Free Tool

agents.txt Validator

Check an agents.txt discovery stub or agent-policy.json document against the v0.1 spec — structural validation with line-level errors and warnings.

Runs in your browser — nothing is uploaded

Results appear here. After the first run, validation updates live as you edit.

About the format

robots.txt governs crawling. agents.txt governs acting.

/agents.txt is a human-glanceable discovery stub that points to /.well-known/agent-policy.json, a strict, versioned descriptor of what actions an autonomous agent may attempt on a surface — under what conditions, and with what verifiable proof. Malformed policies fail closed: deny everything.

FileGoverns
robots.txtCrawling / indexing
llms.txtReading / summarisation
agents.txtActing — what an agent may do, under what conditions, with what proof