diff --git a/.gitreview b/.gitreview
index 4eee726db..ae16227da 100644
--- a/.gitreview
+++ b/.gitreview
@@ -2,3 +2,4 @@
 host=review.opendev.org
 port=29418
 project=openstack/python-openstackclient.git
+defaultbranch=stable/2026.1
diff --git a/openstackclient/identity/v3/project.py b/openstackclient/identity/v3/project.py
index 99242391f..f3d7fea23 100644
--- a/openstackclient/identity/v3/project.py
+++ b/openstackclient/identity/v3/project.py
@@ -342,21 +342,21 @@ def take_action(self, parsed_args):
             user = self.app.client_manager.auth_ref.user_id
 
         if user:
-            data = identity_client.user_projects(user, **kwargs)
+            data = list(identity_client.user_projects(user, **kwargs))
         else:
             try:
-                data = identity_client.projects(**kwargs)
+                data = list(identity_client.projects(**kwargs))
             except sdk_exc.ForbiddenException:
                 # NOTE(adriant): if no filters, assume a forbidden is non-admin
                 # wanting their own project list.
                 if not kwargs:
                     user = self.app.client_manager.auth_ref.user_id
-                    data = identity_client.user_projects(user)
+                    data = list(identity_client.user_projects(user))
                 else:
                     raise
 
         if parsed_args.sort:
-            data = utils.sort_items(data, parsed_args.sort)
+            data = list(utils.sort_items(data, parsed_args.sort))
 
         return (
             column_headers,
diff --git a/openstackclient/tests/functional/common/test_extension.py b/openstackclient/tests/functional/common/test_extension.py
index c65f52db5..1a8af9bc8 100644
--- a/openstackclient/tests/functional/common/test_extension.py
+++ b/openstackclient/tests/functional/common/test_extension.py
@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
+
 from tempest.lib import exceptions as tempest_exc
 
 from openstackclient.tests.functional import base
@@ -21,6 +23,8 @@
 class ExtensionTests(base.TestCase):
     """Functional tests for extension"""
 
+    haz_network: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/common/test_quota.py b/openstackclient/tests/functional/common/test_quota.py
index 373b178c1..a9bcaec74 100644
--- a/openstackclient/tests/functional/common/test_quota.py
+++ b/openstackclient/tests/functional/common/test_quota.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from tempest.lib.common.utils import data_utils
@@ -25,7 +26,8 @@ class QuotaTests(base.TestCase):
     test runs as these may run in parallel and otherwise step on each other.
     """
 
-    PROJECT_NAME: str
+    haz_network: ClassVar[bool]
+    PROJECT_NAME: ClassVar[str]
 
     @classmethod
     def setUpClass(cls):
diff --git a/openstackclient/tests/functional/compute/v2/test_flavor.py b/openstackclient/tests/functional/compute/v2/test_flavor.py
index 4a0ff4883..7f4cc43e7 100644
--- a/openstackclient/tests/functional/compute/v2/test_flavor.py
+++ b/openstackclient/tests/functional/compute/v2/test_flavor.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional import base
@@ -19,6 +20,7 @@ class FlavorTests(base.TestCase):
     """Functional tests for flavor."""
 
     PROJECT_NAME = uuid.uuid4().hex
+    PROJECT_ID: ClassVar[str]
 
     @classmethod
     def setUpClass(cls):
@@ -28,7 +30,7 @@ def setUpClass(cls):
             "project create --enable " + cls.PROJECT_NAME,
             parse_output=True,
         )
-        cls.project_id = cmd_output["id"]
+        cls.PROJECT_ID = cmd_output["id"]
 
     @classmethod
     def tearDownClass(cls):
diff --git a/openstackclient/tests/functional/compute/v2/test_server.py b/openstackclient/tests/functional/compute/v2/test_server.py
index 6afa2c7c0..c00d9dc55 100644
--- a/openstackclient/tests/functional/compute/v2/test_server.py
+++ b/openstackclient/tests/functional/compute/v2/test_server.py
@@ -13,6 +13,7 @@
 import itertools
 import json
 import time
+from typing import ClassVar
 import uuid
 
 from tempest.lib import exceptions
@@ -25,6 +26,8 @@
 class ServerTests(common.ComputeTestCase):
     """Functional tests for openstack server commands"""
 
