Sandboxd: The Open-Source AI App Builder on Your Own Server

Sandboxd is a self-hosted, open-source AI application builder designed to run entirely on your own infrastructure. It allows users to build applications from simple prompts or run any of 80+ open-source apps, with each application isolated and accessible via its own live URL. The platform emphasizes user control over infrastructure, code, and API keys, operating under an MIT license.

Benefits

Sandboxd offers three primary ways to ship applications. Users can describe an app, and a coding agent builds it within an isolated sandbox, providing an immediate live preview URL. They can also run any of the 80+ supported open-source apps in isolation. The platform gives users full control over their infrastructure, code, and keys without vendor lock-in.

The platform distills complex platform engineering into a single command, offering the following capabilities out of the box. Each user, agent, or branch runs in a private, hardened container. This ensures strict isolation where one entity can never see or break another. Agents access models through a proxy that injects API keys on the wire. No API keys or tokens ever land inside the sandbox workspace, ensuring security.

Users can browse the workspace tree and edit files directly in the browser. Features include syntax highlighting, inline saving, and inline git diffs. Users can review changes file-by-file and ship directly from the console without context switching. The system supports diff, commit, and push operations. Every agent task is checkpointed before execution, allowing users to revert the workspace to its state before a task ran. This eliminates the need for manual git cleanup.

Each app is reachable at a unique, shareable link. The platform handles routing and TLS automatically. Sandboxes sleep when idle and wake upon the next request to optimize costs. The entire setup requires only Docker. There is no need for Kubernetes or separate database management. OpenCode, the platform, runs on a free tier out of the box. This allows a fresh install to build its first app with zero setup. Users can connect their own API key to access the full model catalog.

Use Cases

Sandboxd is designed for users who want to build AI applications without relying on third-party cloud services. It is ideal for developers who need strict isolation between different projects or agents. The platform is useful for teams that require full ownership of their code and infrastructure. It supports integrated Git workflows, making it suitable for developers who want to manage version control directly from the console. The ability to revert tasks makes it perfect for experimental development where mistakes are common. The live preview URLs allow users to share their work instantly with others for feedback.

Pricing

Users can choose how much operational responsibility they wish to retain. The self-host option is free forever. It is MIT-licensed and requires one command to install. Users are responsible for running upgrades. The managed option costs $79 per month. Sandboxd runs on your server in this plan. The provider handles upgrades, tuning, and support. You retain ownership of the infrastructure in this plan. A fully hosted cloud option is coming soon. This option will supply the server as well, requiring no stack management from the user.

Vibes

The platform is designed to be boring on purpose. It relies on standard, reliable technologies. The control plane is a single Go application that orchestrates Docker containers. Traefik handles URL routing. SQLite serves as the source of truth. A security proxy ensures keys never enter the sandbox. A reconciler component converges the Docker state back to the database upon boot. This architecture ensures that the host machine only requires Docker. The system manages the lifecycle of sandboxes, which contain the coding agent and development servers. The web console acts as a pure API client. This turns every app into a workspace where users can chat, edit, review, and roll back changes.

Additional Information

To begin, users can self-host the platform using a single command. The free tier allows for immediate app building without an API key. Sponsors currently fund the maintenance and deployment roadmap for the project.