Rate limits

Limits are applied per API key and reset on a rolling 60-second window.

ENDPOINT TYPE	SANDBOX	GROWTH	ENTERPRISE
TTS (characters / min)	5,000	100,000	Custom
Audio Processing (min / hr)	10	500	Custom
Agent Concurrent Sessions	5	100	Custom

When you exceed a rate limit, the API returns 429 Too Many Requests with a Retry-After header. Enterprise plans include dedicated capacity with guaranteed throughput SLAs.