Link Headers for AI Agents
Link headers are HTTP response fields that help AI agents discover machine-readable resources such as sitemaps, llms.txt, API catalogs, and policies.
Link Headers for AI Agents
Link headers are HTTP response fields that point clients to related resources before they parse the page body. For AI agents, they can act as a lightweight discovery layer for llms.txt, sitemaps, API catalogs, authentication metadata, and policy files.
They do not replace visible navigation or HTML links. They add a protocol-level hint that a crawler or agent can read from the response headers.
Why It Matters
AI agents often start with a URL and need to answer practical questions:
- Is there a machine-readable site summary?
- Is there an API description?
- Is there a sitemap or feed?
- Is there authentication metadata?
- Are there policies for crawlers or agents?
HTTP Link headers can expose those resources without forcing every agent to scrape page templates.
Common Discovery Targets
rel="sitemap"for XML sitemap discoveryrel="alternate"for alternate formats such as feeds or language variantsrel="describedby"for API descriptions or documentationrel="service-desc"for machine-readable API descriptionsrel="authorization-server"or related metadata links when authentication is required
SEO Guidance
Use Link headers as supporting infrastructure. The primary content still needs crawlable HTML, canonical URLs, internal links, structured data, and clear copy.
For Agent SEO, the clean pattern is:
- Keep important resources linked in HTML
- Add HTTP Link headers for machine discovery
- Keep header targets stable and indexable where appropriate
- Test the raw HTTP response, not only the rendered page