sandboxd

sandboxd is a self-hosted, open-source platform designed for building AI applications in isolated environments on a user's own infrastructure. It enables users to prompt a coding agent, which then constructs real applications within private, hardened containers—referred to as sandboxes—that are isolated per user, agent, or branch. Each application is accessible via a live, shareable preview URL with routing and TLS managed by the platform. The system emphasizes user ownership of infrastructure, code, and data, ensuring that sensitive credentials such as API keys are never stored within the workspace; instead, a proxy injects credentials on the wire for agent access.

The platform offers a web-based console that acts as an API client, allowing users to interact with workspaces through chat, code editing, file browsing, and git operations directly in the browser. Features include an in-console code editor with syntax highlighting, inline git diffs, and the ability to save changes or review, commit, and push updates without leaving the console. Each agent task is checkpointed, enabling users to revert the workspace to its prior state without manual cleanup in git. Idle sandboxes automatically sleep and wake upon request, optimizing resource usage and cost control.

sandboxd is delivered as a single-command installation that requires only Docker—there is no need for Kubernetes or a separate database, as it uses SQLite as its source of truth. The architecture comprises a Go-based control plane, Docker for sandbox management, Traefik for URL routing, and a credential-injecting proxy for secure key handling. The platform supports both API and CLI access, and users can choose to self-host or join a waitlist for a managed cloud version. The software is released under the MIT license, offering users full control and no vendor lock-in.

This tool is suited for developers or teams seeking to build, test, and deploy AI-driven applications in isolated, reproducible environments with integrated agent orchestration and live preview capabilities. Its open-source nature and focus on self-hosting make it particularly attractive to those who prioritize infrastructure ownership and security.