♻️(frontend) derive is_administrable from participant metadata

The is_administrable flag was previously read from the room API
response through the room serializer, giving the frontend static
information about the user's rights.

Refactor the frontend so it derives this flag from the participant
role carried in the participant metadata instead.

Two benefits:

* The flag now updates live along with the participant
  attributes/metadata, so role changes are reflected immediately.
* It removes the duplication between the API response and the
  metadata, which both used to determine the user's capabilities.

src/backend/core/api/permissions.py

@@ -6,6 +6,11 @@ from django.http import Http404
 from rest_framework import permissions
 
 from ..models import RoleChoices
+from ..services.participants_management import (
+    ParticipantNotFoundException,
+    ParticipantsManagement,
+    ParticipantsManagementException,
+)
 
 ACTION_FOR_METHOD_TO_PERMISSION = {
     "versions_detail": {"DELETE": "versions_destroy", "GET": "versions_retrieve"}
@@ -166,3 +171,30 @@ class CanMuteParticipant(permissions.BasePermission):
 
         # LiveKit token scoped to this room
         return request.auth.video.room == str(obj.id)
+
+
+class IsPresentInMeeting(permissions.BasePermission):
+    """Check that the requesting user is currently connected to the meeting.
+
+    The requester must be session-authenticated (their DB identity is needed
+    to check privileges); presence is verified against LiveKit using their
+    `sub` as participant identity. Fails closed on LiveKit errors.
+    """
+
+    message = "You must be connected to the meeting to perform this action."
+
+    def has_object_permission(self, request, view, obj):
+        """Verify the requester's identity is a participant of the room."""
+        user = request.user
+
+        if not user or not user.is_authenticated:
+            return False
+
+        try:
+            return ParticipantsManagement().check_if_in_meeting(
+                room_name=str(obj.pk), identity=str(user.sub)
+            )
+        except ParticipantNotFoundException:
+            return False
+        except ParticipantsManagementException:
+            return False

src/backend/core/api/serializers.py

@@ -183,13 +183,12 @@ class RoomSerializer(serializers.ModelSerializer):
                 user=request.user,
                 username=username,
                 configuration=output["configuration"],
-                is_admin_or_owner=is_admin_or_owner,
+                role=role,
+                is_authenticated=request.user.is_authenticated,
             )
         else:
             del output["pin_code"]
 
-        output["is_administrable"] = is_admin_or_owner
-
         return output
 
 
@@ -312,6 +311,15 @@ class MuteParticipantSerializer(BaseParticipantsManagementSerializer):
     )
 
 
+class ParticipantRoleSerializer(BaseParticipantsManagementSerializer):
+    """Validate an in-meeting role change (promotion/demotion) request."""
+
+    role = serializers.ChoiceField(
+        choices=[models.RoleChoices.MEMBER, models.RoleChoices.ADMIN],
+        help_text="Target role. Ownership cannot be granted this way.",
+    )
+
+
 TrackSource = Literal["camera", "microphone", "screen_share", "screen_share_audio"]
 
 

src/backend/core/api/viewsets.py

@@ -88,6 +88,10 @@ from core.services.room_management import (
     RoomManagementException,
     RoomNotFoundException,
 )
+from core.services.room_roles import (
+    RoomRoleError,
+    RoomRoleService,
+)
 from core.services.subtitle import SubtitleException, SubtitleService
 from core.tasks.file import process_file_deletion
 
@@ -639,6 +643,53 @@ class RoomViewSet(
             status=drf_status.HTTP_200_OK,
         )
 
+    @decorators.action(
+        detail=True,
+        methods=["post"],
+        url_path="update-participant-role",
+        permission_classes=[
+            permissions.HasPrivilegesOnRoom,
+            permissions.IsPresentInMeeting,
+        ],
+    )
+    def update_participant_role(self, request, pk=None):  # pylint: disable=unused-argument
+        """Promote or demote a participant currently connected to the meeting.
+
+        Requires the requester to be session-authenticated, have privileges
+        (admin/owner) on the room, and be connected to the meeting.
+
+        If the target participant has a user account, the role is persisted
+        (`ResourceAccess`) then mirrored to their LiveKit attributes.
+
+        If the participant is anonymous, the promotion will fail.
+        """
+
+        room = self.get_object()
+
+        serializer = serializers.ParticipantRoleSerializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+
+        participant_identity = serializer.validated_data["participant_identity"]
+        role = serializer.validated_data["role"]
+
+        if str(request.user.sub) == str(participant_identity):
+            return drf_response.Response(
+                {"error": "You cannot change your own role."},
+                status=drf_status.HTTP_403_FORBIDDEN,
+            )
+
+        try:
+            result = RoomRoleService().set_participant_role(
+                room=room,
+                participant_identity=participant_identity,
+                role=role,
+                actor=request.user,
+            )
+        except RoomRoleError as e:
+            return drf_response.Response({"error": str(e)}, status=e.status_code)
+
+        return drf_response.Response(result, status=drf_status.HTTP_200_OK)
+
     @decorators.action(
         detail=True,
         methods=["post"],

