HTTP status codes / 4xx — Client error
429 Too Many Requests
What it means
You are being rate limited. The Retry-After header, when present, says how long to back off.
What causes it
Polling too fast, parallel requests from one key, shared IPs hitting a common limit, scraping detection.
How to fix it
Honor Retry-After, add exponential backoff with jitter, batch requests where the API allows. Persistent 429s at low volume: your IP may share a limit with others (corporate NAT, cloud egress).