# What is a remote development environment?

A remote development environment is a machine elsewhere. It holds your code,
tools and processes. You drive it from your local editor.

**On Runtime, a sandbox is a remote development environment. SSH, VS Code and
JetBrains connect to it through the API. It costs $0.03125 an hour at
2 vCPU and 4 GiB while you read and type.** Runtime bills measured CPU. An open
editor is not billed as two busy cores ([pricing](/docs/pricing)).

## Why it matters for AI agents

When a coding agent edits and tests in a sandbox, a person often wants to open
that exact machine. They read what changed, run the failing test and take over.
If the agent's environment is also a remote development environment, nothing
has to be copied back to a laptop for inspection. The reverse works too. An
agent can be given a person's environment to finish a task in. The person's own
machine never runs the agent's commands.

## Remote development in facts

| Property          | What it means                                       | On Runtime                                                       |
| ----------------- | --------------------------------------------------- | ---------------------------------------------------------------- |
| Editor connection | The editor's server side runs on the remote machine | VS Code Remote - SSH and JetBrains Gateway via `<id>.runtime`    |
| Shell             | A login on the remote machine                       | `runtime sandboxes ssh <id>`, as the user `runtime`, with `sudo` |
| Ports             | A dev server reached from the local browser         | `runtime sandboxes port-forward <id> 3000`, any TCP port         |
| Isolation         | The remote machine is not your laptop               | A Firecracker microVM with its own kernel                        |
| Idle time         | What happens while nobody types                     | Pause keeps files, memory and processes while you have credit    |
| Always on         | A machine that does not stop                        | `persistent: true` keeps a paid sandbox running until stopped    |
| Base system       | What is installed                                   | Ubuntu 24.04, Python 3.12, Node.js 24, Bun, git, gcc             |

VS Code describes Remote - SSH as a way to "open a remote folder on any remote
machine, virtual machine, or container with a running SSH server". Its
extensions run on that remote machine.

## Connect your editor

Install the SSH entry once. After that, each sandbox is a host. Its host name
is its id or its name:

```bash no-run
runtime sandboxes ssh config --install
runtime sandboxes ssh my-env            # a shell
ssh my-env.runtime                    # plain OpenSSH, scp and rsync too
runtime sandboxes port-forward my-env 5173
```

In VS Code, run **Remote-SSH: Connect to Host** and enter `my-env.runtime`. The
sandbox opens no port to the internet. Each connection is a WebSocket through
Runtime's API, authenticated with your key
([SSH and editors](/docs/editors)).

To create the environment in code, and find it again by name:

```ts check
import { Runtime } from "withruntime";

const runtime = new Runtime();
const env = await runtime.sandboxes.create({
  name: "my-env",
  getOrCreate: true,
  idlePauseSeconds: 1800,
});
console.log(env.id, env.state);
```

`getOrCreate` returns the sandbox that already has the name. If the sandbox was
paused, it wakes it. `idlePauseSeconds` pauses the sandbox after half an hour
with no request.

## Keep it running while you work

An open SSH connection keeps a sandbox running. There is no time limit by
default, so a long session needs no setup. For a machine that never pauses,
even with nobody connected, create a paid sandbox with `persistent: true`. It
runs while credit lasts. Connecting to a paused sandbox wakes it, as any command
does.

## Related

- [How to give every user their own cloud dev environment](/use-cases/per-user-dev-environments)
- [GitHub Codespaces vs an agent sandbox](/compare/github-codespaces-vs-agent-sandbox)
- [How to pause and resume a sandbox](/how-to/pause-and-resume-a-sandbox)
- [SSH and editors](/docs/editors)

## Sources

- [VS Code: Remote Development using SSH](https://code.visualstudio.com/docs/remote/ssh), read 25 October 2026

Facts on this page were checked on 25 October 2026.