Rails AI Context MCP server

rails-ai-context

Give your AI coding assistant ground truth about your Rails app

:star: If this gem saves you a correction loop, star it on GitHub!

Why • Features • Getting started • Usage • Tools • Configuration • Documentation

rails-ai-context is a Ruby gem that turns your Rails app into the source of truth for AI coding assistants. Instead of guessing your schema, associations, routes and conventions from training data, the assistant asks your app: 45 read-only tools served over MCP or run from the CLI, plus generated context files for Claude Code, Cursor, GitHub Copilot, OpenCode and Codex CLI.

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Nothing to add to your Gemfile if you don't want to. gem install rails-ai-context, then rails-ai-context init inside any Rails app. It also works on an app that won't boot: pass --no-boot and every tool answers from the source files.

Why

You have seen your assistant do these:

• Write a migration for a column that already exists.
• Call user.posts when the association is user.articles.
• Scaffold tests with FactoryBot in a fixture-based suite.
• Miss a before_action inherited from a parent controller, then wonder why auth fails.
• Add a gem you already have, or call an API from one you don't.
• Invent a method that isn't in the codebase.

You catch it, fix it, re-prompt, and something next to it breaks. The tokens are cheap; the correction loop is what costs you the afternoon. This gem removes the guess at the source.

Shortened. The full README is on GitHub.