diff --git a/integration-tests/acp-integration.test.ts b/integration-tests/acp-integration.test.ts
index 7b989e4c7..61a5a487d 100644
--- a/integration-tests/acp-integration.test.ts
+++ b/integration-tests/acp-integration.test.ts
@@ -146,7 +146,9 @@ function setupAcpTest(
     clearTimeout(waiter.timeout);
     pending.delete(msg.id);
     if (msg.error) {
-      waiter.reject(new Error(msg.error.message ?? 'Unknown error'));
+      const error = new Error(msg.error.message ?? 'Unknown error');
+      (error as Error & { response?: unknown }).response = msg.error;
+      waiter.reject(error);
     } else {
       waiter.resolve(msg.result);
     }
@@ -417,6 +419,42 @@ function setupAcpTest(
     }
   });
 
+  it('includes authMethods in error data when auth is required', async () => {
+    const rig = new TestRig();
+    rig.setup('acp auth methods in error data');
+
+    const { sendRequest, cleanup, stderr } = setupAcpTest(rig);
+
+    try {
+      await sendRequest('initialize', {
+        protocolVersion: 1,
+        clientCapabilities: {
+          fs: { readTextFile: true, writeTextFile: true },
+        },
+      });
+
+      await expect(
+        sendRequest('session/new', {
+          cwd: rig.testDir!,
+          mcpServers: [],
+        }),
+      ).rejects.toMatchObject({
+        response: {
+          data: {
+            authMethods: expect.any(Array),
+          },
+        },
+      });
+    } catch (e) {
+      if (stderr.length) {
+        console.error('Agent stderr:', stderr.join(''));
+      }
+      throw e;
+    } finally {
+      await cleanup();
+    }
+  });
+
   it('receives available_commands_update with slash commands after session creation', async () => {
     const rig = new TestRig();
     rig.setup('acp slash commands');
diff --git a/packages/cli/src/acp-integration/acp.ts b/packages/cli/src/acp-integration/acp.ts
index c3705a98c..68a936c0e 100644
--- a/packages/cli/src/acp-integration/acp.ts
+++ b/packages/cli/src/acp-integration/acp.ts
@@ -9,6 +9,7 @@
 import { z } from 'zod';
 import * as schema from './schema.js';
 import { ACP_ERROR_CODES } from './errorCodes.js';
+import { pickAuthMethodsForDetails } from './authMethods.js';
 export * from './schema.js';
 
 import type { WritableStream, ReadableStream } from 'node:stream/web';
@@ -180,6 +181,7 @@ type ErrorResponse = {
   code: number;
   message: string;
   data?: unknown;
+  authMethods?: schema.AuthMethod[];
 };
 
 type PendingResponse = {
@@ -282,8 +284,11 @@ class Connection {
         details = error.message;
       }
 
-      if (errorName === 'TokenManagerError') {
-        return RequestError.authRequired(details).toResult();
+      if (errorName === 'TokenManagerError' || details?.includes('/auth')) {
+        return RequestError.authRequired(
+          details,
+          pickAuthMethodsForDetails(details),
+        ).toResult();
       }
 
       if (details?.includes('/auth')) {
@@ -339,17 +344,24 @@ class Connection {
 }
 
 export class RequestError extends Error {
-  data?: { details?: string };
+  data?: { details?: string; authMethods?: schema.AuthMethod[] };
 
   constructor(
     public code: number,
     message: string,
     details?: string,
+    authMethods?: schema.AuthMethod[],
   ) {
     super(message);
     this.name = 'RequestError';
-    if (details) {
-      this.data = { details };
+    if (details || authMethods) {
+      this.data = {};
+      if (details) {
+        this.data.details = details;
+      }
+      if (authMethods) {
+        this.data.authMethods = authMethods;
+      }
     }
   }
 
