diff --git a/ChangeLog.adoc b/ChangeLog.adoc
index cc2181036..9ce6ed2cf 100644
--- a/ChangeLog.adoc
+++ b/ChangeLog.adoc
@@ -15,6 +15,7 @@ For a list of important changes that require manual actions, please look at rele
 
 New features::
 
+  * core: add unique identifier "id" in buffer (issue #2081)
   * core: add option `malloc_trim` in command `/sys`
   * core: add support of SGR mouse events (issue #2082)
   * core: reintroduce help on the variables and operators in `/help eval` (issue #2005)
diff --git a/doc/en/weechat_plugin_api.en.adoc b/doc/en/weechat_plugin_api.en.adoc
index 4ef7eb658..9a3b67636 100644
--- a/doc/en/weechat_plugin_api.en.adoc
+++ b/doc/en/weechat_plugin_api.en.adoc
@@ -14639,6 +14639,7 @@ Arguments:
 
 * _buffer_: buffer pointer
 * _property_: property name:
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _plugin_: name of plugin which created this buffer ("core" for WeeChat main buffer)
 ** _name_: name of buffer
 ** _full_name_: full name of buffer ("plugin.name") _(WeeChat ≥ 0.3.7)_
diff --git a/doc/fr/weechat_plugin_api.fr.adoc b/doc/fr/weechat_plugin_api.fr.adoc
index f8afcae20..18d18b049 100644
--- a/doc/fr/weechat_plugin_api.fr.adoc
+++ b/doc/fr/weechat_plugin_api.fr.adoc
@@ -14955,6 +14955,7 @@ Paramètres :
 
 * _buffer_ : pointeur vers le tampon
 * _property_ : nom de la propriété :
+** _id_ : identifiant unique _(WeeChat ≥ 4.3.0)_
 ** _plugin_ : nom de l'extension qui a créé ce tampon ("core" pour le tampon principal WeeChat)
 ** _name_ : nom du tampon
 ** _full_name_ : nom complet du tampon ("extension.nom") _(WeeChat ≥ 0.3.7)_
diff --git a/doc/it/weechat_plugin_api.it.adoc b/doc/it/weechat_plugin_api.it.adoc
index ac20083bc..ba611b731 100644
--- a/doc/it/weechat_plugin_api.it.adoc
+++ b/doc/it/weechat_plugin_api.it.adoc
@@ -15327,6 +15327,8 @@ Argomenti:
 
 * _buffer_: puntatore al buffer
 * _property_: nome proprietà:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _plugin_: nome del plugin che ha creato questo buffer ("core" per il buffer principale di WeeChat)
 ** _name_: nome del buffer
 ** _full_name_: nome completo del buffer ("plugin.nome") _(WeeChat ≥ 0.3.7)_
diff --git a/doc/ja/weechat_plugin_api.ja.adoc b/doc/ja/weechat_plugin_api.ja.adoc
index 3822fbb67..6c6461782 100644
--- a/doc/ja/weechat_plugin_api.ja.adoc
+++ b/doc/ja/weechat_plugin_api.ja.adoc
@@ -14861,6 +14861,8 @@ const char *weechat_buffer_get_string (struct t_gui_buffer *buffer,
 
 * _buffer_: バッファへのポインタ
 * _property_: プロパティ名:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _plugin_: バッファを作成したプラグインの名前 ("core" は WeeChat メインバッファ)
 ** _name_: バッファの名前
 ** _full_name_: バッファの完全な名前 ("plugin.name") _(WeeChat バージョン 0.3.7 以上で利用可)_
diff --git a/doc/sr/weechat_plugin_api.sr.adoc b/doc/sr/weechat_plugin_api.sr.adoc
index eae7b8cc4..10bf970a6 100644
--- a/doc/sr/weechat_plugin_api.sr.adoc
+++ b/doc/sr/weechat_plugin_api.sr.adoc
@@ -14222,6 +14222,8 @@ const char *weechat_buffer_get_string (struct t_gui_buffer *buffer,
 
