.

packages/taiko-client/preconfapi.sh

@@ -1,3 +1,4 @@
 L2_HTTP=https://rpc.helder.taiko.xyz \
 TAIKO_L1=0xf92d16327ADB54e13D13A90e7Cd092962c9e7a8f \
+CORS_ORIGINS="*" \
 go run cmd/main.go preconfapi

packages/taiko-client/preconfapi/server/api.go

@@ -157,11 +157,11 @@ func (s *PreconfAPIServer) GetTransactionByHash(c echo.Context) error {
 
 		return nil
 	}); err != nil {
-		return c.JSON(http.StatusNotFound, tx)
+		return c.JSON(http.StatusNotFound, nil)
 	}
 
 	if tx == nil {
-		return c.JSON(http.StatusNotFound, tx)
+		return c.JSON(http.StatusNotFound, nil)
 	}
 
 	return c.JSON(http.StatusOK, tx)

packages/taiko-client/preconfapi/server/server.go

@@ -93,6 +93,8 @@ func (s *PreconfAPIServer) configureMiddleware(corsOrigins []string) {
 	s.echo.Use(middleware.CORSWithConfig(middleware.CORSConfig{
 		AllowOrigins:     corsOrigins,
 		AllowCredentials: true,
+		AllowMethods:     []string{echo.GET, echo.HEAD, echo.PUT, echo.PATCH, echo.POST, echo.DELETE},
+		AllowHeaders:     []string{echo.HeaderOrigin, echo.HeaderContentType, echo.HeaderAccept},
 	}))
 }