Failure semantics

A failed asset makes its dependent work ineligible, but independent branches can continue. Every planned task reaches a terminal classification.

Terminal outcomes

• success: the attempt completed normally.
• failed: the asset body raised and portable failure metadata was captured.
• skipped: the attempt did not run, commonly because a dependency failed or no partition keys were selected.
• cancelled: a terminal status representable by the result and storage models.

If any task fails, the flow result is failed. Cancellation is distinguished from an asset failure. A dependency-blocked task records its blockers rather than pretending to have executed.

External asyncio cancellation

The current executor does not manufacture a cancelled RunResult when the caller cancels the task awaiting Flow.run_async(). It stops scheduling pending work, requests cancellation of executor-created async tasks, and re-raises asyncio.CancelledError. There is no synthetic terminal result or promised complete terminal event sequence to inspect in that control flow.

The cancelled enum values remain valid model/storage states; their presence does not imply a public cancellation-result API.

Partitioned work

Each selected partition produces one attempt. A failed partition can coexist with successful independent partitions. Inspect attempt results when aggregate task status is not enough.

CLI exit status is a separate layer

A confirmed run that completes with an asset failure exits 1 and still has a structured result. Usage, entry loading, and infrastructure failures use different exit statuses and may not produce a result document. See Exit codes and automation.