French AI Firm Mistral Releases Voxtral 3: Real-Time Voice Agent SDK with 50+ Language Support and Multi-Step Tool Calling

French artificial intelligence company Mistral AI released Voxtral 3 on October 20, 2026. This product family includes cutting-edge speech-to-text (STT) and text-to-speech (TTS) models, along with a new voice agent SDK designed to address the primary challenges in building end-to-end voice agents: enabling systems to simultaneously listen accurately, reason deeply, speak naturally, and execute multi-step operations across connected systems.

The core innovation of Voxtral 3 lies in its voice agent SDK, which combines listening, thinking, tool calling, and speaking into a single real-time streaming pipeline. This allows agents built with the SDK not just to converse, but to retrieve information, interact with enterprise internal systems, and complete specific tasks during live calls. For instance, in a demonstration scenario, an agent can identify content from a French referral letter, automatically query appointment slots, book the appointment, and then confirm details with the user in English.

Regarding model performance, Mistral claims that Voxtral Small Transcribe 3 achieves state-of-the-art results in multilingual transcription, diarization, and context-biasing, supporting over 50 languages including 24 official EU languages and many low-resource Asian and Indic languages. Vendor self-test data indicates it outperforms Whisper, Scribe v2 and Gemini 3.5 Transcribe in Word Error Rate (WER) on the FLEURS benchmark. Additionally, Voxtral Mini TTS 3 introduces new voices capable of adjusting emotion, pace, and emphasis based on conversational context, supporting over 35 languages and 50+ dialects.