Function: Field()

function Field(typeFnOrOptions?, fieldOptions?): PropertyDecorator;

Defined in: packages/apollo/src/decorators/type.decorator.ts:131

Decorator for a GraphQL field.

The type is inferred from TypeScript's design:type metadata for primitive types (string → String, number → Number, boolean → Boolean). For all other types — enums, classes, union types — an explicit type factory must be provided; omitting it throws an error at decoration time.

Parameters

Parameter	Type
typeFnOrOptions?	| (() => unknown) | { defaultValue?: unknown; deprecationReason?: string; description?: string; nullable?: boolean; type?: () => unknown; }
fieldOptions?	{ defaultValue?: unknown; deprecationReason?: string; description?: string; nullable?: boolean; }
fieldOptions.defaultValue?	unknown
fieldOptions.deprecationReason?	string
fieldOptions.description?	string
fieldOptions.nullable?	boolean

Returns

PropertyDecorator

Throws

When no explicit type is given and design:type is Object.

Example

@ObjectType()
class User {
  @Field()
  id: string;

  @Field({ nullable: true })
  email?: string;

  @Field(() => [Post])
  posts: Post[];

  // Enum — explicit type factory required
  @Field(() => Role)
  role: Role;
}