> ## Documentation Index
> Fetch the complete documentation index at: https://cortex-foundation-add13747-droid-1a2462c9-cor-444-sanitize.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Code on desktop

> This PC and SSH hosts for Code sessions exist on the desktop app and the CLI. The browser stays Cloud-only — that is where the code runs, not a missing feature.

In the browser, a Code session runs in the Cloud. Install the [Cortex desktop app](/getting-started/desktop) or the [CLI](/cli) and two more hosts appear: **This PC**, which runs the workspace tools on your own machine, and **SSH**, which runs them over the shell of a host you register.

## Where each host lives

| Host        | Browser | Desktop app | CLI           | Desktop for the agent |
| ----------- | ------- | ----------- | ------------- | --------------------- |
| **Cloud**   | Yes     | Yes         | Yes (default) | No — headless guest   |
| **This PC** | No      | Yes         | Yes, opt-in   | Your machine          |
| **SSH**     | No      | Yes         | Yes, opt-in   | Shell only            |

Web Code is Cloud-only by design: the browser has no way to run tools on your disk. That is host placement, not a missing catalog entry.

## This PC

The agent works in a project directory on your machine, using your toolchains, your network, and your hardware. Approvals and sandbox policy apply exactly as they do elsewhere — see [Modes and permissions](/cli/modes-and-permissions) for the CLI's controls.

Good for: private dependencies, local databases, GPU work, anything the Cloud guest cannot reach.

## SSH

The agent runs shell tools on a host you register, over SSH. There is no desktop on that host; it is a shell. Good for: build boxes and servers you already operate.

## Choosing a host

**Desktop app:** pick the host when you start the session.

**CLI:** the TUI and `cortex exec` use the Cloud unless you opt in:

```bash theme={null}
CORTEX_COMPUTER=this_pc cortex          # run tools on this machine
CORTEX_COMPUTER=ssh cortex              # run tools over SSH
CORTEX_SSH_HOST=build-box cortex        # naming an SSH host also selects SSH
```

This PC and SSH need an **already connected Code session**. Cortex will not create one on the fly and will not substitute the Cloud silently; if you select a host without a connected session, the CLI tells you so in plain words. Either resume a session that already has the host, or unset `CORTEX_COMPUTER` to use the Cloud. See [CLI configuration](/cli/configuration).

<Frame caption="The CLI composer once a host is connected. Whichever host runs the tools, the session looks the same from here.">
  <img src="https://mintcdn.com/cortex-foundation-add13747-droid-1a2462c9-cor-444-sanitize/f_vF1T0UHRUAu9OO/images/cli/runtime/40x12/composer-hover.png?fit=max&auto=format&n=f_vF1T0UHRUAu9OO&q=85&s=87bee620798d58f1fd1e51fa5649a16e" alt="Cortex CLI composer with the pointer over it, rendered in a 40 by 12 terminal" width="432" height="296" data-path="images/cli/runtime/40x12/composer-hover.png" />
</Frame>

## Bot has the same shape

Bot's Computer rail follows the same rule: **Cloud** in the browser, **This PC** on the Bot desktop app, **SSH** as shell only. See [Bot computer](/bot/computer).

## Related

* [Desktop app](/getting-started/desktop) — download and sign in.
* [Cloud runtimes](/code/cloud) — the default host.
* [Code in the terminal](/code/cli)