Decorators and metadata

Class decorators

Type, Input, Interface, Query, Mutation, and Subscription accept a class directly or can be called with metadata. Their shared options include GraphQL name, description, directives, and explicit field configuration where applicable.

@Type
class User: ...


@Type(name="Account", description="A billable account.")
class AccountModel: ...

Enum, Union, and Scalar use definitions appropriate to their GraphQL kind but register into the same type registry and compile into the same schema model.

Field

Field works as an annotated attribute descriptor, method decorator, or callable resolver declaration. Supported metadata includes:

name, description, deprecated or deprecation_reason
type or type_ for explicit GraphQL type control
default or default_factory
arguments, directives, extensions, and permission_classes

Arguments

Use Arg(...) as a parameter default or Argument(...) with typing.Annotated. Argument metadata supports names, descriptions, deprecation, defaults, and directives.

from typing import Annotated

from fastql import Argument, Field


@Field
def user(self, id: Annotated[str, Argument(description="User identifier")]) -> User:
    ...

Custom directives

@Directive registers a directive definition whose arguments come from the class’s type hints. Apply it with AppliedDirective, validated at build time. See Custom directives & visibility.

from fastql import Directive, Type
from fastql.types import AppliedDirective


@Directive(locations=["FIELD_DEFINITION", "OBJECT"], repeatable=False)
class tag:
    name: str


@Type(directives=[AppliedDirective("tag", {"name": "obj"})])
class Widget: ...

Field visibility

Field(private=True) keeps a Python attribute off the schema (still readable by resolvers); Field(external=True) marks a field as federation-@external.

Enum customization

enum_value(...) overrides a member’s GraphQL name, description, or deprecation_reason.

from fastql import Enum, enum_value


@Enum
class Color:
    RED = "red"
    BLUE = enum_value("blue", name="AZURE", description="cool")

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Decorators and metadata

Class decorators

Field

Arguments

Custom directives

Field visibility

Enum customization

​Class decorators

​Field

​Arguments

​Custom directives

​Field visibility

​Enum customization

Class decorators

Field

Arguments

Custom directives

Field visibility

Enum customization