Cart API Frequently Used - Vanilla JS

cart_api.js

// Always compare to the docs first: https://shopify.dev/docs/api/ajax/reference/cart

// Get the Cart
fetch("/cart.js")
  .then((response) => response.json())
  .then((data) => console.log(data));

// Add to Cart
let addToCartItem = {
  items: [
    {
      id: varID,
      quantity: 1,
      properties: {
        'Cart line item property': 'Standard',
        '__Cart line item property': 'Hidden' // item is hidden due to prefacing with double underscore
      }
    }
  ]
}

async function addToCart(){ 
  let response = await fetch(`/cart/add.js`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(addToCartItem)
  })
  if(!response.ok) {
    throw new Error(`Something is up! Status: ${response.status}`);
  }
  else {
    console.log(`${addToCartItem} added to the cart`;
  }
}