OptionalHandleOpaque handle for the run this progress belongs to (e.g. a ProcessRunID).
OptionalMessageHuman-readable progress message.
Stable key of the operation emitting the progress (e.g. RecordProcess.RunNow).
OptionalPayloadArbitrary structured progress payload for richer UIs.
OptionalProcessedItems processed so far, when the operation reports countable progress.
OptionalStatusCoarse status label (e.g. Running, Paused). Operation-defined.
OptionalTotalTotal items to process, when known.
A single progress update emitted by a
LongRunningRemote Operation while it executes. The shape is intentionally generic so any operation can stream meaningful progress.