diff --git a/tools/chatgui/transport/gui_bridge.h b/tools/chatgui/transport/gui_bridge.h
index a68047f5..08b9f79f 100644
--- a/tools/chatgui/transport/gui_bridge.h
+++ b/tools/chatgui/transport/gui_bridge.h
@@ -226,6 +226,8 @@ void gui_bridge_set_dm_conv_updated_cb(gui_dm_conv_updated_fn cb);
  * data: [conv_id_len:1][conv_id:var][count:2]([dir:1][seq:8][ts:8][author:8][ct_len:1][ct:var][data_len:2][data:var])* */
 typedef void (*gui_dm_messages_fn)(const uint8_t* data, int len);
 void gui_bridge_set_dm_messages_cb(gui_dm_messages_fn cb);
+/* CHAT_EVT_ATTACHMENT_PREPARATION: target + job UUID + state. */
+void gui_bridge_set_attachment_preparation_cb(gui_dm_messages_fn cb);
 
 /* uTun nodeinfo callback — registered via utun_add_nodeinfo_cbk, called from uasync thread */
 void gui_nodeinfo_cb_impl(struct TOPO_GROUP* group, struct TOPO_GROUP_NODE* nq, void* arg);
diff --git a/tools/chatgui/transport/gui_bridge_impl.cpp b/tools/chatgui/transport/gui_bridge_impl.cpp
index 678de4e5..b3a7bc6c 100644
--- a/tools/chatgui/transport/gui_bridge_impl.cpp
+++ b/tools/chatgui/transport/gui_bridge_impl.cpp
@@ -61,6 +61,7 @@ static gui_radio_talk_fn             g_radio_talk_cb           = nullptr;
 static gui_dm_msg_received_fn        g_dm_msg_received_cb      = nullptr;
 static gui_dm_conv_updated_fn        g_dm_conv_updated_cb      = nullptr;
 static gui_dm_messages_fn            g_dm_messages_cb          = nullptr;
+static gui_dm_messages_fn            g_attachment_preparation_cb = nullptr;
 static struct UASYNC*        g_ua                 = nullptr;
 static struct UTUN_INSTANCE* g_inst               = nullptr;
 
@@ -270,6 +271,9 @@ void GuiBridgeReceiver::processPost(int eventType, QByteArray data) {
     case GUI_EVT_DM_MESSAGES:
         if (g_dm_messages_cb) g_dm_messages_cb(d, dlen);
         break;
+    case CHAT_EVT_ATTACHMENT_PREPARATION:
+        if (g_attachment_preparation_cb) g_attachment_preparation_cb(d, dlen);
+        break;
     case GUI_EVT_CALL_INCOMING:
         if (dlen >= 1 + 8 + 8) {
             uint8_t chLen = d[0];
@@ -542,6 +546,10 @@ void gui_bridge_set_dm_messages_cb(gui_dm_messages_fn cb) {
     g_dm_messages_cb = cb;
 }
 
+void gui_bridge_set_attachment_preparation_cb(gui_dm_messages_fn cb) {
+    g_attachment_preparation_cb = cb;
+}
+
 } /* extern "C" */
 
 /* ── uTun nodeinfo callback (called from uasync thread) ── */