How do I create/attach a File Field to an existing item using the 1Password CLI

Hi oliverroos, you're correct that it is not supported to attach file fields to document type items via the CLI at this time.

Document type items are currently only supported in the separate op document create command and adding file fields is only supported in op item create.

I'll file a feature request to add support for attaching file fields to Document type items via the CLI as well. Probably easiest to merge op document create and op item create (and similarly for edit).

In the meantime, here's an example how you can attach file fields to any other type of item:

echo "Hello from Simon" > hello.txt && op item create --title "Greeting" --category SecureNote "greeting[file]=hello.txt" && rm hello.txt