February 2026 monthly summary for modelcontextprotocol/rust-sdk: Delivered OAuth 2.1 Compliance and Enhanced Authorization Flow with RFC 8707 resource parameter support, PKCE verification, and progressive scope upgrades, along with robust error handling for insufficient scopes. Implemented new public types (AuthClient, ScopeUpgradeConfig, WWWAuthenticateParams), enhanced streamable HTTP client error signaling, and established groundwork for future scope upgrade flows. Fixed AS metadata discovery issues and improved authorisation tests and dev tooling.

May 2025: Delivered Authorization Draft Standardization and Security Clarifications for the dandavison/modelcontextprotocol-modelcontextprotocol repository. The work standardizes references to OAuth 2.0 specifications within the authorization draft and clarifies security considerations, improving interoperability and strengthening security posture for downstream integrations. A focused commit (59a0eb58826978fdd134f8fdddfdc60e3626c4fa) performed targeted cleanups and standardizations to the draft, enhancing readability and maintainability.