productUpdateMedia doesn't work, no errors thrown

Retired Boards Appdev New Graphql Product Apis
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Topic summary

Problem: productUpdateMedia mutation returned media: null with no errors when trying to update image alt text on a product (even for an image just created via productCreateMedia).

Cause: The mutation was being called with a ProductImage ID instead of a MediaImage ID. ProductImage and MediaImage IDs are different; you cannot construct a valid MediaImage GID by simply changing the type in the GID (e.g., gid://shopify/ProductImage/… → gid://shopify/MediaImage/…).

Fix: Query the product to retrieve the MediaImage ID and use that in productUpdateMedia. Example approach: product { media { nodes { … on MediaImage { id, alt } } } } to obtain the correct MediaImage id, then pass that id to productUpdateMedia to update alt.

Status: Resolved. Screenshots illustrate the null response and the correct MediaImage ID highlighted for reference.

Summarized with AI on December 17. AI used: gpt-5.
1

I have 3 images in a product created with the REST product creation, and I want to update the “alt” property images with the productUpdateMedia mutation, but it doesn’t work. Following the request and the response:

Emanuele_0-1728044800830.png
Emanuele_0-1728044800830.png1002×559 25.9 KB

note the “media : null” in the response.

Curiously, if I try to use the productCreateMedia the operation work fine:

Emanuele_1-1728044900377.png
Emanuele_1-1728044900377.png1183×674 38.2 KB

Then I tried to update, with the productUpdateMedia mutation, this new image created with productCreateMedia, and the operation still doesn’t work.

Have you any idea to solve this problem?

Thank you.

2

It was simple…

The image id variable is a ProductImage id, not a MediaImage id. It’s not possible get the number of the ProductImage and build the MediaImage.

Example

if the image id is 0123456789 I can build the gid product image in this way:
gid://shopify/ProductImage/0123456789

but if I need to refer to the media image I cannot build it like:

gid://shopify/MediaImage/0123456789

The media image will be different, to discover it it is necessary query the product and catch it, like something of the following:

Emanuele_0-1728053273513.png
Emanuele_0-1728053273513.png430×583 5.96 KB

the id hightlighted in red is the MediaImage, this is to be used for productUpdateMedia mutation.