diff --git a/src/backend/x11/backend.c b/src/backend/x11/backend.c
index d1629e5..a56c3e5 100644
--- a/src/backend/x11/backend.c
+++ b/src/backend/x11/backend.c
@@ -19,6 +19,7 @@
 
 #include "backend/output_utils.h"
 #include "backend/x11/cursor.h"
+#include "backend/x11/tray.h"
 #include "backend/x11/window.h"
 #include "base/app.h"
 #include "base/array.h"
@@ -845,6 +846,8 @@ backend_bar_window_t backend_create_bar_window(
     fatal("cannot create cairo context: %s", cairo_status_to_string(statue));
   }
 
+  if (enable_tray) tray_init(backend, window_id, width, height);
+
   return (backend_bar_window_t){
     .window_id = window_id,
     .cr = cr,
diff --git a/src/backend/x11/internal.h b/src/backend/x11/internal.h
index db04315..ae5cad1 100644
--- a/src/backend/x11/internal.h
+++ b/src/backend/x11/internal.h
@@ -9,7 +9,6 @@
 
 #include "common/window.h"
 #include "interface/event.h"
-#include "interface/tray.h"
 
 #define EWMH_ATOMS(X)                  \
   X(_NET_WM_NAME)                      \
@@ -87,17 +86,7 @@ typedef enum cursor_t {
   ZDWM_CURSOR_COUNT,
 } cursor_t;
 
-typedef struct tray_host_t {
-  bool enabled;
-  xcb_window_t host_window;
-  xcb_window_t container;
-  int32_t icon_size;
-  size_t icon_count;
-  tray_icons_change_cb_t icon_change_cb;
-  void *cb_user_data;
-} tray_host_t;
-
-extern const tray_api_t tray_api;
+typedef struct tray_host_t tray_host_t;
 
 typedef struct backend_t {
   xcb_key_symbols_t *key_symbols;
@@ -123,7 +112,7 @@ typedef struct backend_t {
   window_list_t map;
   window_list_t kill;
 
-  tray_host_t tray;
+  tray_host_t *tray;
 } backend_t;
 
 bool populate_window_event(
diff --git a/src/backend/x11/tray.c b/src/backend/x11/tray.c
index c1633e0..1748675 100644
--- a/src/backend/x11/tray.c
+++ b/src/backend/x11/tray.c
@@ -1,41 +1,66 @@
-#include "interface/tray.h"
+#include "backend/x11/tray.h"
 
 #include <stddef.h>
 #include <stdint.h>
+#include <stdio.h>
+#include <xcb/xcb.h>
+#include <xcb/xproto.h>
 #include <zdwm/types.h>
 
+#include "backend/x11/window.h"
+#include "base/log.h"
+#include "base/macros.h"
+#include "base/memory.h"
+#include "interface/tray.h"
 #include "interface/types.h"
 #include "internal.h"
 
-static window_id_t tray_host_window(void *handle) {
-  backend_t *backend = handle;
-  if (backend == nullptr || !backend->tray.enabled) {
-    return ZDWM_WINDOW_ID_INVALID;
-  }
+typedef struct tray_host_t {
+  bool enabled;
+  bool initialized;
+  xcb_atom_t selection_atom;
+  xcb_window_t host_window;
+  xcb_window_t container;
+  int32_t icon_size;
+  size_t icon_count;
+  tray_icons_change_cb_t icon_change_cb;
+  void *cb_user_data;
+} tray_host_t;
 
-  return backend->tray.host_window;
+static tray_host_t *get_tray_host(void *handle) {
+  backend_t *backend = handle;
+  if (!backend) return nullptr;
+
+  auto tray = backend->tray;
+  if (!tray || !tray->enabled) return nullptr;
+
+  return tray;
+}
+
+static window_id_t tray_host_window(void *handle) {
+  auto tray = get_tray_host(handle);
+  if (!tray) return ZDWM_WINDOW_ID_INVALID;
+
+  return tray->host_window;
 }
 
 static size_t tray_icon_count(void *handle) {
-  backend_t *backend = handle;
-  if (backend == nullptr || !backend->tray.enabled) return 0;
+  auto tray = get_tray_host(handle);
 
-  return backend->tray.icon_count;
+  return tray ? tray->icon_count : 0;
 }
 
 static int32_t tray_icon_size(void *handle) {
-  backend_t *backend = handle;
-  if (backend == nullptr || !backend->tray.enabled) return 0;
+  auto tray = get_tray_host(handle);
 
-  return backend->tray.icon_size;
+  return tray ? tray->icon_size : 0;
 }
 
 static void tray_place(void *handle, int32_t x) {
-  backend_t *backend = handle;
-  if (backend == nullptr || !backend->tray.enabled) return;
+  auto tray = get_tray_host(handle);
+  if (!tray) return;
 
-  auto conn = backend->conn;
-  auto tray = &backend->tray;
+  auto conn = ((backend_t *)handle)->conn;
   uint16_t value_mask = XCB_CONFIG_WINDOW_X;
   xcb_configure_window_value_list_t value_list = {.x = x};
   xcb_configure_window_aux(conn, tray->container, value_mask, &value_list);
@@ -43,11 +68,11 @@ static void tray_place(void *handle, int32_t x) {
 
 static void
 tray_set_listeners(void *handle, tray_icons_change_cb_t cb, void *user_data) {
-  backend_t *backend = handle;
-  if (backend == nullptr) return;
+  auto tray = get_tray_host(handle);
+  if (!tray) return;
 
