implement-value-object

Works with Python dataclasses in domain/valueobjects/ and domain/values/ directories. implement-value-object

Create immutable domain value objects using the frozen dataclass pattern with proper validation, factory methods, and immutability guarantees enforced at the type system level.

Since frozen=True prevents normal attribute assignment, use object.setattr() to modify fields during postinit:

Creates immutable domain value objects using frozen dataclass pattern with validation. Use when implementing domain value objects, creating immutable data structures, or adding validation to values. Covers @dataclass(frozen=True), object.__setattr__() pattern in __post_init__, factory methods (from_string, from_dict, from_content), and validation in frozen context. Triggers on "create value object for X", "implement immutable Y value", "add validation to Z value", or "build value object". Source: dawiddutoit/custom-claude.