build with a sandbox dev

You do not have to write the code. Add a sandbox, say what you want, and the pixie that lives in it writes the code, runs it, looks at the result and fixes what is wrong.

In this guide you build a small pattern generator, then publish it so any project can use it.

before you start

• A project canvas you can edit.
• Nothing else. The sandbox's own dev pixie is created for you when you add the node.

build it

1. Add a sandbox. Choose Sandbox in the dock's add menu. The node appears with a starter frame, and a pixie appears beside it and moves into the sandbox's workspace. The node's pixie row then shows its name with a sparkle and chat.

2. Describe what you want. Click the pixie row to open its chat and ask in plain words: a seamless tile of my logo in rows and columns, with a colour for each ring and a button that reseeds it. Mention anything it should wire in, such as an image.

3. Watch it work. The pixie reads the current code, makes small edits, saves (a syntax error is caught with its line, and nothing is saved until it passes), then runs the sandbox and looks at the picture. It repeats up to three rounds per deliverable. If it is still short, it stops and says what fell short and what it would try next.

4. Turn the dials. Every setting the pixie exposes appears as a slider, swatch, select or button on the node. It cannot know what you will want to change, so tell it: make the ring spacing adjustable. Hard-coded values you want to tune count as a defect, and it will fix them. For a node with many settings, ask for presets named for the look, such as "warm dusk".

5. Give it assets. The pixie's workspace is a canvas of its own. Open it with the folder icon on the node. There the pixie can generate pictures with model nodes, search the web for real ones, or take ones you drop in, and attach them to the sandbox by name for the code to read. For media that changes each time, ask for an image input instead and wire a picture node in.

6. Edit by hand if you like. The code icon opens the editor with one tab per file. The pixie reads your changes before it edits again, so it never writes over them. Your dial settings and the positions you set in Compose stay yours.

7. Publish to the library. Click the library icon in the node's header and choose Save to library. The sandbox becomes an entry you can find with <kbd>⌘</kbd> <kbd>K</kbd> in any project. Inserting it places a real sandbox node, live and runnable, marked with a violet badge showing its library name.

keep copies in step

Copies made from the library stay linked to their entry:

action	what it does
Push my changes to the library	writes this node's code into the entry for every project
Pull the library's update	shows when the entry changed and has not reached this canvas yet
Open the library entry	opens it as its own canvas
Unlink	keeps the code, stops tracking the library

An amber dot on the badge means the library has an update. Each instance keeps its own settings, output and pixie.

To cut a copy loose, choose Unlink.

what just happened

A sandbox is two things: the node on your canvas, where the code runs and where you tune it, and a private workspace canvas where its dev pixie works. The pixie edits the node remotely through a short list of tools (read, edit, save, run, peek) so it can test its own work the way a developer would. The library entry is a third thing: a shared definition that each instance mirrors.

take it further

• live apps — inputs, preview, pop-out.
• scripts and cloud runs — data-returning scripts and video.
• secrets — let a script call an API.
• derived columns — run the sandbox once per table row.
• meet the pixies