Environment variables reference

UltraCompress respects a small set of environment variables. They are intentionally minimal; the CLI is not configurable through a sprawling configuration file.

UltraCompress-specific

Variable	Default	Effect
UC_HF_ORG	sipsalabs	Override the Hugging Face Hub organization queried by uc list. Useful for testing forks or mirrors.
UC_HF_COLLECTION_TAG	ultracompress	Override the Hugging Face Hub tag filter used by uc list.
UC_BENCH_SEED	42	Override the deterministic seed used by uc bench.
UC_BENCH_OUTPUT_DIR	./bench-results	Override the default --output-dir for uc bench.
UC_VERBOSE	unset	If set to 1, print extra diagnostic logs to stderr.
UC_NO_BANNER	unset	If set to 1, suppress the _banner() printout (useful for scripted use).

Inherited from huggingface_hub

UltraCompress uses huggingface_hub for Hub access; the standard Hub env vars all apply.

Variable	Effect
HF_HOME	Cache root (default: ~/.cache/huggingface)
HF_ENDPOINT	Override the API endpoint (use https://hf-mirror.com for the China mirror)
HF_TOKEN	Hugging Face access token (alternative to huggingface-cli login)
HF_HUB_DOWNLOAD_TIMEOUT	Per-file download timeout in seconds (default 30)
HF_HUB_PARALLEL_DOWNLOAD_THREADS	Concurrent download threads (default 8)
HF_HUB_OFFLINE	If set to 1, never call the Hub; serve only from local cache
HF_HUB_DISABLE_PROGRESS_BARS	Hide tqdm progress bars

Inherited from transformers (when running uc bench)

Variable	Effect
TRANSFORMERS_OFFLINE	If set to 1, never call the Hub from transformers
TRANSFORMERS_CACHE	Override the model cache directory

Inherited from PyTorch

Variable	Effect
CUDA_VISIBLE_DEVICES	Limit which GPUs are visible to PyTorch
PYTORCH_CUDA_ALLOC_CONF	Memory allocator tuning (e.g., max_split_size_mb:512)

CI-relevant

Variable	Effect
CI	Most CLI tools detect CI=true and disable color/animation; UltraCompress respects this for rich output
NO_COLOR	If set, all colored output is disabled (per https://no-color.org)

Examples

Use a different HF Hub org for testing

export UC_HF_ORG=your-org
uc list   # queries hf.co/your-org instead of hf.co/sipsalabs

Run completely offline

export HF_HUB_OFFLINE=1
uc info ./models/sipsalabs_<model-id>   # works as long as files are cached

Quiet mode for scripts

export UC_NO_BANNER=1
uc list --json | jq '.'   # clean JSON output without the banner

Limit GPUs for uc bench

export CUDA_VISIBLE_DEVICES=0   # use only the first GPU
uc bench ./models/sipsalabs_<model-id> --tasks hellaswag --limit 100