Twelve hours is short enough that the safe idea and the ambitious one cost about the same, so we'd love to see the ambitious one. We're looking for genuinely creative, out-of-the-box projects: the idea that's been sitting in your notes app, the use case nobody has tried yet, the demo that makes a judge stop and ask how you did it. If your one-line pitch sounds like something that already exists, there's probably a more interesting version of it.

Include a project name and short description, a working demo you'll present live, a repo link, your full team roster, and non-trivial use of Grok models or the xAI API. If it doesn't call our models, it doesn't get judged. A demo video under three minutes on YouTube or Vimeo is optional but recommended.

Going for Most Users: include your live URL and user count, and be ready to show a judge the analytics.

Two criteria. Usefulness: would a real person want this tomorrow, or is it a slide? Technical complexity: show us the part that was hard.