feat: add MCP server testing and tool listing functionality

- Add MCPTestService for testing MCP server connections
- Support stdio, SSE, and HTTP transport types
- Implement workaround for SSE headers bug (SDK Issue #436)
- Create API routes for /api/mcp/test and /api/mcp/tools
- Add API client methods for MCP operations
- Create MCPToolsList component with collapsible schema display
- Add Test button to MCP servers section with status indicators
- Add Headers field for HTTP/SSE servers
- Add Environment Variables field for stdio servers
- Fix text overflow in tools list display

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/server/src/index.ts

@@ -50,6 +50,8 @@ import { createGitHubRoutes } from './routes/github/index.js';
 import { createContextRoutes } from './routes/context/index.js';
 import { createBacklogPlanRoutes } from './routes/backlog-plan/index.js';
 import { cleanupStaleValidations } from './routes/github/routes/validation-common.js';
+import { createMCPRoutes } from './routes/mcp/index.js';
+import { MCPTestService } from './services/mcp-test-service.js';
 
 // Load environment variables
 dotenv.config();
@@ -119,6 +121,7 @@ const agentService = new AgentService(DATA_DIR, events, settingsService);
 const featureLoader = new FeatureLoader();
 const autoModeService = new AutoModeService(events, settingsService);
 const claudeUsageService = new ClaudeUsageService();
+const mcpTestService = new MCPTestService(settingsService);
 
 // Initialize services
 (async () => {
@@ -162,6 +165,7 @@ app.use('/api/claude', createClaudeRoutes(claudeUsageService));
 app.use('/api/github', createGitHubRoutes(events, settingsService));
 app.use('/api/context', createContextRoutes(settingsService));
 app.use('/api/backlog-plan', createBacklogPlanRoutes(events, settingsService));
+app.use('/api/mcp', createMCPRoutes(mcpTestService));
 
 // Create HTTP server
 const server = createServer(app);

apps/server/src/routes/mcp/common.ts

@@ -0,0 +1,20 @@
+/**
+ * Common utilities for MCP routes
+ */
+
+/**
+ * Extract error message from unknown error
+ */
+export function getErrorMessage(error: unknown): string {
+  if (error instanceof Error) {
+    return error.message;
+  }
+  return String(error);
+}
+
+/**
+ * Log error with prefix
+ */
+export function logError(error: unknown, message: string): void {
+  console.error(`[MCP] ${message}:`, error);
+}

apps/server/src/routes/mcp/index.ts

@@ -0,0 +1,36 @@
+/**
+ * MCP routes - HTTP API for testing MCP servers
+ *
+ * Provides endpoints for:
+ * - Testing MCP server connections
+ * - Listing available tools from MCP servers
+ *
+ * Mounted at /api/mcp in the main server.
+ */
+
+import { Router } from 'express';
+import type { MCPTestService } from '../../services/mcp-test-service.js';
+import { createTestServerHandler } from './routes/test-server.js';
+import { createListToolsHandler } from './routes/list-tools.js';
+
+/**
+ * Create MCP router with all endpoints
+ *
+ * Endpoints:
+ * - POST /test - Test MCP server connection
+ * - POST /tools - List tools from MCP server
+ *
+ * @param mcpTestService - Instance of MCPTestService for testing connections
+ * @returns Express Router configured with all MCP endpoints
+ */
+export function createMCPRoutes(mcpTestService: MCPTestService): Router {
+  const router = Router();
+
+  // Test MCP server connection
+  router.post('/test', createTestServerHandler(mcpTestService));
+
+  // List tools from MCP server
+  router.post('/tools', createListToolsHandler(mcpTestService));
+
+  return router;
+}

