#compatibility

Biorhythm calculation as an API, computed locally and deterministically — a fun, for-entertainment model of three sine-wave cycles that supposedly run from the day you are born: a 23-day physical cycle, a 28-day emotional cycle and a 33-day intellectual cycle, each given by sin(2π·days/period). The cycles endpoint computes the three percentages and their phase (rising, falling or a critical zero-crossing where the cycle changes sign) for a given date, plus the average. The range endpoint returns the daily values over a window of up to 60 days from a start date, ready to plot as three sine waves. The compatibility endpoint compares two birthdates and gives, for each cycle, a defined heuristic compatibility score (1 + cos(2π·Δdays/period))/2 — 100 % when two people's cycles are perfectly in phase and 0 % when exactly opposite — and an overall score. Dates are in YYYY-MM-DD form. Biorhythms have no scientific basis; this is purely an entertainment tool. Everything is computed locally and deterministically, so it is instant and private. Ideal for lifestyle, horoscope, wellness, game and novelty app developers, daily-widget and compatibility tools, and fun dashboards. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the entertainment biorhythm; for name and birthdate numerology use a numerology API and for star signs a zodiac API.

api.oanor.com/biorhythm-api

Blood-type compatibility as an API, covering the ABO and Rh(D) systems, computed locally and deterministically. The compatibility endpoint says whether a given donor can give to a given recipient, for both red blood cells and plasma — the red-cell rule being that the donor's antigens must be a subset of the recipient's (Rh included), and plasma being the reverse and ignoring Rh. The info endpoint describes a blood type: the antigens it carries, the antibodies in its plasma, every type it can receive red cells from and donate red cells to, who it can give plasma to, whether it is a universal red-cell donor (O−), universal red-cell recipient (AB+) or universal plasma donor (AB), and its approximate US population frequency. The donors endpoint lists every compatible donor type for a recipient, for red cells or plasma. Blood types are accepted in many forms (O-, O neg, AB positive, …). Everything is computed locally and deterministically, so it is instant and private. This is educational only — real transfusion requires laboratory cross-matching and clinical judgement, and it is not medical advice. Ideal for medical-education and first-aid apps, blood-donation and health tools, and quiz and reference sites. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is ABO/Rh compatibility; for a drug reference database use a drug API.

api.oanor.com/bloodtype-api