Handling CORS for Express Deployed on Vercel Using vercel.json
Overview This is a memo on how to handle CORS for Express deployed on Vercel using vercel.json. Background I implemented CORS handling for the program introduced in the following article. The following was used as a reference. https://vercel.com/guides/how-to-enable-cors Method The solution is as follows. While there may be other approaches, adding headers resolved the issue. https://github.com/nakamura196/dts-typescript/commit/4c28f66b2af68950656dcb812f3e941d1b9b5feb { } " " ] " ] " ] " ] v b , r , r , h e u { } e { } e { } e { } r i w d a s l " " r " " i " " " d " " ] i d s u i s d r s d p e s h o s r s t o e e o e e r o e { { { } { } n " c e e u s c u s r s u a , " : " " s r t t r t m " r d " " " " " " : : : " c i s c i a : c e k k k v k v [ : e n " e n n e r e e e a e a 2 " " " a : " a e [ " s y y y l y l , s @ [ : t : t n : " " " " u " u r v i [ i t : : : : e : e c e " " " " " " / r n n : / [ " " " : " : i c a " " " a A A A A n e p : , : t p c c c " c " d l i r i c c c G c X e / / " " u / e e e E e - x n d / / e ( s s s T s C . o t s a . s s s , s S t d s r p * - - - O - R s e ( c i ) C C C P C F " " . / " o o o T o - , i d , n n n I n T ) n t t t t O t o " d s r r r N r k , e " o o o S o e x , l l l , l n . - - - P - , t A A A A A s l l l T l X " l l l C l - o o o H o R w w w , w e - - - D - q C O M E H u r r e L e e e i t E a s d g h T d t e i o E e e n n d , r d t " s P s - i , " O " W a , S , i l " T t s v , h " a P , , l U u T A " e " c v " c a : e l p u " t e * , " " : A } c " , c t e r p u t e - " V e } r , s i o n , C o n t e n t - L e n g t h , C o n t e n t - M D 5 , C o n t e n t - T y p e , D a t e , X - A p i - V e r s i o n " Summary I hope this serves as a helpful reference. ...