With Zotra, you can get a bibliography entry from a url or a search identifier (DOI, ISBN, PMID, arXiv ID). You can even add a bookmark to you browser so that when you click it, the bibliography information of the webpage you’re visiting would be saved in some bib file. You can also get the links for attachments and download them from Emacs.

This is done using Zotero translators, so it basically has the full power of Zotero. There is no need for the Zotero client, but it needs to connect to either Zotero translation server or zotra-cli as the backend.