diff --git a/src/lock-ops.mjs b/src/lock-ops.mjs
index e3fbcad..d0ac6b1 100644
--- a/src/lock-ops.mjs
+++ b/src/lock-ops.mjs
@@ -8,7 +8,7 @@ import {
   KIND_APP_DATA,
   MS_PER_SECOND,
 } from './constants.mjs';
-import { nowUnix, relayListLabel } from './utils.mjs';
+import { nowUnix } from './utils.mjs';
 import { defaultHealthManager, buildRelayHealthConfig, RelayHealthManager } from './relay-health-manager.mjs';
 import { publishLock, LockPublisher } from './lock-publisher.mjs';
 import {
@@ -61,20 +61,6 @@ function filterActiveLocks(locks) {
   return locks.filter((lock) => !lock.expiresAt || lock.expiresAt > now);
 }
 
-function withTimeout(promise, timeoutMs, timeoutMessage) {
-  let timeoutHandle;
-  const timeoutPromise = new Promise((_, reject) => {
-    timeoutHandle = setTimeout(() => reject(new Error(timeoutMessage)), timeoutMs);
-  });
-  return Promise.race([promise, timeoutPromise]).finally(() => {
-    if (timeoutHandle) clearTimeout(timeoutHandle);
-  });
-}
-
-function mergeRelayList(primaryRelays, fallbackRelays) {
-  return [...new Set([...primaryRelays, ...fallbackRelays])];
-}
-
 /**
  * Queries relays for active lock events matching the criteria.
  * Uses a tiered approach: tries primary relays first, then falls back to others if needed.
diff --git a/src/lock-publisher.mjs b/src/lock-publisher.mjs
index 61fba13..b330232 100644
--- a/src/lock-publisher.mjs
+++ b/src/lock-publisher.mjs
@@ -6,120 +6,13 @@ import {
   getRelayFallbacks,
   getMinActiveRelayPool,
 } from './torch-config.mjs';
-import { mergeRelayList } from './utils.mjs';
 import { defaultHealthManager, buildRelayHealthConfig } from './relay-health-manager.mjs';
-import { relayListLabel } from './utils.mjs';
-
-function withTimeout(promise, timeoutMs, timeoutMessage) {
-  let timeoutHandle;
-  const timeoutPromise = new Promise((_, reject) => {
-    timeoutHandle = setTimeout(() => reject(new Error(timeoutMessage)), timeoutMs);
-  });
-  return Promise.race([promise, timeoutPromise]).finally(() => {
-    if (timeoutHandle) clearTimeout(timeoutHandle);
-  });
-}
-
-function mergeRelayList(primaryRelays, fallbackRelays) {
-  return [...new Set([...primaryRelays, ...fallbackRelays])];
-}
-
-const PUBLISH_ERROR_CODES = {
-  TIMEOUT: 'publish_timeout',
-  DNS: 'dns_resolution',
-  TCP: 'tcp_connect_timeout',
-  TLS: 'tls_handshake',
-  WEBSOCKET: 'websocket_open_failure',
-  NETWORK: 'network_timeout',
-  CONNECTION_RESET: 'connection_reset',
-  RELAY_UNAVAILABLE: 'relay_unavailable',
-  PERMANENT: 'permanent_validation_error',
-};
-
-const PUBLISH_FAILURE_CATEGORIES = {
-  QUORUM_FAILURE: 'relay_publish_quorum_failure',
-  NON_RETRYABLE: 'relay_publish_non_retryable',
-};
-
-/**
- * Classifies a raw error message into a standardized publication error code.
- * Used to determine if a failure is transient (retryable) or permanent.
- *
- * @param {string|Error} message - The error message or object to classify.
- * @returns {string} One of the PUBLISH_ERROR_CODES constants.
- */
-function classifyPublishError(message) {
-  const normalized = String(message || '').toLowerCase();
-  if (normalized.includes('publish timed out after') || normalized.includes('publish timeout')) {
-    return PUBLISH_ERROR_CODES.TIMEOUT;
-  }
-  if (
-    normalized.includes('enotfound')
-    || normalized.includes('eai_again')
-    || normalized.includes('getaddrinfo')
-    || (normalized.includes('dns') && normalized.includes('websocket'))
-  ) {
-    return PUBLISH_ERROR_CODES.DNS;
-  }
-  if (
-    normalized.includes('connect etimedout')
-    || normalized.includes('tcp connect timed out')
-    || normalized.includes('connect timeout')
-  ) {
-    return PUBLISH_ERROR_CODES.TCP;
-  }
-  if (
-    normalized.includes('tls')
-    || normalized.includes('ssl')
-    || normalized.includes('certificate')
-    || normalized.includes('handshake')
-  ) {
-    return PUBLISH_ERROR_CODES.TLS;
-  }
-  if (
-    normalized.includes('websocket')
-    || normalized.includes('bad response')
-    || normalized.includes('unexpected server response')
-  ) {
-    return PUBLISH_ERROR_CODES.WEBSOCKET;
-  }
-  if (normalized.includes('timed out') || normalized.includes('timeout') || normalized.includes('etimedout')) {
-    return PUBLISH_ERROR_CODES.NETWORK;
-  }
-  if (normalized.includes('econnreset') || normalized.includes('connection reset') || normalized.includes('socket hang up')) {
-    return PUBLISH_ERROR_CODES.CONNECTION_RESET;
-  }
-  if (
-    normalized.includes('unavailable')
-    || normalized.includes('offline')
-    || normalized.includes('econnrefused')
-    || normalized.includes('connection refused')
-    || normalized.includes('enotfound')
-    || normalized.includes('503')
-  ) {
-    return PUBLISH_ERROR_CODES.RELAY_UNAVAILABLE;
-  }
-  return PUBLISH_ERROR_CODES.PERMANENT;
-}
-
-function isTransientPublishCategory(category) {
-  return [
-    PUBLISH_ERROR_CODES.TIMEOUT,
-    PUBLISH_ERROR_CODES.DNS,
-    PUBLISH_ERROR_CODES.TCP,
-    PUBLISH_ERROR_CODES.TLS,
-    PUBLISH_ERROR_CODES.WEBSOCKET,
-    PUBLISH_ERROR_CODES.NETWORK,
-    PUBLISH_ERROR_CODES.CONNECTION_RESET,
-    PUBLISH_ERROR_CODES.RELAY_UNAVAILABLE,
-  ].includes(category);
-}
-
-const MAX_RANDOM = 281474976710655; // 2**48 - 1
-
-export function secureRandom() {
-  return randomInt(0, MAX_RANDOM) / MAX_RANDOM;
-}
+import { relayListLabel, withTimeout, mergeRelayList, secureRandom } from './lock-utils.mjs';
+import {
+  PUBLISH_FAILURE_CATEGORIES,
+  classifyPublishError,
+  isTransientPublishCategory
+} from './lock-error-classifier.mjs';
 
