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

# The runs-on label

> One label selects a Trunk runner and sets its options.

You point a job at Trunk Runners with one `runs-on` label.

```yaml theme={"system"}
runs-on: trunk=${{ github.run_id }}-${{ github.run_attempt }}
```

## Options

| Option | Required | What it sets |
| - | - | - |
| `size` | No | The machine size, which sets the CPU count. See [Machine sizes](https://docs.trunk.io/runners/actions/sizes.md). |
| `memory` | No | The memory per CPU: `low`, `standard`, or `high`. See [Machine sizes](https://docs.trunk.io/runners/actions/sizes.md#sizes). |
| `template` | No | The template (a prepared environment) for the job. See [Templates](https://docs.trunk.io/runners/actions/templates.md). |
| `cache` | No | `trunk` or `github` to choose the cache for `actions/cache`. See [Caching](https://docs.trunk.io/runners/cache/index.md). |

## Examples

A large runner with high memory:

```yaml theme={"system"}
runs-on: trunk=${{ github.run_id }}-${{ github.run_attempt }}..size=large..memory=high
```

A large runner with low memory, for a job that needs CPUs but little memory:

```yaml theme={"system"}
runs-on: trunk=${{ github.run_id }}-${{ github.run_attempt }}..size=large..memory=low
```

A job on a chosen template:

```yaml theme={"system"}
runs-on: trunk=${{ github.run_id }}-${{ github.run_attempt }}..size=medium..template=<template-id>
```

See the [full label format](https://docs.trunk.io/runners/reference/runs-on-grammar.md) for every option in
one table.