---
title: Changes to metafield definition error codes - Shopify developer changelog
description: >-
  Shopify’s developer changelog documents all changes to Shopify’s platform.
  Find the latest news and learn about new platform opportunities.
source_url:
  html: 'https://shopify.dev/changelog/changes-to-metafield-definition-error-codes'
  md: 'https://shopify.dev/changelog/changes-to-metafield-definition-error-codes.md'
metadata:
  effectiveApiVersion: 2022-04
  affectedApi: []
  primaryTag:
    displayName: API
    handle: api
  secondaryTag:
    displayName: Update
    handle: update
  indicatesActionRequired: false
  createdAt: '2022-03-18T12:28:49-04:00'
  postedAt: '2022-03-21T00:00:00-04:00'
  updatedAt: '2024-12-13T17:24:33-05:00'
  effectiveAt: '2022-03-21T00:00:00-04:00'
---

March 21, 2022

Tags:

* API
* 2022-04

# Changes to metafield definition error codes

As of GraphQL Admin API version 2022-04, an error returns when a metafield definition is created with invalid characters in either the `key` or the `namespace` fields. The `key` and `namespace` fields can contain only alphanumeric characters, hyphens, and underscores.

[Learn more about the `MetafieldDefinition` object](https://shopify.dev/api/admin-graphql/current/objects/MetafieldDefinition).