SRI / MCP-0.13 / Changes 

0.13  2026-06-22
  - Switched from JSON::Valdiator to JSON::Schema::Tiny for better portability.

0.12  2026-06-19
  - Fixed bug in MCP::Server::Transport::Stdio where the server could disconnect when reading from Windows pipes,
    such as when spawned by Claude Desktop.

0.11  2026-06-19
  - Added OAuth scope support, so MCP servers can act as OAuth 2.0 resource servers.
  - Added scopes attribute to MCP::Primitive, and therefore to MCP::Tool, MCP::Prompt, and MCP::Resource.
  - Added scopes and insufficient_scope attributes, and a has_scope method, to MCP::Server::Context.
  - Added auth and metadata_url attributes to MCP::Server::Transport::HTTP.
  - Added headers attribute to MCP::Client.
  - Added oauth_metadata method to MCP::Server.
  - Added INSUFFICIENT_SCOPE constant to MCP::Constants.

0.10  2026-05-06
  - Added opt-in server-to-client streaming and session termination to the HTTP transport. Not compatible with
    pre-forking web servers.
  - Added support for list_changed notifications.
  - Added support for progress notifications.
  - Added MCP::Primitive class.
  - Added MCP::Server::Context class.
  - Added MCP::Server::Session class.
  - Added heartbeat, session_timeout, sessions, and streaming attributes, and a notify method, to
    MCP::Server::Transport::HTTP.
  - Added notify method to MCP::Server::Transport::Stdio.
  - Added notifications method to MCP::Server::Transport.
  - Added notify_all method to MCP::Server::Transport::HTTP and MCP::Server::Transport::Stdio.
  - Added notify_list_changed method to MCP::Server.
  - Added delete_session method to MCP::Client.

0.08  2026-02-17
  - Added support for tool annotations. (d3flex)

0.07  2026-01-16
  - Fixed bug in MCP::Prompt where text prompts had the wrong format.

0.06  2025-12-05
  - Protocol version is now 2025-11-25.
  - Added support for resources.
  - Added support for audio and resource results.
  - Added support for sessions specific prompt, resource, and tool lists.
  - Added MCP::Resource class.
  - Added read_resource and list_resources methods to MCP::Client.
  - Added resource method to MCP::Server.
  - Added audio_result and resource_link_result methods to MCP::Tool.
  - Added prompts, resources, and tools events to MCP::Server.

0.05  2025-08-28
  - Added support for prompts.
  - Added MCP::Prompt class.
  - Added get_prompt and list_prompts methods to MCP::Client.
  - Added prompt method to MCP::Server.

0.04  2025-08-04
  - Added support for structured content.
  - Added output_schema attribute to MCP::Tool.
  - Added structured_result method to MCP::Tool.

0.03  2025-08-01
  - Added image_result method to MCP::Tool.
  - Improved streaming HTTP transport to use SSE for async responses.

0.02  2025-08-01
  - Fixed support for tool calls without arguments.

0.01  2025-08-01
  - First release.