diff --git a/src/auth/anthropic.test.ts b/src/auth/anthropic.test.ts
index c5fc1a2..95df656 100644
--- a/src/auth/anthropic.test.ts
+++ b/src/auth/anthropic.test.ts
@@ -6,6 +6,7 @@ import { join } from 'path';
 describe('auth/anthropic', () => {
   const originalHome = process.env.HOME;
   const originalEnvKey = process.env.ANTHROPIC_API_KEY;
+  const originalEnvToken = process.env.ANTHROPIC_AUTH_TOKEN;
 
   let homeDir: string;
 
@@ -13,6 +14,7 @@ describe('auth/anthropic', () => {
     homeDir = mkdtempSync(join(tmpdir(), 'flynn-auth-anthropic-'));
     process.env.HOME = homeDir;
     delete process.env.ANTHROPIC_API_KEY;
+    delete process.env.ANTHROPIC_AUTH_TOKEN;
     vi.resetModules();
   });
 
@@ -23,6 +25,12 @@ describe('auth/anthropic', () => {
     } else {
       delete process.env.ANTHROPIC_API_KEY;
     }
+
+    if (originalEnvToken) {
+      process.env.ANTHROPIC_AUTH_TOKEN = originalEnvToken;
+    } else {
+      delete process.env.ANTHROPIC_AUTH_TOKEN;
+    }
   });
 
   it('stores, loads, and clears Anthropic API key', async () => {
@@ -41,10 +49,31 @@ describe('auth/anthropic', () => {
     expect(mod.loadStoredAnthropicAuth()).toBeNull();
   });
 
+  it('stores, loads, and clears Anthropic auth token', async () => {
+    const mod = await import('./anthropic.js');
+
+    expect(mod.loadStoredAnthropicAuthToken()).toBeNull();
+
+    mod.storeAnthropicAuthToken('tok-test');
+    expect(mod.loadStoredAnthropicAuthToken()).toBe('tok-test');
+
+    const authFile = join(homeDir, '.config/flynn/auth.json');
+    const mode = statSync(authFile).mode & 0o777;
+    expect(mode).toBe(0o600);
+
+    mod.clearAnthropicAuthToken();
+    expect(mod.loadStoredAnthropicAuthToken()).toBeNull();
+  });
+
   it('getAnthropicApiKey prefers environment variable', async () => {
     process.env.ANTHROPIC_API_KEY = 'sk-env';
     const mod = await import('./anthropic.js');
     expect(mod.getAnthropicApiKey()).toBe('sk-env');
   });
-});
 
+  it('getAnthropicAuthToken prefers environment variable', async () => {
+    process.env.ANTHROPIC_AUTH_TOKEN = 'tok-env';
+    const mod = await import('./anthropic.js');
+    expect(mod.getAnthropicAuthToken()).toBe('tok-env');
+  });
+});
diff --git a/src/auth/anthropic.ts b/src/auth/anthropic.ts
index 464d3b0..851a213 100644
--- a/src/auth/anthropic.ts
+++ b/src/auth/anthropic.ts
@@ -7,7 +7,9 @@ const AUTH_FILE = resolve(AUTH_DIR, 'auth.json');
 
 export interface AnthropicAuthInfo {
   /** Anthropic API key. */
-  api_key: string;
+  api_key?: string;
+  /** Anthropic auth token (OAuth/token mode). */
+  auth_token?: string;
   created_at: string;
 }
 
@@ -51,7 +53,21 @@ export function storeAnthropicAuth(apiKey: string): void {
     throw new Error('Anthropic API key is empty');
   }
   const store = readAuthStore();
-  store.anthropic = { api_key: trimmed, created_at: new Date().toISOString() };
+  store.anthropic = { ...store.anthropic, api_key: trimmed, created_at: new Date().toISOString() };
+  writeAuthStore(store);
+}
+
+export function loadStoredAnthropicAuthToken(): string | null {
+  return loadStoredAnthropicAuth()?.auth_token ?? null;
+}
+
+export function storeAnthropicAuthToken(token: string): void {
+  const trimmed = token.trim();
+  if (!trimmed) {
+    throw new Error('Anthropic auth token is empty');
+  }
+  const store = readAuthStore();
+  store.anthropic = { ...store.anthropic, auth_token: trimmed, created_at: new Date().toISOString() };
   writeAuthStore(store);
 }
 
@@ -61,6 +77,19 @@ export function clearAnthropicAuth(): void {
   writeAuthStore(store);
 }
 
+export function clearAnthropicAuthToken(): void {
+  const store = readAuthStore();
+  if (!store.anthropic) {
+    writeAuthStore(store);
+    return;
+  }
+  delete store.anthropic.auth_token;
+  if (!store.anthropic.api_key && !store.anthropic.auth_token) {
+    delete store.anthropic;
+  }
+  writeAuthStore(store);
+}
+
 /**
  * Get an Anthropic API key from any available source.
  * Priority: ANTHROPIC_API_KEY → stored auth.json.
@@ -70,3 +99,13 @@ export function getAnthropicApiKey(): string | null {
     ?? loadStoredAnthropicAuth()?.api_key
     ?? null;
 }
+
+/**
+ * Get an Anthropic auth token from any available source.
+ * Priority: ANTHROPIC_AUTH_TOKEN → stored auth.json.
+ */
+export function getAnthropicAuthToken(): string | null {
+  return process.env.ANTHROPIC_AUTH_TOKEN
+    ?? loadStoredAnthropicAuth()?.auth_token
+    ?? null;
+}
diff --git a/src/auth/index.ts b/src/auth/index.ts
index b42331c..48e870b 100644
--- a/src/auth/index.ts
+++ b/src/auth/index.ts
@@ -3,6 +3,10 @@ export {
   storeAnthropicAuth,
   clearAnthropicAuth,
   getAnthropicApiKey,
+  loadStoredAnthropicAuthToken,
+  storeAnthropicAuthToken,
+  clearAnthropicAuthToken,
+  getAnthropicAuthToken,
   type AnthropicAuthInfo,
 } from './anthropic.js';