llms_txt

Generate offline llms.txt files from your Elixir project's dependency documentation.

llms_txt provides a mix llms.txt task that fetches the HTML hexdocs for every Hex dependency at its installed version, converts each page to Markdown with htmd, and writes one llms.txt per package:

priv/llms/<package>/<version>/llms.txt

These plain-text docs are handy to keep checked in for AI assistants and other tools that work better with local, offline documentation.

Installation

Add it as a dev-only dependency in the project whose dependencies you want to document:

def deps do
  [
    {:llms_txt, "~> 0.1.0", only: [:dev], runtime: false}
  ]
end

Or track the latest unreleased changes straight from GitHub:

def deps do
  [
    {:llms_txt, github: "fuww/llms_txt", only: [:dev], runtime: false}
  ]
end

The task ships inside the package, so once it is compiled mix llms.txt becomes available in your project — no extra setup needed.

Usage

# Fetch hexdocs and (re)generate priv/llms for the current dependencies
mix llms.txt

# Write to a different directory
mix llms.txt --output doc/llms

# Skip the hex.docs fetch and only re-convert docs already fetched locally
mix llms.txt --no-fetch

The task reads the calling project's mix.lock, so it always documents the versions actually locked in that project. Git and path dependencies are skipped (they have no HexDocs).

After generating, it prunes stale output: outdated version directories and packages that are no longer dependencies are removed, so the output directory always mirrors the current lock file. Re-run mix llms.txt after updating packages to keep the docs in sync.

How it works

Module	Responsibility
Mix.Tasks.Llms.Txt	Orchestration: option parsing, hex.docs fetch, concurrency, reporting.
LlmsTxt	Lockfile + filesystem: locating packages, the hexdocs cache, writing and pruning.
LlmsTxt.Converter	Pure HTML → Markdown conversion (chrome stripping, escape handling).

Development

mix deps.get
mix test
mix format