<note> <p>This API operation is superseded by <a>AttachTrafficSources</a>, which can attach multiple traffic sources types. We recommend using <code>AttachTrafficSources</code> to simplify how you manage traffic sources. However, we continue to support <code>AttachLoadBalancers</code>. You can use both the original <code>AttachLoadBalancers</code> API operation and <code>AttachTrafficSources</code> on the same Auto Scaling group.</p> </note> <p>Attaches one or more Classic Load Balancers to the specified Auto Scaling group. Amazon EC2 Auto Scaling registers the running instances with these Classic Load Balancers.</p> <p>To describe the load balancers for an Auto Scaling group, call the <a>DescribeLoadBalancers</a> API. To detach a load balancer from the Auto Scaling group, call the <a>DetachLoadBalancers</a> API.</p> <p>This operation is additive and does not detach existing Classic Load Balancers or target groups from the Auto Scaling group.</p> <p>For more information, see <a href="https://docs.aws.amazon.com/autoscaling/ec2/userguide/autoscaling-load-balancer.html">Use Elastic Load Balancing to distribute traffic across the instances in your Auto Scaling group</a> in the <i>Amazon EC2 Auto Scaling User Guide</i>.</p>

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

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