TTS API billing: why QA-gated metering matters for pipelines — Audra

Most TTS APIs meter every request — including silent failures, truncated audio, and retry storms. Audra reserves credits when a render starts, then finalizes only after automated QA passes. Failed gates auto-refund to your balance.

Reserve → render → QA → finalize

POST /v2/speech trims input, reserves billable characters, runs inference + mastering, then checks duration and silence gaps. Credits finalize on pass; otherwise the reservation refunds. Check X-QA-Passed on responses during integration testing.

Why pipelines care

• Nightly cron retries do not drain credits on bad chunks
• Course platforms avoid billing students for broken lesson audio
• Podcast workers can fail loud on QA instead of shipping silence
• Idempotency keys prevent double-billing duplicate POSTs

What QA does not cover

QA validates technical output (duration, silence) — not subjective voice fit or pronunciation taste. Use /dashboard/playground and /voices previews before production cutover. Phonetics tooling on Essential helps finance and medical terms.

Refund policy details at /refund. Pricing and commercial unlock at /pricing. More billing FAQs at /faq. Live stats and savings methodology on /proof.