MCP server

box is a cloud Linux desktop for your AI. Add it to your AI app as a remote MCP server and the AI gets a real computer of its own: Chrome, a shell and a full Ubuntu desktop. It can browse, click, type, read the screen and run commands there, while your own computer stays free.

• A desktop, ready on first connect. One box per account, with Chrome and a persistent shell.
• Sleeps when idle. It wakes in about a second when your AI connects; files and state persist.
• Watch it live. See the screen at https://box.simular.ai/box and take control when you need to.

Once box is connected, try asking your AI:

• "Use box to open Chrome, search Google for "Simular", and summarize the top 3 results."
• "Use box to open GitHub Trending and tell me what today's top 3 repositories do"
• "Use box to go to news.ycombinator.com and give me today's top 5 stories in a table"

Connect with one command

Run this in a terminal (it needs Node.js 18.17 or later):

npx @simular-ai/box connect

It finds the AI apps on this computer (Claude Code, Codex, Cursor, OpenCode, Hermes, OpenClaw and VS Code), asks which ones should use box, and adds the box server to each in its own format. Other servers and settings in those files are left alone, each changed file gets a backup next to it, and running it again changes nothing. Each app then signs you in to box in the browser the first time it connects (OAuth); there is no key to paste.

• --client <ids> picks the apps, comma-separated: claude-code, codex, cursor, opencode, hermes, openclaw, vscode, claude-desktop.
• --yes doesn't ask; with no --client, it uses every app it found.
• --dry-run shows what would change without writing anything.
• --name <name> uses another server name instead of box, when the app already has a different server called box (box.com's, for example).
• --auth key (Hermes and OpenClaw only) uses a personal key instead of OAuth, for an always-on server with no browser. The key comes from BOX_TOKEN or a hidden prompt, never from the command line.
• npx @simular-ai/box doctor checks box's setup in each app; npx @simular-ai/box remove undoes connect.

Claude Desktop keeps remote servers as connectors you add in the app, so for it connect prints the steps. Claude on the web, ChatGPT, Gemini, Gemini CLI and DeepSeek Harness aren't covered: follow their steps under Set up in your app. The installer's source and README: simular-ai/box-plugin.

Server URL and sign-in

box is one MCP server, named box:

https://mcp.box.simular.ai/mcp

Added box before November 4, 2026? Its URL used to be https://relay.simular.cloud/mcp. That URL still answers, but signing in through it can fail. Switch to the URL above: run the command below, which replaces the old entry, or in an app you set up by hand, remove box and add it again with the new URL.

npx @simular-ai/box@latest connect

You sign in with your Simular account the first time your AI connects (MCP authorization, OAuth 2.0): your app opens a browser page where you approve which boxes it may use and for how long. There is no key to copy or paste.

For an app that can't sign in and can only send a fixed header, create a personal key at https://box.simular.ai/keys and set it in the app's config as Authorization: Bearer <key>. The key is shown once; keep it out of chats and shared files.

Every app you connected and every key is listed at https://box.simular.ai/keys, where you can revoke any of them.

Set up in your app

The installer above covers most coding apps. Claude adds box in one tap; the other apps take a few steps:

Claude (claude.ai and the desktop app)

Add to Claude

Claude opens with box filled in, on your phone or your computer. Tap Continue, then sign in to box and approve.

Claude Free allows one custom connector. On Team and Enterprise, an Owner adds box for the organization first.

Or by hand:

1. In Claude (claude.ai or the desktop app), open Settings → Connectors.
2. Click Add custom connector. Name it box and paste the URL below; leave the advanced settings empty.
3. Click Connect, sign in to box and approve. Then turn box on in a chat’s tools menu.

The URL is https://mcp.box.simular.ai/mcp.

ChatGPT

ChatGPT adds box as a custom MCP server, made into a plugin. ChatGPT can't add it for you; do these steps yourself. Adding happens once on chatgpt.com, on a computer (the ChatGPT app on iPhone and Android can't add one); after that box works in the ChatGPT app.

