Add exchange api endpoint, fix jwt authtoken var type error

Signed-off-by: Asai Neko <sugar@sne.moe>

pkgs/authtoken/authtoken.go

@@ -288,6 +288,7 @@ func (self *Token) HeaderVerify(header string) (string, error) {
 	)
 
 	if err != nil || !token.Valid {
+		fmt.Println(err)
 		return "", errors.New("invalid or expired token")
 	}