Stateless MCP Removes Session Affinity Requirements for AWS Server Deployments
AWS removes session affinity from MCP — simpler scaling, but you're now responsible for idempotency and observability.
Why it matters
The latest Model Context Protocol spec eliminates protocol-level sessions and sticky-session requirements, enabling stateless server deployments and horizontal scaling. The tradeoff: application teams must now handle retries, idempotency, and state management themselves.
The key facts
10 to knowStateless MCP removes session affinity and sticky-session requirements
Enables independent request routing and horizontal scaling
Application state, retries, observability, and idempotency shift to application layer
AWS details the specification change and deployment implications
Simplifies infrastructure but increases application-layer responsibility
Latest MCP specification removes protocol-level sessions and sticky-session requirements
Enables independent request routing and simpler horizontal scaling
Application state, retries, observability, and idempotency concerns shift to other layers (caller responsibility)
AWS official technical guidance via InfoQ
Published September 25, 2026
Go to the source
InfoQ AI/MLinfoq.com
Publisher excerpt: AWS details how the latest Model Context Protocol specification removes protocol-level sessions, sticky-session requirements, and session storage for remote MCP servers. The change enables independent request routing and simpler horizontal scaling while shifting application state, retries,…