sessionKey property
The did:key VID bound to this session by auth/authenticate/0.2, when the producer registered one. Present here so introspection (auth/whoami, auth/sessions/list) can show the binding a client already holds; it is descriptive, not an additional grant — the binding, its scope and its lifetime are governed entirely by the auth/authenticate/0.2 specification that established it. Absent when the session was established without a session key, or by a specification version that does not carry one.
Implementation
final String? sessionKey;