src/backend/core/services/lobby.py

@@ -162,7 +162,6 @@ class LobbyService:
                 username=username,
                 color=participant.color,
                 configuration=room.configuration,
-                is_admin_or_owner=False,
                 participant_id=participant_id,
             )
             return participant, livekit_config
@@ -183,7 +182,6 @@ class LobbyService:
                 username=username,
                 color=participant.color,
                 configuration=room.configuration,
-                is_admin_or_owner=False,
                 participant_id=participant_id,
             )
 

src/backend/core/services/room_roles.py

@@ -0,0 +1,178 @@
+"""Room role management service.
+
+Single entry point for changing a user's role on a room, used by:
+- the in-meeting endpoint (promote/demote a connected participant)
+- (more to come soon)
+
+`ResourceAccess` is the source of truth. The LiveKit `room_role`
+participant attribute is only a projection of it, synced best-effort.
+"""
+
+from logging import getLogger
+from uuid import UUID
+
+from core import models
+from core.services.participants_management import (
+    ParticipantNotFoundException,
+    ParticipantsManagement,
+    ParticipantsManagementException,
+)
+
+logger = getLogger(__name__)
+
+
+class RoomRoleError(Exception):
+    """Base exception for room role management errors."""
+
+    status_code = 400
+
+
+class SelfActionError(RoomRoleError):
+    """Raised when a user tries to change their own role."""
+
+    status_code = 403
+
+
+class OwnerRoleError(RoomRoleError):
+    """Raised when trying to demote an owner or grant ownership."""
+
+    status_code = 403
+
+
+class ParticipantNotInMeetingError(RoomRoleError):
+    """Raised when the target participant is not connected to the meeting."""
+
+    status_code = 404
+
+
+class UserNotFoundError(RoomRoleError):
+    """Raised when the target participant has no user account in database."""
+
+    status_code = 404
+
+
+ASSIGNABLE_ROLES = (models.RoleChoices.MEMBER, models.RoleChoices.ADMIN)
+
+
+class RoomRoleService:
+    """Manage promotion and demotion of room co-hosts."""
+
+    def set_role(
+        self, room: models.Room, user: models.User, role: str, actor: models.User
+    ):
+        """Persist `role` for `user` on `room`, idempotently and atomically.
+
+        Returns the up-to-date `ResourceAccess`. Never grants or removes
+        ownership: granting OWNER is refused, and an existing OWNER access
+        is never modified.
+        """
+
+        if role not in ASSIGNABLE_ROLES:
+            raise OwnerRoleError("Ownership cannot be granted through this action.")
+
+        if actor is not None and user == actor:
+            raise SelfActionError("You cannot change your own role.")
+
+        access, created = models.ResourceAccess.objects.get_or_create(
+            resource=room,
+            user=user,
+            defaults={"role": role},
+        )
+
+        if created:
+            return access
+
+        if access.role == models.RoleChoices.OWNER:
+            raise OwnerRoleError("Room owners cannot be demoted.")
+
+        if access.role != role:
+            access.role = role
+            access.save(update_fields=["role", "updated_at"])
+
+        return access
+
+    def set_participant_role(
+        self,
+        room: models.Room,
+        participant_identity: UUID,
+        role: str,
+        actor: models.User,
+    ):
+        """Change the role of a participant currently connected to the meeting.
+
+        - The participant must be connected (checked against LiveKit).
+        - The participant must map to a user account.
+        - The role is persisted in DB then mirrored to LiveKit.
+
+        Returns a dict: {"role", "livekit_synced"}.
+        """
+
+        room_name = str(room.pk)
+        participants_management = ParticipantsManagement()
+
+        try:
+            is_in_meeting = participants_management.check_if_in_meeting(
+                room_name=room_name, identity=str(participant_identity)
+            )
+        except ParticipantNotFoundException as e:
+            raise ParticipantNotInMeetingError(
+                "Participant is not connected to this meeting."
+            ) from e
+
+        if not is_in_meeting:
+            raise ParticipantNotInMeetingError(
+                "Participant is not connected to this meeting."
+            )
+
+        user = models.User.objects.filter(sub=participant_identity).first()
+
+        if user is None:
+            raise UserNotFoundError(
+                "This participant has no user account and cannot be assigned a role."
+            )
+
+        # Source of truth first: even if the LiveKit sync below fails,
+        # the role is real and any fresh token will carry it.
+        self.set_role(room=room, user=user, role=role, actor=actor)
+
+        livekit_synced = self._sync_livekit_role(
+            room_name=room_name,
+            participant_identity=str(participant_identity),
+            role=str(role),
+        )
+
+        return {
+            "role": role,
+            "livekit_synced": livekit_synced,
+        }
+
+    @staticmethod
+    def _sync_livekit_role(room_name: str, participant_identity: str, role: str):
+        """Mirror the role to the participant's LiveKit attributes.
+
+        Best-effort: returns False on failure instead of raising, so callers
+        can report a partial success. Re-running the action re-syncs.
+        """
+        try:
+            ParticipantsManagement().update(
+                room_name=room_name,
+                identity=participant_identity,
+                attributes={"room_role": role},
+            )
+        except ParticipantNotFoundException:
+            # The participant left between the presence check and the update:
+            # harmless, the DB state (if any) remains authoritative.
+            logger.info(
+                "Participant %s left room %s before role sync",
+                participant_identity,
+                room_name,
+            )
+            return False
+        except ParticipantsManagementException:
+            logger.exception(
+                "Could not sync role to LiveKit for participant %s in room %s",
+                participant_identity,
+                room_name,
+            )
+            return False
+        return True

