Bulk change Titles based on existing fields

[beardedfool]

Assuming I'd like to create a title for some, but not all, documents based on other fields, if there a way to bulk change these
e.g. {created_year-{created_month}{correspondent}{document_type}

I can see I could export everything, chaning PAPERLESS_FILENAME_FORMAT and then reimport but it there an easier way? Perhaps through the API?