app-ads.txt checker
Enter a developer's site. We read its app-ads.txt now, list the errors, group the lines by ad network and name who holds each direct account from the networks' sellers.json.
What this checks
app-ads.txt is the developer's own list of who may sell its ad space (IAB Tech Lab). DIRECT means the developer holds the account; RESELLER, someone sells on its behalf. Account holders come from each network's public sellers.json, as last fetched. A file is a statement by the developer, not proof of what runs in an app.