The WikiTrademarks Data API is here

You can now build on our USPTO data directly. The Data API lets you search marks by text and NICE class, look up any mark by serial number, list every mark an owner holds, and run clearance knockouts that score look-alike and sound-alike marks by risk. It is billed on simple usage credits: a search page costs 1, a full clearance report costs 25, and the free tier includes 250 credits a month to try it. Create a key on your developer dashboard and read the API docs for endpoints, rate limits, and copy-paste curl examples.