@modelcontextprotocol/sdk
Version:
Model Context Protocol implementation for TypeScript
338 lines • 13.2 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const express_1 = __importDefault(require("express"));
const node_crypto_1 = require("node:crypto");
const zod_1 = require("zod");
const mcp_js_1 = require("../../server/mcp.js");
const streamableHttp_js_1 = require("../../server/streamableHttp.js");
const router_js_1 = require("../../server/auth/router.js");
const bearerAuth_js_1 = require("../../server/auth/middleware/bearerAuth.js");
const types_js_1 = require("../../types.js");
const inMemoryEventStore_js_1 = require("../shared/inMemoryEventStore.js");
const demoInMemoryOAuthProvider_js_1 = require("./demoInMemoryOAuthProvider.js");
// Check for OAuth flag
const useOAuth = process.argv.includes('--oauth');
// Create an MCP server with implementation details
const getServer = () => {
const server = new mcp_js_1.McpServer({
name: 'simple-streamable-http-server',
version: '1.0.0',
}, { capabilities: { logging: {} } });
// Register a simple tool that returns a greeting
server.tool('greet', 'A simple greeting tool', {
name: zod_1.z.string().describe('Name to greet'),
}, async ({ name }) => {
return {
content: [
{
type: 'text',
text: `Hello, ${name}!`,
},
],
};
});
// Register a tool that sends multiple greetings with notifications (with annotations)
server.tool('multi-greet', 'A tool that sends different greetings with delays between them', {
name: zod_1.z.string().describe('Name to greet'),
}, {
title: 'Multiple Greeting Tool',
readOnlyHint: true,
openWorldHint: false
}, async ({ name }, { sendNotification }) => {
const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms));
await sendNotification({
method: "notifications/message",
params: { level: "debug", data: `Starting multi-greet for ${name}` }
});
await sleep(1000); // Wait 1 second before first greeting
await sendNotification({
method: "notifications/message",
params: { level: "info", data: `Sending first greeting to ${name}` }
});
await sleep(1000); // Wait another second before second greeting
await sendNotification({
method: "notifications/message",
params: { level: "info", data: `Sending second greeting to ${name}` }
});
return {
content: [
{
type: 'text',
text: `Good morning, ${name}!`,
}
],
};
});
// Register a simple prompt
server.prompt('greeting-template', 'A simple greeting prompt template', {
name: zod_1.z.string().describe('Name to include in greeting'),
}, async ({ name }) => {
return {
messages: [
{
role: 'user',
content: {
type: 'text',
text: `Please greet ${name} in a friendly manner.`,
},
},
],
};
});
// Register a tool specifically for testing resumability
server.tool('start-notification-stream', 'Starts sending periodic notifications for testing resumability', {
interval: zod_1.z.number().describe('Interval in milliseconds between notifications').default(100),
count: zod_1.z.number().describe('Number of notifications to send (0 for 100)').default(50),
}, async ({ interval, count }, { sendNotification }) => {
const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms));
let counter = 0;
while (count === 0 || counter < count) {
counter++;
try {
await sendNotification({
method: "notifications/message",
params: {
level: "info",
data: `Periodic notification #${counter} at ${new Date().toISOString()}`
}
});
}
catch (error) {
console.error("Error sending notification:", error);
}
// Wait for the specified interval
await sleep(interval);
}
return {
content: [
{
type: 'text',
text: `Started sending periodic notifications every ${interval}ms`,
}
],
};
});
// Create a simple resource at a fixed URI
server.resource('greeting-resource', 'https://example.com/greetings/default', { mimeType: 'text/plain' }, async () => {
return {
contents: [
{
uri: 'https://example.com/greetings/default',
text: 'Hello, world!',
},
],
};
});
return server;
};
const MCP_PORT = 3000;
const AUTH_PORT = 3001;
const app = (0, express_1.default)();
app.use(express_1.default.json());
// Set up OAuth if enabled
let authMiddleware = null;
if (useOAuth) {
// Create auth middleware for MCP endpoints
const mcpServerUrl = new URL(`http://localhost:${MCP_PORT}`);
const authServerUrl = new URL(`http://localhost:${AUTH_PORT}`);
const oauthMetadata = (0, demoInMemoryOAuthProvider_js_1.setupAuthServer)(authServerUrl);
const tokenVerifier = {
verifyAccessToken: async (token) => {
const endpoint = oauthMetadata.introspection_endpoint;
if (!endpoint) {
throw new Error('No token verification endpoint available in metadata');
}
const response = await fetch(endpoint, {
method: 'POST',
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
body: new URLSearchParams({
token: token
}).toString()
});
if (!response.ok) {
throw new Error(`Invalid or expired token: ${await response.text()}`);
}
const data = await response.json();
// Convert the response to AuthInfo format
return {
token,
clientId: data.client_id,
scopes: data.scope ? data.scope.split(' ') : [],
expiresAt: data.exp,
};
}
};
// Add metadata routes to the main MCP server
