErrStateDiffIncompatible
+	}
+	return nil
 }
 
 // ClearDB removes the previously stored database in the data directory.

beacon-chain/db/kv/state_diff_helpers.go

@@ -9,11 +9,13 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state"
 	statenative "github.com/OffchainLabs/prysm/v7/beacon-chain/state/state-native"
 	"github.com/OffchainLabs/prysm/v7/cmd/beacon-chain/flags"
+	"github.com/OffchainLabs/prysm/v7/config/features"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/hdiff"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v7/math"
 	ethpb "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v7/runtime/version"
+	pkgerrors "github.com/pkg/errors"
 	"go.etcd.io/bbolt"
 )
 
@@ -122,6 +124,66 @@ func (s *Store) getOffset() uint64 {
 	return s.stateDiffCache.getOffset()
 }
 
+// hasStateDiffOffset checks if the state-diff offset has been set in the database.
+// This is used to detect if an existing database has state-diff enabled.
+func (s *Store) hasStateDiffOffset() (bool, error) {
+	var hasOffset bool
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		bucket := tx.Bucket(stateDiffBucket)
+		if bucket == nil {
+			return nil
+		}
+		hasOffset = bucket.Get(offsetKey) != nil
+		return nil
+	})
+	return hasOffset, err
+}
+
+// initializeStateDiff sets up the state-diff schema for a new database.
+// This should be called during checkpoint sync or genesis sync.
+func (s *Store) initializeStateDiff(slot primitives.Slot, initialState state.ReadOnlyBeaconState) error {
+	// Return early if the feature is not set
+	if !features.Get().EnableStateDiff {
+		return nil
+	}
+	// Only reinitialize if the offset is different
+	if s.stateDiffCache != nil {
+		if s.stateDiffCache.getOffset() == uint64(slot) {
+			log.WithField("offset", slot).Warning("Ignoring state diff cache reinitialization")
+			return nil
+		}
+	}
+	// Write offset directly to the database (without using cache which doesn't exist yet).
+	err := s.db.Update(func(tx *bbolt.Tx) error {
+		bucket := tx.Bucket(stateDiffBucket)
+		if bucket == nil {
+			return bbolt.ErrBucketNotFound
+		}
+
+		offsetBytes := make([]byte, 8)
+		binary.LittleEndian.PutUint64(offsetBytes, uint64(slot))
+		return bucket.Put(offsetKey, offsetBytes)
+	})
+	if err != nil {
+		return pkgerrors.Wrap(err, "failed to set offset")
+	}
+
+	// Create the state diff cache (this will read the offset from the database).
+	sdCache, err := newStateDiffCache(s)
+	if err != nil {
+		return pkgerrors.Wrap(err, "failed to create state diff cache")
+	}
+	s.stateDiffCache = sdCache
+
+	// Save the initial state as a full snapshot.
+	if err := s.saveFullSnapshot(initialState); err != nil {
+		return pkgerrors.Wrap(err, "failed to save initial snapshot")
+	}
+
+	log.WithField("offset", slot).Info("Initialized state-diff cache")
+	return nil
+}
+
 func keyForSnapshot(v int) ([]byte, error) {
 	switch v {
 	case version.Fulu:

beacon-chain/db/kv/wss.go

@@ -110,6 +110,8 @@ func (s *Store) SaveOrigin(ctx context.Context, serState, serBlock []byte) error
 	if err = s.SaveFinalizedCheckpoint(ctx, chkpt); err != nil {
 		return errors.Wrap(err, "save finalized checkpoint")
 	}
-
+	if err := s.initializeStateDiff(state.Slot(), state); err != nil {
+		return errors.Wrap(err, "failed to initialize state diff")
+	}
 	return nil
 }

beacon-chain/light-client/lightclient.go

@@ -413,7 +413,7 @@ func CreateDefaultLightClientUpdate(attestedBlock interfaces.ReadOnlySignedBeaco
 				SyncCommitteeSignature: make([]byte, 96),
 			},
 		}
-	case version.Electra, version.Fulu, version.Gloas:
+	case version.Electra, version.Fulu:
 		m = &pb.LightClientUpdateElectra{
 			AttestedHeader: &pb.LightClientHeaderDeneb{
 				Beacon: &pb.BeaconBlockHeader{
@@ -515,7 +515,7 @@ func ComputeWithdrawalsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 
 func BlockToLightClientHeader(
 	ctx context.Context,
-	attestedBlockVersion int,                   // this is the version that the light client header should be in, based on the attested block.
+	attestedBlockVersion int, // this is the version that the light client header should be in, based on the attested block.
 	block interfaces.ReadOnlySignedBeaconBlock, // this block is either the attested block, or the finalized block. in case of the latter, we might need to upgrade it to the attested block's version.
 ) (interfaces.LightClientHeader, error) {
 	if block.Version() > attestedBlockVersion {
@@ -543,7 +543,7 @@ func BlockToLightClientHeader(
 			Execution:       payloadHeader,
 			ExecutionBranch: payloadProof,
 		}
-	case version.Deneb, version.Electra, version.Fulu, version.Gloas:
+	case version.Deneb, version.Electra, version.Fulu:
 		payloadHeader, payloadProof, err := makeExecutionAndProofDeneb(ctx, block)
 		if err != nil {
 			return nil, errors.Wrap(err, "could not make execution payload header and proof")

beacon-chain/node/node.go

@@ -535,7 +535,12 @@ func openDB(ctx context.Context, dbPath string, clearer *dbClearer) (*kv.Store,
 	log.WithField("databasePath", dbPath).Info("Checking DB")
 
 	d, err := kv.NewKVStore(ctx, dbPath)
-	if err != nil {
+	if errors.Is(err, kv.ErrStateDiffIncompatible) {
+		log.WithError(err).Warn("Disabling state-diff feature")
+		cfg := features.Get()
+		cfg.EnableStateDiff = false
+		features.Init(cfg)
+	} else if err != nil {
 		return nil, errors.Wrapf(err, "could not create database at %s", dbPath)
 	}
 

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

@@ -83,6 +83,7 @@ func TestGetSpec(t *testing.T) {
 	config.ElectraForkEpoch = 107
 	config.FuluForkVersion = []byte("FuluForkVersion")
 	config.FuluForkEpoch = 109
+	config.GloasForkEpoch = 110
 	config.BLSWithdrawalPrefixByte = byte('b')
 	config.ETH1AddressWithdrawalPrefixByte = byte('c')
 	config.GenesisDelay = 24
@@ -134,6 +135,10 @@ func TestGetSpec(t *testing.T) {
 	config.AttestationDueBPS = primitives.BP(122)
 	config.AggregateDueBPS = primitives.BP(123)
 	config.ContributionDueBPS = primitives.BP(124)
+	config.AttestationDueBPSGloas = primitives.BP(126)
+	config.AggregateDueBPSGloas = primitives.BP(127)
+	config.SyncMessageDueBPSGloas = primitives.BP(128)
+	config.ContributionDueBPSGloas = primitives.BP(129)
 	config.TerminalBlockHash = common.HexToHash("TerminalBlockHash")
 	config.TerminalBlockHashActivationEpoch = 72
 	config.TerminalTotalDifficulty = "73"
@@ -215,7 +220,7 @@ func TestGetSpec(t *testing.T) {
 	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
 	data, ok := resp.Data.(map[string]any)
 	require.Equal(t, true, ok)
-	assert.Equal(t, 187, len(data))
+	assert.Equal(t, 192, len(data))
 	for k, v := range data {
 		t.Run(k, func(t *testing.T) {
 			switch k {
@@ -295,6 +300,8 @@ func TestGetSpec(t *testing.T) {
 				assert.Equal(t, "0x"+hex.EncodeToString([]byte("FuluForkVersion")), v)
 			case "FULU_FORK_EPOCH":
 				assert.Equal(t, "109", v)
+			case "GLOAS_FORK_EPOCH":
+				assert.Equal(t, "110", v)
 			case "MIN_ANCHOR_POW_BLOCK_DIFFICULTY":
 				assert.Equal(t, "1000", v)
 			case "BLS_WITHDRAWAL_PREFIX":
@@ -479,6 +486,14 @@ func TestGetSpec(t *testing.T) {
 				assert.Equal(t, "123", v)
 			case "CONTRIBUTION_DUE_BPS":
 				assert.Equal(t, "124", v)
+			case "ATTESTATION_DUE_BPS_GLOAS":
+				assert.Equal(t, "126", v)
+			case "AGGREGATE_DUE_BPS_GLOAS":
+				assert.Equal(t, "127", v)
+			case "SYNC_MESSAGE_DUE_BPS_GLOAS":
+				assert.Equal(t, "128", v)
+			case "CONTRIBUTION_DUE_BPS_GLOAS":
+				assert.Equal(t, "129", v)
 			case "MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT":
 				assert.Equal(t, "8", v)
 			case "MAX_REQUEST_LIGHT_CLIENT_UPDATES":

beacon-chain/state/stategen/migrate.go

@@ -137,7 +137,7 @@ func (s *State) migrateToColdHdiff(ctx context.Context, fRoot [32]byte) error {
 		if ctx.Err() != nil {
 			return ctx.Err()
 		}
-		_, lvl, err := s.beaconDB.SlotInDiffTree(slot)
+		offset, lvl, err := s.beaconDB.SlotInDiffTree(slot)
 		if err != nil {
 			log.WithError(err).Errorf("could not determine if slot %d is in diff tree", slot)
 			continue
@@ -145,6 +145,9 @@ func (s *State) migrateToColdHdiff(ctx context.Context, fRoot [32]byte) error {
 		if lvl == -1 {
 			continue
 		}
+		if uint64(slot) == offset {
+			continue
+		}
 		// The state needs to be saved.
 		// Try the epoch boundary cache first.
 		cached, exists, err := s.epochBoundaryStateCache.getBySlot(slot)

changelog/bastin_path-ephemeral-log.md

@@ -0,0 +1,3 @@
+### Ignored
+
+- Added a field `path` for the ephemeral log file initialization log.

changelog/farazdagi_fix-hashtree-darwin-amd64.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Fix Bazel build failure on macOS x86_64 (darwin_amd64) (adds missing assembly stub to hashtree patch).

changelog/fernantho_connect-merkle-proofs-with-endpoint.md

@@ -0,0 +1,6 @@
+### Added
+
+- Added new proofCollector type to ssz-query
+
+### Ignored
+- Added testing covering the production of Merkle proof from Phase0 beacon state and benchmarked against real Hoodi beacon state (Fulu version)

changelog/potuz_hdiff_start_db.md

@@ -0,0 +1,3 @@
+### Added
+
+- Initialize db with state-diff feature flag. 

changelog/terencechain_gloas-duty-timings.md

@@ -0,0 +1,2 @@
+### Added
+- Gloas-specific timing intervals for validator attestation, aggregation, and sync duties.