1. On a computer, open chatgpt.com/plugins (Plugins in ChatGPT’s sidebar). Click Add, then Add custom MCP server.
2. Name it box. Under Connection, paste the URL below as the Server URL, and choose OAuth as the authentication.
3. Select I understand and want to continue, then Create as a plugin. Install the plugin, then sign in to box and approve when asked.
4. In a chat, type @ and pick box, then ask for a task.

The URL is https://mcp.box.simular.ai/mcp.

Don't see Add custom MCP server? Your ChatGPT plan or workspace may not allow custom servers yet; Claude can add box in one tap, on a phone too.

Gemini (gemini.google.com)

Gemini adds box as a custom app. Gemini can't add it for you; do these steps yourself on the web (the mobile app can't add one, but uses it once it is added). Google allows custom apps only for a personal Google Account (not a work or school one), for people 18 or older in the US, in English, with Keep Activity on (Google's help page). Otherwise use Gemini CLI.

1. On a computer, open gemini.google.com. Click Settings, then Connected Apps (if you don’t see it, click Personal Intelligence first).
2. Under Custom apps, click Add a custom app and paste the URL below. Leave Advanced features empty.
3. Click Next, then sign in to box and approve.
4. In a chat, type @ and pick box, then ask for a task. Once added, box works in the Gemini mobile app too.

The URL is https://mcp.box.simular.ai/mcp.

Claude Code

claude mcp add --transport http box https://mcp.box.simular.ai/mcp

Then run /mcp in Claude Code, pick box and choose Authenticate. Sign in and click Approve in the browser.

Codex app

1. In the Codex app, open Settings, then select MCP servers.
2. Select Add server. Name it box, choose Streamable HTTP and paste the URL below.
3. Save, then select Restart.
4. Select Authenticate next to box, sign in to box and approve. In a chat, type /mcp to see it.

The URL is https://mcp.box.simular.ai/mcp. The Codex app, the Codex CLI and the IDE extension share one config (~/.codex/config.toml), so adding box once covers all three.

Codex CLI

# ~/.codex/config.toml
[mcp_servers.box]
url = "https://mcp.box.simular.ai/mcp"

# then sign in: codex mcp login box

codex mcp login box opens the browser to sign in.

Cursor

Add to Cursor

Cursor opens and asks to install box; click Install. Or add this to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "box": {
      "url": "https://mcp.box.simular.ai/mcp"
    }
  }
}

Then open Cursor Settings → MCP and click Login next to box.

VS Code

Add to VS Code

VS Code opens and shows box; click Install. Or run MCP: Add Server from the Command Palette, choose HTTP, paste https://mcp.box.simular.ai/mcp and name it box. VS Code asks you to sign in to box when the server starts.

Gemini CLI

gemini mcp add --scope user --transport http \
  box https://mcp.box.simular.ai/mcp

Then start gemini, run /mcp auth box, sign in and click Approve in the browser. /mcp shows whether box is connected; gemini mcp list shows it from your shell. Gemini Code Assist's agent mode in VS Code reads the same ~/.gemini/settings.json, so box shows up there too.

DeepSeek Harness (dsh)

dsh can't sign in, so it uses a personal key. Install the plugin, then set the key in your own terminal:

dsh plugin add https://github.com/simular-ai/box-plugin/releases/download/dsh-v0.2.1/dsh-box.tgz
export BOX_TOKEN=cb_your_key

Create the key at https://box.simular.ai/keys (Create key under Keys and devices; it is shown once), put it in place of cb_your_key, add the line to your shell profile to keep it, and restart dsh. box's tools show up as mcp__box__*.

Any other MCP client

Add one remote MCP server, box, Streamable HTTP, at https://mcp.box.simular.ai/mcp, with no header. Your app signs you in the first time it connects. If it can't sign in, use a personal key as above.

Set up with a coding agent

Paste this into Claude Code, Codex, Cursor or Gemini CLI and the agent adds box for you:

Set up box from https://box.simular.ai/install

Install with your AI has the steps it follows.

Troubleshooting and support

Start with npx @simular-ai/box doctor: it checks box's setup in each app and prints a fix for each problem it finds. Troubleshooting lists the common problems, and support is at support@simular.ai.