GovOPlaN Calendar is the standalone calendar module. It provides tenant calendar collections, iCalendar/VEVENT event storage, a calendar WebUI, and integration boundaries for scheduling, tasks, mail, appointments, workflow, notifications, and external groupware.

Ownership

This repository owns:

backend module manifest calendar
calendar permissions such as calendar:calendar:read, calendar:event:read, calendar:event:write, and calendar:event:export
tenant calendar collections
VEVENT storage with structured query fields plus raw iCalendar property preservation
iCalendar import/export endpoints
calendar WebUI package @govoplan/calendar-webui
/calendar route and navigation contribution

Core owns auth, tenants, RBAC evaluation, database/session primitives, CSRF/API helpers, and shell layout.

Views

The WebUI starts with the standard operational views:

month
week
workweek
day
continuous week-row calendar, where scrolling moves line by line through weeks rather than jumping from one month page to the next

iCalendar model

The first backend implementation stores VEVENT data in two layers:

normalized fields for API range queries and calendar rendering
raw iCalendar property records and generated text/calendar output so unsupported VEVENT properties and parameters can round-trip

CalDAV sync is implemented as a calendar-owned backend primitive. A CalDAV source records the remote collection URL, sync token, ETag/ctag state, username, credential reference, sync interval, sync direction, and conflict policy. Credentials can be supplied transiently for manual sync. Persisted API-managed sources accept only a password or token: Calendar stores an opaque, tenant- and source-bound local reference, backed by the platform secret provider when one is available or by an encrypted calendar-owned credential otherwise. Caller-selected environment and external-provider references are rejected. Trusted deployment code may resolve an env:NAME reference only through the separate deployment configuration helper.

Deleting a source or its calendar immediately scrubs Calendar-owned ciphertext and provider references and emits non-secret audit evidence. If an external secret provider cannot confirm deletion, the operation fails closed without retiring the source or cancelling its queued work; retry is idempotent after a database rollback. Destructive module retirement first deletes and audits all active and legacy retained provider secrets and stops before table removal on provider failure.

Inbound sync uses CalDAV calendar-query for full sync and sync-collection when a sync token exists. It imports all VEVENT components in a resource and soft-deletes local events when remote resources disappear. Two-way sources also write local creates, updates, and deletes back with CalDAV PUT/DELETE and ETag preconditions. If a remote resource changed, the local mutation is rejected and the user must sync before retrying. A calendar-owned task, govoplan_calendar.sync_due_caldav_sources, can run due sources in a worker or cron-style scheduler.

This is not yet a full CalDAV network server. Scheduling inbox/outbox behavior, CalDAV server endpoints, UI credential management, and full user-facing recurrence editing remain follow-up work. The backend now includes a free/busy API primitive for scheduling and appointment modules.

Development

Install through the core environment:

cd /mnt/DATA/git/govoplan-core
./.venv/bin/python -m pip install -r requirements-dev.txt

Run the WebUI from the core host:

cd /mnt/DATA/git/govoplan-core/webui
PATH=/home/zemion/.nvm/versions/node/v22.22.3/bin:$PATH /home/zemion/.nvm/versions/node/v22.22.3/bin/npm run dev

Module integration

Backend entry point:

[project.entry-points."govoplan.modules"]
calendar = "govoplan_calendar.backend.manifest:get_manifest"

Frontend package:

@govoplan/calendar-webui

The integration concept is maintained in docs/CALENDAR_INTEGRATION_CONCEPT.md.