kp-structured-concurrency

One-line summary

Nest coroutines under explicit scopes whose lifetimes form a tree — making cancellation, failure propagation, and resource cleanup predictable and automatic.

When to use this skill

• Multiple concurrent operations need to coordinate: combine results, propagate cancellation, or isolate failures.
• A function spawns child coroutines and must not return until all children complete.
• Sibling failure should NOT cancel its siblings (use supervisorScope).
• Sibling failure SHOULD cancel its siblings ("fail fast"; use coroutineScope).

When NOT to use this skill

• A single suspend call to a single suspend function — no concurrency to structure.
• Truly independent fire-and-forget work whose failure has no consequence for the rest of the program — though even then, scoping is usually worth it.

Core content

coroutineScope { … } — fail-fast group. Runs its block within a new scope as a child of the calling scope. Suspends until all children complete. If any child fails, the rest are cancelled and the failure rethrows to the caller.