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

# Warm Slots

> Pre-provisioned workspace snapshots that let tasks start fast, bounded by your subscription tier.

A warm slot binds a project to a pre-provisioned VM snapshot so that tasks for that project start from a warm machine instead of a cold boot. Each subscription tier includes a fixed number of slots, and you assign projects to them.

## Tier-Bounded Quota

The number of warm slots you can use is set by your [subscription tier](/concepts/pricing-and-tiers):

| Tier    | Warm slots |
| ------- | ---------- |
| Free    | 1          |
| Starter | 2          |
| Pro     | 3          |
| Max     | 5          |

Slots beyond your tier's quota cannot be assigned. The web app and the [`aether warm-slot`](/cli/warm-slot) CLI render a fixed grid of slot cards sized to your tier; empty cards show as `unassigned`.

## Requirements

A project can only be assigned to a warm slot if it meets two conditions:

* It is **linked to a GitHub repository** — the snapshot is built against the repo's source.
* It uses **pool-eligible hardware** — its [runtime class](/concepts/workspaces) must be one that the warm pool supports.

Assigning a project to an occupied slot evicts the project that was there before.

## Slot Statuses

| Status         | Meaning                                                       |
| -------------- | ------------------------------------------------------------- |
| `unassigned`   | No project bound to the slot.                                 |
| `provisioning` | Building the snapshot for the assigned project.               |
| `ready`        | A warm snapshot is available for fast starts.                 |
| `refreshing`   | Rebuilding the snapshot (for example after the repo changes). |
| `stale`        | The snapshot needs a refresh before it can warm-start again.  |

## Refreshes Cost Credits

Building or rebuilding a slot's snapshot consumes [credits](/concepts/billing-and-credits) under the `snapshot_refresh` debit reason — distinct from the VM-runtime credits a task itself spends. Keeping a project warm therefore has an ongoing cost when its snapshot is rebuilt.

## Managing Slots

<Tabs>
  <Tab title="Web">
    Open the warm-slots grid in settings, then assign a project to a slot or release a slot you no longer need.
  </Tab>

  <Tab title="CLI">
    ```bash theme={null}
    aether warm-slot list
    aether warm-slot assign --slot 0 --project <project-id>
    aether warm-slot release <slot-id>
    ```
  </Tab>
</Tabs>

You can also manage slots over the API — see [warm-slot endpoints](/api-reference/account/billing/get-billing-slots).