diff --git a/packages/cli/src/zed-integration/zedIntegration.test.ts b/packages/cli/src/zed-integration/zedIntegration.test.ts
index f1cb22bfda..37da3035c3 100644
--- a/packages/cli/src/zed-integration/zedIntegration.test.ts
+++ b/packages/cli/src/zed-integration/zedIntegration.test.ts
@@ -177,6 +177,14 @@ describe('GeminiAgent', () => {
 
     expect(response.protocolVersion).toBe(acp.PROTOCOL_VERSION);
     expect(response.authMethods).toHaveLength(3);
+    const geminiAuth = response.authMethods?.find(
+      (m) => m.id === AuthType.USE_GEMINI,
+    );
+    expect(geminiAuth?._meta).toEqual({
+      'api-key': {
+        provider: 'google',
+      },
+    });
     expect(response.agentCapabilities?.loadSession).toBe(true);
   });
 
@@ -187,6 +195,7 @@ describe('GeminiAgent', () => {
 
     expect(mockConfig.refreshAuth).toHaveBeenCalledWith(
       AuthType.LOGIN_WITH_GOOGLE,
+      undefined,
     );
     expect(mockSettings.setValue).toHaveBeenCalledWith(
       SettingScope.User,
@@ -195,6 +204,25 @@ describe('GeminiAgent', () => {
     );
   });
 
+  it('should authenticate correctly with api-key in _meta', async () => {
+    await agent.authenticate({
+      methodId: AuthType.USE_GEMINI,
+      _meta: {
+        'api-key': 'test-api-key',
+      },
+    } as unknown as acp.AuthenticateRequest);
+
+    expect(mockConfig.refreshAuth).toHaveBeenCalledWith(
+      AuthType.USE_GEMINI,
+      'test-api-key',
+    );
+    expect(mockSettings.setValue).toHaveBeenCalledWith(
+      SettingScope.User,
+      'security.auth.selectedType',
+      AuthType.USE_GEMINI,
+    );
+  });
+
   it('should create a new session', async () => {
     mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
       apiKey: 'test-key',
diff --git a/packages/cli/src/zed-integration/zedIntegration.ts b/packages/cli/src/zed-integration/zedIntegration.ts
index f6c0a63349..d4f1b27b92 100644
--- a/packages/cli/src/zed-integration/zedIntegration.ts
+++ b/packages/cli/src/zed-integration/zedIntegration.ts
@@ -37,12 +37,17 @@ import {
   partListUnionToString,
   LlmRole,
   ApprovalMode,
+  getVersion,
   convertSessionToClientHistory,
 } from '@google/gemini-cli-core';
 import * as acp from '@agentclientprotocol/sdk';
 import { AcpFileSystemService } from './fileSystemService.js';
 import { getAcpErrorMessage } from './acpErrors.js';
 import { Readable, Writable } from 'node:stream';
+
+function hasMeta(obj: unknown): obj is { _meta?: Record<string, unknown> } {
+  return typeof obj === 'object' && obj !== null && '_meta' in obj;
+}
 import type { Content, Part, FunctionCall } from '@google/genai';
 import type { LoadedSettings } from '../config/settings.js';
 import { SettingScope, loadSettings } from '../config/settings.js';
@@ -81,6 +86,7 @@ export async function runZedIntegration(
 export class GeminiAgent {
   private sessions: Map<string, Session> = new Map();
   private clientCapabilities: acp.ClientCapabilities | undefined;
+  private apiKey: string | undefined;
 
   constructor(
     private config: Config,
@@ -97,25 +103,35 @@ export class GeminiAgent {
       {
         id: AuthType.LOGIN_WITH_GOOGLE,
         name: 'Log in with Google',
-        description: null,
+        description: 'Log in with your Google account',
       },
       {
         id: AuthType.USE_GEMINI,
-        name: 'Use Gemini API key',
-        description:
-          'Requires setting the `GEMINI_API_KEY` environment variable',
+        name: 'Gemini API key',
+        description: 'Use an API key with Gemini Developer API',
+        _meta: {
+          'api-key': {
+            provider: 'google',
+          },
+        },
       },
       {
         id: AuthType.USE_VERTEX_AI,
         name: 'Vertex AI',
-        description: null,
+        description: 'Use an API key with Vertex AI GenAI API',
       },
     ];
 
     await this.config.initialize();
+    const version = await getVersion();
     return {
       protocolVersion: acp.PROTOCOL_VERSION,
       authMethods,
+      agentInfo: {
+        name: 'gemini-cli',
+        title: 'Gemini CLI',
+        version,
+      },
       agentCapabilities: {
         loadSession: true,
         promptCapabilities: {
@@ -131,7 +147,8 @@ export class GeminiAgent {
     };
   }
 
-  async authenticate({ methodId }: acp.AuthenticateRequest): Promise<void> {
+  async authenticate(req: acp.AuthenticateRequest): Promise<void> {
+    const { methodId } = req;
     const method = z.nativeEnum(AuthType).parse(methodId);
     const selectedAuthType = this.settings.merged.security.auth.selectedType;
 
@@ -139,17 +156,21 @@ export class GeminiAgent {
     if (selectedAuthType && selectedAuthType !== method) {
       await clearCachedCredentialFile();
     }
+    // Check for api-key in _meta
+    const meta = hasMeta(req) ? req._meta : undefined;
+    const apiKey =
+      typeof meta?.['api-key'] === 'string' ? meta['api-key'] : undefined;
 