+    haz_network: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/identity/v2/common.py b/openstackclient/tests/functional/identity/v2/common.py
index dd2e27193..34962e6fe 100644
--- a/openstackclient/tests/functional/identity/v2/common.py
+++ b/openstackclient/tests/functional/identity/v2/common.py
@@ -11,6 +11,7 @@
 #    under the License.
 
 import os
+from typing import ClassVar
 import unittest
 
 import fixtures
@@ -57,6 +58,9 @@ class IdentityTests(base.TestCase):
     CATALOG_LIST_HEADERS = ['Name', 'Type', 'Endpoints']
     ENDPOINT_LIST_HEADERS = ['ID', 'Region', 'Service Name', 'Service Type']
 
+    project_name: ClassVar[str]
+    project_description: ClassVar[str]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/identity/v3/common.py b/openstackclient/tests/functional/identity/v3/common.py
index 9f21374ff..8089e1d04 100644
--- a/openstackclient/tests/functional/identity/v3/common.py
+++ b/openstackclient/tests/functional/identity/v3/common.py
@@ -11,6 +11,7 @@
 #    under the License.
 
 import os
+from typing import ClassVar
 
 import fixtures
 from tempest.lib.common.utils import data_utils
@@ -147,6 +148,11 @@ class IdentityTests(base.TestCase):
         'Region ID',
     ]
 
+    domain_name: ClassVar[str]
+    domain_description: ClassVar[str]
+    project_name: ClassVar[str]
+    project_description: ClassVar[str]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/image/base.py b/openstackclient/tests/functional/image/base.py
index d948f8155..e11093f38 100644
--- a/openstackclient/tests/functional/image/base.py
+++ b/openstackclient/tests/functional/image/base.py
@@ -10,12 +10,18 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
+
 from openstackclient.tests.functional import base
 
 
 class BaseImageTests(base.TestCase):
     """Functional tests for Image commands"""
 
+    # TODO(stephenfin): Nothing sets this to true any more. We should remove it
+    # along with any dependent tests.
+    haz_v1_api: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/network/v2/common.py b/openstackclient/tests/functional/network/v2/common.py
index 248758a84..6d7272493 100644
--- a/openstackclient/tests/functional/network/v2/common.py
+++ b/openstackclient/tests/functional/network/v2/common.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional import base
@@ -18,6 +19,8 @@
 class NetworkTests(base.TestCase):
     """Functional tests for Network commands"""
 
+    haz_network: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
@@ -33,7 +36,7 @@ def setUp(self):
 class NetworkTagTests(NetworkTests):
     """Functional tests with tag operation"""
 
-    base_command: str
+    base_command: ClassVar[str]
 
     def test_tag_operation(self):
         # Get project IDs
diff --git a/openstackclient/tests/functional/network/v2/test_floating_ip.py b/openstackclient/tests/functional/network/v2/test_floating_ip.py
index a1b11a44a..e34fe552c 100644
--- a/openstackclient/tests/functional/network/v2/test_floating_ip.py
+++ b/openstackclient/tests/functional/network/v2/test_floating_ip.py
@@ -11,6 +11,7 @@
 #    under the License.
 
 import random
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional.network.v2 import common
@@ -19,6 +20,11 @@
 class FloatingIpTests(common.NetworkTests):
     """Functional tests for floating ip"""
 
+    EXTERNAL_NETWORK_NAME: ClassVar[str]
+    PRIVATE_NETWORK_NAME: ClassVar[str]
+    external_network_id: ClassVar[str]
+    private_network_id: ClassVar[str]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/network/v2/test_ip_availability.py b/openstackclient/tests/functional/network/v2/test_ip_availability.py
index 1cdbd487a..be1df9108 100644
--- a/openstackclient/tests/functional/network/v2/test_ip_availability.py
+++ b/openstackclient/tests/functional/network/v2/test_ip_availability.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional.network.v2 import common
@@ -18,6 +19,9 @@
 class IPAvailabilityTests(common.NetworkTests):
     """Functional tests for IP availability"""
 
