hf-serve 0.1.2

Experimental Hugging Face API for Transformers, Diffusers and Sentence Transformers, written in Python.

hf-serve

[!WARNING] This project is still experimental, meant to replace the former huggingface-inference-toolkit.

Installation

First you need to setup your environment with uv (or with your preferred Python environment manager).

uv venv --python 3.12
source .venv/bin/activate

[!NOTE] Due to the need of --preview-features extra-build-dependencies to install flash-attn with uv without compiling it, but rather relying on the pre-built binaries, you need to use uv v0.8.13 (or higher, but beware on major updates since the feature is still experimental, so < v0.9.0 is recommended until stable).

Reference: https://docs.astral.sh/uv/concepts/projects/config/#augmenting-build-dependencies

To update uv once installed if uv version is lower than v0.8.13, simply uv self update.

Install it from the uv.lock file for CPU / MPS as follows:

uv sync --active --frozen --extra cpu

Alternatively, install it on NVIDIA CUDA 12.6 as follows:

uv sync --active --frozen --extra cuda --extra flash-attn --preview-features extra-build-dependencies

Or if you're on CUDA 12.8 then:

uv sync --active --frozen --extra cuda-128 --extra flash-attn --preview-features extra-build-dependencies

[!NOTE] There's no cuda-130 (CUDA 13.0) extra for now, as flash-attn==2.8.3's wheel-detection logic predates CUDA 13 and would silently install a mismatched cu12 wheel that fails at import time. It'll be added back once upstream fixes this.

[!WARNING] The default registry for the NVIDIA CUDA wheels for PyTorch is set to CUDA 12.6. If you want to install another PyTorch version as per the CUDA compatibility, then run e.g. uv pip install -e . --torch-backend cu128, but note it won't be relying on the uv.lock so some dependencies might mismatch.

Reference: https://docs.astral.sh/uv/guides/integration/pytorch/#automatic-backend-selection

$ uv run hf-serve --help

Examples

[!NOTE] On the examples below, given the recently introduced extra-build-dependencies for flash-attn on CUDA as per https://docs.astral.sh/uv/concepts/projects/config/#build-isolation, it means that you'll need to run the examples as uv run --preview-features extra-build-dependencies ... to disable the warning:

warning: The `extra-build-dependencies` option is experimental and may change without warning. Pass `--preview-features extra-build-dependencies` to disable this warning.

🤏 Run HuggingFaceTB/SmolLM3-3B with an OpenAI API

uv run hf-serve --model-id HuggingFaceTB/SmolLM3-3B --task text-generation --dtype float16

[!NOTE] If you are running on an instance with NVIDIA GPU, it's recommended to install hf-serve with flash-attn extra in order to benefit from accelerated inference:

uv sync --active --frozen --extra cuda --extra flash-attn --preview-features extra-build-dependencies

🔵 Run sentence-transformers/all-MiniLM-L6-v2 on Azure AI

uv run hf-serve --model-id sentence-transformers/all-MiniLM-L6-v2 --task sentence-similarity --dtype float32 --cloud azure

[!WARNING] Given that Azure AI Foundry and Azure ML expect the inference route to be /score rather than /predict, which is the standard for Inference Endpoints API, and since /score is a redirect to /predict, then we need to send the curl request with the -L/--location flag so that it follows the redirect, otherwise we get an HTTP 307.

curl -L http://localhost:8080/score -H "Content-Type: application/json" -d '{"inputs":{"source_sentence":"What is Deep Learning?","sentences":["Deep Learning is...","Deep Learning is not..."]}}'

👂 Run facebook/wav2vec2-base-960h an automatic-speech-recognition model

[!NOTE] Before running automatic-speech-recognition or really any of audio-classification or zero-shot-audio-classification you will need to install some system dependencies in advance for those to work as ffmpeg and libmagic-dev.

uv run hf-serve --model-id facebook/wav2vec2-large-960h --task automatic-speech-recognition --dtype float16

[!WARNING] On MacOS, if you installed ffmpeg via brew, you will need to set the following environment variable in advance DYLD_FALLBACK_LIBRARY_PATH=/opt/homebrew/lib

Reference: https://github.com/pytorch/torchcodec/issues/570#issuecomment-2913609176

And, then you can send a sample request as:

curl -L http://localhost:8080/predict \
    -H "Content-Type: application/json" \
    -d '{"inputs":"https://huggingface.co/datasets/Narsil/asr_dummy/resolve/main/1.flac"}'

[!WARNING] Given the nature of some tasks that need to support JSON, forms, and files, the /predict method for those is a redirect to the respective inner endpoint: /predict-json, /predict-form, and /predict-file. Those are non-standard but required to keep full compatibility with the current Hugging Face Inference Endpoints API Specification, but in reality the redirect response (HTTP 307) shouldn't be used as an routing route, but rather dedicated routes for those.

[!NOTE] The OpenAI Audio Transcriptions API is still not yet part of hf-serve but it's on the roadmap and it will be released soon, stay tuned!

🔈 Run facebook/wav2vec2-lv-60-espeak-cv-ft (with phonemizer and espeak)

[!NOTE] Some models as e.g. facebook/wav2vec2-lv-60-espeak-cv-ft, rely on phonemizer for the "phonemization" of words and texts in many languages, based at the same time on different Text-To-Speech (TTS) backends as e.g. espeak-ng which is supports a lot of languages and IPA (International Phonetic Alphabet). This being said, such models require custom dependencies that need to be installed beforehand as those don't come as default hf-serve dependencies; whilst those can be installed as e.g. on MacOS:

brew install ffmpeg
brew install espeak

[!WARNING] Beware that when installing ffmpeg with brew on a specific version as e.g. brew install ffmpeg@7 as it will be installed as "keg-only", meaning that it won't be symlinked into /opt/homebrew, meaning that the path to the library won't be /opt/homebrew/lib but rather /opt/homebrew/opt/ffmpeg/lib instead, meaning that on MacOS you'll need to set DYLD_FALLBACK_LIBRARY_PATH to wherever the ffmpeg library is installed in.

To run facebook/wav2vec2-lv-60-espeak-cv-ft on e.g. MacOS, you need to run the following:

DYLD_FALLBACK_LIBRARY_PATH=/opt/homebrew/lib uv run hf-serve --model-id facebook/wav2vec2-lv-60-espeak-cv-ft --task automatic-speech-recognition --dtype float16 --device mps

Note that if you have installed another version of ffmpeg with brew as e.g. brew install ffmpeg@7, you should use the following command instead:

DYLD_FALLBACK_LIBRARY_PATH=/opt/homebrew/opt/ffmpeg@7/lib uv run hf-serve --model-id facebook/wav2vec2-lv-60-espeak-cv-ft --task automatic-speech-recognition --dtype float16 --device mps

The main difference relies on the path used for DYLD_FALLBACK_LIBRARY_PATH which is now pointing to the exact brew-installed version of ffmpeg instead. More information on the compatibility issues with ffmpeg, torchcodec and torch at https://github.com/meta-pytorch/torchcodec?tab=readme-ov-file#installing-torchcodec.