MCP Server: SSH Rails Runner

What is MCP Server: SSH Rails Runner?

An MCP server that enables secure remote execution of Rails console commands via SSH. It provides tools for both read-only operations and carefully managed mutations in a deployed Rails environment. The server is designed to work with Cursor, allowing AI-assisted database changes through a Prepare → Execute workflow.

How to use MCP Server: SSH Rails Runner?

Install with npm install && npm run build, then configure environment variables SSH_HOST, SSH_USER, SSH_PRIVATE_KEY_PATH, and RAILS_WORKING_DIR. Optionally set PROJECT_NAME_AS_CONTEXT and CODE_SNIPPET_FILE_DIRECTORY. Add the server to Claude Desktop configuration using the npx mcp-server-ssh-rails-runner command. Use the three provided tools: prepare_code_snippet to save and review Ruby code, execute_code_snippet_read_only for safe read-only operations, and execute_code_snippet_mutate for approved mutations.

Key features of MCP Server: SSH Rails Runner

• Remote Rails console execution over SSH
• Safe read-only operations with safety checks
• Dry-run capability for mutations
• Prepare—Execute workflow for code snippets
• Resource management for saved code snippets

Use cases of MCP Server: SSH Rails Runner

• Performing read-only data analysis on a live Rails database via Cursor Composer
• Applying user-confirmed database mutations after reviewing prepared code snippets
• Automating complex Rails console tasks without manual SSH login
• Integrating AI coding assistants with remote Rails environments

FAQ from MCP Server: SSH Rails Runner

What transport or authentication does the server use?

It uses SSH authentication via a private key, configured through SSH_USER, SSH_HOST, and SSH_PRIVATE_KEY_PATH environment variables.

Where are code snippets stored?

By default in a temporary directory (/tmp/mcp-ssh-rails-runner-code-snippets). You can set CODE_SNIPPET_FILE_DIRECTORY to a custom path.

How does the server prevent accidental mutations?

It uses a two-phase Prepare → Execute workflow. Read-only executions include a safety check; mutation executions require explicit user confirmation after reviewing the prepared code snippet file.

What runtime dependencies are required?

Node.js and npm are required for installation. The remote server must have SSH access and a Rails environment available at the configured working directory.

What limits exist for code execution?

Only code saved via prepare_code_snippet and marked as readOnly or mutate can be executed. The server performs a safety check for read-only operations but not for mutations—the user must review code before mutating.