ChainSafe · nflaig · Jul 5, 2026 · Jul 5, 2026
@@ -15,6 +15,8 @@ export type {BlockHeaderResponse, BlockId} from "./block.js";
 export {BroadcastValidation} from "./block.js";
 // TODO: Review if re-exporting all these types is necessary
 export type {
+  BuilderResponse,
+  BuilderStatus,
   EpochCommitteeResponse,
   EpochSyncCommitteeResponse,
   FinalityCheckpoints,

@@ -3,6 +3,7 @@ import {ChainForkConfig} from "@lodestar/config";
 import {MAX_VALIDATORS_PER_COMMITTEE} from "@lodestar/params";
 import {
   ArrayOf,
+  BuilderStatus,
   CommitteeIndex,
   Epoch,
   RootHex,
@@ -38,7 +39,7 @@ export type StateArgs = {
 
 export type ValidatorId = string | number;
 
-export type {ValidatorStatus};
+export type {BuilderStatus, ValidatorStatus};
 
 export const RandaoResponseType = new ContainerType({
   randao: ssz.Root,
@@ -57,6 +58,11 @@ export const ValidatorResponseType = new ContainerType({
   status: new StringType<ValidatorStatus>(),
   validator: ssz.phase0.Validator,
 });
+export const BuilderResponseType = new ContainerType({
+  index: ssz.BuilderIndex,
+  status: new StringType<BuilderStatus>(),
+  builder: ssz.gloas.Builder,
+});
 export const ValidatorIdentityType = new ContainerType(
   {
     index: ssz.ValidatorIndex,
@@ -84,18 +90,21 @@ export const EpochSyncCommitteeResponseType = new ContainerType(
   {jsonCase: "eth2"}
 );
 export const ValidatorResponseListType = ArrayOf(ValidatorResponseType);
+export const BuilderResponseListType = ArrayOf(BuilderResponseType);
 export const ValidatorIdentitiesType = ArrayOf(ValidatorIdentityType);
 export const EpochCommitteeResponseListType = ArrayOf(EpochCommitteeResponseType);
 export const ValidatorBalanceListType = ArrayOf(ValidatorBalanceType);
 
 export type RandaoResponse = ValueOf<typeof RandaoResponseType>;
 export type FinalityCheckpoints = ValueOf<typeof FinalityCheckpointsType>;
 export type ValidatorResponse = ValueOf<typeof ValidatorResponseType>;
+export type BuilderResponse = ValueOf<typeof BuilderResponseType>;
 export type EpochCommitteeResponse = ValueOf<typeof EpochCommitteeResponseType>;
 export type ValidatorBalance = ValueOf<typeof ValidatorBalanceType>;
 export type EpochSyncCommitteeResponse = ValueOf<typeof EpochSyncCommitteeResponseType>;
 
 export type ValidatorResponseList = ValueOf<typeof ValidatorResponseListType>;
+export type BuilderResponseList = ValueOf<typeof BuilderResponseListType>;
 export type ValidatorIdentities = ValueOf<typeof ValidatorIdentitiesType>;
 export type EpochCommitteeResponseList = ValueOf<typeof EpochCommitteeResponseListType>;
 export type ValidatorBalanceList = ValueOf<typeof ValidatorBalanceListType>;
@@ -204,6 +213,30 @@ export type Endpoints = {
     ExecutionOptimisticAndFinalizedMeta
   >;
 
+  /**
+   * Get builders from state
+   *
+   * Returns filterable list of builders with their status and index.
+   *
+   * Information will be returned for all indices or public keys that match known builders. If an index or public key does not
+   * match any known builder, no information will be returned but this will not cause an error. There are no guarantees for the
+   * returned data in terms of ordering; both the index and public key are returned for each builder, and can be used to confirm
+   * for which inputs a response has been returned.
+   *
+   * Returns 400 if the requested state is prior to Gloas.
+   */
+  getStateBuilders: Endpoint<
+    "POST",
+    StateArgs & {
+      /** Either hex encoded public key (any bytes48 with 0x prefix) or builder index */
+      builderIds?: ValidatorId[];
+      statuses?: BuilderStatus[];
+    },
+    {params: {state_id: string}; body: {ids?: string[]; statuses?: BuilderStatus[]}},
+    BuilderResponseList,
+    ExecutionOptimisticAndFinalizedMeta
+  >;
+
   /**
    * Get validator identities from state
    *
@@ -489,6 +522,33 @@ export function getDefinitions(_config: ChainForkConfig): RouteDefinitions<Endpo
         meta: ExecutionOptimisticAndFinalizedCodec,
       },
     },
+    getStateBuilders: {
+      url: "/eth/v1/beacon/states/{state_id}/builders",
+      method: "POST",
+      req: JsonOnlyReq({
+        writeReqJson: ({stateId, builderIds, statuses}) => ({
+          params: {state_id: stateId.toString()},
+          body: {
+            ids: toValidatorIdsStr(builderIds),
+            statuses,
+          },
+        }),
+        parseReqJson: ({params, body = {}}) => ({
+          stateId: params.state_id,
+          builderIds: fromValidatorIdsStr(body.ids),
+          statuses: body.statuses ?? undefined,
+        }),
+        schema: {
+          params: {state_id: Schema.StringRequired},
+          body: Schema.Object,
+        },
+      }),
+      resp: {
+        onlySupport: WireFormat.json,
+        data: BuilderResponseListType,
+        meta: ExecutionOptimisticAndFinalizedCodec,
+      },
+    },
     postStateValidatorIdentities: {
       url: "/eth/v1/beacon/states/{state_id}/validator_identities",
       method: "POST",

@@ -205,6 +205,13 @@ export const testData: GenericServerTestCases<Endpoints> = {
     args: {stateId: "head", validatorIds: [pubkeyHex, 1300], statuses: ["active_ongoing"]},
     res: {data: [validatorResponse], meta: {executionOptimistic: true, finalized: false}},
   },
+  getStateBuilders: {
+    args: {stateId: "head", builderIds: [pubkeyHex, 32], statuses: ["active"]},
+    res: {
+      data: [{index: 32, status: "active", builder: ssz.gloas.Builder.defaultValue()}],
+      meta: {executionOptimistic: true, finalized: false},
+    },
+  },
   postStateValidatorIdentities: {
     args: {stateId: "head", validatorIds: [1300]},
     res: {

@@ -9,13 +9,15 @@ import {
   isStatePostAltair,
   isStatePostElectra,
   isStatePostFulu,
+  isStatePostGloas,
 } from "@lodestar/state-transition";
-import {ValidatorIndex, getValidatorStatus, ssz} from "@lodestar/types";
+import {ValidatorIndex, getBuilderStatus, getValidatorStatus, ssz} from "@lodestar/types";
 import {ApiError} from "../../errors.js";
 import {ApiModules} from "../../types.js";
 import {assertUniqueItems} from "../../utils.js";
 import {
   filterStateValidatorsByStatus,
+  getStateBuilderIndex,
   getStateResponseWithRegen,
   getStateValidatorIndex,
   toValidatorResponse,
@@ -143,6 +145,55 @@ export function getBeaconStateApi({
       return this.getStateValidators(args, context);
     },
 
+    async getStateBuilders({stateId, builderIds = [], statuses = []}) {
+      const {state, executionOptimistic, finalized} = await getState(stateId);
+      if (!isStatePostGloas(state)) {
+        throw new ApiError(400, `Builders are not supported for pre-gloas state fork=${state.forkName}`);
+      }
+      const finalizedEpoch = state.finalizedCheckpoint.epoch;
+
+      const builderResponses: routes.beacon.BuilderResponse[] = [];
+      if (builderIds.length) {
+        assertUniqueItems(builderIds, "Duplicate builder IDs provided");
+
+        for (const id of builderIds) {
+          const resp = getStateBuilderIndex(id, state);
+          if (resp.valid) {
+            const builderIndex = resp.builderIndex;
+            const builder = state.getBuilder(builderIndex);
+            const status = getBuilderStatus(builder, finalizedEpoch);
+            if (statuses.length && !statuses.includes(status)) {
+              continue;
+            }
+            builderResponses.push({index: builderIndex, status, builder});
+          }
+        }
+        return {
+          data: builderResponses,
+          meta: {executionOptimistic, finalized},
+        };
+      }
+
+      if (statuses.length) {
+        assertUniqueItems(statuses, "Duplicate statuses provided");
+      }
+
+      const buildersLength = state.getBuildersLength();
+      for (let builderIndex = 0; builderIndex < buildersLength; builderIndex++) {
+        const builder = state.getBuilder(builderIndex);
+        const status = getBuilderStatus(builder, finalizedEpoch);
+        if (statuses.length && !statuses.includes(status)) {
+          continue;
+        }
+        builderResponses.push({index: builderIndex, status, builder});
+      }
+
+      return {
+        data: builderResponses,
+        meta: {executionOptimistic, finalized},
+      };
+    },
+
     async postStateValidatorIdentities({stateId, validatorIds = []}) {
       const {state, executionOptimistic, finalized} = await getState(stateId);
       const {pubkeyCache} = chain;

@@ -1,9 +1,18 @@
 import {routes} from "@lodestar/api";
 import {CheckpointWithHex, IForkChoice} from "@lodestar/fork-choice";
 import {GENESIS_SLOT} from "@lodestar/params";
-import {IBeaconStateView, PubkeyCache} from "@lodestar/state-transition";
-import {BLSPubkey, Epoch, RootHex, Slot, ValidatorIndex, getValidatorStatus, phase0} from "@lodestar/types";
-import {fromHex} from "@lodestar/utils";
+import {IBeaconStateView, IBeaconStateViewGloas, PubkeyCache} from "@lodestar/state-transition";
+import {
+  BLSPubkey,
+  BuilderIndex,
+  Epoch,
+  RootHex,
+  Slot,
+  ValidatorIndex,
+  getValidatorStatus,
+  phase0,
+} from "@lodestar/types";
+import {byteArrayEquals, fromHex} from "@lodestar/utils";
 import {IBeaconChain} from "../../../../chain/index.js";
 import {ApiError, ValidationError} from "../../errors.js";
 
@@ -78,6 +87,50 @@ export function toValidatorResponse(
   };
 }
 
+type StateBuilderIndexResponse =
+  | {valid: true; builderIndex: BuilderIndex}
+  | {valid: false; code: number; reason: string};
+
+export function getStateBuilderIndex(
+  id: routes.beacon.ValidatorId | BLSPubkey,
+  state: IBeaconStateViewGloas
+): StateBuilderIndexResponse {
+  if (typeof id === "string") {
+    // mutate `id` and fallthrough to below
+    if (id.startsWith("0x")) {
+      try {
+        id = fromHex(id);
+      } catch (_e) {
+        return {valid: false, code: 400, reason: "Invalid pubkey hex encoding"};
+      }
+    } else {
+      id = Number(id);
+    }
+  }
+
+  if (typeof id === "number") {
+    const builderIndex = id;
+    // builder is invalid or added later than given stateId
+    if (!Number.isSafeInteger(builderIndex) || builderIndex < 0) {
+      return {valid: false, code: 400, reason: "Invalid builder index"};
+    }
+    if (builderIndex >= state.getBuildersLength()) {
+      return {valid: false, code: 404, reason: "Builder index from future state"};
+    }
+    return {valid: true, builderIndex};
+  }
+
+  // typeof id === Uint8Array
+  // There is no builder pubkey cache, linear scan over the registry
+  const buildersLength = state.getBuildersLength();
+  for (let builderIndex = 0; builderIndex < buildersLength; builderIndex++) {
+    if (byteArrayEquals(state.getBuilder(builderIndex).pubkey, id)) {
+      return {valid: true, builderIndex};
+    }
+  }
+  return {valid: false, code: 404, reason: "Builder pubkey not found in state"};
+}
+
 export function filterStateValidatorsByStatus(
   statuses: string[],
   state: IBeaconStateView,
@@ -122,7 +175,7 @@ export function getStateValidatorIndex(
   if (typeof id === "number") {
     const validatorIndex = id;
     // validator is invalid or added later than given stateId
-    if (!Number.isSafeInteger(validatorIndex)) {
+    if (!Number.isSafeInteger(validatorIndex) || validatorIndex < 0) {
       return {valid: false, code: 400, reason: "Invalid validator index"};
     }
     if (validatorIndex >= state.validatorCount) {

@@ -14,6 +14,9 @@ describe("beacon state api utils", () => {
       expect(getStateValidatorIndex("foo", state, pubkeyCache).valid).toBe(false);
       // "invalid hex"
       expect(getStateValidatorIndex("0xfoo", state, pubkeyCache).valid).toBe(false);
+      // "negative validator index"
+      expect(getStateValidatorIndex("-1", state, pubkeyCache).valid).toBe(false);
+      expect(getStateValidatorIndex(-1, state, pubkeyCache).valid).toBe(false);
     });
 
     it("should return valid: false on validator indices / pubkeys not in the state", () => {

@@ -398,6 +398,14 @@ export class BeaconStateView implements IBeaconStateViewLatestFork {
     return (this.cachedState as CachedBeaconStateGloas).builders.getReadonly(index);
   }
 
+  getBuildersLength(): number {
+    if (this.config.getForkSeq(this.cachedState.slot) < ForkSeq.gloas) {
+      throw new Error("Builders are not supported before Gloas");
+    }
+
+    return (this.cachedState as CachedBeaconStateGloas).builders.length;
+  }
+
   canBuilderCoverBid(builderIndex: BuilderIndex, bidAmount: number): boolean {
     if (this.config.getForkSeq(this.cachedState.slot) < ForkSeq.gloas) {
       throw new Error("Builders are not supported before Gloas");

@@ -255,6 +255,7 @@ export interface IBeaconStateViewGloas extends IBeaconStateViewFulu {
   latestExecutionPayloadBid: ExecutionPayloadBid;
   payloadExpectedWithdrawals: capella.Withdrawal[];
   getBuilder(index: BuilderIndex): gloas.Builder;
+  getBuildersLength(): number;
   canBuilderCoverBid(builderIndex: BuilderIndex, bidAmount: number): boolean;
   getEpochPTCs(epoch: Epoch): Uint32Array[];
   getIndicesInPayloadTimelinessCommittee(validatorIndex: ValidatorIndex, slot: Slot): number[];

@@ -144,6 +144,7 @@ export class NativeBeaconStateView implements IBeaconStateViewLatestFork {
   private _getNextShuffling: EpochShuffling | null = null;
   private _getEffectiveBalanceIncrementsZeroInactive: EffectiveBalanceIncrements | null = null;
   private _getAllValidators: phase0.Validator[] | null = null;
+  private _getBuildersLength: number | null = null;
   private _getAllBalances: number[] | null = null;
   private _getLatestWeakSubjectivityCheckpointEpoch: Epoch | null = null;
   private _getFinalizedRootProof: Uint8Array[] | null = null;
@@ -888,6 +889,13 @@ export class NativeBeaconStateView implements IBeaconStateViewLatestFork {
     return cached;
   }
 
+  getBuildersLength(): number {
+    if (this._getBuildersLength === null) {
+      this._getBuildersLength = this.binding.getBuildersLength();
+    }
+    return this._getBuildersLength;
+  }
+
   canBuilderCoverBid(builderIndex: BuilderIndex, bidAmount: number): boolean {
     return this.binding.canBuilderCoverBid(builderIndex, bidAmount);
   }

@@ -1,5 +1,5 @@
 import {FAR_FUTURE_EPOCH} from "@lodestar/params";
-import {Epoch, phase0} from "../types.js";
+import {Epoch, gloas, phase0} from "../types.js";
 
 /**
  * [Validator status specification](https://hackmd.io/ofFJ5gOmQpu1jjHilHbdQQ)
@@ -53,6 +53,25 @@ export function getValidatorStatus(validator: phase0.Validator, currentEpoch: Ep
   throw new Error("ValidatorStatus unknown");
 }
 
+/**
+ * Statuses as defined in https://github.com/ethereum/beacon-APIs/pull/614
+ */
+export type BuilderStatus = "pending" | "active" | "exited";
+
+/**
+ * Get the status of the builder, `finalizedEpoch` refers to `state.finalized_checkpoint.epoch`
+ */
+export function getBuilderStatus(builder: gloas.Builder, finalizedEpoch: Epoch): BuilderStatus {
+  if (builder.withdrawableEpoch !== FAR_FUTURE_EPOCH) {
+    return "exited";
+  }
+  // Same as is_active_builder check with withdrawable epoch already confirmed to be FAR_FUTURE_EPOCH
+  if (builder.depositEpoch < finalizedEpoch) {
+    return "active";
+  }
+  return "pending";
+}
+
 export function mapToGeneralStatus(subStatus: ValidatorStatus): GeneralValidatorStatus {
   switch (subStatus) {
     case "active_ongoing":