cmd/beacon-chain/main.go

@@ -160,6 +160,7 @@ var appFlags = []cli.Flag{
 	dasFlags.BackfillOldestSlot,
 	dasFlags.BlobRetentionEpochFlag,
 	flags.BatchVerifierLimit,
+	flags.StateDiffExponents,
 	flags.DisableEphemeralLogFile,
 }
 

cmd/beacon-chain/usage.go

@@ -74,6 +74,7 @@ var appHelpFlagGroups = []flagGroup{
 			flags.RPCHost,
 			flags.RPCPort,
 			flags.BatchVerifierLimit,
+			flags.StateDiffExponents,
 		},
 	},
 	{

config/features/flags.go

@@ -280,6 +280,7 @@ var BeaconChainFlags = combinedFlags([]cli.Flag{
 	DisableQUIC,
 	EnableDiscoveryReboot,
 	enableExperimentalAttestationPool,
+	EnableStateDiff,
 	forceHeadFlag,
 	blacklistRoots,
 	enableHashtree,

config/params/config.go

@@ -91,6 +91,10 @@ type BeaconChainConfig struct {
 	AggregateDueBPS                 primitives.BP    `yaml:"AGGREGATE_DUE_BPS" spec:"true"`                   // AggregateDueBPS defines the aggregate due time in basis points of the slot.
 	SyncMessageDueBPS               primitives.BP    `yaml:"SYNC_MESSAGE_DUE_BPS" spec:"true"`                // SyncMessageDueBPS defines the sync message due time in basis points of the slot.
 	ContributionDueBPS              primitives.BP    `yaml:"CONTRIBUTION_DUE_BPS" spec:"true"`                // ContributionDueBPS defines the contribution due time in basis points of the slot.
+	AttestationDueBPSGloas          primitives.BP    `yaml:"ATTESTATION_DUE_BPS_GLOAS" spec:"true"`           // AttestationDueBPSGloas defines the attestation due time in basis points of the slot (Gloas).
+	AggregateDueBPSGloas            primitives.BP    `yaml:"AGGREGATE_DUE_BPS_GLOAS" spec:"true"`             // AggregateDueBPSGloas defines the aggregate due time in basis points of the slot (Gloas).
+	SyncMessageDueBPSGloas          primitives.BP    `yaml:"SYNC_MESSAGE_DUE_BPS_GLOAS" spec:"true"`          // SyncMessageDueBPSGloas defines the sync message due time in basis points of the slot (Gloas).
+	ContributionDueBPSGloas         primitives.BP    `yaml:"CONTRIBUTION_DUE_BPS_GLOAS" spec:"true"`          // ContributionDueBPSGloas defines the contribution due time in basis points of the slot (Gloas).
 
 	// Ethereum PoW parameters.
 	DepositChainID         uint64 `yaml:"DEPOSIT_CHAIN_ID" spec:"true"`         // DepositChainID of the eth1 network. This used for replay protection.
@@ -188,6 +192,7 @@ type BeaconChainConfig struct {
 	ElectraForkEpoch     primitives.Epoch `yaml:"ELECTRA_FORK_EPOCH" spec:"true"`     // ElectraForkEpoch is used to represent the assigned fork epoch for electra.
 	FuluForkVersion      []byte           `yaml:"FULU_FORK_VERSION" spec:"true"`      // FuluForkVersion is used to represent the fork version for fulu.
 	FuluForkEpoch        primitives.Epoch `yaml:"FULU_FORK_EPOCH" spec:"true"`        // FuluForkEpoch is used to represent the assigned fork epoch for fulu.
+	GloasForkEpoch       primitives.Epoch `yaml:"GLOAS_FORK_EPOCH" spec:"true"`       // GloasForkEpoch is used to represent the assigned fork epoch for gloas.
 
 	ForkVersionSchedule map[[fieldparams.VersionLength]byte]primitives.Epoch // Schedule of fork epochs by version.
 	ForkVersionNames    map[[fieldparams.VersionLength]byte]string           // Human-readable names of fork versions.
@@ -343,6 +348,7 @@ func (b *BeaconChainConfig) VersionToForkEpochMap() map[int]primitives.Epoch {
 		version.Deneb:     b.DenebForkEpoch,
 		version.Electra:   b.ElectraForkEpoch,
 		version.Fulu:      b.FuluForkEpoch,
+		version.Gloas:     b.GloasForkEpoch,
 	}
 }
 

config/params/loader.go

@@ -224,6 +224,7 @@ func ConfigToYaml(cfg *BeaconChainConfig) []byte {
 		fmt.Sprintf("ELECTRA_FORK_VERSION: %#x", cfg.ElectraForkVersion),
 		fmt.Sprintf("FULU_FORK_EPOCH: %d", cfg.FuluForkEpoch),
 		fmt.Sprintf("FULU_FORK_VERSION: %#x", cfg.FuluForkVersion),
+		fmt.Sprintf("GLOAS_FORK_EPOCH: %d", cfg.GloasForkEpoch),
 		fmt.Sprintf("EPOCHS_PER_SUBNET_SUBSCRIPTION: %d", cfg.EpochsPerSubnetSubscription),
 		fmt.Sprintf("ATTESTATION_SUBNET_EXTRA_BITS: %d", cfg.AttestationSubnetExtraBits),
 		fmt.Sprintf("ATTESTATION_SUBNET_PREFIX_BITS: %d", cfg.AttestationSubnetPrefixBits),
@@ -246,6 +247,10 @@ func ConfigToYaml(cfg *BeaconChainConfig) []byte {
 		fmt.Sprintf("AGGREGATE_DUE_BPS: %d", cfg.AggregateDueBPS),
 		fmt.Sprintf("SYNC_MESSAGE_DUE_BPS: %d", cfg.SyncMessageDueBPS),
 		fmt.Sprintf("CONTRIBUTION_DUE_BPS: %d", cfg.ContributionDueBPS),
+		fmt.Sprintf("ATTESTATION_DUE_BPS_GLOAS: %d", cfg.AttestationDueBPSGloas),
+		fmt.Sprintf("AGGREGATE_DUE_BPS_GLOAS: %d", cfg.AggregateDueBPSGloas),
+		fmt.Sprintf("SYNC_MESSAGE_DUE_BPS_GLOAS: %d", cfg.SyncMessageDueBPSGloas),
+		fmt.Sprintf("CONTRIBUTION_DUE_BPS_GLOAS: %d", cfg.ContributionDueBPSGloas),
 	}
 
 	if len(cfg.BlobSchedule) > 0 {

config/params/loader_test.go

@@ -24,12 +24,9 @@ import (
 // These are variables that we don't use in Prysm. (i.e. future hardfork, light client... etc)
 // IMPORTANT: Use one field per line and sort these alphabetically to reduce conflicts.
 var placeholderFields = []string{
-	"AGGREGATE_DUE_BPS_GLOAS",
 	"ATTESTATION_DEADLINE",
-	"ATTESTATION_DUE_BPS_GLOAS",
 	"BLOB_SIDECAR_SUBNET_COUNT_FULU",
 	"CELLS_PER_EXT_BLOB",
-	"CONTRIBUTION_DUE_BPS_GLOAS",
 	"EIP6110_FORK_EPOCH",
 	"EIP6110_FORK_VERSION",
 	"EIP7002_FORK_EPOCH",
@@ -45,7 +42,6 @@ var placeholderFields = []string{
 	"EPOCHS_PER_SHUFFLING_PHASE",
 	"FIELD_ELEMENTS_PER_CELL",     // Configured as a constant in config/fieldparams/mainnet.go
 	"FIELD_ELEMENTS_PER_EXT_BLOB", // Configured in proto/ssz_proto_library.bzl
-	"GLOAS_FORK_EPOCH",
 	"GLOAS_FORK_VERSION",
 	"INCLUSION_LIST_SUBMISSION_DEADLINE",
 	"INCLUSION_LIST_SUBMISSION_DUE_BPS",
@@ -60,7 +56,6 @@ var placeholderFields = []string{
 	"PROPOSER_INCLUSION_LIST_CUTOFF",
 	"PROPOSER_INCLUSION_LIST_CUTOFF_BPS",
 	"PROPOSER_SELECTION_GAP",
-	"SYNC_MESSAGE_DUE_BPS_GLOAS",
 	"TARGET_NUMBER_OF_PEERS",
 	"UPDATE_TIMEOUT",
 	"VIEW_FREEZE_CUTOFF_BPS",

config/params/mainnet_config.go

@@ -32,6 +32,8 @@ const (
 	mainnetElectraForkEpoch = 364032 // May 7, 2025, 10:05:11 UTC
 	// Fulu Fork Epoch for mainnet config
 	mainnetFuluForkEpoch = 411392 // December 3, 2025, 09:49:11pm UTC
+	// Gloas Fork Epoch for mainnet config
+	mainnetGloasForkEpoch = math.MaxUint64
 )
 
 var mainnetNetworkConfig = &NetworkConfig{
@@ -121,11 +123,15 @@ var mainnetBeaconConfig = &BeaconChainConfig{
 	IntervalsPerSlot:                3,
 
 	// Time-based protocol parameters.
-	ProposerReorgCutoffBPS: primitives.BP(1667),
-	AttestationDueBPS:      primitives.BP(3333),
-	AggregateDueBPS:        primitives.BP(6667),
-	SyncMessageDueBPS:      primitives.BP(3333),
-	ContributionDueBPS:     primitives.BP(6667),
+	ProposerReorgCutoffBPS:  primitives.BP(1667),
+	AttestationDueBPS:       primitives.BP(3333),
+	AggregateDueBPS:         primitives.BP(6667),
+	SyncMessageDueBPS:       primitives.BP(3333),
+	ContributionDueBPS:      primitives.BP(6667),
+	AttestationDueBPSGloas:  primitives.BP(2500),
+	AggregateDueBPSGloas:    primitives.BP(5000),
+	SyncMessageDueBPSGloas:  primitives.BP(2500),
+	ContributionDueBPSGloas: primitives.BP(5000),
 
 	// Ethereum PoW parameters.
 	DepositChainID:         1, // Chain ID of eth1 mainnet.
@@ -235,6 +241,7 @@ var mainnetBeaconConfig = &BeaconChainConfig{
 	ElectraForkEpoch:     mainnetElectraForkEpoch,
 	FuluForkVersion:      []byte{6, 0, 0, 0},
 	FuluForkEpoch:        mainnetFuluForkEpoch,
+	GloasForkEpoch:       mainnetGloasForkEpoch,
 
 	// New values introduced in Altair hard fork 1.
 	// Participation flag indices.

config/params/minimal_config.go

@@ -35,6 +35,10 @@ func MinimalSpecConfig() *BeaconChainConfig {
 	// Time parameters
 	minimalConfig.SecondsPerSlot = 6
 	minimalConfig.SlotDurationMilliseconds = 6000
+	minimalConfig.AttestationDueBPSGloas = 2500
+	minimalConfig.AggregateDueBPSGloas = 5000
+	minimalConfig.SyncMessageDueBPSGloas = 2500
+	minimalConfig.ContributionDueBPSGloas = 5000
 	minimalConfig.MinAttestationInclusionDelay = 1
 	minimalConfig.SlotsPerEpoch = 8
 	minimalConfig.SqrRootSlotsPerEpoch = 2
@@ -98,6 +102,7 @@ func MinimalSpecConfig() *BeaconChainConfig {
 	minimalConfig.ElectraForkEpoch = math.MaxUint64
 	minimalConfig.FuluForkVersion = []byte{6, 0, 0, 1}
 	minimalConfig.FuluForkEpoch = math.MaxUint64
+	minimalConfig.GloasForkEpoch = minimalConfig.FarFutureEpoch
 
 	minimalConfig.SyncCommitteeSize = 32
 	minimalConfig.InactivityScoreBias = 4

encoding/bytesutil/integers.go

@@ -163,3 +163,18 @@ func Uint256ToSSZBytes(num string) ([]byte, error) {
 	}
 	return PadTo(ReverseByteOrder(uint256.Bytes()), 32), nil
 }
+
+// PutLittleEndian writes an unsigned integer value in little-endian format.
+// Supports sizes 1, 2, 4, or 8 bytes for uint8/16/32/64 respectively.
+func PutLittleEndian(dst []byte, val uint64, size int) {
+	switch size {
+	case 1:
+		dst[0] = byte(val)
+	case 2:
+		binary.LittleEndian.PutUint16(dst, uint16(val))
+	case 4:
+		binary.LittleEndian.PutUint32(dst, uint32(val))
+	case 8:
+		binary.LittleEndian.PutUint64(dst, val)
+	}
+}

encoding/ssz/query/BUILD.bazel

@@ -9,7 +9,9 @@ go_library(
         "container.go",
         "generalized_index.go",
         "list.go",
+        "merkle_proof.go",
         "path.go",
+        "proof_collector.go",
         "query.go",
         "ssz_info.go",
         "ssz_object.go",
@@ -20,7 +22,12 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v7/encoding/ssz/query",
     visibility = ["//visibility:public"],
     deps = [
+        "//container/trie:go_default_library",
+        "//crypto/hash/htr:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
+        "//math:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
     ],
 )
@@ -29,15 +36,24 @@ go_test(
     name = "go_default_test",
     srcs = [
         "generalized_index_test.go",
+        "merkle_proof_test.go",
         "path_test.go",
+        "proof_collector_test.go",
         "query_test.go",
         "tag_parser_test.go",
     ],
+    embed = [":go_default_library"],
     deps = [
-        ":go_default_library",
+        "//beacon-chain/state/stateutil:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//encoding/ssz:go_default_library",
         "//encoding/ssz/query/testutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
         "//proto/ssz_query/testing:go_default_library",
         "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
     ],
 )

encoding/ssz/query/merkle_proof.go

@@ -0,0 +1,34 @@
+package query
+
+import (
+	"fmt"
+	"reflect"
+
+	fastssz "github.com/prysmaticlabs/fastssz"
+)
+
+// Prove is the entrypoint to generate an SSZ Merkle proof for the given generalized index.
+// Parameters:
+// - gindex: the generalized index of the node to prove inclusion for.
+// Returns:
+// - fastssz.Proof: the Merkle proof containing the leaf, index, and sibling hashes.
+// - error: any error encountered during proof generation.
+func (info *SszInfo) Prove(gindex uint64) (*fastssz.Proof, error) {
+	if info == nil {
+		return nil, fmt.Errorf("nil SszInfo")
+	}
+
+	collector := newProofCollector()
+	collector.addTarget(gindex)
+
+	// info.source is guaranteed to be valid and dereferenced by AnalyzeObject
+	v := reflect.ValueOf(info.source).Elem()
+
+	// Start the merkleization and proof collection process.
+	// In SSZ generalized indices, the root is always at index 1.
+	if _, err := collector.merkleize(info, v, 1); err != nil {
+		return nil, err
+	}
+
+	return collector.toProof()
+}

encoding/ssz/query/merkle_proof_test.go

@@ -0,0 +1,163 @@
+package query_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/go-bitfield"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v7/encoding/ssz/query"
+	eth "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v7/testing/require"
+	"github.com/OffchainLabs/prysm/v7/testing/util"
+	ssz "github.com/prysmaticlabs/fastssz"
+)
+
+func TestProve_FixedTestContainer(t *testing.T) {
+	obj := createFixedTestContainer()
+
+	tests := []string{
+		".field_uint32",
+		".nested.value2",
+		".vector_field[3]",
+		".bitvector64_field",
+		".trailing_field",
+	}
+
+	for _, tc := range tests {
+		t.Run(tc, func(t *testing.T) {
+			proveAndVerify(t, obj, tc)
+		})
+	}
+}
+
+func TestProve_VariableTestContainer(t *testing.T) {
+	obj := createVariableTestContainer()
+
+	tests := []string{
+		".leading_field",
+		".field_list_uint64[2]",
+		"len(field_list_uint64)",
+		".nested.nested_list_field[1]",
+		".variable_container_list[0].inner_1.field_list_uint64[1]",
+	}
+
+	for _, tc := range tests {
+		t.Run(tc, func(t *testing.T) {
+			proveAndVerify(t, obj, tc)
+		})
+	}
+}
+
+func TestProve_BeaconBlock(t *testing.T) {
+	randaoReveal := make([]byte, 96)
+	for i := range randaoReveal {
+		randaoReveal[i] = 0x42
+	}
+	root32 := make([]byte, 32)
+	for i := range root32 {
+		root32[i] = 0x24
+	}
+	sig := make([]byte, 96)
+	for i := range sig {
+		sig[i] = 0x99
+	}
+
+	att := &eth.Attestation{
+		AggregationBits: bitfield.Bitlist{0x01},
+		Data: &eth.AttestationData{
+			Slot:            1,
+			CommitteeIndex:  1,
+			BeaconBlockRoot: root32,
+			Source: &eth.Checkpoint{
+				Epoch: 1,
+				Root:  root32,
+			},
+			Target: &eth.Checkpoint{
+				Epoch: 1,
+				Root:  root32,
+			},
+		},
+		Signature: sig,
+	}
+
+	b := util.NewBeaconBlock()
+	b.Block.Slot = 123
+	b.Block.Body.RandaoReveal = randaoReveal
+	b.Block.Body.Attestations = []*eth.Attestation{att}
+
+	sb, err := blocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+
+	protoBlock, err := sb.Block().Proto()
+	require.NoError(t, err)
+
+	obj, ok := protoBlock.(query.SSZObject)
+	require.Equal(t, true, ok, "block proto does not implement query.SSZObject")
+
+	tests := []string{
+		".slot",
+		".body.randao_reveal",
+		".body.attestations[0].data.slot",
+		"len(body.attestations)",
+	}
+
+	for _, tc := range tests {
+		t.Run(tc, func(t *testing.T) {
+			proveAndVerify(t, obj, tc)
+		})
+	}
+}
+
+func TestProve_BeaconState(t *testing.T) {
+	st, _ := util.DeterministicGenesisState(t, 16)
+	require.NoError(t, st.SetSlot(primitives.Slot(42)))
+
+	sszObj, ok := st.ToProtoUnsafe().(query.SSZObject)
+	require.Equal(t, true, ok, "state proto does not implement query.SSZObject")
+
+	tests := []string{
+		".slot",
+		".latest_block_header",
+		".validators[0].effective_balance",
+		"len(validators)",
+	}
+
+	for _, tc := range tests {
+		t.Run(tc, func(t *testing.T) {
+			proveAndVerify(t, sszObj, tc)
+		})
+	}
+}
+
+// proveAndVerify helper to analyze an object, generate a merkle proof for the given path,
+// and verify the proof against the object's root.
+func proveAndVerify(t *testing.T, obj query.SSZObject, pathStr string) {
+	t.Helper()
+
+	info, err := query.AnalyzeObject(obj)
+	require.NoError(t, err)
+
+	path, err := query.ParsePath(pathStr)
+	require.NoError(t, err)
+
+	gi, err := query.GetGeneralizedIndexFromPath(info, path)
+	require.NoError(t, err)
+
+	proof, err := info.Prove(gi)
+	require.NoError(t, err)
+	require.Equal(t, int(gi), proof.Index)
+
+	root, err := obj.HashTreeRoot()
+	require.NoError(t, err)
+
+	ok, err := ssz.VerifyProof(root[:], proof)
+	require.NoError(t, err)
+	require.Equal(t, true, ok, "merkle proof verification failed")
+
+	require.Equal(t, 32, len(proof.Leaf))
+	for i, h := range proof.Hashes {
+		require.Equal(t, 32, len(h), "proof hash %d is not 32 bytes", i)
+	}
+
+}

