There does not appear to be a dedicated field type in Airtable for "meta" data blobs and/or a JSON string.
Is the "Attachment" type my best bet?
I could store it either as a json attachment, or on a String type column.
Since a full json on a text column would likely not be readable, I would store it as attachments.
However, it seems that at least for now, uploading attachments require the file to be already hosted somewhere first, so this route might not be the easiest one:
https://community.airtable.com/t/is-it-possible-to-upload-attachments/188
Right now this isn’t possible with the Airtable API alone. It’s something we’ll think about for future API versions though. A workaround for now is to use a different service (e.g. Filestack90, imgur52, etc.) to process the upload before then sending the url to Airtable. When Airtable processes the attachment, it will copy the file to Airtable’s own (S3) server for safekeeping, so it’s OK if the original uploaded file url is just temporary