apps/server/src/routes/mcp/routes/list-tools.ts

@@ -0,0 +1,67 @@
+/**
+ * POST /api/mcp/tools - List tools for an MCP server
+ *
+ * Lists available tools for an MCP server.
+ * Similar to test but focused on tool discovery.
+ *
+ * Request body:
+ *   { serverId: string } - Get tools by server ID from settings
+ *   OR { serverConfig: MCPServerConfig } - Get tools with provided config
+ *
+ * Response: { success: boolean, tools?: MCPToolInfo[], error?: string }
+ */
+
+import type { Request, Response } from 'express';
+import type { MCPTestService } from '../../../services/mcp-test-service.js';
+import type { MCPServerConfig } from '@automaker/types';
+import { getErrorMessage, logError } from '../common.js';
+
+interface ListToolsRequest {
+  serverId?: string;
+  serverConfig?: MCPServerConfig;
+}
+
+/**
+ * Create handler factory for POST /api/mcp/tools
+ */
+export function createListToolsHandler(mcpTestService: MCPTestService) {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const body = req.body as ListToolsRequest;
+
+      if (!body.serverId && !body.serverConfig) {
+        res.status(400).json({
+          success: false,
+          error: 'Either serverId or serverConfig is required',
+        });
+        return;
+      }
+
+      let result;
+      if (body.serverId) {
+        result = await mcpTestService.testServerById(body.serverId);
+      } else if (body.serverConfig) {
+        result = await mcpTestService.testServer(body.serverConfig);
+      } else {
+        res.status(400).json({
+          success: false,
+          error: 'Invalid request',
+        });
+        return;
+      }
+
+      // Return only tool-related information
+      res.json({
+        success: result.success,
+        tools: result.tools,
+        error: result.error,
+      });
+    } catch (error) {
+      logError(error, 'List tools failed');
+      res.status(500).json({
+        success: false,
+        error: getErrorMessage(error),
+      });
+    }
+  };
+}

apps/server/src/routes/mcp/routes/test-server.ts

@@ -0,0 +1,62 @@
+/**
+ * POST /api/mcp/test - Test MCP server connection and list tools
+ *
+ * Tests connection to an MCP server and returns available tools.
+ * Accepts either a serverId to look up config, or a full server config.
+ *
+ * Request body:
+ *   { serverId: string } - Test server by ID from settings
+ *   OR { serverConfig: MCPServerConfig } - Test with provided config
+ *
+ * Response: { success: boolean, tools?: MCPToolInfo[], error?: string, connectionTime?: number }
+ */
+
+import type { Request, Response } from 'express';
+import type { MCPTestService } from '../../../services/mcp-test-service.js';
+import type { MCPServerConfig } from '@automaker/types';
+import { getErrorMessage, logError } from '../common.js';
+
+interface TestServerRequest {
+  serverId?: string;
+  serverConfig?: MCPServerConfig;
+}
+
+/**
+ * Create handler factory for POST /api/mcp/test
+ */
+export function createTestServerHandler(mcpTestService: MCPTestService) {
+  return async (req: Request, res: Response): Promise<void> => {
+    try {
+      const body = req.body as TestServerRequest;
+
+      if (!body.serverId && !body.serverConfig) {
+        res.status(400).json({
+          success: false,
+          error: 'Either serverId or serverConfig is required',
+        });
+        return;
+      }
+
+      let result;
+      if (body.serverId) {
+        result = await mcpTestService.testServerById(body.serverId);
+      } else if (body.serverConfig) {
+        result = await mcpTestService.testServer(body.serverConfig);
+      } else {
+        res.status(400).json({
+          success: false,
+          error: 'Invalid request',
+        });
+        return;
+      }
+
+      res.json(result);
+    } catch (error) {
+      logError(error, 'Test server failed');
+      res.status(500).json({
+        success: false,
+        error: getErrorMessage(error),
+      });
+    }
+  };
+}

