ADS.txt and Sellers.json – benefits for the publisher

why it is so important to implement them

Ads.txt and Sellers.json aren’t new to the programmatic industry. If you’re a publisher you’re most likely familiar with the terms and probably already adopted the initiative. We have covered this topic before, so we will briefly remind you of the basics.

ADS.txt and Sellers.json and their benefit for the publisher

What is ads.txt?

Authorized Digital Sellers or ADS.txt was introduced by IAB Tech Lab a few years ago. Ads.txt is a text file for publishers to list their authorized digital sellers in, in order to fight against fraud and misrepresented domains. Its purpose is simple – to enhance transparency and to reduce ad fraud in the programmatic advertising ecosystem. Simply, it’s a text file you add to your web property as proof of ownership and to display the sellers you’ve approved to buy your ad inventory.

How does it work?

Every publisher’s first task should be to create a crawlable document (a .txt file) and list all of the partners that have been authorized to sell their inventory using the official ID provided by them. Then upload the document at the root level of the domain as a public crawlable file, so it’s discoverable by programmatic buyers. This way, online buyers will be able to verify that the inventory is coming from an approved source by creating a filter against your list of authorized sellers. The process of selling and buying ad inventory online is clearer and easier for both parties. Ads.txt is a means towards ensuring brand safety and allowing for greater transparency with your potential programmatic partners. Check out our eBook.

What is sellers.json?

Ads.txt has been a great tool for publishers to define who is authorized to sell their advertising inventory. Yet, Ads.txt doesn’t reveal the identities of the publisher’s account IDs within their advertising platform. So, here comes seller.json. It allows the identity of the final seller of a bid request to be discovered (once they are ads.txt authorized). It allows the identities of all nodes (entities that participated in the bid request) in the SupplyChain object to be found. Also, it displays the identification of any and all participants in the selling of a bid request.

ads.txt and sellers.json In short

To put it simply, Ads.txt is a simple and flexible method that publishers, advertisers, and distributors can use to provide information about who is allowed to sell their inventory. Sellers.json is one step further from ads.txt. It’s how publishers can list their authorized reseller partners, their seller IDs, and everything they know about the legal entity who owns the business.


Everyone in the programmatic industry benefits from both ads.tx and sellers.json. The two are efficient tools to manage the relationships between publishers, advertisers, and brands in a transparent and secure way.