[How] can one add external CalDAV sources to the Tasks application?

rokejulianlockhart · October 28, 2025, 6:31pm

The basics

Nextcloud Server version?

31.0.10.2 ^[1]
Operating system and version?

Better yet, rpm -qi firefox returns:
```
Version : 144.0
Release : 3.fc42
```
Reverse proxy and version?

⪆ nginx/1.18.0
Installation method?

I utilise a provider: wim.nl.tab.digital.
Are you using CloudFlare, mod_security, or similar?

Not that I see, but I do not know.

Summary of the issue you are facing

I don’t see any way to add an external CalDAV source to enumerate tasks from, like one can in the calendar-app. I want to in order to diagnose:

github.com/tasks/tasks

[Bug] "Expected 207 multi-status, got 200" appears when one attempts to create a list in a Vikunja CalDAV account.

opened 05:50PM - 28 Oct 25 UTC

RokeJulianLockhart

#### How To Reproduce 1. Create credentials at [`app.vikunja.cloud/user/setting…s/caldav`](https://app.vikunja.cloud/user/settings/caldav#app:~:text=API%20Tokens-,CalDAV,-You%20can%20connect). 1. Add a CalDAV account in `org.tasks`: 1. Enter the generated token as the password. 1. Enter the username as the username. 1. Enter the URI, including the appended username, as the URI. 1. Save. 1. Attempt to create a new list in `org.tasks`' GUI. #### The problem A toast renders, [^1] which states: [^4] [^4]: [`linux.codidact.com/posts/294865/history#3`](https://linux.codidact.com/posts/294865/history#3:~:text=Similarly%2C%20acquiring%20diagnostic%20data%20for%20situations%20like%20%5B%60github.com/tasks/tasks/issues/3952%60%5D(https://github.com/tasks/tasks/issues/3952%23issue%2D3562709063)'s%20would%20be%20easier%2C%20because%20%60dumpsys%60%20doesn't%20include%20toast%20information%2C%20due%20to%20its%20ephemerality) <p></p> <img width="1067" height="727" alt="Image" src="https://github.com/user-attachments/assets/03818e5b-4e00-4819-8d88-32b68cfa7a48" /> <p></p> [^1]: [`stackoverflow.com/review/suggested-edits/37030014`](https://stackoverflow.com/review/suggested-edits/37030014#:~:text=It's%20called-,%5Ba%20'Toast'%5D(https://developer.android.com/guide/topics/ui/notifiers/toasts),-%2C%20and%20you) #### Conducted Diagnosis I have uploaded a `.PCAP`of it reproducing, filtered to `org.tasks`, [^3] at [`drive.google.com/drive/folders/1w0SNJsyi3q__h1-5U5SLmmGT_Tq40E3d`](https://drive.google.com/drive/folders/1w0SNJsyi3q__h1-5U5SLmmGT_Tq40E3d?usp=drive_link). You shall need to notify me if you want acces to it. [^2] [^2]: [`bitfireAT/davx5-ose/discussions/1771`](https://github.com/bitfireAT/davx5-ose/discussions/1771#discussion-9055619) [^3]: [`android.stackexchange.com/posts/247052/timeline#comment_356763`](https://android.stackexchange.com/posts/247052/timeline#comment_356763:~:text=in%20the%20PCAPdroid%20main%20screen%2C%20tap%20on%20the%20%22Target%20apps%22%20toggle%2C%20then%20you%20can%20select%20the%20specific%20apps%20to%20monitor) #### My Environment 1. #### Involved Applications <blockquote> ~~~ini sourcePackage=org.tasks versionName=14.8.3 versionCode=140818 ~~~ </blockquote> Additionally, potentially: <blockquote> ~~~ini sourcePackage=at.bitfire.davdroid versionName=4.5.4-ose versionCode=405040005 ~~~ </blockquote> However, the account was added via `org.tasks`' GUI. 1. #### The OS <blockquote> ~~~YAML [ro.build.version.release]: [15] [ro.build.display.id]: [FP5.VT2E.C.059.20250908] ~~~ </blockquote> 1. #### The Device <blockquote> ~~~YAML [ro.product.brand]: [Fairphone] [ro.build.product]: [FP5] ~~~ </blockquote>

…and integrate:

Steps to replicate it

Visit wim.nl.tab.digital/apps/tasks.

wim.nl.tab.digital/status.php, per:

What version of nextcloud am I using?

https://domain.TLD/status.php

↩︎

bb77 · October 29, 2025, 7:30am

Sorry, I’m not sure what you mean by ‘external’ CalDAV sources.

As far as I know, adding external CalDAV sources was never supported in Nextcloud. In Nextcloud, it’s only possible to subscribe to external iCal feeds, which are read-only, and to be honest, I’m not sure if an iCal feed is even capable of serving tasks.

If you are trying to connect Tasks.org to the calendars/task lists provided directly by Nextcloud, I can only tell you that I use DAVx5 on my phone and Tasks.org can use the task lists provided by DAVx5 without any further configuration. I have never tried to connect it directly via CalDAV without DAVx5.

rokejulianlockhart · October 29, 2025, 10:37am

github.com/bitfireAT/davx5-manual’s accounts_collections.rst#what-is-the-base-url may sufficiently elaborate:

github.com/bitfireAT/davx5-manual

accounts_collections.rst

dd4cfd143


========================
Accounts and Collections
========================


What is a DAVx⁵ account?
========================

A DAVx⁵ account represents a connection to a CalDAV/CardDAV service, which can contain address books, calendars and task lists. Most services provide both CalDAV and CardDAV together (technically, this is when both CalDAV and CardDAV can be detected from the same starting point). In this case, you need only one DAVx⁵ account. However, you can also add multiple DAVx⁵ accounts for separate CalDAV/CardDAV services.

