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
401 UnauthorizedInvalid refresh tokentoken_expiredrefresh_token_revoked

Common Causes

  1. AI generated incorrect token expiry comparison logic (using < instead of > or vice versa)
  2. Refresh token endpoint URL was modified incorrectly during refactoring
  3. Missing token type validation (Bearer token prefix stripped)
  4. Async/await chain broken, causing refresh to complete after API call
  5. 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.

Rudra Bhikadiya Rudra Bhikadiya I build and fix web apps across Next.js, Node.js, and DBs. Comfortable jumping into messy code, broken APIs, and mysterious bugs. If your project works in theory but not in reality, I help close that gap. Stanislav Prigodich Stanislav Prigodich 15+ years building iOS and web apps at startups and enterprise companies. I want to use that experience to help builders ship real products - when something breaks, I'm here to fix it. Matthew Jordan 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. 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. 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. BurnHavoc BurnHavoc Been around fixing other peoples code for 20 years. Tejas Chokhawala Tejas Chokhawala Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript. Focused on performance, clean architecture and shipping fast. Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools. Jen Jacobsen 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. rayush33 rayush33 JavaScript (React.js, React Native, Node.js) Developer with demonstrated industry experience of 4+ years, actively looking for opportunities to hone my skills as well as help small-scale business owners with solutions to technical problems 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.

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Frequently 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.

Related Cursor Issues

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