mcp-best-practices

# 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 | Next | |-----------|---------|------| | Spec | **2025-11-25** ([specification](https://modelcontextprotocol.io/specification/latest)) | [2026-07-28 Release Candidate](https://blog.modelcontextprotocol.io/posts/2026-07-28-release-candidate/), locked 2026-05-21: stateless/sessionless overhaul (see "Spec 2026-07-28 RC Direction") | | TS SDK (stable) | **v1.29.0** (`@modelcontextprotocol/sdk`) | v2 beta published | | TS SDK (v2) | **Beta** (`2.0.0-beta.3` on npm, 2026-07-09; the `latest` dist-tag points at the beta, so a plain `npm install` resolves to the prerelease): `/server`, `/client`, `/core`, `/hono`, `/express`, `/node`, `/fastify`, `/codemod` (+ `/server-legacy`, deprecated, frozen at beta.2) | Stable ships with the final spec on 2026-07-28 | | JSON Schema | **2020-12** default (explicit `$schema` supported) | - | | Transport | **Streamable HTTP** (remote), **stdio** (local) | SSE + WebSocket removed in v2 | | Extensions | **MCP Apps** (Stable, SEP-1865), **Auth Extensions** (official) | Domain-specific WGs | | Registry | **Preview** with v0.1 API freeze since 2025-10-24 ([registry](https://modelcontextprotocol.io/registry/about)) | GA pending | **v1 imports** (production today): ```typescript import { McpServer } from "@...