Unique identifier of the topic. This number may have more than 32 significant bits and some programming languages may have difficulty/silent defects in interpreting it. But it has at most 52 significant bits, so a 64-bit integer or double-precision float type are safe for storing this identifier.
OptionaluserOptional. Information about the user that created the topic. Currently, it is always present
Describes a topic of a direct messages chat.