- [ Home ](/) / - [ How to create llms.txt ](/how-to-create/) / - Ruby on Rails # llms.txt in Ruby on Rails Rails serves the public/ folder at the site root. Add llms.txt there, or generate it from a controller if the content is dynamic. Last updated: July 26, 2026 ## Two approaches Rails can serve `llms.txt` two ways: a static file in `public/` (simplest), or a controller action that builds the file from your data. Use the static file unless the content must reflect live records. ## Method 1: static file in public/ Everything in `public/` is served at the domain root. A file at `public/llms.txt` resolves to `/llms.txt`. - Create the file: `touch public/llms.txt` - Write your content (see the [how-to guide](/how-to-create/)): ``` # Your App Name > One-sentence description of your app for LLM context. ## Core pages - [Home](https://yourdomain.com/): what this app does. - [Pricing](https://yourdomain.com/pricing/): plans and limits. - [Docs](https://yourdomain.com/docs/): developer documentation. ``` ## Method 2: a controller action To generate the file dynamically, add a route and a controller that renders plain text: ``` # config/routes.rb get "/llms.txt", to: "llms#show" # app/controllers/llms_controller.rb class LlmsController Description of your app.\n\n## Core pages\n\n" body += pages.map { |p| "- [#{p.title}](#{page_url(p)}): #{p.summary}" }.join("\n") render plain: body, content_type: "text/plain" end end ``` ## Serving static files in production ⚠ public_file_server By default Rails does not serve public/ in production; a fronting web server or CDN does. If Rails itself must serve the file (e.g. on some PaaS), set config.public_file_server.enabled = true or the RAILS_SERVE_STATIC_FILES environment variable. The controller method (Method 2) is served by Rails regardless of this setting. ## Verifying the setup ``` curl -sI https://yourdomain.com/llms.txt | grep -i content-type # expect: content-type: text/plain ``` Using Laravel instead? See the [Laravel guide](/llms-txt-laravel/). For a fuller export of page content, add [`llms-full.txt`](/llms-full-txt/). ## Sources - [ Rails guides, configuring (public_file_server) ](https://guides.rubyonrails.org/configuring.html) - [ llmstxt.org, spec reference ](https://llmstxt.org/) On this page - [ Two approaches ](#overview) - [ Method 1: static file in public/ ](#public) - [ Method 2: a controller action ](#controller) - [ Serving static files in production ](#production) - [ Verifying the setup ](#verify)