The option is relevant to legacy MCP clients using protocol versions 2025-11-25 and earlier; requests using MCP 2026-07-28 are sessionless regardless of the flag. In legacy stateless mode, server-to-client requests and SSE resumability are unavailable, while request-scoped progress remains supported.
The setting changes transport behavior, not application persistence. Agno conversation history and run state remain stored separately, and deployments with multiple replicas still need shared application storage and run coordination. The linked SQLite configuration is presented as a local-development example.