diff --git a/auth_api_key/__init__.py b/auth_api_key/__init__.py
index 0650744f6b..5bf67492bc 100644
--- a/auth_api_key/__init__.py
+++ b/auth_api_key/__init__.py
@@ -1 +1,2 @@
 from . import models
+from .hooks import post_load_hook
diff --git a/auth_api_key/__manifest__.py b/auth_api_key/__manifest__.py
index ce16e39fb5..8cdfac8ae5 100644
--- a/auth_api_key/__manifest__.py
+++ b/auth_api_key/__manifest__.py
@@ -11,6 +11,7 @@
     "website": "https://github.com/OCA/server-auth",
     "development_status": "Production/Stable",
     "depends": ["base_setup"],
+    "post_load": "post_load_hook",
     "data": [
         "security/ir.model.access.csv",
         "views/auth_api_key.xml",
diff --git a/auth_api_key/hooks.py b/auth_api_key/hooks.py
new file mode 100644
index 0000000000..6fb64d994d
--- /dev/null
+++ b/auth_api_key/hooks.py
@@ -0,0 +1,52 @@
+# Copyright 2026 Camptocamp SA (https://www.camptocamp.com).
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
+
+from werkzeug.exceptions import HTTPException
+from werkzeug.wrappers import Response
+
+from odoo.http import Dispatcher
+
+
+def patch_dispatcher_pre_dispatch():
+    """Patch odoo.http.Dispatcher's pre_dispatch method.
+
+    For routes with cors enabled, Odoo will add a handler for the OPTIONS method,
+    which will raise an abort HTTPException with a 204 response describing the allowed
+    methods and headers in the Access-Control-* respnose headers.
+
+    For routes with api_key authentication, we must inform the client that the
+    API-KEY header is allowed.
+    """
+    original_pre_dispatch = Dispatcher.pre_dispatch
+
+    def pre_dispatch(self, rule, args):
+        get_header = self.request.future_response.headers.get
+        set_header = self.request.future_response.headers.set
+        routing = rule.endpoint.routing
+        if (
+            routing.get("cors")
+            and routing.get("auth") == "api_key"
+            and self.request.httprequest.method == "OPTIONS"
+        ):
+            try:
+                return original_pre_dispatch(self, rule, args)
+            except HTTPException as e:
+                if (
+                    isinstance(e.response, Response)
+                    and e.response.status_code == 204
+                    and get_header("Access-Control-Allow-Headers")
+                ):
+                    set_header(
+                        "Access-Control-Allow-Headers",
+                        f"{get_header('Access-Control-Allow-Headers')}, API-Key",
+                    )
+                raise
+        else:
+            return original_pre_dispatch(self, rule, args)
+
+    Dispatcher.pre_dispatch = pre_dispatch
+    Dispatcher.pre_dispatch._original_method = original_pre_dispatch
+
+
+def post_load_hook():
+    patch_dispatcher_pre_dispatch()
diff --git a/auth_api_key/tests/__init__.py b/auth_api_key/tests/__init__.py
index 56e3e32a3a..308b13b596 100644
--- a/auth_api_key/tests/__init__.py
+++ b/auth_api_key/tests/__init__.py
@@ -1 +1,2 @@
 from . import test_auth_api_key
+from . import test_controllers
diff --git a/auth_api_key/tests/test_controllers.py b/auth_api_key/tests/test_controllers.py
new file mode 100644
index 0000000000..b965d1b49e
--- /dev/null
+++ b/auth_api_key/tests/test_controllers.py
@@ -0,0 +1,57 @@
+# Copyright 2026 Camptocamp SA (https://www.camptocamp.com).
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
+
+import json
+
+from odoo.http import Controller, route
+from odoo.tests import HttpCase, new_test_user
+from odoo.tools import mute_logger
+
+
+class TestControllers(HttpCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.AuthApiKey = cls.env["auth.api.key"]
+        cls.test_user = new_test_user(
+            cls.env,
+            name="Test User",
+            login="test",
+            password="test",
+            email="test@test.com",
+            group_ids=[cls.env.ref("base.group_user").id],
+            company_id=cls.env.company.id,
+        )
+        cls.api_key = cls.AuthApiKey.create(
+            {"name": "good", "user_id": cls.test_user.id, "key": "api_key"}
+        )
+
+        class DummyController(Controller):
+            @route("/web/auth-api-key", type="http", auth="api_key", sitemap=False)
+            def auth_api_key(self, **params):
+                return json.dumps({"name": self.env.user.name})
+
+            @route("/web/auth-api-key-cors", type="http", auth="api_key", cors="*")
+            def auth_api_key_cors(self, **params):
+                return json.dumps({"name": self.env.user.name})
+
+        cls.env.registry.clear_cache("routing")
+        cls.addClassCleanup(cls.env.registry.clear_cache, "routing")
+
+    def test_auth_api_key_ok(self):
+        res = self.url_open("/web/auth-api-key", headers={"API-KEY": self.api_key.key})
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.json(), {"name": self.test_user.name})
+
+    @mute_logger("odoo.addons.base.models.ir_http")
+    def test_auth_api_key_wrong(self):
+        with self.assertLogs("odoo.http") as cm:
+            res = self.url_open("/web/auth-api-key", headers={"API-KEY": "wrong"})
+        self.assertEqual(res.status_code, 403)
+        self.assertIn("Access Denied", cm.output[0])
+
+    def test_auth_api_key_cors_options(self):
+        res = self.url_open("/web/auth-api-key-cors", method="OPTIONS")
+        self.assertEqual(res.status_code, 204)
+        self.assertEqual(res.headers["Access-Control-Allow-Origin"], "*")
+        self.assertIn("API-Key", res.headers["Access-Control-Allow-Headers"])