diff --git a/pagure/api/project.py b/pagure/api/project.py
index 2a9e918..d4ac7ee 100644
--- a/pagure/api/project.py
+++ b/pagure/api/project.py
@@ -115,6 +115,7 @@ def api_project_watchers(repo, username=None, namespace=None):
         implicit_watch_users = \
             implicit_watch_users | set(
                 [user.username for user in repo.access_users[access_type]])
+
     watching_users_to_watch_level = {}
     for implicit_watch_user in implicit_watch_users:
         user_watch_level = pagure.lib.get_watch_level_on_repo(
@@ -682,10 +683,25 @@ def api_project(repo, username=None, namespace=None):
     repo = get_authorized_api_project(
         SESSION, repo, user=username, namespace=namespace)
 
+    expand_group = str(
+            flask.request.values.get('expand_group', None)
+        ).lower() in ['1', 't', 'True']
+
     if repo is None:
         raise pagure.exceptions.APIError(404, error_code=APIERROR.ENOPROJECT)
 
-    jsonout = flask.jsonify(repo.to_json(api=True, public=True))
+    output = repo.to_json(api=True, public=True)
+
+    if expand_group:
+        group_details = {}
+        for grp in repo.projects_groups:
+            group = pagure.lib.search_groups(
+                SESSION, group_name=grp.group.group_name)
+            group_details[grp.group.group_name] = [
+                user.username for user in grp.group.users]
+        output['group_details'] = group_details
+
+    jsonout = flask.jsonify(output)
     return jsonout
 
 
diff --git a/tests/test_pagure_flask_api_project.py b/tests/test_pagure_flask_api_project.py
index e392c1e..0876e21 100644
--- a/tests/test_pagure_flask_api_project.py
+++ b/tests/test_pagure_flask_api_project.py
@@ -852,6 +852,161 @@ class PagureFlaskApiProjecttests(tests.Modeltests):
         }
         self.assertDictEqual(data, expected_data)
 
+    def test_api_project_group(self):
+        """ Test the api_project method of the flask api. """
+        tests.create_projects(self.session)
+        repo = pagure.get_authorized_project(self.session, 'test')
+
+        # Adding a tag
+        output = pagure.lib.update_tags(
+            self.session, repo, 'infra', 'pingou',
+            ticketfolder=None)
+        self.assertEqual(output, ['Issue tagged with: infra'])
+
+        # Check after adding
+        repo = pagure.get_authorized_project(self.session, 'test')
+        self.assertEqual(len(repo.tags), 1)
+        self.assertEqual(repo.tags_text, ['infra'])
+
+        # Add a group to the project
+        msg = pagure.lib.add_group(
+            self.session,
+            group_name='some_group',
+            display_name='Some Group',
+            description=None,
+            group_type='bar',
+            user='foo',
+            is_admin=False,
+            blacklist=[],
+        )
+        self.session.commit()
+
+        project = pagure.get_authorized_project(self.session, 'test')
+        group = pagure.lib.search_groups(
+            self.session, group_name='some_group')
+
+        pagure.lib.add_group_to_project(
+            self.session,
+            project,
+            new_group='some_group',
+            user='pingou',
+            access='commit',
+            create=False,
+            is_admin=True
+        )
+        self.session.commit()
+
+        # Check the API
+
+        # Existing project
+        output = self.app.get('/api/0/test?expand_group=1')
+        self.assertEqual(output.status_code, 200)
+        data = json.loads(output.data)
+        data['date_created'] = "1436527638"
+        data['date_modified'] = "1436527638"
+        expected_data ={
+            "access_groups": {
+                "admin": [],
+                "commit": ["some_group"],
+                "ticket": []
+            },
+            "access_users": {
+                "admin": [],
+                "commit": [],
+                "owner": ["pingou"],
+                "ticket": []},
+            "close_status": [
+                "Invalid",
+                "Insufficient data",
+                "Fixed",
+                "Duplicate"
+            ],
+            "custom_keys": [],
+            "date_created": "1436527638",
+            "date_modified": "1436527638",
+            "description": "test project #1",
+            "fullname": "test",
+            "group_details": {
+              "some_group": [
+                "foo"
+              ]
+            },
+            "id": 1,
+            "milestones": {},
+            "name": "test",
+            "namespace": None,
+            "parent": None,
+            "priorities": {},
+            "tags": ["infra"],
+            "user": {
+                "fullname": "PY C",
+                "name": "pingou"
+            }
+        }
+        self.assertDictEqual(data, expected_data)
+
+    def test_api_project_group_but_no_group(self):
+        """ Test the api_project method of the flask api when asking for
+        group details while there are none associated.
+        """
+        tests.create_projects(self.session)
+        repo = pagure.get_authorized_project(self.session, 'test')
+
+        # Adding a tag
+        output = pagure.lib.update_tags(
+            self.session, repo, 'infra', 'pingou',
+            ticketfolder=None)
+        self.assertEqual(output, ['Issue tagged with: infra'])
+
+        # Check after adding
+        repo = pagure.get_authorized_project(self.session, 'test')
+        self.assertEqual(len(repo.tags), 1)
+        self.assertEqual(repo.tags_text, ['infra'])
+
+        # Check the API
+
+        # Existing project
+        output = self.app.get('/api/0/test?expand_group=0')
+        self.assertEqual(output.status_code, 200)
+        data = json.loads(output.data)
+        data['date_created'] = "1436527638"
+        data['date_modified'] = "1436527638"
+        expected_data ={
+            "access_groups": {
+                "admin": [],
+                "commit": [],
+                "ticket": []
+            },
+            "access_users": {
+                "admin": [],
+                "commit": [],
+                "owner": ["pingou"],
+                "ticket": []},
+            "close_status": [
+                "Invalid",
+                "Insufficient data",
+                "Fixed",
+                "Duplicate"
+            ],
+            "custom_keys": [],
+            "date_created": "1436527638",
+            "date_modified": "1436527638",
+            "description": "test project #1",
+            "fullname": "test",
+            "id": 1,
+            "milestones": {},
+            "name": "test",
+            "namespace": None,
+            "parent": None,
+            "priorities": {},
+            "tags": ["infra"],
+            "user": {
+                "fullname": "PY C",
+                "name": "pingou"
+            }
+        }
+        self.assertDictEqual(data, expected_data)
+
     def test_api_projects_pagination(self):
         """ Test the api_projects method of the flask api with pagination. """
         tests.create_projects(self.session)