Frontier research

#1-ranked realtime interaction models. Built on frontier AI research.

One API for speech generation, transcription, and production voice agents — fast enough for live conversation.

Try Contact sales

Play and Trust both go to team@sonacast.click. No public playground on this static site.

Live conversation · sub-90ms

Speech out44 languages

Transcribe inlive STT

Agentsproduction

Usage$0.06 / min

#1naturalness ranking

<90msspeech latency

44native languages

$0.014/min with our number

One API

Speech out. Transcribe in. Agents in production.

01 / Speech

The fastest, most natural TTS we ship. Sub-90ms. See the Speech page.

02 / Transcribe

Speech-to-text on the same API as generation. Built for turn-taking, not batch files.

03 / Agents

Prepaid agent minutes on every plan. UI-created agents are free for a limited time.

Voice agents for every industry

Illustrated floor-plan scenes from the source — realtime rooms, not a call-center overlay.

Fraud detectionReal-time outbound verification on suspicious transactions.

Customer supportListen-in rooms that stay on the same voice API.

CollectionsOutbound lines with prepaid agent minutes.

Loan assistanceGuided conversations, not a brittle IVR tree.

WealthLow-latency speech for desk and client lines.

ComplianceTrust notes on request. Same inbox.