MCP Stateless Server Template

Production-ready stateless MCP server implementing the 2026-07-28 specification.

Built by Varritech | christian@varritech.com

Why This Exists

MCP just grew up. The 2026-07-28 specification retired sessions and handshakes, transforming MCP from a bidirectional stateful protocol into a request/response stateless protocol.

This template gives you a working stateless server in TypeScript that you can:

• Deploy behind a round-robin load balancer immediately

• Scale horizontally without shared storage

• Use as a reference for migrating your existing MCP servers

Related MCP server: Kroki MCP

Quick Start

npm install
npm run dev

Your server will be available at http://localhost:3000/mcp

What Changed in 2026-07-28

Key Features

✅ Stateless by default - Every request is self-describing
✅ Load balancer ready - Any request lands on any instance
✅ Cacheable responses - ttlMs and cacheScope hints included
✅ MRTR support - Handle user input requirements mid-call
✅ Authorization hardened - RFC 9207 issuer validation

Architecture

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   Client    │────▶│  Load       │────▶│   Server    │
│             │     │  Balancer   │     │  Instance   │
└─────────────┘     └─────────────┘     └─────────────┘
                                            │
                                      ┌─────────────┐
                                      │   Server    │
                                      │  Instance   │
                                      └─────────────┘

No session affinity required. No shared storage needed.

Migration Guide

If you have an existing MCP server:

1. Remove initialize/initialized handlers

2. Drop Mcp-Session-Id tracking

3. Add _meta.clientInfo parsing to each request

4. Implement server/discover RPC (optional but recommended)

5. Update response format to include ttlMs and cacheScope

See GUIDE.md for the full migration walkthrough.

License

MIT - Varritech 2026