Connection states

The ConnectionState enum, as reported by ResilientMqttClient.State and streamed by WatchState.

State	Meaning	Leaves via
Disconnected	Initial state, before the first connect	ConnectAsync
Connecting	First connection attempt in progress	success → Connected; failure → WaitingRetry; terminal → Faulted
Connected	A session is live	drop → Reconnecting; DisconnectAsync → Stopped
Reconnecting	The connection was lost; restoring	success → Connected; failure → WaitingRetry
WaitingRetry	Backing off between attempts	timer → Connecting/Reconnecting
Faulted	Terminal failure; sticky	explicit ConnectAsync
Stopped	Stopped at the caller's request	ConnectAsync

Notes:

• Connected is only entered after the lifecycle hook ran (re-subscription) and the offline queue flushed — by the time you observe it, the session is fully restored.
• Faulted and drop transitions carry broker or connection details on ConnectionStateChanged — for example SessionTakenOver after a broker DISCONNECT, or NotAuthorized after a rejected CONNECT.
• Health checks map these as healthy (Connected), degraded (Connecting, Reconnecting, WaitingRetry), and unhealthy (the rest).

ConnectionStateChanged — the WatchState element:

Field	Meaning
Previous / Current	The transition
Attempt	The connection attempt number, for retry telemetry
Reason	The broker's reason code, populated on drops and faults when one is known
ReasonString	MQTT 5 reason string text, when the broker supplied it
ServerReference	MQTT 5 server reference, useful for redirect-aware deployments
Error	The triggering exception for rejected connects, retry failures, disconnects, and terminal faults

ResilientMqttClient.GetDiagnosticsSnapshot() gives the same state as a synchronous snapshot for dashboards and support tools:

Field	Meaning
ClientId, State, Attempt, IsRunning, StateChangedAt	Current lifecycle state
LastReason, LastReasonString, LastServerReference, LastError	Last known broker or fault detail
OfflineQueueDepth, OfflineQueueDroppedCount	Offline queue counters, or null if a custom store cannot report them
SubscriptionCount, PendingSubscribeCount, PendingUnsubscribeCount	Subscription bookkeeping
BrokerCapabilities	Current negotiated broker capabilities while connected; null in disconnected, retrying, stopped, or faulted states