LLMs.txt
Weight: 15% of your AX score. This check verifies that your site has a /llms.txt file following the llmstxt.org specification — a Markdown file that helps AI agents understand your site's purpose and structure.
/llms.txt not found
Your site has no /llms.txt file. This is the most impactful AX file you can create — it gives AI agents a structured, human-readable summary of your site in Markdown format.
Create a llms.txt file in your site root following the llmstxt.org specification:
# Your Site Name > A brief summary of what your site does, who it's for, and what AI agents can find here. ## Sections - [About](https://your-site.com/about): Company overview - [API](https://your-site.com/api): REST API documentation - [Docs](https://your-site.com/docs): Full documentation ## API - [Users](https://api.your-site.com/users): GET /users - [Products](https://api.your-site.com/products): GET /products ## Optional - [Full LLM docs](https://your-site.com/llms-full.txt): Extended version
npx ax-init --from https://your-site.com to auto-generate an llms.txt based on your site's content.Missing H1 heading
The llmstxt.org spec requires the first line to be an H1 heading (# Your Site Name). This tells AI agents what entity the file describes.
# Your Site Name
Make sure the # is the very first character of the file, followed by a space and your site or project name.
Missing blockquote description
After the H1 heading, the spec expects a blockquote (> ...) containing a brief summary. This is the first thing an AI agent reads to understand your site.
# Your Site Name > A one-line description of what your site offers and who it's for.
Keep it concise (1-2 sentences). Think of it as a meta description optimized for AI agents rather than search engines.
Missing section headings
Your llms.txt has no ## section headings. These help AI agents navigate the content and understand its structure.
Common sections include:
## Sections— Links to main site pages## API— API endpoints and documentation## Documentation— Technical docs links## Optional— Extended resources and full LLM docs
No Markdown links
Your llms.txt contains no Markdown links ([text](url)). Links are essential — they allow AI agents to navigate from the summary to specific pages.
- [Home](https://your-site.com/): Overview and navigation - [API Docs](https://your-site.com/api): Full API reference - [Contact](https://your-site.com/contact): Get in touch
Use absolute URLs (including https://) so agents can resolve them from any context.
Minimal content
Your llms.txt has fewer than 100 characters. While there's no strict length requirement, very short files don't give AI agents enough context to understand your site.
A good llms.txt typically includes:
- H1 with your name/brand
- Blockquote summary (1-2 sentences)
- Key information (title, location, contact, etc.)
- 2-3 sections with descriptive links
- Total: 500-3,000 characters is a good range
Missing /llms-full.txt
The /llms-full.txt file is optional but recommended. It's an extended version of your llms.txt with comprehensive detail — full API documentation, complete technology lists, detailed descriptions, etc.
Think of it this way: llms.txt is the summary, llms-full.txt is the full documentation. An AI agent can choose which version to read based on its context window and needs.