People are already asking ChatGPT for saju readings by pasting a prompt. The prose comes out fine; the chart underneath is usually wrong, because a language model is guessing at an almanac. This connector gives your assistant the actual calculation instead.
It is a remote MCP server. Free, no API key, no account, no personal data stored — birth details are computed in the request and not written anywhere.
https://www.ioreum.com/api/mcpAdd it as a custom connector (ChatGPT → Settings → Connectors, or Claude → Settings → Connectors) and paste that URL. It speaks Streamable HTTP and needs no authentication.
calculate_sajuThe four pillars from a birth date, optional time, timezone and longitude — plus the Day Master, the Five-Element counts and the 60-gapja day character.
luck_pillarsThe ten-year luck pillars (대운 daeun / 大運 da yun): direction, starting age, and eight pillars with the age each opens. The day count behind the starting age is returned so you can check it.
check_zodiac_yearWhich zodiac animal a birth date really belongs to — reckoned from ipchun (立春, around 4 February), not 1 January and not Lunar New Year. January births are routinely mislabelled by a whole animal.
day_master_characterAny of the sixty day pillars as a reference: colour-and-animal name, a one-line epithet, and the Day Master element with its traditional nature image.
Three boundaries are where most tools quietly go wrong, and all three are handled here: the solar-term (jeolgi) change that moves the year and month pillars to the minute; true solar time, so a birth in New York is corrected by longitude and the equation of time rather than read off the wall clock; and the late-night hour convention, where the day pillar turns at 23:00 rather than midnight. Every one of these is locked by golden tests. The methodology page walks through a full worked chart.
It returns calculated facts, not a reading. There is no written interpretation, no compatibility score and no useful-god (yongsin) analysis in these tools — that is the interpretive layer, and it is the paid product. And a claim we refuse to make anywhere: no chart decides your life. Treat all of it as reference and entertainment.
Or just read your own chart
Pillars, Day Master, element balance — free, no account.
Draw my chart — free