src/backend/core/tests/rooms/test_api_rooms_participants_management.py

@@ -80,7 +80,7 @@ def test_mute_participant_with_livekit_token_for_this_room(mock_livekit_client):
     room = RoomFactory()
 
     user = AnonymousUser()
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -106,7 +106,7 @@ def test_mute_participant_with_livekit_token_for_another_room_forbidden(
     other_room = RoomFactory()
 
     user = AnonymousUser()
-    token = utils.generate_token(str(other_room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(other_room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": target_room.id})
     response = client.post(
@@ -146,7 +146,7 @@ def test_mute_participant_everyone_can_mute_disabled_blocks_non_admin(
     room = RoomFactory(configuration={"everyone_can_mute": False})
 
     user = AnonymousUser()
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -293,7 +293,7 @@ def test_mute_participant_admin_with_token_for_this_room(mock_livekit_client):
     )
     # Token identity matches the admin user so LiveKitTokenAuthentication
     # resolves request.user back to the admin.
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=True)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -323,7 +323,7 @@ def test_mute_participant_admin_with_token_for_another_room(mock_livekit_client)
     # Token is scoped to a DIFFERENT room, and admin status must only be
     # honored when established via session, never via a LiveKit
     # token, which can be replayed off-host.
-    token = utils.generate_token(str(other_room.id), user, is_admin_or_owner=True)
+    token = utils.generate_token(str(other_room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": target_room.id})
     response = client.post(
@@ -354,7 +354,7 @@ def test_mute_participant_admin_token_replayed_does_not_grant_admin(
         role=random.choice(["administrator", "owner"]),
     )
     # The token is the only credential.
-    token = utils.generate_token(str(room.id), admin_user, is_admin_or_owner=True)
+    token = utils.generate_token(str(room.id), admin_user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -374,7 +374,7 @@ def test_mute_participant_livekit_token_triggers_presence_check(mock_livekit_cli
     room = RoomFactory()
 
     user = AnonymousUser()
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -405,7 +405,7 @@ def test_mute_participant_livekit_token_presence_check_returns_participant(
     )
 
     user = AnonymousUser()
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -433,7 +433,7 @@ def test_mute_participant_livekit_token_presence_check_participant_not_found(
     )
 
     user = AnonymousUser()
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(
@@ -462,7 +462,7 @@ def test_mute_participant_livekit_token_presence_check_twirp_error_forbidden(
     )
 
     user = AnonymousUser()
-    token = utils.generate_token(str(room.id), user, is_admin_or_owner=False)
+    token = utils.generate_token(str(room.id), user)
 
