Configuration
- Completion key — string, supports
{assign_key}interpolation (same syntax as Flow Log). Use the same template as the upstream Completion Guard.
Tips
- Idempotent — running twice for the same key does nothing the second time.
- Place this node after the work that should be guarded. If any upstream node fails or skips the branch, this writer never runs and no marker is recorded.
- Leaving the key blank logs a warning and no-ops.