diff --git a/lib/u_async.c b/lib/u_async.c
index 4957f5cf..037a2306 100644
--- a/lib/u_async.c
+++ b/lib/u_async.c
@@ -800,3 +800,13 @@ int uasync_get_wakeup_fd(struct UASYNC* ua) {
     if (!ua || !ua->wakeup_initialized) return -1;
     return ua->wakeup_pipe[1];
 }
+
+/* Lookup socket by file descriptor - returns current pointer even after realloc */
+int uasync_lookup_socket(struct UASYNC* ua, int fd, void** socket_id) {
+    if (!ua || !ua->sockets || !socket_id || fd < 0 || fd >= FD_SETSIZE) {
+        return -1;
+    }
+    
+    *socket_id = socket_array_get(ua->sockets, fd);
+    return (*socket_id != NULL) ? 0 : -1;
+}
diff --git a/lib/u_async.h b/lib/u_async.h
index c0c45dfa..a933eba5 100644
--- a/lib/u_async.h
+++ b/lib/u_async.h
@@ -56,11 +56,14 @@ void uasync_poll(struct UASYNC* ua, int timeout_tb);
 // Mainloop (бесконечный цикл, __noreturn)
 void uasync_mainloop(struct UASYNC* ua);
 
-// Debug statistics
-void uasync_get_stats(struct UASYNC* ua, size_t* timer_alloc, size_t* timer_free, size_t* socket_alloc, size_t* socket_free);
-
-// Print all resources (timers, sockets) for debugging
-void uasync_print_resources(struct UASYNC* ua, const char* prefix);
+// Debug statistics
+void uasync_get_stats(struct UASYNC* ua, size_t* timer_alloc, size_t* timer_free, size_t* socket_alloc, size_t* socket_free);
+
+// Lookup socket by file descriptor - returns current pointer even after realloc
+int uasync_lookup_socket(struct UASYNC* ua, int fd, void** socket_id);
+
+// Print all resources (timers, sockets) for debugging
+void uasync_print_resources(struct UASYNC* ua, const char* prefix);
 
 // Wakeup mechanism for interrupting poll
 int uasync_wakeup(struct UASYNC* ua);