     url = reverse("rooms-mute-participant", kwargs={"pk": room.id})
     response = client.post(

src/backend/core/tests/rooms/test_api_rooms_retrieve.py

@@ -12,7 +12,7 @@ import pytest
 from rest_framework.test import APIClient
 
 from ...factories import RoomFactory, UserFactory, UserResourceAccessFactory
-from ...models import RoomAccessLevel
+from ...models import RoleChoices, RoomAccessLevel
 
 pytestmark = pytest.mark.django_db
 
@@ -31,7 +31,6 @@ def test_api_rooms_retrieve_anonymous_private_pk():
         "configuration": {},
         "access_level": "restricted",
         "id": str(room.id),
-        "is_administrable": False,
         "name": room.name,
         "slug": room.slug,
     }
@@ -51,7 +50,6 @@ def test_api_rooms_retrieve_anonymous_trusted_pk():
         "configuration": {},
         "access_level": "trusted",
         "id": str(room.id),
-        "is_administrable": False,
         "name": room.name,
         "slug": room.slug,
     }
@@ -70,7 +68,6 @@ def test_api_rooms_retrieve_anonymous_private_pk_no_dashes():
         "configuration": {},
         "access_level": "restricted",
         "id": str(room.id),
-        "is_administrable": False,
         "name": room.name,
         "slug": room.slug,
     }
@@ -87,7 +84,6 @@ def test_api_rooms_retrieve_anonymous_private_slug():
         "configuration": {},
         "access_level": "restricted",
         "id": str(room.id),
-        "is_administrable": False,
         "name": room.name,
         "slug": room.slug,
     }
@@ -104,7 +100,6 @@ def test_api_rooms_retrieve_anonymous_private_slug_not_normalized():
         "configuration": {},
         "access_level": "restricted",
         "id": str(room.id),
-        "is_administrable": False,
         "name": room.name,
         "slug": room.slug,
     }
@@ -214,7 +209,6 @@ def test_api_rooms_retrieve_anonymous_public(mock_token):
         "configuration": {},
         "access_level": str(room.access_level),
         "id": str(room.id),
-        "is_administrable": False,
         "livekit": {
             "url": "test_url_value",
             "room": expected_name,
@@ -261,7 +255,6 @@ def test_api_rooms_retrieve_authenticated_public(mock_token):
         "configuration": {"can_publish_sources": ["camera"]},
         "access_level": str(room.access_level),
         "id": str(room.id),
-        "is_administrable": False,
         "livekit": {
             "url": "test_url_value",
             "room": expected_name,
@@ -278,8 +271,9 @@ def test_api_rooms_retrieve_authenticated_public(mock_token):
         username=None,
         color=None,
         sources=["camera"],
-        is_admin_or_owner=False,
+        role=None,
         participant_id=None,
+        is_authenticated=True,
     )
 
 
@@ -313,7 +307,6 @@ def test_api_rooms_retrieve_authenticated_trusted(mock_token):
         "configuration": {},
         "access_level": str(room.access_level),
         "id": str(room.id),
-        "is_administrable": False,
         "livekit": {
             "url": "test_url_value",
             "room": expected_name,
@@ -330,8 +323,9 @@ def test_api_rooms_retrieve_authenticated_trusted(mock_token):
         username=None,
         color=None,
         sources=None,
-        is_admin_or_owner=False,
+        role=None,
         participant_id=None,
+        is_authenticated=True,
     )
 
 
@@ -355,7 +349,6 @@ def test_api_rooms_retrieve_authenticated():
         "configuration": {},
         "access_level": "restricted",
         "id": str(room.id),
-        "is_administrable": False,
         "name": room.name,
         "slug": room.slug,
     }
@@ -401,7 +394,6 @@ def test_api_rooms_retrieve_members(mock_token, django_assert_num_queries, setti
         "configuration": {"can_publish_sources": ["camera"]},
         "access_level": str(room.access_level),
         "id": str(room.id),
-        "is_administrable": False,
         "livekit": {
             "url": "test_url_value",
             "room": expected_name,
@@ -418,8 +410,9 @@ def test_api_rooms_retrieve_members(mock_token, django_assert_num_queries, setti
         username=None,
         color=None,
         sources=["camera"],
-        is_admin_or_owner=False,
+        role=str(RoleChoices.MEMBER),
         participant_id=None,
+        is_authenticated=True,
     )
 
