Sync Architecture · Auto-Discovery

Cloudron Packaged CalDAV: .well-known/caldav & DNS SRV Principal Auto-Discovery on iPhone & iPad

Technical runbook for Cloudron Packaged CalDAV (Containerized Multi-App CalDAV) focusing on .well-known/caldav & DNS SRV Principal Auto-Discovery in Cloud Calendars for iOS & iPadOS.

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Direct device-to-provider sync with zero cloud relay servers, live Apple WeatherKit hourly overlays, and interactive iOS 18 widgets.

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1. Protocol Handshake & Principal Topology (Containerized Multi-App CalDAV)

When connecting Cloudron Packaged CalDAV via Containerized Multi-App CalDAV to an iPhone or iPad, reliable calendar rendering depends on how the client negotiates collection discovery, recurrence expansion, and incremental change tokens. Cloud Calendars operates directly over native iOS EventKit and standard WebDAV/CalDAV/ActiveSync transports without routing credentials through a third-party cloud proxy.

ParameterCloudron Packaged CalDAV SpecificationCloud Calendars Handling
Transport ProtocolContainerized Multi-App CalDAV over TLS 1.2/1.3Direct device-to-endpoint socket (0 relay hops)
Engineering Focus.well-known/caldav & DNS SRV Principal Auto-DiscoveryDeterministic local SQLite cache + atomic UI diffing
Recurrence & ExceptionsRFC 5545 RRULE, EXDATE, RECURRENCE-IDFull local expansion across Single-Day, Multi-Day & Month views
Timezone ResolutionIANA Olson ID + embedded VTIMEZONEAutomatic DST boundary clamping & floating-time support
Conflict DetectionCross-account Free/Busy overlap checkInstant visual overlap bars across all active accounts

2. Step-by-Step Configuration & Diagnostics on iOS 18 / iPadOS 18

Step 1: Provision Endpoint & Auth

Authenticate your Cloudron Packaged CalDAV account using OAuth 2.0 PKCE, MDM managed profile, or a dedicated app-specific password. Verify that the principal URL resolves your primary and delegated calendar collections.

Step 2: Validate Auto-Discovery

Open Cloud Calendars and inspect the Multi-Calendar visibility drawer. Assign a high-contrast color token to each collection from Cloudron Packaged CalDAV so overlapping commitments stand out immediately.

Step 3: Bind Widgets & Alerts

Pin the iOS 18 Home Screen or Lock Screen widget to monitor upcoming events from Cloudron Packaged CalDAV alongside live Apple WeatherKit hourly telemetry.

3. Production Edge Cases & Remediation

In enterprise and self-hosted deployments of Cloudron Packaged CalDAV, the most frequent synchronization anomalies stem from orphaned recurring instances (where an organizer modifies a single occurrence of a series) or mismatched CTag/sync-token responses behind reverse proxies. Cloud Calendars reconciles modified master series and detached exceptions cleanly while preserving your local alert offsets.

Visual Workspace & Live WeatherKit Overlay

Cloud Calendars Full-Screen iPadOS Multi-Column Workspace
Cloud Calendars Full-Screen iPadOS Multi-Column Workspace
Cloud Calendars Readable Month View Showing Full Event Titles & Color Bars
Cloud Calendars Readable Month View Showing Full Event Titles & Color Bars

Frequently Asked Technical Questions

Does Cloud Calendars relay Cloudron Packaged CalDAV credentials through an external server?

No. Your Cloudron Packaged CalDAV credentials and calendar payloads remain strictly between your iOS/iPadOS device and your Containerized Multi-App CalDAV server.

How does Cloud Calendars handle .well-known/caldav & DNS SRV Principal Auto-Discovery for Cloudron Packaged CalDAV?

It evaluates RFC 5545 rules, VTIMEZONE definitions, and incremental sync tokens locally on device so multi-day and month views update instantaneously.

Ready to deploy a zero-relay multi-account calendar on iOS & iPadOS?

Install Cloud Calendars: Sync & Widget (App Store ID 6744690319) and connect your accounts in under 60 seconds.

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