BMAD-METHOD/src/bmm-skills/3-solutioning/bmad-improve-architecture/LANGUAGE.md

Architecture Language

Use these terms exactly.

Terms

Module Anything with an interface and an implementation. A function, class, package, or slice can all be a Module.

Interface Everything a caller must know to use the Module correctly: types, ordering, invariants, error modes, required configuration, and performance expectations.

Implementation The code behind the Interface.

Depth Leverage at the Interface. A deep Module gives callers a lot of behavior behind a small Interface. A shallow Module exposes nearly as much complexity as it hides.

Seam A place where behavior can change without editing in that place. Use Seam, not boundary.

Adapter A concrete thing that satisfies an Interface at a Seam.

Leverage What callers gain from Depth.

Locality What maintainers gain from Depth. Bugs, change, and knowledge stay concentrated in one place.

Rules

• Use Module, not component, service, or unit.
• Use Interface, not API or signature.
• Use Seam, not boundary.
• Use Depth, Leverage, and Locality when explaining why a recommendation matters.

Principles

• The deletion test: if deleting the Module only removes indirection, it was shallow.
• The Interface is the test surface.
• One adapter means a hypothetical Seam. Two adapters mean a real one.