ChainSafe · wemeetagain · May 20, 2026 · May 21, 2026 · May 21, 2026 · May 22, 2026
@@ -43,6 +43,7 @@
     "@biomejs/biome": "^2.2.0",
     "@chainsafe/benchmark": "^2.0.2",
     "@chainsafe/biomejs-config": "^1.0.0",
+    "@chainsafe/ssz": "^1.6.0",
     "@lerna-lite/cli": "^4.9.4",
     "@lerna-lite/exec": "^4.9.4",
     "@lerna-lite/publish": "^4.9.4",

@@ -74,8 +74,8 @@
     "check-readme": "pnpm exec ts-node ../../scripts/check_readme.ts"
   },
   "dependencies": {
-    "@chainsafe/persistent-merkle-tree": "^1.2.5",
-    "@chainsafe/ssz": "^1.4.0",
+    "@chainsafe/persistent-merkle-tree": "^1.3.0",
+    "@chainsafe/ssz": "^1.6.0",
     "@lodestar/config": "workspace:^",
     "@lodestar/params": "workspace:^",
     "@lodestar/types": "workspace:^",

@@ -114,11 +114,11 @@
     "@chainsafe/enr": "^6.0.1",
     "@chainsafe/libp2p-noise": "^17.0.0",
     "@chainsafe/libp2p-quic": "^2.0.1",
-    "@chainsafe/persistent-merkle-tree": "^1.2.5",
+    "@chainsafe/persistent-merkle-tree": "^1.3.0",
     "@chainsafe/prometheus-gc-stats": "^1.0.0",
     "@chainsafe/pubkey-index-map": "^3.0.0",
     "@chainsafe/snappy-wasm": "^0.5.0",
-    "@chainsafe/ssz": "^1.4.0",
+    "@chainsafe/ssz": "^1.6.0",
     "@chainsafe/threads": "^1.11.3",
     "@crate-crypto/node-eth-kzg": "0.9.1",
     "@fastify/bearer-auth": "^10.0.1",

@@ -74,7 +74,7 @@ export function verifyExecutionPayloadEnvelope(
   // Verify execution_requests_root matches bid commitment.
   // Can be skipped if already verified during gossip validation.
   if (verifyExecutionRequestsRoot) {
-    const requestsRoot = ssz.electra.ExecutionRequests.hashTreeRoot(envelope.executionRequests);
+    const requestsRoot = ssz.gloas.ExecutionRequests.hashTreeRoot(envelope.executionRequests);
     if (!byteArrayEquals(requestsRoot, bid.executionRequestsRoot)) {
       throw new Error(
         `Execution requests root mismatch envelope=${toRootHex(requestsRoot)} bid=${toRootHex(bid.executionRequestsRoot)}`
@@ -102,8 +102,8 @@ export function verifyExecutionPayloadEnvelope(
   }
 
   // Verify consistency with expected withdrawals
-  const payloadWithdrawalsRoot = ssz.capella.Withdrawals.hashTreeRoot(payload.withdrawals);
-  const expectedWithdrawalsRoot = ssz.capella.Withdrawals.hashTreeRoot(state.payloadExpectedWithdrawals);
+  const payloadWithdrawalsRoot = ssz.gloas.Withdrawals.hashTreeRoot(payload.withdrawals);
+  const expectedWithdrawalsRoot = ssz.gloas.Withdrawals.hashTreeRoot(state.payloadExpectedWithdrawals);
   if (!byteArrayEquals(payloadWithdrawalsRoot, expectedWithdrawalsRoot)) {
     throw new Error(
       `Withdrawals mismatch between payload and expected payload=${toRootHex(payloadWithdrawalsRoot)} expected=${toRootHex(expectedWithdrawalsRoot)}`

@@ -40,7 +40,6 @@ import {
   ValidatorIndex,
   Wei,
   deneb,
-  electra,
   gloas,
   isBlindedBeaconBlock,
   phase0,
@@ -916,10 +915,10 @@ export class BeaconChain implements IBeaconChain {
   async getParentExecutionRequests(
     parentBlockSlot: Slot,
     parentBlockRootHex: RootHex
-  ): Promise<electra.ExecutionRequests> {
+  ): Promise<gloas.ExecutionRequests> {
     // at the fork boundary, parent is pre-gloas
     if (!isForkPostGloas(this.config.getForkName(parentBlockSlot))) {
-      return ssz.electra.ExecutionRequests.defaultValue();
+      return ssz.gloas.ExecutionRequests.defaultValue();
     }
     const envelope = await this.getExecutionPayloadEnvelope(parentBlockSlot, parentBlockRootHex);
     if (envelope === null) {