@@ -393,11 +405,15 @@ export class RequestError extends Error {
     );
   }
 
-  static authRequired(details?: string): RequestError {
+  static authRequired(
+    details?: string,
+    authMethods?: schema.AuthMethod[],
+  ): RequestError {
     return new RequestError(
       ACP_ERROR_CODES.AUTH_REQUIRED,
       'Authentication required',
       details,
+      authMethods,
     );
   }
 
diff --git a/packages/cli/src/acp-integration/acpAgent.ts b/packages/cli/src/acp-integration/acpAgent.ts
index ac16921ea..9a2d2555e 100644
--- a/packages/cli/src/acp-integration/acpAgent.ts
+++ b/packages/cli/src/acp-integration/acpAgent.ts
@@ -22,6 +22,7 @@ import {
 } from '@qwen-code/qwen-code-core';
 import type { ApprovalModeValue } from './schema.js';
 import * as acp from './acp.js';
+import { buildAuthMethods } from './authMethods.js';
 import { AcpFileSystemService } from './service/filesystem.js';
 import { Readable, Writable } from 'node:stream';
 import type { LoadedSettings } from '../config/settings.js';
@@ -73,20 +74,7 @@ class GeminiAgent {
     args: acp.InitializeRequest,
   ): Promise<acp.InitializeResponse> {
     this.clientCapabilities = args.clientCapabilities;
-    const authMethods = [
-      {
-        id: AuthType.USE_OPENAI,
-        name: 'Use OpenAI API key',
-        description:
-          'Requires setting the `OPENAI_API_KEY` environment variable',
-      },
-      {
-        id: AuthType.QWEN_OAUTH,
-        name: 'Qwen OAuth',
-        description:
-          'OAuth authentication for Qwen models with 2000 daily requests',
-      },
-    ];
+    const authMethods = buildAuthMethods();
 
     // Get current approval mode from config
     const currentApprovalMode = this.config.getApprovalMode();
@@ -290,7 +278,7 @@ class GeminiAgent {
         `Session not found for id: ${params.sessionId}`,
       );
     }
-    return session.setModel(params);
+    return await session.setModel(params);
   }
 
   private async ensureAuthenticated(config: Config): Promise<void> {
@@ -298,6 +286,7 @@ class GeminiAgent {
     if (!selectedType) {
       throw acp.RequestError.authRequired(
         'Use Qwen Code CLI to authenticate first.',
+        this.pickAuthMethodsForAuthRequired(),
       );
     }
 
@@ -308,10 +297,55 @@ class GeminiAgent {
       console.error(`Authentication failed: ${e}`);
       throw acp.RequestError.authRequired(
         'Authentication failed: ' + (e as Error).message,
+        this.pickAuthMethodsForAuthRequired(selectedType, e),
       );
     }
   }
 
