***

title: "TypedCustomSingleFieldConfig"
generated: true
---------------

<GenerationInfo sourceFile="packages/core/src/config/custom-field/custom-field-types.ts" sourceLine="101" packageName="@vendure/core" />

Configures a custom field on an entity in the [CustomFields](/current/core/reference/typescript-api/custom-fields/#customfields) config object.

```ts title="Signature"
type TypedCustomSingleFieldConfig<T extends CustomFieldType, C extends CustomField> = BaseTypedCustomFieldConfig<T, C> & {
    list?: false;
    defaultValue?: DefaultValueType<T>;
    validate?: (
        value: DefaultValueType<T>,
        injector: Injector,
        ctx: RequestContext,
    ) => string | LocalizedString[] | void | Promise<string | LocalizedString[] | void>;
}
```