@@ -18,7 +18,6 @@ import {
   altair,
   capella,
   deneb,
-  electra,
   gloas,
   phase0,
   rewards,
@@ -236,7 +235,7 @@ export interface IBeaconChain {
     blockSlot: Slot,
     blockRootHex: string
   ): Promise<gloas.SignedExecutionPayloadEnvelope | null>;
-  getParentExecutionRequests(parentBlockSlot: Slot, parentBlockRootHex: RootHex): Promise<electra.ExecutionRequests>;
+  getParentExecutionRequests(parentBlockSlot: Slot, parentBlockRootHex: RootHex): Promise<gloas.ExecutionRequests>;
 
   produceCommonBlockBody(blockAttributes: BlockAttributes): Promise<CommonBlockBody>;
   produceBlock(blockAttributes: BlockAttributes & {commonBlockBodyPromise: Promise<CommonBlockBody>}): Promise<{

@@ -10,9 +10,8 @@ import {
   MIN_SYNC_COMMITTEE_PARTICIPANTS,
   SLOTS_PER_EPOCH,
   SYNC_COMMITTEE_SIZE,
-  forkPostAltair,
-  highestFork,
   isForkPostElectra,
+  isForkPostGloas,
 } from "@lodestar/params";
 import {
   type IBeaconStateViewAltair,
@@ -44,7 +43,6 @@ import {
   electra,
   phase0,
   ssz,
-  sszTypesFor,
 } from "@lodestar/types";
 import {Logger, MapDef, byteArrayEquals, pruneSetToMax, toRootHex} from "@lodestar/utils";
 import {ZERO_HASH} from "../../constants/index.js";
@@ -230,8 +228,8 @@ export class LightClientServer {
     this.signal = signal;
 
     this.zero = {
-      // Assign the hightest fork's default value because it can always be typecasted down to correct fork
-      finalizedHeader: sszTypesFor(highestFork(forkPostAltair)).LightClientHeader.defaultValue(),
+      // Assign the highest pre-Gloas light-client header because post-Gloas light-client updates are skipped for now.
+      finalizedHeader: ssz.electra.LightClientHeader.defaultValue(),
-      finalizedHeader: ssz.electra.LightClientHeader.defaultValue(),
+      finalizedHeader: ssz.gloas.LightClientHeader.defaultValue(),
-      finalizedHeader: ssz.electra.LightClientHeader.defaultValue(),
+      finalizedHeader: ssz.gloas.LightClientHeader.defaultValue(),
       // Electra finalityBranch has fixed length of 5 whereas altair has 4. The fifth element will be ignored
       // when serializing as altair LightClientUpdate
       finalityBranch: ssz.electra.LightClientUpdate.fields.finalityBranch.defaultValue(),
@@ -658,10 +656,17 @@ export class LightClientServer {
 
     const attestedFork = this.config.getForkName(attestedHeader.beacon.slot);
     const numWitness = syncCommitteeWitness.witness.length;
-    if (isForkPostElectra(attestedFork) && numWitness !== NUM_WITNESS_ELECTRA) {
+    if (
+      isForkPostGloas(attestedFork) &&
+      (syncCommitteeWitness.currentSyncCommitteeBranch === undefined ||
+        syncCommitteeWitness.nextSyncCommitteeBranch === undefined)
+    ) {
+      throw Error("Expected post-Gloas sync committee branches");
+    }
+    if (!isForkPostGloas(attestedFork) && isForkPostElectra(attestedFork) && numWitness !== NUM_WITNESS_ELECTRA) {
       throw Error(`Expected ${NUM_WITNESS_ELECTRA} witnesses in post-Electra numWitness=${numWitness}`);
     }
-    if (!isForkPostElectra(attestedFork) && numWitness !== NUM_WITNESS) {
+    if (!isForkPostGloas(attestedFork) && !isForkPostElectra(attestedFork) && numWitness !== NUM_WITNESS) {
       throw Error(`Expected ${NUM_WITNESS} witnesses in pre-Electra numWitness=${numWitness}`);
     }
 

