Lean 4 Principle Check

Use the repo's existing Lean 4 model to check whether a planned design conflicts with encoded principles before product implementation begins.

Preconditions

Start from a concrete plan. If there is no plan, run /plan-it first.

Use existing Lean 4 artifacts or an explicit user request to create one. Do not introduce Lean 4 to an unrelated project as incidental cleanup.

Treat Lean as a formal design gate, not as a replacement for product tests. After this check passes, continue with /implement-plan; use /tdd only when test-first was selected.

Process

1. Locate the Lean Boundary

Find the Lean workflow before editing: