Supply chain · also called DIRECT
Direct seller
A direct seller is an ad system account that the publisher itself controls and gets paid through directly, marked DIRECT in the publisher's ads.txt file.
A DIRECT line in ads.txt means the publisher (or the entity that owns the site or app) holds the account in that SSP or exchange and receives the money directly. There is no intermediary between the publisher and the ad system for that path.
Buyers generally prefer direct paths. They carry fewer fees, shorter schains, less bid duplication and lower fraud risk. Many supply path optimization policies favour or require DIRECT relationships, and a DIRECT entry should correspond to a PUBLISHER seller type in the SSP's sellers.json.
Mislabelling is a known problem. Some intermediaries have claimed DIRECT status for accounts they control, which can mislead buyers. Cross-checking ads.txt against sellers.json, and treating mismatches as a red flag, helps spot this.
Think of it like this
A direct seller is like buying vegetables at the farm gate from the farmer who grew them, rather than from a trader.
An example
A publisher's ads.txt lists "ssp-a.com, pub-778, DIRECT". SSP A's sellers.json shows pub-778 as the publisher's own company with seller_type PUBLISHER: a consistent direct path.
Related terms
Reseller
A reseller is a company authorised to sell a publisher's ad inventory through an ad system account that it controls, rather than the publisher's own account, and labelled RESELLER in ads.txt.
ads.txt
ads.txt (Authorized Digital Sellers) is a public text file on a website's domain listing which ad sellers and accounts are authorised to sell that website's ad inventory.
sellers.json
sellers.json is a public file in which SSPs and exchanges list their seller accounts, naming who owns each one and whether it is a publisher or an intermediary.
Supply path optimization (SPO)
Supply path optimization (SPO) is a buyer's practice of choosing the most direct, cheapest and most trustworthy routes to the same inventory, and cutting unnecessary resellers and duplicate paths.
SupplyChain object (schain)
The SupplyChain object (schain) is a field in OpenRTB bid requests that lists, in order, every seller or intermediary that handled the impression on its way from the publisher to the buyer.