api reference · v1
Rate limits
Updated May 12, 2026
Siftfy rate limits are enforced per API key. Free keys allow 60 requests per minute and 10,000 requests per month; Pro keys allow 600 requests per minute and include 1,000,000 requests per month. When a key exceeds its current window, the API returns 429 and includes retry guidance in the response headers.
Each API key has a per-minute and per-month cap. Cross either and the next request returns 429 with a Retry-After header.
Tier caps
| tier | per minute | per month | overage |
|---|---|---|---|
| Free | 60 | 10,000 | None — requests past the cap return 429 until the next window. |
| Pro | 600 | 1,000,000 | $0.0001 per request after the included 1M. |
See pricing for the full breakdown and how to upgrade.
Response headers
Every successful response carries the headers below so you can ramp gracefully without parsing 429s.
| header | meaning |
|---|---|
| X-RateLimit-Daily-Used | Number of requests made by this key today (UTC). |
| X-RateLimit-Daily-Cap | Daily ceiling for the current tier. |
| Retry-After | Present on 429 responses. Seconds to wait before retrying. |
Burst tolerance
The per-minute cap allows short bursts up to roughly 2× the steady-state rate before throttling kicks in. Sustained traffic above the cap will always 429 — for predictable high volume, talk to us about Pro or a dedicated tier.