AuthEndpoints compared
AuthEndpoints is a first-party auth API on top of ASP.NET Core Identity. Use it when you own the users. Use something else when you need an OAuth or OpenID Connect server, or when Microsoft's Identity API endpoints already cover the whole job.
vs wiring Identity yourself
You still use Identity, EF Core, and your user type. AuthEndpoints maps the endpoints you would otherwise write: register, login, 2FA, password reset, passkeys. You skip the week of copy-paste and the easy-to-miss hardening.
vs OpenIddict
OpenIddict is an OAuth 2 and OpenID Connect server. Use it when other apps sign in to you as a provider. AuthEndpoints is for your own web and mobile clients talking to your API. First-party cookies or tokens, not a federation server.
vs Identity API endpoints (MapIdentityApi)
Identity API endpoints give you a bearer-token first-party API. AuthEndpoints covers that job and the cookie-app job, plus passkeys, composable modules, and hardening defaults (rate limits, antiforgery, lockout, refresh-token reuse detection). Use MapIdentityApi if the framework sample is enough. Use AuthEndpoints if you need cookies, passkeys, or to compose only the routes you need.