Modify the instance metadata parameters on a running or stopped instance. When you modify the parameters on a stopped instance, they are applied when the instance is started. When you modify the parameters on a running instance, the API responds with a state of “pending”. After the parameter modifications are successfully applied to the instance, the state of the modifications changes from “pending” to “applied” in subsequent describe-instances API calls. For more information, see <a href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html">Instance metadata and user data</a> in the <i>Amazon EC2 User Guide</i>.

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

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