With the current TS helpers you have:

    @Prop myProp!: string;
    get myComputedGetter(): string {…
    set myComputedSetter(val: string) {…
    myMethod(in: number): string {…
    @Watch('property') methodToCallOnChange() {…

And a bunch of decorators to connect vuex actions etc.

I assume the Vue3 version will be similar