Not an app developer, so genuinely curious: would offering only Google and Apple SSO (alongside email and password) be enough coverage for most users to reduce signup friction? Apps are rolling Apple auth out now as the deadline for implementation has passed.

My understanding is that to use Facebook as an auth mechanism, you must use their SDK (and personal data vacuuming along with it), so dropping Facebook auth would allow apps to drop the SDK, which would be a win for both privacy advocates and users who enjoy their apps working even when Facebook breaks something.

> My understanding is that to use Facebook as an auth mechanism, you must use their SDK

Does anyone know more about this?

As far as I remember Facebook does support being and openid connect authentication provider so it should be theoretically possible without their SDK. But it might be that they put some practical restrictions in place to force usage of their API??

I believe the T's & C's of the FB developer platform specifies that you can only use the Android/iOS SDKs for auth. You can probably get around it using openid, but you risk your developer keys being revoked.

Lots of login providers are out now. Okta, Auth0.