fix(openapi): Fix empty array cases for room controller used by clients

Signed-off-by: Joas Schilling <coding@schilljs.com>
2025-12-18 05:20:50 +01:00 · 2024-11-21 14:41:46 +01:00 · 2024-11-21 14:41:46 +01:00 · 451ad1e6b7
commit 451ad1e6b7
parent 563b2f67ab
9 changed files with 241 additions and 156 deletions
--- a/lib/Controller/RoomController.php
+++ b/lib/Controller/RoomController.php
@ -13,10 +13,12 @@ use OCA\Talk\Config;
 use OCA\Talk\Events\AAttendeeRemovedEvent;
 use OCA\Talk\Events\BeforeRoomsFetchEvent;
 use OCA\Talk\Exceptions\CannotReachRemoteException;
+use OCA\Talk\Exceptions\FederationRestrictionException;
 use OCA\Talk\Exceptions\ForbiddenException;
 use OCA\Talk\Exceptions\GuestImportException;
 use OCA\Talk\Exceptions\InvalidPasswordException;
 use OCA\Talk\Exceptions\ParticipantNotFoundException;
+use OCA\Talk\Exceptions\ParticipantProperty\PermissionsException;
 use OCA\Talk\Exceptions\RoomNotFoundException;
 use OCA\Talk\Exceptions\RoomProperty\DefaultPermissionsException;
 use OCA\Talk\Exceptions\RoomProperty\DescriptionException;
@ -177,7 +179,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * @param bool $includeStatus Include the user status
 	 * @param int $modifiedSince Filter rooms modified after a timestamp
 	 * @psalm-param non-negative-int $modifiedSince
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom[], array{X-Nextcloud-Talk-Hash: string, X-Nextcloud-Talk-Modified-Before: numeric-string, X-Nextcloud-Talk-Federation-Invites?: numeric-string}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkRoom>, array{X-Nextcloud-Talk-Hash: string, X-Nextcloud-Talk-Modified-Before: numeric-string, X-Nextcloud-Talk-Federation-Invites?: numeric-string}>
 	 *
 	 * 200: Return list of rooms
 	 */
@ -286,7 +288,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * Get listed rooms with optional search term
 	 *
 	 * @param string $searchTerm search term
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom[], array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkRoom>, array{}>
 	 *
 	 * 200: Return list of matching rooms
 	 */
@ -307,7 +309,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * All for moderators and in case of "free selection", or the assigned breakout room for other participants
 	 *
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom[], array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: string}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkRoom>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: string}, array{}>
 	 *
 	 * 200: Breakout rooms returned
 	 * 400: Getting breakout rooms is not possible
@ -503,7 +505,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * @param string $objectType Type of the object
 	 * @param string $objectId ID of the object
 	 * @param string $password The room password (only available with `conversation-creation-password` capability)
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error?: string, message?: string}, array{}>|DataResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array{error: 'invite'|'mode'|'object'|'password'|'permissions'|'room'|'type', message?: string}, array{}>
 	 *
 	 * 200: Room already existed
 	 * 201: Room created successfully
@ -526,7 +528,7 @@ class RoomController extends AEnvironmentAwareController {
 			$user = $this->userManager->get($this->userId);

 			if ($this->talkConfig->isNotAllowedToCreateConversations($user)) {
-				return new DataResponse([], Http::STATUS_FORBIDDEN);
+				return new DataResponse(['error' => 'permissions'], Http::STATUS_FORBIDDEN);
 			}
 		}

@ -545,29 +547,30 @@ class RoomController extends AEnvironmentAwareController {
 				return $this->createEmptyRoom($roomName, true, $objectType, $objectId, $password);
 		}

-		return new DataResponse([], Http::STATUS_BAD_REQUEST);
+		return new DataResponse(['error' => 'type'], Http::STATUS_BAD_REQUEST);
 	}

