itchy

Write typed Python games, generate native Scratch blocks, and export self-contained .sb3 projects.

Install with uv and Python 3.12 or newer:

uv tool install itchy
mkdir my-game
cd my-game
itchy init
itchy run

itchy init creates a starter game.py, an SVG costume, and project configuration in an empty directory. Edit game.py to create your game; its comments link to the itchy book. itchy run prepares the Scratch runtime and opens your game in a local browser. The first run needs internet access to install runtime dependencies.

itchy run --no-open       # Serve without opening a browser
itchy run --port 4400     # Choose a port
itchy build               # Export dist/game.sb3 and a shareable browser preview

Open an exported .sb3 in Scratch with File → Load from your computer. Generated projects use standard Scratch blocks; Scratch website import is not yet automatically verified.

For development of itchy itself:

git clone https://github.com/vivainio/itchy.git
cd itchy
uv sync
source .venv/bin/activate
itchy check
itchy test --browser

The book's Markdown sources are in docs/, with navigation and theme in zensical.toml.