The Annotated type is worth mentioning as well. Today in something like SQLModel you do (from the readme): class Hero(SQLModel, table=True): id: Op

The Annotated type is worth mentioning as well. Today in something like SQLModel you do (from the readme): class Hero(SQLModel, table=True): id: Optional[int] = Field(default=None, primary_key=True) And that's fine. I wouldn't necessarily change anything here. Annotated gives you the option of approaching things in a different way, though. class Hero(SQLModel, table=True): id: PrimaryKey[Optional[int]] = None I have some use cases where the alternative approach is useful, like quantification of class fields or function arguments.