# EntityKey

A unique identifier for an entity in the Cloud Identity Groups API.

An entity can represent either a group with an optional `namespace` or a user without a `namespace`. The combination of `id` and `namespace` must be unique; however, the same `id` can be used with different `namespace`s.

| JSON representation |
|---|
| ``` { "id": string, "namespace": string } ``` |

| Fields ||
|---|---|
| `id` | `string` The ID of the entity. For Google-managed entities, the `id` should be the email address of an existing group or user. Email addresses need to adhere to [name guidelines for users and groups](https://support.google.com/a/answer/9193374). For external-identity-mapped entities, the `id` must be a string conforming to the Identity Source's requirements. Must be unique within a `namespace`. |
| `namespace` | `string` The namespace in which the entity exists. If not specified, the `EntityKey` represents a Google-managed entity such as a Google user or a Google Group. If specified, the `EntityKey` represents an external-identity-mapped group. The namespace must correspond to an identity source created in Admin Console and must be in the form of `identitysources/{identity_source}`. |