diff --git a/doc/source/plugin.rst b/doc/source/plugin.rst
index 77ef9ed..2afb1e5 100644
--- a/doc/source/plugin.rst
+++ b/doc/source/plugin.rst
@@ -29,6 +29,8 @@
 * tempest.config
 * tempest.test_discover.plugins
 * tempest.common.credentials_factory
+* tempest.clients
+* tempest.test
 
 If there is an interface from tempest that you need to rely on in your plugin
 which is not listed above, it likely needs to be migrated to tempest.lib. In
diff --git a/releasenotes/notes/add_proxy_url_get_credentials-aef66b085450513f.yaml b/releasenotes/notes/add_proxy_url_get_credentials-aef66b085450513f.yaml
new file mode 100644
index 0000000..94ab462
--- /dev/null
+++ b/releasenotes/notes/add_proxy_url_get_credentials-aef66b085450513f.yaml
@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Add the proxy_url optional parameter to the get_credentials method in
+    tempest/lib/auth.py so that that helper can be used when going through
+    and HTTP proxy.
diff --git a/releasenotes/notes/test-clients-stable-for-plugin-90b1e7dc83f28ccd.yaml b/releasenotes/notes/test-clients-stable-for-plugin-90b1e7dc83f28ccd.yaml
new file mode 100644
index 0000000..e27ee33
--- /dev/null
+++ b/releasenotes/notes/test-clients-stable-for-plugin-90b1e7dc83f28ccd.yaml
@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    Two extra modules are now marked as stable for plugins, test.py and clients.py.
+    The former includes the test base class with its automatic credentials
+    provisioning and test resource managing fixtures.
+    The latter is built on top of ServiceClients and it adds aliases and a few custom
+    configurations to it.
diff --git a/tempest/api/compute/floating_ips/base.py b/tempest/api/compute/floating_ips/base.py
index 142eaec..262a3c1 100644
--- a/tempest/api/compute/floating_ips/base.py
+++ b/tempest/api/compute/floating_ips/base.py
@@ -14,6 +14,10 @@
 #    under the License.
 
 from tempest.api.compute import base
+from tempest.common import utils
+from tempest import config
+
+CONF = config.CONF
 
 
 class BaseFloatingIPsTest(base.BaseV2ComputeTest):
@@ -24,3 +28,17 @@
         cls.set_network_resources(network=True, subnet=True,
                                   router=True, dhcp=True)
         super(BaseFloatingIPsTest, cls).setup_credentials()
+
+    @classmethod
+    def skip_checks(cls):
+        super(BaseFloatingIPsTest, cls).skip_checks()
+        if not utils.get_service_list()['network']:
+            raise cls.skipException("network service not enabled.")
+        if not CONF.network_feature_enabled.floating_ips:
+            raise cls.skipException("Floating ips are not available")
+
+    @classmethod
+    def setup_clients(cls):
+        super(BaseFloatingIPsTest, cls).setup_clients()
+        cls.client = cls.floating_ips_client
+        cls.pools_client = cls.floating_ip_pools_client
diff --git a/tempest/api/compute/floating_ips/test_floating_ips_actions.py b/tempest/api/compute/floating_ips/test_floating_ips_actions.py
index 8938570..2adc482 100644
--- a/tempest/api/compute/floating_ips/test_floating_ips_actions.py
+++ b/tempest/api/compute/floating_ips/test_floating_ips_actions.py
@@ -16,7 +16,6 @@
 import testtools
 
 from tempest.api.compute.floating_ips import base
-from tempest.common import utils
 from tempest import config
 from tempest.lib.common.utils import test_utils
 from tempest.lib import decorators
@@ -27,32 +26,7 @@
 
 class FloatingIPsTestJSON(base.BaseFloatingIPsTest):
 
