diff --git a/impl.go b/impl.go
index d8223383..06f4944f 100644
--- a/impl.go
+++ b/impl.go
@@ -99,6 +99,10 @@ func (r *Lark) AppSecret() string {
 	return r.appSecret
 }
 
+func (r *Lark) OpenBaseURL() string {
+	return r.openBaseURL
+}
+
 func (r *Lark) init() {
 	r.wrapDoRequest = chainApiMiddleware(r.apiMiddlewares...)(r.rawRequest)