CardDAV-Sync is a CardDAV client for Android to synchronize contacts. Due to its implementation as sync adapter it integrates seamlessly with the default contacts app. (Also looking for CalDAV-Sync?)

There is a wiki where users can share their experiences and tips for certain servers at dmfswiki. Please feel free to join and contribute.

There are two versions at the market, a paid one and a free one. The following features are available in the paid version only:

• sync websites
• sync organizations, title and position
• sync notes
• sync anniversaries
• sync nicknames
• sync instant messengers
• sync categories (mapped to groups in Android)
• sync phonetic names
• sync relations

Please uninstall the free version before you install the paid one (and vice versa).

Features (version 0.4.5):

• Sync contacts with a CardDAV-server (tested and reported to work with DAViCal, SOGo, Zimbra, egroupware, Darwin CalendarServer and more, see the list of supported servers & services for detailed information)
• basic support for self-signed certificates (no client certificate authentication)
• two-way-sync (although no data loss has been reported so far: please, don't forget to backup your contacts before you use this! It is still beta!)
• syncs names, phone numbers, email addresses, postal addresses, photos and birthdays (please see date format)
• one way sync of Apple-style groups
• basic periodic syncing (it doesn't make up for syncs missed due to insufficient connectivity)
• automatic address book discovery (works with most servers in standard configuration)

It is still under development and some important features may be missing. Known limitations are:

• only "server wins" and "phone wins" (default) conflict resolution available (that is when a contact is updated on server and on phone between two syncs)

Approved by Silent Circle

CardDAV-Sync has been approved by Silent Circle and is available in the Silent Store on Blackphone devices.