How can I resolve the 'bucketUrl took too long to respond' error in my CLI 3.0 app on S3 AWS?

Shopify Apps

Topic summary

Main issue: After deploying a Shopify CLI 3.0 app’s front-end build to a public AWS S3 bucket and updating the app settings to use that bucket URL, the app fails to start in a Shopify store with the error: “The bucketUrl took too long to respond.”

Recent context: The build runs correctly locally. OAuth (authorization flow) is handled by a local backend, while the front-end is intended to be served from S3.

Steps taken: Uploaded the build to S3, set the bucket to public, and changed application setup to point to the S3 bucket URL.

Clarifications: Shopify CLI 3.0 is Shopify’s app development tool; AWS S3 hosts static assets; OAuth manages secure user authorization.

Status: The author is seeking suggestions to make the front-end run from S3. No solution or decisions yet; discussion remains open.

Summarized with AI on February 9. AI used: gpt-5.
1

I’m developing an application using the Shopify CLI 3.0, after testing everything works correctly if I run the application build locally. However, when I uploaded the build to an s3 Bucket and configured s3 as public, and change the settings in the application setup, I got some issues starting the application in a Shopify store. The OAuth process is controlled by a local backend. Any suggestion that can help me to make the front-end run? Thank you very much.

The error is this: “The bucketUrl took too long to respond”