mcp

# Model Context Protocol for Scala 3 This is a WIP library implementing the [Model Context Protocol](https://modelcontextprotocol.io/introduction). At the moment the library consists of three parts: 1. Code generator that uses JSON schema from MCP to implement a subset of the protocol 2. Minimal runtime to help serialising structures in JSON 3. Minimal jsonrpc runtime implementing JSONRPC 2.0 protocol Note that the jsonrpc implementation does not support cancellation, and is generally not designed for serious usage – but it's great to get things off the ground quickly! In the future, this library will provide an integration with [jsonrpclib](https://github.com/neandertech/jsonrpclib/), once that library is published for Scala Native 0.5 (or may be earlier, if someone works on that integration). ## Getting Started **Note that the library is using Scala 3.7 – which is generally fine for apps, as you can use any version of Scala above 3.7** ```scala mdoc:reset-object //> using scala 3.7.0 //> using dep com.indoorvivants::mcp-quick::latest.release import mcp.* @main def hello = val mcp = MCPBuilder .create() .handle(initialize): req => InitializeResult( capabilities = ServerCapabilities(tools = Some(ServerCapabilities.Tools())), protocolVersion = req.protocolVersion, serverInfo = Implementation("scala-mcp", "0.0.1") ) .run(SyncTransport.default) end hello ``` Save it in a `mcp.scala` file and run it with MCP Inspector: ```bash npx @modelcontextprotocol/inspector scala-cli run mcp.scala ``` For a more involved example, containing tool usage and bi-directional communication, see the [sample](./sample/src/main.scala). ## See it in action You can run the provided [sample](./sample/main.scala) using [MCP inspector](https://github.com/modelcontextprotocol/inspector) as long as you have [Scala CLI](https://scala-cli.virtuslab.org/) and [npx](https://docs.npmjs.com/cli/v9/commands/npx?v=true) installed: ```bash npx @modelcontextprotocol/inspector make run-sample ``` The sample loads and works in the MCP inspector:  And can be [configured in Claude desktop](https://modelcontextprotocol.info/docs/quickstart/user/#2-add-the-filesystem-mcp-server):