+    NAME: ClassVar[str]
+    NETWORK_NAME: ClassVar[str]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/network/v2/test_network_meter_rule.py b/openstackclient/tests/functional/network/v2/test_network_meter_rule.py
index c80643e31..268794298 100644
--- a/openstackclient/tests/functional/network/v2/test_network_meter_rule.py
+++ b/openstackclient/tests/functional/network/v2/test_network_meter_rule.py
@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import unittest
 import uuid
 
@@ -22,8 +23,8 @@
 class TestMeterRule(common.NetworkTests):
     """Functional tests for meter rule"""
 
-    METER_ID: str
-    METER_RULE_ID: str
+    METER_ID: ClassVar[str]
+    METER_NAME: ClassVar[str]
 
     @classmethod
     def setUpClass(cls):
diff --git a/openstackclient/tests/functional/network/v2/test_network_segment.py b/openstackclient/tests/functional/network/v2/test_network_segment.py
index 03f5daf74..df26bcc8d 100644
--- a/openstackclient/tests/functional/network/v2/test_network_segment.py
+++ b/openstackclient/tests/functional/network/v2/test_network_segment.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional.network.v2 import common
@@ -18,6 +19,10 @@
 class NetworkSegmentTests(common.NetworkTests):
     """Functional tests for network segment"""
 
+    NETWORK_NAME: ClassVar[str]
+    NETWORK_ID: ClassVar[str]
+    PHYSICAL_NETWORK_NAME: ClassVar[str]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/network/v2/test_subnet.py b/openstackclient/tests/functional/network/v2/test_subnet.py
index 2ec987e9b..6af7c9454 100644
--- a/openstackclient/tests/functional/network/v2/test_subnet.py
+++ b/openstackclient/tests/functional/network/v2/test_subnet.py
@@ -11,6 +11,7 @@
 #    under the License.
 
 import random
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional.network.v2 import common
@@ -21,19 +22,22 @@ class SubnetTests(common.NetworkTagTests):
 
     base_command = 'subnet'
 
+    NETWORK_NAME: ClassVar[str]
+    NETWORK_ID: ClassVar[str]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
-        if cls.haz_network:
-            cls.NETWORK_NAME = uuid.uuid4().hex
 
-            # Create a network for the all subnet tests
-            cmd_output = cls.openstack(
-                'network create ' + cls.NETWORK_NAME,
-                parse_output=True,
-            )
-            # Get network_id for assertEqual
-            cls.NETWORK_ID = cmd_output["id"]
+        cls.NETWORK_NAME = uuid.uuid4().hex
+
+        # Create a network for the all subnet tests
+        cmd_output = cls.openstack(
+            'network create ' + cls.NETWORK_NAME,
+            parse_output=True,
+        )
+        # Get network_id for assertEqual
+        cls.NETWORK_ID = cmd_output["id"]
 
     @classmethod
     def tearDownClass(cls):
diff --git a/openstackclient/tests/functional/object/v1/common.py b/openstackclient/tests/functional/object/v1/common.py
index 036731da5..f3cc9aea9 100644
--- a/openstackclient/tests/functional/object/v1/common.py
+++ b/openstackclient/tests/functional/object/v1/common.py
@@ -10,12 +10,16 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
+
 from openstackclient.tests.functional import base
 
 
 class ObjectStoreTests(base.TestCase):
     """Functional tests for Object Store commands"""
 
+    haz_object_store: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/volume/v2/common.py b/openstackclient/tests/functional/volume/v2/common.py
index f15d4d961..ed55030d2 100644
--- a/openstackclient/tests/functional/volume/v2/common.py
+++ b/openstackclient/tests/functional/volume/v2/common.py
@@ -10,6 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
+
 import fixtures
 
 from openstackclient.tests.functional.volume import base
@@ -18,6 +20,8 @@
 class BaseVolumeTests(base.BaseVolumeTests):
     """Base class for Volume functional tests."""
 
