feat: add proxy entry point, resource/prompt forwarding, notifications, and health monitoring

Adds main.ts for config-driven proxy startup, extends router with
resources/list, resources/read, prompts/list, prompts/get forwarding,
notification pass-through from upstreams, and HealthMonitor for
connection state tracking with event-driven state changes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/local-proxy/src/health.ts

@@ -0,0 +1,126 @@
+import { EventEmitter } from 'node:events';
+import type { UpstreamConnection, JsonRpcResponse } from './types.js';
+
+export type HealthState = 'healthy' | 'degraded' | 'disconnected';
+
+export interface HealthStatus {
+  name: string;
+  state: HealthState;
+  lastCheck: number;
+  consecutiveFailures: number;
+}
+
+export interface HealthMonitorOptions {
+  /** Interval between health checks in ms (default: 30000) */
+  intervalMs?: number;
+  /** Number of failures before marking disconnected (default: 3) */
+  failureThreshold?: number;
+}
+
+/**
+ * Monitors upstream connection health with periodic pings.
+ * Emits 'change' events when an upstream's health state changes.
+ */
+export class HealthMonitor extends EventEmitter {
+  private statuses = new Map<string, HealthStatus>();
+  private upstreams = new Map<string, UpstreamConnection>();
+  private timer: ReturnType<typeof setInterval> | null = null;
+  private readonly intervalMs: number;
+  private readonly failureThreshold: number;
+
+  constructor(opts?: HealthMonitorOptions) {
+    super();
+    this.intervalMs = opts?.intervalMs ?? 30000;
+    this.failureThreshold = opts?.failureThreshold ?? 3;
+  }
+
+  track(upstream: UpstreamConnection): void {
+    this.upstreams.set(upstream.name, upstream);
+    this.statuses.set(upstream.name, {
+      name: upstream.name,
+      state: upstream.isAlive() ? 'healthy' : 'disconnected',
+      lastCheck: Date.now(),
+      consecutiveFailures: 0,
+    });
+  }
+
+  untrack(name: string): void {
+    this.upstreams.delete(name);
+    this.statuses.delete(name);
+  }
+
+  start(): void {
+    if (this.timer) return;
+    this.timer = setInterval(() => void this.checkAll(), this.intervalMs);
+  }
+
+  stop(): void {
+    if (this.timer) {
+      clearInterval(this.timer);
+      this.timer = null;
+    }
+  }
+
+  getStatus(name: string): HealthStatus | undefined {
+    return this.statuses.get(name);
+  }
+
+  getAllStatuses(): HealthStatus[] {
+    return [...this.statuses.values()];
+  }
+
+  isHealthy(name: string): boolean {
+    const status = this.statuses.get(name);
+    return status?.state === 'healthy';
+  }
+
+  async checkAll(): Promise<void> {
+    const checks = [...this.upstreams.entries()].map(([name, upstream]) =>
+      this.checkOne(name, upstream),
+    );
+    await Promise.allSettled(checks);
+  }
+
+  private async checkOne(name: string, upstream: UpstreamConnection): Promise<void> {
+    const status = this.statuses.get(name);
+    if (!status) return;
+
+    const oldState = status.state;
+
+    if (!upstream.isAlive()) {
+      status.consecutiveFailures = this.failureThreshold;
+      status.state = 'disconnected';
+      status.lastCheck = Date.now();
+      if (oldState !== 'disconnected') {
+        this.emit('change', { name, oldState, newState: 'disconnected' });
+      }
+      return;
+    }
+
+    try {
+      const response: JsonRpcResponse = await upstream.send({
+        jsonrpc: '2.0',
+        id: `health-${name}-${Date.now()}`,
+        method: 'ping',
+      });
+
+      // A response (even an error for unknown method) means the server is alive
+      if (response) {
+        status.consecutiveFailures = 0;
+        status.state = 'healthy';
+      }
+    } catch {
+      status.consecutiveFailures++;
+      if (status.consecutiveFailures >= this.failureThreshold) {
+        status.state = 'disconnected';
+      } else {
+        status.state = 'degraded';
+      }
+    }
+
+    status.lastCheck = Date.now();
+    if (oldState !== status.state) {
+      this.emit('change', { name, oldState, newState: status.state });
+    }
+  }
+}

src/local-proxy/src/index.ts

@@ -2,6 +2,9 @@
 export { McpRouter } from './router.js';
 export { StdioProxyServer } from './server.js';
 export { StdioUpstream, HttpUpstream } from './upstream/index.js';
+export { HealthMonitor } from './health.js';
+export type { HealthState, HealthStatus, HealthMonitorOptions } from './health.js';
+export { main } from './main.js';
 export type {
   JsonRpcRequest,
   JsonRpcResponse,

