Mypy

Strawberry works with Mypy out of the box thanks to dataclass_transform . No plugin is needed for standard Strawberry types, inputs, interfaces, enums, scalars, or unions.

Pydantic integration

If you use strawberry.experimental.pydantic , add both the pydantic and strawberry plugins to your mypy configuration:

[mypy]
plugins = pydantic.mypy, strawberry.ext.mypy_plugin  

Or in pyproject.toml :

[tool.mypy]
plugins = ["pydantic.mypy", "strawberry.ext.mypy_plugin"]  

The strawberry plugin synthesises __init__ , to_pydantic() and from_pydantic() on pydantic-decorated classes so that mypy can see them.

Enums

The preferred way to register an enum is with the decorator:

from enum import Enum
import strawberry


@strawberry.enum
class IceCreamFlavour(Enum):
    VANILLA = "vanilla"
    STRAWBERRY = "strawberry"  

If you need to expose an existing enum under a different name or alias, use Annotated instead of assigning strawberry.enum(IceCreamFlavour) to a variable — mypy treats the latter as a value, not a type, so it cannot be used in annotations.

from typing import Annotated
import strawberry

MyIceCreamFlavour = Annotated[IceCreamFlavour, strawberry.enum(description="...")]  

MyIceCreamFlavour is a proper type alias that mypy and Pyright accept in annotations.