Contacts, events and tasks must be saved to a DAVx⁵ account so that DAVx⁵ can synchronize them. **DAVx⁵ will not synchronize or otherwise touch entries that belong to other accounts (like Google or device-local accounts).**

When you add a DAVx⁵ account, you need either an email address or a base URL as the starting point for service discovery. You can find the required base URL in your server manual or ask your IT department. See our `tested services <https://www.davx5.com/tested-with/>`_ for a list of servers/services and how they're used with DAVx⁵.

.. warning:: Always use DAVx⁵ to manage DAVx⁵ accounts. Do not create, delete or otherwise modify DAVx5 accounts manually.

Because `restricted user profiles cannot add accounts <https://developer.android.com/guide/topics/manifest/application-element#requiredAccountType>`_, it is not possible to use DAVx⁵ in a restricted user profile (child profile).

This file has been truncated. show original

@bb77, I have been able to add CalDAV URIs to the NextCloud calendar. However, in retrospect, it might not consume them. I’m surprised that allows me to add them if they’re, from its perspective, invalid.

I’m uncertain, but possess reason to believe that what you describe, or similar, exists:

I am not. I am attempting to add alternative CalDAV sources to the NC server, similiarly to what DAVx⁵ permits, so that I:

…need not configure DAVx⁵ each time I reinstall AOSP (although configuration exportation and importation exists).
…am able to utilise all of my task lists with less competent synchronisers, on i(Pad)OS.

bb77 · October 29, 2025, 11:02am

In this case, we’re really talking about two separate things:

Adding external calendars to the Nextcloud server.
Adding task lists from those calendars to the Tasks.org app.

Regarding the first point, If tasks from those calendars are being displayed, then I suppose that answers my earlier question . But creating new tasks or events in those subscribed calendars isn’t possible, neither in Nextcloud itself nor in any connected apps, because of their read-only nature. Also, I’m not even sure if subscribed calendars are exposed through CalDAV to client apps. As I said, I don’t personally use any.

As for the second point — there are two ways to add CalDAV accounts to Tasks.org: either directly through the CalDAV option in the app (which I haven’t tested), or via DAVx5. I use the latter, and it works perfectly, though I only sync my native Nextcloud calendars and task lists with it.

For the simple reason that calendar subscriptions are read-only, Nextcloud is of limited use for this purpose. The iCal subscription feature is really meant for things like public holiday calendars, organizational event schedules, and similar use cases.

Or in other words, Nextcloud is not suitable as an actual hub for external calendars due to the lack of a true CalDAV client mode. So if you really want/need to work with these external calendars, I wouldn’t do it this way and would add them all to DAVx5 on your phone. And yes, you’ll then have to set it up again on a new phone as well as on your desktop and all other devices you might want to use them.

That’s because iOS already has DAVx5 built in, so to speak. Or, to put it more accurately, iOS includes a CalDAV/CardDAV client at the system level, whereas Android does not. DAVx5 essentially fills that gap by providing the missing functionality on Android.

rokejulianlockhart · October 30, 2025, 3:29pm

@bb77, I’m not discussing the second point; I’m very familiar with davx5-ose ^[1] and tasks, ^[2] and that would be off-topic here for a Vikunja CalDAV source.

Although I should have confirmed this first, I’ve recently created app.vikunja.cloud/tasks/213783:

…which I don’t observe in wim.nl.tab.digital/apps/tasks:

However, I don’t know how to force apps/calendar/listMonth/now to reload on-demand.

iCal isn’t applicable to this, however. They’re incompatible standards.

Darwin’s is a more basic implementation. I significantly prefer being able to choose my CalDAV manager on AOSP.

rokejulianlockhart · October 30, 2025, 3:30pm

@bb77, in which case, I’ve filed a feature request:

github.com/nextcloud/tasks

[Enhancement] Allow ⪆ `31.0.10` to act as a CalDAV client.

opened 03:23PM - 30 Oct 25 UTC

RokeJulianLockhart

enhancement

### Is your feature request related to a problem? Please describe. I've two rel…evant desires: 1. When I add NextCloud as a source in an external synchronisation service — utilise `davx5-ose` as an applicable example — I want external CalDAV sources, added via Tasks' GUI, to be available. 1. I want to be able to access external CalDAV sources in Tasks' GUI. One might consider `davx5-ose` to solve this. However: 1. It requires an external synchronisation service (of which NC and SyncThing are examples) to synchronise its preferences. However, even that basic form of synchronisation requires periodic manual exportation and importation, which is brittle. NextCloud does not suffer from this. 1. It's not available outside of AOSP. 1. Utilising an external client renders NextCloud a purely backend service, which likely isn't what NC desires for its Tasks application. Despite this, I don’t see any way to add an external CalDAV source to enumerate tasks from, like one can for iCal sources in Calendar. (Although Calendar accepts URIs to CalDAV sources, that appears to be erroneous.) ### Describe the solution you'd like Implement a two-way equivalent to Calendar's one-way iCal subscription GUI, but for CalDAv sources. ### Describe alternatives you've considered Utilise an external client, of which `tasks/tasks` is an example, with an external synchronisation service, of which `davx5-ose` is the best example. However, consider its (aforestated) comparative disadvantage. ### Additional context Originally discussed at [`help.nextcloud.com/t/234881/3`](https://help.nextcloud.com/t/how-can-one-add-external-caldav-sources-to-the-tasks-application/234881/3?u=rokejulianlockhart).