Sandbox with MCP

Claude Cowork can manage macOS VMs natively using Lume's MCP connector. Instead of manually starting VMs and providing SSH credentials, Cowork uses MCP tools to control the full VM lifecycle.

How it works

┌─────────────────────────────────────────────────────────────────┐
│                      Your Mac (Host)                            │
│                                                                 │
│  ┌──────────────────┐           ┌───────────────────────────┐  │
│  │ Claude Cowork    │◄── MCP ──►│ Lume MCP Server           │  │
│  │ (Desktop app)    │  (stdio)  │ (lume serve --mcp)        │  │
│  └──────────────────┘           └─────────────┬─────────────┘  │
│                                               │                 │
│                                               │ VM Control      │
│                                               ▼                 │
│  ┌─────────────────────────────────────────────────────────────┐│
│  │                   macOS VM Sandbox                          ││
│  │  Cowork can: list, run, stop, clone, delete, exec commands  ││
│  └─────────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────────┘

Prerequisites

Lume installed with MCP support
A sandbox VM created with --unattended tahoe
sshpass for command execution: brew install hudochenkov/sshpass/sshpass

Setup

1. Configure Claude Desktop

Add the Lume MCP server to your Claude Desktop config:

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "lume": {
      "command": "lume",
      "args": ["serve", "--mcp"]
    }
  }
}

If lume isn't in your PATH, use the full path: /Users/yourname/.local/bin/lume

2. Restart Claude Desktop

After saving the config, restart Claude Desktop. The Lume tools will now be available to Cowork.

3. Create a sandbox VM

If you haven't already:

lume create sandbox --os macos --ipsw latest --unattended tahoe

Available MCP tools

Tool	Description
`lume_list_vms`	List all VMs with status and IP addresses
`lume_get_vm`	Get detailed VM info
`lume_run_vm`	Start a VM with optional shared directory
`lume_stop_vm`	Stop a running VM
`lume_clone_vm`	Clone a VM (for golden images)
`lume_delete_vm`	Delete a VM
`lume_exec`	Execute commands inside the VM

Example workflow

Ask Cowork:

"Start my sandbox VM with ~/project shared, then run the tests in the shared folder."

Cowork will:

[Calls lume_run_vm with name="sandbox", shared_dir="~/project"]
VM 'sandbox' started successfully.

[Calls lume_exec with name="sandbox", command="cd /Volumes/My\\ Shared\\ Files && npm test"]

> test@1.0.0 test
> jest

PASS  src/app.test.js
  42 passing (1.2s)

All tests passed!

Example session

You: List my VMs and start the sandbox with my project folder shared.

Cowork: I'll check your VMs and start the sandbox.

[Calls lume_list_vms]
Found 2 VMs:
- sandbox (stopped)
- dev-vm (running, IP: 192.168.64.3)

[Calls lume_run_vm with name="sandbox", shared_dir="~/my-project", no_display=true]
VM 'sandbox' started successfully.

[Calls lume_get_vm with name="sandbox"]
sandbox:
  State: running
  IP: 192.168.64.5
  SSH: available

The sandbox is now running. Your project files are available at /Volumes/My Shared Files
inside the VM. What would you like me to do next?

Resetting the sandbox

Ask Cowork:

"Reset the sandbox to a clean state using the golden image."

[Calls lume_stop_vm with name="sandbox"]
VM stopped.

[Calls lume_delete_vm with name="sandbox"]
VM deleted.

[Calls lume_clone_vm with name="sandbox-golden", new_name="sandbox"]
VM cloned successfully.

[Calls lume_run_vm with name="sandbox", no_display=true]
VM 'sandbox' started from clean state.

Advantages over SSH

Feature	SSH (Claude Code)	MCP (Claude Cowork)
VM lifecycle	Manual (`lume run/stop`)	Automated via tools
IP lookup	Manual (`lume get`)	Automatic
Credentials	User provides	Configured once
Reset workflow	Script required	Natural language

With MCP, Cowork can manage the entire VM lifecycle through conversation.

Troubleshooting

Cowork doesn't see Lume tools

Check claude_desktop_config.json syntax
Verify lume serve --mcp works: npx @modelcontextprotocol/inspector lume serve --mcp
Restart Claude Desktop completely

lume_exec fails

Ensure sshpass is installed:

brew install hudochenkov/sshpass/sshpass

VM has no IP address

The VM might not be fully booted. Wait a few seconds and try again, or check with lume get sandbox.

Next steps

Stock Analysis with Numbers — Use macOS-only apps via MCP
MCP Server Reference — Full MCP documentation
Claude Code Sandbox — SSH-based alternative

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