     // Refresh auth with the requested method
     // This will reuse existing credentials if they're valid,
     // or perform new authentication if needed
     try {
-      await this.config.refreshAuth(method);
+      if (apiKey) {
+        this.apiKey = apiKey;
+      }
+      await this.config.refreshAuth(method, apiKey ?? this.apiKey);
     } catch (e) {
-      throw new acp.RequestError(
-        getErrorStatus(e) || 401,
-        getAcpErrorMessage(e),
-      );
+      throw new acp.RequestError(-32000, getAcpErrorMessage(e));
     }
     this.settings.setValue(
       SettingScope.User,
@@ -177,7 +198,7 @@ export class GeminiAgent {
     let isAuthenticated = false;
     let authErrorMessage = '';
     try {
-      await config.refreshAuth(authType);
+      await config.refreshAuth(authType, this.apiKey);
       isAuthenticated = true;
 
       // Extra validation for Gemini API key
@@ -199,7 +220,7 @@ export class GeminiAgent {
 
     if (!isAuthenticated) {
       throw new acp.RequestError(
-        401,
+        -32000,
         authErrorMessage || 'Authentication required.',
       );
     }
@@ -302,7 +323,7 @@ export class GeminiAgent {
     // This satisfies the security requirement to verify the user before executing
     // potentially unsafe server definitions.
     try {
-      await config.refreshAuth(selectedAuthType);
+      await config.refreshAuth(selectedAuthType, this.apiKey);
     } catch (e) {
       debugLogger.error(`Authentication failed: ${e}`);
       throw acp.RequestError.authRequired();
diff --git a/packages/core/src/code_assist/oauth2.test.ts b/packages/core/src/code_assist/oauth2.test.ts
index 5726f76451..c1fe162e63 100644
--- a/packages/core/src/code_assist/oauth2.test.ts
+++ b/packages/core/src/code_assist/oauth2.test.ts
@@ -95,6 +95,7 @@ const mockConfig = {
   getNoBrowser: () => false,
   getProxy: () => 'http://test.proxy.com:8080',
   isBrowserLaunchSuppressed: () => false,
+  getExperimentalZedIntegration: () => false,
 } as unknown as Config;
 
 // Mock fetch globally
diff --git a/packages/core/src/code_assist/oauth2.ts b/packages/core/src/code_assist/oauth2.ts
index 14e65f5906..31bc3c0e5e 100644
--- a/packages/core/src/code_assist/oauth2.ts
+++ b/packages/core/src/code_assist/oauth2.ts
@@ -271,9 +271,12 @@ async function initOauthClient(
 
     await triggerPostAuthCallbacks(client.credentials);
   } else {
-    const userConsent = await getConsentForOauth('');
-    if (!userConsent) {
-      throw new FatalCancellationError('Authentication cancelled by user.');
+    // In Zed integration, we skip the interactive consent and directly open the browser
+    if (!config.getExperimentalZedIntegration()) {
+      const userConsent = await getConsentForOauth('');
+      if (!userConsent) {
+        throw new FatalCancellationError('Authentication cancelled by user.');
+      }
     }
 
     const webLogin = await authWithWeb(client);
diff --git a/packages/core/src/config/config.test.ts b/packages/core/src/config/config.test.ts
index a9e9a78415..e92f464fa2 100644
--- a/packages/core/src/config/config.test.ts
+++ b/packages/core/src/config/config.test.ts
@@ -499,6 +499,7 @@ describe('Server Config (config.ts)', () => {
       expect(createContentGeneratorConfig).toHaveBeenCalledWith(
         config,
         authType,
+        undefined,
       );
       // Verify that contentGeneratorConfig is updated
       expect(config.getContentGeneratorConfig()).toEqual(mockContentConfig);
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index dceb65c9a8..7297693b8e 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -1126,7 +1126,7 @@ export class Config {
     return this.contentGenerator;
   }
 
-  async refreshAuth(authMethod: AuthType) {
+  async refreshAuth(authMethod: AuthType, apiKey?: string) {
     // Reset availability service when switching auth
     this.modelAvailabilityService.reset();
 
@@ -1152,6 +1152,7 @@ export class Config {
     const newContentGeneratorConfig = await createContentGeneratorConfig(
       this,
       authMethod,
+      apiKey,
     );
     this.contentGenerator = await createContentGenerator(
       newContentGeneratorConfig,
diff --git a/packages/core/src/core/contentGenerator.ts b/packages/core/src/core/contentGenerator.ts
index 7adae874aa..98d8d50020 100644
--- a/packages/core/src/core/contentGenerator.ts
+++ b/packages/core/src/core/contentGenerator.ts
@@ -90,9 +90,13 @@ export type ContentGeneratorConfig = {
 export async function createContentGeneratorConfig(
   config: Config,
   authType: AuthType | undefined,
+  apiKey?: string,
 ): Promise<ContentGeneratorConfig> {
   const geminiApiKey =
-    process.env['GEMINI_API_KEY'] || (await loadApiKey()) || undefined;
+    apiKey ||
+    process.env['GEMINI_API_KEY'] ||
+    (await loadApiKey()) ||
+    undefined;
   const googleApiKey = process.env['GOOGLE_API_KEY'] || undefined;
   const googleCloudProject =
     process.env['GOOGLE_CLOUD_PROJECT'] ||