+    haz_volume_v2: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/volume/v2/test_volume_snapshot.py b/openstackclient/tests/functional/volume/v2/test_volume_snapshot.py
index e5daded1b..a5302033b 100644
--- a/openstackclient/tests/functional/volume/v2/test_volume_snapshot.py
+++ b/openstackclient/tests/functional/volume/v2/test_volume_snapshot.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional.volume.v2 import common
@@ -18,24 +19,27 @@
 class VolumeSnapshotTests(common.BaseVolumeTests):
     """Functional tests for volume snapshot."""
 
-    VOLLY = uuid.uuid4().hex
+    VOLUME_NAME = uuid.uuid4().hex
+    VOLUME_ID: ClassVar[str]
 
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
         # create a volume for all tests to create snapshot
         cmd_output = cls.openstack(
-            'volume create ' + '--size 1 ' + cls.VOLLY,
+            'volume create ' + '--size 1 ' + cls.VOLUME_NAME,
             parse_output=True,
         )
-        cls.wait_for_status('volume', cls.VOLLY, 'available')
+        cls.wait_for_status('volume', cls.VOLUME_NAME, 'available')
         cls.VOLUME_ID = cmd_output['id']
 
     @classmethod
     def tearDownClass(cls):
         try:
-            cls.wait_for_status('volume', cls.VOLLY, 'available')
-            raw_output = cls.openstack('volume delete --force ' + cls.VOLLY)
+            cls.wait_for_status('volume', cls.VOLUME_NAME, 'available')
+            raw_output = cls.openstack(
+                'volume delete --force ' + cls.VOLUME_NAME
+            )
             cls.assertOutput('', raw_output)
         finally:
             super().tearDownClass()
@@ -44,7 +48,10 @@ def test_volume_snapshot_delete(self):
         """Test create, delete multiple"""
         name1 = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'volume snapshot create ' + name1 + ' --volume ' + self.VOLLY,
+            'volume snapshot create '
+            + name1
+            + ' --volume '
+            + self.VOLUME_NAME,
             parse_output=True,
         )
         self.assertEqual(
@@ -54,7 +61,10 @@ def test_volume_snapshot_delete(self):
 
         name2 = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'volume snapshot create ' + name2 + ' --volume ' + self.VOLLY,
+            'volume snapshot create '
+            + name2
+            + ' --volume '
+            + self.VOLUME_NAME,
             parse_output=True,
         )
         self.assertEqual(
@@ -76,7 +86,10 @@ def test_volume_snapshot_list(self):
         """Test create, list filter"""
         name1 = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'volume snapshot create ' + name1 + ' --volume ' + self.VOLLY,
+            'volume snapshot create '
+            + name1
+            + ' --volume '
+            + self.VOLUME_NAME,
             parse_output=True,
         )
         self.addCleanup(self.wait_for_delete, 'volume snapshot', name1)
@@ -97,7 +110,10 @@ def test_volume_snapshot_list(self):
 
         name2 = uuid.uuid4().hex
         cmd_output = self.openstack(
-            'volume snapshot create ' + name2 + ' --volume ' + self.VOLLY,
+            'volume snapshot create '
+            + name2
+            + ' --volume '
+            + self.VOLUME_NAME,
             parse_output=True,
         )
         self.addCleanup(self.wait_for_delete, 'volume snapshot', name2)
@@ -146,7 +162,7 @@ def test_volume_snapshot_list(self):
 
