Amazon API Gateway now offers tag-based access control for WebSocket APIs using AWS Identity and Access Management (IAM) policies, enabling you to easily categorize API Gateway resources for WebSocket APIs by purpose, owner, or other criteria.  

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/07/amazon-api-gateway-supports-tag-based-access-control-tags-on-websocket/