An error edge routes a failure instead of raising it

What it means

A failing step whose failure has somewhere to go does not raise it: the run continues down the error wire instead, carrying a payload built for that purpose rather than the step's own output. The step is still recorded as having failed — routing a failure is not the same outcome as the step succeeding — but that failure is marked as having been routed, so a resume does not treat it as the kind of failure that stops the run.

Example

A step named boom fails, and carries one outgoing wire from its error output:

{ "source": "boom", "source_handle": "boom-output-error", "target": "handler", "target_handle": "handler-input-input" }

"boom blew up"

The payload's node_id is boom; the step's job is recorded as failed and marked as routed, never as completed.

Without that wire, the same failure is never routed: it stops the run instead.