It uses Claude's Vision API to read facial expressions, body language, styling choices, and overall energy from the photo. The difference from typical face-rating apps is that it focuses on personality and vibe rather than bone structure or symmetry (though it does golden ratio and face shape analysis too). The AI analyzes things like approachability, confidence level, conversation style, and what kind of first impression you make.
Technical details: Rails 8, Hotwire/Turbo for real-time result streaming, PostgreSQL with JSONB for flexible AI output storage, Solid Queue for background jobs. Two Claude API calls run in parallel (core scores on Sonnet, detail analysis on Haiku) and results are broadcast via Turbo Streams as they complete, so you see your score within 8-12 seconds rather than waiting 20+ seconds for everything.
Freemium model: basic score and 2/5 category scores are free, full results are $1.99-$2.49. Over 6,000 scans analyzed so far.
Built as a solo project. No auth required -- cookie-based session identity, no signup friction.
Free to try: https://firstvibe.app
Open to feedback, especially on the AI analysis quality and the free/paid split. Would love to hear what you think.