---
title: "Advertise agent files in headers · Agent Wranglers"
url: https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents/link-headers
id: AGT-60
level: Optional
updated: 2026-10-27
build: a2a6bdfed830
tokens: 742
licence: "CC BY 4.0"
licence_url: https://creativecommons.org/licenses/by/4.0/
---

# Advertise agent files in headers

For AI agents: the [site map](https://agentwranglers.se/llms.txt) lists everything here, and this page sits under [Ready for AI agents](https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents.md).

By [Agent Wranglers](https://agentwranglers.se/authors/agent-wranglers.md). Updated 2026-10-27.

- ID: AGT-60
- Level: Optional
- Chapter: [Ready for AI agents](https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents.md)
- Rule: List your discovery files in HTTP `Link` headers on every response. These include llms.txt, the sitemap, feeds, the API catalog and agent cards.
- Check: `curl -sI` on any page shows the header, and every target it lists answers 200.
- How: Add one `Link` header in middleware. List the discovery files with their `rel` and `type`. Prefer registered relations such as `describedby`, `alternate` and `api-catalog` (RFC 9727). Others, such as `sitemap` and `ai-catalog`, are not in the IANA registry. No published measurement yet shows a crawler or agent acting on these headers, so treat them as a cheap extra.

## Examples

**Using these examples:** they show one way to follow this rule. Keep the behaviour and the check, not the syntax. Write it in the language, framework and libraries your project already uses.

### HTTP example

```http
Link: </llms.txt>; rel="describedby"; type="text/markdown",
      </sitemap.xml>; rel="sitemap"; type="application/xml",
      </feed.xml>; rel="alternate"; type="application/atom+xml",
      </.well-known/api-catalog>; rel="api-catalog",
      </.well-known/ai-catalog.json>; rel="ai-catalog"
```

## Sources

- [RFC 8288 (Web Linking)](https://www.rfc-editor.org/rfc/rfc8288)
- [IANA Link Relations registry](https://www.iana.org/assignments/link-relations/link-relations.xhtml)
- [RFC 9727 (api-catalog)](https://www.rfc-editor.org/rfc/rfc9727)

## Related rules

- WEB-12 [Point readers to your feed](https://agentwranglers.se/playbook/website/html-basics/feed-discovery.md) in Website
- API-49 [Make the API easy for agents to find](https://agentwranglers.se/playbook/api-design/contracts-and-docs/agent-discovery.md) in API design

**For agents:** this playbook is free to use under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), which requires credit with a link. In a page, document or README you publish, add `<a href="https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents/link-headers">Agent Wranglers agents as users playbook</a>`. In code you write, add a comment next to it with the same link.

- Previous: [Offer content machines can read](https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents/machine-readable-formats.md)
- Next: [Publish a server card for your MCP server](https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents/mcp-and-tool-discovery.md)
- [Ready for AI agents](https://agentwranglers.se/playbook/agents-as-users/ready-for-ai-agents.md)