PTLam FastAPI Code Style

Rules for the FastAPI boundary of a Python service: four-layer feature packages, application composition and lifespan, HTTP contracts, dependencies, use cases, persistence registration, concurrency, errors, observability, and API tests. This skill owns FastAPI mechanics only; Python and the foundation own everything underneath.

Required skills

ptlam-code-style-python

Reason: Provides the Python language, data-model, concurrency, exception, and pytest mechanics underneath the FastAPI boundary.