feat: add ETHEREUM_HTTP_TIMEOUT_MS env var for viem HTTP transport (backport #20919) (#21434)

## Summary
Backport of #20919 to v4-next.

Adds `ETHEREUM_HTTP_TIMEOUT_MS` env var to configure the timeout for
viem HTTP transports used in L1 RPC calls. Introduces
`makeL1HttpTransport` helper to centralize transport creation with
consistent timeout support.

## Conflict Resolution
Cherry-pick had a conflict in `blob-client/src/client/http.ts` because
`next` had refactored `getSlotNumber` to accept `parentBeaconBlockRoot`
as a parameter. Resolved by keeping the v4-next code structure and
applying only the transport change (`makeL1HttpTransport` with timeout
support).

## Commits
1. Cherry-pick with conflict markers (for reviewability)
2. Conflict resolution

ClaudeBox log: https://claudebox.work/s/02b67d20aae96377?run=2

---------

Co-authored-by: Santiago Palladino <santiago@aztec-labs.com>

Author: AztecBot

yarn-project/archiver/src/factory.ts

@@ -1,5 +1,6 @@
 import { EpochCache } from '@aztec/epoch-cache';
 import { createEthereumChain } from '@aztec/ethereum/chain';
+import { makeL1HttpTransport } from '@aztec/ethereum/client';
 import { InboxContract, RollupContract } from '@aztec/ethereum/contracts';
 import type { ViemPublicDebugClient } from '@aztec/ethereum/types';
 import { BlockNumber } from '@aztec/foundation/branded-types';
@@ -18,7 +19,7 @@ import type { L1RollupConstants } from '@aztec/stdlib/epoch-helpers';
 import { getTelemetryClient } from '@aztec/telemetry-client';
 
 import { EventEmitter } from 'events';
-import { createPublicClient, fallback, http } from 'viem';
+import { createPublicClient } from 'viem';
 
 import { Archiver, type ArchiverDeps } from './archiver.js';
 import { type ArchiverConfig, mapArchiverConfig } from './config.js';
@@ -59,17 +60,18 @@ export async function createArchiver(
 
   // Create Ethereum clients
   const chain = createEthereumChain(config.l1RpcUrls, config.l1ChainId);
+  const httpTimeout = config.l1HttpTimeoutMS;
   const publicClient = createPublicClient({
     chain: chain.chainInfo,
-    transport: fallback(config.l1RpcUrls.map(url => http(url, { batch: false }))),
+    transport: makeL1HttpTransport(config.l1RpcUrls, { timeout: httpTimeout }),
     pollingInterval: config.viemPollingIntervalMS,
   });
 
   // Create debug client using debug RPC URLs if available, otherwise fall back to regular RPC URLs
   const debugRpcUrls = config.l1DebugRpcUrls.length > 0 ? config.l1DebugRpcUrls : config.l1RpcUrls;
   const debugClient = createPublicClient({
     chain: chain.chainInfo,
-    transport: fallback(debugRpcUrls.map(url => http(url, { batch: false }))),
+    transport: makeL1HttpTransport(debugRpcUrls, { timeout: httpTimeout }),
     pollingInterval: config.viemPollingIntervalMS,
   }) as ViemPublicDebugClient;
 

yarn-project/aztec-node/src/aztec-node/server.ts

@@ -5,7 +5,7 @@ import { Blob } from '@aztec/blob-lib';
 import { ARCHIVE_HEIGHT, type L1_TO_L2_MSG_TREE_HEIGHT, type NOTE_HASH_TREE_HEIGHT } from '@aztec/constants';
 import { EpochCache, type EpochCacheInterface } from '@aztec/epoch-cache';
 import { createEthereumChain } from '@aztec/ethereum/chain';
-import { getPublicClient } from '@aztec/ethereum/client';
+import { getPublicClient, makeL1HttpTransport } from '@aztec/ethereum/client';
 import { RegistryContract, RollupContract } from '@aztec/ethereum/contracts';
 import type { L1ContractAddresses } from '@aztec/ethereum/l1-contract-addresses';
 import { BlockNumber, CheckpointNumber, EpochNumber, SlotNumber } from '@aztec/foundation/branded-types';
@@ -113,7 +113,7 @@ import {
 } from '@aztec/validator-client';
 import { createWorldStateSynchronizer } from '@aztec/world-state';
 
-import { createPublicClient, fallback, http } from 'viem';
+import { createPublicClient } from 'viem';
 
 import { createSentinel } from '../sentinel/factory.js';
 import { Sentinel } from '../sentinel/sentinel.js';
@@ -257,7 +257,7 @@ export class AztecNodeService implements AztecNode, AztecNodeAdmin, Traceable {
 
     const publicClient = createPublicClient({
       chain: ethereumChain.chainInfo,
-      transport: fallback(config.l1RpcUrls.map((url: string) => http(url, { batch: false }))),
+      transport: makeL1HttpTransport(config.l1RpcUrls, { timeout: config.l1HttpTimeoutMS }),
       pollingInterval: config.viemPollingIntervalMS,
     });
 

yarn-project/blob-client/src/client/config.ts

@@ -3,6 +3,7 @@ import {
   SecretValue,
   booleanConfigHelper,
   getConfigFromMappings,
+  optionalNumberConfigHelper,
 } from '@aztec/foundation/config';
 
 import { type BlobArchiveApiConfig, blobArchiveApiConfigMappings } from '../archive/config.js';
@@ -55,6 +56,9 @@ export interface BlobClientConfig extends BlobArchiveApiConfig {
    * Interval in minutes for uploading healthcheck file to file store (default: 60 = 1 hour)
    */
   blobHealthcheckUploadIntervalMinutes?: number;
+
+  /** Timeout for HTTP requests to the L1 RPC node in ms. */
+  l1HttpTimeoutMS?: number;
 }
 
 export const blobClientConfigMapping: ConfigMappingsType<BlobClientConfig> = {
@@ -108,6 +112,11 @@ export const blobClientConfigMapping: ConfigMappingsType<BlobClientConfig> = {
     description: 'Interval in minutes for uploading healthcheck file to file store (default: 60 = 1 hour)',
     parseEnv: (val: string | undefined) => (val ? +val : undefined),
   },
+  l1HttpTimeoutMS: {
+    env: 'ETHEREUM_HTTP_TIMEOUT_MS',
+    description: 'Timeout for HTTP requests to the L1 RPC node in ms.',
+    ...optionalNumberConfigHelper(),
+  },
   ...blobArchiveApiConfigMappings,
 };
 

yarn-project/blob-client/src/client/http.ts

@@ -1,10 +1,11 @@
 import { Blob, type BlobJson, computeEthVersionedBlobHash } from '@aztec/blob-lib';
+import { makeL1HttpTransport } from '@aztec/ethereum/client';
 import { shuffle } from '@aztec/foundation/array';
 import { type Logger, createLogger } from '@aztec/foundation/log';
 import { makeBackoff, retry } from '@aztec/foundation/retry';
 import { bufferToHex, hexToBuffer } from '@aztec/foundation/string';
 
-import { type RpcBlock, createPublicClient, fallback, http } from 'viem';
+import { type RpcBlock, createPublicClient } from 'viem';
 
 import { createBlobArchiveClient } from '../archive/factory.js';
 import type { BlobArchiveClient } from '../archive/interface.js';
@@ -497,7 +498,7 @@ export class HttpBlobClient implements BlobClientInterface {
     // Ping execution node to get the parentBeaconBlockRoot for this block
     let parentBeaconBlockRoot: string | undefined;
     const client = createPublicClient({
-      transport: fallback(l1RpcUrls.map(url => http(url, { batch: false }))),
+      transport: makeL1HttpTransport(l1RpcUrls, { timeout: this.config.l1HttpTimeoutMS }),
     });
     try {
       const res: RpcBlock = await client.request({

yarn-project/epoch-cache/src/config.ts

@@ -3,7 +3,7 @@ import { type L1ReaderConfig, getL1ReaderConfigFromEnv } from '@aztec/ethereum/l
 
 export type EpochCacheConfig = Pick<
   L1ReaderConfig & L1ContractsConfig,
-  'l1RpcUrls' | 'l1ChainId' | 'viemPollingIntervalMS' | 'ethereumSlotDuration'
+  'l1RpcUrls' | 'l1ChainId' | 'viemPollingIntervalMS' | 'l1HttpTimeoutMS' | 'ethereumSlotDuration'
 >;
 
 export function getEpochCacheConfigEnvVars(): EpochCacheConfig {

yarn-project/epoch-cache/src/epoch_cache.ts

@@ -1,4 +1,5 @@
 import { createEthereumChain } from '@aztec/ethereum/chain';
+import { makeL1HttpTransport } from '@aztec/ethereum/client';
 import { NoCommitteeError, RollupContract } from '@aztec/ethereum/contracts';
 import { EpochNumber, SlotNumber } from '@aztec/foundation/branded-types';
 import { EthAddress } from '@aztec/foundation/eth-address';
@@ -14,7 +15,7 @@ import {
   getTimestampRangeForEpoch,
 } from '@aztec/stdlib/epoch-helpers';
 
-import { createPublicClient, encodeAbiParameters, fallback, http, keccak256 } from 'viem';
+import { createPublicClient, encodeAbiParameters, keccak256 } from 'viem';
 
 import { type EpochCacheConfig, getEpochCacheConfigEnvVars } from './config.js';
 
@@ -93,7 +94,7 @@ export class EpochCache implements EpochCacheInterface {
       const chain = createEthereumChain(config.l1RpcUrls, config.l1ChainId);
       const publicClient = createPublicClient({
         chain: chain.chainInfo,
-        transport: fallback(config.l1RpcUrls.map(url => http(url, { batch: false }))),
+        transport: makeL1HttpTransport(config.l1RpcUrls, { timeout: config.l1HttpTimeoutMS }),
         pollingInterval: config.viemPollingIntervalMS,
       });
       rollup = new RollupContract(publicClient, rollupOrAddress.toString());

yarn-project/ethereum/src/client.ts

@@ -25,18 +25,25 @@ type Config = {
   l1ChainId: number;
   /** The polling interval viem uses in ms */
   viemPollingIntervalMS?: number;
+  /** Timeout for HTTP requests to the L1 RPC node in ms. */
+  l1HttpTimeoutMS?: number;
 };
 
 export type { Config as EthereumClientConfig };
 
+/** Creates a viem fallback HTTP transport for the given L1 RPC URLs. */
+export function makeL1HttpTransport(rpcUrls: string[], opts?: { timeout?: number }) {
+  return fallback(rpcUrls.map(url => http(url, { batch: false, timeout: opts?.timeout })));
+}
+
 // TODO: Use these methods to abstract the creation of viem clients.
 
 /** Returns a viem public client given the L1 config. */
 export function getPublicClient(config: Config): ViemPublicClient {
   const chain = createEthereumChain(config.l1RpcUrls, config.l1ChainId);
   return createPublicClient({
     chain: chain.chainInfo,
-    transport: fallback(config.l1RpcUrls.map(url => http(url, { batch: false }))),
+    transport: makeL1HttpTransport(config.l1RpcUrls, { timeout: config.l1HttpTimeoutMS }),
     pollingInterval: config.viemPollingIntervalMS,
   });
 }
@@ -77,6 +84,7 @@ export function createExtendedL1Client(
   chain: Chain = foundry,
   pollingIntervalMS?: number,
   addressIndex?: number,
+  opts?: { httpTimeoutMS?: number },
 ): ExtendedViemWalletClient {
   const hdAccount =
     typeof mnemonicOrPrivateKeyOrHdAccount === 'string'
@@ -88,7 +96,7 @@ export function createExtendedL1Client(
   const extendedClient = createWalletClient({
     account: hdAccount,
     chain,
-    transport: fallback(rpcUrls.map(url => http(url, { batch: false }))),
+    transport: makeL1HttpTransport(rpcUrls, { timeout: opts?.httpTimeoutMS }),
     pollingInterval: pollingIntervalMS,
   }).extend(publicActions);
 

yarn-project/ethereum/src/l1_reader.ts

@@ -1,4 +1,9 @@
-import { type ConfigMappingsType, getConfigFromMappings, numberConfigHelper } from '@aztec/foundation/config';
+import {
+  type ConfigMappingsType,
+  getConfigFromMappings,
+  numberConfigHelper,
+  optionalNumberConfigHelper,
+} from '@aztec/foundation/config';
 
 import { type L1ContractAddresses, l1ContractAddressesMapping } from './l1_contract_addresses.js';
 
@@ -14,6 +19,8 @@ export interface L1ReaderConfig {
   l1Contracts: L1ContractAddresses;
   /** The polling interval viem uses in ms */
   viemPollingIntervalMS: number;
+  /** Timeout for HTTP requests to the L1 RPC node in ms. */
+  l1HttpTimeoutMS?: number;
 }
 
 export const l1ReaderConfigMappings: ConfigMappingsType<L1ReaderConfig> = {
@@ -43,6 +50,11 @@ export const l1ReaderConfigMappings: ConfigMappingsType<L1ReaderConfig> = {
     description: 'The polling interval viem uses in ms',
     ...numberConfigHelper(1_000),
   },
+  l1HttpTimeoutMS: {
+    env: 'ETHEREUM_HTTP_TIMEOUT_MS',
+    description: 'Timeout for HTTP requests to the L1 RPC node in ms.',
+    ...optionalNumberConfigHelper(),
+  },
 };
 
 export function getL1ReaderConfigFromEnv(): L1ReaderConfig {

yarn-project/foundation/src/config/env_var.ts

@@ -80,6 +80,7 @@ export type EnvVar =
   | 'KEY_STORE_DIRECTORY'
   | 'L1_CHAIN_ID'
   | 'L1_CONSENSUS_HOST_URLS'
+  | 'ETHEREUM_HTTP_TIMEOUT_MS'
   | 'L1_CONSENSUS_HOST_API_KEYS'
   | 'L1_CONSENSUS_HOST_API_KEY_HEADERS'
   | 'LOG_JSON'

yarn-project/prover-node/src/factory.ts

@@ -3,6 +3,7 @@ import type { BlobClientInterface } from '@aztec/blob-client/client';
 import { Blob } from '@aztec/blob-lib';
 import type { EpochCacheInterface } from '@aztec/epoch-cache';
 import { createEthereumChain } from '@aztec/ethereum/chain';
+import { makeL1HttpTransport } from '@aztec/ethereum/client';
 import { RollupContract } from '@aztec/ethereum/contracts';
 import { L1TxUtils } from '@aztec/ethereum/l1-tx-utils';
 import { PublisherManager } from '@aztec/ethereum/publisher-manager';
@@ -27,7 +28,7 @@ import type {
 } from '@aztec/stdlib/interfaces/server';
 import { L1Metrics, type TelemetryClient, getTelemetryClient } from '@aztec/telemetry-client';
 
-import { createPublicClient, fallback, http } from 'viem';
+import { createPublicClient } from 'viem';
 
 import type { SpecificProverNodeConfig } from './config.js';
 import { EpochMonitor } from './monitors/epoch-monitor.js';
@@ -95,7 +96,7 @@ export async function createProverNode(
 
   const publicClient = createPublicClient({
     chain: chain.chainInfo,
-    transport: fallback(config.l1RpcUrls.map((url: string) => http(url, { batch: false }))),
+    transport: makeL1HttpTransport(config.l1RpcUrls, { timeout: config.l1HttpTimeoutMS }),
     pollingInterval: config.viemPollingIntervalMS,
   });