Credits & Pricing

Every API request consumes credits. Your account has two balances — free credits (500/month, reset automatically) and paid credits (purchased, never expire).

Free credits are used first. When they run out, paid credits are consumed. If both are exhausted, requests return 402 Payment Required.

Credit costs by endpoint

Why do some endpoints cost more?

Position lookup endpoints compute planetary coordinates for a single moment in time. They resolve in under a millisecond — it's a direct calculation with a known answer.

Iterative search endpoints are fundamentally different. Instead of "where is Mars right now?", they answer questions like "when is the next solar eclipse?" or "when does the Sun enter Aries?". These require the engine to step through time, testing candidate moments until it converges on the answer. Some specifics:

• Eclipse search scans the lunar or solar cycle looking for alignment geometry, then refines contact times and magnitudes. Solar eclipses are the most expensive because local calculations require computing the Moon's shadow path across Earth's surface.
• Heliacal events use the Schaefer sky brightness model to determine when a planet becomes visible against the twilight sky — a calculation that depends on atmospheric conditions, observer acuity, and the relative geometry of the Sun, horizon, and target body.
• Ingress search iterates through a planet's orbit to find the exact moment it crosses a target ecliptic longitude.

Chart computation endpoints compute positions and then layer on additional analysis — aspects, dignities, house placements, retrograde detection, and out-of-bounds status. A natal chart (2 credits) does significantly more work than a raw position lookup.

Relationship charts are the most expensive because they compute two full charts and then perform inter-chart analysis. Synastry computes aspects between every body in chart A and every body in chart B. Composite and Davison charts each require two sets of positions before computing the relationship chart.

Derived charts (progressed, draconic) transform a natal chart through additional computation — progressions calculate an adjusted datetime, draconic charts rotate all positions to align the North Node with 0° Aries.

The credit costs reflect this computational difference. A search that returns multiple results (e.g., count=5) still costs the same — you're charged per request, not per result.

Free tier

Every account gets 500 free credits per month, reset on the 1st. No credit card required.

At 1 credit per position request, that's 500 chart calculations — enough for prototyping, personal projects, or low-volume production use.

Purchasing credits

Buy credits in your dashboard. Credits are prepaid at $0.01 per credit (1 cent per request for standard endpoints). Purchased credits never expire.

Checking your balance

Every API response includes your remaining balance in the meta object:

{
  "meta": {
    "credits_used": 1,
    "credits_remaining": 499
  }
}

You can also check your balance in the dashboard.