AI app builders
Test the sign-up emails your AI-built app sends.
Claude Code, Codex, Replit, Lovable and Base44 can build sign-up and login in a single prompt. Whether the confirmation email arrives, links to the right place and works exactly once is still on you. Pick your tool for a step-by-step check.
Claude Code
Check the auth emails in apps you build with Anthropic’s coding agent, from localhost to staging.
Read the guide →OpenAI Codex
Run the real email flow once before you merge a Codex change that touches sign-up or login.
Read the guide →Replit
Make sure sign-up and reset emails link to your published Replit app, not the dev URL.
Read the guide →Lovable
Fix the classic Supabase localhost redirect and check every auth email before you launch.
Read the guide →Base44
Test sign-up, invite and login emails, and every user role, with a test account per role.
Read the guide →
Five checks for any AI-built app
- 1The email arrives. Within seconds, from the sender name your users will recognise, and not in a spam folder of a test account nobody reads.
- 2The link goes to the live app. Not localhost:3000 or an old preview URL. This is the single most common bug in AI-built auth flows.
- 3Codes and links work once. A used or expired link should fail with a helpful message, and a new code should replace the old one.
- 4Password reset works end to end. Request, receive, set a new password and sign in with it.
- 5Invites and roles work. Each role gets the right email and lands on the right screens.
Your next sign-up test is one click away.
Free plan, no credit card. Addresses last up to 7 days.
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