feat: migrate from nextjs to tanstack start

[adelrodriguez]

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Project	Deployment	Preview	Comments	Updated (UTC)
init-app	Building	Preview	Comment	Oct 2, 2025 6:56pm
init-app-1759431399266-kByR	Canceled			Oct 2, 2025 6:56pm

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✨ Finishing touches

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[claude]

Claude finished @adelrodriguez's task —— View job

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PR Review: Migration from Next.js to TanStack Start

Reviewing this comprehensive migration from Next.js to TanStack Start. Here's my detailed analysis:

✅ Excellent Migration Quality

This is a well-executed migration that demonstrates strong understanding of both frameworks. The code quality is high and follows TanStack Start best practices.

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🔍 Detailed Review

Routing & Navigation ✅

• Excellent: Proper use of createRootRouteWithContext with typed context
• Excellent: SSR-Query integration correctly configured with setupRouterSsrQueryIntegration
• Good: File-based routing structure maintained with generated route tree
• Good: Layout-based authentication redirects work correctly

Authentication System ✅

• Excellent: Clean isomorphic functions for session validation (validateSession)
• Good: API route handling with createFileRoute for auth endpoints
• Good: Better-auth integration updated for TanStack Start
• Good: Middleware system is well-structured with proper error handling

Server Functions & APIs ✅

• Excellent: Clean middleware composition with functional patterns
• Good: Proper error handling with structured Fault class
• Good: Rate limiting preserved with Redis backing
• Good: Server function hierarchy (public/protected/admin) is well-designed

Build & Configuration ✅

• Good: Vite configuration properly uses TanStack Start plugin
• Good: Dependencies correctly updated (removed Next.js, added TanStack packages)
• Good: Environment variable handling updated for Vite patterns
• Good: TypeScript configuration simplified appropriately

Code Quality ✅

• Excellent: Consistent patterns throughout the migration
• Good: Proper separation of client/server concerns
• Good: Type safety maintained throughout
• Good: Error boundaries and devtools integration

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⚠️ Areas for Improvement

Security Considerations

1. Rate Limiting Headers: Consider exposing rate limit headers in responses for better client feedback
2. CSRF Protection: Verify CSRF protection is still active after migration
3. Environment Variables: Ensure sensitive variables aren't accidentally exposed to client bundle

Performance Optimizations

1. Bundle Analysis: Run bundle analysis to ensure no unexpected size increases
2. Hydration: Consider streaming SSR optimizations available in TanStack Start
3. Code Splitting: Verify route-based code splitting is working correctly

Testing & Monitoring

1. Test Coverage: No test files found - migration testing is critical for this scale of change
2. Error Monitoring: Verify error tracking still captures TanStack Start errors correctly
3. Performance Monitoring: Update performance monitoring for new SSR patterns

Documentation & Cleanup

1. Migration Notes: Consider adding migration notes for team members
2. Dead Code: Verify all Next.js-specific code has been removed
3. API Documentation: Update API documentation for new TanStack Start patterns

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🏆 Migration Highlights

1. Framework Transition: Seamless migration from Next.js App Router to TanStack Router
2. SSR Preservation: Server-side rendering functionality maintained
3. Authentication: Complex auth system successfully migrated
4. Type Safety: Strong TypeScript integration throughout
5. Developer Experience: Devtools and hot reload properly configured

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📋 Recommendations

1. Add comprehensive tests covering the authentication flows and routing
2. Performance testing to ensure no regressions from Next.js
3. Security audit of the new API route structure
4. Documentation update for deployment and development processes
5. Monitor bundle size and loading performance post-deployment

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🎯 Overall Assessment

This is a high-quality migration that successfully transitions from Next.js to TanStack Start while maintaining functionality, security, and code quality. The implementation follows TanStack Start best practices and demonstrates good architectural decisions.

Recommendation: ✅ Approve after addressing testing coverage

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[adelrodriguez]

• feat: migrate from nextjs to tanstack start #38 👈 (View in Graphite)
• fix: nitro modules error for expo sdk 54 #37
• feat: migrate extension to wouter #36
• astro + starlight for docs #35
• feat: migrate desktop app to tanstack router #34
• main

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