Quickstart

Get AI context for your Rails app in under 5 minutes.

Tools Reference · Recipes · Configuration · FAQ

Option A: In your Gemfile (recommended)

# 1. Add the gem
bundle add rails-ai-context --group development

# 2. Run the install generator
rails generate rails_ai_context:install

The generator asks two questions:

Which AI tools do you use? - Claude Code, Cursor, GitHub Copilot, OpenCode, Codex CLI, or all. There is no “none” choice: an empty answer, or one with no valid number, selects all five.
What should rails-ai-context write? - MCP config + context files (default), context files only (CLI mode), or MCP config only

The third answer is MCP-only: the server and the CLI answer in full, and your own CLAUDE.md, AGENTS.md and rules files are left alone. Non-interactively that is --mcp-only.

Three more prompts appear only when they apply:

Remove their generated files? - on a re-run that drops a tool you picked before. Default: keep them. A yes removes only what the gem generated, never a rule file or a line you wrote.
Install a pre-commit hook that validates Rails references? - in a git repo that has no pre-commit hook yet. Default: no.
Delete them? - in a terminal, when rule files left over from before v5.0.0 are found. Default: no.

--defaults skips every prompt and takes each default: all five tools, keep the files, MCP config + context files, no hook, keep legacy files. Every step is listed in What the install generator does.

That’s it. Your AI tool now has live access to your schema, models, routes, controllers, views, and conventions.

[!TIP] The generator is idempotent - re-running it preserves existing config and only adds new sections.

Option B: Standalone (no Gemfile entry)

# 1. Install the gem globally
gem install rails-ai-context

# 2. Navigate to your Rails app
cd your-rails-app

# 3. Run interactive setup
rails-ai-context init

# 4. Start the MCP server
rails-ai-context serve

init asks the same two questions, and the cleanup and legacy-file prompts when they apply. It has no pre-commit hook prompt and no --defaults flag, and it does not create config/initializers/rails_ai_context.rb.

Works with every Ruby version manager (rbenv, rvm, asdf, mise, chruby, system). Learn more about standalone mode →

What just happened?

The install generator created:

File	Purpose
`.mcp.json` / `.cursor/mcp.json` / `.vscode/mcp.json` / `opencode.json` / `.codex/config.toml`	MCP auto-discovery - your AI tool detects these on project open
`CLAUDE.md` + `.claude/rules/` / `.cursor/rules/` + `.cursorrules` / `.github/copilot-instructions.md` + `.github/instructions/` / `AGENTS.md`	Static context rules your AI reads
`.ai-context.json`	The same context as JSON (added to `.gitignore`)
`config/initializers/rails_ai_context.rb`	All configuration options
`.rails-ai-context.yml`	Your tool selection, and the config file for standalone mode

Verify it works

# Check AI readiness (25 diagnostic checks)
rails ai:doctor          # In-Gemfile
rails-ai-context doctor  # Standalone

# Try a tool
rails 'ai:tool[schema]' table=users
rails 'ai:tool[model_details]' model=User
rails 'ai:tool[routes]' controller=users

See it work

[!IMPORTANT] These are CLI commands. When MCP is connected, your AI calls the same tools automatically - you never type these manually.

Three commands that show immediate value:

# 1. Trace a method across your entire codebase - one call
rails 'ai:tool[search_code]' pattern="your_method_name" match_type=trace

# 2. Full-stack feature analysis - models + controllers + routes + tests
rails 'ai:tool[analyze_feature]' feature=auth

# 3. Get your app's actual conventions - not generic Rails patterns
rails 'ai:tool[conventions]'

What to do next

Open your project in your AI tool - MCP auto-discovery kicks in
Ask your AI to describe your User model - it will call rails_get_model_details instead of guessing
Read Recipes for real-world workflows that show the tools in action

Quick reference

In-Gemfile	Standalone	What it does
`rails ai:serve`	`rails-ai-context serve`	Start MCP server
`rails 'ai:tool[NAME]'`	`rails-ai-context tool NAME`	Run any tool
`rails ai:tool`	`rails-ai-context tool --list`	List all tools
`rails ai:doctor`	`rails-ai-context doctor`	Diagnostics
`rails ai:watch`	`rails-ai-context watch`	Auto-regenerate on change
`rails ai:context`	`rails-ai-context context`	Regenerate context files

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