An honest reading, in your language.
20 languages Free basic $7 deep No signup
What is Saju?
Saju (사주, 四柱) — literally "Four Pillars" — is the Korean tradition of reading a person's birth chart through the Heavenly Stems and Earthly Branches of their year, month, day, and hour of birth. It shares roots with Chinese BaZi (八字) but carries its own interpretive conventions, refined in Korea for centuries.
This site gives you the real thing: the actual pillars, your Day Master, the Five Elements balance, the Ten Gods, hidden stems, twelve life stages, void branches, and ten-year luck cycles — not a Western horoscope dressed up in Eastern words.
What you get
- Free basic reading — Four Pillars + Day Master + Five Elements balance + a short interpretation. Instant. No signup. Generated in your browser.
- $7 Deep Reading — Everything above, plus an LLM-generated long-form interpretation that weaves the hidden stems, twelve stages, void branches, and ten-year luck cycles into a single narrative. Delivered to your inbox.
How it works
Your birth data is computed entirely in your browser. We don't store it on our servers, don't sell it, don't share it. The only data we hold is the order record needed by our payment provider and the email address you give us at checkout — solely to deliver your reading.
Who runs this
Saju is operated by Hoonsi Kim (김시훈), an individual operator based in Seoul, Republic of Korea. Background in software engineering and product. The site is built and maintained as a one-person project — no team, no investors, no data farming.
Payment & delivery
Payments are processed by Lemon Squeezy as Merchant of Record (handling tax and compliance globally). Deep Reading delivery is automated end-to-end: order webhook → LLM generation → email delivery — typical turnaround under one minute.
Methodology
The chart computation is deterministic and reproducible, based on the open-source lunar-javascript library (v1.7.7), which encodes traditional Korean Saju conventions:
- Year pillar (년주): boundary at 立春 (Start of Spring, ~Feb 4), not the lunar new year
- Month pillar (월주): boundary at each 節 (節入) of the 24 solar terms
- Day pillar (일주): 60-갑자 cycle, 子時 (23:00–01:00) treated as the start of the next day (夜子時 = 翌日)
- Hour pillar (시주): 24h → 12지 mapping
- Hidden stems (지장간), 12 stages (12운성), void branches (공망), major luck cycles (대운), shen sha (신살): 천을귀인·도화·역마): all computed via the lunar-javascript EightChar interface
True solar time (真太陽時) longitude correction is not currently applied — the birth city field is used as reading context only. For minute-level precision (hour-pillar boundary cases), please consult a credentialed practitioner.
Sources & References
The interpretive vocabulary draws on the standard Korean and Chinese classical sources:
- 子平真詮 (Ziping Zhenquan) — format(格局) and favorable god(用神) framework
- 滴天髓 (Ditianshui) — five elements balance and Day Master strength
- 三命通會 (Sanming Tonghui) — comprehensive ten gods and shen sha catalogue
- 窮通寶鑑 (Qiongtong Baojian) — seasonal Day Master adjustments
This site does not claim to replace a credentialed practitioner; it is a software interpretation aimed at making the framework accessible globally.
AI Model Card
The long-form Deep Reading ($7) is generated by:
- Model: Anthropic Claude Haiku 4.5 (
claude-haiku-4-5-20251001) - Max output tokens: 6,144 (≈ 2,500–3,500 words)
- Reproducibility: same birth + readingType → similar interpretation (LLM is stochastic; non-zero variance)
- System prompt: src/reading-prompt.js on GitHub (MIT-licensed)
- Inputs to the model: birth date/time, gender (optional), city (optional, reading context only), language, readingType (general/career/love/wealth). Birth data is computed in-browser; only the deterministic chart structure is sent to the model; raw birth time is never stored on our servers.
The chart itself (Four Pillars, Five Elements, Ten Gods, hidden stems, 12 stages, void branches, major luck cycles, shen sha, current year pillar) is deterministic and verifiable via the open-source code. The LLM only generates the narrative interpretation layer on top.
Contact
Email: h.company.sean@gmail.com
Refund policy: /legal/refund · Terms: /legal/terms (legal pages English only)