diff --git a/src/index.ts b/src/index.ts
index 4d9265a..2f07a82 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -66,6 +66,7 @@ import { normalizeStoredSeqCursor } from './message-cursor.js';
 import { initCodexTokenRotation } from './codex-token-rotation.js';
 import { initTokenRotation } from './token-rotation.js';
 import {
+  shouldStartTokenRefreshLoop,
   startTokenRefreshLoop,
   stopTokenRefreshLoop,
 } from './token-refresh.js';
@@ -300,8 +301,16 @@ async function main(): Promise<void> {
   initTokenRotation();
   initCodexTokenRotation();
 
-  // Start OAuth token auto-refresh (before subsystems that spawn agents)
-  startTokenRefreshLoop();
+  // Only the Claude service owns Claude OAuth refresh to avoid
+  // cross-service refresh-token races on shared credentials.
+  if (shouldStartTokenRefreshLoop(SERVICE_AGENT_TYPE)) {
+    startTokenRefreshLoop();
+  } else {
+    logger.info(
+      { serviceAgentType: SERVICE_AGENT_TYPE },
+      'Skipping Claude OAuth token auto-refresh for non-Claude service',
+    );
+  }
 
   loadState();
 
diff --git a/src/token-refresh.test.ts b/src/token-refresh.test.ts
new file mode 100644
index 0000000..8a11308
--- /dev/null
+++ b/src/token-refresh.test.ts
@@ -0,0 +1,13 @@
+import { describe, expect, it } from 'vitest';
+
+import { shouldStartTokenRefreshLoop } from './token-refresh.js';
+
+describe('shouldStartTokenRefreshLoop', () => {
+  it('starts refresh for the Claude service', () => {
+    expect(shouldStartTokenRefreshLoop('claude-code')).toBe(true);
+  });
+
+  it('skips refresh for the Codex service', () => {
+    expect(shouldStartTokenRefreshLoop('codex')).toBe(false);
+  });
+});
diff --git a/src/token-refresh.ts b/src/token-refresh.ts
index 6606440..14cf51d 100644
--- a/src/token-refresh.ts
+++ b/src/token-refresh.ts
@@ -19,6 +19,7 @@ import path from 'path';
 import { logger } from './logger.js';
 import { DATA_DIR } from './config.js';
 import { getAllTokens, updateTokenValue } from './token-rotation.js';
+import type { AgentType } from './types.js';
 
 const TOKEN_URL = 'https://api.anthropic.com/v1/oauth/token';
 const CLIENT_ID = '9d1c250a-e61b-44d9-88ed-5944d1962f5e';
@@ -34,6 +35,12 @@ const CHECK_INTERVAL_MS = 5 * 60 * 1000;
 const REFRESH_BEFORE_EXPIRY_MS = 30 * 60 * 1000;
 const REQUEST_TIMEOUT_MS = 15_000;
 
+export function shouldStartTokenRefreshLoop(
+  serviceAgentType: AgentType,
+): boolean {
+  return serviceAgentType === 'claude-code';
+}
+
 interface OAuthCredentials {
   accessToken: string;
   refreshToken: string;