The contract a step process speaks with the factory: handshake, request, events, result, and environment variables.

Step protocol

The contract a step process speaks with the factory: handshake, request, events, result, and environment variables.

Versions

Newest first. A step may advertise several versions; the factory picks the newest one it accepts.

Version	Status
2	accepted

Handshake. The factory starts the command with KUSAW_HANDSHAKE=1 and the other KUSAW_* names set empty. The step prints one handshake line on stdout and exits.
Request. The factory starts the real attempt. A non-interactive step receives the request JSON on stdin. An interactive step reads it from KUSAW_REQUEST.
Events. While it runs, the step prints one JSON object per stdout line (or appends to KUSAW_EVENTS when interactive).
Result. The last line is a result object (or KUSAW_RESULT when interactive). The factory then waits for the process to exit.

Limit	Duration
Handshake	5s
Kill grace after SIGTERM	10s
Stdout drain after exit	2s
Step deadline	The step's `timeout` key in kusaw.yaml (default 10m).

Outcome	Description
`ok`	The step finished successfully.
`fail`	The step failed.
`retry`	The step asked to be tried again.
`reject`	The step rejected the work.
`skipped`	The step did not run.
`killed`	The factory stopped the step.