---
title: MetafieldDefinitionIdentifier - GraphQL Admin
description: Identifies a metafield definition by its owner type, namespace, and key.
api_version: 2025-10
api_name: admin
type: object
api_type: graphql
source_url:
  html: https://shopify.dev/docs/api/admin-graphql/latest/objects/metafielddefinitionidentifier
  md: https://shopify.dev/docs/api/admin-graphql/latest/objects/metafielddefinitionidentifier.md
---

# Metafield​Definition​Identifier

object

Identifies a metafield definition by its owner type, namespace, and key.

## Fields

* key

  [String!](https://shopify.dev/docs/api/admin-graphql/latest/scalars/String)

  non-null

  The unique identifier for the metafield definition within its namespace.

* namespace

  [String!](https://shopify.dev/docs/api/admin-graphql/latest/scalars/String)

  non-null

  The container for a group of metafields that the metafield definition is associated with.

* owner​Type

  [Metafield​Owner​Type!](https://shopify.dev/docs/api/admin-graphql/latest/enums/MetafieldOwnerType)

  non-null

  The resource type that the metafield definition is attached to.

***

## Map

No referencing types

***

## Mutations

* [metafield​Definition​Delete](https://shopify.dev/docs/api/admin-graphql/latest/mutations/metafieldDefinitionDelete)

  mutation

  Deletes a [`MetafieldDefinition`](https://shopify.dev/docs/api/admin-graphql/current/objects/MetafieldDefinition). You can identify the definition by providing either its owner type, namespace, and key, or its global ID.

  When you set [`deleteAllAssociatedMetafields`](https://shopify.dev/docs/api/admin-graphql/current/mutations/metafieldDefinitionDelete#arguments-deleteAllAssociatedMetafields) to `true`, the mutation asynchronously deletes all [`Metafield`](https://shopify.dev/docs/api/admin-graphql/current/objects/Metafield) objects that use this definition. This option must be `true` when deleting definitions under the `$app` namespace.

  Learn more about [deleting metafield definitions](https://shopify.dev/docs/apps/build/custom-data/metafields/definitions).

***

## <\~> MetafieldDefinitionIdentifier Mutations

### Mutated by

* <\~>[metafield​Definition​Delete](https://shopify.dev/docs/api/admin-graphql/latest/mutations/metafieldDefinitionDelete)