Error Handling
Failures are classified, recorded, and either retried or terminated. Executors no longer return OperationFailure effects.
Retryable vs Permanent
An operation handler throws a retryable or permanent error. Retryable failures use backoff and the same idempotency key. Permanent failures fail the command. Exhausted retries become dead letters and can be retried manually as a new attempt.
Saga Compensation
Use saga when completed side effects must unwind in reverse order. Each compensate is a durable operation. Compensation runs once.
Cancellation
cancel is a first-class terminal. It reaches pending work and attached spawned runs. Branch onCancel cleans up losers after race or quorum. Cancellation cannot un-write an external system; compensate explicitly.
Redrive
Redrive re-evaluates a failed or stuck run from current history. It is an audited operator action, not an automatic restart.