Credits, rate limits & errors

Prices are on the pricing page; this page is the full fine print. Limits are enforced at the API gateway, per account: all your keys and your Explorer session share one credit balance.

Credits

Elevation calls and downloads are paid for in credits:

• Every account gets 10,000 free credits a month. They reset at the start of each calendar month (UTC), don't roll over, and are spent first.
• Purchased credits never expire. Packs start at $10 for 100,000 credits; bigger packs carry bonus credits. Buy them from your dashboard.
• Your first purchase also unlocks full-size raster extracts, 512-point batches, Darly-hosted COG downloads, and higher burst limits.
• Data out is rounded up per request: a raster response always costs at least 1 credit. Downloads are charged at full file size.
• Credits are charged only on successful (2xx) responses. Errors and rate-limited calls are never charged.
• When you run out, the API returns 402 until you buy more or your free credits reset. There are no overage bills.
• A batch is all or nothing: if its points cost more than you have left, the whole request returns 402, so split it or buy credits.
• A raster extract's size is only known once it is built, so an extract starts as long as you have any credits left and is charged in full; your balance can end slightly below zero. That shortfall is forgiven when the free credits reset, or comes out of your next purchase if you buy credits before then. While an extract runs, its maximum size is held against your balance, so parallel extracts need credits for each.
• Refunds: unused purchased credits can be refunded within 14 days of purchase; write to [email protected]. See the terms for details.
• Need volume pricing or invoicing? [email protected].

Per-minute burst limits

Elevation points/min is point-weighted like credits: one 512-point batch consumes 512 units of the 12,000/min budget. Burst capacity is reserved before a request is processed, so requests that finish with a 4xx or 5xx still consume per-minute capacity (they never cost credits). A request rejected by the burst limiter does not consume additional capacity; wait until X-RateLimit-Reset before retrying.

STAC requests/min is page-weighted: /search and /collections/{id}/items calls consume one unit per 10 items requested (a limit=100 page costs 10 units; everything else, including metadata routes, costs 1). Small pages and narrow filters stretch your budget further than crawling at limit=100.

Rate-limit headers

Every response carries the state of the limiter that applied to it:

X-RateLimit-Limit: 300
X-RateLimit-Remaining: 297
X-RateLimit-Reset: 1783041000

X-RateLimit-Reset is a Unix timestamp (seconds). On 429, wait until the reset before retrying; a simple sleep-until-reset loop is more effective than exponential backoff here, because windows are fixed, not sliding.

Error reference

Key off the HTTP status code (and X-RateLimit-* headers), not the body text.

An invalid or revoked key is not an error on STAC routes; it falls back to anonymous access silently. See authentication.

Playing nice

• Batch point lookups into points calls instead of many point calls: same credit cost, far fewer requests against the per-minute window.
• Cache responses on your side. A value for a fixed location only changes when new data lands for it (a newer acquisition or a finer collection wins the source ranking), so cache freely and record the collection from the response to know what a cached value came from.
• Use bbox/datetime filters and reasonable limits on STAC search instead of paginating the world.