Calculate/add extra charges during checkout and webhooks for order stages

New Member
2 0 0

Hi folks,

Need some advice - I am new to Shopify development and trying to figure out how I could add extra charges to the order in the checkout process. Use case is tax related, the app will talk to a third party API to calculate any extra taxes needed based on the shopping cart contents and shipping address and these would then be displayed to the customer in the checkout flow.

Related question: Is there a way I can set up a webhook for "order placed" and "payment confirmed" for a particular order?

Reading through the docs but I thought I'd post here to see if I could get some pointers to speed up my exploration.

Thanks in advance.

Replies 2 (2)
Shopify Staff
Shopify Staff
193 35 48

Hey @pandroid ,

Modifying the cart once the user has reached checkout is generally going to be difficult for any standard app. You would need to modify the cart prior to checkout entry, or as part of the checkout creation process.

I can't dive too deep into the specifics as I am not myself a developer, but the most common method of adding custom line items/charges through use of the draft order checkout (which an app could leverage), which can have custom line items, shipping, or tax lines.

Hope this helps!

Graham S | API Support @ Shopify
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Shopify Partner
86 0 21

Hi, is it possible to add tax lines to a draft order? I can't see it in the graphql explorer mutations. How?