MCP Server Ssh Rails Runner

🚀 SSH Rails Runner MCP Server

An MCP server that enables secure remote execution of Rails console commands via SSH. This server provides tools for read-only operations and strictly managed mutation operations on Rails applications in the deployment environment.

It works even better when used with Cursor. You can use Cursor Composer to pull your Rails model files as context, and then use the execute_read_only, dry_run_mutate, and execute_mutate tools to make changes to the database. There's no need to go through a complex administrator UI for data processing and analysis.

🚀 Quick Start

Example

✨ Features

• Remotely execute Rails console commands via SSH.
• Secure read-only operations.
• Dry-run capability for mutation operations.
• Execute approved mutation operations.
• Resource management for code snippets.

📦 Installation

npm install
npm run build

📚 Documentation

Configuration

Set the following environment variables:

SSH_HOST=your.remote.host
SSH_USER=your_ssh_user
SSH_PRIVATE_KEY_PATH=your_SSH_PRIVATE_KEY_PATH
RAILS_WORKING_DIR=/path/to/rails/app

Usage with Claude Desktop

Add the following to your Claude Desktop configuration:

{
  "mcpServers": {
    "ssh-rails-runner": {
      "command": "npx",
      "args": ["mcp-server-ssh-rails-runner"],
      "env": {
        "SSH_HOST": "your.remote.host",
        "SSH_USER": "your_ssh_user",
        "SSH_PRIVATE_KEY_PATH": "your_SSH_PRIVATE_KEY_PATH",
        "RAILS_WORKING_DIR": "/path/to/rails/app/root",
        "PROJECT_NAME_AS_CONTEXT": "The name of the Rails project we're working on, shown in the tool description to help the LLM.",
        "CODE_SNIPPET_FILE_DIRECTORY": "/path/to/store/code/snippets/locally"
      }
    }
  }
}

If CODE_SNIPPET_FILE_DIRECTORY is not provided, code snippets will be stored in a temporary directory (e.g., /tmp/mcp-ssh-rails-runner-code-snippets). PROJECT_NAME_AS_CONTEXT is optional and helps identify the project context for tool description.

Available Tools

The server now uses a prepare -> execute workflow:

mcp_ssh_rails_runner_prepare_code_snippet

• Parameters: name (string, file name), type (enum: "readOnly" | "mutate"), code (string, Ruby code), description (string, optional).
• Function: Save the provided Ruby code to a local file code_snippet_<name>.json, mark it as read-only or for mutation, and open the file for review.
• Returns: The file:// URI of the created snippet.

mcp_ssh_rails_runner_execute_code_snippet_read_only

• Parameters: uri (string, file:// URI from prepareCodeSnippet).
• Function: Read the code snippet from the URI, verify it's marked as readOnly, perform a security check on the code, and run it.
• Returns: The output of the Rails command.

mcp_ssh_rails_runner_execute_code_snippet_mutate

• Parameters: uri (string, file:// URI from prepareCodeSnippet).
• Function: Read the code snippet from the URI, verify it's marked as mutate, perform a security check on the code, and run it.
• Returns: The output of the Rails command.

Security Considerations

• Ensure the SSH connection is encrypted (e.g., use SSH protocol version 2).
• Avoid transmitting sensitive data over untrusted networks.
• Always perform strict input validation and sanitization when handling code snippets.
• Keep the server and client software up-to-date to prevent known security vulnerabilities.

📄 License

MIT