AToCal — Add To Calendar

A Nextcloud app that lets remote applications create events in the authenticated user's Nextcloud Calendar via a simple link.

How it works

remote app                  Nextcloud (atocal)
    |                              |
    |  GET /apps/atocal/confirm    |
    |  summary, start, end, ...    |
    |----------------------------->|
    |                              |  confirm page
    |<-----------------------------|
    |                              |
    |  POST /apps/atocal/create    |  (CSRF token from form)
    |----------------------------->|
    |                              |  event in "Personal" calendar
    |<-----------------------------|  redirect to Calendar app

The remote app links the user to the confirm page. The user reviews the event and submits the form. The event lands in the user's "Personal" calendar and the browser opens the Calendar app.

Routes

Method	Path	Purpose
GET	/apps/atocal/confirm	Show confirmation page
POST	/apps/atocal/create	Create the event

Link parameters (GET /confirm and form POST /create)

Parameter	Required	Rules
summary	yes	max 255 chars
start	yes	datetime-local, e.g. 2026-10-07T14:15
end	yes	after start, same format
description	no	max 10000 chars
location	no	HTTPS URL
url	no	HTTPS URL; merged into description
organizer	no	email address

Dates carry no timezone and are interpreted in the user's Nextcloud timezone (server default as fallback).

Reminder

Every created event gets a display alarm 15 minutes before it starts (TRIGGER:-PT15M VALARM). The reminder is not configurable.

Example:

https://cloud.example.com/apps/atocal/confirm?summary=Kickoff&start=2026-10-12T10:00&end=2026-10-12T11:00&location=https%3A%2F%2Fmeet.example.com%2Fkickoff

Requirements

• Nextcloud 34 or 35
• Calendar app enabled
• A writable calendar named "Personal" (event creation fails with a friendly error otherwise)

Install

Copy this directory to the Nextcloud server as custom_apps/atocal, then:

occ app:enable atocal

Structure

appinfo/info.xml          app metadata
appinfo/routes.php        routes
lib/AppInfo/Application.php   container setup
lib/Controller/CalendarController.php   confirm/create logic
templates/confirm.php    confirmation page
templates/style.css       page styles