encoding/ssz/query/proof_collector.go

@@ -0,0 +1,672 @@
+package query
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/bits"
+	"reflect"
+	"runtime"
+	"slices"
+	"sync"
+
+	"github.com/OffchainLabs/go-bitfield"
+	"github.com/OffchainLabs/prysm/v7/container/trie"
+	"github.com/OffchainLabs/prysm/v7/crypto/hash/htr"
+	"github.com/OffchainLabs/prysm/v7/encoding/bytesutil"
+	ssz "github.com/OffchainLabs/prysm/v7/encoding/ssz"
+	"github.com/OffchainLabs/prysm/v7/math"
+	fastssz "github.com/prysmaticlabs/fastssz"
+)
+
+// proofCollector collects sibling hashes and leaves needed for Merkle proofs.
+//
+// Multiproof-ready design:
+// - requiredSiblings/requiredLeaves store which gindices we want to collect (registered before merkleization).
+// - siblings/leaves store the actual collected hashes.
+//
+// Concurrency:
+// - required* maps are read-only during merkleization.
+// - siblings/leaves writes are protected by mutex.
+type proofCollector struct {
+	sync.Mutex
+
+	// Required gindices (registered before merkleization)
+	requiredSiblings map[uint64]struct{}
+	requiredLeaves   map[uint64]struct{}
+
+	// Collected hashes
+	siblings map[uint64][32]byte
+	leaves   map[uint64][32]byte
+}
+
+func newProofCollector() *proofCollector {
+	return &proofCollector{
+		requiredSiblings: make(map[uint64]struct{}),
+		requiredLeaves:   make(map[uint64]struct{}),
+		siblings:         make(map[uint64][32]byte),
+		leaves:           make(map[uint64][32]byte),
+	}
+}
+
+func (pc *proofCollector) reset() {
+	pc.Lock()
+	defer pc.Unlock()
+
+	pc.requiredSiblings = make(map[uint64]struct{})
+	pc.requiredLeaves = make(map[uint64]struct{})
+	pc.siblings = make(map[uint64][32]byte)
+	pc.leaves = make(map[uint64][32]byte)
+}
+
+// addTarget register the target leaf and its required sibling nodes for proof construction.
+// Registration should happen before merkleization begins.
+func (pc *proofCollector) addTarget(gindex uint64) {
+	pc.Lock()
+	defer pc.Unlock()
+
+	pc.requiredLeaves[gindex] = struct{}{}
+
+	// Walk from the target leaf up to (but not including) the root (gindex=1).
+	// At each step, register the sibling node required to prove inclusion.
+	nodeGindex := gindex
+	for nodeGindex > 1 {
+		siblingGindex := nodeGindex ^ 1 // flip the last bit: left<->right sibling
+		pc.requiredSiblings[siblingGindex] = struct{}{}
+
+		// Move to parent
+		nodeGindex /= 2
+	}
+}
+
+// toProof converts the collected siblings and leaves into a fastssz.Proof structure.
+// Current behavior expects a single target leaf (single proof).
+func (pc *proofCollector) toProof() (*fastssz.Proof, error) {
+	pc.Lock()
+	defer pc.Unlock()
+
+	proof := &fastssz.Proof{}
+	if len(pc.leaves) == 0 {
+		return nil, errors.New("no leaves collected: add target leaves before merkleization")
+	}
+
+	leafGindices := make([]uint64, 0, len(pc.leaves))
+	for g := range pc.leaves {
+		leafGindices = append(leafGindices, g)
+	}
+	slices.Sort(leafGindices)
+
+	// single proof resides in leafGindices[0]
+	targetGindex := leafGindices[0]
+	proofIndex, err := math.Int(targetGindex)
+	if err != nil {
+		return nil, fmt.Errorf("gindex %d overflows int: %w", targetGindex, err)
+	}
+	proof.Index = proofIndex
+
+	// store the leaf
+	leaf := pc.leaves[targetGindex]
+	leafBuf := make([]byte, 32)
+	copy(leafBuf, leaf[:])
+	proof.Leaf = leafBuf
+
+	// Walk from target up to root, collecting siblings.
+	steps := bits.Len64(targetGindex) - 1
+	proof.Hashes = make([][]byte, 0, steps)
+
+	for targetGindex > 1 {
+		sib := targetGindex ^ 1
+		h, ok := pc.siblings[sib]
+		if !ok {
+			return nil, fmt.Errorf("missing sibling hash for gindex %d", sib)
+		}
+		proof.Hashes = append(proof.Hashes, h[:])
+		targetGindex /= 2
+	}
+
+	return proof, nil
+}
+
+// collectLeaf checks if the given gindex is a required leaf for the proof,
+// and if so, stores the provided leaf hash in the collector.
+func (pc *proofCollector) collectLeaf(gindex uint64, leaf [32]byte) {
+	if _, ok := pc.requiredLeaves[gindex]; !ok {
+		return
+	}
+	pc.Lock()
+	pc.leaves[gindex] = leaf
+	pc.Unlock()
+}
+
+// collectSibling stores the hash for a sibling node identified by gindex.
+// It only stores the hash if gindex was pre-registered via addTarget (present in requiredSiblings).
+// Writes to the collected siblings map are protected by the collector mutex.
+func (pc *proofCollector) collectSibling(gindex uint64, hash [32]byte) {
+	if _, ok := pc.requiredSiblings[gindex]; !ok {
+		return
+	}
+	pc.Lock()
+	pc.siblings[gindex] = hash
+	pc.Unlock()
+}
+
+// Merkleizers and proof collection methods
+
+// merkleize recursively traverses an SSZ info and computes the Merkle root of the subtree.
+//
+// Proof collection:
+//   - During traversal it calls collectLeaf/collectSibling with the SSZ generalized indices (gindices)
+//     of visited nodes.
+//   - The collector only stores hashes for gindices that were pre-registered via addTarget
+//     (requiredLeaves/requiredSiblings). This makes the traversal multiproof-ready: you can register
+//     multiple targets before calling merkleize.
+//
+// SSZ types handled: basic types, containers, lists, vectors, bitlists, and bitvectors.
+//
+// Parameters:
+// - info: SSZ type metadata for the current value.
+// - v: reflect.Value of the current value.
+// - currentGindex: generalized index of the current subtree root.
+//
+// Returns:
+// - [32]byte: Merkle root of the current subtree.
+// - error: any error encountered during traversal/merkleization.
+func (pc *proofCollector) merkleize(info *SszInfo, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	if info.sszType.isBasic() {
+		return pc.merkleizeBasicType(info.sszType, v, currentGindex)
+	}
+	switch info.sszType {
+	case Container:
+		return pc.merkleizeContainer(info, v, currentGindex)
+	case List:
+		return pc.merkleizeList(info, v, currentGindex)
+	case Vector:
+		return pc.merkleizeVector(info, v, currentGindex)
+	case Bitlist:
+		return pc.merkleizeBitlist(info, v, currentGindex)
+	case Bitvector:
+		return pc.merkleizeBitvector(info, v, currentGindex)
+	default:
+		return [32]byte{}, fmt.Errorf("unsupported SSZ type: %v", info.sszType)
+	}
+}
+
+// merkleizeBasicType serializes a basic SSZ value into a 32-byte leaf chunk (little-endian, zero-padded).
+//
+// Proof collection:
+// - It calls collectLeaf(currentGindex, leaf) and stores the leaf if currentGindex was pre-registered via addTarget.
+//
+// Parameters:
+// - t: the SSZType (basic).
+// - v: the reflect.Value of the basic value.
+// - currentGindex: the generalized index (gindex) of this leaf.
+//
+// Returns:
+// - [32]byte: the 32-byte SSZ leaf chunk.
+// - error: if the SSZType is not a supported basic type.
+func (pc *proofCollector) merkleizeBasicType(t SSZType, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	var leaf [32]byte
+
+	// Serialize the value into a 32-byte chunk (little-endian, zero-padded)
+	switch t {
+	case Uint8:
+		leaf[0] = uint8(v.Uint())
+	case Uint16:
+		binary.LittleEndian.PutUint16(leaf[:2], uint16(v.Uint()))
+	case Uint32:
+		binary.LittleEndian.PutUint32(leaf[:4], uint32(v.Uint()))
+	case Uint64:
+		binary.LittleEndian.PutUint64(leaf[:8], v.Uint())
+	case Boolean:
+		if v.Bool() {
+			leaf[0] = 1
+		}
+	default:
+		return [32]byte{}, fmt.Errorf("unexpected basic type: %v", t)
+	}
+
+	pc.collectLeaf(currentGindex, leaf)
+
+	return leaf, nil
+}
+
+// merkleizeContainer computes the Merkle root of an SSZ container by:
+//  1. Merkleizing each field into a 32-byte subtree root
+//  2. Merkleizing the field roots into the container root (padding to the next power-of-2)
+//
+// Generalized indices (gindices): depth = ssz.Depth(uint64(N)) and field i has gindex = (currentGindex << depth) + uint64(i).
+// Proof collection: merkleize() computes each field root, merkleizeVectorAndCollect collects required siblings, and collectLeaf stores the container root if registered.
+//
+// Parameters:
+// - info: SSZ type metadata for the container.
+// - v: reflect.Value of the container value.
+// - currentGindex: generalized index (gindex) of the container root.
+//
+// Returns:
+// - [32]byte: Merkle root of the container.
+// - error: any error encountered while merkleizing fields.
+func (pc *proofCollector) merkleizeContainer(info *SszInfo, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	// If the container root itself is the target, compute directly and return early.
+	// This avoids full subtree merkleization when we only need the root.
+	if _, ok := pc.requiredLeaves[currentGindex]; ok {
+		root, err := info.HashTreeRoot()
+		if err != nil {
+			return [32]byte{}, err
+		}
+		pc.collectLeaf(currentGindex, root)
+		return root, nil
+	}
+
+	ci, err := info.ContainerInfo()
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	v = dereferencePointer(v)
+
+	// Calculate depth: how many levels from container root to field leaves
+	numFields := len(ci.order)
+	depth := ssz.Depth(uint64(numFields))
+
+	// Step 1: Compute HTR for each subtree (field)
+	fieldRoots := make([][32]byte, numFields)
+
+	for i, name := range ci.order {
+		fieldInfo := ci.fields[name]
+		fieldVal := v.FieldByName(fieldInfo.goFieldName)
+
+		// Field i's gindex: shift currentGindex left by depth, then OR with field index
+		fieldGindex := currentGindex<<depth + uint64(i)
+
+		htr, err := pc.merkleize(fieldInfo.sszInfo, fieldVal, fieldGindex)
+		if err != nil {
+			return [32]byte{}, fmt.Errorf("field %s: %w", name, err)
+		}
+		fieldRoots[i] = htr
+	}
+
+	// Step 2: Merkleize the field hashes into the container root,
+	// collecting sibling hashes if target is within this subtree
+	root := pc.merkleizeVectorAndCollect(fieldRoots, currentGindex, uint64(depth))
+
+	return root, nil
+}
+
+// merkleizeVectorBody computes the Merkle root of the "data" subtree for vector-like SSZ types
+// (vectors and the data-part of lists/bitlists).
+//
+// Generalized indices (gindices): depth = ssz.Depth(limit); leafBase = subtreeRootGindex << depth; element/chunk i gindex = leafBase + uint64(i).
+// Proof collection: merkleize() is called for composite elements; merkleizeVectorAndCollect collects required siblings at this layer.
+// Padding: merkleizeVectorAndCollect uses trie.ZeroHashes as needed.
+//
+// Parameters:
+// - elemInfo: SSZ type metadata for the element.
+// - v: reflect.Value of the vector/list data.
+// - length: number of actual elements present.
+// - limit: virtual leaf capacity used for padding/Depth (fixed length for vectors, limit for lists).
+// - subtreeRootGindex: gindex of the data subtree root.
+//
+// Returns:
+// - [32]byte: Merkle root of the data subtree.
+// - error: any error encountered while merkleizing composite elements.
+func (pc *proofCollector) merkleizeVectorBody(elemInfo *SszInfo, v reflect.Value, length int, limit uint64, subtreeRootGindex uint64) ([32]byte, error) {
+	depth := uint64(ssz.Depth(limit))
+
+	var chunks [][32]byte
+	if elemInfo.sszType.isBasic() {
+		// Serialize basic elements and pack into 32-byte chunks using ssz.PackByChunk.
+		elemSize, err := math.Int(itemLength(elemInfo))
+		if err != nil {
+			return [32]byte{}, fmt.Errorf("element size %d overflows int: %w", itemLength(elemInfo), err)
+		}
+		serialized := make([][]byte, length)
+		// Single contiguous allocation for all element data
+		allData := make([]byte, length*elemSize)
+		for i := range length {
+			buf := allData[i*elemSize : (i+1)*elemSize]
+			elem := v.Index(i)
+			if elemInfo.sszType == Boolean && elem.Bool() {
+				buf[0] = 1
+			} else {
+				bytesutil.PutLittleEndian(buf, elem.Uint(), elemSize)
+			}
+			serialized[i] = buf
+		}
+		chunks, err = ssz.PackByChunk(serialized)
+		if err != nil {
+			return [32]byte{}, err
+		}
+	} else {
+		// Composite elements: compute each element root (no padding here; merkleizeVectorAndCollect pads).