+  private pickAuthMethodsForAuthRequired(
+    selectedType?: AuthType | string,
+    error?: unknown,
+  ): acp.AuthMethod[] {
+    const authMethods = buildAuthMethods();
+    const errorMessage = this.extractErrorMessage(error);
+    if (
+      errorMessage?.includes('qwen-oauth') ||
+      errorMessage?.includes('Qwen OAuth')
+    ) {
+      const qwenOAuthMethods = authMethods.filter(
+        (method) => method.id === AuthType.QWEN_OAUTH,
+      );
+      return qwenOAuthMethods.length ? qwenOAuthMethods : authMethods;
+    }
+
+    if (selectedType) {
+      const matchedMethods = authMethods.filter(
+        (method) => method.id === selectedType,
+      );
+      return matchedMethods.length ? matchedMethods : authMethods;
+    }
+
+    return authMethods;
+  }
+
+  private extractErrorMessage(error?: unknown): string | undefined {
+    if (error instanceof Error) {
+      return error.message;
+    }
+    if (
+      typeof error === 'object' &&
+      error != null &&
+      'message' in error &&
+      typeof error.message === 'string'
+    ) {
+      return error.message;
+    }
+    if (typeof error === 'string') {
+      return error;
+    }
+    return undefined;
+  }
+
   private setupFileSystem(config: Config): void {
     if (!this.clientCapabilities?.fs) {
       return;
diff --git a/packages/cli/src/acp-integration/authMethods.ts b/packages/cli/src/acp-integration/authMethods.ts
new file mode 100644
index 000000000..35cafdc71
--- /dev/null
+++ b/packages/cli/src/acp-integration/authMethods.ts
@@ -0,0 +1,47 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { AuthType } from '@qwen-code/qwen-code-core';
+import type { AuthMethod } from './schema.js';
+
+export function buildAuthMethods(): AuthMethod[] {
+  return [
+    {
+      id: AuthType.USE_OPENAI,
+      name: 'Use OpenAI API key',
+      description: 'Requires setting the `OPENAI_API_KEY` environment variable',
+      type: 'terminal',
+      args: ['--auth-type=openai'],
+    },
+    {
+      id: AuthType.QWEN_OAUTH,
+      name: 'Qwen OAuth',
+      description:
+        'OAuth authentication for Qwen models with free daily requests',
+      type: 'terminal',
+      args: ['--auth-type=qwen-oauth'],
+    },
+  ];
+}
+
+export function filterAuthMethodsById(
+  authMethods: AuthMethod[],
+  authMethodId: string,
+): AuthMethod[] {
+  return authMethods.filter((method) => method.id === authMethodId);
+}
+
+export function pickAuthMethodsForDetails(details?: string): AuthMethod[] {
+  const authMethods = buildAuthMethods();
+  if (!details) {
+    return authMethods;
+  }
+  if (details.includes('qwen-oauth') || details.includes('Qwen OAuth')) {
+    const narrowed = filterAuthMethodsById(authMethods, AuthType.QWEN_OAUTH);
+    return narrowed.length ? narrowed : authMethods;
+  }
+  return authMethods;
+}
diff --git a/packages/cli/src/acp-integration/schema.ts b/packages/cli/src/acp-integration/schema.ts
index 8e81b140d..cf616e56f 100644
--- a/packages/cli/src/acp-integration/schema.ts
+++ b/packages/cli/src/acp-integration/schema.ts
@@ -406,9 +406,12 @@ export const agentCapabilitiesSchema = z.object({
 });
 
 export const authMethodSchema = z.object({
+  args: z.array(z.string()).optional(),
   description: z.string().nullable(),
+  env: z.record(z.string()).optional(),
   id: z.string(),
   name: z.string(),
+  type: z.string().optional(),
 });
 
 export const clientResponseSchema = z.union([
diff --git a/packages/core/src/qwen/qwenOAuth2.test.ts b/packages/core/src/qwen/qwenOAuth2.test.ts
index 920ca85e3..0d51f047e 100644
--- a/packages/core/src/qwen/qwenOAuth2.test.ts
+++ b/packages/core/src/qwen/qwenOAuth2.test.ts
@@ -840,7 +840,9 @@ describe('getQwenOAuthClient', () => {
           requireCachedCredentials: true,
         }),
       ),
-    ).rejects.toThrow('Please use /auth to re-authenticate.');
+    ).rejects.toThrow(
+      'Qwen OAuth credentials expired. Please use /auth to re-authenticate with qwen-oauth.',
+    );
 
     expect(global.fetch).not.toHaveBeenCalled();
 
diff --git a/packages/core/src/qwen/qwenOAuth2.ts b/packages/core/src/qwen/qwenOAuth2.ts
index b18c0319d..940bdcb18 100644
--- a/packages/core/src/qwen/qwenOAuth2.ts
+++ b/packages/core/src/qwen/qwenOAuth2.ts
@@ -516,7 +516,9 @@ export async function getQwenOAuthClient(
     }
 
     if (options?.requireCachedCredentials) {
-      throw new Error('Please use /auth to re-authenticate.');
+      throw new Error(
+        'Qwen OAuth credentials expired. Please use /auth to re-authenticate with qwen-oauth.',
+      );
     }
 
     // If we couldn't obtain valid credentials via SharedTokenManager, fall back to