admin api error: "Not Found" when doing PUT on Assests api

Shopify Apps

Topic summary

A developer is encountering a “Not Found” error when attempting to use Shopify’s Assets API via a Ruby backend app.

Technical Details:

  • The error occurs specifically on the asset.save! method call during a PUT request to the Assets API
  • Error includes reference ID: c6a88d0d-0099-4bf7-8df5-b997
  • The developer is using a theme ID obtained from one of their installed themes

Current Status:

  • The developer is testing basic Assets API endpoint functionality using examples from Shopify’s official documentation
  • They believe the theme ID itself is not the source of the error
  • The issue remains unresolved with no clear cause identified
Summarized with AI on November 7. AI used: claude-sonnet-4-5-20250929.
1

I’m developing a shopify app, with a ruby backend, and trying to call the assets api.
Here is the code snippet :

Screenshot 2024-08-08 at 2.30.37 PM.png
Screenshot 2024-08-08 at 2.30.37 PM.png1280×374 43.1 KB

The line of code containing “asset.save!”, causes an error that looks like this:

{“errors”:“Not Found”,“error_reference”:“If you report this error, please include this id: c6a88d0d-0099-4bf7-8df5-b99731903721-1723148803.”}

I have got that theme id from one of my installed themes, so I don’t think that is causing the error.
I am just trying to test the assets api endpoint functionality using one of the examples from here: https://shopify.dev/docs/api/admin-rest/2024-07/resources/asset#put-themes-theme-id-assets