src/local-proxy/src/main.ts

@@ -0,0 +1,112 @@
+#!/usr/bin/env node
+import { readFileSync } from 'node:fs';
+import type { ProxyConfig, UpstreamConfig } from './types.js';
+import { McpRouter } from './router.js';
+import { StdioProxyServer } from './server.js';
+import { StdioUpstream } from './upstream/stdio.js';
+import { HttpUpstream } from './upstream/http.js';
+
+function parseArgs(argv: string[]): { configPath: string | undefined; upstreams: string[] } {
+  let configPath: string | undefined;
+  const upstreams: string[] = [];
+  for (let i = 2; i < argv.length; i++) {
+    const arg = argv[i];
+    if (arg === '--config' && i + 1 < argv.length) {
+      configPath = argv[++i];
+    } else if (arg?.startsWith('--config=')) {
+      configPath = arg.slice('--config='.length);
+    } else if (arg === '--upstream' && i + 1 < argv.length) {
+      upstreams.push(argv[++i]!);
+    } else if (arg?.startsWith('--upstream=')) {
+      upstreams.push(arg.slice('--upstream='.length));
+    }
+  }
+  return { configPath, upstreams };
+}
+
+function loadConfig(configPath: string): ProxyConfig {
+  const raw = readFileSync(configPath, 'utf-8');
+  return JSON.parse(raw) as ProxyConfig;
+}
+
+function createUpstream(config: UpstreamConfig) {
+  if (config.transport === 'stdio') {
+    return new StdioUpstream(config);
+  }
+  return new HttpUpstream(config);
+}
+
+export async function main(argv: string[] = process.argv): Promise<{ router: McpRouter; server: StdioProxyServer }> {
+  const args = parseArgs(argv);
+
+  let upstreamConfigs: UpstreamConfig[] = [];
+
+  if (args.configPath) {
+    const config = loadConfig(args.configPath);
+    upstreamConfigs = config.upstreams;
+  }
+
+  // --upstream flags: "name:command arg1 arg2" for STDIO or "name:http://url" for HTTP
+  for (const spec of args.upstreams) {
+    const colonIdx = spec.indexOf(':');
+    if (colonIdx === -1) continue;
+    const name = spec.slice(0, colonIdx);
+    const rest = spec.slice(colonIdx + 1);
+
+    if (rest.startsWith('http://') || rest.startsWith('https://')) {
+      upstreamConfigs.push({
+        serverId: name,
+        name,
+        transport: 'streamable-http',
+        url: rest,
+      });
+    } else {
+      const parts = rest.split(' ').filter(Boolean);
+      const command = parts[0];
+      if (!command) continue;
+      const config: UpstreamConfig = {
+        serverId: name,
+        name,
+        transport: 'stdio',
+        command,
+        args: parts.slice(1),
+      };
+      upstreamConfigs.push(config);
+    }
+  }
+
+  const router = new McpRouter();
+
+  for (const config of upstreamConfigs) {
+    const upstream = createUpstream(config);
+    if (upstream instanceof StdioUpstream) {
+      await upstream.start();
+    }
+    router.addUpstream(upstream);
+  }
+
+  const server = new StdioProxyServer(router);
+
+  const shutdown = async () => {
+    server.stop();
+    await router.closeAll();
+    process.exit(0);
+  };
+
+  process.on('SIGTERM', () => void shutdown());
+  process.on('SIGINT', () => void shutdown());
+
+  server.start();
+  process.stderr.write(`mcpctl-proxy started with ${upstreamConfigs.length} upstream(s)\n`);
+
+  return { router, server };
+}
+
+// Run when executed directly
+const isMain = process.argv[1]?.endsWith('main.js') || process.argv[1]?.endsWith('main.ts');
+if (isMain) {
+  main().catch((err) => {
+    process.stderr.write(`Fatal: ${err}\n`);
+    process.exit(1);
+  });
+}

src/local-proxy/src/router.ts

@@ -1,33 +1,69 @@
-import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse } from './types.js';
+import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse, JsonRpcNotification } from './types.js';
 
 /**
  * Routes MCP requests to the appropriate upstream server.
  *
- * The proxy presents a unified MCP interface to clients. Tools from
- * all upstreams are merged under namespaced prefixes (e.g., "slack/send_message").
+ * The proxy presents a unified MCP interface to clients. Tools, resources,
+ * and prompts from all upstreams are merged under namespaced prefixes
+ * (e.g., "slack/send_message").
  *
- * Routing is done by tool name prefix: "servername/toolname" -> upstream "servername".
+ * Routing is done by name prefix: "servername/toolname" -> upstream "servername".
  */
 export class McpRouter {
   private upstreams = new Map<string, UpstreamConnection>();
   private toolToServer = new Map<string, string>();
+  private resourceToServer = new Map<string, string>();
+  private promptToServer = new Map<string, string>();
+  private notificationHandler: ((notification: JsonRpcNotification) => void) | null = null;
 
