# box by Simular

> box is a cloud Linux desktop for your coding agent. Add it to Claude Code, Codex or Cursor as a remote MCP server and the agent can use a real computer: open a browser, click, type, read the screen and run commands.

## Key facts

- Product: box, from [Simular](https://www.simular.ai/). Portal: https://box.simular.ai.
- Interface: one hosted MCP server, `box` (`https://relay.simular.cloud/mcp`), authenticated with your API key (`Authorization: Bearer sapi_...`). Its tools work on your box (shell, browser, screenshot, desktop tools), waking it when it sleeps, and manage it (list, wake, save, restore). No local package to install.
- The computer: one cloud Linux desktop per account. It sleeps when no one uses it and wakes when your agent connects.
- Cost: the box itself is free. Its model calls use your account's daily credits.

## Getting started

1. Sign in with Google at [https://box.simular.ai/sign-in](https://box.simular.ai/sign-in). Your first API key is created for you; keys start with `sapi_`.
2. Easiest: tell your coding agent `Set up box from https://box.simular.ai/install` and it does the rest. To do it yourself, add the server below, replacing `sapi_YOUR_KEY` with your key.
3. Ask the agent for a task, for example: `Use box to open Chrome, search Google for "Simular", and summarize the top 3 results.`

### Claude Code

```bash
claude mcp add --transport http box https://relay.simular.cloud/mcp --header "Authorization: Bearer sapi_YOUR_KEY"
```

### Codex

```toml
# ~/.codex/config.toml
[mcp_servers.box]
url = "https://relay.simular.cloud/mcp"
http_headers = { "Authorization" = "Bearer sapi_YOUR_KEY" }
```

### Cursor

```json
{
  "mcpServers": {
    "box": {
      "url": "https://relay.simular.cloud/mcp",
      "headers": {
        "Authorization": "Bearer sapi_YOUR_KEY"
      }
    }
  }
}
```