 
@@ -493,7 +486,6 @@ def test_api_rooms_retrieve_administrators(
     assert content_dict == {
         "access_level": str(room.access_level),
         "id": str(room.id),
-        "is_administrable": True,
         "configuration": {},
         "livekit": {
             "url": "test_url_value",
@@ -511,6 +503,7 @@ def test_api_rooms_retrieve_administrators(
         username=None,
         color=None,
         sources=None,
-        is_admin_or_owner=True,
+        role=str(user_access.role),
         participant_id=None,
+        is_authenticated=True,
     )

src/backend/core/tests/rooms/test_api_rooms_update_participant_role.py

@@ -0,0 +1,319 @@
+"""
+Test rooms API endpoints in the Meet core app: update-participant-role.
+"""
+
+# pylint: disable=redefined-outer-name,unused-argument
+
+import uuid
+from unittest import mock
+
+import pytest
+from rest_framework.test import APIClient
+
+from ...factories import RoomFactory, UserFactory
+from ...models import ResourceAccess, RoleChoices
+from ...services.participants_management import ParticipantNotFoundException
+
+pytestmark = pytest.mark.django_db
+
+
+def test_update_participant_role_anonymous():
+    """Anonymous requesters are rejected."""
+    client = APIClient()
+    room = RoomFactory()
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": "some-identity", "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 401
+
+
+def test_update_participant_role_requires_privileges():
+    """A simple member cannot promote other participants."""
+    client = APIClient()
+    user = UserFactory()
+    room = RoomFactory(users=[(user, RoleChoices.MEMBER)])
+    client.force_login(user)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": "some-identity", "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 403
+
+
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_requester_not_in_meeting(mock_perm_pm):
+    """An admin who is not connected to the meeting is rejected."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = False
+    client = APIClient()
+    user = UserFactory()
+    room = RoomFactory(users=[(user, RoleChoices.ADMIN)])
+    client.force_login(user)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": "some-identity", "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 403
+    mock_perm_pm.return_value.check_if_in_meeting.assert_called_once_with(
+        room_name=str(room.pk), identity=str(user.sub)
+    )
+
+
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_cannot_target_self(mock_perm_pm):
+    """Requesters cannot change their own role."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    client = APIClient()
+    user = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(user, RoleChoices.ADMIN)])
+    client.force_login(user)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": user.sub, "role": "member"},
+        format="json",
+    )
+
+    assert response.status_code == 403
+    assert response.json() == {"error": "You cannot change your own role."}
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_promotes_authenticated_target(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """Promoting a connected, authenticated participant persists the role."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.return_value = True
+    mock_sync.return_value = True
+
+    client = APIClient()
+    admin = UserFactory()
+    target = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(admin, RoleChoices.OWNER)])
+    client.force_login(admin)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": str(target.sub), "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 200
+    assert response.json() == {
+        "role": "administrator",
+        "livekit_synced": True,
+    }
+    access = ResourceAccess.objects.get(resource=room, user=target)
+    assert access.role == RoleChoices.ADMIN
+    mock_sync.assert_called_once_with(
+        room_name=str(room.pk),
+        participant_identity=str(target.sub),
+        role="administrator",
+    )
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_demotes_authenticated_target(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """Demoting a connected admin back to member updates the access row."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.return_value = True
+    mock_sync.return_value = True
+
+    client = APIClient()
+    admin = UserFactory()
+    target = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(admin, RoleChoices.OWNER), (target, RoleChoices.ADMIN)])
+    client.force_login(admin)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": str(target.sub), "role": "member"},
+        format="json",
+    )
+
+    assert response.status_code == 200
+    access = ResourceAccess.objects.get(resource=room, user=target)
+    assert access.role == RoleChoices.MEMBER
