Sesame CSM-1B
1B conversational speech model that conditions on prior dialogue context. Apache-2.0, in Hugging Face Transformers since 4.52.1. Not a low-latency streaming engine out of the box.
Overview
Best for: Research into context-aware conversational speech.
At a glance
No official streaming path. Gated download.
Text plus optional conversation context (text + audio segments)
24 kHz waveform (generator.sample_rate)
English (other languages weak, per README)
Speaker IDs and context-based voice continuation
No streaming or latency claim in the README.
Wherever you deploy it
Your own deployment; no vendor data processing
CUDA GPU recommended.
Apache-2.0
Features
- context-conditioned conversational prosody
- Transformers integration
Pricing
| What | Price | Unit |
|---|---|---|
| Weights | $0 |
Self-hosted: cost is your GPU/CPU time, not per character
Free tier: Open weights
Source: huggingface.co
Setup
- git clone https://github.com/SesameAILabs/csm and install requirements (CUDA GPU).
- Accept the gated model on Hugging Face.
- Call load_csm_1b and generate.
Endpoint
LocalAuthentication
Hugging Face token
Quick start python
# from the SesameAILabs/csm repo (run inside the cloned repo)
import torchaudio
from generator import load_csm_1b
generator = load_csm_1b(device="cuda")
audio = generator.generate(text="Hello from Sesame.", speaker=0, context=[],
max_audio_length_ms=10_000)
torchaudio.save("audio.wav", audio.unsqueeze(0).cpu(), generator.sample_rate)Written from the current docs. Check the vendor's SDK version before you ship.
Warnings
The open model is not the demo
The public 1B checkpoint is a base generation model; it does not reproduce Sesame's hosted conversational demo out of the box.
Not built for streaming agents
No official streaming path; latency is high compared with purpose-built realtime TTS.
Gated download
Requires accepting terms on Hugging Face before download.
Plus 3 warnings that apply to all open models APIs. See category warnings.
Limits
- No official streaming
- English focus
Models and products
| Name | Status |
|---|---|
| sesame/csm-1b | Released 2025-03 (gated, auto-approval) |
Docs and sources
Docs
Sources used
Hardware minimums.