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

# Add Items to List

> Add property or person IDs to an existing list

Add specific property or person IDs to an existing list. Up to 10,000 IDs per request. Duplicates are ignored. FREE — no credits consumed.

<ParamField path="list_id" type="string" required>
  The list ID to add items to.
</ParamField>

<ParamField body="ids" type="array" required>
  Array of property or person IDs to add (1-10,000 per request).
</ParamField>

<ParamField body="id_type" type="string" default="internal_property_id">
  Type of IDs: `internal_property_id` or `internal_person_id`.
</ParamField>

<ResponseExample>
  ```json 200 Items Added theme={null}
  {
    "data": {
      "added": 42
    }
  }
  ```

  ```json 404 List Not Found theme={null}
  {
    "error": {
      "code": "not_found",
      "message": "No list found with ID abc-123"
    }
  }
  ```
</ResponseExample>