MCP extension · Apache 2.0 at both ends

A real Linux box for Goose.

Goose is built on MCP extensions, and every Containarium box is one. Add a box as an extension and Goose gets a whole Linux machine to work in — persistent, isolated, and not your laptop.

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~ / give Goose its own box

# 1. create a box and write its SSH config
$ containarium create goose-box
$ containarium ssh-config sync

# 2. add it as a Goose extension (~/.config/goose/config.yaml)
extensions:
  goose-box:
    type: stdio
    cmd: ssh
    args: [goose-box, agent-box]
    enabled: true

Extensions

Goose's developer tools run where Goose runs. Give it somewhere else.

Goose's built-in developer extension runs shell commands and edits files on the machine Goose is running on. Adding a box as an extension gives it a second place to work: a Linux machine where running anything is fine.

Goose on your laptop

Shell commands and file edits land on your own machine, next to your credentials and every other project.

Goose with a box

Shell and file tools that act on a disposable Linux machine holding one project. Keep Goose's desktop app or CLI local; the risky work happens in the box.

Open at both ends

Goose is Apache 2.0 under the Agentic AI Foundation at the Linux Foundation. Containarium is Apache 2.0. No closed layer in between.

Persistent between sessions

Tools installed in the box stay installed, and services the agent starts keep running.

Host what it builds

Publish a port from the box on a TLS hostname with containarium expose-port and share a working URL, not a screenshot.

Connecting

Two ways to point Goose at a box.

As a command-line extension

Add the YAML above to ~/.config/goose/config.yaml, or run goose configure → Add Extension → Command-line Extension with the command ssh goose-box agent-box. Goose gets the box's shell and file tools.

Run Goose inside the box

Open a shell with containarium connect goose-box, install the Goose CLI there, and run it. Its built-in developer tools then act on the box.

Using another agent? The same box works with Claude Code, Cursor, Cline, Codex CLI, Gemini CLI, Aider, OpenHands, or your own agent. Need a GPU in it? That works too.

FAQ

Common questions

How do I give Goose a sandbox?

Create a Containarium box, run containarium ssh-config sync, then add a command-line (stdio) extension to Goose with the command ssh goose-box agent-box. Goose then gets shell and file tools that run inside the box.

Does Goose work with remote MCP servers?

Yes. Goose extensions are MCP servers; a command-line extension can be any command, including ssh to a remote box.

Is the box persistent?

Yes. A box is a long-lived LXC container or Kubernetes pod; files, installed tools and running services survive until you delete it.

Give Goose a machine of its own.

Start free on the hosted cloud, or self-host the open source on your own VM.

Try Containarium Cloud How the agent sandbox works