OpenAI "Generate a Response" with "file prompt" does not support .docx anymore?

:bullseye: What is your goal?

Generate a structured response in JSON from a DOCX

:thinking: What is the problem & what have you tried?

OpenAI “Generate a Response” with “file prompt” does not support .docx anymore? It was working well till Mars 16 2026 and today, march 19, it fails stating DOCX is not supported anymore.

:clipboard: Error messages or input/output bundles

[400] input: Invalid input: Expected context stuffing file type to be a supported format: .bat, .c, .css, .csv, .doc, .dot, .eml, .h, .htm, .html, .hwp, .hwpx, .js, .json, .ksh, .markdown, .md, .mht, .mhtml, .mjs, .nws, .pdf, .pl, .pot, .ppa, .pps, .ppt, .pwz, .py, .rst, .srt, .svg, .txt, .vcf, .vtt, .wiz, .xlb, .xls, .xml but got .docx.

It’s not just docx, there is some bug on their side.

https://share.google/JMspHqQK1K0f3wq7d