# Existing File Change Skill

- Treat the latest turn as a requested delta over existing project state.
- Preserve unrelated existing content.
- Do not recreate completed deliverables unless the latest request requires it.
- Do not create a new sibling artifact for an existing-file change unless the latest request explicitly asks for a new artifact or current evidence shows it is connected by the existing project.
- Inspect only when a concrete current fact is needed to choose the target or describe the requested relationship.
- Reuse names observed in current source instead of creating parallel names for existing behavior.
- For changes to an existing target, prefer the active existing-target editor over a creation/full-replacement capability unless replacement is explicitly requested.