 * _buffer_: показивач на бафер
 * _property_: име особине:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _plugin_: име додатка који је креирао овај бафер („core” за главни бафер програма WeeChat)
 ** _name_: име бафера
 ** _full_name_: пуно име бафера („додатак.име”) _(WeeChat ≥ 0.3.7)_
diff --git a/src/core/wee-upgrade.c b/src/core/wee-upgrade.c
index 91920f37d..05c1b9a50 100644
--- a/src/core/wee-upgrade.c
+++ b/src/core/wee-upgrade.c
@@ -405,10 +405,27 @@ void
 upgrade_weechat_read_buffer (struct t_infolist *infolist)
 {
     struct t_gui_buffer *ptr_buffer;
-    const char *key, *var_name, *name, *plugin_name;
+    const char *key, *var_name, *name, *plugin_name, *ptr_id;
     const char *str;
-    char option_name[64], *option_key, *option_var;
+    char option_name[64], *option_key, *option_var, *error;
     int index, length, main_buffer;
+    long long id;
+
+    /* "id" is new in WeeChat 4.3.0 */
+    id = -1;
+    if (infolist_search_var (infolist, "id"))
+    {
+        ptr_id = infolist_string (infolist, "id");
+        if (ptr_id)
+        {
+            error = NULL;
+            id = strtoll (ptr_id, &error, 10);
+            if (!error || error[0])
+                id = -1;
+        }
+    }
+    if (id < 0)
+        id = gui_buffer_generate_id ();
 
     plugin_name = infolist_string (infolist, "plugin_name");
     name = infolist_string (infolist, "name");
@@ -420,19 +437,25 @@ upgrade_weechat_read_buffer (struct t_infolist *infolist)
     {
         /* use WeeChat main buffer */
         upgrade_current_buffer = gui_buffers;
+        upgrade_current_buffer->id = id;
     }
     else
     {
         /* create buffer it it's not main buffer */
-        upgrade_current_buffer = gui_buffer_new (NULL,
-                                                 infolist_string (infolist,
-                                                                  "name"),
-                                                 NULL, NULL, NULL,
-                                                 NULL, NULL, NULL);
+        upgrade_current_buffer = gui_buffer_new_props_with_id (
+            id,
+            NULL,  /* plugin */
+            infolist_string (infolist, "name"),
+            NULL,  /* properties */
+            NULL, NULL, NULL,  /* input callback */
+            NULL, NULL, NULL);  /* close callback */
     }
     if (!upgrade_current_buffer)
         return;
 
+    if (upgrade_current_buffer->id > gui_buffer_last_id_assigned)
+        gui_buffer_last_id_assigned = upgrade_current_buffer->id;
+
     ptr_buffer = upgrade_current_buffer;
 
     if (infolist_integer (infolist, "current_buffer"))
@@ -799,6 +822,8 @@ upgrade_weechat_read_cb (const void *pointer, void *data,
     (void) data;
     (void) upgrade_file;
 
+    gui_buffer_last_id_assigned = -1;
+
     infolist_reset_item_cursor (infolist);
     while (infolist_next (infolist))
     {
diff --git a/src/gui/gui-buffer.c b/src/gui/gui-buffer.c
index 3da3088b5..8ad9949a0 100644
--- a/src/gui/gui-buffer.c
+++ b/src/gui/gui-buffer.c
@@ -32,6 +32,7 @@
 #include <string.h>
 #include <signal.h>
 #include <time.h>
+#include <sys/time.h>
 #include <ctype.h>
 
 #include "../core/weechat.h"
@@ -75,6 +76,8 @@ int gui_buffers_visited_count = 0;              /* number of visited buffers*/
 int gui_buffers_visited_frozen = 0;             /* 1 to forbid list updates */
 struct t_gui_buffer *gui_buffer_last_displayed = NULL; /* last b. displayed */
 
+long long gui_buffer_last_id_assigned = -1;      /* last id assigned         */
+
 char *gui_buffer_reserved_names[] =
 { GUI_BUFFER_MAIN, SECURE_BUFFER_NAME, GUI_COLOR_BUFFER_NAME,
   NULL
@@ -106,7 +109,7 @@ char *gui_buffer_properties_get_integer[] =
   NULL
 };
 char *gui_buffer_properties_get_string[] =
-{ "plugin", "name", "full_name", "old_full_name", "short_name", "title",
+{ "id", "plugin", "name", "full_name", "old_full_name", "short_name", "title",
   "input", "text_search_input", "highlight_words", "highlight_disable_regex",
   "highlight_regex", "highlight_tags_restrict", "highlight_tags",
   "hotlist_max_level_nicks",
@@ -605,6 +608,34 @@ gui_buffer_insert (struct t_gui_buffer *buffer)
     }
 }
 