+		chunks = make([][32]byte, length)
+
+		// Fall back to per-element merkleization with proper gindices for proof collection.
+		// Parallel execution
+		workerCount := min(runtime.GOMAXPROCS(0), length)
+
+		jobs := make(chan int, workerCount*16)
+		errCh := make(chan error, 1) // only need the first error
+		stopCh := make(chan struct{})
+		var stopOnce sync.Once
+		var wg sync.WaitGroup
+
+		worker := func() {
+			defer wg.Done()
+			for idx := range jobs {
+				select {
+				case <-stopCh:
+					return
+				default:
+				}
+
+				elemGindex := subtreeRootGindex<<depth + uint64(idx)
+				htr, err := pc.merkleize(elemInfo, v.Index(idx), elemGindex)
+				if err != nil {
+					stopOnce.Do(func() { close(stopCh) })
+					select {
+					case errCh <- fmt.Errorf("index %d: %w", idx, err):
+					default:
+					}
+					return
+				}
+				chunks[idx] = htr
+			}
+		}
+
+		wg.Add(workerCount)
+		for range workerCount {
+			go worker()
+		}
+
+		// Enqueue jobs; stop early if any worker reports an error.
+	enqueue:
+		for i := range length {
+			select {
+			case <-stopCh:
+				break enqueue
+			case jobs <- i:
+			}
+		}
+		close(jobs)
+
+		wg.Wait()
+
+		select {
+		case err := <-errCh:
+			return [32]byte{}, err
+		default:
+		}
+	}
+
+	root := pc.merkleizeVectorAndCollect(chunks, subtreeRootGindex, depth)
+	return root, nil
+}
+
+// merkleizeVector computes the Merkle root of an SSZ vector (fixed-length).
+//
+// Generalized indices (gindices): currentGindex is the gindex of the vector root; element/chunk gindices are derived
+// inside merkleizeVectorBody using leafBase = currentGindex << ssz.Depth(leaves).
+//
+// Proof collection: merkleizeVectorBody performs element/chunk merkleization and collects required siblings at the
+// vector layer; collectLeaf stores the vector root if currentGindex was registered via addTarget.
+//
+// Parameters:
+// - info: SSZ type metadata for the vector.
+// - v: reflect.Value of the vector value.
+// - currentGindex: generalized index (gindex) of the vector root.
+//
+// Returns:
+// - [32]byte: Merkle root of the vector.
+// - error: any error encountered while merkleizing composite elements.
+func (pc *proofCollector) merkleizeVector(info *SszInfo, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	vi, err := info.VectorInfo()
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	length, err := math.Int(vi.Length())
+	if err != nil {
+		return [32]byte{}, fmt.Errorf("vector length %d overflows int: %w", vi.Length(), err)
+	}
+	elemInfo := vi.element
+
+	// Determine the virtual leaf capacity for the vector.
+	leaves, err := getChunkCount(info)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	root, err := pc.merkleizeVectorBody(elemInfo, v, length, leaves, currentGindex)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	// If the vector root itself is the target
+	pc.collectLeaf(currentGindex, root)
+
+	return root, nil
+}
+
+// merkleizeList computes the Merkle root of an SSZ list by merkleizing its data subtree and mixing in the length.
+//
+// Generalized indices (gindices): dataRoot is the left child of the list root (dataRootGindex = currentGindex*2); the length mixin is the right child (currentGindex*2+1).
+// Proof collection: merkleizeVectorBody computes the data root (collecting required siblings in the data subtree), and mixinLengthAndCollect collects required siblings at the length-mixin level; collectLeaf stores the list root if registered.
+//
+// Parameters:
+// - info: SSZ type metadata for the list.
+// - v: reflect.Value of the list value.
+// - currentGindex: generalized index (gindex) of the list root.
+//
+// Returns:
+// - [32]byte: Merkle root of the list.
+// - error: any error encountered while merkleizing the data subtree.
+func (pc *proofCollector) merkleizeList(info *SszInfo, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	li, err := info.ListInfo()
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	length := v.Len()
+	elemInfo := li.element
+
+	chunks := make([][32]byte, 2)
+	// Compute the length hash (little-endian uint256)
+	binary.LittleEndian.PutUint64(chunks[1][:8], uint64(length))
+
+	// Data subtree root is the left child of the list root.
+	dataRootGindex := currentGindex * 2
+
+	// Compute virtual leaf capacity for the data subtree.
+	leaves, err := getChunkCount(info)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	chunks[0], err = pc.merkleizeVectorBody(elemInfo, v, length, leaves, dataRootGindex)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	// Handle the length mixin level (and proof bookkeeping at this level).
+	// Compute the final list root: hash(dataRoot || lengthHash)
+	root := pc.mixinLengthAndCollect(currentGindex, chunks)
+
+	// If the list root itself is the target
+	pc.collectLeaf(currentGindex, root)
+
+	return root, nil
+}
+
+// merkleizeBitvectorBody computes the Merkle root of a bitvector-like byte sequence by packing it into 32-byte chunks
+// and merkleizing those chunks as a fixed-capacity vector (padding with trie.ZeroHashes as needed).
+//
+// Generalized indices (gindices): depth = ssz.Depth(chunkLimit); leafBase = subtreeRootGindex << depth; chunk i uses gindex = leafBase + uint64(i).
+// Proof collection: merkleizeVectorAndCollect collects required sibling hashes at the chunk-merkleization layer.
+//
+// Parameters:
+// - data: raw byte sequence representing the bitvector payload.
+// - chunkLimit: fixed/limit number of 32-byte chunks (used for padding/Depth).
+// - subtreeRootGindex: gindex of the bitvector data subtree root.
+//
+// Returns:
+// - [32]byte: Merkle root of the bitvector data subtree.
+// - error: any error encountered while packing data into chunks.
+func (pc *proofCollector) merkleizeBitvectorBody(data []byte, chunkLimit uint64, subtreeRootGindex uint64) ([32]byte, error) {
+	depth := ssz.Depth(chunkLimit)
+	chunks, err := ssz.PackByChunk([][]byte{data})
+	if err != nil {
+		return [32]byte{}, err
+	}
+	root := pc.merkleizeVectorAndCollect(chunks, subtreeRootGindex, uint64(depth))
+	return root, nil
+}
+
+// merkleizeBitvector computes the Merkle root of a fixed-length SSZ bitvector and collects proof nodes for targets.
+//
+// Parameters:
+// - info: SSZ type metadata for the bitvector.
+// - v: reflect.Value of the bitvector value.
+// - currentGindex: generalized index (gindex) of the bitvector root.
+//
+// Returns:
+// - [32]byte: Merkle root of the bitvector.
+// - error: any error encountered during packing or merkleization.
+func (pc *proofCollector) merkleizeBitvector(info *SszInfo, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	bitvectorBytes := v.Bytes()
+	if len(bitvectorBytes) == 0 {
+		return [32]byte{}, fmt.Errorf("bitvector field is uninitialized (nil or empty slice)")
+	}
+
+	// Compute virtual leaf capacity for the bitvector.
+	numChunks, err := getChunkCount(info)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	root, err := pc.merkleizeBitvectorBody(bitvectorBytes, numChunks, currentGindex)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	pc.collectLeaf(currentGindex, root)
+
+	return root, nil
+}
+
+// merkleizeBitlist computes the Merkle root of an SSZ bitlist by merkleizing its data chunks and mixing in the bit length.
+//
+// Generalized indices (gindices): dataRoot is the left child (dataRootGindex = currentGindex*2) and the length mixin is the right child (currentGindex*2+1).
+// Proof collection: merkleizeBitvectorBody computes the data root (collecting required siblings under dataRootGindex), and mixinLengthAndCollect collects required siblings at the length-mixin level; collectLeaf stores the bitlist root if registered.
+//
+// Parameters:
+// - info: SSZ type metadata for the bitlist.
+// - v: reflect.Value of the bitlist value.
+// - currentGindex: generalized index (gindex) of the bitlist root.
+//
+// Returns:
+// - [32]byte: Merkle root of the bitlist.
+// - error: any error encountered while merkleizing the data subtree.
+func (pc *proofCollector) merkleizeBitlist(info *SszInfo, v reflect.Value, currentGindex uint64) ([32]byte, error) {
+	bi, err := info.BitlistInfo()
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	bitlistBytes := v.Bytes()
+
+	// Use go-bitfield to get bytes with termination bit cleared
+	bl := bitfield.Bitlist(bitlistBytes)
+	data := bl.BytesNoTrim()
+
+	// Get the bit length from bitlistInfo
+	bitLength := bi.Length()
+
+	// Get the chunk limit from getChunkCount
+	limitChunks, err := getChunkCount(info)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	chunks := make([][32]byte, 2)
+	// Compute the length hash (little-endian uint256)
+	binary.LittleEndian.PutUint64(chunks[1][:8], uint64(bitLength))
+
+	dataRootGindex := currentGindex * 2
+	chunks[0], err = pc.merkleizeBitvectorBody(data, limitChunks, dataRootGindex)
+	if err != nil {
+		return [32]byte{}, err
+	}
+
+	// Handle the length mixin level (and proof bookkeeping at this level).
+	root := pc.mixinLengthAndCollect(currentGindex, chunks)
+
+	pc.collectLeaf(currentGindex, root)
+
+	return root, nil
+}
+
+// merkleizeVectorAndCollect merkleizes a slice of 32-byte leaf nodes into a subtree root, padding to a virtual size of 2^depth.
+//
+// Generalized indices (gindices): at layer i (0-based), nodes have gindices levelBase = subtreeGeneralizedIndex << (depth-i) and node gindex = levelBase + idx.
+// Proof collection: for each layer it calls collectSibling(nodeGindex, nodeHash) and stores only those gindices registered via addTarget.
+//
+// Parameters:
+// - elements: leaf-level hashes (may be shorter than 2^depth; padding is applied with trie.ZeroHashes).
+// - subtreeGeneralizedIndex: gindex of the subtree root.
+// - depth: number of merkleization layers from subtree root to leaves.
+//
+// Returns:
+// - [32]byte: Merkle root of the subtree.
+func (pc *proofCollector) merkleizeVectorAndCollect(elements [][32]byte, subtreeGeneralizedIndex uint64, depth uint64) [32]byte {
+	// Return zerohash at depth
+	if len(elements) == 0 {
+		return trie.ZeroHashes[depth]
+	}
+	for i := range depth {
+		layerLen := len(elements)
+		oddNodeLength := layerLen%2 == 1
+		if oddNodeLength {
+			zerohash := trie.ZeroHashes[i]
+			elements = append(elements, zerohash)
+		}
+
+		levelBaseGindex := subtreeGeneralizedIndex << (depth - i)
+		for idx := range elements {
+			gindex := levelBaseGindex + uint64(idx)
+			pc.collectSibling(gindex, elements[idx])
+			pc.collectLeaf(gindex, elements[idx])
+		}
+
+		elements = htr.VectorizedSha256(elements)
+	}
+	return elements[0]
+}
+
+// mixinLengthAndCollect computes the final mix-in root for list/bitlist values:
+//
+//	root = hash(dataRoot, lengthHash)
+//
+// where chunks[0] is dataRoot and chunks[1] is the 32-byte length hash.
+//
+// Generalized indices (gindices): dataRoot is the left child (dataRootGindex = currentGindex*2) and lengthHash is the right child (lengthHashGindex = currentGindex*2+1).
+// Proof collection: it calls collectSibling/collectLeaf for both child gindices; the collector stores them only if they were registered via addTarget.
+//
+// Parameters:
+// - currentGindex: gindex of the parent node (list/bitlist root).
+// - chunks: two 32-byte nodes: [dataRoot, lengthHash].
+//
+// Returns:
+// - [32]byte: mixed-in Merkle root (or zero value on hashing error).
+// - error: any error encountered during hashing.
+func (pc *proofCollector) mixinLengthAndCollect(currentGindex uint64, chunks [][32]byte) [32]byte {
+	dataRoot, lengthHash := chunks[0], chunks[1]
+	dataRootGindex, lengthHashGindex := currentGindex*2, currentGindex*2+1
+
+	pc.collectSibling(dataRootGindex, dataRoot)
+	pc.collectSibling(lengthHashGindex, lengthHash)
+
+	pc.collectLeaf(dataRootGindex, dataRoot)
+	pc.collectLeaf(lengthHashGindex, lengthHash)
+
+	return ssz.MixInLength(dataRoot, lengthHash[:])
+}

