Contacts Interaction
The Contacts Interaction app automatically tracks which people a user has recently interacted with and provides this data as a read-only CardDAV address book called Recently contacted. This enables autocomplete suggestions in sharing dialogs, email composition, calendar invitations and other places that query the user's address books — even for people who are not saved as explicit contacts.
The app is shipped with Nextcloud and enabled by default. It can be disabled.
How interactions are tracked
The app listens for ContactInteractedWithEvent events dispatched by other Nextcloud apps. The following apps dispatch this event:
File sharing: When a user creates a share with another local user, an email address or a federated remote user.
Calendar: When a user shares a calendar with another user.
Mail: When a user sends an email.
Any app can integrate by dispatching a ContactInteractedWithEvent with at least one identifier: a Nextcloud user ID, an email address or a federated cloud ID.
When an interaction is recorded, the app first checks whether the contacted person already exists in one of the user's regular address books. If a match is found, no entry is created in the recently contacted address book since the person is already a known contact. Self-interactions (where the user interacts with themselves) are also ignored.
For new contacts, a minimal vCard is generated containing:
FN (display name): Resolved from the Nextcloud user profile if the person is a local user, falling back to the email address or federated cloud ID.
EMAIL: Included when an email address is known.
CLOUD: Included when a federated cloud ID is known.
CATEGORIES: Set to Recently contacted, which allows the Contacts app to identify entries from this address book and offer users the option to copy them to a regular address book.
If the same person is contacted again, the existing entry's timestamp is updated rather than creating a duplicate.
The recently contacted address book
Each user's recently contacted address book is accessible via CardDAV at:
/remote.php/dav/addressbooks/users/{userId}/z-app-generated--contactsinteraction--recent/
The z-app-generated prefix ensures the address book sorts after user-created address books. Users cannot create their own address books with this reserved prefix.
The address book is read-only and not shareable. Users cannot create, modify or delete entries. Entries are only removed automatically by the cleanup job or when a user account is deleted.
The address book is visible in:
CardDAV clients: Any client syncing with the user's Nextcloud (e.g., Thunderbird, macOS Contacts, DAVx5) will see the address book.
Nextcloud Contacts: The address book and its entries appear in the Contacts UI if the Contacts app is enabled. Contacts from this address book can be copied to a regular address book.
Autocomplete: Entries are available for recipient suggestions in sharing dialogs and other places across the Nextcloud web interface.
Data retention
A background job runs every 24 hours and removes entries that have not been updated within the last 7 days. Both the retention period and the cleanup interval are fixed and cannot be configured.
User deletion
When a user account is deleted, all of that user's recently contacted entries are automatically removed from the database.