-    @classmethod
-    def skip_checks(cls):
-        super(FloatingIPsTestJSON, cls).skip_checks()
-        if not utils.get_service_list()['network']:
-            raise cls.skipException("network service not enabled.")
-        if not CONF.network_feature_enabled.floating_ips:
-            raise cls.skipException("Floating ips are not available")
-
-    @classmethod
-    def setup_clients(cls):
-        super(FloatingIPsTestJSON, cls).setup_clients()
-        cls.client = cls.floating_ips_client
-
-    @classmethod
-    def resource_setup(cls):
-        super(FloatingIPsTestJSON, cls).resource_setup()
-
-        # Server creation
-        server = cls.create_test_server(wait_until='ACTIVE')
-        cls.server_id = server['id']
-        # Floating IP creation
-        body = cls.client.create_floating_ip(
-            pool=CONF.network.floating_network_name)['floating_ip']
-        cls.addClassResourceCleanup(cls.client.delete_floating_ip, body['id'])
-        cls.floating_ip_id = body['id']
-        cls.floating_ip = body['ip']
+    max_microversion = '2.35'
 
     @decorators.idempotent_id('f7bfb946-297e-41b8-9e8c-aba8e9bb5194')
     def test_allocate_floating_ip(self):
@@ -83,6 +57,25 @@
         # Check it was really deleted.
         self.client.wait_for_resource_deletion(floating_ip_body['id'])
 
+
+class FloatingIPsAssociationTestJSON(base.BaseFloatingIPsTest):
+
+    max_microversion = '2.43'
+
+    @classmethod
+    def resource_setup(cls):
+        super(FloatingIPsAssociationTestJSON, cls).resource_setup()
+
+        # Server creation
+        cls.server = cls.create_test_server(wait_until='ACTIVE')
+        cls.server_id = cls.server['id']
+        # Floating IP creation
+        body = cls.client.create_floating_ip(
+            pool=CONF.network.floating_network_name)['floating_ip']
+        cls.addClassResourceCleanup(cls.client.delete_floating_ip, body['id'])
+        cls.floating_ip_id = body['id']
+        cls.floating_ip = body['ip']
+
     @decorators.idempotent_id('307efa27-dc6f-48a0-8cd2-162ce3ef0b52')
     @testtools.skipUnless(CONF.network.public_network_id,
                           'The public_network_id option must be specified.')
diff --git a/tempest/api/compute/floating_ips/test_floating_ips_actions_negative.py b/tempest/api/compute/floating_ips/test_floating_ips_actions_negative.py
index c3d7816..9257458 100644
--- a/tempest/api/compute/floating_ips/test_floating_ips_actions_negative.py
+++ b/tempest/api/compute/floating_ips/test_floating_ips_actions_negative.py
@@ -16,7 +16,6 @@
 import testtools
 
 from tempest.api.compute.floating_ips import base
-from tempest.common import utils
 from tempest import config
 from tempest.lib.common.utils import data_utils
 from tempest.lib import decorators
@@ -27,26 +26,12 @@
 
 class FloatingIPsNegativeTestJSON(base.BaseFloatingIPsTest):
 
-    @classmethod
-    def skip_checks(cls):
-        super(FloatingIPsNegativeTestJSON, cls).skip_checks()
-        if not utils.get_service_list()['network']:
-            raise cls.skipException("network service not enabled.")
-        if not CONF.network_feature_enabled.floating_ips:
-            raise cls.skipException("Floating ips are not available")
-
-    @classmethod
-    def setup_clients(cls):
-        super(FloatingIPsNegativeTestJSON, cls).setup_clients()
-        cls.client = cls.floating_ips_client
+    max_microversion = '2.35'
 
     @classmethod
     def resource_setup(cls):
         super(FloatingIPsNegativeTestJSON, cls).resource_setup()
 
-        # Server creation
-        server = cls.create_test_server(wait_until='ACTIVE')
-        cls.server_id = server['id']
         # Generating a nonexistent floatingIP id
         body = cls.client.list_floating_ips()['floating_ips']
         floating_ip_ids = [floating_ip['id'] for floating_ip in body]
@@ -77,6 +62,17 @@
         self.assertRaises(lib_exc.NotFound, self.client.delete_floating_ip,
                           self.non_exist_id)
 
+
+class FloatingIPsAssociationNegativeTestJSON(base.BaseFloatingIPsTest):
+
+    max_microversion = '2.43'
+
+    @classmethod
+    def resource_setup(cls):
+        super(FloatingIPsAssociationNegativeTestJSON, cls).resource_setup()
+        cls.server = cls.create_test_server(wait_until='ACTIVE')
+        cls.server_id = cls.server['id']
+
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('595fa616-1a71-4670-9614-46564ac49a4c')
     def test_associate_nonexistent_floating_ip(self):
diff --git a/tempest/api/compute/floating_ips/test_list_floating_ips.py b/tempest/api/compute/floating_ips/test_list_floating_ips.py
index 516c544..944f798 100644
--- a/tempest/api/compute/floating_ips/test_list_floating_ips.py
+++ b/tempest/api/compute/floating_ips/test_list_floating_ips.py
@@ -13,29 +13,16 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from tempest.api.compute import base
-from tempest.common import utils
+from tempest.api.compute.floating_ips import base
 from tempest import config
 from tempest.lib import decorators
 
