mcp-spec
Model Context Protocol — Spec & Docs (modelcontextprotocol.io)
URL: https://modelcontextprotocol.io Publisher: Model Context Protocol Retrieved: 2026-07-08
Summary
The official Model Context Protocol docs define MCP as an open-source standard for connecting AI applications to external systems ("a USB-C port for AI applications"). It specifies a client-server architecture (MCP host / MCP client / MCP server), two layers (a JSON-RPC 2.0 data layer and a transport layer), the three server primitives (Tools, Resources, Prompts), client primitives (Sampling, Elicitation, Logging), and two transports (Stdio, Streamable HTTP with optional SSE). This is the open protocol, distinct from Anthropic's API MCP connector (which supports only tools over remote HTTP).