encoding/ssz/query/proof_collector_test.go

@@ -0,0 +1,531 @@
+package query
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"reflect"
+	"slices"
+	"testing"
+
+	"github.com/OffchainLabs/go-bitfield"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/state/stateutil"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
+	ssz "github.com/OffchainLabs/prysm/v7/encoding/ssz"
+	ethpb "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
+	sszquerypb "github.com/OffchainLabs/prysm/v7/proto/ssz_query/testing"
+	"github.com/OffchainLabs/prysm/v7/testing/require"
+)
+
+func TestProofCollector_New(t *testing.T) {
+	pc := newProofCollector()
+
+	require.NotNil(t, pc)
+	require.Equal(t, 0, len(pc.requiredSiblings))
+	require.Equal(t, 0, len(pc.requiredLeaves))
+	require.Equal(t, 0, len(pc.siblings))
+	require.Equal(t, 0, len(pc.leaves))
+}
+
+func TestProofCollector_Reset(t *testing.T) {
+	pc := newProofCollector()
+	pc.requiredSiblings[3] = struct{}{}
+	pc.requiredLeaves[5] = struct{}{}
+	pc.siblings[3] = [32]byte{1}
+	pc.leaves[5] = [32]byte{2}
+
+	pc.reset()
+
+	require.Equal(t, 0, len(pc.requiredSiblings))
+	require.Equal(t, 0, len(pc.requiredLeaves))
+	require.Equal(t, 0, len(pc.siblings))
+	require.Equal(t, 0, len(pc.leaves))
+}
+
+func TestProofCollector_AddTarget(t *testing.T) {
+	pc := newProofCollector()
+	pc.addTarget(5)
+
+	_, hasLeaf := pc.requiredLeaves[5]
+	_, hasSibling4 := pc.requiredSiblings[4]
+	_, hasSibling3 := pc.requiredSiblings[3]
+	_, hasSibling1 := pc.requiredSiblings[1] // GI 1 is the root
+
+	require.Equal(t, true, hasLeaf)
+	require.Equal(t, true, hasSibling4)
+	require.Equal(t, true, hasSibling3)
+	require.Equal(t, false, hasSibling1)
+}
+
+func TestProofCollector_ToProof(t *testing.T) {
+	pc := newProofCollector()
+	pc.addTarget(5)
+
+	leaf := [32]byte{9}
+	sibling4 := [32]byte{4}
+	sibling3 := [32]byte{3}
+
+	pc.collectLeaf(5, leaf)
+	pc.collectSibling(4, sibling4)
+	pc.collectSibling(3, sibling3)
+
+	proof, err := pc.toProof()
+	require.NoError(t, err)
+
+	require.Equal(t, 5, proof.Index)
+	require.DeepEqual(t, leaf[:], proof.Leaf)
+	require.Equal(t, 2, len(proof.Hashes))
+	require.DeepEqual(t, sibling4[:], proof.Hashes[0])
+	require.DeepEqual(t, sibling3[:], proof.Hashes[1])
+}
+
+func TestProofCollector_ToProof_NoLeaves(t *testing.T) {
+	pc := newProofCollector()
+	_, err := pc.toProof()
+	require.NotNil(t, err)
+}
+
+func TestProofCollector_CollectLeaf(t *testing.T) {
+	pc := newProofCollector()
+	leaf := [32]byte{7}
+
+	pc.collectLeaf(10, leaf)
+	require.Equal(t, 0, len(pc.leaves))
+
+	pc.addTarget(10)
+	pc.collectLeaf(10, leaf)
+	stored, ok := pc.leaves[10]
+	require.Equal(t, true, ok)
+	require.Equal(t, leaf, stored)
+}
+
+func TestProofCollector_CollectSibling(t *testing.T) {
+	pc := newProofCollector()
+	hash := [32]byte{5}
+
+	pc.collectSibling(4, hash)
+	require.Equal(t, 0, len(pc.siblings))
+
+	pc.addTarget(5)
+	pc.collectSibling(4, hash)
+	stored, ok := pc.siblings[4]
+	require.Equal(t, true, ok)
+	require.Equal(t, hash, stored)
+}
+
+func TestProofCollector_Merkleize_BasicTypes(t *testing.T) {
+	testCases := []struct {
+		name     string
+		sszType  SSZType
+		value    any
+		expected [32]byte
+	}{
+		{
+			name:    "uint8",
+			sszType: Uint8,
+			value:   uint8(0x11),
+			expected: func() [32]byte {
+				var leaf [32]byte
+				leaf[0] = 0x11
+				return leaf
+			}(),
+		},
+		{
+			name:    "uint16",
+			sszType: Uint16,
+			value:   uint16(0x2211),
+			expected: func() [32]byte {
+				var leaf [32]byte
+				binary.LittleEndian.PutUint16(leaf[:2], 0x2211)
+				return leaf
+			}(),
+		},
+		{
+			name:    "uint32",
+			sszType: Uint32,
+			value:   uint32(0x44332211),
+			expected: func() [32]byte {
+				var leaf [32]byte
+				binary.LittleEndian.PutUint32(leaf[:4], 0x44332211)
+				return leaf
+			}(),
+		},
+		{
+			name:    "uint64",
+			sszType: Uint64,
+			value:   uint64(0x8877665544332211),
+			expected: func() [32]byte {
+				var leaf [32]byte
+				binary.LittleEndian.PutUint64(leaf[:8], 0x8877665544332211)
+				return leaf
+			}(),
+		},
+		{
+			name:    "bool",
+			sszType: Boolean,
+			value:   true,
+			expected: func() [32]byte {
+				var leaf [32]byte
+				leaf[0] = 1
+				return leaf
+			}(),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			pc := newProofCollector()
+			gindex := uint64(3)
+			pc.addTarget(gindex)
+
+			leaf, err := pc.merkleizeBasicType(tc.sszType, reflect.ValueOf(tc.value), gindex)
+			require.NoError(t, err)
+			require.Equal(t, tc.expected, leaf)
+
+			stored, ok := pc.leaves[gindex]
+			require.Equal(t, true, ok)
+			require.Equal(t, tc.expected, stored)
+		})
+	}
+}
+
+func TestProofCollector_Merkleize_Container(t *testing.T) {
+	container := makeFixedTestContainer()
+
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	pc := newProofCollector()
+	pc.addTarget(1)
+
+	root, err := pc.merkleize(info, reflect.ValueOf(container), 1)
+	require.NoError(t, err)
+
+	expected, err := container.HashTreeRoot()
+	require.NoError(t, err)
+	require.Equal(t, expected, root)
+
+	stored, ok := pc.leaves[1]
+	require.Equal(t, true, ok)
+	require.Equal(t, expected, stored)
+}
+
+func TestProofCollector_Merkleize_Vector(t *testing.T) {
+	container := makeFixedTestContainer()
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	ci, err := info.ContainerInfo()
+	require.NoError(t, err)
+	field := ci.fields["vector_field"]
+
+	pc := newProofCollector()
+	root, err := pc.merkleizeVector(field.sszInfo, reflect.ValueOf(container.VectorField), 1)
+	require.NoError(t, err)
+
+	serialized := make([][]byte, len(container.VectorField))
+	for i, v := range container.VectorField {
+		buf := make([]byte, 8)
+		binary.LittleEndian.PutUint64(buf, v)
+		serialized[i] = buf
+	}
+	chunks, err := ssz.PackByChunk(serialized)
+	require.NoError(t, err)
+	limit, err := getChunkCount(field.sszInfo)
+	require.NoError(t, err)
+	expected := ssz.MerkleizeVector(chunks, limit)
+
+	require.Equal(t, expected, root)
+}
+
+func TestProofCollector_Merkleize_List(t *testing.T) {
+	list := []*sszquerypb.FixedNestedContainer{
+		makeFixedNestedContainer(1),
+		makeFixedNestedContainer(2),
+	}
+	container := makeVariableTestContainer(list, bitfield.NewBitlist(1))
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	ci, err := info.ContainerInfo()
+	require.NoError(t, err)
+	field := ci.fields["field_list_container"]
+
+	pc := newProofCollector()
+	root, err := pc.merkleizeList(field.sszInfo, reflect.ValueOf(list), 1)
+	require.NoError(t, err)
+
+	listInfo, err := field.sszInfo.ListInfo()
+	require.NoError(t, err)
+	expected, err := ssz.MerkleizeListSSZ(list, listInfo.Limit())
+	require.NoError(t, err)
+
+	require.Equal(t, expected, root)
+}
+
+func TestProofCollector_Merkleize_Bitvector(t *testing.T) {
+	container := makeFixedTestContainer()
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	ci, err := info.ContainerInfo()
+	require.NoError(t, err)
+	field := ci.fields["bitvector64_field"]
+
+	pc := newProofCollector()
+	root, err := pc.merkleizeBitvector(field.sszInfo, reflect.ValueOf(container.Bitvector64Field), 1)
+	require.NoError(t, err)
+