   addUpstream(connection: UpstreamConnection): void {
     this.upstreams.set(connection.name, connection);
+    if (this.notificationHandler && connection.onNotification) {
+      const serverName = connection.name;
+      const handler = this.notificationHandler;
+      connection.onNotification((notification) => {
+        handler({
+          ...notification,
+          params: {
+            ...notification.params,
+            _source: serverName,
+          },
+        });
+      });
+    }
   }
 
   removeUpstream(name: string): void {
     this.upstreams.delete(name);
-    // Remove tool mappings for this server
-    for (const [tool, server] of this.toolToServer) {
-      if (server === name) {
-        this.toolToServer.delete(tool);
+    for (const map of [this.toolToServer, this.resourceToServer, this.promptToServer]) {
+      for (const [key, server] of map) {
+        if (server === name) {
+          map.delete(key);
+        }
+      }
+    }
+  }
+
+  setNotificationHandler(handler: (notification: JsonRpcNotification) => void): void {
+    this.notificationHandler = handler;
+    // Wire to all existing upstreams
+    for (const [serverName, upstream] of this.upstreams) {
+      if (upstream.onNotification) {
+        upstream.onNotification((notification) => {
+          handler({
+            ...notification,
+            params: {
+              ...notification.params,
+              _source: serverName,
+            },
+          });
+        });
       }
     }
   }
 
   /**
-   * Initialize tools from all upstreams by calling tools/list on each.
+   * Discover tools from all upstreams by calling tools/list on each.
    */
   async discoverTools(): Promise<Array<{ name: string; description?: string; inputSchema?: unknown }>> {
     const allTools: Array<{ name: string; description?: string; inputSchema?: unknown }> = [];
@@ -36,7 +72,7 @@ export class McpRouter {
       try {
         const response = await upstream.send({
           jsonrpc: '2.0',
-          id: `discover-${serverName}`,
+          id: `discover-tools-${serverName}`,
           method: 'tools/list',
         });
 
@@ -60,25 +96,95 @@ export class McpRouter {
   }
 
   /**
-   * Route a tools/call request to the correct upstream.
+   * Discover resources from all upstreams by calling resources/list on each.
    */
-  async routeToolCall(request: JsonRpcRequest): Promise<JsonRpcResponse> {
-    const params = request.params as { name?: string; arguments?: unknown } | undefined;
-    const toolName = params?.name;
-    if (!toolName) {
+  async discoverResources(): Promise<Array<{ uri: string; name?: string; description?: string; mimeType?: string }>> {
+    const allResources: Array<{ uri: string; name?: string; description?: string; mimeType?: string }> = [];
+
+    for (const [serverName, upstream] of this.upstreams) {
+      try {
+        const response = await upstream.send({
+          jsonrpc: '2.0',
+          id: `discover-resources-${serverName}`,
+          method: 'resources/list',
+        });
+
+        if (response.result && typeof response.result === 'object' && 'resources' in response.result) {
+          const resources = (response.result as { resources: Array<{ uri: string; name?: string; description?: string; mimeType?: string }> }).resources;
+          for (const resource of resources) {
+            const namespacedUri = `${serverName}://${resource.uri}`;
+            this.resourceToServer.set(namespacedUri, serverName);
+            allResources.push({
+              ...resource,
+              uri: namespacedUri,
+            });
+          }
+        }
+      } catch {
+        // Server may be unavailable; skip its resources
+      }
+    }
+
+    return allResources;
+  }
+
+  /**
+   * Discover prompts from all upstreams by calling prompts/list on each.
+   */
+  async discoverPrompts(): Promise<Array<{ name: string; description?: string; arguments?: unknown[] }>> {
+    const allPrompts: Array<{ name: string; description?: string; arguments?: unknown[] }> = [];
+
+    for (const [serverName, upstream] of this.upstreams) {
+      try {
+        const response = await upstream.send({
+          jsonrpc: '2.0',
+          id: `discover-prompts-${serverName}`,
+          method: 'prompts/list',
+        });
+
+        if (response.result && typeof response.result === 'object' && 'prompts' in response.result) {
+          const prompts = (response.result as { prompts: Array<{ name: string; description?: string; arguments?: unknown[] }> }).prompts;
+          for (const prompt of prompts) {
+            const namespacedName = `${serverName}/${prompt.name}`;
+            this.promptToServer.set(namespacedName, serverName);
+            allPrompts.push({
+              ...prompt,
+              name: namespacedName,
+            });
+          }
+        }
+      } catch {
+        // Server may be unavailable; skip its prompts
+      }
+    }
+
+    return allPrompts;
+  }
+
+  /**
+   * Route a namespaced call to the correct upstream, stripping the namespace prefix.
+   */
+  private async routeNamespacedCall(
+    request: JsonRpcRequest,
+    nameField: string,
+    routingMap: Map<string, string>,
+  ): Promise<JsonRpcResponse> {
+    const params = request.params as Record<string, unknown> | undefined;
+    const name = params?.[nameField] as string | undefined;
+    if (!name) {
       return {
         jsonrpc: '2.0',
         id: request.id,
-        error: { code: -32602, message: 'Missing tool name in params' },
+        error: { code: -32602, message: `Missing ${nameField} in params` },
       };
     }
 
