The Drive button beside the message box opens Google's own file picker. Before that can happen you have to connect your Google account once, and that connect step is where most failed attachments go wrong: it opens in a popup, and a blocked popup turns it into a full page trip out to Google and back, which lands you on the chat with nothing attached.
Set your browser to allow popups on uni.xyz and the whole thing happens in one press.
What happens when you press it
- If your account is already connected, Google's picker opens immediately.
- If it is not, the connect window opens first. Approve access, and the picker follows.
- Choose one or more files. Cancelling here is silent and attaches nothing, which is correct.
- A chip appears for each file the moment the picker closes, and they import one at a time, in order, showing "Importing from Drive (2 of 3)" as they go.
- When they finish you get a count of how many attached.
Files import individually on purpose. One file that fails, because it is too large or of a type that is not accepted, fails alone and turns its own chip red with the reason. The rest still arrive.
If you came back to the chat and nothing was attached
That is the popup path having been blocked. The connect step fell back to a full page redirect, and you have returned with your account connected but no picker having opened. You will see a message saying Google Drive is connected and asking you to press Attach from Drive again. Do that, and the second press goes straight to the picker.
If instead you see a message saying Drive was not connected, the approval did not complete. Press the button again and approve access at Google.
UNI only ever sees the files you pick
Connecting does not hand over your Drive. Access is granted per file, at the moment you choose it in the picker, and covers nothing else in your account. Files you did not pick are not readable, not listable, and not visible. Revoking access later is done from your Google account's security settings.
What the assistant can do with what arrives
A file imported from Drive is stored against your account exactly like one you dragged in from your computer, and the same limits apply. Images are what the assistant reads directly. For a brief, a spreadsheet or a slide deck, paste the part you want it to work from into your message: attaching a document stores it, but the assistant cannot currently read the text inside one. What you can attach to the assistant has the accepted types, the size cap and the hourly limit.