Rate limits
Two independent limits apply per API key, never per account.
Requests per second: each key has its own budget (10 rps by default), checked on every request. A key with a higher-volume need can have this raised on request.
Requests per month: each key also has a monthly cap (100,000 by default), reset on the first of each UTC month.
Exceeding either limit returns 429 Too Many Requests with a Retry-After header. A key with multiple integrations sharing it will share its budget too — separate keys per integration if that matters to you.