Cursor
auth
OAuth Token Refresh Fails After Cursor AI Refactor
After using Cursor's AI to refactor authentication code, OAuth token refresh requests return 401 Unauthorized errors. The application was previously handling token refresh correctly, but the AI-generated changes broke the flow.
Users are unexpectedly logged out during their sessions, and the app fails to silently refresh expired tokens before making API requests.
Error Messages You Might See
401 Unauthorized
Invalid refresh token
token_expired
refresh_token_revoked
Common Causes
- AI generated incorrect token expiry comparison logic (using < instead of > or vice versa)
- Refresh token endpoint URL was modified incorrectly during refactoring
- Missing token type validation (Bearer token prefix stripped)
- Async/await chain broken, causing refresh to complete after API call
- Removed token storage in localStorage/sessionStorage during cleanup
How to Fix It
Verify the token expiry check uses correct comparison: Date.now() > expiryTime. Check that refresh endpoint matches OAuth provider docs. Ensure Bearer prefix is preserved. Validate token refresh completes before making authenticated requests.
Real developers can help you.
Omar Faruk
As a Product Engineer at Klasio, I contributed to end-to-end product development, focusing on scalability, performance, and user experience.
My work spanned building and refining core features, developing dynamic website templates, integrating secure and reliable payment gateways, and optimizing the overall system architecture.
I played a key role in creating a scalable and maintainable platform to support educators and learners globally.
I'm enthusiastic about embracing new challenges and making meaningful contributions.
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.
Matthew Jordan
I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job.
PawelPloszaj
I'm fronted developer with 10+ years of experience with big projects. I have small backend background too
MFox
Full-stack professional senior engineer (15+years). Extensive experience in software development, qa, and IP networking.
Jen Jacobsen
I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses.
I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain.
Mehdi Ben Haddou
- Founder of Chessigma (1M+ users) & many small projects
- ex Founding Engineer @Uplane (YC F25)
- ex Software Engineer @Amazon and @Booking.com
Vlad Temian
15+ years shipping production infrastructure for startups. Former CTO at qed.builders (acquired by The Sandbox).
Cursor ambassador and agentic tooling builder.
I've scaled systems, automated deployments, and built observability tools for AI coding workflows. I specialize in taking vibe-coded apps from broken prototype to production-ready: fixing Supabase auth/RLS, Stripe integrations, deployment pipelines, and cleaning up AI-generated spaghetti.
I build tools in this space (agentprobe, claudebin, micode) and understand both sides: how AI generates code and why it breaks.
https://blog.vtemian.com/
David Olverson
Solo dev shipping production apps with AI-assisted development. I specialize in rescuing broken Lovable/Bolt/Cursor builds and taking them to production. 10+ apps shipped including SaaS CRMs, gaming platforms, real estate tools, and Discord bots. Stack: Next.js 16, TypeScript, Tailwind CSS, FastAPI, PostgreSQL, Prisma. I use Claude Code with 50+ custom skills for rapid delivery. Average turnaround: 2-4 weeks from broken prototype to production.
Matt Butler
Software Engineer @ AWS
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
Why does my app work in dev but fail in production?
Token expiry times differ between environments. Ensure server time is synced and expiry buffer is adequate (refresh 30s before actual expiry).
How do I debug token refresh?
Add console.log statements before/after refresh call. Check network tab in DevTools for actual refresh request and response.