diff --git a/src/chat/chat_sync.c b/src/chat/chat_sync.c
index a8985c74..31957657 100644
--- a/src/chat/chat_sync.c
+++ b/src/chat/chat_sync.c
@@ -394,6 +394,20 @@ static void cs_schedule_sync(struct chat_sync* cs) {
     DEBUG_DEBUG(DEBUG_CATEGORY_MEMBER_SYNC, "%s: sync scheduled in %ums", CS_ID, CS_SYNC_INTERVAL_MS);
 }
 
+/* ── Peer sleep (keepalive-протокол): спячка → отменить сессии; пробуждение → пересинхронизация ── */
+
+static void cs_on_peer_sleep(struct UTUN_INSTANCE* inst, uint64_t peer_node_id, int sleeping, void* arg) {
+    struct chat_sync* cs = (struct chat_sync*)arg;
+    if (!cs || !cs->initialized) return;
+    if (sleeping) {
+        DEBUG_INFO(DEBUG_CATEGORY_MEMBER_SYNC, "%s: peer sleep peer=0x%016llx — cancel member_sync sessions", CS_ID, (unsigned long long)peer_node_id);
+        merkle_sync_cancel_peer(inst, peer_node_id);
+    } else {
+        DEBUG_INFO(DEBUG_CATEGORY_MEMBER_SYNC, "%s: peer awake peer=0x%016llx — schedule sync", CS_ID, (unsigned long long)peer_node_id);
+        cs_schedule_sync(cs);
+    }
+}
+
 /* ── Peer status change (GUI + online-бар + schedule_sync; онлайн в БД не хранится) ── */
 
 static void cs_on_peer_status_changed(struct chat_sync* cs, uint64_t peer, int online) {
@@ -643,6 +657,7 @@ int chat_sync_init(struct UTUN_INSTANCE* inst) {
 
     member_sync_init(inst);
     member_sync_add_apply_cbk(inst, cs_on_member_applied, cs);
+    utun_add_peer_sleep_cbk(inst, cs_on_peer_sleep, cs);
     chat_admin_init(inst);
     chat_join_init(inst);
 
@@ -658,6 +673,7 @@ void chat_sync_destroy(struct UTUN_INSTANCE* inst) {
     if (cs->invite_send_timer) { uasync_cancel_timeout(inst->ua, cs->invite_send_timer); cs->invite_send_timer = NULL; }
     if (cs->sync_scheduled) { cs->sync_scheduled = 0; cs_flush_sync(cs); }
     member_sync_remove_apply_cbk(inst, cs_on_member_applied, cs);
+    utun_remove_peer_sleep_cbk(inst, cs_on_peer_sleep, cs);
     cs_pending_free_all(cs);
     member_sync_destroy(inst);
     chat_admin_destroy(inst);
diff --git a/src/chat/merkle_sync.c b/src/chat/merkle_sync.c
index f4f1105f..9805a038 100644
--- a/src/chat/merkle_sync.c
+++ b/src/chat/merkle_sync.c
@@ -692,6 +692,12 @@ static void _recv_cb(struct ETCP_CONN* conn, struct ll_entry* entry) {
     struct merkle_sync* ms = inst ? inst->msync : NULL;
     if (!ms || !ms->initialized) { u_free(entry->dgram); queue_entry_free(entry); return; }
     uint64_t peer = conn ? conn->peer_node_id : 0;
+
+    /* пир в спячке — не обрабатываем его синхронизацию (server-side throttling) */
+    if (conn && conn->peer_sleeping) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_MEMBER_SYNC, "%s: recv DROP — peer=0x%016llx sleeping", MS_ID, (unsigned long long)peer);
+        u_free(entry->dgram); queue_entry_free(entry); return;
+    }
     const uint8_t* d = entry->dgram;
     size_t dlen = entry->len;
 
@@ -882,6 +888,15 @@ int merkle_sync_start(struct UTUN_INSTANCE* inst, uint64_t peer,
     if (!inst || !ns || !ms || !ms->initialized) return -1;
     _ensure_table(ms);
 
+    /* пир в спячке — не инициируем синхронизацию (server-side throttling) */
+    {
+        struct ETCP_CONN* pc = ms_find_conn_for_node(inst, peer);
+        if (pc && pc->peer_sleeping) {
+            DEBUG_DEBUG(DEBUG_CATEGORY_MEMBER_SYNC, "%s: start SKIP — peer=0x%016llx sleeping", MS_ID, (unsigned long long)peer);
+            return 0;
+        }
+    }
+
     struct ms_session* s = _session_find(ms, peer, ns);
     DEBUG_TRACE(DEBUG_CATEGORY_MEMBER_SYNC, "%s: start peer=%016llx ns=%s new=%d", MS_ID, (unsigned long long)peer, ns, s ? 0 : 1);
     if (!s) {
@@ -939,3 +954,22 @@ void merkle_sync_cancel_ns(struct UTUN_INSTANCE* inst, const char* ns) {
     }
     if (removed) DEBUG_INFO(DEBUG_CATEGORY_MEMBER_SYNC, "%s: cancel_ns ns=%s removed=%d", MS_ID, ns, removed);
 }
+
+void merkle_sync_cancel_peer(struct UTUN_INSTANCE* inst, uint64_t peer) {
+    struct merkle_sync* ms = inst ? inst->msync : NULL;
+    if (!ms) return;
+    struct ms_session** p = &ms->sessions;
+    int removed = 0;
+    while (*p) {
+        struct ms_session* s = *p;
+        if (s->peer == peer) {
+            *p = s->next;
+            ms_session_outq_free(s);
+            u_free(s);
+            removed++;
+            continue;
+        }
+        p = &(*p)->next;
+    }
+    if (removed) DEBUG_INFO(DEBUG_CATEGORY_MEMBER_SYNC, "%s: cancel_peer peer=%016llx removed=%d", MS_ID, (unsigned long long)peer, removed);
+}
diff --git a/src/chat/merkle_sync.h b/src/chat/merkle_sync.h
index da4f33ff..2236bb7e 100644
--- a/src/chat/merkle_sync.h
+++ b/src/chat/merkle_sync.h
@@ -230,6 +230,12 @@ void merkle_sync_cancel(struct UTUN_INSTANCE* inst, uint64_t peer, const char* n
  */
 void merkle_sync_cancel_ns(struct UTUN_INSTANCE* inst, const char* ns);
 
+/*
+ * Отменить и удалить ВСЕ сессии с конкретным пиром peer (независимо от ns).
+ * Используется при уходе пира в спячку (server-side throttling). done_cb НЕ вызывается.
+ */
+void merkle_sync_cancel_peer(struct UTUN_INSTANCE* inst, uint64_t peer);
+
 /* ── Recompute tree path after data change ── */
 
 /*