API Endpoint Type Mismatch After Cursor TypeScript Update
After Cursor refactored your API endpoint code, TypeScript errors report type mismatches between client requests and server responses. The endpoint signatures don't match what the client is sending.
Type definitions or interfaces were likely modified incorrectly during refactoring.
Error Messages You Might See
Common Causes
- Request body interface changed, field names or types modified
- Response type removed optional marker (? or | null)
- Endpoint parameter types changed (string vs number)
- Generic types
used incorrectly after refactoring - Type imports removed or aliased to wrong types
How to Fix It
Compare client request type with server endpoint parameter type. Use TypeScript strict mode to catch issues: strict: true in tsconfig.json. Export types from shared location both use. Run tsc --noEmit to check types. Use VSCode quick fixes (Ctrl+.).
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Get HelpFrequently Asked Questions
How do I share types between client and server?
Create shared types package or folder. Import on both sides. Or generate types from OpenAPI/GraphQL schema.
What's type narrowing?
Checking to determine exact type: typeof x === 'string' ? x.length : x.value. Helps TypeScript understand type at different code paths.