Documentation
Choosing an astrology API
What to check before you build on any astrology API, including ours: accuracy, coverage, time zones, languages, pricing and leaving.
You will live with this choice for years, so check more than the feature list. These questions work for any provider, including us.
Can you check its accuracy?
Ask for a published comparison against a reference such as JPL Horizons that you can rerun. Try three births you know well, including one with an old date and one outside India, and compare with software you trust. Ours is on the accuracy page.
Does it handle time zones for you?
Try a birth in India in 1943, when clocks were moved, and one in London near a clock change. If the API wants a numeric offset from you, you have to solve this problem yourself.
Does it cover what you will need next year?
List what you need now and what you might add. Then check the list against the endpoints themselves, not the marketing page. Can you get one chart without buying a whole bundle? Are the conventions documented?
Are the responses easy to use?
Look at a real response. Look for numbers as numbers, consistent names, and errors with machine-readable codes. Check for an OpenAPI document, SDKs in your language, and retries that cannot charge twice.
What languages are real?
Ask whether a language covers the text, or only sign and planet names. Ask whether a person has reviewed it. Ours is mostly machine-written and says so.
How does pricing behave when you grow?
Work out your cost at ten times your expected traffic. Check whether errors are charged, what happens when you run out, and what a heavy endpoint costs compared with a light one. Our calculator does this for your own mix.
Can you leave?
Good signs are a standard JSON format, no lock-in to a proprietary chart ID, and being able to export your data. Check how long results and files are kept.
Compare for yourself
Our comparison pages map other APIs' endpoints to ours, with sources and dates, including what they offer and we do not.