Last time I checked we had TLS Client Certificates and TLS Certificate Pinning. So yes, we do have mutual auth. Additionally, OAuth2 is not an authentication flow.

> Additionally, OAuth2 is not an authentication flow.

I've heard this before, but tbh I'm not familiar enough with auth systems to see why it's true. I've certainly used "login with Facebook", etc. as an alternative to email/password login for sites I've created in the past, and I've seen others do so.

Do you mind elaborating?

I tried out various image labeling APIs, including Google Vision (Safe Search) for exactly this use case (moderation). I was honestly astonished at the pricing of these APIs. Google is somewhere at 1.50€ for 1000 images which is - imo - very expensive. I tried out the default models that come with Tensorflow but well, they are trained on scientific datasets which typically involve species and flowers - no luck there either. Any good tips for pre-trained models that solve this (for tensorflow)?

You can use nudebox from https://machinebox.io, is an API in a docker container (disclaimer: I built it)

I've found promising results trying this one out:

https://github.com/yahoo/open_nsfw

Download 1000 NSFW images, 1000 racy images and 100 completely SFW images. Train a model and publish it on GitHub?

Would be really interested to see the results of this.

Also, consider using Dataturks to create and host the dataset.