hs-mcp

# MCP-Haskell (hs-mcp) A Haskell implementation of the [Model Context Protocol (MCP)](https://modelcontextprotocol.io/). ## Overview MCP-Haskell (hs-mcp) provides a Haskell implementation of the Model Context Protocol, allowing Haskell applications to expose tools, resources, and prompts to MCP-compatible clients like Claude. Key features: - Full implementation of MCP protocol - StdIO transport for local process communication - JSON-RPC messaging - Support for resources, tools, and prompts - Comprehensive test suite ## Installation ```bash # Clone the repository git clone github.com:buecking/hs-mcp.git cd hs-mcp # direnv # echo 'use flake' > .envrc direnv allow # nix nix develop # Build the project cabal build ``` ## Usage ### Creating a simple server ```haskell import Network.MCP.Server import Network.MCP.Types import Network.MCP.Server.StdIO main :: IO () main = do -- Create server let serverInfo = Implementation "my-server" "1.0.0" serverCapabilities = ServerCapabilities { resourcesCapability = Just $ ResourcesCapability True , toolsCapability = Just $ ToolsCapability True , promptsCapability = Nothing } server <- createServer serverInfo serverCapabilities -- Register resources (optional) let resource = Resource { resourceUri = "my://resource" , resourceName = "My Resource" , resourceDescription = Just "Description" , resourceMimeType = Just "text/plain" , resourceTemplate = Nothing } registerResources server [resource] -- Register resource read handler registerResourceReadHandler server $ \request -> do -- Implement resource reading logic ... -- Register tools (optional) let tool = Tool { toolName = "my-tool" , toolDescription = Just "My tool" , toolInputSchema = "{...}" -- JSON schema } registerTools server [tool] -- Register tool call handler registerToolCallHandler server $ \request -> do -- Implement tool execution logic ... -- Start the server with StdIO transport runServerWithSTDIO server ``` ### Example Server The project includes an example echo server that demonstrates the MCP functionality: ```bash # Build and run the example server cabal run mcp-echo-server ``` You can test it with the [MCP Inspector](https://github.com/modelcontextprotocol/inspector) or Claude Desktop. ## Testing Run the test suite: ```bash cabal test ``` ## Protocol Compatibility This implementation follows the [Model Context Protocol specification](https://spec.modelcontextprotocol.io/) and is compatible with: - Claude Desktop - MCP Inspector - Other MCP clients following the specification ## Project Structure - `src/Network/MCP/Types.hs` - Core MCP types - `src/Network/MCP/Transport/` - Transport implementations - `src/Network/MCP/Server/` - Server implementation - `Examples/` - Example implementations - `Test/` - Test suite ## Contributing Contributions are welcome! Please feel free to submit a Pull Request. ## License This project is licensed under the BSD-3-Clause License - see the LICENSE file for details.