# What is llms.txt (and why your site needs one)

`llms.txt` is a plain-text file at the root of your site (`https://yoursite.com/llms.txt`) that summarizes your product for large language models and AI agents. Think of it as a concise map: what you do, who it is for, and where to find machine-readable docs.

## Why it matters

- Agents and crawlers use it to **recommend your product accurately** instead of guessing from marketing copy.
- AI Agent Pages and [isitagentready.com](https://isitagentready.com) check for `llms.txt` as part of agent readiness.
- It pairs well with **MCP server cards**, **ARD manifests**, and your normal sitemap.

## Minimal example

```markdown
# Your Product Name

> One-line description of what you offer.

## For agents

- Docs: https://yoursite.com/docs
- API: https://yoursite.com/.well-known/api-catalog
- Support: support@yoursite.com

## Key pages

- [Pricing](https://yoursite.com/pricing)
- [Submit / contact](https://yoursite.com/contact)
```

Serve it as `text/plain; charset=utf-8` with a 200 response (no auth wall).

## Checklist

1. Publish `/llms.txt` on your production domain.
2. Link it from `robots.txt` or site footer (optional but helpful).
3. [Submit to AI Agent Pages](/submit) — choose the site type that matches how you sell (content, product, commerce).
4. Rescan after changes if you are already listed.

## Next steps

- [MCP server card guide](/guides/mcp-server-card)
- [Agent-ready SaaS guide](/guides/agent-ready-saas)
- [Browse the directory](/listings)