diff --git a/addons/cetmix_tower_server/tests/test_partner_server_btn.py b/addons/cetmix_tower_server/tests/test_partner_server_btn.py
new file mode 100644
index 0000000..fcfb2dd
--- /dev/null
+++ b/addons/cetmix_tower_server/tests/test_partner_server_btn.py
@@ -0,0 +1,58 @@
+# Copyright (C) 2022 Cetmix OÜ
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo.tests.common import tagged
+
+from .common import TestTowerCommon
+
+
+@tagged("partner_servers_btn")
+class TestPartnerServers(TestTowerCommon):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.partner_a = cls.env["res.partner"].create({"name": "Partner A"})
+        cls.partner_b = cls.env["res.partner"].create({"name": "Partner B"})
+        cls.partner_b_child = cls.env["res.partner"].create(
+            {
+                "name": "Partner B Child",
+                "parent_id": cls.partner_b.id,
+            }
+        )
+
+        cls.server_defaults = {
+            "name": "Test Server",
+            "ssh_username": "root",
+            "ssh_port": 22,
+            "ssh_password": "Test-P@ssw0rd-123",
+            "ip_v4_address": "127.0.0.1",
+            "skip_host_key": True,
+        }
+
+        cls.Server.create({"partner_id": cls.partner_b.id, **cls.server_defaults})
+        cls.Server.create({"partner_id": cls.partner_b.id, **cls.server_defaults})
+        cls.Server.create({"partner_id": cls.partner_b_child.id, **cls.server_defaults})
+
+        key = cls.Key.create({"name": "SSH Token", "key_type": "s"})
+        cls.KeyValue.create(
+            {
+                "key_id": key.id,
+                "partner_id": cls.partner_b.id,
+                "secret_value": "TOPSECRET",
+            }
+        )
+
+    def test_server_count_compute(self):
+        """Server count: direct + one‑level child + zero if none."""
+        self.assertEqual(self.partner_b.server_count, 3)
+        self.assertEqual(self.partner_b_child.server_count, 1)
+        self.assertEqual(self.partner_a.server_count, 0)
+
+    def test_parent_with_only_child_servers(self):
+        """Parent without servers directs and with child_of."""
+        parent = self.env["res.partner"].create({"name": "Parent Only"})
+        child = self.env["res.partner"].create(
+            {"name": "Child with Server", "parent_id": parent.id}
+        )
+        self.Server.create({"partner_id": child.id, **self.server_defaults})
+        self.assertEqual(parent.server_count, 1)