What is a Toolbox
A toolbox is a container image that provides the development stack: runtimes, package managers, IDEs, and utilities. Application code is not baked into the image — developers clone and manage repos inside the running sandbox. Every toolbox image includes the dev access layer:Build Modes
Build toolbox images from the Images page in the web UI.Scratch
Build an image interactively by selecting components:BYOI (Bring Your Own Image)
Provide an existing OCI image reference. The dev access layer (SSH, code-server, ttyd, gateway) is layered on top automatically.Templates
Templates are pre-built toolbox images available as starting points. Selecting a template skips the base tool installation and only adds your customizations, making builds significantly faster.Supported Runtimes
Image Forking
When a developer installs packages inside a running sandbox, those changes can be detected and captured into a new image via the Fork feature. Fork detection compares the current state against snapshots taken at boot:
Click Fork on a running sandbox to see detected changes and build a new image that includes them.
Build Progress
When you start a build, a modal shows live progress:- Creating — preparing the build
- Building — executing the Dockerfile (installing runtimes, packages, tools)
- Pushing — uploading the image to the registry
- Done — image available for use