-    const serverName = this.toolToServer.get(toolName);
+    const serverName = routingMap.get(name);
     if (!serverName) {
       return {
         jsonrpc: '2.0',
         id: request.id,
-        error: { code: -32601, message: `Unknown tool: ${toolName}` },
+        error: { code: -32601, message: `Unknown ${nameField}: ${name}` },
       };
     }
 
@@ -91,13 +197,16 @@ export class McpRouter {
       };
     }
 
-    // Strip the namespace prefix for the upstream call
-    const originalToolName = toolName.slice(serverName.length + 1);
+    // Strip the namespace prefix
+    const originalName = nameField === 'uri'
+      ? name.slice(`${serverName}://`.length)
+      : name.slice(serverName.length + 1);
+
     const upstreamRequest: JsonRpcRequest = {
       ...request,
       params: {
         ...params,
-        name: originalToolName,
+        [nameField]: originalName,
       },
     };
 
@@ -106,7 +215,7 @@ export class McpRouter {
 
   /**
    * Route a generic request. Handles protocol-level methods locally,
-   * delegates tool calls to upstreams.
+   * delegates tool/resource/prompt calls to upstreams.
    */
   async route(request: JsonRpcRequest): Promise<JsonRpcResponse> {
     switch (request.method) {
@@ -122,6 +231,8 @@ export class McpRouter {
             },
             capabilities: {
               tools: {},
+              resources: {},
+              prompts: {},
             },
           },
         };
@@ -136,7 +247,35 @@ export class McpRouter {
       }
 
       case 'tools/call':
-        return this.routeToolCall(request);
+        return this.routeNamespacedCall(request, 'name', this.toolToServer);
+
+      case 'resources/list': {
+        const resources = await this.discoverResources();
+        return {
+          jsonrpc: '2.0',
+          id: request.id,
+          result: { resources },
+        };
+      }
+
+      case 'resources/read':
+        return this.routeNamespacedCall(request, 'uri', this.resourceToServer);
+
+      case 'resources/subscribe':
+      case 'resources/unsubscribe':
+        return this.routeNamespacedCall(request, 'uri', this.resourceToServer);
+
+      case 'prompts/list': {
+        const prompts = await this.discoverPrompts();
+        return {
+          jsonrpc: '2.0',
+          id: request.id,
+          result: { prompts },
+        };
+      }
+
+      case 'prompts/get':
+        return this.routeNamespacedCall(request, 'name', this.promptToServer);
 
       default:
         return {
@@ -157,5 +296,7 @@ export class McpRouter {
     }
     this.upstreams.clear();
     this.toolToServer.clear();
+    this.resourceToServer.clear();
+    this.promptToServer.clear();
   }
 }

src/local-proxy/src/server.ts

@@ -1,5 +1,5 @@
 import { createInterface } from 'node:readline';
-import type { JsonRpcRequest, JsonRpcResponse, JsonRpcMessage } from './types.js';
+import type { JsonRpcRequest, JsonRpcResponse, JsonRpcNotification, JsonRpcMessage } from './types.js';
 import type { McpRouter } from './router.js';
 
 /**
@@ -16,6 +16,13 @@ export class StdioProxyServer {
   start(): void {
     this.running = true;
 
+    // Forward notifications from upstreams to client
+    this.router.setNotificationHandler((notification) => {
+      if (this.running) {
+        this.sendNotification(notification);
+      }
+    });
+
     const rl = createInterface({ input: process.stdin });
 
     rl.on('line', (line) => {
@@ -54,6 +61,10 @@ export class StdioProxyServer {
     process.stdout.write(JSON.stringify(response) + '\n');
   }
 
+  private sendNotification(notification: JsonRpcNotification): void {
+    process.stdout.write(JSON.stringify(notification) + '\n');
+  }
+
   stop(): void {
     this.running = false;
   }

src/local-proxy/src/types.ts

@@ -69,4 +69,6 @@ export interface UpstreamConnection {
   close(): Promise<void>;
   /** Whether the connection is alive */
   isAlive(): boolean;
+  /** Register a handler for notifications from this upstream */
+  onNotification?(handler: (notification: JsonRpcNotification) => void): void;
 }

src/local-proxy/src/upstream/stdio.ts

@@ -1,6 +1,6 @@
 import { spawn, type ChildProcess } from 'node:child_process';
 import { createInterface } from 'node:readline';
-import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse, UpstreamConfig } from '../types.js';
+import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse, JsonRpcNotification, UpstreamConfig } from '../types.js';
 