 CONF = config.CONF
 
 
-class FloatingIPDetailsTestJSON(base.BaseV2ComputeTest):
+class FloatingIPDetailsTestJSON(base.BaseFloatingIPsTest):
 
-    @classmethod
-    def skip_checks(cls):
-        super(FloatingIPDetailsTestJSON, cls).skip_checks()
-        if not utils.get_service_list()['network']:
-            raise cls.skipException("network service not enabled.")
-        if not CONF.network_feature_enabled.floating_ips:
-            raise cls.skipException("Floating ips are not available")
-
-    @classmethod
-    def setup_clients(cls):
-        super(FloatingIPDetailsTestJSON, cls).setup_clients()
-        cls.client = cls.floating_ips_client
-        cls.pools_client = cls.floating_ip_pools_client
+    max_microversion = '2.35'
 
     @classmethod
     def resource_setup(cls):
diff --git a/tempest/api/compute/floating_ips/test_list_floating_ips_negative.py b/tempest/api/compute/floating_ips/test_list_floating_ips_negative.py
index 0ade872..d69248c 100644
--- a/tempest/api/compute/floating_ips/test_list_floating_ips_negative.py
+++ b/tempest/api/compute/floating_ips/test_list_floating_ips_negative.py
@@ -13,8 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from tempest.api.compute import base
-from tempest.common import utils
+from tempest.api.compute.floating_ips import base
 from tempest import config
 from tempest.lib.common.utils import data_utils
 from tempest.lib import decorators
@@ -23,20 +22,9 @@
 CONF = config.CONF
 
 
-class FloatingIPDetailsNegativeTestJSON(base.BaseV2ComputeTest):
+class FloatingIPDetailsNegativeTestJSON(base.BaseFloatingIPsTest):
 
-    @classmethod
-    def skip_checks(cls):
-        super(FloatingIPDetailsNegativeTestJSON, cls).skip_checks()
-        if not utils.get_service_list()['network']:
-            raise cls.skipException("network service not enabled.")
-        if not CONF.network_feature_enabled.floating_ips:
-            raise cls.skipException("Floating ips are not available")
-
-    @classmethod
-    def setup_clients(cls):
-        super(FloatingIPDetailsNegativeTestJSON, cls).setup_clients()
-        cls.client = cls.floating_ips_client
+    max_microversion = '2.35'
 
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('7ab18834-4a4b-4f28-a2c5-440579866695')
diff --git a/tempest/lib/auth.py b/tempest/lib/auth.py
index a850fe1..2dd9d00 100644
--- a/tempest/lib/auth.py
+++ b/tempest/lib/auth.py
@@ -600,7 +600,8 @@
 
 def get_credentials(auth_url, fill_in=True, identity_version='v2',
                     disable_ssl_certificate_validation=None, ca_certs=None,
-                    trace_requests=None, http_timeout=None, **kwargs):
+                    trace_requests=None, http_timeout=None, proxy_url=None,
+                    **kwargs):
     """Builds a credentials object based on the configured auth_version
 
     :param auth_url (string): Full URI of the OpenStack Identity API(Keystone)
@@ -618,6 +619,7 @@
     :param trace_requests: trace in log API requests to the auth system
     :param http_timeout: timeout in seconds to wait for the http request to
            return
+    :param proxy_url: URL of HTTP(s) proxy used when fill_in is True
     :param kwargs (dict): Dict of credential key/value pairs
 
     Examples:
@@ -642,7 +644,7 @@
         auth_provider = auth_provider_class(
             creds, auth_url, disable_ssl_certificate_validation=dscv,
             ca_certs=ca_certs, trace_requests=trace_requests,
-            http_timeout=http_timeout)
+            http_timeout=http_timeout, proxy_url=proxy_url)
         creds = auth_provider.fill_credentials()
     return creds