# An MCP server for Linux machines

639 Shell is a cloud built to be driven by agents. Its MCP server gives any MCP client (Claude
Code, Codex, Cursor, VS Code Copilot, Gemini CLI, Claude Desktop and others) real Linux machines
to work in: create them, run commands, read and write files and delete them,
within the limits you set.

## Connect

Over SSH, your SSH key is the login: no token to paste.

```sh
claude mcp add 639 -- ssh -T -o BatchMode=yes mcp@shell.639cloud.com
codex mcp add 639 -- ssh -T -o BatchMode=yes mcp@shell.639cloud.com
```

Over HTTPS (Streamable HTTP) at `https://api.shell.639cloud.com/mcp`, with sign-in. It's listed
in the official MCP Registry as `com.639cloud/shell`.

## What the tools cover

- **Machines:** create (Instant machines or full VMs of common distros), list, resize, sleep,
  restart, delete.
- **Work:** run a command with its output, upload and download files.
- **State:** snapshots, undo, forks of a running machine and templates (beta).
- **Safety:** throwaway sandboxes; per-machine network rules; secrets placed at creation; rules
  you write for agents (like a CLAUDE.md for the machine), which they must acknowledge before
  changing anything when you make them required; limits on deletes and calls per person.

## Try it first

```sh
ssh try@shell.639cloud.com github:<your-github-username>
```

A machine for an hour with no sign-up. 639 Shell is an alpha, looking for testers.

More: [Agents and MCP](/docs/agents-mcp) · [Rules for agents](/docs/rules-for-agents) · [API and SDKs](/docs/api-and-sdks)