 /**
  * Connects to an MCP server over STDIO (spawn a process, write JSON-RPC to stdin, read from stdout).
@@ -13,6 +13,7 @@ export class StdioUpstream implements UpstreamConnection {
     reject: (err: Error) => void;
   }>();
   private alive = false;
+  private notificationHandlers: Array<(notification: JsonRpcNotification) => void> = [];
 
   constructor(private config: UpstreamConfig) {
     this.name = config.name;
@@ -43,12 +44,25 @@ export class StdioUpstream implements UpstreamConnection {
       const rl = createInterface({ input: this.process.stdout });
       rl.on('line', (line) => {
         try {
-          const msg = JSON.parse(line) as JsonRpcResponse;
+          const msg = JSON.parse(line) as Record<string, unknown>;
           if ('id' in msg && msg.id !== undefined) {
-            const pending = this.pendingRequests.get(msg.id);
+            // Response to a pending request
+            const pending = this.pendingRequests.get(msg.id as string | number);
             if (pending) {
-              this.pendingRequests.delete(msg.id);
-              pending.resolve(msg);
+              this.pendingRequests.delete(msg.id as string | number);
+              pending.resolve(msg as unknown as JsonRpcResponse);
+            }
+          } else if ('method' in msg) {
+            // Notification from upstream
+            const notification: JsonRpcNotification = {
+              jsonrpc: '2.0',
+              method: msg.method as string,
+            };
+            if (msg.params) {
+              notification.params = msg.params as Record<string, unknown>;
+            }
+            for (const handler of this.notificationHandlers) {
+              handler(notification);
             }
           }
         } catch {
@@ -97,4 +111,8 @@ export class StdioUpstream implements UpstreamConnection {
   isAlive(): boolean {
     return this.alive;
   }
+
+  onNotification(handler: (notification: JsonRpcNotification) => void): void {
+    this.notificationHandlers.push(handler);
+  }
 }

src/local-proxy/tests/health.test.ts

@@ -0,0 +1,153 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { HealthMonitor } from '../src/health.js';
+import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse } from '../src/types.js';
+
+function mockUpstream(name: string, alive = true): UpstreamConnection {
+  return {
+    name,
+    isAlive: vi.fn(() => alive),
+    close: vi.fn(async () => {}),
+    send: vi.fn(async (req: JsonRpcRequest): Promise<JsonRpcResponse> => ({
+      jsonrpc: '2.0',
+      id: req.id,
+      error: { code: -32601, message: 'Method not found' },
+    })),
+  };
+}
+
+describe('HealthMonitor', () => {
+  let monitor: HealthMonitor;
+
+  beforeEach(() => {
+    monitor = new HealthMonitor({ intervalMs: 100, failureThreshold: 2 });
+  });
+
+  afterEach(() => {
+    monitor.stop();
+  });
+
+  it('tracks upstream and reports initial healthy state', () => {
+    const upstream = mockUpstream('slack');
+    monitor.track(upstream);
+
+    const status = monitor.getStatus('slack');
+    expect(status).toBeDefined();
+    expect(status?.state).toBe('healthy');
+    expect(status?.consecutiveFailures).toBe(0);
+  });
+
+  it('reports disconnected for dead upstream on track', () => {
+    const upstream = mockUpstream('slack', false);
+    monitor.track(upstream);
+
+    expect(monitor.getStatus('slack')?.state).toBe('disconnected');
+  });
+
+  it('marks upstream healthy when ping succeeds', async () => {
+    const upstream = mockUpstream('slack');
+    monitor.track(upstream);
+
+    await monitor.checkAll();
+
+    expect(monitor.isHealthy('slack')).toBe(true);
+    expect(monitor.getStatus('slack')?.consecutiveFailures).toBe(0);
+  });
+
+  it('marks upstream degraded after one failure', async () => {
+    const upstream = mockUpstream('slack');
+    vi.mocked(upstream.send).mockRejectedValue(new Error('timeout'));
+    monitor.track(upstream);
+
+    await monitor.checkAll();
+
+    expect(monitor.getStatus('slack')?.state).toBe('degraded');
+    expect(monitor.getStatus('slack')?.consecutiveFailures).toBe(1);
+  });
+
+  it('marks upstream disconnected after threshold failures', async () => {
+    const upstream = mockUpstream('slack');
+    vi.mocked(upstream.send).mockRejectedValue(new Error('timeout'));
+    monitor.track(upstream);
+
+    await monitor.checkAll();
+    await monitor.checkAll();
+
+    expect(monitor.getStatus('slack')?.state).toBe('disconnected');
+    expect(monitor.getStatus('slack')?.consecutiveFailures).toBe(2);
+  });
+
+  it('recovers from degraded to healthy', async () => {
+    const upstream = mockUpstream('slack');
+    vi.mocked(upstream.send).mockRejectedValueOnce(new Error('timeout'));
+    monitor.track(upstream);
+
+    await monitor.checkAll();
+    expect(monitor.getStatus('slack')?.state).toBe('degraded');
+
+    // Next check succeeds
+    await monitor.checkAll();
+    expect(monitor.getStatus('slack')?.state).toBe('healthy');
+    expect(monitor.getStatus('slack')?.consecutiveFailures).toBe(0);
+  });
+
+  it('emits change events on state transitions', async () => {
+    const upstream = mockUpstream('slack');
+    vi.mocked(upstream.send).mockRejectedValue(new Error('timeout'));
+    monitor.track(upstream);
+
+    const changes: Array<{ name: string; oldState: string; newState: string }> = [];
+    monitor.on('change', (change) => changes.push(change));
+
+    await monitor.checkAll();
+    expect(changes).toHaveLength(1);
+    expect(changes[0]).toEqual({ name: 'slack', oldState: 'healthy', newState: 'degraded' });
+
+    await monitor.checkAll();
+    expect(changes).toHaveLength(2);
+    expect(changes[1]).toEqual({ name: 'slack', oldState: 'degraded', newState: 'disconnected' });
+  });
+
+  it('does not emit when state stays the same', async () => {
+    const upstream = mockUpstream('slack');
+    monitor.track(upstream);
+
+    const changes: unknown[] = [];
+    monitor.on('change', (change) => changes.push(change));
+
+    await monitor.checkAll();
+    await monitor.checkAll();
+
+    expect(changes).toHaveLength(0);
+  });
+
+  it('reports disconnected when upstream is not alive', async () => {
+    const upstream = mockUpstream('slack');
+    monitor.track(upstream);
+
+    vi.mocked(upstream.isAlive).mockReturnValue(false);
+
+    const changes: Array<{ name: string; oldState: string; newState: string }> = [];
+    monitor.on('change', (change) => changes.push(change));
+
+    await monitor.checkAll();
+    expect(monitor.getStatus('slack')?.state).toBe('disconnected');
+    expect(changes).toHaveLength(1);
+  });
+
+  it('returns all statuses', () => {
+    monitor.track(mockUpstream('slack'));
+    monitor.track(mockUpstream('github'));
+
+    const statuses = monitor.getAllStatuses();
+    expect(statuses).toHaveLength(2);
+    expect(statuses.map((s) => s.name)).toEqual(['slack', 'github']);
+  });
+
+  it('untracks upstream', () => {
+    monitor.track(mockUpstream('slack'));
+    monitor.untrack('slack');
+
+    expect(monitor.getStatus('slack')).toBeUndefined();
+    expect(monitor.getAllStatuses()).toHaveLength(0);
+  });
+});