+/*
+ * Returns a new unique id for a buffer.
+ *
+ * The id is the current time with microseconds precision.
+ * The same time (including microseconds) can be used only one time, so that
+ * all buffer ids are guaranteed to be unique.
+ */
+
+long long
+gui_buffer_generate_id ()
+{
+    struct timeval tv;
+    long long id;
+
+    gettimeofday (&tv, NULL);
+
+    id = ((long long)tv.tv_sec * 1000000LL) + (long long)(tv.tv_usec);
+
+    /*
+     * ensure we never use the same id for two buffers and that the returned
+     * id is strictly greater than the last assigned one
+     */
+    if (id <= gui_buffer_last_id_assigned)
+        id = gui_buffer_last_id_assigned + 1;
+
+    return id;
+}
+
 /*
  * Initializes input_buffer_* variables in a buffer.
  */
@@ -746,26 +777,28 @@ gui_buffer_apply_config_properties (struct t_gui_buffer *buffer)
 }
 
 /*
- * Creates a new buffer in current window with some optional properties.
+ * Creates a new buffer in current window with some optional properties,
+ * using id (this function is for internal use only).
  *
  * Returns pointer to new buffer, NULL if error.
  */
 
 struct t_gui_buffer *
-gui_buffer_new_props (struct t_weechat_plugin *plugin,
-                      const char *name,
-                      struct t_hashtable *properties,
-                      int (*input_callback)(const void *pointer,
-                                            void *data,
-                                            struct t_gui_buffer *buffer,
-                                            const char *input_data),
-                      const void *input_callback_pointer,
-                      void *input_callback_data,
-                      int (*close_callback)(const void *pointer,
-                                            void *data,
-                                            struct t_gui_buffer *buffer),
-                      const void *close_callback_pointer,
-                      void *close_callback_data)
+gui_buffer_new_props_with_id (long long id,
+                              struct t_weechat_plugin *plugin,
+                              const char *name,
+                              struct t_hashtable *properties,
+                              int (*input_callback)(const void *pointer,
+                                                    void *data,
+                                                    struct t_gui_buffer *buffer,
+                                                    const char *input_data),
+                              const void *input_callback_pointer,
+                              void *input_callback_data,
+                              int (*close_callback)(const void *pointer,
+                                                    void *data,
+                                                    struct t_gui_buffer *buffer),
+                              const void *close_callback_pointer,
+                              void *close_callback_data)
 {
     struct t_gui_buffer *new_buffer;
     int first_buffer_creation;
@@ -797,6 +830,9 @@ gui_buffer_new_props (struct t_weechat_plugin *plugin,
         return NULL;
 
     /* init buffer */
+    new_buffer->id = id;
+    if (new_buffer->id > gui_buffer_last_id_assigned)
+        gui_buffer_last_id_assigned = new_buffer->id;
     new_buffer->opening = 1;
     new_buffer->plugin = plugin;
     new_buffer->plugin_name_for_upgrade = NULL;
@@ -971,6 +1007,41 @@ gui_buffer_new_props (struct t_weechat_plugin *plugin,
     return new_buffer;
 }
 
+/*
+ * Creates a new buffer in current window with some optional properties.
+ *
+ * Returns pointer to new buffer, NULL if error.
+ */
+
+struct t_gui_buffer *
+gui_buffer_new_props (struct t_weechat_plugin *plugin,
+                      const char *name,
+                      struct t_hashtable *properties,
+                      int (*input_callback)(const void *pointer,
+                                            void *data,
+                                            struct t_gui_buffer *buffer,
+                                            const char *input_data),
+                      const void *input_callback_pointer,
+                      void *input_callback_data,
+                      int (*close_callback)(const void *pointer,
+                                            void *data,
+                                            struct t_gui_buffer *buffer),
+                      const void *close_callback_pointer,
+                      void *close_callback_data)
+{
+    return gui_buffer_new_props_with_id (
+        gui_buffer_generate_id (),
+        plugin,
+        name,
+        properties,
+        input_callback,
+        input_callback_pointer,
+        input_callback_data,
+        close_callback,
+        close_callback_pointer,
+        close_callback_data);
+}
+
 /*
  * Creates a new buffer in current window.
  *
@@ -1441,11 +1512,17 @@ const char *
 gui_buffer_get_string (struct t_gui_buffer *buffer, const char *property)
 {
     const char *ptr_value;
+    static char str_value[64];
 
