API

Export	Role
create(spec)	Component spec. render() is required. Extra methods stay on the instance.
render(app, el)	Mount or patch.
hydrate(app, el)	Attach to server HTML.
renderToString(app)	SSR. Runs onBeforeMount, never onMount.
unmountRoot(el)	Destroy the app in el. Safe to call twice.
flushSync(fn?)	Run fn and flush setState now.
html / h / jsx	Same vnode model.
createStore	Synchronous pub/sub. observe on a component unsubscribes on destroy.
version	Installed package version string.
Fragment	JSX fragment.

State: setState replaces the object. Updaters and microtask batching are supported. Development clones plain objects/arrays and freezes them.

Events: DOM names. onDoubleClick → dblclick. Custom onFooBar → "foobar". No synthetic system.

Forms: controlled input / textarea / select (single). Not select multiple.

SSR stores: create a store per app/request. Do not share mutable user data across renderToString calls.