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Astral API Docs

Credits & metering

Usage is metered in credits. Every successful response tells you exactly what it cost, in the response itself:

{
  "data": { "positions": [ /* ... */ ] },
  "meta": {
    "calc_version": "0.1.0",
    "settings_resolved": { /* ... */ },
    "subject_resolved": { /* ... */ },
    "credits_charged": 1
  }
}

meta.credits_charged is present on every success response, without exception. This is deliberate. The standing complaint against metered calculation APIs is credit-burn opacity: you find out what a month of traffic cost from a dashboard, after the fact, with no way to reconcile the number against your own request logs. We refuse to replicate that. With the charge reported in-band, your own logs are the audit trail — sum credits_charged and you have your bill’s usage line, computed independently of ours.

Current prices

Section titled “Current prices”
Endpoint Credits
POST /v1/western/positions 1
GET /health Free, unmetered
GET /ready Free, unmetered

Verify it yourself — this call charges exactly one credit and says so:

Terminal window
curl -s https://astral-external-api-iksoi6t3nq-ue.a.run.app/v1/western/positions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "subject": {
      "datetime": "1992-11-22T08:45:00+05:30",
      "location": { "latitude": 28.6139, "longitude": 77.209 }
    }
  }' | jq .

(Assumes API_KEY is exported — see Authentication.)

Errors are never charged

Section titled “Errors are never charged”

A 4xx or 5xx response charges zero credits. A request rejected for validation, a 401, a malformed body, a bug on our side, a shed-load 503 — none of them meter. You pay for answers, not attempts. This also means retrying a 503 costs nothing until the retry actually succeeds.

Error responses are problem documents and carry no meta envelope at all, so there is no credits_charged field to misread as a charge.

Planned pricing

Section titled “Planned pricing”

Rate limiting

Section titled “Rate limiting”

API spec v0.1.0 · docs 0e4f5ec