Auth0 is an option not just for the enterprise. I'm developer advocate there, you get 25,000 users in our free tier with a custom domain, unlimited social conn

Auth0 is an option not just for the enterprise. I'm developer advocate there, you get 25,000 users in our free tier with a custom domain, unlimited social connections, basic attack protection, and more.(https://auth0.com/pricing https://auth0.com/pricing). We also have the Auth0 for Startups program you can apply to and get one year free. (https://auth0.com/startups https://auth0.com/startups) Reach out with any questions. Would love to help you with your project