Model reference · open weights

csm

Available as managed deployment Audio eustlb · community Text→speech 1 variants 1k dl/mo

csm is an open-weight audio or speech model from eustlb. AxForge deploys and operates it for you on dedicated EU-owned hardware — with the licence handled where one is required.

Available as managed deployment — configured and operated for you on dedicated EU hardware, quoted per deployment.

What it is

Released byeustlb
TypeAudio & music
TaskText→speech
Parameters (lead)1.8B
Context2k tokens
Released2025-03-26
Popularity1k downloads / month
LicenceOpen weights

About

What csm is

CSM 1B

2025/03/13 - We are releasing the 1B CSM variant. Orignal code is available on GitHub: SesameAILabs/csm.

2025/05/07 - CSM is supported in Transformers 🤗

Read the full model card

CSM (Conversational Speech Model) is a speech generation model from Sesame that generates RVQ audio codes from text and audio inputs. The model architecture employs a Llama backbone and a smaller audio decoder that produces Mimi audio codes.

A fine-tuned variant of CSM powers the interactive voice demo shown in our blog post.

A hosted HuggingFace space is also available for testing audio generation.

Usage

Generate a sentence

import torch
from transformers import CsmForConditionalGeneration, AutoProcessor

model_id = "eustlb/csm-1b"
device = "cuda" if torch.cuda.is_available() else "cpu"

# load the model and the processor
processor = AutoProcessor.from_pretrained(model_id)
model = CsmForConditionalGeneration.from_pretrained(model_id, device_map=device)

# prepare the inputs
text = "[0]The past is just a story we tell ourselves." # `[0]` for speaker id 0
inputs = processor(text, add_special_tokens=True).to(device)

# another equivalent way to prepare the inputs
conversation = [
    {"role": "0", "content": [{"type": "text", "text": "The past is just a story we tell ourselves."}]},
]
inputs = processor.apply_chat_template(
    conversation,
    tokenize=True,
    return_dict=True,
).to(device)

# infer the model
audio = model.generate(**inputs, output_audio=True)
processor.save_audio(audio, "example_without_context.wav")

CSM sounds best when provided with context

import torch
from transformers import CsmForConditionalGeneration, AutoProcessor
from datasets import load_dataset, Audio

model_id = "eustlb/csm-1b"
device = "cuda" if torch.cuda.is_available() else "cpu"

# load the model and the processor
processor = AutoProcessor.from_pretrained(model_id)
model = CsmForConditionalGeneration.from_pretrained(model_id, device_map=device)

# prepare the inputs
ds = load_dataset("hf-internal-testing/dailytalk-dummy", split="train")
# ensure the audio is 24kHz
ds = ds.cast_column("audio", Audio(sampling_rate=24000))
conversation = []

# 1. context
for text, audio, speaker_id in zip(ds[:4]["text"], ds[:4]["audio"], ds[:4]["speaker_id"]):
    conversation.append(
        {
            "role": f"{speaker_id}",
            "content": [{"type": "text", "text": text}, {"type": "audio", "path": audio["array"]}],
        }
    )

# 2. text prompt
conversation.append({"role": f"{ds[4]['speaker_id']}", "content": [{"type": "text", "text": ds[4]["text"]}]})

inputs = processor.apply_chat_template(
    conversation,
    tokenize=True,
    return_dict=True,
).to(device)

# infer the model
audio = model.generate(**inputs, output_audio=True)
processor.save_audio(audio, "example_with_context.wav")

Batched Inference 📦

CSM supports batched inference:

import torch
from transformers import CsmForConditionalGeneration, AutoProcessor
from datasets import load_dataset, Audio

model_id = "eustlb/csm-1b"
device = "cuda" if torch.cuda.is_available() else "cpu"

# load the model and the processor
processor = AutoProcessor.from_pretrained(model_id)
model = CsmForConditionalGeneration.from_pretrained(model_id, device_map=device)

# prepare the inputs
ds = load_dataset("hf-internal-testing/dailytalk-dummy", split="train")
# ensure the audio is 24kHz
ds = ds.cast_column("audio", Audio(sampling_rate=24000))
# here a batch with two prompts
conversation = [
    [
        {
            "role": f"{ds[0]['speaker_id']}",
            "content": [
                {"type": "text", "text": ds[0]["text"]},
                {"type": "audio", "path": ds[0]["audio"]["array"]},
            ],
        },
        {
            "role": f"{ds[1]['speaker_id']}",
            "content": [
                {"type": "text", "text": ds[1]["text"]},
            ],
        },
    ],
    [
        {
            "role": f"{ds[0]['speaker_id']}",
            "content": [
                {"type": "text", "text": ds[0]["text"]},
            ],
        }
    ],
]
inputs = processor.apply_chat_template(
    conversation,
    tokenize=True,
    return_dict=True,
).to(device)

audio = model.generate(**inputs, output_audio=True)
processor.save_audio(audio, [f"speech_batch_idx_{i}.wav" for i in range(len(audio))])

Making The Model Go Brrr 🏎️

CSM supports full-graph compilation with CUDA graphs!

import torch
import copy
from transformers import CsmForConditionalGeneration, AutoProcessor
from datasets import load_dataset

model_id = "eustlb/csm-1b"
device = "cuda"

# set logs to ensure no recompilation and graph breaks
torch._logging.set_logs(graph_breaks=True, recompiles=True, cudagraphs=True)

# load the model and the processor
processor = AutoProcessor.from_pretrained(model_id)
model = CsmForConditionalGeneration.from_pretrained(model_id, device_map=device)

# use static cache, enabling automatically torch compile with fullgraph and reduce-overhead
model.generation_config.max_length = 250 # big enough to avoid recompilation
model.generation_config.max_new_tokens = None # would take precedence over max_length
model.generation_config.cache_implementation = "static"
model.depth_decoder.generation_config.cache_implementation = "static"

# generation kwargs
gen_kwargs = {
    "do_sample": False,
    "depth_decoder_do_sample": False,
    "temperature": 1.0,
    "depth_decoder_temperature": 1.0,
}

# Define a timing decorator
class TimerContext:
    def __init__(self, name="Execution"):
        self.name = name
        self.start_event = None
        self.end_event = None

    def __enter__(self):

From the published model card. Full card on the HuggingFace links in the sidebar.

Using it via the API

Call it like any OpenAI endpoint

Once AxForge deploys eustlb-csm for you, it answers on the OpenAI-compatible API — the same base URL and keys as every other model. (eustlb-csm below is illustrative; you get the exact model name on deployment.)

$ curl -sS https://api.axforge.ai/v1/audio/transcriptions \
  -H "Authorization: Bearer $AXFORGE_API_KEY" \
  -F model="eustlb-csm" -F file=@audio.mp3

Create an account — your API key is available in the console. 3M free tokens every 30 days with every new account.

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