Building a CardDAV client

Step-by-step guide to building a CardDAV client.

1. Discovery

Try /.well-known/carddav on the user’s domain. Follow redirects.

2. Principal

PROPFIND for current-user-principal.

3. Home Set

PROPFIND the principal for addressbook-home-set.

4. List Address Books

PROPFIND the home set to discover address books.

5. Query Contacts

Use addressbook-query REPORT with filters:

<C:filter>
  <C:prop-filter name="EMAIL">
    <C:text-match match-type="contains">example</C:text-match>
  </C:prop-filter>
</C:filter>

6. Create/Update Contacts

PUT a vCard resource to the address book collection.

7. Sync

Use sync-collection REPORT for incremental updates.