@@ -1,11 +1,15 @@
 import {Tree} from "@chainsafe/persistent-merkle-tree";
 import {
   BLOCK_BODY_EXECUTION_PAYLOAD_GINDEX,
+  CURRENT_SYNC_COMMITTEE_GINDEX_GLOAS,
   FINALIZED_ROOT_GINDEX,
   FINALIZED_ROOT_GINDEX_ELECTRA,
+  FINALIZED_ROOT_GINDEX_GLOAS,
   ForkName,
   ForkPostBellatrix,
+  NEXT_SYNC_COMMITTEE_GINDEX_GLOAS,
   isForkPostElectra,
+  isForkPostGloas,
 } from "@lodestar/params";
 import {BeaconStateAllForks, CachedBeaconStateAllForks} from "@lodestar/state-transition";
 import {BeaconBlockBody, SSZTypesFor, ssz} from "@lodestar/types";
@@ -17,6 +21,24 @@ export function getSyncCommitteesWitness(fork: ForkName, state: BeaconStateAllFo
   let currentSyncCommitteeRoot: Uint8Array;
   let nextSyncCommitteeRoot: Uint8Array;
 
+  if (isForkPostGloas(fork)) {
+    const tree = new Tree(state.node);
+    const currentSyncCommitteeGindex = BigInt(CURRENT_SYNC_COMMITTEE_GINDEX_GLOAS);
+    const nextSyncCommitteeGindex = BigInt(NEXT_SYNC_COMMITTEE_GINDEX_GLOAS);
+
+    currentSyncCommitteeRoot = tree.getRoot(currentSyncCommitteeGindex);
+    nextSyncCommitteeRoot = tree.getRoot(nextSyncCommitteeGindex);
+    witness = [];
+
+    return {
+      witness,
+      currentSyncCommitteeRoot,
+      nextSyncCommitteeRoot,
+      currentSyncCommitteeBranch: tree.getSingleProof(currentSyncCommitteeGindex),
+      nextSyncCommitteeBranch: tree.getSingleProof(nextSyncCommitteeGindex),
+    };
+  }
+
   if (isForkPostElectra(fork)) {
     const n2 = n1.left;
     const n5 = n2.right;
@@ -60,17 +82,30 @@ export function getSyncCommitteesWitness(fork: ForkName, state: BeaconStateAllFo
 }
 
 export function getNextSyncCommitteeBranch(syncCommitteesWitness: SyncCommitteeWitness): Uint8Array[] {
+  if (syncCommitteesWitness.nextSyncCommitteeBranch) {
+    return syncCommitteesWitness.nextSyncCommitteeBranch;
+  }
+
   // Witness branch is sorted by descending gindex
   return [syncCommitteesWitness.currentSyncCommitteeRoot, ...syncCommitteesWitness.witness];
 }
 
 export function getCurrentSyncCommitteeBranch(syncCommitteesWitness: SyncCommitteeWitness): Uint8Array[] {
+  if (syncCommitteesWitness.currentSyncCommitteeBranch) {
+    return syncCommitteesWitness.currentSyncCommitteeBranch;
+  }
+
   // Witness branch is sorted by descending gindex
   return [syncCommitteesWitness.nextSyncCommitteeRoot, ...syncCommitteesWitness.witness];
 }
 
 export function getFinalizedRootProof(state: CachedBeaconStateAllForks): Uint8Array[] {
-  const finalizedRootGindex = state.epochCtx.isPostElectra() ? FINALIZED_ROOT_GINDEX_ELECTRA : FINALIZED_ROOT_GINDEX;
+  const fork = state.config.getForkName(state.slot);
+  const finalizedRootGindex = isForkPostGloas(fork)
+    ? FINALIZED_ROOT_GINDEX_GLOAS
+    : state.epochCtx.isPostElectra()
+      ? FINALIZED_ROOT_GINDEX_ELECTRA
+      : FINALIZED_ROOT_GINDEX;
   return new Tree(state.node).getSingleProof(BigInt(finalizedRootGindex));
 }
 

