Hey 👋 Just shipped Yarrow — an I Ching ("Book of Changes") divination web app that uses an LLM to write the interpretation. Live: https://iching.lifefinetuning.com The flow User types a question 3 coins are tossed 6 times (the casting itself is pure logic , no AI) The resulting King Wen hexagram (1 of 64) is identified, plus any changing-line transformation An LLM steeped in the Wilhelm/Baynes tradition writes the reading Responds in whatever language you asked in (English, Chinese, etc. — handled by the model) Tech stack Next.js 16 + Tailwind 4 + TypeScript on Vercel Supabase (auth + Postgres + magic-link email via Resend) Stripe (monthly $9.99 / annual $79) DeepSeek for the AI (cheap, works well for both English and Chinese) Resend for transactional email PostHog for product analytics + Session Replay Things I think are interesting The hexagram engine is pure logic , not AI. I encode all 64 hexagrams as binary strings and look up the King Wen number.…