The 2025-03-26 specification is now available.

• Updated Schema
• Changelog since 2024-11-05

Major Changes:

• Added a comprehensive authorization framework based on OAuth 2.1 (PR #133)
• Added support for JSON-RPC batching (PR #228)
• Added comprehensive tool annotations for better describing tool behavior, like whether it is read-only or destructive (PR #185)
• Replaced the previous HTTP+SSE transport with a more flexible Streamable HTTP transport (PR #206)

Other schema changes:

• Added message field to ProgressNotification to provide descriptive status updates (related: Enhancement to support IProgress #111)
• Added support for audio data, joining the existing text and image content types
• Added completions capability to explicitly indicate support for argument autocompletion suggestions