What does ads.txt validator check for?

ads.txt validator checks the content of an ads.txt file to ensure it follows the IAB (Interactive Advertising Bureau) standards and guidelines correctly. Here are some of the main things an ads.txt validator checks for:

• Syntax and Formatting: The validator checks if the ads.txt file is formatted correctly, including the use of tabs, spaces, and correct delimiters (e.g., commas) between fields.
• Valid Domain Names: It verifies that the domain names listed in the file are valid and properly formatted.
• Publisher Accounts: The validator checks if the publisher accounts (i.e., the "Publisher ID") listed in the file are correctly formatted and match the authorized seller's account IDs.
• Authorized Sellers: It checks if the authorized sellers (i.e., the "Seller Account ID") listed in the file are correctly formatted and match the IDs of legitimate advertising platforms and exchanges.
• Valid "direct" and "reseller" Values: The validator checks that the "direct" and "reseller" fields are correctly specified for each entry. "Direct" should be used for authorized sellers who have a direct relationship with the publisher, while "reseller" is used for intermediaries.
• Multiple Entries: It ensures that there are no duplicate entries for the same domain, publisher, and seller combination.
• Comments: Comments and explanatory notes (lines starting with "#" or "//") are allowed in the ads.txt file but should not cause validation errors.
• Case Sensitivity: The validator may check for case sensitivity in the field values (e.g., domain names) if necessary.
• File Encoding: It may check the file encoding to ensure it's consistent with the IAB standards.
• Overall Compliance: The validator checks if the ads.txt file adheres to the overall IAB ads.txt specification.

The purpose of an ads.txt validator is to help publishers and advertising platforms ensure that their ads.txt files are correctly configured to prevent fraudulent or unauthorized inventory sales and to maintain transparency in the digital advertising ecosystem. Properly configured ads.txt files help protect both publishers and advertisers by specifying authorized sellers and preventing ad fraud.