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The playground is a split-pane editor where you write Python on the left and see the rendered result on the right. Python executes directly in your browser via Pyodide — no backend required.

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Features

Example selector — Click the “Examples…” button in the toolbar to browse categorized examples from the docs. Type to filter by name or category. JSON mode — Click the { } icon in the toolbar to switch to JSON editing. The editor seeds itself with the compiled JSON from your Python code, letting you tweak the wire format directly. Switching back to Python discards JSON edits (with a confirmation if you’ve made changes). Shareable URLs — The playground encodes your Python code in the URL hash. Copy the URL to share a snippet with someone, or bookmark it to return later. Dark / light mode — Toggle with the sun/moon icon. The editor uses snazzy-light and dark-plus themes to match the docs.

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Running Locally

The playground is bundled with the Prefab CLI: 
pip install prefab-ui
prefab playground
This serves the playground at http://localhost:5174/playground.html and opens your browser. Use --port to pick a different port: 
prefab playground --port 8080

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CLI Reference

prefab playground          # launch the playground
prefab playground -p 8080  # custom port
prefab version             # print the installed version
prefab --help              # show all commands