Rails MCP Server

A Model Context Protocol (MCP) server for interacting with Rails CLI. This server provides tools for listing Rails generators, getting detailed help, and executing Rails generators with proper validation and error handling.

Features

• List Generators: List all available Rails generators with descriptions and namespaces
• Generator Help: Get detailed help for specific generators including options and usage
• Execute Generators: Run Rails generators with arguments and options
• Multi-Project Support: Work with multiple Rails applications simultaneously
• Input Validation: Comprehensive input validation using Zod schemas
• Error Handling: Robust error handling with informative error messages
• Caching: Built-in caching for improved performance

Installation

npm install @ruby-mcp/rails-mcp

Usage

Standalone

npx @ruby-mcp/rails-mcp

With Project Configuration

npx @ruby-mcp/rails-mcp --project myapp:/path/to/rails/app

Multiple Projects

npx @ruby-mcp/rails-mcp \
  --project main:/path/to/main/app \
  --project api:/path/to/api/app

Available Tools

list_generators

Lists all available Rails generators in a Rails project.

Input Schema:

• project (optional): Project name to use

Example:

{
  "project": "myapp"
}

get_generator_help

Gets detailed help for a specific Rails generator.

Input Schema:

• generator_name (required): Name of the generator
• project (optional): Project name to use

Example:

{
  "generator_name": "model",
  "project": "myapp"
}

generate

Executes a Rails generator with specified arguments and options.

Input Schema:

• generator_name (required): Name of the generator
• arguments (optional): Array of arguments to pass to the generator
• options (optional): Object of options to pass to the generator
• project (optional): Project name to use

Example:

{
  "generator_name": "model",
  "arguments": ["User", "name:string", "email:string"],
  "options": {
    "migration": true,
    "timestamps": true
  },
  "project": "myapp"
}

Requirements

• Node.js 18+
• Rails application with the rails command available in PATH
• Ruby and Bundler installed

Development

Setup

# Install dependencies
pnpm install

# Build the package
pnpm build

# Run tests
pnpm test

# Run type checking
pnpm typecheck

# Run linting
pnpm lint

Project Structure

src/
├── api/
│   └── rails-client.ts     # Rails CLI command execution
├── tools/
│   ├── generators.ts       # List generators tool
│   ├── generator-help.ts   # Generator help tool
│   └── generate.ts         # Execute generator tool
├── utils/
│   └── validation.ts       # Input validation utilities
├── schemas.ts              # Zod validation schemas
├── types.ts               # TypeScript type definitions
├── project-manager.ts     # Multi-project support
└── index.ts              # Main server entry point

License

ISC