-  backend->tray.icon_change_cb = cb;
-  backend->tray.cb_user_data = user_data;
+  tray->icon_change_cb = cb;
+  tray->cb_user_data = user_data;
 }
 
 const tray_api_t tray_api = {
@@ -57,3 +82,142 @@ const tray_api_t tray_api = {
   .place = tray_place,
   .set_listener = tray_set_listeners,
 };
+
+static bool tray_intern_selection_atom(tray_host_t *tray, backend_t *backend) {
+  auto conn = backend->conn;
+  auto screenp = backend->screenp;
+
+  char selection_name[64] = {0};
+  auto atom_name_format = "_NET_SYSTEM_TRAY_S%d";
+  snprintf(selection_name, sizeof(selection_name), atom_name_format, screenp);
+
+  uint16_t name_length = strlen(selection_name);
+  auto cookie = xcb_intern_atom(conn, false, name_length, selection_name);
+  auto reply = xcb_intern_atom_reply(conn, cookie, nullptr);
+  if (!reply) {
+    warn("cannot intern tray selection atom: %s", selection_name);
+    return false;
+  }
+
+  tray->selection_atom = reply->atom;
+  p_delete(&reply);
+  return true;
+}
+
+typedef struct tray_host_window_t {
+  xcb_window_t window;
+  int32_t width;
+  int32_t height;
+} tray_host_window_t;
+
+static bool tray_create_container_window(
+  tray_host_t *tray,
+  backend_t *backend,
+  tray_host_window_t host_window
+) {
+  auto conn = backend->conn;
+  auto window_id = xcb_generate_id(conn);
+
+  xcb_create_window_value_list_t value_list = {
+    .override_redirect = true,
+    .event_mask =
+      XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_STRUCTURE_NOTIFY
+  };
+  auto cookie = xcb_create_window_aux_checked(
+    conn,
+    XCB_COPY_FROM_PARENT,
+    window_id,
+    host_window.window,
+    (int16_t)host_window.width,
+    0,
+    1,
+    (uint16_t)MAX(1, host_window.height),
+    0,
+    XCB_WINDOW_CLASS_INPUT_OUTPUT,
+    XCB_COPY_FROM_PARENT,
+    XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK,
+    &value_list
+  );
+
+  if (xcb_request_check(conn, cookie)) {
+    warn("cannot create system tray container window: 0x%x", window_id);
+    return false;
+  }
+
+  tray->container = window_id;
+
+  window_set_class_instance(conn, window_id);
+
+#define TRAY_CONTAINER_WINDOW_NAME APP_NAME "_tray"
+  window_set_name_static(conn, window_id, TRAY_CONTAINER_WINDOW_NAME);
+  auto name = TRAY_CONTAINER_WINDOW_NAME;
+  auto name_len = sizeof(TRAY_CONTAINER_WINDOW_NAME) - 1;
+#undef TRAY_CONTAINER_WINDOW_NAME
+
+  uint8_t mode = XCB_PROP_MODE_REPLACE;
+  auto atoms = &backend->atoms;
+  auto prop = atoms->_NET_WM_NAME;
+  auto type = atoms->UTF8_STRING;
+  xcb_change_property(conn, mode, window_id, prop, type, 8, name_len, name);
+
+  return true;
+}
+
+static bool tray_take_selection_owner(tray_host_t *tray, backend_t *backend) {
+  auto conn = backend->conn;
+  auto atom = tray->selection_atom;
+  auto cookie = xcb_get_selection_owner(conn, atom);
+  auto reply = xcb_get_selection_owner_reply(conn, cookie, nullptr);
+  if (reply && reply->owner != XCB_WINDOW_NONE) {
+    warn(
+      "system tray selection is already owned by window: 0x%x",
+      reply->owner
+    );
+    p_delete(&reply);
+    return false;
+  }
+
+  p_delete(&reply);
+
+  auto owner = tray->container;
+  xcb_set_selection_owner(conn, owner, atom, XCB_CURRENT_TIME);
+
+  cookie = xcb_get_selection_owner(conn, atom);
+  reply = xcb_get_selection_owner_reply(conn, cookie, nullptr);
+  bool success = reply && reply->owner == owner;
+  p_delete(&reply);
+
+  if (!success) warn("cannot acquire system tray selection");
+  return success;
+}
+
+void tray_init(
+  backend_t *backend,
+  xcb_window_t host_window,
+  int32_t host_width,
+  int32_t host_height
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray) {
+    tray = p_new(tray_host_t, 1);
+    backend->tray = tray;
+  }
+
+  if (tray->initialized) return;
+
+  if (!tray_intern_selection_atom(tray, backend)) return;
+
+  tray_host_window_t host_window_params = {
+    .window = host_window,
+    .width = host_width,
+    .height = host_height
+  };
+  if (!tray_create_container_window(tray, backend, host_window_params)) return;
+  if (!tray_take_selection_owner(tray, backend)) {
+    /* TODO: cleanup tray */
+    return;
+  }
+
+  tray->enabled = true;
+  tray->initialized = true;
+}
diff --git a/src/backend/x11/tray.h b/src/backend/x11/tray.h
new file mode 100644
index 0000000..4df0025
--- /dev/null
+++ b/src/backend/x11/tray.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <stdint.h>
+#include <xcb/xproto.h>
+
+#include "interface/tray.h"
+
+extern const tray_api_t tray_api;
+
+typedef struct backend_t backend_t;
+
+void tray_init(
+  backend_t *backend,
+  xcb_window_t host_window,
+  int32_t host_width,
+  int32_t host_height
+);