id: oe.lab.compose-sandcastle-request
title: Compose a Sandcastle request
level: intermediate
duration: 45m
prerequisites:
  - oe.lab.hello-world-pico-sandcastle
  - oe.course.crossplane
teaches:
  - Compose → construct boundary
  - Crossplane requests engineering work (XR → EngineeringTask)
  - Sandcastle consumes an EngineeringTask, not an XR
  - Parametric construction (request value → durable artifact)
  - Artifact boundary preserved across compose → construct
produces:
  - compose-sandcastle-request-branch
  - compose-sandcastle-request-engineering-task
referenced_by:
  - oe.course.sandcastle
  - oe.lesson.sandcastle.02-composing-a-sandcastle-request