[keycloak-user] Securing multitenant microservices

Hi, We are currently planning how to implement Keycloak to our solution. Our solution is a multitenant application composed of many microservices with fronting API and React.js clients. Our tenants are all using the same instances of the microservices (those are shared). We will go with implicit token flow, passing the JWT token through all the dependencies to achieve defense-in-depth (aka: the services do the authorization). So as we'll have many tenants we will also have many realms. Because clients are bound to individual realm, we will need to duplicate (re-register through dynamic registration every client) many times. For the worse, we will probably also use UMA, which is bound to the client, hence the privileges will be duplicated as well... Now the questions: 1) Is it somehow possible to inherit or template the definition of the realm, so we would only change the "master realm template" and the changes would propagate to all the individual tenant realms 2) If this is not possible, what is the recommended way to support this scenario with many tenants and many services? Especially when we expect that the clients will evolve, hence updating all the clients+uma in many realms may be very painful... Thanks for your advice! Pavel // PS: if there is any good article or presentation how to achieve this, goal, please send it to me. I will be very grateful.