Understanding and Using Sellers.json

What is Sellers.json?

Sellers.json is an industry-standard file format defined by the IAB Tech Lab that allows buyers to identify sellers of digital ad inventory, whether they are direct sellers or intermediaries, within the programmatic advertising supply chain. It enhances transparency, reduces fraud, and fosters trust between buyers and sellers.

The file includes information about entities (e.g., publishers, resellers) authorized to sell ad inventory, providing buyers with a way to verify the authenticity of sellers.

Key Terms in Sellers.json

• seller_id: This ID matches the one in the ads.txt file and the SupplyChain.nodes array's sid property. It typically appears in the Publisher.Id property of an OpenRTB request.
• seller_type: Indicates whether the entity is a publisher (PUBLISHER), reseller (INTERMEDIARY) or both (BOTH):
• Publisher indicates that the inventory sold through this account is owned by the named entity and the advertising system pays them directly. 
• Intermediary indicates that the inventory sold through this account is not owned by the named entity or the advertising system does not pay them directly. 
• Both indicates that both types of inventory are transacted by this seller.
• domain: The business domain name of the company paid for inventory under the given seller_id. Required if is_confidential=0 and the seller has a web presence. For INTERMEDIARY or BOTH seller_type the root domain of the seller's Sellers.json file is used. Can be omitted if is_confidential=1 or no web presence exists.
• is_confidential: Indicates the confidentiality of the seller's identity, with 0 meaning non-confidential and 1 meaning confidential. If confidential, the object will not include a name and domain.

How Sellers.json Works in the RTB-Stack Platform

In the RTB-Stack platform, a sellers.json file is automatically generated for each client based on their SSP settings. This file is kept up-to-date with any changes, ensuring accuracy and consistency in supply chain representation.

Accessing the Sellers.json File

1. Navigate to the Inventory -> SSPs.
2. Click the Sellers.json button located in the upper right corner.
   
3. In the window that opens, find the Sellers.json URL field.
4. Copy the provided URL or click on it to open the sellers.json file in your browser.

Example of a File Structure

{
  "sellers": [
    {
      "seller_id": "12345",
      "name": "Example Publisher",
      "domain": "example.com",
      "seller_type": "PUBLISHER"
    },
    {
      "seller_id": "67890",
      "name": "Example Reseller",
      "domain": "reseller.com",
      "seller_type": "RESELLER"
    },
   {
      "seller_id": "54321",
      "seller_type": "PUBLISHER",
      "is_confidential": 1
   }   
  ]
}
           

Setting Up Your Sellers.json

If you don't have your own sellers.json file, you have two options:

1. Use the Platform's File: The RTB-Stack platform automatically manages the sellers.json file for you. Ensure all SSP information is correctly entered in the settings, and the platform will handle the rest.
2. Host Our File on Your Domain: You can call and display our platform's sellers.json on your root domain. Ensure all SSP information is correctly entered in the settings to keep the file up-to-date. Follow these guidelines for this setup:
• Accessibility: Ensure the file is publicly accessible and complies with the IAB Tech Lab specifications.
• Domain Location: Host the file on the root domain. The root domain is defined as the public suffix plus one string in the name. For example, in the domain "example.com," "com" is the public suffix, and "example" is the one string in the name. Together, they form the root domain "example.com". Make sure the final sellers.json URL matches your business domain.
• Access Path: The file must be accessible via HTTP/HTTPS at the standard path "/sellers.json" (e.g., https://example.com/sellers.json) with the "Content-Type: application/json" header. HTTPS is preferred for secure access.
• Redirects: Redirects are allowed within the original root domain. A single redirect to a third-party domain is allowed for delegation, but further redirects from the third-party domain are treated as errors. In practice, such redirects may not be processed, so it's better to avoid them.
  

If you manage your own sellers.json, make sure to enter the Custom Publisher ID in the SSP settings. Otherwise, the data in the Schain object and the sellers.json will differ, which is invalid.

For more information, visit the IAB Tech Lab Sellers.json Documentation.