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_cannot_demote_owner(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """Room owners can never be demoted."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.return_value = True
+
+    client = APIClient()
+    admin = UserFactory()
+    owner = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(admin, RoleChoices.ADMIN), (owner, RoleChoices.OWNER)])
+    client.force_login(admin)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": str(owner.sub), "role": "member"},
+        format="json",
+    )
+
+    assert response.status_code == 403
+    assert response.json() == {"error": "Room owners cannot be demoted."}
+    assert (
+        ResourceAccess.objects.get(resource=room, user=owner).role == RoleChoices.OWNER
+    )
+    mock_sync.assert_not_called()
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_anonymous_target_is_ephemeral(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """Promoting an anonymous participant should not be possible."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.return_value = True
+    mock_sync.return_value = True
+
+    client = APIClient()
+    admin = UserFactory()
+    room = RoomFactory(users=[(admin, RoleChoices.ADMIN)])
+    client.force_login(admin)
+
+    anonymous_identity = uuid.uuid4()
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": anonymous_identity, "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 404
+    assert response.json() == {
+        "error": "This participant has no user account and cannot be assigned a role."
+    }
+    assert not ResourceAccess.objects.filter(resource=room).exclude(user=admin).exists()
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_target_not_in_meeting(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """Only connected participants can be promoted or demoted."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.side_effect = (
+        ParticipantNotFoundException("Participant does not exist")
+    )
+
+    client = APIClient()
+    admin = UserFactory()
+    target = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(admin, RoleChoices.ADMIN)])
+    client.force_login(admin)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": str(target.sub), "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 404
+    assert not ResourceAccess.objects.filter(resource=room, user=target).exists()
+    mock_sync.assert_not_called()
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_is_idempotent_and_resyncs(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """Promoting an existing admin succeeds and still re-syncs LiveKit."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.return_value = True
+    mock_sync.return_value = True
+
+    client = APIClient()
+    admin = UserFactory()
+    target = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(admin, RoleChoices.OWNER), (target, RoleChoices.ADMIN)])
+    client.force_login(admin)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": str(target.sub), "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 200
+    mock_sync.assert_called_once()
+
+
+@mock.patch("core.services.room_roles.RoomRoleService._sync_livekit_role")
+@mock.patch("core.services.room_roles.ParticipantsManagement")
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_livekit_failure_reports_partial_success(
+    mock_perm_pm, mock_svc_pm, mock_sync
+):
+    """A LiveKit sync failure does not lose the persisted role."""
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    mock_svc_pm.return_value.check_if_in_meeting.return_value = True
+    mock_sync.return_value = False
+
+    client = APIClient()
+    admin = UserFactory()
+    target = UserFactory(sub=uuid.uuid4())
+    room = RoomFactory(users=[(admin, RoleChoices.OWNER)])
+    client.force_login(admin)
+
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": str(target.sub), "role": "administrator"},
+        format="json",
+    )
+
+    assert response.status_code == 200
+    assert response.json() == {
+        "role": "administrator",
+        "livekit_synced": False,
+    }
+    assert (
+        ResourceAccess.objects.get(resource=room, user=target).role == RoleChoices.ADMIN
+    )
+
+
+@mock.patch("core.api.permissions.ParticipantsManagement")
+def test_update_participant_role_rejects_owner_role(mock_perm_pm):
+    """The owner role can never be granted through this endpoint."""
+    client = APIClient()
+    admin = UserFactory()
+    room = RoomFactory(users=[(admin, RoleChoices.ADMIN)])
+    client.force_login(admin)
+
+    mock_perm_pm.return_value.check_if_in_meeting.return_value = True
+    response = client.post(
+        f"/api/v1.0/rooms/{room.id}/update-participant-role/",
+        {"participant_identity": "some-identity", "role": "owner"},
+        format="json",
+    )
+
+    assert response.status_code == 400

