What problem does it solve? Domain data in Python often gets shaped as bare primitives, mutable containers, or nullable fields, scattering constraints into runtime checks instead of encoding them in types. This Skill identifies thirteen specific failure patterns in Pydantic value modeling and shows the correct construct for each. ## Core Features & Use Cases - Failure Pattern Catalog: Covers thirteen anti-patterns including bare primitives, unproven scalars, free-floating vocabulary, mutable bags, nullable absence, open models, misbuilt unions, and after-validators. - Corrective Guidance: Each pattern pairs a violating code example with the correct construct, such as frozen RootModel scalars, discriminated unions, and reparameterized field relations. - Use Case: When reviewing a Pydantic model with email: str or settled_at: datetime | None, use this Skill to recognize the anti-pattern and refactor to a constrained RootModel scalar or a Settled/Unsettled union. ## Quick Start Review my Pydantic domain models for value-modeling anti-patterns and show me the correct construct for each violation.
