We are implementing a Checkout UI extension in our existing app, and we need to communicate with our backend. For this communication, we use App Proxy. In general, App Proxy is configured correctly and is working because we use the same request on the order thank you page. At this moment, we want to…

We’ve explored this further and believe the problem is that UI extensions make an HTTP OPTIONS request, which is not supported by App Proxy. The resulting 405 response is interpreted by the browser as a CORS error. For now the solution is to make direct calls to your own app server without App Proxy…

Forgot to mention we have observed that adding “credentials: include” to the fetch call does not include credentials in the “OPTIONS” request. However, we have found that when making a similar request to the Storefront API have all cookies in the request.

Hi @Eltrino , While we don’t currently provide direct support for Functions in this forum, the public [ Shopify/function-examples GitHub repository ] has an active [ discussion board ] that might be worth checking out. Hope you have a great day

Did you get a solution to this issue? Im having the same problem right now. You can bypass by adding a no-cors mode to the fetch but then the response becomes opaque and you cant get the answer haha. Any other solutions?

Having the exact same issue/question…

This is not a Shopify Function from what I can tell - this is a Checkout UI extension

Im not sure how to solve this for POST calls but for GET calls I just made fetch call with no attributes sent through the fetch function and the call passed like normal. For now you could “fake” the POST into a GET call with the parameters through the url as long as there are no sensitive data you a…

Network calls from Checkout UI Extensions do not require proxying through a Shopify endpoint. App Proxy is designed for apps integrating into storefront, rather than checkout. Your app backend will need to specify the Access-Control-Allow-Origin response header to allow the customer’s browser to mak…

Hi @jarthorn , Apologies for any confusion. As I understand it, the App Proxy feature is intended to help us developers conceal the actual URL of our apps, making it appear as if the requests are to the same domain as the shop. Additionally, using the App Proxy provides a kind of authentication bef…

CORS issue with Checkout UI Extension + Fetch API + App Proxy

Retired Boards Appdev Extensions

Happiness April 18, 2023, 8:28am 3

I have the same issue. Will appreciate if anyone can share a solution here.

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CORS issue with Checkout UI Extension + Fetch API + App Proxy

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