Add an /api/authcheck and use it to toggle logout/login link on top header.

api/auth.go

@@ -15,6 +15,12 @@ import (
   . "MY/webapp/common"
 )
 
+func GetApiAuthCheck(c *fiber.Ctx) error {
+  _, err := CheckAuthed(c, false)
+  // auth failure or not authed is determined by err, with nil meaning YES AUTHED
+  return c.JSON(fiber.Map{"is_authed": err == nil})
+}
+
 func GetApiLogout(c *fiber.Ctx) error {
   err := LogoutUser(c)
   if err != nil { return IfErrNil(err, c) }

api/handlers.go

@@ -97,6 +97,7 @@ func Setup(app *fiber.App) {
   app.Post("/api/link", PostApiLink)
 
   // api/auth.go
+  app.Get("/api/authcheck", GetApiAuthCheck)
   app.Get("/api/logout", GetApiLogout)
   app.Post("/api/register", PostApiRegister)
   app.Post("/api/login", PostApiLogin)