Why GPT image API crops original? Please support flexible aspect ratios

No, I don’t think this case exists. As we’ve demoed.

You can always “match” and letterbox.

You upload the image, pad if required (non-square, not 3:2) with white, prompt to include “complete the background” or similar.

Perform your edit, output in most appropriate format (which admittedly will not match your input, but the “sub image” should - see cat example example above.)