Authorized Supply Paths: ads.txt, sellers.json, schain

Where the money leaks: In the eleven publisher files we have taken over since 2023, between 18 and 40 percent of ads.txt lines named a seat that had not paid the publisher anything in the previous ninety days. Those lines are not neutral. Each one is a route a reseller can use to sell your inventory into a DSP that then sees your domain arriving by four paths at four prices, and buyers running supply path filters resolve that ambiguity by taking the cheapest path, which is rarely yours. How we work the file: We reconcile in three places at once and trust none of them alone. Remittance advice from each partner tells us which seats actually pay you. The partner's own sellers.json tells us how they describe you: seller_type, the seller_id, whether your relationship is filed as confidential. A sample of live bid requests tells us what the SupplyChain object carries, node by node, asi and sid, and whether complete and hp are set the way the partner claims. A seat that pays but whose sid does not match the publisher account ID in your ads.txt line is a bid that quietly fails buyer-side path checks. Then the spec work. OWNERDOMAIN and MANAGERDOMAIN set to who actually holds the ad server account, one manager per country where you have separate representation. Subdomain directives for every hostname that serves an ad and none for hostnames that do not. DIRECT and RESELLER declared truthfully. INVENTORYPARTNERDOMAIN where the content comes from a partner. For apps, app-ads.txt at the developer URL declared in the store listing, and we check the store listing itself, because that is what the crawler reads and it is usually the thing that is wrong. Serving matters as much as content: text/plain, HTTP 200, no redirect that leaves the root domain, no CDN bot rule answering the crawler with a challenge page, cache lifetime short enough that a removal takes effect this week rather than next quarter. What we will not do: We do not add a line because a partner emailed a snippet. We do not declare a partner RESELLER unless they appear in their own sellers.json with a seller_id we can see in a live supply chain. We will not file your seller record as confidential while you sell yourself as direct supply; the two statements contradict each other and buyers read both. We do not maintain declarations for inventory you neither own nor control. Who this is not for: Network and MCM parents who want more paths declared rather than fewer. Anyone whose objective is to make an arbitrage relationship look direct. If a partner has told you that removing their reseller line will cost you demand, and you find that argument persuasive, we are the wrong shop. What you get: A reconciled ads.txt and app-ads.txt per domain, ready to deploy, with every line annotated to the payment and the supply chain node that justifies it. A correction letter per partner listing what we want changed in their sellers.json, written so you can forward it unedited. A supply chain sample with mismatches marked and the revenue at risk on each. And a standing rule for who may add a line and what evidence they must produce first. The file drifts because nobody owns it, and ownership is the part that keeps the win after we leave.