apps/server/src/services/mcp-test-service.ts

@@ -0,0 +1,208 @@
+/**
+ * MCP Test Service
+ *
+ * Provides functionality to test MCP server connections and list available tools.
+ * Supports stdio, SSE, and HTTP transport types.
+ */
+
+import { Client } from '@modelcontextprotocol/sdk/client/index.js';
+import { StdioClientTransport } from '@modelcontextprotocol/sdk/client/stdio.js';
+import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js';
+import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';
+import type { MCPServerConfig, MCPToolInfo } from '@automaker/types';
+import type { SettingsService } from './settings-service.js';
+
+const DEFAULT_TIMEOUT = 10000; // 10 seconds
+
+export interface MCPTestResult {
+  success: boolean;
+  tools?: MCPToolInfo[];
+  error?: string;
+  connectionTime?: number;
+  serverInfo?: {
+    name?: string;
+    version?: string;
+  };
+}
+
+/**
+ * MCP Test Service for testing server connections and listing tools
+ */
+export class MCPTestService {
+  private settingsService: SettingsService;
+
+  constructor(settingsService: SettingsService) {
+    this.settingsService = settingsService;
+  }
+
+  /**
+   * Test connection to an MCP server and list its tools
+   */
+  async testServer(serverConfig: MCPServerConfig): Promise<MCPTestResult> {
+    const startTime = Date.now();
+    let client: Client | null = null;
+
+    try {
+      client = new Client({
+        name: 'automaker-mcp-test',
+        version: '1.0.0',
+      });
+
+      // Create transport based on server type
+      const transport = await this.createTransport(serverConfig);
+
+      // Connect with timeout
+      await Promise.race([
+        client.connect(transport),
+        this.timeout(DEFAULT_TIMEOUT, 'Connection timeout'),
+      ]);
+
+      // List tools with timeout
+      const toolsResult = await Promise.race([
+        client.listTools(),
+        this.timeout<{
+          tools: Array<{
+            name: string;
+            description?: string;
+            inputSchema?: Record<string, unknown>;
+          }>;
+        }>(DEFAULT_TIMEOUT, 'List tools timeout'),
+      ]);
+
+      const connectionTime = Date.now() - startTime;
+
+      // Convert tools to MCPToolInfo format
+      const tools: MCPToolInfo[] = (toolsResult.tools || []).map(
+        (tool: { name: string; description?: string; inputSchema?: Record<string, unknown> }) => ({
+          name: tool.name,
+          description: tool.description,
+          inputSchema: tool.inputSchema,
+          enabled: true,
+        })
+      );
+
+      return {
+        success: true,
+        tools,
+        connectionTime,
+        serverInfo: {
+          name: serverConfig.name,
+          version: undefined, // Could be extracted from server info if available
+        },
+      };
+    } catch (error) {
+      const connectionTime = Date.now() - startTime;
+      return {
+        success: false,
+        error: this.getErrorMessage(error),
+        connectionTime,
+      };
+    } finally {
+      // Clean up client connection
+      if (client) {
+        try {
+          await client.close();
+        } catch {
+          // Ignore cleanup errors
+        }
+      }
+    }
+  }
+
+  /**
+   * Test server by ID (looks up config from settings)
+   */
+  async testServerById(serverId: string): Promise<MCPTestResult> {
+    try {
+      const globalSettings = await this.settingsService.getGlobalSettings();
+      const serverConfig = globalSettings.mcpServers?.find((s) => s.id === serverId);
+
+      if (!serverConfig) {
+        return {
+          success: false,
+          error: `Server with ID "${serverId}" not found`,
+        };
+      }
+
+      return this.testServer(serverConfig);
+    } catch (error) {
+      return {
+        success: false,
+        error: this.getErrorMessage(error),
+      };
+    }
+  }
+
+  /**
+   * Create appropriate transport based on server type
+   */
+  private async createTransport(
+    config: MCPServerConfig
+  ): Promise<StdioClientTransport | SSEClientTransport | StreamableHTTPClientTransport> {
+    if (config.type === 'sse') {
+      if (!config.url) {
+        throw new Error('URL is required for SSE transport');
+      }
+      // Use eventSourceInit workaround for SSE headers (SDK bug workaround)
+      // See: https://github.com/modelcontextprotocol/typescript-sdk/issues/436
+      const headers = config.headers;
+      return new SSEClientTransport(new URL(config.url), {
+        requestInit: headers ? { headers } : undefined,
+        eventSourceInit: headers
+          ? {
+              fetch: (url: string | URL | Request, init?: RequestInit) => {
+                const fetchHeaders = new Headers(init?.headers || {});
+                for (const [key, value] of Object.entries(headers)) {
+                  fetchHeaders.set(key, value);
+                }
+                return fetch(url, { ...init, headers: fetchHeaders });
+              },
+            }
+          : undefined,
+      });
+    }
+
+    if (config.type === 'http') {
+      if (!config.url) {
+        throw new Error('URL is required for HTTP transport');
+      }
+      return new StreamableHTTPClientTransport(new URL(config.url), {
+        requestInit: config.headers
+          ? {
+              headers: config.headers,
+            }
+          : undefined,
+      });
+    }
+
+    // Default to stdio
+    if (!config.command) {
+      throw new Error('Command is required for stdio transport');
+    }
+
+    return new StdioClientTransport({
+      command: config.command,
+      args: config.args,
+      env: config.env,
+    });
+  }
+
+  /**
+   * Create a timeout promise
+   */
+  private timeout<T>(ms: number, message: string): Promise<T> {
+    return new Promise((_, reject) => {
+      setTimeout(() => reject(new Error(message)), ms);
+    });
+  }
+
+  /**
+   * Extract error message from unknown error
+   */
+  private getErrorMessage(error: unknown): string {
+    if (error instanceof Error) {
+      return error.message;
+    }
+    return String(error);
+  }
+}