Yes. Sovrn uses the IAB's ads.txt crawler to validate ads.txt compliance for every domain you submit for monetization. This crawler reads the ads.txt file hosted at the root of your domain to confirm that Sovrn is listed as an authorized seller of your inventory. The crawler information you’ll want to allow-list is:
-
User Agent: "IAB-Tech-Lab"
-
IP Address:
-
Production - 34.136.234.48
-
Staging - 35.238.173.139
-
Why does Sovrn crawl your ads.txt?
Before DSPs will bid on your inventory, they verify that the seller sending them a bid request is actually authorized by the publisher. They do this by checking the ads.txt file on your domain. If Sovrn isn't listed — or if the listing contains errors — DSPs will reject those bid requests, and you'll lose revenue as a result.
Sovrn's crawler runs this same check on your behalf to make sure your domain remains eligible for monetization. Compliance is monitored on an ongoing basis, so any changes you make to your ads.txt file should be reflected within 2 business days.
What does Sovrn's crawler actually check?
The crawler fetches the file at yourdomain.com/ads.txt and verifies that the correct Sovrn entries are present and properly formatted. Specifically, it looks for lines in this format:
lijit.com, [YOUR_ACCOUNT_ID], DIRECT, fafdf38b16bf6b2b
lijit.com, [YOUR_ACCOUNT_ID]-eb, DIRECT, fafdf38b16bf6b2b
You can find your exact ads.txt lines — including your account ID — in the Sovrn Platform here.
Does my ads.txt file need to be publicly accessible?
Yes. Your ads.txt file must be accessible from all IP geolocations. If the crawler (or a DSP's crawler) can't reach the file due to geo-blocking or access restrictions, your inventory will not be eligible for monetization.
The file must be hosted at the root level of your domain — for example, https://yoursite.com/ads.txt. HTTP to HTTPS redirects on the same root domain are acceptable.
What if I'm monetizing a mobile app?
For mobile app inventory, the equivalent standard is app-ads.txt. Instead of being hosted at your app's URL (apps don't have a root domain), the file is hosted on your developer website — for example, https://yourdcompany.com/app-ads.txt. Sovrn's crawler follows the same IAB-standard process: it retrieves your developer website URL from the app store listing, then fetches your app-ads.txt from that domain.
App-ads.txt compliance is also monitored continuously.
What happens if I'm not compliant?
If Sovrn's crawler can't validate your ads.txt entries — because the file is missing, inaccessible, or contains incorrect lines — your domain or app may be flagged or denied for monetization. Make sure your file matches exactly what's shown in the Sovrn Platform, and avoid formatting issues like using www. before the domain name in your entry lines.
Questions? Concerns? Our team would be more than happy to help. Reach out to our Support Team here.