Exceptions

Related guidance: reference/exceptions, how-to/troubleshooting.

Runnable examples: preflight.py.

Symbol	Summary
ECNClientError	Base exception for all failures crossing the public client boundary.
ConfigurationError	Raised when client configuration or profile input is invalid.
AuthenticationError	Raised when MQTT credentials cannot be resolved or accepted.
AuthorizationError	Raised when the MQTT broker denies an operation.
ConnectionError	Raised when an MQTT connection or transport operation fails.
TransportBoundaryError	Raised when an endpoint leaves its attested reviewed-network boundary.
ProtocolError	Raised when received MQTT payloads violate the public protocol.
ValidationError	Raised when caller input or decoded public model data is invalid.
TimeoutError	Raised when a bounded client operation exceeds its deadline.
DeliveryError	Report a definite or uncertain mutation delivery phase without implying retry safety.
OutcomeUnknownError	Report a mutation that may have reached the broker or downstream handler.
NotReadyError	Raised when an operation requires a ready, open client or service.
ResourceLimitError	Raised when a configured local or broker resource limit is exceeded.
ClockError	Base error for the optional ECN-relative clock diagnostic.
ClockProtocolError	An NTP response or local timing measurement was unusable.
ClockToleranceError	A valid measurement exceeded a caller-selected absolute offset.