     if (!buffer || !property)
         return NULL;
 
-    if (strcmp (property, "plugin") == 0)
+    if (strcmp (property, "id") == 0)
+    {
+        snprintf (str_value, sizeof (str_value), "%lld", buffer->id);
+        return str_value;
+    }
+    else if (strcmp (property, "plugin") == 0)
         return gui_buffer_get_plugin_name (buffer);
     else if (strcmp (property, "name") == 0)
         return buffer->name;
@@ -5012,6 +5089,7 @@ gui_buffer_hdata_buffer_cb (const void *pointer, void *data,
                        0, 0, NULL, NULL);
     if (hdata)
     {
+        HDATA_VAR(struct t_gui_buffer, id, LONGLONG, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, opening, INTEGER, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, plugin, POINTER, 0, NULL, "plugin");
         HDATA_VAR(struct t_gui_buffer, plugin_name_for_upgrade, STRING, 0, NULL, NULL);
@@ -5183,7 +5261,7 @@ gui_buffer_add_to_infolist (struct t_infolist *infolist,
 {
     struct t_infolist_item *ptr_item;
     struct t_gui_key *ptr_key;
-    char option_name[64];
+    char option_name[64], str_value[64];
     int i;
 
     if (!infolist || !buffer)
@@ -5198,6 +5276,9 @@ gui_buffer_add_to_infolist (struct t_infolist *infolist,
     if (!infolist_new_var_integer (ptr_item, "current_buffer",
                                    (gui_current_window->buffer == buffer) ? 1 : 0))
         return 0;
+    snprintf (str_value, sizeof (str_value), "%lld", buffer->id);
+    if (!infolist_new_var_string (ptr_item, "id", str_value))
+        return 0;
     if (!infolist_new_var_integer (ptr_item, "opening", buffer->opening))
         return 0;
     if (!infolist_new_var_pointer (ptr_item, "plugin", buffer->plugin))
@@ -5457,6 +5538,7 @@ gui_buffer_print_log ()
     {
         log_printf ("");
         log_printf ("[buffer (addr:0x%lx)]", ptr_buffer);
+        log_printf ("  id. . . . . . . . . . . : %lld",  ptr_buffer->id);
         log_printf ("  opening . . . . . . . . : %d",    ptr_buffer->opening);
         log_printf ("  plugin. . . . . . . . . : 0x%lx ('%s')",
                     ptr_buffer->plugin, gui_buffer_get_plugin_name (ptr_buffer));
diff --git a/src/gui/gui-buffer.h b/src/gui/gui-buffer.h
index c97947e72..b8a20e301 100644
--- a/src/gui/gui-buffer.h
+++ b/src/gui/gui-buffer.h
@@ -98,6 +98,8 @@ struct t_gui_input_undo
 
