MCP Stateless Protocol

The MCP Stateless Protocol is the request-handling model introduced in the 2026-07-28 revision of the Model Context Protocol (MCP). Each request carries the protocol information needed to process it without a long-lived protocol session. This makes MCP traffic easier to route, cache, scale, and observe through ordinary HTTP infrastructure.

Earlier MCP designs were more session-oriented. A client and server established a connection, negotiated capabilities, and could use server-to-client requests during that session. The 2026 revision removes that protocol-level session dependence and pushes application state into explicit request and response data or higher-level application storage.

The benefits include:

• compatibility with load balancers and serverless infrastructure;
• easier horizontal scaling;
• simpler retries and request tracing;
• better cacheability for safe reads;
• fewer assumptions about sticky sessions; and
• clearer separation between protocol state and application state.

Stateless does not mean the application has no state. A server can still maintain databases, user accounts, job records, resources, and authorization policy. The point is that the transport protocol no longer requires the same kind of durable connection state for every interaction.

This shift affects features such as MCP Elicitation, sampling, roots, logging, and server-to-client requests. A Multi Round-Trip Request carries a need for input in the result and lets the client retry with the answer. An MCP task gives a long-running server operation an explicit handle without restoring a transport session.

The MCP Stateless Protocol also supports enterprise deployment patterns where an LLM Gateway, API gateways, and observability tools need to inspect and route high-volume AI traffic.

The MCP project explains the stateless protocol core in its 2026-07-28 specification release.