All questions are graded by GPT, an AI created by OpenAI. The actual test is an oral test graded by a USCIS officer. You'll be asked 10 of 100 of these questions and you'll need to get 6 of them right to pass. You can find the full list of questions and rules here.
I work on AI in San Francisco, the city of progress. This website is open source on Github. If you find a bug, please send me a DM on Twitter: @evanjconrad.