Mistral Codestral MCP Server

An MCP server implementation for the Mistral Codestral API, providing code completion, bug fixing, and test generation capabilities.

Features

• Code completion with Mistral’s Codestral model
• Bug detection and fixing
• Automated test generation
• Support for multiple programming languages
• Rate limiting and error handling
• Resource access for code files
• Fill-in-the-Middle (FIM) completion support
• Comprehensive input validation using Zod schemas

Installation

1. Clone this repository

2. Install dependencies:

   npm install
   

3. Copy .env.example to .env and add your Mistral API key:

   cp .env.example .env
   

4. Build the project:

   npm run build
   

Usage

Start the server:

npm start

Configuration

Add your Mistral API key to the .env file:

MISTRAL_API_KEY=your_api_key_here

Available Tools

code_completion

Process code for completion, bug fixing, or test generation:

Parameters:

• code (string, required): The code to process
• language (string, optional): Programming language
• task (string, required): One of:
  • "complete": Code completion
  • "fix": Bug fixing
  • "test": Test generation
  • "fim": Fill-in-the-Middle completion

API Details

The server supports two main Mistral models:

• codestral-latest: Default model for code-related tasks
• codestral-mamba-latest: Alternative model with Mamba architecture

Features include:

• Automatic rate limiting (100ms minimum between requests)
• 30-second timeout for API calls
• Comprehensive error handling for API responses
• Response validation using Zod schemas
• Automatic extraction of code blocks from responses
• Debug logging for API interactions

Development

Run in development mode with auto-reloading:

npm run dev

Run tests:

npm test

Error Handling

The server implements comprehensive error handling:

• API errors are properly caught and formatted
• Rate limiting is implemented
• Input validation using Zod schemas
• Proper error propagation to clients
• Specific error messages for common issues:
  • Authentication failures
  • Rate limit exceeded
  • Server errors
  • Invalid input validation

Resource Access

The server provides access to code files through the file://code resource URI, allowing integration with workspace files.

License

MIT