Sveltekit solution with typescript

First time using typescript, i still don't know which one should i give a type. like, should i create an interface for an array which used for localStorage and svelte store. And this is what i do, is there any tips on how to build a localStorage with svelte store and typescript?

import { writable } from 'svelte/store';

const storedLinks =
JSON.parse(localStorage.getItem('linkStorage') || 'null') || [];

export const links = writable<string[]>(storedLinks);

links.subscribe((value) => (localStorage.linkStorage = JSON.stringify(value)));