Using service workers across multiple subdomains

Question

If my web app consists of more than one subdomain, does that mean I have to have multiple service workers, one for each subdomain? Or can I have one service worker that work

Answer 1

Each subdomain is considered a different origin and you must register a service worker for each origin but you can reuse the same source for the service worker by setting the Service-Worker-Allowed response header to the list of scopes the same source can control.