MCP Model Context Protocol
Anthropic's open protocol for connecting LLMs to tools, data, systems. Launched November 2024. Rapidly accepted as standard — OpenAI, Google adopted in 2025.
Standardizes three things: tools (LLM can call), resources (LLM can read), prompts (template library). JSON-RPC over STDIO or HTTP. Hundreds of MCP servers exist: filesystem, GitHub, Slack, Postgres, Notion, Linear. Claude Desktop + Cursor + Windsurf run MCP natively. Anthropic-controlled governance, criticized for limited open governance.