dot-llm is a Ruby gem that integrates with Ruby on Rails to deliver responses optimized for large language models (LLMs) by converting HTML into a simplified Markdown format. It registers a new MIME type (text/llm) and provides a custom renderer that extracts core content from your HTML—removing extraneous elements like navigation, headers, footers, and more—while converting important HTML elements (for example, bold text) into Markdown.
Important
If you see this note it means that this gem is still a WIP and it hasn't been published yet. DO NOT USE IT IN PRODUCTION.
-
Custom LLM Response Format:
Registers a new MIME type and renderer for:llm, so controllers can respond with LLM-friendly Markdown viaformat.llm. -
Automatic Content Extraction:
Strips out extraneous HTML elements (e.g.<nav>,<header>,<footer>,<aside>,<script>,<style>) to focus on the core content. -
HTML to Markdown Conversion:
Uses ReverseMarkdown to convert HTML to Markdown—e.g., converting<b>World</b>into**World**. -
Custom Template Support:
Supports custom LLM templates (e.g..llm.md.erb), allowing you to override the default behavior if desired.
Add the following line to your application's Gemfile:
gem 'dot-llm', '~> 0.2.0'Then run:
bundle installAlternatively, install it directly using:
gem install dot-llmIn your Rails controller, include :llm in your respond_to list. For example:
class ArticlesController < ApplicationController
respond_to :html, :json, :llm
def show
@article = Article.find(params[:id])
respond_to do |format|
format.html # renders the standard HTML view
format.json { render json: @article }
format.llm # renders an LLM-optimized Markdown version
end
end
endIf no custom LLM template exists, dot-llm will render your regular HTML view, extract the main content (removing extraneous elements), and convert it to Markdown automatically.
For complete control over the LLM output, you can create a custom template. For example, place a file at:
app/views/articles/show.llm.md.erb
With content like:
# <%= @article.title %>
<%= @article.body %>
---
_Thank you for reading!_Rails will render this template for LLM requests, allowing you to tailor the Markdown output exactly as needed.
The default extraction removes elements matching the selectors: nav, header, footer, aside, script, style. You can override this behavior using the helper method:
markdown = DotLlm::Railtie.convert_html_to_markdown(your_html_string, ["nav", "header", "footer", "custom-selector"])This flexibility lets you customize which parts of your HTML should be removed before conversion.
The gem comes with an extensive RSpec suite that simulates a minimal Rails environment to test responses in HTML, JSON, and the custom LLM format.
From the gem’s root directory, run:
bundle exec rspecThe tests verify that:
- HTML requests return the full HTML (with extraneous tags intact).
- JSON requests return the expected JSON object.
- LLM requests return Markdown where extraneous tags have been removed and key HTML (e.g.
<b>World</b>) is converted to Markdown (**World**).
Contributions, bug reports, and pull requests are welcome! Please check out the GitHub repository for more details. Contributors are expected to adhere to the project's code of conduct.
This gem is available as open source under the terms of the MIT License. Author: Gaston Morixe 2025