> ## Documentation Index
> Fetch the complete documentation index at: https://docs.attio.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Actor reference

> References to workspace members and others

Actor references are used to link to [actors](/docs/actors) in Attio. You're most likely to encounter this attribute via the `created_by` attribute which is available on every object, the `owner` attribute on a deal object, or the `strongest_connection_user` on a company or person.

Actor reference attributes can be single-select or multi-select.

Please note, in the mobile and web clients, attributes of this type are marked as "User" attributes.

### Reading values

Actor reference values have two properties, `referenced_actor_type` and `referenced_actor_id`. The `referenced_actor_type` can be one of `"api-token"`, `"workspace-member"` or `"system"`. The `referenced_actor_id` is a UUID, or the value `null`, that uniquely identifies the actor.

<CodeGroup>
  ```jsonc Example: workspace member theme={"system"}
  {
    "active_from": "2023-04-03T15:21:06.447000000Z",
    "active_until": null,
    "created_by_actor": {
      /*...*/
    },
    "attribute_type": "actor-reference",
    "referenced_actor_type": "workspace-member",
    "referenced_actor_id": "fbe75eb0-d704-4d12-9e41-aa187e60ed73"
  }
  ```
</CodeGroup>

### Writing values

Currently, the only type of [actor](/docs/actors) that can be explicitly set in our API is `"workspace-member"`. We may expand this list in future.

When writing references to workspace members, we allow you to identify actors by email addresses. You may do this either by passing an email address string directly, or by using an object with the key `workspace_member_email_address`.

Actor reference attributes may be multi-select or single-select. When writing to multi-select attributes, you must always wrap values in an array. Single-select attributes accept unwrapped data.

<CodeGroup>
  ```json Using email string theme={"system"}
  {
    "owner": ["[email protected]"]
  }
  ```

  ```json Single-select string theme={"system"}
  {
    "owner": "[email protected]"
  }
  ```

  ```json Using workspace_member_email_address theme={"system"}
  {
    "owner": [
      {
        "workspace_member_email_address": "[email protected]"
      }
    ]
  }
  ```
</CodeGroup>

You may also specify the actor type and ID explicitly using an object with the keys `referenced_actor_type` and `referenced_actor_id`.

<CodeGroup>
  ```json Using workspace member ID theme={"system"}
  {
    "owner": [
      {
        "referenced_actor_type": "workspace-member",
        "referenced_actor_id": "50cf242c-7fa3-4cad-87d0-75b1af71c57b"
      }
    ]
  }
  ```
</CodeGroup>

### Filtering

Actor reference values can only be filtered using both the `referenced_actor_type` and `referenced_actor_id` properties. If using explicit operators, only the `$eq` operator is supported. For example:

<CodeGroup>
  ```json Value written by workspace member theme={"system"}
  {
    "filter": {
      "created_by": {
        "referenced_actor_type": "workspace-member",
        "referenced_actor_id": "ec44a06c-b690-4e4f-95b6-757fb4e2f55f"
      }
    }
  }
  ```

  ```json Value written by API token theme={"system"}
  {
    "filter": {
      "created_by": {
        "referenced_actor_type": "api-token"
      }
    }
  }
  ```

  ```json Expanded format theme={"system"}
  {
    "filter": {
      "created_by": {
        "referenced_actor_type": {
          "$eq": "api-token"
        }
      }
    }
  }
  ```
</CodeGroup>