src/local-proxy/tests/router.test.ts

@@ -1,18 +1,43 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { McpRouter } from '../src/router.js';
-import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse } from '../src/types.js';
+import type { UpstreamConnection, JsonRpcRequest, JsonRpcResponse, JsonRpcNotification } from '../src/types.js';
 
-function mockUpstream(name: string, tools: Array<{ name: string; description?: string }> = []): UpstreamConnection {
+function mockUpstream(
+  name: string,
+  opts: {
+    tools?: Array<{ name: string; description?: string }>;
+    resources?: Array<{ uri: string; name?: string; description?: string }>;
+    prompts?: Array<{ name: string; description?: string }>;
+  } = {},
+): UpstreamConnection {
+  const notificationHandlers: Array<(n: JsonRpcNotification) => void> = [];
   return {
     name,
     isAlive: vi.fn(() => true),
     close: vi.fn(async () => {}),
+    onNotification: vi.fn((handler: (n: JsonRpcNotification) => void) => {
+      notificationHandlers.push(handler);
+    }),
     send: vi.fn(async (req: JsonRpcRequest): Promise<JsonRpcResponse> => {
       if (req.method === 'tools/list') {
         return {
           jsonrpc: '2.0',
           id: req.id,
-          result: { tools },
+          result: { tools: opts.tools ?? [] },
+        };
+      }
+      if (req.method === 'resources/list') {
+        return {
+          jsonrpc: '2.0',
+          id: req.id,
+          result: { resources: opts.resources ?? [] },
+        };
+      }
+      if (req.method === 'prompts/list') {
+        return {
+          jsonrpc: '2.0',
+          id: req.id,
+          result: { prompts: opts.prompts ?? [] },
         };
       }
       if (req.method === 'tools/call') {
@@ -24,9 +49,29 @@ function mockUpstream(name: string, tools: Array<{ name: string; description?: s
           },
         };
       }
+      if (req.method === 'resources/read') {
+        return {
+          jsonrpc: '2.0',
+          id: req.id,
+          result: {
+            contents: [{ uri: (req.params as Record<string, unknown>)?.uri, text: 'resource content' }],
+          },
+        };
+      }
+      if (req.method === 'prompts/get') {
+        return {
+          jsonrpc: '2.0',
+          id: req.id,
+          result: {
+            messages: [{ role: 'user', content: { type: 'text', text: 'prompt content' } }],
+          },
+        };
+      }
       return { jsonrpc: '2.0', id: req.id, error: { code: -32601, message: 'Not found' } };
     }),
-  };
+    // expose for tests
+    _notificationHandlers: notificationHandlers,
+  } as UpstreamConnection & { _notificationHandlers: Array<(n: JsonRpcNotification) => void> };
 }
 
