# `once cache gc`

Reclaim local cache space down to a size budget.

## Synopsis

```text
once cache gc [OPTIONS]
```

## Description

Removes the oldest blobs and action results until the local store fits within `--max-size`, defaulting to 20 GB when the flag is omitted. Safe to run at any time: an action whose outputs get evicted simply re-executes on its next build. Only the local tier is collected; a remote cache is never touched.

## Options

| Flag | Value | Default | Description |
| --- | --- | --- | --- |
| `--max-size` | `<SIZE>` |  | Maximum local cache size to keep. Plain bytes or a human suffix: `500MB`, `2GiB`, `750k`. Decimal suffixes (KB/MB/GB/ TB) are powers of 1000; binary suffixes (KiB/MiB/GiB/TiB) are powers of 1024. Defaults to 20 GB when omitted. |
| `--dry-run` | (flag) |  | Report what would be reclaimed without deleting anything. |