+	expected, err := ssz.MerkleizeByteSliceSSZ([]byte(container.Bitvector64Field))
+	require.NoError(t, err)
+	require.Equal(t, expected, root)
+}
+
+func TestProofCollector_Merkleize_Bitlist(t *testing.T) {
+	bitlist := bitfield.NewBitlist(16)
+	bitlist.SetBitAt(3, true)
+	bitlist.SetBitAt(8, true)
+
+	container := makeVariableTestContainer(nil, bitlist)
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	ci, err := info.ContainerInfo()
+	require.NoError(t, err)
+	field := ci.fields["bitlist_field"]
+
+	pc := newProofCollector()
+	root, err := pc.merkleizeBitlist(field.sszInfo, reflect.ValueOf(container.BitlistField), 1)
+	require.NoError(t, err)
+
+	bitlistInfo, err := field.sszInfo.BitlistInfo()
+	require.NoError(t, err)
+	expected, err := ssz.BitlistRoot(bitfield.Bitlist(bitlist), bitlistInfo.Limit())
+	require.NoError(t, err)
+	require.Equal(t, expected, root)
+}
+
+func TestProofCollector_MerkleizeVectorBody_Basic(t *testing.T) {
+	container := makeFixedTestContainer()
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	ci, err := info.ContainerInfo()
+	require.NoError(t, err)
+	field := ci.fields["vector_field"]
+	vectorInfo, err := field.sszInfo.VectorInfo()
+	require.NoError(t, err)
+	length := len(container.VectorField)
+	limit, err := getChunkCount(field.sszInfo)
+	require.NoError(t, err)
+
+	pc := newProofCollector()
+	root, err := pc.merkleizeVectorBody(vectorInfo.element, reflect.ValueOf(container.VectorField), length, limit, 2)
+	require.NoError(t, err)
+
+	serialized := make([][]byte, len(container.VectorField))
+	for i, v := range container.VectorField {
+		buf := make([]byte, 8)
+		binary.LittleEndian.PutUint64(buf, v)
+		serialized[i] = buf
+	}
+	chunks, err := ssz.PackByChunk(serialized)
+	require.NoError(t, err)
+	expected := ssz.MerkleizeVector(chunks, limit)
+
+	require.Equal(t, expected, root)
+}
+
+func TestProofCollector_MerkleizeVectorAndCollect(t *testing.T) {
+	pc := newProofCollector()
+	pc.addTarget(6)
+
+	elements := [][32]byte{{1}, {2}}
+	expected := ssz.MerkleizeVector(slices.Clone(elements), 2)
+	root := pc.merkleizeVectorAndCollect(elements, 3, 1)
+
+	storedLeaf, hasLeaf := pc.leaves[6]
+	storedSibling, hasSibling := pc.siblings[7]
+
+	require.Equal(t, true, hasLeaf)
+	require.Equal(t, true, hasSibling)
+	require.Equal(t, elements[0], storedLeaf)
+	require.Equal(t, elements[1], storedSibling)
+
+	require.Equal(t, expected, root)
+}
+
+func TestProofCollector_MixinLengthAndCollect(t *testing.T) {
+	list := []*sszquerypb.FixedNestedContainer{
+		makeFixedNestedContainer(1),
+		makeFixedNestedContainer(2),
+	}
+	container := makeVariableTestContainer(list, bitfield.NewBitlist(1))
+	info, err := AnalyzeObject(container)
+	require.NoError(t, err)
+
+	ci, err := info.ContainerInfo()
+	require.NoError(t, err)
+	field := ci.fields["field_list_container"]
+
+	// Target gindex 2 (data root) - sibling at gindex 3 (length hash) should be collected
+	pc := newProofCollector()
+	pc.addTarget(2)
+	root, err := pc.merkleizeList(field.sszInfo, reflect.ValueOf(list), 1)
+	require.NoError(t, err)
+
+	listInfo, err := field.sszInfo.ListInfo()
+	require.NoError(t, err)
+	expected, err := ssz.MerkleizeListSSZ(list, listInfo.Limit())
+	require.NoError(t, err)
+	require.Equal(t, expected, root)
+
+	// Verify data root is collected as leaf at gindex 2
+	storedLeaf, hasLeaf := pc.leaves[2]
+	require.Equal(t, true, hasLeaf)
+
+	// Verify length hash is collected as sibling at gindex 3
+	storedSibling, hasSibling := pc.siblings[3]
+	require.Equal(t, true, hasSibling)
+
+	// Verify the root is hash(dataRoot || lengthHash)
+	expectedBuf := append(storedLeaf[:], storedSibling[:]...)
+	expectedRoot := sha256.Sum256(expectedBuf)
+	require.Equal(t, expectedRoot, root)
+}
+
+func BenchmarkOptimizedValidatorRoots(b *testing.B) {
+	validators := make([]*ethpb.Validator, 1000)
+	for i := range validators {
+		validators[i] = makeTestValidator(i)
+	}
+
+	b.ResetTimer()
+	for b.Loop() {
+		_, err := stateutil.OptimizedValidatorRoots(validators)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkProofCollectorMerkleize(b *testing.B) {
+	validators := make([]*ethpb.Validator, 1000)
+	for i := range validators {
+		validators[i] = makeTestValidator(i)
+	}
+
+	info, err := AnalyzeObject(validators[0])
+	require.NoError(b, err)
+
+	b.ResetTimer()
+	for b.Loop() {
+		for _, val := range validators {
+			pc := newProofCollector()
+			v := reflect.ValueOf(val)
+			_, err := pc.merkleize(info, v, 1)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+	}
+}
+
+func makeTestValidator(i int) *ethpb.Validator {
+	pubkey := make([]byte, 48)
+	for j := range pubkey {
+		pubkey[j] = byte(i + j)
+	}
+
+	withdrawalCredentials := make([]byte, 32)
+	for j := range withdrawalCredentials {
+		withdrawalCredentials[j] = byte(255 - ((i + j) % 256))
+	}
+
+	return &ethpb.Validator{
+		PublicKey:                  pubkey,
+		WithdrawalCredentials:      withdrawalCredentials,
+		EffectiveBalance:           uint64(32000000000 + i),
+		Slashed:                    i%2 == 0,
+		ActivationEligibilityEpoch: primitives.Epoch(i),
+		ActivationEpoch:            primitives.Epoch(i + 1),
+		ExitEpoch:                  primitives.Epoch(i + 2),
+		WithdrawableEpoch:          primitives.Epoch(i + 3),
+	}
+}
+
+func makeFixedNestedContainer(value uint64) *sszquerypb.FixedNestedContainer {
+	value2 := make([]byte, 32)
+	for i := range value2 {
+		value2[i] = byte(i)
+	}
+	return &sszquerypb.FixedNestedContainer{
+		Value1: value,
+		Value2: value2,
+	}
+}
+
+func makeFixedTestContainer() *sszquerypb.FixedTestContainer {
+	fieldBytes32 := make([]byte, 32)
+	for i := range fieldBytes32 {
+		fieldBytes32[i] = byte(i)
+	}
+
+	vectorField := make([]uint64, 24)
+	for i := range vectorField {
+		vectorField[i] = uint64(i)
+	}
+
+	rows := make([][]byte, 5)
+	for i := range rows {
+		row := make([]byte, 32)
+		for j := range row {
+			row[j] = byte(i) + byte(j)
+		}
+		rows[i] = row
+	}
+
+	bitvector64 := bitfield.NewBitvector64()
+	bitvector64.SetBitAt(1, true)
+	bitvector512 := bitfield.NewBitvector512()
+	bitvector512.SetBitAt(10, true)
+
+	trailing := make([]byte, 56)
+	for i := range trailing {
+		trailing[i] = byte(i)
+	}
+
+	return &sszquerypb.FixedTestContainer{
+		FieldUint32:            1,
+		FieldUint64:            2,
+		FieldBool:              true,
+		FieldBytes32:           fieldBytes32,
+		Nested:                 makeFixedNestedContainer(3),
+		VectorField:            vectorField,
+		TwoDimensionBytesField: rows,
+		Bitvector64Field:       bitvector64,
+		Bitvector512Field:      bitvector512,
+		TrailingField:          trailing,
+	}
+}
+
+func makeVariableTestContainer(list []*sszquerypb.FixedNestedContainer, bitlist bitfield.Bitlist) *sszquerypb.VariableTestContainer {
+	leading := make([]byte, 32)
+	for i := range leading {
+		leading[i] = byte(i)
+	}
+	trailing := make([]byte, 56)
+	for i := range trailing {
+		trailing[i] = byte(255 - i)
+	}
+
+	if bitlist == nil {
+		bitlist = bitfield.NewBitlist(0)
+	}
+
+	return &sszquerypb.VariableTestContainer{
+		LeadingField:       leading,
+		FieldListContainer: list,
+		BitlistField:       bitlist,
+		TrailingField:      trailing,
+	}
+}

