9a771fb157* refactor: a transport trait and streamable http client * test: test with js streamable http server * refactor: separate sse stream connection * fix(test): streamable http client test with js * fix(test): wait longer time for js server startup
105 lines
No EOL
2.8 KiB
JavaScript
105 lines
No EOL
2.8 KiB
JavaScript
import { McpServer, ResourceTemplate } from "@modelcontextprotocol/sdk/server/mcp.js";
|
|
import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
|
|
import { isInitializeRequest } from "@modelcontextprotocol/sdk/types.js"
|
|
import { randomUUID } from "node:crypto"
|
|
import { z } from "zod";
|
|
import express from "express"
|
|
|
|
const app = express();
|
|
app.use(express.json());
|
|
|
|
// Map to store transports by session ID
|
|
const transports = {};
|
|
|
|
// Handle POST requests for client-to-server communication
|
|
app.post('/mcp', async (req, res) => {
|
|
// 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 && isInitializeRequest(req.body)) {
|
|
// New initialization request
|
|
transport = new StreamableHTTPServerTransport({
|
|
sessionIdGenerator: () => randomUUID().toString(),
|
|
onsessioninitialized: (sessionId) => {
|
|
// Store the transport by session ID
|
|
transports[sessionId] = transport;
|
|
}
|
|
});
|
|
|
|
// Clean up transport when closed
|
|
transport.onclose = () => {
|
|
if (transport.sessionId) {
|
|
delete transports[transport.sessionId];
|
|
}
|
|
};
|
|
const server = new McpServer({
|
|
name: "example-server",
|
|
version: "1.0.0"
|
|
});
|
|
|
|
server.resource(
|
|
"greeting",
|
|
new ResourceTemplate("greeting://{name}", { list: undefined }),
|
|
async (uri, { name }) => ({
|
|
contents: [{
|
|
uri: uri.href,
|
|
text: `Hello, ${name}`
|
|
}]
|
|
})
|
|
);
|
|
|
|
server.tool(
|
|
"add",
|
|
{ a: z.number(), b: z.number() },
|
|
async ({ a, b }) => ({
|
|
"content": [
|
|
{
|
|
"type": "text",
|
|
"text": `${a + b}`
|
|
}
|
|
]
|
|
})
|
|
);
|
|
|
|
// Connect to the MCP server
|
|
await server.connect(transport);
|
|
} else {
|
|
// Invalid 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
|
|
await transport.handleRequest(req, res, req.body);
|
|
});
|
|
|
|
// Reusable handler for GET and DELETE requests
|
|
const handleSessionRequest = async (req, res) => {
|
|
const sessionId = req.headers['mcp-session-id'];
|
|
if (!sessionId || !transports[sessionId]) {
|
|
res.status(400).send('Invalid or missing session ID');
|
|
return;
|
|
}
|
|
|
|
const transport = transports[sessionId];
|
|
await transport.handleRequest(req, res);
|
|
};
|
|
|
|
// Handle GET requests for server-to-client notifications via SSE
|
|
app.get('/mcp', handleSessionRequest);
|
|
|
|
// Handle DELETE requests for session termination
|
|
app.delete('/mcp', handleSessionRequest);
|
|
console.log("Listening on port 8002");
|
|
app.listen(8002); |