Exceptions

python

from rillkit import RillkitError, PublishError, DecodeError, AckMessage, NackMessage, RejectMessage

All inherit from RillkitError, which inherits from Exception.

Exception	Raised by	Meaning
RillkitError		Base class for every RillKit error.
PublishError	broker.publish and publishers	The message could not be written to the stream (Redis error, or a body the codec could not encode). The underlying error is available as __cause__.
DecodeError	codecs, Message.body, pydantic validation	The body could not be decoded or validated. Never retried: the message goes straight to the DLQ.
AckMessage	you, in a handler or middleware	Stops processing and acknowledges the message.
RejectMessage	you, in a handler or middleware	Stops processing and sends the message to the DLQ immediately, skipping retries. The text becomes x-error.
NackMessage	you, in a handler or middleware	Stops processing and nacks the message so it is retried (or dead-lettered once retries run out).

AckMessage, NackMessage and RejectMessage are control flow, not errors. Pass text (NackMessage("rate limited")) so the DLQ x-error field says why; with no text it falls back to the exception class name.

Any other exception from a handler counts as a failure and is handled according to the ack policy.