[manigandham]

It's a C#/.NET app but it's not tied to it. OAuth/OIDC is all HTTP endpoints and redirects.

IdentityServer does have more of a framework/library approach so you can integrate it into your own code and apps but there's a turnkey UI project available that just needs some settings in a JSON config file to get running.

https://github.com/IdentityServer/IdentityServer4.Quickstart...

They also have the only good OIDC javascript client that implements the new PKCE flow for client-side apps: https://github.com/IdentityModel/oidc-client-js