src/backend/core/tests/services/test_lobby.py

@@ -266,7 +266,6 @@ def test_request_entry_public_room(
         username=username,
         color=participant.color,
         configuration=room.configuration,
-        is_admin_or_owner=False,
         participant_id="test-participant-id",
     )
 
@@ -305,7 +304,6 @@ def test_request_entry_trusted_room(
         username=username,
         color=participant.color,
         configuration=room.configuration,
-        is_admin_or_owner=False,
         participant_id="test-participant-id",
     )
 
@@ -400,7 +398,6 @@ def test_request_entry_accepted_participant(
         username=username,
         color="#123456",
         configuration=room.configuration,
-        is_admin_or_owner=False,
         participant_id="test-participant-id",
     )
     lobby_service._get_participant.assert_called_once_with(room.id, participant_id)

src/backend/core/utils.py

@@ -66,8 +66,9 @@ def generate_token(
     username: Optional[str] = None,
     color: Optional[str] = None,
     sources: Optional[List[str]] = None,
-    is_admin_or_owner: bool = False,
+    role: Optional[str] = None,
     participant_id: Optional[str] = None,
+    is_authenticated: Optional[bool] = False,
 ) -> str:
     """Generate a LiveKit access token for a user in a specific room.
 
@@ -80,14 +81,16 @@ def generate_token(
                          If none, a value will be generated
         sources: (Optional[List[str]]): List of media sources the user can publish
                          If none, defaults to LIVEKIT_DEFAULT_SOURCES.
-        is_admin_or_owner (bool): Whether user has admin privileges
+        role (Optional[str]): Room's access role if any
         participant_id (Optional[str]): Stable identifier for anonymous users;
                          used as identity when user.is_anonymous.
+        is_authenticated (Optional[bool]): Is user authentified.
 
     Returns:
         str: The LiveKit JWT access token.
     """
 
+    is_admin_or_owner = role in ("owner", "administrator")
     if is_admin_or_owner:
         sources = settings.LIVEKIT_DEFAULT_SOURCES
 
@@ -128,7 +131,7 @@ def generate_token(
         .with_identity(identity)
         .with_name(display_name)
         .with_attributes(
-            {"color": color, "room_admin": "true" if is_admin_or_owner else "false"}
+            {"color": color, "room_role": role, "is_authenticated": 'true' if is_authenticated else 'false'}
         )
     )
 
@@ -139,10 +142,11 @@ def generate_livekit_config(
     room_id: str,
     user,
     username: str,
-    is_admin_or_owner: bool,
+    role: Optional[str] = None,
     color: Optional[str] = None,
     configuration: Optional[dict] = None,
     participant_id: Optional[str] = None,
+    is_authenticated: Optional[bool] = False,
 ) -> dict:
     """Generate LiveKit configuration for room access.
 
@@ -150,11 +154,12 @@ def generate_livekit_config(
         room_id: Room identifier
         user: User instance requesting access
         username: Display name in room
-        is_admin_or_owner (bool): Whether the user has admin/owner privileges for this room.
+        role (str): Room's access role if any
         color (Optional[str]): Optional color to associate with the participant.
         configuration (Optional[dict]): Room configuration dict that can override default settings.
         participant_id (Optional[str]): Stable identifier for anonymous users;
                          used as identity when user.is_anonymous.
+        is_authenticated: Optional[bool]: Is user authentified.
 
     Returns:
         dict: LiveKit configuration with URL, room and access token
@@ -173,8 +178,9 @@ def generate_livekit_config(
             username=username,
             color=color,
             sources=sources,
-            is_admin_or_owner=is_admin_or_owner,
+            role=role,
             participant_id=participant_id,
+            is_authenticated=is_authenticated,
         ),
     }
 

src/frontend/src/features/participants/components/ParticipantRow.tsx

@@ -5,7 +5,7 @@ import { Text } from '@/primitives/Text'
 import { useTranslation } from 'react-i18next'
 import { Avatar } from '@/components/Avatar'
 import { getParticipantColor } from '@/features/rooms/utils/getParticipantColor'
-import { getParticipantIsRoomAdmin } from '@/features/rooms/utils/getParticipantIsRoomAdmin'
+import { getParticipantIsRoomOwner } from '@/features/rooms/utils/getParticipantIsRoomAdminOrOwner'
 import { type LocalParticipant, type Participant, Track } from 'livekit-client'
 import { isLocal } from '@/utils/livekit'
 import {
@@ -146,7 +146,7 @@ export const ParticipantRow = ({ participant }: ParticipantListItemProps) => {
               </span>
             )}
           </Text>
-          {getParticipantIsRoomAdmin(participant) && (
+          {getParticipantIsRoomOwner(participant) && (
             <Text variant="xsNote">{t('participants.host')}</Text>
           )}
         </VStack>

src/frontend/src/features/rooms/api/ApiRoom.ts

@@ -28,3 +28,6 @@ export type ApiRoom = {
   livekit?: ApiLiveKit
   configuration?: RoomConfiguration
 }
+
+export type ParticipantRole = 'member' | 'administrator' | 'owner'
+export type AssignableParticipantRole = Exclude<ParticipantRole, 'owner'>

