Hi. I'm the developer behind Cheonmyeongdang (천명당) — an AI-powered Korean Saju engine that I'm building from a small studio in Gyeongju, the 1,000-year-old former capital of Korea. No team. No VC. Just me, an API key, and a lot of classical Saju textbooks.
Updated manually each month. Nothing fancy here yet — that's the point. If you're watching an indie project from day zero, you're seeing the truth, not a polished pitch deck.
Saju (사주팔자, Four Pillars of Destiny) is a 1,000-year-old Korean system that maps your birth moment to 8 stem-branch pillars. It is, in my opinion, the most rigorous fortune-telling framework that ever existed — closer to mathematics than to mysticism.
But the global audience can't access it. Western astrology has Co-Star and The Pattern. Bazi (the Chinese cousin) has a few apps. Saju? Almost nothing in English. The few that exist are either pure ChatGPT wrappers (which hallucinate your hour pillar 30% of the time) or Korean-only services that won't accept a foreign credit card.
The bet: Korean traditional wisdom + a deterministic 8-pillar engine + Claude AI for interpretation + 4-language UI + PayPal global checkout. Make 1,000 years of Korean knowledge readable by anyone in the world with a birth date.
The 8-pillar calculation is done by classical algorithms, validated against printed Korean reference charts. Claude AI only handles the interpretation layer — exactly how a human Korean reader would explain your chart in plain language.
Full Saju calculation, daily fortune, and one Claude Q&A round are free forever. Premium ($7.50 one-time or $4.99/mo) unlocks unlimited Q&A, monthly fortune, compatibility, and a 30-page PDF report.
Every page is rewritten natively in 4 languages — not machine-translated. The English version is not a translation of the Korean; the Japanese version is not a translation of the English. Each has its own copy, examples, and cultural framing.
You don't lose anything by trying us. Cancel anytime, refund anytime, on any premium reading within 24 hours.
Cheonmyeongdang is the first SaaS product under KunStudio, a one-person studio I started in 2026 in Gyeongju. The thesis is simple: take traditions that are deeply Korean — Saju, Korean tax law, Korean travel knowledge, Korean wisdom — and rebuild them as global SaaS with AI as the interpreter layer.
Western astrology uses 12 sun signs. Saju uses 60 stem-branch pairs across 4 pillars, which means 12,960,000 possible birth-time combinations. That's roughly 60× more granularity than your zodiac sun sign.
It's not magic. It's a 1,000-year-old taxonomy of human archetypes, refined by Korean scholars who treated it as a serious discipline. AI can finally make it accessible without losing the rigor.
I share lessons, mistakes, and revenue numbers as openly as I reasonably can. If you want to follow along — or if you have a question about indie SaaS, Korean traditional knowledge, or AI-augmented domain products — the contact email is below.