 describe('McpRouter', () => {
@@ -37,7 +82,7 @@ describe('McpRouter', () => {
   });
 
   describe('initialize', () => {
-    it('responds with server info and capabilities', async () => {
+    it('responds with server info and capabilities including resources and prompts', async () => {
       const res = await router.route({
         jsonrpc: '2.0',
         id: 1,
@@ -48,6 +93,10 @@ describe('McpRouter', () => {
       const result = res.result as Record<string, unknown>;
       expect(result['protocolVersion']).toBe('2024-11-05');
       expect((result['serverInfo'] as Record<string, unknown>)['name']).toBe('mcpctl-proxy');
+      const capabilities = result['capabilities'] as Record<string, unknown>;
+      expect(capabilities['tools']).toBeDefined();
+      expect(capabilities['resources']).toBeDefined();
+      expect(capabilities['prompts']).toBeDefined();
     });
   });
 
@@ -64,13 +113,17 @@ describe('McpRouter', () => {
     });
 
     it('discovers and namespaces tools from upstreams', async () => {
-      router.addUpstream(mockUpstream('slack', [
-        { name: 'send_message', description: 'Send a message' },
-        { name: 'list_channels', description: 'List channels' },
-      ]));
-      router.addUpstream(mockUpstream('github', [
-        { name: 'create_issue', description: 'Create an issue' },
-      ]));
+      router.addUpstream(mockUpstream('slack', {
+        tools: [
+          { name: 'send_message', description: 'Send a message' },
+          { name: 'list_channels', description: 'List channels' },
+        ],
+      }));
+      router.addUpstream(mockUpstream('github', {
+        tools: [
+          { name: 'create_issue', description: 'Create an issue' },
+        ],
+      }));
 
       const res = await router.route({
         jsonrpc: '2.0',
@@ -90,9 +143,9 @@ describe('McpRouter', () => {
       vi.mocked(failingUpstream.send).mockRejectedValue(new Error('Connection refused'));
       router.addUpstream(failingUpstream);
 
-      router.addUpstream(mockUpstream('working', [
-        { name: 'do_thing', description: 'Does a thing' },
-      ]));
+      router.addUpstream(mockUpstream('working', {
+        tools: [{ name: 'do_thing', description: 'Does a thing' }],
+      }));
 
       const res = await router.route({
         jsonrpc: '2.0',
@@ -108,7 +161,7 @@ describe('McpRouter', () => {
 
   describe('tools/call', () => {
     it('routes call to correct upstream', async () => {
-      const slack = mockUpstream('slack', [{ name: 'send_message' }]);
+      const slack = mockUpstream('slack', { tools: [{ name: 'send_message' }] });
       router.addUpstream(slack);
       await router.discoverTools();
 
@@ -154,7 +207,7 @@ describe('McpRouter', () => {
     });
 
     it('returns error when upstream is dead', async () => {
-      const slack = mockUpstream('slack', [{ name: 'send_message' }]);
+      const slack = mockUpstream('slack', { tools: [{ name: 'send_message' }] });
       router.addUpstream(slack);
       await router.discoverTools();
 
@@ -172,12 +225,177 @@ describe('McpRouter', () => {
     });
   });
 
