Sandboxd

Early development

Sandboxd is new and changing fast. There are no releases yet; follow along on GitHub.

Overview

Sandboxd runs disposable container sandboxes on machines you manage, with a terminal and port forwarding in the browser. The idea is to hand a repository and a prompt to a coding agent, or spin up a notebook, an editor or a preview environment, and keep watching and controlling it from a web page, with no setup on the client side.

It started as a piece of Dev Agents, which needed a safe, disposable place to run agents, and grew into a project of its own.

Each sandbox is a single container running one command in a PTY. It goes away when the command exits, when it sits idle for too long, or when you delete it.

• sandboxd-api: the control plane. Keeps sandbox state and serves the terminals and previews.
• sandboxd-worker: a small daemon on each machine. It dials out to the control plane, so machines need no open inbound ports.
• Reference UI: a client that shows what the API can do.

Both daemons are static Go binaries. The repo ships Nix packages and NixOS modules, OpenTofu for infrastructure, Traefik for ingress, and a TypeScript SDK generated from the OpenAPI spec.