         # Test list --volume
         cmd_output = self.openstack(
-            'volume snapshot list ' + '--volume ' + self.VOLLY,
+            'volume snapshot list ' + '--volume ' + self.VOLUME_NAME,
             parse_output=True,
         )
         names = [x["Name"] for x in cmd_output]
@@ -169,7 +185,7 @@ def test_volume_snapshot_set(self):
         cmd_output = self.openstack(
             'volume snapshot create '
             + '--volume '
-            + self.VOLLY
+            + self.VOLUME_NAME
             + ' --description aaaa '
             + '--property Alpha=a '
             + name,
diff --git a/openstackclient/tests/functional/volume/v3/common.py b/openstackclient/tests/functional/volume/v3/common.py
index cbab39275..038991313 100644
--- a/openstackclient/tests/functional/volume/v3/common.py
+++ b/openstackclient/tests/functional/volume/v3/common.py
@@ -10,6 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
+
 import fixtures
 
 from openstackclient.tests.functional.volume import base
@@ -18,6 +20,8 @@
 class BaseVolumeTests(base.BaseVolumeTests):
     """Base class for Volume functional tests."""
 
+    haz_volume_v3: ClassVar[bool]
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/openstackclient/tests/functional/volume/v3/test_volume_snapshot.py b/openstackclient/tests/functional/volume/v3/test_volume_snapshot.py
index b84bb0368..6921c997d 100644
--- a/openstackclient/tests/functional/volume/v3/test_volume_snapshot.py
+++ b/openstackclient/tests/functional/volume/v3/test_volume_snapshot.py
@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from typing import ClassVar
 import uuid
 
 from openstackclient.tests.functional.volume.v3 import common
@@ -18,24 +19,27 @@
 class VolumeSnapshotTests(common.BaseVolumeTests):
     """Functional tests for volume snapshot."""
 
-    VOLLY = uuid.uuid4().hex
+    VOLUME_NAME = uuid.uuid4().hex
+    VOLUME_ID: ClassVar[str]
 
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
         # create a test volume used by all snapshot tests
         cmd_output = cls.openstack(
-            'volume create ' + '--size 1 ' + cls.VOLLY,
+            'volume create ' + '--size 1 ' + cls.VOLUME_NAME,
             parse_output=True,
         )
-        cls.wait_for_status('volume', cls.VOLLY, 'available')
+        cls.wait_for_status('volume', cls.VOLUME_NAME, 'available')
         cls.VOLUME_ID = cmd_output['id']
 
     @classmethod
     def tearDownClass(cls):
         try:
-            cls.wait_for_status('volume', cls.VOLLY, 'available')
-            raw_output = cls.openstack('volume delete --force ' + cls.VOLLY)
+            cls.wait_for_status('volume', cls.VOLUME_NAME, 'available')
+            raw_output = cls.openstack(
+                'volume delete --force ' + cls.VOLUME_NAME
+            )
             cls.assertOutput('', raw_output)
         finally:
             super().tearDownClass()
@@ -47,7 +51,7 @@ def test_volume_snapshot(self):
         cmd_output = self.openstack(
             'volume snapshot create '
             + '--volume '
-            + self.VOLLY
+            + self.VOLUME_NAME
             + ' --description aaaa '
             + '--property Alpha=a '
             + name,
@@ -83,7 +87,7 @@ def test_volume_snapshot(self):
 
         # list volume snapshot --volume
         cmd_output = self.openstack(
-            'volume snapshot list ' + '--volume ' + self.VOLLY,
+            'volume snapshot list ' + '--volume ' + self.VOLUME_NAME,
             parse_output=True,
         )
         names = [x["Name"] for x in cmd_output]
diff --git a/tox.ini b/tox.ini
index 6ce9e96c6..1b7c7cc48 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ setenv =
   OS_STDERR_CAPTURE=1
   OS_TEST_TIMEOUT=60
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2026.1}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 commands =
@@ -65,7 +65,7 @@ commands =
 description =
   Run specified command in a virtual environment with all dependencies installed.
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2026.1}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
 commands =
@@ -95,7 +95,7 @@ commands =
 description =
   Build documentation in HTML format.
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2026.1}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d doc/build/doctrees -b html doc/source doc/build/html
@@ -107,7 +107,7 @@ commands =
 description =
   Build release note documentation in HTML format.
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2026.1}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html