A file listing every company authorised to sell advertising space on your site, so buyers can verify they're buying real inventory.
Ad fraud thrives on impersonated inventory. ads.txt lets exchanges cross-check a seller's claim against your own public declaration before money changes hands.
A genuine IAB Tech Lab standard, widely enforced by ad exchanges since 2017.
Site root: example.com/ads.txt
Fill this in and download ads.txt directly — the same generator lives in the full builder alongside the other 15 files.