Core types and protocol definitions for the Model Context Protocol (MCP)

This library provides the core type definitions and JSON-RPC protocol layer for the Model Context Protocol (MCP). MCP is a protocol that enables seamless communication between AI models and external tools, resources, and services.

This package contains only the pure protocol types with minimal dependencies, making it suitable for building both clients and servers on any framework. For a ready-made Servant-based server, see the mcp package.

mcp-types — MCP protocol types for Haskell

Core type definitions and JSON-RPC protocol layer for the Model Context Protocol (MCP).

This package contains only the pure protocol types with minimal dependencies, Implements MCP protocol version 2025-06-18, making it suitable for building both clients and servers on any framework. For a ready-made Servant-based server, see the mcp package.

Modules

• MCP.Types — Core MCP data types: Content, Resource, Tool, Prompt, Capability, Implementation, and more.
• MCP.Protocol — JSON-RPC 2.0 message wrappers, all client/server request/response types, notification types, and protocol constants. Re-exports the jsonrpc transport types.
• MCP.Aeson — Custom Aeson parsing options used internally.

Install

build-depends:
    base
  , aeson
  , mcp-types

MCP Protocol Support

License

MPL-2.0