Follow-up to 227613: Gemini Upload records application/octet-stream; mime_type options empty
Status: Awaiting reply · Asked by FAST Restoration on · 0 views
Hi Pabbly team,
This is a follow-up to my earlier thread, "Gemini Generate Content fails: Drive PDF arrives as application/octet-stream" (thread 227613), which is now closed to replies. We have more test evidence and specific questions.
Workflow (a clone, safe to edit): CLONE - [Recruiter AI Assistant]
https://connect.pabbly.com/v2/app/workflow/mapping/IjU3NjcwNTZiMDYzNjA0M2M1MjY0NTUzMjUxMzAi_pc
I authorize the Pabbly Support team to access my account and make edits if needed.
What we tested on the clone since the earlier thread:
1. A Google Drive download link into the Google AI Studio "Upload File" step: the upload succeeds and the file goes ACTIVE at Gemini, but Gemini records its mimeType as application/octet-stream, and "Generate Content" then fails with 400 "Unsupported MIME type: application/octet-stream".
2. Re-hosting through Pabbly's own File Uploader: the file is served as a .bin download and also reaches Gemini as application/octet-stream, with the same 400 error. So the re-hosting workaround suggested in the earlier thread does not work with Pabbly's own uploader.
3. The Generate step has a mime_type field, but its option list comes back empty in the builder, so we cannot select application/pdf. The Gemini connection ("Hello@FAST") still runs step tests, but its last refresh was 2026-06-14; we are re-authorizing it now in case that is what empties the option list.
Questions:
1. Can the Upload File step be made to register the uploaded file as application/pdf, or does it always take the type from the fetched file's Content-Type?
2. If we set the Generate step's mime_type to application/pdf, does that override the uploaded file's recorded type for file references, or will Generate keep failing while the uploaded file is recorded as application/octet-stream?
3. If neither is possible, please confirm the supported path is an external host that serves Content-Type: application/pdf (we plan to use a Google Cloud Storage signed link) feeding the Upload File step.
Thank you,
Igor, FAST Restoration