Pydantic Integration

AutoRegistry provides a drop-in replacement for pydantic's pydantic.BaseModel class.

Basic Usage

from autoregistry.pydantic import BaseModel


class Pokemon(BaseModel):
    health: int


class Pikachu(Pokemon):
    health: int = 100


class Charmander(Pokemon):
    health: int = 90

This gives you both AutoRegistry and Pydantic features:

>>> # AutoRegistry features work at the CLASS level
>>> list(Pokemon)
['pikachu', 'charmander']
>>> Pokemon["pikachu"]
<class '__main__.Pikachu'>

>>> # Pydantic features work at the INSTANCE level
>>> pikachu = Pikachu()
>>> pikachu.model_dump()
{'health': 100}
>>> pikachu.health
100

Configuration Options

All of AutoRegistry's configuration options work with Pydantic models:

from autoregistry.pydantic import BaseModel


class Fruit(BaseModel, snake_case=True):
    color: str


class RedApple(Fruit):
    color: str = "red"


class GreenApple(Fruit):
    color: str = "green"

>>> # snake_case converts RedApple -> red_apple
>>> list(Fruit)
['red_apple', 'green_apple']

See Configuration for all available options.

How it Works

The integration uses multiple inheritance and a custom metaclass:

from pydantic import BaseModel as PydanticBaseModel
from autoregistry import Registry
from autoregistry.pydantic import PydanticRegistryMeta


class BaseModel(PydanticBaseModel, Registry, metaclass=PydanticRegistryMeta, base=True):
    """Base class combining Pydantic's BaseModel with AutoRegistry."""

The PydanticRegistryMeta metaclass merges both Pydantic's and AutoRegistry's metaclasses, ensuring registry dict-like methods (like keys(), items()) operate at the class level while Pydantic's validation works at the instance level.

The base=True parameter marks this as a base registry class, so subclasses will not be registered to BaseModel itself (see base for details).

This is actually how autoregistry.pydantic.BaseModel is exactly defined (no body!). All logic is within PydanticRegistryMeta; autoregistry.pydantic.BaseModel only responsibility is to combine these class/metaclass definitions so that inheritance is correct.