# Hugging Face Models Tensormorph can open a checkpoint hosted on the Hugging Face Hub directly, without a separate manual download step. This page covers how a Hub model is addressed and cached, not how to author or publish one - Tensormorph is a consumer of Hub-hosted checkpoints, not a Hub client. ## Addressing a model by revision A Hub repository is a Git-backed store where every commit, branch, and tag is a valid **revision**. Tensormorph accepts any of the three when you open a Hub model: - `org/model` - resolves to the `main` branch. - `org/model@a1b2c3d` - pins to an exact commit hash. - `org/model@v2` - resolves a tag or branch name. Pinning by commit hash is the only one of the three that's guaranteed stable: a branch or tag can move to a different commit later, while a hash always refers to the same content. When Tensormorph records what a comparison or a workspace was built from, it stores the resolved hash, not the branch or tag name you typed - the same principle behind the commit-pin mechanism described in [Merge Conflicts](/docs/compare-and-morph/merge-conflicts). ## Local cache layout Once a Hub model has been opened, Tensormorph keeps a local, content-addressed cache so re-opening the same revision - or a different revision that shares most of its tensors - doesn't re-download unchanged bytes. The layout mirrors the Hub's own local-cache convention: ``` / ├── models----/ │ ├── blobs/ # file contents, stored once per content hash │ ├── refs/ # branch/tag name → resolved commit hash │ └── snapshots/ # one folder per commit hash, symlinked into blobs/ ``` - **`blobs/`** holds every distinct file's bytes exactly once, keyed by content hash - if two revisions share a tensor file unchanged, it's stored once and referenced twice. - **`refs/`** maps a mutable name (`main`, `v2`) to the commit hash it currently resolves to, so Tensormorph can tell you a branch pointer moved without re-fetching anything. - **`snapshots/`** gives each commit hash its own folder of symlinks back into `blobs/`, so "the full set of files at commit X" is always a cheap directory listing, never a copy. This is the same content-addressed, symlink-snapshot pattern used for Lob's own local object cache - Tensormorph didn't invent a second scheme for Hub-sourced models. ## Instant tree population Most Hub-hosted checkpoints ship as safetensors, so opening one gets the same near-instant tree population described in [Safetensors](/docs/working-with-models/safetensors): Tensormorph range-fetches each shard's header before downloading any weight bytes, and the Outliner populates from those headers alone. ## Related resources - [Sharded Checkpoints](/docs/working-with-models/sharded-checkpoints) - most Hub models above a few gigabytes ship as multiple safetensors shards with an index file. - [Model Cards](/docs/hub-and-collaboration/model-cards) - the structured metadata attached to a Hub repository, beyond what's in the checkpoint file itself.