mygame

A starter null0 cart, in WAT.

Press Use this template to make your own, then search the project for mygame and rename it to whatever your game is called.

building

Everything is built inside docker, so you never install wat2wasm yourself. All you need is docker, plus node for the shortcuts below.

npm start

That builds webroot/mygame.null0, serves webroot/, and rebuilds whenever you edit something in cart/. To build once, without the server:

npm run build

Or call docker yourself:

rm -f webroot/mygame.null0
docker run --rm --user $(id -u):$(id -g) -v ./cart:/src -v ./webroot:/out ghcr.io/notnullgames/null0-cart-wat:latest mygame

writing your game

Your code is in cart/main.wat. A cart implements the callbacks it cares about and the host skips the rest:

(func (export "update") ...)

WAT notes

• Raw wasm text - no include mechanism, so copy the imports you need out of null0.wat.
• A Color is a pointer to 4 bytes you write into memory yourself.
• No malloc, so struct-returning functions do not work on the web host.

Run npm run bindings to drop the current null0.wat into cart/ for your editor. It is gitignored on purpose - fetch it again whenever you want, rather than letting a stale copy rot in your repo.

docs

• WAT carts - the whole API, in WAT
• Anatomy of a cart - callbacks, input, distribution
• API reference

publishing

Two workflows come with this template:

• Publish builds the cart and deploys webroot/ to github-pages on every push to main, so anyone can play your game in a browser without installing anything.
• Release attaches mygame.null0 to any github release you create.

Players who want it natively can grab the runtime and run null0 mygame.null0.