Follow-up to my previous comment:

I see many requests for WebDAV, but I want to highlight why my concern is unique and urgent:

Most users ask for WebDAV for convenience. My request is driven by security necessity.

Currently, the only way to use Proton Drive with essential tools (like Joplin for notes or Home Assistant for backups) is to use unofficial third-party bridges (e.g., proton-webdav-bridge or Rclone scripts).

The Paradox: By forcing users to these workarounds, Proton inadvertently creates a security vulnerability:

Users must trust external, unmaintained code with their credentials.
These tools often decrypt data locally in ways that bypass Proton's zero-access model.
We are pushed away from the secure Proton ecosystem into risky, unofficial territory.
My plea: Please don't just add WebDAV as a "nice-to-have" feature. Add it as a core security requirement to prevent users from having to compromise their safety to use your product. An official implementation closes this loophole and keeps everyone within the trusted Proton environment.

This isn't just about Linux or convenience—it's about maintaining the integrity of our security model.

This is exactly what I've been looking for!
I want to add a critical security perspective: Currently, users who need WebDAV (e.g., for Joplin, Home Assistant, or other tools) are forced to use unofficial bridges like proton-webdav-bridge or Rclone. These workarounds require us to trust third-party software with our credentials or API tokens, which creates a significant security vulnerability and contradicts Proton's zero-access encryption promise.
An official implementation is not just about convenience—it's about closing this security loophole. Please prioritize making WebDAV an official, native feature so we can stay within the trusted Proton ecosystem without resorting to risky external tools.
Thank you for working on this!

Man könnte das ja mit einer Drive Sync Funktion lösen, aber der lokale Ordner ist auf der internen SSD so gut versteckt, dass andere Apps da irgendwie nicht hin kommen. Nur über den Finderbefehl "Gehe zu" kommt man da dran. Wenn der Speicherplatz für den lokalen Proton Drive Ordner frei wählbar wäre, wäre das alles kein Problem mit Backup und Synchronisation.

rclone works with ProtonDrive (confirmed in v1.74.2). rclone supports mount (I haven't tried mounting ProtonDrive, though).

It would be nice if it's implemented via exposing a WebDAV bridge endpoint and register it into the system, since it will automatically enable integration with other applications in the system using the standard XDG file chooser portal (https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.FileChooser.html)

2drop@protonmail.com

Uh, yeah. Like for real man.

I would buy into the 2 terabyte plan if they had linux support, or standards support, like webdav, and let me worry about how.

As it is, I am a Proton VPN customer, but there is 0 incentive for me to upgrade into other tiers without proton support for my storage. I currently have my email hosted in the EU, and I pay them generously every month. Money that could be going to Proton and paying the tab for 2/3'rds of the cost of the 2 terabyte plan.

But seriously, 2 terabyte for lackluster web support from Linux, with the web interface not even having progress bars that work, and Firefox constantly complaining that the window is frozen?

Storage, to be marktetable, has to be reliable. The web interface is just simple NOT reliable. The storage market is highly competitive. Proton has good products, and only needs drive support, and the email client to be out of beta for linux to be highly competitive with other offerings. As it is, I am happy with my Proton VPN working through native linux Wireguard, but without the storage working better, there is no reason to buy anything more than the vpn product.

If they wait too long to jump on this opportunity, customers like me will have moved off to other storage providers, with better storage offerings, and the chance for a monthly recurring revenue (or yearly) will be gone. If the storage prioritizes security over availability, it is not useful. Like many users, give me the raw storage, and I will cook my own encryption solution that fits my needs. I don't need any molly coddling of me, I am capable of encrypting my own data. Thank you very much!

I really like to have WebDAV support for my backups. Currently I am using an other service. In fact the missing WebDAV support is the reason I don't have Proton Duo yet.

I would really like WebDAV support for my GrapheneOS backups, which currently rely in another service.

Please, please, please add WebDAV support.

I have been working with NextCloud and it is fine, but having a cloud provider for real time sync and real encryption, would be a bless.

WebDAV implementation like in Nextcloud would be perfect to sync all my OpenSource services. Joplin, GrapheneOS Backup, Floccus and many more.

Enable WebDAV connections to Proton Drive for backing up data from NAS. Hyperbackup on Synology NAS can use WebDAV to backup NAS data. It should support 2FA to protect the WebDAV connection.

In order to backup.

Support for Webdav.

Can't use rclone with homeassistant to do my automatic daily backups. Already moved everything from Google Drive to Proton Drive, but now it seems I am still stuck to Google Drive. So, please add WebDav.

Am just now learning Proton doesnt have WebDAV support, would love is this could get prioritised

would be nice, but the files will then not be encrypted, so maybe it is possible to add a separate section like "My files", "Computer" and "Photos", i.e. with the name "NOT encrypted". You can only read/write into this folder with WebDAV.
Maybe add a subfolder called "auto-move to drive". Files/Folders uploaded to this unencrypted folder will be automatically moved to the encrypted part of drive after upload is completed.

Since the proton client for rclone is not being maintained (and who can blame them if there isn't a stable public API), this is all the more important.

The lack of WebDAV or a native Linux app is the only reason that I have not switched to Proton Drive for a cloud solution on my home lab.

Thank you for forwarding this issue. Still an App-Password feature or a Proton Drive desktop version for all softwares (Linux, Mac, Windows) is needed so that we can work and save on the cloud simultaneously and safely, without having only safety-doubtable applications to use (like Google's).
I hope that our requests will be met soon. (Sorry, if I made any grammar or syntax mistake.)