ExMCP Test Server

An MCP (Model Context Protocol) server implementation in Elixir that provides a test implementation for experimenting with the protocol.

Features

• JSON-RPC 2.0 compliant server implementation
• Standard MCP protocol methods supported
• Pluggable validation and middleware pipeline
• Schema-driven request/response validation
• OpenRPC specification included

Architecture

The server is built using:

• PhxJsonRpc for the RPC layer
• ExJsonSchema for schema validation
• Jason for JSON encoding/decoding

Development

Requirements:

• Elixir 1.14+
• Mix

Install dependencies:

mix deps.get

Run tests:

mix test

API Documentation

The server implements the following MCP methods:

initialize - Initialize the server
notifications/initialized - Handle initialization notification

prompts/list - List available prompts
resources/list - List available resources

tools/list - List available tools
tools/call - Call a specific tool

The OpenRPC specification can be found in priv/static/mcp-openrpc.json.

Usage

Run the server locally:

mix run --no-halt

Configuration

The best way to run the model is to generate a release with

mix release

and add it to to your claude_desktop_config.json:

{
  "mcpServers": {
    "ex-mcp-test": {
      "command": "path/to/your/realease/bin/my_app",
      "args": [
        "start"
      ]
    }
  }
}

License

This project is licensed under the MIT License - see the LICENSE file for details.