src/frontend/src/features/rooms/api/updateParticipantRole.ts

@@ -0,0 +1,32 @@
+import type { Participant } from 'livekit-client'
+import { fetchApi } from '@/api/fetchApi'
+import { useRoomData } from '@/features/rooms/livekit/hooks/useRoomData'
+import { AssignableParticipantRole } from '@/features/rooms/api/ApiRoom'
+
+export const useParticipantRole = () => {
+  const data = useRoomData()
+
+  const updateParticipantRole = async (
+    participant: Participant,
+    role: AssignableParticipantRole
+  ) => {
+    if (!data?.id) {
+      throw new Error('Room id is not available')
+    }
+
+    try {
+      return fetchApi(`rooms/${data.id}/update-participant-role/`, {
+        method: 'POST',
+        body: JSON.stringify({
+          participant_identity: participant.identity,
+          role: role,
+        }),
+      })
+    } catch (error) {
+      console.error(
+        `Failed to update participant's role ${participant.identity}: ${error instanceof Error ? error.message : 'Unknown error'}`
+      )
+    }
+  }
+  return { updateParticipantRole }
+}

src/frontend/src/features/rooms/livekit/hooks/useIsAdminOrOwner.ts

@@ -1,6 +1,17 @@
-import { useRoomData } from './useRoomData'
+import {
+  useParticipantAttribute,
+  useRoomContext,
+} from '@livekit/components-react'
+import { ParticipantRole } from '@/features/rooms/api/ApiRoom'
 
 export const useIsAdminOrOwner = () => {
-  const apiRoomData = useRoomData()
-  return apiRoomData?.is_administrable
+  const room = useRoomContext()
+  const localParticipant = room.localParticipant
+  const role = useParticipantAttribute('room_role', {
+    participant: localParticipant,
+  })
+  return (
+    role !== undefined &&
+    ['administrator', 'owner'].includes(role as ParticipantRole)
+  )
 }

src/frontend/src/features/rooms/livekit/hooks/usePublishSourcesManager.ts

@@ -8,7 +8,7 @@ import { useRemoteParticipants } from '@livekit/components-react'
 import { useUpdateParticipantsPermissions } from '@/features/rooms/api/updateParticipantsPermissions'
 import { useRoomData } from '@/features/rooms/livekit/hooks/useRoomData'
 import { isSubsetOf } from '@/features/rooms/utils/isSubsetOf'
-import { getParticipantIsRoomAdmin } from '@/features/rooms/utils/getParticipantIsRoomAdmin'
+import { getParticipantIsRoomAdminOrOwner } from '@/features/rooms/utils/getParticipantIsRoomAdminOrOwner'
 import Source = Track.Source
 import {
   NotificationType,
@@ -48,7 +48,7 @@ export const usePublishSourcesManager = () => {
   })
 
   const unprivilegedRemoteParticipants = remoteParticipants.filter(
-    (participant) => !getParticipantIsRoomAdmin(participant)
+    (participant) => !getParticipantIsRoomAdminOrOwner(participant)
   )
 
   const currentSources = useMemo(() => {

src/frontend/src/features/rooms/utils/getParticipantIsAuthenticated.ts

@@ -0,0 +1,8 @@
+import type { Participant } from 'livekit-client'
+
+export const getParticipantIsAuthenticated = (
+  participant: Participant
+): boolean => {
+  const isAuthenticated = participant.attributes?.is_authenticated
+  return isAuthenticated == 'true'
+}

src/frontend/src/features/rooms/utils/getParticipantIsRoomAdmin.ts

@@ -1,12 +0,0 @@
-import type { Participant } from 'livekit-client'
-
-export const getParticipantIsRoomAdmin = (
-  participant: Participant
-): boolean => {
-  const attributes = participant.attributes
-
-  if (!attributes) {
-    return false
-  }
-  return attributes?.room_admin === 'true'
-}

src/frontend/src/features/rooms/utils/getParticipantIsRoomAdminOrOwner.ts

@@ -0,0 +1,20 @@
+import type { Participant } from 'livekit-client'
+import { ParticipantRole } from '@/features/rooms/api/ApiRoom'
+
+const participantHasRoomRole = (
+  participant: Participant,
+  roles: ParticipantRole[]
+): boolean => {
+  const role = participant.attributes?.room_role
+  return role !== undefined && roles.includes(role as ParticipantRole)
+}
+
+export const getParticipantIsRoomAdmin = (participant: Participant): boolean =>
+  participantHasRoomRole(participant, ['administrator'])
+
+export const getParticipantIsRoomOwner = (participant: Participant): boolean =>
+  participantHasRoomRole(participant, ['owner'])
+
+export const getParticipantIsRoomAdminOrOwner = (
+  participant: Participant
+): boolean => participantHasRoomRole(participant, ['administrator', 'owner'])