+  describe('resources/list', () => {
+    it('returns empty resources when no upstreams', async () => {
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'resources/list',
+      });
+
+      const result = res.result as { resources: unknown[] };
+      expect(result.resources).toEqual([]);
+    });
+
+    it('discovers and namespaces resources from upstreams', async () => {
+      router.addUpstream(mockUpstream('files', {
+        resources: [
+          { uri: 'file:///docs/readme.md', name: 'README', description: 'Project readme' },
+        ],
+      }));
+      router.addUpstream(mockUpstream('db', {
+        resources: [
+          { uri: 'db://users', name: 'Users table' },
+        ],
+      }));
+
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'resources/list',
+      });
+
+      const result = res.result as { resources: Array<{ uri: string }> };
+      expect(result.resources).toHaveLength(2);
+      expect(result.resources.map((r) => r.uri)).toContain('files://file:///docs/readme.md');
+      expect(result.resources.map((r) => r.uri)).toContain('db://db://users');
+    });
+  });
+
+  describe('resources/read', () => {
+    it('routes read to correct upstream', async () => {
+      const files = mockUpstream('files', {
+        resources: [{ uri: 'file:///docs/readme.md', name: 'README' }],
+      });
+      router.addUpstream(files);
+      await router.discoverResources();
+
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'resources/read',
+        params: { uri: 'files://file:///docs/readme.md' },
+      });
+
+      expect(res.result).toBeDefined();
+      expect(vi.mocked(files.send)).toHaveBeenCalledWith(
+        expect.objectContaining({
+          method: 'resources/read',
+          params: expect.objectContaining({ uri: 'file:///docs/readme.md' }),
+        }),
+      );
+    });
+
+    it('returns error for unknown resource', async () => {
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'resources/read',
+        params: { uri: 'unknown://resource' },
+      });
+
+      expect(res.error).toBeDefined();
+      expect(res.error?.code).toBe(-32601);
+    });
+  });
+
+  describe('prompts/list', () => {
+    it('returns empty prompts when no upstreams', async () => {
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'prompts/list',
+      });
+
+      const result = res.result as { prompts: unknown[] };
+      expect(result.prompts).toEqual([]);
+    });
+
+    it('discovers and namespaces prompts from upstreams', async () => {
+      router.addUpstream(mockUpstream('code', {
+        prompts: [
+          { name: 'review', description: 'Code review' },
+          { name: 'explain', description: 'Explain code' },
+        ],
+      }));
+
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'prompts/list',
+      });
+
+      const result = res.result as { prompts: Array<{ name: string }> };
+      expect(result.prompts).toHaveLength(2);
+      expect(result.prompts.map((p) => p.name)).toContain('code/review');
+      expect(result.prompts.map((p) => p.name)).toContain('code/explain');
+    });
+  });
+
+  describe('prompts/get', () => {
+    it('routes get to correct upstream', async () => {
+      const code = mockUpstream('code', {
+        prompts: [{ name: 'review', description: 'Code review' }],
+      });
+      router.addUpstream(code);
+      await router.discoverPrompts();
+
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'prompts/get',
+        params: { name: 'code/review' },
+      });
+
+      expect(res.result).toBeDefined();
+      expect(vi.mocked(code.send)).toHaveBeenCalledWith(
+        expect.objectContaining({
+          method: 'prompts/get',
+          params: expect.objectContaining({ name: 'review' }),
+        }),
+      );
+    });
+
+    it('returns error for unknown prompt', async () => {
+      const res = await router.route({
+        jsonrpc: '2.0',
+        id: 1,
+        method: 'prompts/get',
+        params: { name: 'unknown/prompt' },
+      });
+
+      expect(res.error).toBeDefined();
+      expect(res.error?.code).toBe(-32601);
+    });
+  });
+
+  describe('notifications', () => {
+    it('forwards notifications from upstreams with source tag', () => {
+      const received: JsonRpcNotification[] = [];
+      router.setNotificationHandler((n) => received.push(n));
+
+      const slack = mockUpstream('slack', { tools: [{ name: 'send_message' }] }) as UpstreamConnection & {
+        _notificationHandlers: Array<(n: JsonRpcNotification) => void>;
+      };
+      router.addUpstream(slack);
+
+      // Simulate upstream sending a notification
+      for (const handler of slack._notificationHandlers) {
+        handler({ jsonrpc: '2.0', method: 'notifications/progress', params: { progress: 50 } });
+      }
+
+      expect(received).toHaveLength(1);
+      expect(received[0]?.method).toBe('notifications/progress');
+      expect(received[0]?.params?._source).toBe('slack');
+    });
+  });
+
   describe('unknown methods', () => {
     it('returns method not found error', async () => {
       const res = await router.route({
         jsonrpc: '2.0',
         id: 1,
-        method: 'resources/list',
+        method: 'completions/complete',
       });
 
       expect(res.error).toBeDefined();
@@ -192,13 +410,26 @@ describe('McpRouter', () => {
       expect(router.getUpstreamNames()).toEqual(['slack', 'github']);
     });
 
-    it('removes upstream', async () => {
-      const slack = mockUpstream('slack', [{ name: 'send_message' }]);
+    it('removes upstream and cleans up all mappings', async () => {
+      const slack = mockUpstream('slack', {
+        tools: [{ name: 'send_message' }],
+        resources: [{ uri: 'slack://channels' }],
+        prompts: [{ name: 'compose' }],
+      });
       router.addUpstream(slack);
       await router.discoverTools();
+      await router.discoverResources();
+      await router.discoverPrompts();
 
       router.removeUpstream('slack');
       expect(router.getUpstreamNames()).toEqual([]);
+
+      // Verify tool/resource/prompt mappings are cleaned
+      const toolRes = await router.route({
+        jsonrpc: '2.0', id: 1, method: 'tools/call',
+        params: { name: 'slack/send_message' },
+      });
+      expect(toolRes.error?.code).toBe(-32601);
     });
 
     it('closes all upstreams', async () => {