Sesame CSM-1B (Conversational Speech Model)
Open base generation model only (no fine-tuned voices, English-centric, cannot generate text itself); the Maya/Miles demo voices use Sesame's larger in-house models. Native in Transformers since v4.52.1. Sesame raised a $250M Series B (Oct 2025, Sequoia/Spark) and launched a public-preview iOS app with four agents (Maya, Miles, Simone, Charlie) in 39 countries on 2026-05-28; smart glasses targeted for 2027. No newer open Sesame model found as of 2026-09-29.
- Input
- text, audio
- Output
- audio
- License
- apache-2.0
- Verified
- 2026-09-29
How to call it
| Provider | Model id | Endpoint / URL | Docs |
|---|---|---|---|
| Hugging Face | sesame/csm-1b | huggingface.co/sesame/csm-1b | — |
| Transformers | sesame/csm-1b | — | docs |
| Sesame app (Maya, Miles, Simone, Charlie — hosted larger models) | — | www.sesame.com/ | — |
Notable capabilities (1)
- Context-conditioned conversational TTS: Llama backbone + audio decoder emitting Mimi audio codes; generates speech conditioned on prior conversation audio/text so prosody fits the dialogue; voice prompting via context segments. source
Sources: https://huggingface.co/sesame/csm-1b , https://techcrunch.com/2026/05/28/sesame-the-conversational-ai-startup-from-oculus-founders-launches-its-ios-app/
Timeline entry
- Sesame launches its voice-companion iOS app (Maya, Miles, Simone, Charlie) in public preview ★★★
Sesame, the Oculus co-founders' conversational-voice startup behind the viral Maya/Miles demo and the open CSM-1B model, released a free public-preview iOS app on 2026-05-28 in 39 countries. It has four voice agents (Maya, Miles, Simone, Charlie), each with its own personality and memory. An…