package main import ( "github.com/gin-gonic/gin" ) func CORSMiddleware() gin.HandlerFunc { return func(c *gin.Context) { c.Writer.Header().Set("Access-Control-Allow-Origin", "*") c.Writer.Header().Set("Access-Control-Allow-Credentials", "true") c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization") c.Writer.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE") if c.Request.Method == "OPTIONS" { c.AbortWithStatus(204) return } c.Next() } } func main() { r := gin.Default() r.Use(CORSMiddleware()) r.GET("/api/data", func(c *gin.Context) { c.JSON(200, gin.H{"message": "Custom CORS enabled"}) }) r.Run(":9999") }