docs(cli): add Vercel provider to setup and doctor

src/cli/doctor.test.ts

@@ -331,6 +331,37 @@ models:
     }
   });
 
+  it('reports WARN when Vercel AI Gateway has no available API key sources', async () => {
+    const originalKey = process.env.AI_GATEWAY_API_KEY;
+    delete process.env.AI_GATEWAY_API_KEY;
+
+    try {
+      mkdirSync(testDir, { recursive: true });
+      const configPath = join(testDir, 'vercel-missing.yaml');
+      writeFileSync(configPath, `
+telegram:
+  bot_token: "test-token"
+  allowed_chat_ids: [123]
+models:
+  default:
+    provider: vercel
+    model: openai/gpt-4.1
+`);
+
+      const ctx: DoctorContext = { configPath, dataDir: testDir };
+      const results = await runChecks(ctx);
+      const modelCheck = results.find(r => r.label.includes('Model connectivity')) as CheckResult | undefined;
+      expect(modelCheck?.status).toBe('warn');
+      expect(modelCheck?.detail).toContain('AI_GATEWAY_API_KEY');
+    } finally {
+      if (originalKey) {
+        process.env.AI_GATEWAY_API_KEY = originalKey;
+      } else {
+        delete process.env.AI_GATEWAY_API_KEY;
+      }
+    }
+  });
+
   it('reports FAIL when Anthropic auth_mode=oauth has no available auth token sources', async () => {
     const originalHome = process.env.HOME;
     const originalToken = process.env.ANTHROPIC_AUTH_TOKEN;

src/cli/doctor.ts

@@ -280,11 +280,12 @@ const checkModelConnectivity: Check = async (ctx) => {
     }
 
     // Providers with API-key style auth (no auth store integration yet)
-    const needsKey = ['gemini', 'openrouter', 'xai', 'github'];
+    const needsKey = ['gemini', 'openrouter', 'vercel', 'xai', 'github'];
     if (needsKey.includes(provider)) {
       const envVarMap: Record<string, string> = {
         gemini: 'GEMINI_API_KEY',
         openrouter: 'OPENROUTER_API_KEY',
+        vercel: 'AI_GATEWAY_API_KEY',
         xai: 'XAI_API_KEY',
         github: 'GITHUB_TOKEN',
       };

src/cli/setup/providers.test.ts

@@ -61,4 +61,18 @@ describe('setupProviders', () => {
     expect(config.models.fast).toBeDefined();
     expect(config.models.fast.provider).toBe('anthropic');
   });
+
+  it('configures vercel gateway as default provider (second tier)', async () => {
+    // Pick "More providers..." then pick "Vercel AI Gateway".
+    // Prompts: api key, endpoint, model, then confirm fast tier.
+    const rl = mockReadline(['4', '3', 'sk-vercel-test123', '', '', 'n']);
+    const p = createPrompter(rl);
+    const builder = new ConfigBuilder();
+    await setupProviders(p, builder);
+    const config = builder.build();
+    expect(config.models.default.provider).toBe('vercel');
+    expect(config.models.default.api_key).toBe('sk-vercel-test123');
+    expect(config.models.default.endpoint).toBe('https://ai-gateway.vercel.sh/v1');
+    expect(config.models.default.model).toBe('openai/gpt-4.1');
+  });
 });

src/cli/setup/providers.ts

@@ -21,6 +21,7 @@ const TOP_TIER: ProviderDef[] = [
 const SECOND_TIER: ProviderDef[] = [
   { name: 'Gemini', provider: 'gemini', defaultModel: 'gemini-2.5-flash', fastModel: 'gemini-2.0-flash-lite', needsApiKey: true, needsEndpoint: false, apiKeyLabel: 'Gemini API key' },
   { name: 'OpenRouter', provider: 'openrouter', defaultModel: 'anthropic/claude-sonnet-4', needsApiKey: true, needsEndpoint: false, apiKeyLabel: 'OpenRouter API key' },
+  { name: 'Vercel AI Gateway', provider: 'vercel', defaultModel: 'openai/gpt-4.1', fastModel: 'openai/gpt-4.1-mini', needsApiKey: true, needsEndpoint: true, defaultEndpoint: 'https://ai-gateway.vercel.sh/v1', apiKeyLabel: 'Vercel AI Gateway API key' },
   { name: 'Z.AI (GLM)', provider: 'zhipuai', defaultModel: 'glm-4.7', needsApiKey: true, needsEndpoint: true, defaultEndpoint: 'https://api.z.ai/api/paas/v4', apiKeyLabel: 'Z.AI API key' },
   { name: 'xAI (Grok)', provider: 'xai', defaultModel: 'grok-3', fastModel: 'grok-3-mini', needsApiKey: true, needsEndpoint: false, apiKeyLabel: 'xAI API key' },
   { name: 'Amazon Bedrock', provider: 'bedrock', defaultModel: 'anthropic.claude-sonnet-4-20250514-v1:0', needsApiKey: false, needsEndpoint: false },
@@ -33,6 +34,7 @@ const PROVIDER_HELP: Record<string, string> = {
   ollama: 'Ollama runs locally — install from https://ollama.com and run: ollama serve',
   gemini: 'Get your API key at https://aistudio.google.com/apikey',
   openrouter: 'Get your API key at https://openrouter.ai/keys (supports 200+ models)',
+  vercel: 'Vercel AI Gateway uses an API key (AI_GATEWAY_API_KEY) and an OpenAI-compatible base URL (default: https://ai-gateway.vercel.sh/v1)',
   zhipuai: 'Get your API key at https://z.ai/manage-apikey/apikey-list (Coding Plan endpoint: https://api.z.ai/api/coding/paas/v4)',
   xai: 'Get your API key at https://console.x.ai',
   bedrock: 'Uses AWS credentials from environment (~/.aws/credentials or IAM role)',