@@ -26,8 +26,10 @@
  * ```
  */
 export type SyncCommitteeWitness = {
-  /** Vector[Bytes32, 4] or Vector[Bytes32, 5] depending on the fork */
+  /** Shared witness for pre-Gloas forks where current and next sync committees are siblings. */
   witness: Uint8Array[];
   currentSyncCommitteeRoot: Uint8Array;
   nextSyncCommitteeRoot: Uint8Array;
+  currentSyncCommitteeBranch?: Uint8Array[];
+  nextSyncCommitteeBranch?: Uint8Array[];
 };
@@ -108,7 +108,7 @@ export type ProduceFullGloas = {
   type: BlockType.Full;
   fork: ForkPostGloas;
   executionPayload: ExecutionPayload<ForkPostGloas>;
-  executionRequests: electra.ExecutionRequests;
+  executionRequests: gloas.ExecutionRequests;
   blobsBundle: BlobsBundle<ForkPostGloas>;
   cells: fulu.Cell[][];
   parentBlockRoot: Root;
@@ -272,7 +272,7 @@ export async function produceBlockBody<T extends BlockType>(
 
     // Get execution payload from EL
     let parentBlockHash: Bytes32;
-    let parentExecutionRequests: electra.ExecutionRequests;
+    let parentExecutionRequests: gloas.ExecutionRequests;
     // Apply parent payload once here as it's reused by EL prep and voluntary exit filtering below
     let stateAfterParentPayload: IBeaconStateViewBellatrix = currentState;
     // Spec: should_build_on_full(store, head). `parentBlock` is the proposer's head
@@ -285,7 +285,7 @@ export async function produceBlockBody<T extends BlockType>(
       stateAfterParentPayload = currentState.withParentPayloadApplied(parentExecutionRequests);
     } else {
       parentBlockHash = currentState.latestExecutionPayloadBid.parentBlockHash;
-      parentExecutionRequests = ssz.electra.ExecutionRequests.defaultValue();
+      parentExecutionRequests = ssz.gloas.ExecutionRequests.defaultValue();
     }
     const prepareRes = await prepareExecutionPayload(
       this,
@@ -350,7 +350,7 @@ export async function produceBlockBody<T extends BlockType>(
       value: 0,
       executionPayment: 0,
       blobKzgCommitments: blobsBundle.commitments,
-      executionRequestsRoot: ssz.electra.ExecutionRequests.hashTreeRoot(executionRequests),
+      executionRequestsRoot: ssz.gloas.ExecutionRequests.hashTreeRoot(executionRequests),
     };
     const signedBid: gloas.SignedExecutionPayloadBid = {
       message: bid,

@@ -108,7 +108,7 @@ async function validateExecutionPayloadEnvelope(
   }
 
   // [REJECT] `hash_tree_root(envelope.execution_requests) == bid.execution_requests_root`
-  const requestsRoot = ssz.electra.ExecutionRequests.hashTreeRoot(envelope.executionRequests);
+  const requestsRoot = ssz.gloas.ExecutionRequests.hashTreeRoot(envelope.executionRequests);
   if (!byteArrayEquals(requestsRoot, payloadInput.getBid().executionRequestsRoot)) {
     throw new ExecutionPayloadEnvelopeError(GossipAction.REJECT, {
       code: ExecutionPayloadEnvelopeErrorCode.EXECUTION_REQUESTS_ROOT_MISMATCH,

@@ -1,7 +1,7 @@
 import {BeaconConfig} from "@lodestar/config";
-import {DOMAIN_AGGREGATE_AND_PROOF, ForkSeq} from "@lodestar/params";
+import {DOMAIN_AGGREGATE_AND_PROOF} from "@lodestar/params";
 import {ISignatureSet, SignatureSetType, computeSigningRoot, computeStartSlotAtEpoch} from "@lodestar/state-transition";
-import {Epoch, SignedAggregateAndProof, ValidatorIndex, ssz} from "@lodestar/types";
+import {Epoch, SignedAggregateAndProof, ValidatorIndex} from "@lodestar/types";
 
 export function getAggregateAndProofSigningRoot(
   config: BeaconConfig,
@@ -14,7 +14,7 @@ export function getAggregateAndProofSigningRoot(
   const slot = computeStartSlotAtEpoch(epoch);
   const fork = config.getForkName(slot);
   const aggregatorDomain = config.getDomainAtFork(fork, DOMAIN_AGGREGATE_AND_PROOF);
-  const sszType = ForkSeq[fork] >= ForkSeq.electra ? ssz.electra.AggregateAndProof : ssz.phase0.AggregateAndProof;
+  const sszType = config.getForkTypes(slot).AggregateAndProof;
   return computeSigningRoot(sszType, aggregateAndProof.message, aggregatorDomain);
 }
 

@@ -1,14 +1,16 @@
 import {ContainerType, VectorCompositeType} from "@chainsafe/ssz";
 import {ChainForkConfig} from "@lodestar/config";
 import {DatabaseController, Repository} from "@lodestar/db";