 function calculateBackoffDelayMs(attemptNumber, baseMs, capMs, randomFn = secureRandom) {
   const maxDelay = Math.min(capMs, baseMs * (2 ** Math.max(0, attemptNumber - 1)));
diff --git a/src/lock-utils.mjs b/src/lock-utils.mjs
index dbe1820..974cc06 100644
--- a/src/lock-utils.mjs
+++ b/src/lock-utils.mjs
@@ -3,7 +3,7 @@ import path from 'node:path';
 import { randomInt } from 'node:crypto';
 import { todayDateStr, getIsoWeekStr } from './utils.mjs';
 
-export { relayListLabel } from './utils.mjs';
+export { relayListLabel, mergeRelayList } from './utils.mjs';
 
 /**
  * Scans the local log directory to identify agents that have already completed their task
@@ -51,10 +51,14 @@ export async function getCompletedAgents(cadence, logDir, deps) {
   return completed;
 }
 
-export { withTimeout };
-
-export function mergeRelayList(primaryRelays, fallbackRelays) {
-  return [...new Set([...primaryRelays, ...fallbackRelays])];
+export function withTimeout(promise, timeoutMs, timeoutMessage) {
+  let timeoutHandle;
+  const timeoutPromise = new Promise((_, reject) => {
+    timeoutHandle = setTimeout(() => reject(new Error(timeoutMessage)), timeoutMs);
+  });
+  return Promise.race([promise, timeoutPromise]).finally(() => {
+    if (timeoutHandle) clearTimeout(timeoutHandle);
+  });
 }
 
 const MAX_RANDOM = 281474976710655; // 2**48 - 1
diff --git a/src/relay-health.mjs b/src/relay-health.mjs
index 6e09d0b..3e4f921 100644
--- a/src/relay-health.mjs
+++ b/src/relay-health.mjs
@@ -4,7 +4,7 @@ import WebSocket from 'ws';
 import { finalizeEvent, generateSecretKey, getPublicKey } from 'nostr-tools/pure';
 import { getNamespace, getRelays } from './torch-config.mjs';
 import { MS_PER_SECOND } from './constants.mjs';
-import { withTimeout } from './utils.mjs';
+import { withTimeout } from './lock-utils.mjs';
 
 const PROBE_KIND = 27235;
 
diff --git a/test/utils-async.test.mjs b/test/utils-async.test.mjs
index 66b602e..c5d8749 100644
--- a/test/utils-async.test.mjs
+++ b/test/utils-async.test.mjs
@@ -1,6 +1,6 @@
 import { describe, it } from 'node:test';
 import assert from 'node:assert';
-import { withTimeout } from '../src/utils.mjs';
+import { withTimeout } from '../src/lock-utils.mjs';
 
 describe('Async Utilities', () => {
   describe('withTimeout', () => {
diff --git a/test/utils.test.mjs b/test/utils.test.mjs
index 7051687..40db583 100644
--- a/test/utils.test.mjs
+++ b/test/utils.test.mjs
@@ -2,7 +2,7 @@ import { describe, it, after } from 'node:test';
 import assert from 'node:assert';
 import fs from 'node:fs';
 import path from 'node:path';
-import { getIsoWeekStr, todayDateStr, nowUnix, ensureDir, detectPlatform, relayListLabel } from '../src/utils.mjs';
+import { getIsoWeekStr, todayDateStr, nowUnix, ensureDir, detectPlatform, relayListLabel, mergeRelayList } from '../src/utils.mjs';
 
 describe('Date Utilities', () => {
   describe('todayDateStr', () => {