Shopify API get cart from external site

Question

I am creating a custom checkout page for my Shopify store in order to handle custom integrations with stripe and my own API. I'm able to send data from the Shopify cart.js API to my custom checkout through query params, but this string is rather ugly and very long. There is some concern over whether this will cause problems, or if there is a better way.

For reference, here's the default cart json encoded into a query string. Yowza!

/?cart=%7B%22token%22%3A%22f57b4a11a31e5daaa3fae1c4cfcb0676%22%2C%22note%22%3Anull%2C%22attributes%22%3A%7B%7D%2C%22original_total_price%22%3A119495%2C%22total_price%22%3A119495%2C%22total_discount%22%3A0%2C%22total_weight%22%3A9072%2C%22item_count%22%3A3%2C%22items%22%3A%5B%7B%22id%22%3A22480473539%2C%22properties%22%3Anull%2C%22quantity%22%3A2%2C%22variant_id%22%3A22480473539%2C%22key%22%3A%2222480473539%3Adf55503d6a89267ddc2b2d67afcc9bac%22%2C%22title%22%3A%22White%22%2C%22price%22%3A59500%2C%22original_price%22%3A59500%2C%22discounted_price%22%3A59500%2C%22line_price%22%3A119000%2C%22original_line_price%22%3A119000%2C%22total_discount%22%3A0%2C%22discounts%22%3A%5B%5D%2C%22sku%22%3A%220002%22%2C%22grams%22%3A4536%2C%22vendor%22%3A%22Meural%22%2C%22product_id%22%3A7214792579%2C%22gift_card%22%3Afalse%2C%22url%22%3A%22%2Fproducts%2Fwhite%3Fvariant%3D22480473539%22%2C%22image%22%3A%22https%3A%2F%2Fcdn.shopify.com%2Fs%2Ffiles%2F1%2F1348%2F6411%2Fproducts%2Fwhite-front.png%3Fv%3D1468709138%22%2C%22handle%22%3A%22white%22%2C%22requires_shipping%22%3Atrue%2C%22product_type%22%3A%22%22%2C%22product_title%22%3A%22White%22%2C%22product_description%22%3A%22%5CnIncludes%20free%20white%C2%A0power%20cable.%C2%A0%5CnDimensions%3A%2032in%20x%2021in%20x%201.5in%22%2C%22variant_title%22%3Anull%2C%22variant_options%22%3A%5B%22Default%20Title%22%5D%7D%2C%7B%22id%22%3A284391014424%2C%22properties%22%3Anull%2C%22quantity%22%3A1%2C%22variant_id%22%3A284391014424%2C%22key%22%3A%22284391014424%3A0d9cdd833041859ad41f895bf59cb17a%22%2C%22title%22%3A%22Meural%20Membership%22%2C%22price%22%3A%22%244.95%2Fmo%22%2C%22original_price%22%3A495%2C%22discounted_price%22%3A495%2C%22line_price%22%3A495%2C%22original_line_price%22%3A495%2C%22total_discount%22%3A0%2C%22discounts%22%3A%5B%5D%2C%22sku%22%3A%22%22%2C%22grams%22%3A0%2C%22vendor%22%3A%22Meural%22%2C%22product_id%22%3A52034633752%2C%22gift_card%22%3Afalse%2C%22url%22%3A%22%2Fproducts%2Fsubscription%3Fvariant%3D284391014424%22%2C%22image%22%3A%22https%3A%2F%2Fcdn.shopify.com%2Fs%2Ffiles%2F1%2F1348%2F6411%2Fproducts%2Fcollage.jpg%3Fv%3D1503795405%22%2C%22handle%22%3A%22subscription%22%2C%22requires_shipping%22%3Afalse%2C%22product_type%22%3A%22subscription%22%2C%22product_title%22%3A%22Meural%20Membership%22%2C%22product_description%22%3A%22%22%2C%22variant_title%22%3Anull%2C%22variant_options%22%3A%5B%22Default%20Title%22%5D%7D%5D%2C%22requires_shipping%22%3Atrue%7D

I'll obviously try to trim this down if necessary, but it's not ideal. As far as I understand it, there is no way to get the Shopify cart through an API from an external website (which seems a little silly, but oh well). Does anyone know a better way?

Answer 1

I discovered that you can easily pull cart data from an external site using the same ajax request that you would internally. Here's how to use it. It doesn't work if user isn't allowing cookies, so isn't perfect, but works well for now.

Answer 2

I think this should be your flow to access cart data to your custom checkout page.

1. Maintain cart webhook. Keep data of cart of your store in some database.
2. You need to use cart token and session as point of communication and authentication between shopify and your custom checkout.
3. Put a customized button(ex. My Checkout) on shopify cart page to proceed for your custom checkout option.
4. On the click of your customized button get the cart token to your custom checkout page and retrieve the cart data using it. You can use session for authentication.
5. After retrieving the particulate cart data, you can do necessary manipulation in your checkout page.