Docs / Getting started
Models, downloads, and storage
Know what the CLI downloads, where it stores the files, and how much free space the first run needs.
Released models
| Model | Runnable container | Coded transport | Primary use |
|---|---|---|---|
| Neutrino-1 8B | 3.88 GB | 2.56 GB | Default general model and tool caller |
| Neutrino-1 0.6B | 328 MB | 238 MB | Small model and canonical speculative draft |
| Neutrino-1 0.6B-Chat | 328 MB | 238 MB | Small conversational model |
The first-run download plan
The CLI downloads only the files required to run the selected model. GGUF and MLX artifacts are not fetched by default.
| Platform | Downloaded | Steady state | Peak free space |
|---|---|---|---|
| Apple Silicon | 2.56 GB transport | about 3.9 GB | about 6.5 GB |
| Other platforms | 3.88 GB container | about 3.9 GB | about 4 GB |
| 0.6B models | 238 MB transport or 328 MB container | 328 MB | under 600 MB |
On Apple Silicon, the verified transport is deleted after expansion. Set FERMION_KEEP_TRANSPORT=1 if you want to keep it. Set FERMION_DOWNLOAD_ALL=1 only when you intentionally want the whole repository.
Move the model cache
Models use the standard Hugging Face cache under ~/.cache/huggingface/hub. Move all Hugging Face data with HF_HOME, or move only Fermion model downloads with FERMION_CACHE_DIR.
export HF_HOME=/big/disk/hf
# or
export FERMION_CACHE_DIR=/big/disk/fermion
fermion chatA small ~/.cache/fermion directory may also hold generated Transformers configuration directories.
Disk-space checks and interrupted downloads
Before downloading weights, fermion checks the real cache volume against the model manifest. If the volume is too small, it stops before the transfer and prints the cache path, required bytes, available bytes, and the two cache variables above.
If a download or local expansion is interrupted, run fermion info. The command detects incomplete structure and hash mismatches and exits non-zero for automation.