 struct t_gui_buffer
 {
+    long long id;                      /* unique id for buffer              */
+                                       /* (timestamp with microseconds)     */
     int opening;                       /* 1 if buffer is being opened       */
     struct t_weechat_plugin *plugin;   /* plugin which created this buffer  */
                                        /* (NULL for a WeeChat buffer)       */
@@ -276,6 +278,7 @@ extern int gui_buffers_visited_index;
 extern int gui_buffers_visited_count;
 extern int gui_buffers_visited_frozen;
 extern struct t_gui_buffer *gui_buffer_last_displayed;
+extern long long gui_buffer_last_id_assigned;
 extern char *gui_buffer_reserved_names[];
 extern char *gui_buffer_type_string[];
 extern char *gui_buffer_notify_string[];
@@ -300,9 +303,25 @@ extern void gui_buffer_local_var_add (struct t_gui_buffer *buffer,
 extern void gui_buffer_local_var_remove (struct t_gui_buffer *buffer,
                                          const char *name);
 extern void gui_buffer_notify_set_all ();
+extern long long gui_buffer_generate_id ();
 extern int gui_buffer_is_reserved_name (const char *name);
 extern void gui_buffer_apply_config_option_property (struct t_gui_buffer *buffer,
                                                      struct t_config_option *option);
+extern struct t_gui_buffer *gui_buffer_new_props_with_id (long long id,
+                                                          struct t_weechat_plugin *plugin,
+                                                          const char *name,
+                                                          struct t_hashtable *properties,
+                                                          int (*input_callback)(const void *pointer,
+                                                                                void *data,
+                                                                                struct t_gui_buffer *buffer,
+                                                                                const char *input_data),
+                                                          const void *input_callback_pointer,
+                                                          void *input_callback_data,
+                                                          int (*close_callback)(const void *pointer,
+                                                                                void *data,
+                                                                                struct t_gui_buffer *buffer),
+                                                          const void *close_callback_pointer,
+                                                          void *close_callback_data);
 extern struct t_gui_buffer *gui_buffer_new_props (struct t_weechat_plugin *plugin,
                                                   const char *name,
                                                   struct t_hashtable *properties,
diff --git a/tests/scripts/python/testapi.py b/tests/scripts/python/testapi.py
index de3023bb3..920b8ddc3 100644
--- a/tests/scripts/python/testapi.py
+++ b/tests/scripts/python/testapi.py
@@ -705,7 +705,7 @@ def test_hdata():
     line2 = weechat.hdata_pointer(hdata_line, line1, 'next_line')
     line3 = weechat.hdata_pointer(hdata_line, line2, 'next_line')
     # hdata_get_var_offset
-    check(weechat.hdata_get_var_offset(hdata_buffer, 'opening') == 0)
+    check(weechat.hdata_get_var_offset(hdata_buffer, 'id') == 0)
     check(weechat.hdata_get_var_offset(hdata_buffer, 'plugin') > 0)
     # hdata_get_var_type_string
     check(weechat.hdata_get_var_type_string(hdata_buffer, 'plugin') == 'pointer')
@@ -751,6 +751,8 @@ def test_hdata():
     weechat.buffer_set(buffer, 'hotlist', weechat.WEECHAT_HOTLIST_MESSAGE)
     gui_hotlist = weechat.hdata_get_list(hdata_hotlist, 'gui_hotlist')
     check(weechat.hdata_long(hdata_hotlist, gui_hotlist, 'creation_time.tv_usec') >= 0)
+    # hdata_longlong
+    check(weechat.hdata_longlong(hdata_buffer, buffer2, 'id') > 1708874542000000)
     # hdata_string
     check(weechat.hdata_string(hdata_buffer, buffer2, 'name') == 'test')
     # hdata_pointer
diff --git a/tests/unit/gui/test-gui-buffer.cpp b/tests/unit/gui/test-gui-buffer.cpp
index 66a219c66..b61dc1352 100644
--- a/tests/unit/gui/test-gui-buffer.cpp
+++ b/tests/unit/gui/test-gui-buffer.cpp
@@ -383,6 +383,23 @@ TEST(GuiBuffer, Insert)
     /* TODO: write tests */
 }
 
+/*
+ * Tests functions:
+ *   gui_buffer_generate_id
+ */
+
+TEST(GuiBuffer, GenerateId)
+{
+    long long id;
+
+    id = gui_buffer_generate_id ();
+    CHECK(id > gui_buffer_last_id_assigned);
+    id = gui_buffer_generate_id ();
+    CHECK(id > gui_buffer_last_id_assigned);
+    id = gui_buffer_generate_id ();
+    CHECK(id > gui_buffer_last_id_assigned);
+}
+
 /*
  * Tests functions:
  *   gui_buffer_input_buffer_init
@@ -492,6 +509,7 @@ test_buffer_close_cb (const void *pointer, void *data,
 
 /*
  * Tests functions:
+ *   gui_buffer_new_props_with_id
  *   gui_buffer_new_props
  */