Rate Limits
Your plan sets a monthly request quota; when it is exhausted you get 429. This page documents plan tiers, the response headers that expose limits, overage pricing, webhook slot limits, and the Historical ADS-B path tiers that control retention windows.
Quota is enforced in different places on the two channels —
For retry behaviour on 429, see Error Handling → Retry rules. For subscribing or applying for a trial, see Getting Started.
Plans
The FREE Trial is not self-serve — apply at skylinkapi.com/apply. Paid plans (Basic and above) are available at our checkout or on the RapidAPI listing.
| Plan | Price | Requests/month | Overage | Webhooks | Historical ADS-B (max window per request) |
|---|---|---|---|---|---|
| FREE Trial | Free | 1,000 | $0.007/req | — | — |
| Basic | $18.59/mo | 5,000 | $0.007/req | — | — |
| Pro | $45.35/mo | 20,000 | $0.001/req | 1 | 90 days — /ultra/history/... only |
| Ultra | $105.59/mo | 70,000 | $0.001/req | 3 | 90 days on /ultra/... or 365 days on /mega/... |
| Mega | $205.39/mo | 200,000 | $0.001/req | 10 | 90 days on /ultra/... or 365 days on /mega/... |
Per-request lookback for Historical ADS-B (archived aircraft position data going back up to 365 days) is enforced by the URL path prefix, not the plan name alone. Use /ultra/history/... for windows up to 90 days and /mega/history/... for up to 365 days (Ultra and Mega only). See Historical ADS-B path tiers below.
Upgrade, cancel or check usage from your Polar customer portal.
Quota headers
Every successful response includes these headers:
| Header | Meaning |
|---|---|
X-RateLimit-Requests-Limit | Request ceiling for the current window |
X-RateLimit-Requests-Remaining | Requests left in that window |
X-RateLimit-Requests-Reset | Seconds until the window resets |
These headers report the anti-abuse ceiling, not your monthly plan quota. The ceiling is a hard per-day limit set well above normal usage, there to bound the damage from a compromised or runaway key. Do not use these headers to work out remaining paid quota or your bill — check your Polar customer portal for usage against your plan.
Requests that reach the API and authenticate count toward your allowance, including ones that error because of your input (for example 404 or 422). Requests rejected for a missing or invalid key are not counted.
429 — Rate limit exceeded
When the limit is hit you get:
{ "message": "Too many requests" }Back off exponentially and retry. See Error Handling → Retry rules for the full retry table and a Python helper.
Historical ADS-B path tiers
Historical ADS-B endpoints use URL path prefixes that map to retention windows — these prefixes are not RapidAPI plan names:
| URL path prefix | Available on | Max window per request |
|---|---|---|
/ultra/history/... | Pro, Ultra, Mega | 90 days (server-enforced) |
/mega/history/... | Ultra, Mega | 365 days |
Ultra and Mega subscribers may call either prefix. Use /ultra/history/... for recent windows (≤90 days) and /mega/history/... when you need longer lookback or higher per-request limits. Pro subscribers are limited to /ultra/history/... only.
Important: Choosing the wrong prefix for your plan or date range returns gateway 401/403 or validation 422 — not a quota 429. Plan-gate errors are documented on the Historical ADS-B hub.
See Historical ADS-B for endpoint details and integration examples.