---
title: ID - Shop Users API
description: The `ID` scalar type represents a unique identifier, often used to refetch an object or as key for a cache. The ID type appears in a JSON response as a String; however, it is not intended to be human-readable. When expected as an input type, any string (such as `"4"`) or integer (such as `4`) input value will be accepted as an ID.
api_version: unstable latest
source_url:
  html: https://shopify.dev/docs/api/shop-users/latest/scalars/ID
  md: https://shopify.dev/docs/api/shop-users/latest/scalars/ID.md
---

# ID

scalar

The `ID` scalar type represents a unique identifier, often used to refetch an object or as key for a cache. The ID type appears in a JSON response as a String; however, it is not intended to be human-readable. When expected as an input type, any string (such as `"4"`) or integer (such as `4`) input value will be accepted as an ID.

## Map

### Fields with this scalar

* [Metafield​Definition.uuid](https://shopify.dev/docs/api/shop-users/latest/objects/MetafieldDefinition#field-MetafieldDefinition.fields.uuid)