@sei-js/mcp-server/dist/esm/server/transport/streamable-http.js

Model Context Protocol (MCP) server for interacting with EVM-compatible networks

import express from 'express';
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
import { getServer } from '../server.js';
export class StreamableHttpTransport {
    constructor(port = 8080, host = 'localhost', path = '/mcp') {
        this.mode = 'streamable-http';
        this.port = port;
        this.host = host;
        this.path = path;
    }
    // Note: server parameter ignored for now as this is a stateless server
    // TODO: allow creating both stateless and stateful remote MCP servers
    async start(_server) {
        this.app = express();
        this.app.use(express.json());
        this.app.use((req, res, next) => {
            res.header('Access-Control-Allow-Origin', '*');
            res.header('Access-Control-Allow-Methods', 'POST, OPTIONS');
            res.header('Access-Control-Allow-Headers', 'Content-Type');
            if (req.method === 'OPTIONS') {
                return res.sendStatus(200);
            }
            next();
        });
        this.app.post(this.path, async (req, res) => {
            try {
                // Create fresh MCP server for this request (stateless design)
                const mcpServer = await getServer();
                const transport = new StreamableHTTPServerTransport({
                    sessionIdGenerator: undefined // For stateless servers
                });
                res.on('close', () => {
                    console.log('Request closed');
                    transport.close();
                    mcpServer.close();
                });
                await mcpServer.connect(transport);
                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
                    });
                }
            }
        });
        this.server = this.app.listen(this.port, this.host, () => {
            console.error(`MCP Server ready (streamable-http transport on ${this.host}:${this.port}${this.path})`);
        });
        this.server.on('error', (error) => {
            console.error('Error starting server:', error);
        });
    }
    async stop() {
        if (this.server) {
            return new Promise((resolve) => {
                if (this.server) {
                    this.server.close(() => {
                        this.server = undefined;
                        this.app = undefined;
                        resolve();
                    });
                }
                else {
                    resolve();
                }
            });
        }
    }
}