Calls with this contact across every line on the account, both directions.
ISO-8601: when the most recent message or call happened. The list is ordered by
this, newest first, and it is the startingAfter cursor for the next page.
The most recent message's text, for a preview line. Empty for a call, for a
media-only message, and for one data retention has cleared — lastKind,
lastMediaCount and lastRedacted tell those three apart.
The most recent call's duration in seconds, or null when the most recent interaction was a message. 0 is a real duration — a call that never connected.
Which of lastBody / lastCallDuration carries anything.
Attachments on the most recent message; 0 for a call or a text-only message.
True when data retention cleared the most recent message's content.
One-to-one messages with this contact across EVERY line on the account, both directions. Group messages are excluded.
The contact's number, E.164. Pass it as contact to DialClient.listMessages.
One phone number the account's lines have talked to.
Derived from message and call history rather than stored: there is no address book to add anyone to, so a contact has no id and the number is its identity.