Model Context Protocol

• 2026-07-28 makes MCP stateless: the initialize handshake and Mcp-Session-Id are gone, and every request carries its protocol version and client capabilities in _meta.
• Servers must implement server/discover to advertise supported versions, capabilities and identity.
• Server-initiated requests (sampling, elicitation, roots) are replaced by the Multi Round-Trip Request pattern: the server returns input_required and the client retries with answers.
• Roots, Sampling and Logging are deprecated, as is OAuth Dynamic Client Registration in favour of Client ID Metadata Documents.
• Tasks moved from the core spec into an official extension (io.modelcontextprotocol/tasks).
• The official registry at registry.modelcontextprotocol.io lists published servers with their packages and remote endpoints.

Any time an agent needs to call an API, read a database or act in a SaaS product. Prefer remote Streamable HTTP servers with OAuth over local servers holding static API keys.