Credit-based quota
Usage is metered in credits, allocated per billing cycle and tracked separately for TTS and ASR. Your allocation depends on your plan:
When you exhaust a cycle’s credits, requests return
402 until the cycle
resets or you upgrade.
Checking usage
Query your current usage with:402.
Rate limiting
Beyond quota, the API rate-limits bursts of requests. If you send too many too quickly you’ll get429:
Exact per-second/per-minute rate-limit thresholds depend on the deployment and
plan. Design for backoff on
429 rather than a fixed request rate.