> Last but not least, cost. I’ll just come out and say it: IMHO, what most vendors charge for being IdP is outrageous. Charging by MAU in an IdP? Really? We all know that the marginal cost for me to have a user in your system is essentially 0. You really gonna charge me 10 cents a month for a row in your database?<p>I've been looking into adding OAuth2/OIDC IdP integrations to an app I'm making. The pricing for most auth-as-a-service is indeed outrageous, and I don't need (or want) JWT. oauth4webapi [1] fits the bill here, is free and certified. Took less than an afternoon to have sign in with Google and another IdP. There's obviously more work to be done, but it's not rocket science.<p>Don't know if there's an equivalent for SAML. But I've certainly considered going into the auth SaaS business a few times. Seems like there's good money to be made.<p>[1] <a href="https://github.com/panva/oauth4webapi">https://github.com/panva/oauth4webapi</a> (TypeScript)