mcp-best-practices
Installation
SKILL.md
MCP Best Practices
Decision reference for building production MCP servers with the TypeScript SDK. Not a tutorial - assumes you already have a working server and need to make it correct, fast, and secure.
Quick Reference
| Component | Current | Notes |
|---|---|---|
| Spec (released) | 2026-07-28 (specification) | Stateless/sessionless overhaul - see "Spec 2026-07-28" below and references/spec-2026-07-28.md |
| Spec (still deployed) | 2025-11-25 | What most shipped clients and servers actually speak today; the v2 SDK's default |
| TS SDK (current) | v2.0.0 (2026-07-27), nine packages in lockstep: /server, /client, /core, /hono, /express, /node, /fastify, /codemod, /server-legacy |
Speaks 2025-era by default; 2026-07-28 is opt-in |
| TS SDK (legacy) | v1.30.0 (@modelcontextprotocol/sdk) |
Bug + security fixes for >=6 months after v2 GA; source on the v1.x branch |
| JSON Schema | 2020-12 default (2019-09 / draft-07 accepted since v2.0.0) | - |
| Transport | Streamable HTTP (remote), stdio (local) | SSE + WebSocket removed in v2 |
| Extensions | MCP Apps (Stable, SEP-1865), Auth Extensions (official), Tasks (ext-tasks) | Domain-specific WGs |
| Registry | Preview with v0.1 API freeze since 2025-10-24 (registry) | GA pending |