Changelog

Source: NEWS.md

mcpr 0.0.2

• Added support for ellmer::tool
• Added MCP roclet for automatic server generation:
  • New @mcp tag for marking functions as MCP tools
  • New @type tag for specifying parameter types (string, number, boolean, array, object, enum)
  • mcp_roclet() function integrates with roxygen2 to generate complete MCP servers
  • Automatically creates inst/mcp_server.R with tool definitions and handlers
  • Supports all standard JSON Schema types and enum values
• Added support for headers for clients
• HTTP client works with Streamable HTTP servers: sends the required Accept header, reads text/event-stream responses, and tracks Mcp-Session-Id and MCP-Protocol-Version
• initialize() on a client now sends notifications/initialized and requests protocol 2025-11-25
• HTTP client timeout is now honoured in milliseconds, as documented (it was passed as seconds); pass a larger timeout for slow tools
• tools_call(), resources_read(), and prompts_get() on a client generate a request id when none is given, previously they were sent as notifications and never got a response
• serve_http() works with ambiorix 3.0.0, which removed res$set_header()

mcpr 0.0.1

Major Changes

• Added comprehensive client support for interacting with MCP servers:
  • new_client() for creating client connections to both local process and HTTP servers
  • initialize() for initializing client connections
  • tools_list() and tools_call() for discovering and using server tools
  • prompts_list() and prompts_get() for working with server prompts
  • resources_list() and resources_read() for accessing server resources
• Renamed new_mcp() (deprecated) to new_server() for clarity
• Added example implementations for both server and client
• Added client usage vignette
• Fix major issue with serve_http()

mcpr 0.0.0

• Initial CRAN submission.