---
title: Long-running tasks
description: Keep builds, servers and agents running for hours, independent of the command or connection that started them.
---

A sandbox runs until you stop it. Nothing stops it for being idle; only reaching your org's [monthly sandbox-hours](/getting-started/limits/#the-monthly-hours-are-a-hard-limit) does. That makes it a good place for work that takes longer than a terminal session: test suites, builds, data processing, servers and AI agents.

## Within one command

`pols exec` runs a command for up to 600 seconds by default. Raise the limit with `--timeout`, up to 86,400 seconds (24 hours):

```sh
pols exec web --timeout 7200 -- bash -lc 'cd app && make release'
```

The command's output streams to your terminal while it runs. Over the API, ask for streaming with `Accept: application/x-ndjson` so you see progress and are not limited to the 4 MiB of collected output.

## Detached from your connection

For anything that should outlive the call that started it, start it in the background inside the sandbox and check on it later. `tmux` is installed in every sandbox:

```sh
pols exec web -- tmux new-session -d -s build 'cd ~/app && make release > ~/build.log 2>&1'
pols exec web -- tail -n 20 /home/user/build.log
pols exec web -- tmux has-session -t build    # exit code 0 while it runs
```

To watch it interactively, open a shell over [SSH](/access/ssh/) with `pols ssh web` and run `tmux attach -t build`; detach again with `Ctrl-b d`.

For services that should come back after a [stop and resume](/sandboxes/lifecycle/#stopping-and-resuming), make them start at boot, like on any server: a systemd unit (`sudo systemctl enable --now my-service`) or a Docker container with a restart policy (`docker run -d --restart unless-stopped ...`).

## Agents that work for hours

Claude Code and Codex are preinstalled. Start an agent in a tmux session the same way, and give it the keys it needs through the [vault](/sandboxes/vault/):

```sh
pols new --name agent --secret ANTHROPIC_API_KEY
pols exec agent -- tmux new-session -d -s claude 'cd ~/repo && claude -p "Fix the failing tests" > ~/claude.log 2>&1'
```

You can watch an agent that uses the browser on the [desktop](/access/desktop/), and record the desktop with `pols-record start` inside the sandbox.

## Things to keep in mind

- **Stopping ends processes.** `pols stop` shuts the VM down; work in progress is lost unless it is on disk. Reaching the monthly hours stops sandboxes the same way.
- **Running time is billed.** A sandbox that waits for something costs the same as one that computes. Stop it when the work is done.
- **Keep results outside the sandbox.** Disks are not backed up yet; push results to git or copy them out with `pols cp`.