Mistral's Voxtral 3 is a full voice-agent stack from $0.0035/min
Four speech models and a LiveKit-based SDK wire transcription, reasoning and TTS into one sub-second pipeline — 50+ languages, SIP telephony, API-first.
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One SDK for the whole voice loop
The voice-agent SDK, built on LiveKit, chains realtime transcription, end-of-turn detection, reasoning with tool calls, and TTS into a single streaming pipeline, with function calling, web search, and SIP/WebRTC telephony. Full agent turns land under one second and the agent stops when the caller interrupts — enough to ship a phone-callable agent without gluing five vendors together.
Transcription from $0.0035 a minute
Three speech-to-text models: Mini Transcribe 3 at $0.0035/min (fast batch), Small Transcribe 3 at $0.0040/min (50+ languages including all 24 official EU languages), and Mini Transcribe Realtime 3 at $0.008/min with sub-500ms streaming. That is roughly 21 to 48 cents per hour of audio — cheap enough to transcribe everything by default.
Speech 3 TTS at $13 per million characters
The TTS model handles batch and realtime synthesis over one API across 35+ languages and 50+ dialects, with voice presets for 18 languages. At $13 per 1M characters, a 500-character spoken reply runs about $0.0065, so you can price your agent's talk time precisely.
It claims to crush Whisper large-v3
Mistral reports Small Transcribe 3 at ~4.0% word-error-rate on FLEURS 45 versus Whisper large-v3's ~14.9%, plus diarization and keyphrase wins over Gemini 3.5 Transcribe and Scribe v2; context biasing lifts keyphrase recall from 81.4% to 94.6%. The numbers are vendor-reported and unverified, but a 3-4x WER gap is worth a bake-off against your current STT.
API-first, swappable stages — but check the license
Each stage is a separate model you can swap, so you can change the LLM, voice, or language without rewriting the agent. Mistral points to self-deployment and on-prem via sales but did not publish open weights or a license at launch — and its earlier Voxtral TTS shipped noncommercial (CC BY-NC), so confirm terms before building a product on it.