Full bidirectional sync, correct but not yet clever: calendar-query with no time-range, calendar-multiget in batches matched against what was asked for, conditional writes, and per-resource quarantine so one bad task cannot stop a collection. - :caldav gains CalendarCollection (list/fetch/create/update/delete + the three-way 412 triage), ETag with its weak flag, vdirsyncer-style resource names, and the RemoteCalendar seam. - CalDavHttp now sends Accept-Encoding: identity and Prefer: handling=strict, the two headers that keep ETags strong and our bytes unrepaired. - :app gains CollectionSyncer (the reconciliation), SyncEngine, SyncStore, QuarantineStore, SyncReport and a working SyncWorker, plus an in-app sync trigger since ContentResolver.requestSync is gated at our targetSdk. - VTimeZones closes a chunk-1 gap: the mapper emitted TZID with no VTIMEZONE to resolve it, which handling=strict turns from a repair into a rejection. /code-review high raised 11 findings, all fixed. The three that mattered: an empty listing swept the whole list (a VTODO comp-filter some servers mishandle is not proof of deletion, so an empty listing now never sweeps); quarantine never covered creates, so a permanently rejected new task was re-PUT forever; and a RELATED-TO deleted on the server was re-uploaded on the next edit. Reasoning recorded in docs/SYNC-PLAN.md. Chunk 2's on-device review is still outstanding; nothing here has been run on a device or against a real server.
Agendula
A modern Material 3 Expressive task app for Android.
Keeps your tasks on your device, or on top of a tasks provider you already use.
Open standards, no account required.
Agendula is the task-list sibling to Calendula.
Where Calendula is a pure front-end over Android's CalendarContract, Agendula
keeps its own store, designed around RFC 5545's VTODO — the same tasks DAVx5
(and SmoothSync, DecSync, …) sync out of your CalDAV server. It can also read and
write a tasks provider you already have, for anyone already syncing that way.
The name rhymes with its sibling on purpose: Agendula is agenda — Latin for
“things to be done” — given Calendula's -ula ending. Calendula keeps your days;
Agendula keeps your to-dos. (A Calendula flower head is botanically a cluster of
many small florets — so the two apps are florets of one bloom.)
Where your tasks live — your choice
| Where | Sync | Needs | |
|---|---|---|---|
| On your device (default) | Agendula's own database | none yet — CalDAV sync of our own is planned | nothing. No account, no permissions, no other app |
| In a provider you already use | OpenTasks or tasks.org | whatever syncs it for you — DAVx5 and friends | that app installed, and its read/write permission |
Agendula's own store is an ordinary app database — nothing is published to other apps, so there is no authority to clash over and no permission to grant. It coexists with OpenTasks rather than replacing it: installing one never breaks the other, and if you already sync through a provider, that keeps working exactly as it did.
Recurring tasks are expanded per RFC 5545, and everything the schema does not model is round-tripped verbatim rather than dropped — so passing your tasks through Agendula does not quietly lose fields a server sent.
Your tasks are exportable as standard iCalendar .ics files at any time, because
data you can't take with you isn't really yours.
Status: backend complete, UI catching up. Storage, reads and writes, smart-list filtering, a self-scheduled reminder engine, and export are built and unit-tested. The Material 3 Expressive screens are being built on top, one at a time — the storage-mode picker and export screen are not there yet. See
docs/ROADMAP.mdfor status,docs/ARCHITECTURE.mdfor how it's built, anddocs/STORAGE-AND-SYNC.mdfor why storage works the way it does.
Sync sources (by design)
In external-provider mode Agendula works with anything that writes to that provider — DAVx5 (CalDAV), SmoothSync, CalDAV-Sync, DecSync CC, or any Android sync adapter — because it builds on the provider, not on any one sync app. Google Tasks / Microsoft To Do are out of scope by design (proprietary; they would mean owning a sync stack). Open standards — CalDAV / iCalendar / DecSync — are the lane.
Translations
Agendula ships in English so far, and would like not to. Translations are managed on a self-hosted Weblate, and partial ones are fine — an untranslated string simply falls back to English.
No coding needed: register on the Weblate server, pick (or request) a language, and translate the strings in your browser. You can also reach this link in the app from the top of Settings → App language.
License
MIT — see LICENSE.