Xsmcp

🚀 xsMCP

xsMCP is a small MCP SDK for quickly building clients/servers. It addresses the issues of large size and unnecessary dependencies in existing SDKs, offering a lightweight and flexible alternative.

🚀 Quick Start

This project is actively under development. Stay tuned for more updates!

✨ Features

Why was this project created?

@modelcontextprotocol/sdk is bulky and depends on libraries like zod and express, which you may not need at all. Similar to xsAI, xsMCP doesn't force you to use a specific server or schema library and is very lightweight.

Development Roadmap

Our current goal is to support streaming HTTP client/server functionality, with lower priority given to Stdio support.

Compatibility

xsMCP v0.1 is customized for the 2025-03-26 version and is not backward-compatible.

HTTP Server Structure

@xsmcp/server-http is based on Web standards rather than Express.

💻 Usage Examples

Basic Usage

import { createServerAdapter } from '@whatwg-node/server'
import { createHttpServer } from '@xsmcp/server-http'
import { createServer as createMcpServer } from '@xsmcp/server-shared'
import { createServer } from 'node:http'

import * as tools from '...'

const s = createMcpServer({ ...options })

for (const tool of tools) {
  s.addTool(tool)
}

const server = createHttpServer(s)

// (req: Request) => Promise<Response>
type ServerFetch = typeof server.fetch

// node.js
const httpServer = createServer(createServerAdapter(server.fetch))
httpServer.listen(3000)

// next.js
export const POST = router.fetch

// cloudflare workers, bun
export default server

Advanced Usage

It can be used independently or combined with frameworks like hono, elysia, and itty-router for more features:

import { createHttpServer } from '@xsmcp/server-http'
import { createServer as createMcpServer } from '@xsmcp/server-shared'
import { Elysia } from 'elysia'
import { Hono } from 'hono'
import { AutoRouter } from 'itty-router'

import * as tools from '...'

const s = createMcpServer({ ...options })

for (const tool of tools) {
  s.addTool(tool)
}

const server = createHttpServer(s)

// hono
new Hono()
  .post('/mcp', ({ req }) => server.fetch(req.raw))

// elysia
new Elysia()
  .post('/mcp', ({ request }) => server.fetch(request))

// itty-router
AutoRouter()
  .post('/mcp', req => server.fetch(req))

This server is very lightweight as it doesn't depend on any server frameworks. For simplicity, it only returns JSON responses and doesn't support SSE (Server-Sent Events).

📄 License

This project uses the MIT license. The license information for third-party projects is as follows:

• @whatwg-node/server
• hono.dev