> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tensorlake.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Read-only Mounts

> Mount fixed commits or branch-following directories for reproducible inputs and shared assets.

Use read-only mounts when a sandbox needs files but should not write to them.

There are two read-only modes:

* **Pinned**: resolves a branch, tag, or commit once and never changes.
* **Following**: tracks a branch and refreshes as that branch moves.

## Pinned Read-only Mount

A pinned mount is best for reproducible builds, evals, benchmarks, and released assets.

```bash theme={null}
$ tl fs mount agent-outputs:9f2a1c8e4d6b1a0f3c7e9d2b8a4f6c1e0d3b7a99 /release --mode ro
```

Use a commit hash when the input must stay fixed for the lifetime of the sandbox.

## Following Read-only Mount

A following mount is best for shared skills, prompts, docs, configs, and dependencies.

```bash theme={null}
$ tl fs mount agent-outputs:main /skills --mode ro
Mounted agent-outputs:main at /skills (workspace 7c2e9f0a1b3d, read-only, follows the branch)
Reading commit 9f2a1c8e4d6b1a0f3c7e9d2b8a4f6c1e0d3b7a99. New commits appear as the followed ref advances.
```

When `main` moves, Tensorlake refreshes only the paths that changed. Unchanged files keep their warm cache.

For a complete asset distribution workflow, see [Distribute Files to Agents](/filesystems/distribute-files).

## Choosing Between Them

| Need                                                         | Use                                                |
| ------------------------------------------------------------ | -------------------------------------------------- |
| Every run must see the same files                            | Pinned read-only mount                             |
| Many sandboxes should receive updates without image rebuilds | Following read-only mount                          |
| An agent needs to write files                                | [Writable mount](/filesystems/writable-workspaces) |