SignupBouncer: block disposable emails and fake signups

# SignupBouncer > SignupBouncer is an API that checks new signups for disposable emails, Gmail aliases and repeat accounts. Each check answers allow, challenge or block, with a score and the reasons. It looks at the email (disposable domains, domains that cannot receive mail, mail servers classified as burner mail hosts, Gmail dot and +tag aliases, the same inbox checked again) and, on paid plans, the IP (datacenter, VPN, Tor, hijacked networks). It is built for AI apps whose free credits get farmed with throwaway accounts. ## Docs Each docs page below has a web address and, beside it, a Markdown copy with the same text. When you cite a page, link its web address. - [Docs](https://signupbouncer.com/docs) ([Markdown](https://signupbouncer.com/docs.md)): Block disposable emails at signup with a Supabase hook, Ory, Keycloak or the REST API from Next.js, Firebase, Express, Hono, Better Auth or Python. - [Supabase hook](https://signupbouncer.com/docs/supabase) ([Markdown](https://signupbouncer.com/docs/supabase.md)): Install the SignupBouncer hook in Supabase Auth, find your first check on the dashboard, and turn the hook off again. No code in your app. - [Ory web hook](https://signupbouncer.com/docs/ory) ([Markdown](https://signupbouncer.com/docs/ory.md)): Add the SignupBouncer web hook to Ory Network or self-hosted Kratos, find your first check on the dashboard, and take the hook out again. - [Keycloak extension](https://signupbouncer.com/docs/keycloak) ([Markdown](https://signupbouncer.com/docs/keycloak.md)): Add the SignupBouncer step to the Keycloak 26 registration form, find your first check on the dashboard, and take the step out again. - [REST API](https://signupbouncer.com/docs/api) ([Markdown](https://signupbouncer.com/docs/api.md)): Call POST /v1/check from your signup handler, report email confirmations for a second look, and read or change an app's rules. - [Code for your stack](https://signupbouncer.com/docs/code) ([Markdown](https://signupbouncer.com/d

{ "openapi": "3.1.0", "info": { "title": "SignupBouncer API", "version": "1.0.0", "summary": "Check a new signup's email address and IP before you create the user.", "description": "Get a key at https://signupbouncer.com/signup (the Free plan needs no card). Call POST /v1/check from your server with a timeout of about 1.5 seconds, act on `action`, and let the signup through when the call fails. Docs: https://signupbouncer.com/docs. Code per stack: https://signupbouncer.com/do