Common Issues auth

Login or Signup Not Working in My AI App

Users try to log in or create an account but nothing happens, they get an error, or they're stuck in a loop. This is one of the most common issues with AI-generated apps because auth involves multiple moving parts.

Error Messages You Might See

Invalid login credentials Email not confirmed User already registered Failed to fetch 401 Unauthorized Redirect URI mismatch
Invalid login credentialsEmail not confirmedUser already registeredFailed to fetch401 UnauthorizedRedirect URI mismatch

Common Causes

  • Auth provider (Supabase, Firebase, Auth0) is not properly configured
  • Redirect URLs are wrong — the app sends users to the wrong page after login
  • Session or token management is broken — users appear logged in but the app doesn't recognize them
  • Email confirmation is required but the emails aren't being sent
  • Row Level Security (RLS) policies are blocking access to user data

How to Fix It

  1. Open browser dev tools (F12) and check the Network tab during login — look for failed API calls
  2. Verify your auth provider's redirect URL matches your actual app URL
  3. Check if email confirmation is enabled and whether emails are being sent (check spam folder)
  4. If using Supabase, check RLS policies — they often block legitimate queries
  5. Make sure your auth provider's API keys are correct in your environment variables

Real developers can help you.

hanson1014 hanson1014 Full-stack developer experienced in fixing and deploying AI-generated apps from Lovable, Bolt.new, Cursor, and Replit. I specialize in debugging Supabase integration issues (auth flows, RLS policies, database connections), fixing broken deployments, resolving routing/blank screen problems, and cleaning up messy React/Vite codebases. I also build production apps with the Claude API and have shipped a Mac desktop dev tool (Nexterm from scratch. Based in Hong Kong, fast turnaround. Taufan Taufan I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms. Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact. Sage Fulcher Sage Fulcher Hey I'm Sage! Im a Boston area software engineer who grew up in South Florida. Ive worked at a ton of cool places like a telehealth kidney care startup that took part in a billion dollar merger (Cricket health/Interwell health), a boutique design agency where I got to work on a ton of exciting startups including a photography education app, a collegiate Esports league and more (Philosophie), a data analytics as a service startup in Cambridge (MA) as well as at Phillips and MIT Lincoln Lab where I designed and developed novel network security visualizations and analytics. I've been writing code and furiously devoted to using computers to make people’s lives easier for about 17 years. My degree is in making computers make pretty lights and sounds. Outside of work I love hip hop, the Celtics, professional wrestling, magic the gathering, photography, drumming, and guitars (both making and playing them) BurnHavoc BurnHavoc Been around fixing other peoples code for 20 years. MFox MFox Full-stack professional senior engineer (15+years). Extensive experience in software development, qa, and IP networking. Costea Adrian Costea Adrian Embedded Engineer specilizing in perception systems. Latest project was a adas camera calibration system. Antriksh Narang Antriksh Narang 5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies. Nam Tran Nam Tran 10 years as fullstack developer Meïr Ankri Meïr Ankri Full-stack developer specializing in React / Next.js / Node.js with 6+ years of experience. I've worked across various sectors including automotive (Reezocar/Société Générale), healthcare (Medical Link SaaS), and e-commerce (Glasman). I build web apps end-to-end, from architecture to production, with a focus on scalability, performance, and code quality. I also mentor junior developers and contribute to technical decisions and code reviews. Jacek Rozanski Jacek Rozanski Senior PHP/Symfony developer and DevOps engineer with 20+ years of professional experience, running opcode.pl (web development agency, est. 2004). Day job: I'm the sole backend developer at merketing company where I own and maintain 11 PHP/Symfony microservices on AWS (ECS Fargate, RDS, S3, CloudFront), handle the full CI/CD pipeline (Bitbucket Pipelines, Docker), and manage monitoring with Sentry and CloudWatch. These services handle high request volumes in production every month. What I bring to AI-built apps: - I audit and fix security issues (OWASP methodology), performance bottlenecks, and architectural problems in codebases generated by Cursor, Claude Code, Lovable, Bolt, and v0 - I refactor AI-generated prototypes into production-grade applications with proper error handling, testing, and clean architecture (SOLID, DDD, hexagonal architecture) - I set up the infrastructure AI tools don't touch: AWS hosting, CI/CD pipelines, automated deployments, database optimization, monitoring, and alerting - I integrate external services: payment providers, email systems, partner APIs, SSO/auth Tech stack: PHP 8.x, Symfony, React, Next.js, PostgreSQL, MySQL, Docker, AWS (ECS, RDS, S3, SQS/SNS, CloudFront), Terraform, Supabase. I also use AI tools daily (Claude Code, Cursor) in my own workflow, so I understand both the strengths and the gaps in AI-generated code. Based in Poland (CET timezone). Available for async work and calls during EU/US business hours.

Describe what's wrong in plain English. No technical knowledge needed.

Get Help

Frequently Asked Questions

Users can sign up but can't log in. What's wrong?

Usually an email confirmation issue — check if your auth provider requires email verification. Also verify that the login redirect URL is correct.

Login works on localhost but not in production. Why?

Your auth provider's redirect URLs probably still point to localhost. Update them to your production domain in the auth provider's dashboard.

Related Common Issues Issues

Can't fix it yourself?
Real developers can help.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help