import express from 'express';
import cors from 'cors';
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { HttpServerTransport } from './http-transport.js';
import {
CallToolRequestSchema,
ListToolsRequestSchema,
InitializeRequestSchema,
} from '@modelcontextprotocol/sdk/types.js';
import { toolDefinitions } from './toolDefinitions.js';
import {
registerAgent,
unregisterAgent,
discoverAgents,
sendMessage,
checkForMessages,
updateAgentStatus,
subscribeToNotifications,
unsubscribeFromNotifications,
sendBroadcast,
getPendingNotifications
} from './tools.js';
import { Errors, MCPError } from './errors.js';
const app = express();
const port = process.env.PORT || 3113;
// Middleware
app.use(express.json());
app.use(cors());
// Create MCP server with custom transport
const transport = new HttpServerTransport();
const mcpServer = new Server(
{
name: 'mcp-agentic-framework',
version: '1.0.0',
},
{
capabilities: {
tools: {
listChanged: false
},
},
}
);
// Connect transport
mcpServer.connect(transport);
// Define available tools
mcpServer.setRequestHandler(ListToolsRequestSchema, async () => ({
tools: toolDefinitions,
}));
// Handle tool calls
mcpServer.setRequestHandler(CallToolRequestSchema, async (request) => {
const { name, arguments: args } = request.params;
try {
switch (name) {
case 'register-agent': {
const { name: agentName, description } = args;
return await registerAgent(agentName, description);
}
case 'unregister-agent': {
const { id } = args;
return await unregisterAgent(id);
}
case 'discover-agents': {
return await discoverAgents();
}
case 'send-message': {
const { to, from, message } = args;
return await sendMessage(to, from, message);
}
case 'check-for-messages': {
const { agent_id } = args;
return await checkForMessages(agent_id);
}
case 'update-agent-status': {
const { agent_id, status } = args;
return await updateAgentStatus(agent_id, status);
}
case 'subscribe-to-notifications': {
const { agent_id, events } = args;
return await subscribeToNotifications(agent_id, events);
}
case 'unsubscribe-from-notifications': {
const { agent_id, events } = args;
return await unsubscribeFromNotifications(agent_id, events);
}
case 'send-broadcast': {
const { from, message, priority } = args;
return await sendBroadcast(from, message, priority);
}
case 'get-pending-notifications': {
const { agent_id } = args;
return await getPendingNotifications(agent_id);
}
default:
throw Errors.toolNotFound(name);
}
} catch (error) {
if (error instanceof MCPError) {
throw error;
}
throw Errors.internalError(error.message);
}
});
// Session storage
const sessions = new Map();
// Main MCP endpoint
app.post('/mcp', async (req, res) => {
try {
const message = req.body;
// Log for debugging
console.log('Received message:', JSON.stringify(message, null, 2));
// Process the message through MCP server
const response = await transport.processMessage(message);
// Handle session management for initialize
if (message.method === 'initialize' && response.result) {
const sessionId = `session-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
sessions.set(sessionId, {
createdAt: new Date().toISOString(),
clientInfo: message.params?.clientInfo
});
res.setHeader('Mcp-Session-Id', sessionId);
}
// Check for session ID on non-initialize requests
const sessionId = req.headers['mcp-session-id'];
if (message.method !== 'initialize' && message.id && sessionId && !sessions.has(sessionId)) {
return res.status(404).json({
jsonrpc: '2.0',
id: message.id,
error: {
code: -32001,
message: 'Session not found'
}
});
}
// Send response
if (message.id) {
// It's a request, send the response
res.json(response);
} else {
// It's a notification, send 202 Accepted
res.status(202).send();
}
} catch (error) {
console.error('Error processing message:', error);
res.status(400).json({
jsonrpc: '2.0',
id: req.body.id || null,
error: {
code: error.code || -32603,
message: error.message || 'Internal error',
data: error.data
}
});
}
});
// Health check endpoint
app.get('/health', (req, res) => {
res.json({ status: 'ok', name: 'mcp-agentic-framework', version: '1.0.0' });
});
// Start server
app.listen(port, '127.0.0.1', () => {
console.log(`MCP Agentic Framework HTTP server listening at http://127.0.0.1:${port}/mcp`);
console.log(`Health check available at http://127.0.0.1:${port}/health`);
});
export default app;
