Hugging Face's MCP Lead Explains the Protocol's Journey to Stateless Transport

Shawn, who leads MCP at Hugging Face and co-chairs the transport working group, walks through the evolution of MCP transports—from early local setups to Streamable HTTP and the stateless July release. The talk covers the practical challenges of remote MCP in production, how the community collaborated on protocol improvements, and what the new release means for SDK maintainers and developers.

■ Early MCP and the Shift to Remote Transport
- Early workflow: installing servers from NPM or GitHub, editing JSON config, and connecting locally
- LSP-inspired one-to-one client/server assumptions and why the initial remote transport was impractical
- March release of Streamable HTTP and the user-experience impact of a single URL
- Production challenges: session management, elicitation timeouts, and protocol overhead (73 messages per tool call in June data)

■ The Stateless July Release
- Community collaboration involving Anthropic, Microsoft, and Google contributors
- Removal of lifecycle handshakes and initialization calls, plus built-in list caching
- New call design pattern, HTTP-level routing visibility, and deprecation policy
- SDK maintenance effort that enabled over 50% of tool calls to move to the new protocol

■ Adoption and Deployment Guidance
- Migration status across Anthropic, OpenAI, Hugging Face chat products, and other clients
- SDK version upgrades, enabling list caching, and reconsidering discovery endpoints
- Optimistic connection handling versus pessimistic error handling
- Using MCP to move computation and storage access to where large datasets reside, aided by HTTP routing

Recommended for developers and teams working with MCP servers or agent tools. It helps you understand what changed in the protocol, assess your own migration timeline, and plan concrete steps for upgrading SDKs and adopting new transport features.