MCP server for Rails app introspection. Exposes all ask-rails tools over the Model Context Protocol.

Coding agents like Claude Code, Cursor, or any MCP-compatible client can connect to inspect your Rails schema, query your database, read models, and more — all through the same tools ask-rails uses internally.

bundle add ask-rails-mcp

Run from your Rails app root:

cd my-rails-app
ask-rails-mcp

This boots your Rails app and starts an MCP stdio server. Configure in ~/.zcode/cli/config.json (or your agent's MCP config):

{
  "mcp": {
    "servers": {
      "ask-rails-mcp": {
        "type": "stdio",
        "command": "ask-rails-mcp",
        "args": []
      }
    }
  }
}

Mount in config/routes.rb behind your existing auth:

Rails.application.routes.draw do
  authenticate :user, ->(u) { u.admin? } do
    post "ask/mcp", to: "ask/rails/mcp#handle"
  end
end

Then configure any MCP-compatible agent:

{
  "mcp": {
    "servers": {
      "ask-rails-mcp": {
        "type": "http",
        "url": "https://myapp.com/ask/mcp"
      }
    }
  }
}

The agent discovers 9 tools automatically:

The MCP endpoint uses the same Ask::Rails::Auth system as the chat UI:

Ask::Rails::Auth.check = -> {
  redirect_to main_app.login_path unless current_user&.admin?
}

All ask-rails safety features apply automatically:

• Permissions — access modes (:read_only, :ask_before_changes, :full_access)
• Command allowlists — allowed_commands / denied_commands for RunCommand
• Write guards — INSERT/UPDATE/DELETE blocked by QueryDatabase
• Audit log — every tool call recorded in ask_audit_logs

bundle exec rake test

MIT