Strawberry GraphQL @ 0.334.0

Released October 11, 2026 at 8:54 PM GMT+00:00

This release adds an error for undecorated subclasses of Strawberry types used in the schema:

import strawberry


@strawberry.type
class Animal:
    name: str


class Dog(Animal):  # missing @strawberry.type
    breed: str


@strawberry.type
class Query:
    dog: Dog


schema = strawberry.Schema(query=Query)

Python inherits the Strawberry definition of Animal , so Dog was silently published as Animal , and its breed field was missing from the schema. The same happened to undecorated subclasses of interfaces and input types: an argument typed with an undecorated subclass of an input type only accepted the parent’s fields, and the resolver received an instance of the subclass that was missing the fields declared on it.

Strawberry now raises an UndecoratedSubclassError pointing at the subclass when it’s used in the schema: in field and argument annotations (including in lists, optionals and unions), lazy types, strawberry.Schema(types=[...]) and as the query, mutation or subscription type.

Schemas that relied on this now fail to build. To fix them, decorate the subclass (with @strawberry.type , or @strawberry.input for input types), or use the parent type in the annotation if you meant to publish it. Resolvers can still return instances of undecorated subclasses of the type they’re annotated with.

This release was contributed by @patrick91 in https://github.com/strawberry-graphql/strawberry/pull/4691