Specification

Model Context Protocol Specification

The Model Context Protocol (MCP) is an open protocol that enables seamless integration between LLM applications and external data sources and tools. This section contains the detailed technical specifications for implementing the protocol.

Available Versions

MCP is under active development. The following specifications are available:

Current version:

Specification (Latest) Specification (Previous) Specification (Older) Specification (Legacy)

Version History

  • 2026-07-28 - Latest

    • Stateless protocol with per-request version and capability metadata
    • Removed protocol-level sessions and the initialization handshake
    • Added mandatory server/discover capability discovery
    • Introduced Multi Round-Trip Requests (MRTR)
    • Moved Tasks from the core protocol to an official extension

  • 2025-11-25 - Previous Stable

    • OpenID Connect Discovery support
    • Icons metadata for tools/resources/prompts
    • Incremental scope consent
    • URL mode elicitation support
    • Sampling tool calling support
    • OAuth Client ID metadata documents
    • Experimental Tasks support

  • 2025-06-18 - Older Stable

    • Removed JSON-RPC batching support
    • Structured tool output
    • OAuth Resource Server classification
    • Resource Indicators (RFC 8707)
    • Elicitation feature support
    • Resource links support

  • 2024-11-05 - Legacy

    • Initial stable version

Put the specification into practice