Agent Integration (MCP)

Connect coding agents to any Ruby project — gems, Sinatra apps, plain scripts — so they can query the database, inspect models, read logs, run guarded commands, and run tests with structured results.

What is ask-ruby-harness-mcp?

The Model Context Protocol (MCP) is an open standard for connecting AI agents to external tools. ask-ruby-harness-mcp exposes the six ask-ruby-harness tools as MCP tools over stdio, so any MCP-compatible coding agent (Claude Code, Cursor, ZCode, …) can use them without manual configuration.

The server serves the project in its working directory — start it from the project root you want it to manage. There is no Rails boot and no app code to load; the tools connect to the database lazily only when used.

Installation

gem install ask-ruby-harness-mcp

or add to your Gemfile (if you bundle it with the project):

gem "ask-ruby-harness-mcp"

Usage

Run from your project root:

cd my-ruby-project
ask-ruby-harness-mcp

Configure in your agent’s MCP config:

{
  "mcp": {
    "servers": {
      "ask-ruby-harness-mcp": {
        "type": "stdio",
        "command": "ask-ruby-harness-mcp",
        "cwd": "/path/to/my-ruby-project"
      }
    }
  }
}

For ZCode, the same server is registered per-workspace in <project>/.zcode/config.json:

{
  "mcp": {
    "servers": {
      "ask-ruby-harness-mcp": {
        "type": "stdio",
        "command": "ask-ruby-harness-mcp",
        "cwd": "/path/to/my-ruby-project"
      }
    }
  }
}

Monorepos

Point the server at the monorepo root — run_tests with a file: inside a subproject (a directory with its own Gemfile/Rakefile) runs that project’s suite:

{
  "mcp": {
    "servers": {
      "ask-ruby-harness-mcp": {
        "type": "stdio",
        "command": "ask-ruby-harness-mcp",
        "cwd": "/path/to/monorepo"
      }
    }
  }
}

Rails?

For Rails apps, use the Rails edition: Agent Integration (MCP) covers ask-rails-harness-mcp, which boots your app and adds RouteInspector (plus the engine’s other Rails-native tooling).