# Invariant Test Specs
### Scope
- **Purpose**: Document test cases verifying that cli_fmt architectural invariants hold.
- **Responsibility**: Master index for all invariant test spec files in this directory.
- **In Scope**: IN-prefixed spec for Invariant 001 (architectural boundary between cli_fmt and strs_tools).
- **Out of Scope**: Feature behavioral tests — see `tests/docs/feature/`.
### Overview Table
| `001_architectural_boundary.md` | Invariant test spec for Architectural Boundary | ✅ |