Operator directory

Posterna's operator directory lists the companies that run AI agents and crawlers, their agents' User-Agent tokens, and how each one can be verified: the IP lists they publish, the reverse DNS names they document, and the Web Bot Auth key directories they sign requests with. Posterna installs use it to tell a verified agent from one that only claims to be one.

Where the data comes from

Every fact comes from a page the operator published, with its source and the date it was fetched. Nothing is invented: a token, address range or key with no published source is left out. Operators known only from the community list ai.robots.txt (MIT) stay marked as community records until they are researched.

• Source and history: packages/directory in the open-source repository, with a build report listing every fetch.
• Signed releases: /v1/directory.json and /v1/keys.json, each with a .sig file. Installs check these signatures against keys built into @posterna/core before using a release.
• Who signs requests today: the signer status board.
• License: the data is CC BY 4.0. Credit "Posterna operator directory".

PosternaDirectoryBuilder

If you see this User-Agent in your logs, it is the program that builds the directory:

PosternaDirectoryBuilder/0.1 (+https://posterna.com/directory)

• It runs once a day, from GitHub Actions, so its address is not fixed.
• It fetches only what the directory cites: operators' documentation pages, the IP lists and key directories they publish, and the ai.robots.txt list. It does not crawl or follow links from those pages.
• It follows robots.txt (RFC 9309) under the product token PosternaDirectoryBuilder, waits at least one second between requests to the same host (longer if your Crawl-delay asks for it, up to 30 seconds), stops each request after 15 seconds, and never retries.
• It does not sign its requests.

To stop it fetching from your site, add this to your robots.txt:

User-agent: PosternaDirectoryBuilder
Disallow: /

Each build lists the pages robots.txt blocked in its build report.

Corrections and listings

Operators can ask to be listed, with their key directory, on the For operators page. For a correction, or anything about the builder, email [email protected] or open an issue on GitHub.