+import {CURRENT_SYNC_COMMITTEE_DEPTH_GLOAS, NEXT_SYNC_COMMITTEE_DEPTH_GLOAS} from "@lodestar/params";
 import {ssz} from "@lodestar/types";
 import {SyncCommitteeWitness} from "../../chain/lightClient/types.js";
 import {Bucket, getBucketNameByValue} from "../buckets.js";
 
-// We add a 1-byte prefix where 0 means pre-electra and 1 means post-electra
+// We add a 1-byte prefix where 0 means pre-Electra, 1 means post-Electra, and 2 means post-Gloas.
 enum PrefixByte {
   PRE_ELECTRA = 0,
   POST_ELECTRA = 1,
+  POST_GLOAS = 2,
 }
 
 export const NUM_WITNESS = 4;
@@ -35,6 +37,35 @@ export class SyncCommitteeWitnessRepository extends Repository<Uint8Array, SyncC
   // Overrides for multi-fork
   encodeValue(value: SyncCommitteeWitness): Uint8Array {
     const numWitness = value.witness.length;
+    const hasGloasBranches =
+      value.currentSyncCommitteeBranch !== undefined || value.nextSyncCommitteeBranch !== undefined;
+
+    if (hasGloasBranches) {
+      if (
+        value.currentSyncCommitteeBranch?.length !== CURRENT_SYNC_COMMITTEE_DEPTH_GLOAS ||
+        value.nextSyncCommitteeBranch?.length !== NEXT_SYNC_COMMITTEE_DEPTH_GLOAS
+      ) {
+        throw Error(
+          `Invalid post-Gloas sync committee branch lengths current=${value.currentSyncCommitteeBranch?.length} next=${value.nextSyncCommitteeBranch?.length}`
+        );
+      }
+
+      const type = new ContainerType({
+        currentSyncCommitteeBranch: new VectorCompositeType(ssz.Root, CURRENT_SYNC_COMMITTEE_DEPTH_GLOAS),
+        nextSyncCommitteeBranch: new VectorCompositeType(ssz.Root, NEXT_SYNC_COMMITTEE_DEPTH_GLOAS),
+        currentSyncCommitteeRoot: ssz.Root,
+        nextSyncCommitteeRoot: ssz.Root,
+      });
+
+      const valueBytes = type.serialize({
+        currentSyncCommitteeBranch: value.currentSyncCommitteeBranch,
+        nextSyncCommitteeBranch: value.nextSyncCommitteeBranch,
+        currentSyncCommitteeRoot: value.currentSyncCommitteeRoot,
+        nextSyncCommitteeRoot: value.nextSyncCommitteeRoot,
+      });
+
+      return prefixData(PrefixByte.POST_GLOAS, valueBytes);
+    }
 
     if (numWitness !== NUM_WITNESS && numWitness !== NUM_WITNESS_ELECTRA) {
       throw Error(`Number of witness can only be 4 pre-electra or 5 post-electra numWitness=${numWitness}`);
@@ -51,19 +82,25 @@ export class SyncCommitteeWitnessRepository extends Repository<Uint8Array, SyncC
     // We need to differentiate between post-electra and pre-electra witness
     // such that we can deserialize correctly
     const isPostElectra = numWitness === NUM_WITNESS_ELECTRA;
-    const prefixByte = new Uint8Array(1);
-    prefixByte[0] = isPostElectra ? PrefixByte.POST_ELECTRA : PrefixByte.PRE_ELECTRA;
-
-    const prefixedData = new Uint8Array(1 + valueBytes.length);
-    prefixedData.set(prefixByte, 0);
-    prefixedData.set(valueBytes, 1);
-
-    return prefixedData;
+    return prefixData(isPostElectra ? PrefixByte.POST_ELECTRA : PrefixByte.PRE_ELECTRA, valueBytes);
   }
 
   decodeValue(data: Uint8Array): SyncCommitteeWitness {
     // First byte is written
     const prefix = data.subarray(0, 1);
+    const isPostGloas = prefix[0] === PrefixByte.POST_GLOAS;
+
+    if (isPostGloas) {
+      const type = new ContainerType({
+        currentSyncCommitteeBranch: new VectorCompositeType(ssz.Root, CURRENT_SYNC_COMMITTEE_DEPTH_GLOAS),
+        nextSyncCommitteeBranch: new VectorCompositeType(ssz.Root, NEXT_SYNC_COMMITTEE_DEPTH_GLOAS),
+        currentSyncCommitteeRoot: ssz.Root,
+        nextSyncCommitteeRoot: ssz.Root,
+      });
+
+      return {witness: [], ...type.deserialize(data.subarray(1))};
+    }
+
     const isPostElectra = prefix[0] === PrefixByte.POST_ELECTRA;
 
     const type = new ContainerType({
@@ -75,3 +112,14 @@ export class SyncCommitteeWitnessRepository extends Repository<Uint8Array, SyncC
     return type.deserialize(data.subarray(1));
   }
 }
+
+function prefixData(prefix: PrefixByte, valueBytes: Uint8Array): Uint8Array {
+  const prefixByte = new Uint8Array(1);
+  prefixByte[0] = prefix;
+
+  const prefixedData = new Uint8Array(1 + valueBytes.length);
+  prefixedData.set(prefixByte, 0);
+  prefixedData.set(valueBytes, 1);
+
+  return prefixedData;
+}