encoding/ssz/query/query_test.go

@@ -389,6 +389,7 @@ func TestHashTreeRoot(t *testing.T) {
 			require.NoError(t, err, "HashTreeRoot should not return an error")
 			expectedHashTreeRoot, err := tt.obj.HashTreeRoot()
 			require.NoError(t, err, "HashTreeRoot on original object should not return an error")
+			// Verify the Merkle tree root matches with the SSZ generated HashTreeRoot
 			require.Equal(t, expectedHashTreeRoot, hashTreeRoot, "HashTreeRoot from sszInfo should match original object's HashTreeRoot")
 		})
 	}

io/logs/logutil.go

@@ -103,7 +103,7 @@ func ConfigureEphemeralLogFile(datadirPath string, app string) error {
 		AllowedLevels: logrus.AllLevels[:ephemeralLogFileVerbosity+1],
 	})
 
-	logrus.Debug("Ephemeral log file initialized")
+	logrus.WithField("path", logFilePath).Debug("Ephemeral log file initialized")
 	return nil
 }
 

testing/endtoend/BUILD.bazel

@@ -97,6 +97,7 @@ go_test(
         "endtoend_setup_test.go",
         "endtoend_test.go",
         "minimal_e2e_test.go",
+        "minimal_hdiff_e2e_test.go",
         "minimal_slashing_e2e_test.go",
         "slasher_simulator_e2e_test.go",
     ],

testing/endtoend/minimal_hdiff_e2e_test.go

@@ -0,0 +1,16 @@
+package endtoend
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v7/config/params"
+	"github.com/OffchainLabs/prysm/v7/runtime/version"
+	"github.com/OffchainLabs/prysm/v7/testing/endtoend/types"
+)
+
+func TestEndToEnd_MinimalConfig_WithStateDiff(t *testing.T) {
+	r := e2eMinimal(t, types.InitForkCfg(version.Bellatrix, version.Electra, params.E2ETestConfig()),
+		types.WithStateDiff(),
+	)
+	r.run()
+}

testing/endtoend/types/types.go

@@ -76,6 +76,15 @@ func WithSSZOnly() E2EConfigOpt {
 	}
 }
 
+func WithStateDiff() E2EConfigOpt {
+	return func(cfg *E2EConfig) {
+		cfg.BeaconFlags = append(cfg.BeaconFlags,
+			"--enable-state-diff",
+			"--state-diff-exponents=6,5", // Small exponents for quick testing
+		)
+	}
+}
+
 // WithExitEpoch sets a custom epoch for voluntary exit submission.
 // This affects ProposeVoluntaryExit, ValidatorsHaveExited, SubmitWithdrawal, and ValidatorsHaveWithdrawn evaluators.
 func WithExitEpoch(e primitives.Epoch) E2EConfigOpt {

third_party/com_github_offchainlabs_hashtree.patch

@@ -1,7 +1,7 @@
 diff -urN a/BUILD.bazel b/BUILD.bazel
 --- a/BUILD.bazel	1969-12-31 18:00:00.000000000 -0600
 +++ b/BUILD.bazel	2025-01-05 12:00:00.000000000 -0600
-@@ -0,0 +1,89 @@
+@@ -0,0 +1,90 @@
 +load("@io_bazel_rules_go//go:def.bzl", "go_library")
 +
 +go_library(
@@ -32,6 +32,7 @@ diff -urN a/BUILD.bazel b/BUILD.bazel
 +        ],
 +        "@io_bazel_rules_go//go/platform:darwin_amd64": [
 +            "bindings_darwin_amd64.go",
++            "wrapper_darwin_amd64.s",
 +        ],
 +        "//conditions:default": [],
 +    }),

validator/client/aggregate.go

@@ -66,7 +66,7 @@ func (v *validator) SubmitAggregateAndProof(ctx context.Context, slot primitives
 	// As specified in spec, an aggregator should wait until two thirds of the way through slot
 	// to broadcast the best aggregate to the global aggregate channel.
 	// https://github.com/ethereum/consensus-specs/blob/v0.9.3/specs/validator/0_beacon-chain-validator.md#broadcast-aggregate
-	v.waitToSlotTwoThirds(ctx, slot)
+	v.waitUntilAggregateDue(ctx, slot)
 
 	// In a DV setup, selection proofs need to be agreed upon by the DV.
 	// Checking for selection proofs at slot 0 of the epoch will result in an error, as the call to the DV executes slower than the start of this function.
@@ -203,11 +203,18 @@ func (v *validator) signSlotWithSelectionProof(ctx context.Context, pubKey [fiel
 	return sig.Marshal(), nil
 }
 
-// waitToSlotTwoThirds waits until two third through the current slot period
-// such that any attestations from this slot have time to reach the beacon node
-// before creating the aggregated attestation.
-func (v *validator) waitToSlotTwoThirds(ctx context.Context, slot primitives.Slot) {
-	v.waitUntilSlotComponent(ctx, slot, params.BeaconConfig().AggregateDueBPS)
+// waitUntilAggregateDue waits until the configured aggregation due time within the current slot
+// such that any attestations from this slot have time to reach the beacon node before creating
+// the aggregated attestation.
+//
+// Note: Historically this was ~2/3 of the slot, but may differ across forks (e.g. Gloas).
+func (v *validator) waitUntilAggregateDue(ctx context.Context, slot primitives.Slot) {
+	cfg := params.BeaconConfig()
+	component := cfg.AggregateDueBPS
+	if slots.ToEpoch(slot) >= cfg.GloasForkEpoch {
+		component = cfg.AggregateDueBPSGloas
+	}
+	v.waitUntilSlotComponent(ctx, slot, component)
 }
 
 // This returns the signature of validator signing over aggregate and

validator/client/aggregate_test.go

@@ -260,7 +260,7 @@ func TestWaitForSlotTwoThird_WaitCorrectly(t *testing.T) {
 			timeToSleep := params.BeaconConfig().SlotComponentDuration(params.BeaconConfig().AggregateDueBPS)
 
 			twoThirdTime := currentTime.Add(timeToSleep)
-			validator.waitToSlotTwoThirds(t.Context(), numOfSlots)
+			validator.waitUntilAggregateDue(t.Context(), numOfSlots)
 			currentTime = time.Now()
 			assert.Equal(t, twoThirdTime.Unix(), currentTime.Unix())
 		})
@@ -280,7 +280,7 @@ func TestWaitForSlotTwoThird_DoneContext_ReturnsImmediately(t *testing.T) {
 			expectedTime := time.Now()
 			ctx, cancel := context.WithCancel(t.Context())
 			cancel()
-			validator.waitToSlotTwoThirds(ctx, numOfSlots)
+			validator.waitUntilAggregateDue(ctx, numOfSlots)
 			currentTime = time.Now()
 			assert.Equal(t, expectedTime.Unix(), currentTime.Unix())
 		})

validator/client/attest.go

@@ -37,7 +37,7 @@ func (v *validator) SubmitAttestation(ctx context.Context, slot primitives.Slot,
 	defer span.End()
 	span.SetAttributes(trace.StringAttribute("validator", fmt.Sprintf("%#x", pubKey)))
 
-	v.waitOneThirdOrValidBlock(ctx, slot)
+	v.waitUntilAttestationDueOrValidBlock(ctx, slot)
 
 	var b strings.Builder
 	if err := b.WriteByte(byte(iface.RoleAttester)); err != nil {
@@ -259,12 +259,12 @@ func (v *validator) setHighestSlot(slot primitives.Slot) {
 	}
 }
 
-// waitOneThirdOrValidBlock waits until (a) or (b) whichever comes first:
+// waitUntilAttestationDueOrValidBlock waits until (a) or (b) whichever comes first:
 //
 //	(a) the validator has received a valid block that is the same slot as input slot
-//	(b) one-third of the slot has transpired (SECONDS_PER_SLOT / 3 seconds after the start of slot)
-func (v *validator) waitOneThirdOrValidBlock(ctx context.Context, slot primitives.Slot) {
-	ctx, span := trace.StartSpan(ctx, "validator.waitOneThirdOrValidBlock")
+//	(b) the configured attestation due time has transpired (as basis points of the slot duration)
+func (v *validator) waitUntilAttestationDueOrValidBlock(ctx context.Context, slot primitives.Slot) {
+	ctx, span := trace.StartSpan(ctx, "validator.waitUntilAttestationDueOrValidBlock")
 	defer span.End()
 
 	// Don't need to wait if requested slot is the same as highest valid slot.
@@ -272,7 +272,12 @@ func (v *validator) waitOneThirdOrValidBlock(ctx context.Context, slot primitive
 		return
 	}
 
-	finalTime, err := v.slotComponentDeadline(slot, params.BeaconConfig().AttestationDueBPS)
+	cfg := params.BeaconConfig()
+	component := cfg.AttestationDueBPS
+	if slots.ToEpoch(slot) >= cfg.GloasForkEpoch {
+		component = cfg.AttestationDueBPSGloas
+	}
+	finalTime, err := v.slotComponentDeadline(slot, component)
 	if err != nil {
 		log.WithError(err).WithField("slot", slot).Error("Slot overflows, unable to wait for attestation deadline")
 		return

validator/client/attest_test.go

@@ -706,7 +706,7 @@ func TestServer_WaitToSlotOneThird_CanWait(t *testing.T) {
 
 	timeToSleep := params.BeaconConfig().SecondsPerSlot / 3
 	oneThird := currentTime.Add(time.Duration(timeToSleep) * time.Second)
-	v.waitOneThirdOrValidBlock(t.Context(), currentSlot)
+	v.waitUntilAttestationDueOrValidBlock(t.Context(), currentSlot)
 
 	if oneThird.Sub(time.Now()) > 10*time.Millisecond { // Allow for small diff due to execution time.
 		t.Errorf("Wanted %s time for slot one third but got %s", oneThird, currentTime)
@@ -724,7 +724,7 @@ func TestServer_WaitToSlotOneThird_SameReqSlot(t *testing.T) {
 		highestValidSlot: currentSlot,
 	}
 
-	v.waitOneThirdOrValidBlock(t.Context(), currentSlot)
+	v.waitUntilAttestationDueOrValidBlock(t.Context(), currentSlot)
 
 	if currentTime.Sub(time.Now()) > 10*time.Millisecond { // Allow for small diff due to execution time.
 		t.Errorf("Wanted %s time for slot one third but got %s", time.Now(), currentTime)
@@ -750,7 +750,7 @@ func TestServer_WaitToSlotOneThird_ReceiveBlockSlot(t *testing.T) {
 		v.slotFeed.Send(currentSlot)
 	})
 
-	v.waitOneThirdOrValidBlock(t.Context(), currentSlot)
+	v.waitUntilAttestationDueOrValidBlock(t.Context(), currentSlot)
 
 	if currentTime.Sub(time.Now()) > 10*time.Millisecond { // Allow for small diff due to execution time.
 		t.Errorf("Wanted %s time for slot one third but got %s", time.Now(), currentTime)

validator/client/sync_committee.go

@@ -29,7 +29,7 @@ func (v *validator) SubmitSyncCommitteeMessage(ctx context.Context, slot primiti
 	defer span.End()
 	span.SetAttributes(trace.StringAttribute("validator", fmt.Sprintf("%#x", pubKey)))
 
-	v.waitOneThirdOrValidBlock(ctx, slot)
+	v.waitUntilAttestationDueOrValidBlock(ctx, slot)
 
 	res, err := v.validatorClient.SyncMessageBlockRoot(ctx, &emptypb.Empty{})
 	if err != nil {
@@ -127,7 +127,12 @@ func (v *validator) SubmitSignedContributionAndProof(ctx context.Context, slot p
 		return
 	}
 
-	v.waitUntilSlotComponent(ctx, slot, params.BeaconConfig().ContributionDueBPS)
+	cfg := params.BeaconConfig()
+	component := cfg.ContributionDueBPS
+	if slots.ToEpoch(slot) >= cfg.GloasForkEpoch {
+		component = cfg.ContributionDueBPSGloas
+	}
+	v.waitUntilSlotComponent(ctx, slot, component)
 
 	coveredSubnets := make(map[uint64]bool)
 	for i, comIdx := range indexRes.Indices {

validator/client/wait_helpers.go

@@ -51,12 +51,20 @@ func (v *validator) slotComponentSpanName(component primitives.BP) string {
 	switch component {
 	case cfg.AttestationDueBPS:
 		return "validator.waitAttestationWindow"
+	case cfg.AttestationDueBPSGloas:
+		return "validator.waitAttestationWindow"
 	case cfg.AggregateDueBPS:
 		return "validator.waitAggregateWindow"
+	case cfg.AggregateDueBPSGloas:
+		return "validator.waitAggregateWindow"
 	case cfg.SyncMessageDueBPS:
 		return "validator.waitSyncMessageWindow"
+	case cfg.SyncMessageDueBPSGloas:
+		return "validator.waitSyncMessageWindow"
 	case cfg.ContributionDueBPS:
 		return "validator.waitContributionWindow"
+	case cfg.ContributionDueBPSGloas:
+		return "validator.waitContributionWindow"
 	case cfg.ProposerReorgCutoffBPS:
 		return "validator.waitProposerReorgWindow"
 	default: