I am an open source developer, who just switched to macOS a few weeks ago. I am basically looking for an alternative to Linux' /etc/nsswitch.conf. Not for custom DNS resolution, that's an easy problem to solve, but for users / groups / hosts resolution via custom network modules. Basically looking for a way how I can hook up into the OS in kind of the same way as an LDAP client would do, and provide my own NSS modules. Just for reference, I am developing rauthy which can do PAM authn / authz in combination with rauthy-pam-nss. It works perfectly fine on Linux systems, and I now want to make it work on macOS as well. I already know that macOS is running its mDNSResponder for DNS instead of having the nsswitch.conf, but I have not found an answer for users, groups and hosts.