app.use((0, router_js_1.mcpAuthMetadataRouter)({
oauthMetadata,
resourceServerUrl: mcpServerUrl,
scopesSupported: ['mcp:tools'],
resourceName: 'MCP Demo Server',
}));
authMiddleware = (0, bearerAuth_js_1.requireBearerAuth)({
verifier: tokenVerifier,
requiredScopes: ['mcp:tools'],
resourceMetadataUrl: (0, router_js_1.getOAuthProtectedResourceMetadataUrl)(mcpServerUrl),
});
}
// Map to store transports by session ID
const transports = {};
// MCP POST endpoint with optional auth
const mcpPostHandler = async (req, res) => {
console.log('Received MCP request:', req.body);
if (useOAuth && req.auth) {
console.log('Authenticated user:', req.auth);
}
try {
// Check for existing session ID
const sessionId = req.headers['mcp-session-id'];
let transport;
if (sessionId && transports[sessionId]) {
// Reuse existing transport
transport = transports[sessionId];
}
else if (!sessionId && (0, types_js_1.isInitializeRequest)(req.body)) {
// New initialization request
const eventStore = new inMemoryEventStore_js_1.InMemoryEventStore();
transport = new streamableHttp_js_1.StreamableHTTPServerTransport({
sessionIdGenerator: () => (0, node_crypto_1.randomUUID)(),
eventStore, // Enable resumability
onsessioninitialized: (sessionId) => {
// Store the transport by session ID when session is initialized
// This avoids race conditions where requests might come in before the session is stored
console.log(`Session initialized with ID: ${sessionId}`);
transports[sessionId] = transport;
}
});
// Set up onclose handler to clean up transport when closed
transport.onclose = () => {
const sid = transport.sessionId;
if (sid && transports[sid]) {
console.log(`Transport closed for session ${sid}, removing from transports map`);
delete transports[sid];
}
};
// Connect the transport to the MCP server BEFORE handling the request
// so responses can flow back through the same transport
const server = getServer();
await server.connect(transport);
await transport.handleRequest(req, res, req.body);
return; // Already handled
}
else {
// Invalid request - no session ID or not initialization request
res.status(400).json({
jsonrpc: '2.0',
error: {
code: -32000,
message: 'Bad Request: No valid session ID provided',
},
id: null,
});
return;
}
// Handle the request with existing transport - no need to reconnect
// The existing transport is already connected to the server
await transport.handleRequest(req, res, req.body);
}
catch (error) {
console.error('Error handling MCP request:', error);
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
}
};
// Set up routes with conditional auth middleware
if (useOAuth && authMiddleware) {
app.post('/mcp', authMiddleware, mcpPostHandler);
}
else {
app.post('/mcp', mcpPostHandler);
}
// Handle GET requests for SSE streams (using built-in support from StreamableHTTP)
const mcpGetHandler = async (req, res) => {
const sessionId = req.headers['mcp-session-id'];
if (!sessionId || !transports[sessionId]) {
res.status(400).send('Invalid or missing session ID');
return;
}
if (useOAuth && req.auth) {
console.log('Authenticated SSE connection from user:', req.auth);
}
// Check for Last-Event-ID header for resumability
const lastEventId = req.headers['last-event-id'];
if (lastEventId) {
console.log(`Client reconnecting with Last-Event-ID: ${lastEventId}`);
}
else {
console.log(`Establishing new SSE stream for session ${sessionId}`);
}
const transport = transports[sessionId];
await transport.handleRequest(req, res);
};
// Set up GET route with conditional auth middleware
if (useOAuth && authMiddleware) {
app.get('/mcp', authMiddleware, mcpGetHandler);
}
else {
app.get('/mcp', mcpGetHandler);
}
// Handle DELETE requests for session termination (according to MCP spec)
const mcpDeleteHandler = async (req, res) => {
const sessionId = req.headers['mcp-session-id'];
if (!sessionId || !transports[sessionId]) {
res.status(400).send('Invalid or missing session ID');
return;
}
console.log(`Received session termination request for session ${sessionId}`);
try {
const transport = transports[sessionId];
await transport.handleRequest(req, res);
}
catch (error) {
console.error('Error handling session termination:', error);
if (!res.headersSent) {
res.status(500).send('Error processing session termination');
}
}
};
// Set up DELETE route with conditional auth middleware
if (useOAuth && authMiddleware) {
app.delete('/mcp', authMiddleware, mcpDeleteHandler);
}
else {
app.delete('/mcp', mcpDeleteHandler);
}
app.listen(MCP_PORT, () => {
console.log(`MCP Streamable HTTP Server listening on port ${MCP_PORT}`);
});
// Handle server shutdown
process.on('SIGINT', async () => {
console.log('Shutting down server...');
// Close all active transports to properly clean up resources
for (const sessionId in transports) {
try {
console.log(`Closing transport for session ${sessionId}`);
await transports[sessionId].close();
delete transports[sessionId];
}
catch (error) {
console.error(`Error closing transport for session ${sessionId}:`, error);
}
}
console.log('Server shutdown complete');
process.exit(0);
});
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