<p>Deregisters the specified task definition by family and revision. Upon deregistration, the task definition is marked as <code>INACTIVE</code>. Existing tasks and services that reference an <code>INACTIVE</code> task definition continue to run without disruption. Existing services that reference an <code>INACTIVE</code> task definition can still scale up or down by modifying the service's desired count. If you want to delete a task definition revision, you must first deregister the task definition revision.</p> <p>You can't use an <code>INACTIVE</code> task definition to run new tasks or create new services, and you can't update an existing service to reference an <code>INACTIVE</code> task definition. However, there may be up to a 10-minute window following deregistration where these restrictions have not yet taken effect.</p> <note> <p>At this time, <code>INACTIVE</code> task definitions remain discoverable in your account indefinitely. However, this behavior is subject to change in the future. We don't recommend that you rely on <code>INACTIVE</code> task definitions persisting beyond the lifecycle of any associated tasks and services.</p> </note> <p>You must deregister a task definition revision before you delete it. For more information, see <a href="https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_DeleteTaskDefinitions.html">DeleteTaskDefinitions</a>.</p>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}