--- title: MetafieldDefinitionCreatePayload - GraphQL Admin description: Return type for `metafieldDefinitionCreate` mutation. api_version: 2025-10 api_name: admin type: payload api_type: graphql source_url: html: https://shopify.dev/docs/api/admin-graphql/latest/payloads/metafielddefinitioncreatepayload md: https://shopify.dev/docs/api/admin-graphql/latest/payloads/metafielddefinitioncreatepayload.md --- # Metafield​Definition​Create​Payload payload Return type for `metafieldDefinitionCreate` mutation. ## Fields * created​Definition [Metafield​Definition](https://shopify.dev/docs/api/admin-graphql/latest/objects/MetafieldDefinition) The metafield definition that was created. * user​Errors [\[Metafield​Definition​Create​User​Error!\]!](https://shopify.dev/docs/api/admin-graphql/latest/objects/MetafieldDefinitionCreateUserError) non-null The list of errors that occurred from executing the mutation. *** ## Mutations with this payload * [metafield​Definition​Create](https://shopify.dev/docs/api/admin-graphql/latest/mutations/metafieldDefinitionCreate) mutation Creates a [`MetafieldDefinition`](https://shopify.dev/docs/api/admin-graphql/current/objects/MetafieldDefinition) that establishes structure and validation rules for metafields. The definition specifies the data type, validation constraints, and access permissions for metafields with a given namespace and key combination. When you create a new definition, the system validates any existing unstructured metafields matching the same owner type, namespace, and key against it. The system updates each valid metafield's type to match the definition. Invalid metafields remain unchanged but must conform to the definition when updated. Learn more about [creating metafield definitions](https://shopify.dev/docs/apps/build/custom-data/metafields/definitions). *** ## Map ### Mutations with this payload * [metafield​Definition​Create](https://shopify.dev/docs/api/admin-graphql/latest/types/metafieldDefinitionCreate)