diff --git a/subiquity/common/apidef.py b/subiquity/common/apidef.py
index e75da3c4..f0f0d0ab 100644
--- a/subiquity/common/apidef.py
+++ b/subiquity/common/apidef.py
@@ -28,6 +28,7 @@ from subiquity.common.types import (
     ADConnectionInfo,
     AdAdminNameValidation,
     AdDomainNameValidation,
+    AdJoinResult,
     AdPasswordValidation,
     AddPartitionV2,
     AnyStep,
@@ -434,6 +435,9 @@ class API:
         class check_password:
             def POST(password: Payload[str]) -> AdPasswordValidation: ...
 
+        class join_result:
+            def GET(wait: bool = True) -> AdJoinResult: ...
+
 
 class LinkAction(enum.Enum):
     NEW = enum.auto()
diff --git a/subiquity/common/types.py b/subiquity/common/types.py
index 732408b1..e33cfc7f 100644
--- a/subiquity/common/types.py
+++ b/subiquity/common/types.py
@@ -801,3 +801,9 @@ class AdDomainNameValidation(enum.Enum):
 class AdPasswordValidation(enum.Enum):
     OK = 'OK'
     EMPTY = 'Empty'
+
+
+class AdJoinResult(enum.Enum):
+    OK = 'OK'
+    JOIN_ERROR = 'Failed to join'
+    UNKNOWN = "Didn't attempt to join yet"
diff --git a/subiquity/server/ad_joiner.py b/subiquity/server/ad_joiner.py
new file mode 100644
index 00000000..2801c0f2
--- /dev/null
+++ b/subiquity/server/ad_joiner.py
@@ -0,0 +1,41 @@
+# Copyright 2023 Canonical, Ltd.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import asyncio
+from subiquity.common.types import (
+    ADConnectionInfo,
+    AdJoinResult,
+)
+
+
+class AdJoiner():
+    def __init__(self):
+        self._result = AdJoinResult.UNKNOWN
+        self.join_task = None
+
+    async def join_domain(self, info: ADConnectionInfo) -> AdJoinResult:
+        self.join_task = asyncio.create_task(self.async_join(info))
+        self._result = await self.join_task
+        return self._result
+
+    async def async_join(self, info: ADConnectionInfo) -> AdJoinResult:
+        # TODO: Join.
+        return await asyncio.sleep(3, result=AdJoinResult.JOIN_ERROR)
+
+    async def join_result(self):
+        if self.join_task is None:
+            return AdJoinResult.UNKNOWN
+
+        return await self.join_task
diff --git a/subiquity/server/controllers/ad.py b/subiquity/server/controllers/ad.py
index 346f6210..89f2e8d6 100644
--- a/subiquity/server/controllers/ad.py
+++ b/subiquity/server/controllers/ad.py
@@ -25,8 +25,10 @@ from subiquity.common.types import (
     ADConnectionInfo,
     AdAdminNameValidation,
     AdDomainNameValidation,
+    AdJoinResult,
     AdPasswordValidation
 )
+from subiquity.server.ad_joiner import AdJoiner
 from subiquity.server.controller import SubiquityController
 
 log = logging.getLogger('subiquity.server.controllers.ad')
@@ -95,6 +97,8 @@ class ADController(SubiquityController):
 
     def __init__(self, app):
         super().__init__(app)
+        self.ad_joiner = None
+        self.join_result = AdJoinResult.UNKNOWN
         if self.app.opts.dry_run:
             self.ping_strgy = StubDcPingStrategy()
         else:
@@ -141,6 +145,23 @@ class ADController(SubiquityController):
             to configure AD are present in the live system."""
         return self.ping_strgy.has_support()
 
+    async def join_result_GET(self, wait: bool = True) -> AdJoinResult:
+        # Enables testing the API without the need for the install controller
+        if self.app.opts.dry_run and self.ad_joiner is None:
+            await self.join_domain()
+
+        if wait and self.ad_joiner:
+            self.join_result = await self.ad_joiner.join_result()
+
+        return self.join_result
+
+    async def join_domain(self) -> None:
+        """To be called from the install controller if joining was requested"""
+        if self.ad_joiner is None:
+            self.ad_joiner = AdJoiner()
+
+        await self.ad_joiner.join_domain(self.model.conn_info)
+
 
 # Helper out-of-class functions grouped.
 class AdValidators:
diff --git a/subiquity/server/controllers/install.py b/subiquity/server/controllers/install.py
index 8f99322f..55fbabb1 100644
--- a/subiquity/server/controllers/install.py
+++ b/subiquity/server/controllers/install.py
@@ -406,6 +406,8 @@ class InstallController(SubiquityController):
             policy = self.model.updates.updates
             await self.run_unattended_upgrades(context=context, policy=policy)
         await self.restore_apt_config(context=context)
+        if self.model.ad.do_join:
+            await self.app.controllers.Ad.join_domain()
 
     @with_context(description="configuring cloud-init")
     async def configure_cloud_init(self, context):
diff --git a/subiquity/tests/api/test_api.py b/subiquity/tests/api/test_api.py
index 77c2d4a0..b501e7a1 100644
--- a/subiquity/tests/api/test_api.py
+++ b/subiquity/tests/api/test_api.py
@@ -1696,3 +1696,6 @@ class TestActiveDirectory(TestAPI):
             result = await instance.post(endpoint + '/check_admin_name',
                                          data='$Ubuntu')
             self.assertEqual('OK', result)
+            # Attempts to join with the info supplied above.
+            join_result = await instance.get(endpoint + '/join_result')
+            self.assertEqual('JOIN_ERROR', join_result)