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

# Sandbox providers

> A sandbox provider is where a cloud sandbox runs. Mutagent runs your sessions in its own sandboxes unless you choose another configured sandbox provider.

<Note>
  **Early access.** Cloud sessions and managed agent runs are not open to every account yet: we are
  letting accounts in gradually while we test. They run in a cloud sandbox operated by Mutagent, so
  there is nothing to host. A sandbox with nothing to do for 15 minutes stops; send the session a
  message and it wakes up, delivers your message and carries on in the same conversation.
</Note>

A sandbox provider is where a cloud sandbox runs. Every Helix Cloud task, session and managed agent
run starts a sandbox on one sandbox provider.

Mutagent runs your sessions in its own sandboxes, on the sandbox provider `mutagent-cloud` (Mutagent
Cloud). It is the default, so there is nothing to set up. You choose another
sandbox provider only when the platform has more than one configured.

## How a run picks a sandbox provider

Without a flag, a run uses the default sandbox provider. To choose one, pass `--sandbox-provider`:

```bash theme={null}
mutagent helix --sandbox-provider mutagent-cloud -p "<task>"
mutagent helix agent "<definition>" --sandbox-provider mutagent-cloud --rpc
```

The flag works for tasks, sessions and managed agent runs. An unknown name is refused, and the error
lists the names you can use.

To see the names and the default before a run:

```bash theme={null}
mutagent sandbox providers
mutagent sandbox presets
```

A preset is a named sandbox definition on a sandbox provider. `--preset <name>` picks one; without
it, the default preset is used. See [mutagent sandbox](/cli/commands/sandbox).

## What a sandbox provider does not decide

A sandbox provider decides only where the sandbox runs. The rest of the run comes from other places:

| Part of the run | Where it comes from |
| - | - |
| The model | Your [LLM providers](/helix/cloud/setup) and the `--model` flag |
| Variables and secrets for tools | The [Environment](/helix/cloud/environments) you load with `--env` |
| The agent | The orchestrator, your definition, or a [managed agent](/helix/cloud/managed-agents) |

Changing the sandbox provider does not change the model, the Environment or the agent.

## Idle sandboxes

The same idle policy applies on every sandbox provider:

* A sandbox stops after 15 minutes with no activity. A turn the agent is still working on counts as
  activity, for up to 4 hours.
* Before it stops, an interactive session is checkpointed.
* To continue, send the session a message. It wakes on a new sandbox from its last checkpoint and
  gets the message; the reference stays the same:

```bash theme={null}
mutagent helix session send <reference> "carry on"
```

[More on sessions](/helix/cloud/sessions)

## Managed agents

Not every sandbox provider can receive a managed agent package yet. Deploy, activate and a run refuse
a sandbox provider that cannot, and the error names it. See
[Managed agents](/helix/cloud/managed-agents#environments-and-slots).


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