Setting up Zotero with WebDav across multiple platforms

If you are looking to fix the Papership WebDav server error that says “Cannot verify server. Please check credentials”, skip to the last section. Or simply, add an empty file named “lastsync.txt” to the root of the <webdav>/zotero directory in the remote WebDav server.

This article shows how to setup Zotero — arguably the best research paper organizing tool — to synchronize papers across iOS, Windows and Ubuntu platforms. Despite some odd issues with external services and clients, I personally find Zotero is the best cross platform tool to synchronize tons of papers.

Setting up Zotero for Desktop

1. Download and install the Zotero client for the corresponding desktop OS.
2. Install the Zotero connector for your preferred browser. It automatically downloads the pdf files directly from web into the Zotero library.
3. Log into the client application with your zotero username and the password.
4. Go to some research paper from the browser (for example, IEEEXplore, ACM). The Zotero connector plugin will now give you the option to add the pdf directly into the library under any subdirectories, if there are any.
5. Now whenever you open and annotate the pdf file from your library, you can click the “sync with Zotero” icon in the desktop client’s top right corner to upload the updated file to the cloud. By doing the same on a different client installed on a different OS platform, you can synchronize the changes with the remote version.

However, by default Zotero file hosting will only give you 300MB of storage. Thus, setting up a WebDav server like Box or pCloud is greatly beneficial in the long run. You can find a list of WebDav links for famous cloud storage services here.

Setting up a WebDav storage

1. Create an account in any cloud storage service that supports WebDav (Box or pcloud typically works great).
2. Add the webdav URL for the cloud service of choice in Zotero->Tools->Preferences as below. Typically the username and the password are the same as your login credentials.
3. In order to setup the webdav, you need to have link both Zotero and WebDav account with the client. In this case Zotero acts as the middleman that store the metadata for the papers, whereas the WebDav service store the actual attachments linked to the metadata.

Setting up Papership for iOS with WebDav

So far Zotero doesn’t have its own client application for iOS devices such as iPad/iPhone (albeit under development). So the option is to install an application called Papership. Although, it has all the nice features for annotating papers, and synchronizing them with Zotero and third party WebDav services, seemingly it is not currently being actively maintained. As it seems like it uses an old zotero protocol to sync the files with the WebDav servers.

1. Install the Papership app on your Apple device.
2. Login with your Zotero credentials and add the WebDav credentials from the settings menu.
3. Click verify server. If it shows success, you are ready to go. However, due to the outdated protocol, it can throw up some 40x code with error “Cannot verify server. Please check credentials” error.

Trick: Add an empty file named “lastsync.txt” to the root of the zotero directory in the webdav server. This will trick the papership to believe that zotero uses this file to memorize the last synchronized file’s timestamp. You can find a lengthy discussion on the issue here.