 	/**
 	 * Initiates a one-to-one video call from the current user to the recipient
 	 *
 	 * @param string $targetUserId ID of the user
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array{error: 'invite'}, array{}>
 	 */
 	#[NoAdminRequired]
 	protected function createOneToOneRoom(string $targetUserId): DataResponse {
 		$currentUser = $this->userManager->get($this->userId);
 		if (!$currentUser instanceof IUser) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			// Should never happen, basically an internal server error so we reuse another error
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		if ($targetUserId === MatterbridgeManager::BRIDGE_BOT_USERID) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		$targetUser = $this->userManager->get($targetUserId);
 		if (!$targetUser instanceof IUser) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		try {
@ -590,9 +593,9 @@ class RoomController extends AEnvironmentAwareController {
 			);
 		} catch (\InvalidArgumentException $e) {
 			// Same current and target user
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_FORBIDDEN);
 		} catch (RoomNotFoundException $e) {
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_FORBIDDEN);
 		}
 	}

@ -600,18 +603,19 @@ class RoomController extends AEnvironmentAwareController {
 	 * Initiates a group video call from the selected group
 	 *
 	 * @param string $targetGroupName
-	 * @return DataResponse<Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_NOT_FOUND, array{error: 'invite'}, array{}>
 	 */
 	#[NoAdminRequired]
 	protected function createGroupRoom(string $targetGroupName): DataResponse {
 		$currentUser = $this->userManager->get($this->userId);
 		if (!$currentUser instanceof IUser) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			// Should never happen, basically an internal server error so we reuse another error
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		$targetGroup = $this->groupManager->get($targetGroupName);
 		if (!$targetGroup instanceof IGroup) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		// Create the room
@ -626,23 +630,24 @@ class RoomController extends AEnvironmentAwareController {
 	 * Initiates a group video call from the selected circle
 	 *
 	 * @param string $targetCircleId
-	 * @return DataResponse<Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error?: string}, array{}>|DataResponse<Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array{error: 'invite'}, array{}>
 	 */
 	#[NoAdminRequired]
 	protected function createCircleRoom(string $targetCircleId): DataResponse {
 		if (!$this->appManager->isEnabledForUser('circles')) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_BAD_REQUEST);
 		}

 		$currentUser = $this->userManager->get($this->userId);
 		if (!$currentUser instanceof IUser) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			// Should never happen, basically an internal server error so we reuse another error
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		try {
 			$circle = $this->participantService->getCircle($targetCircleId, $this->userId);
 		} catch (\Exception $e) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		// Create the room
@ -654,13 +659,14 @@ class RoomController extends AEnvironmentAwareController {
 	}

 	/**
-	 * @return DataResponse<Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error?: string, message?: string}, array{}>|DataResponse<Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_CREATED, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array{error: 'invite'|'mode'|'object'|'password'|'permissions'|'room', message?: string}, array{}>
 	 */
 	#[NoAdminRequired]
 	protected function createEmptyRoom(string $roomName, bool $public = true, string $objectType = '', string $objectId = '', string $password = ''): DataResponse {
 		$currentUser = $this->userManager->get($this->userId);
 		if (!$currentUser instanceof IUser) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			// Should never happen, basically an internal server error so we reuse another error
+			return new DataResponse(['error' => 'invite'], Http::STATUS_NOT_FOUND);
 		}

 		$roomType = $public ? Room::TYPE_PUBLIC : Room::TYPE_GROUP;
@ -725,7 +731,7 @@ class RoomController extends AEnvironmentAwareController {
 	/**
 	 * Add a room to the favorites
 	 *
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>
 	 *
 	 * 200: Successfully added room to favorites
 	 */
@ -734,13 +740,13 @@ class RoomController extends AEnvironmentAwareController {
 	#[RequireLoggedInParticipant]
 	public function addToFavorites(): DataResponse {
 		$this->participantService->updateFavoriteStatus($this->participant, true);
-		return new DataResponse([]);
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
 	 * Remove a room from the favorites
 	 *
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>
 	 *
 	 * 200: Successfully removed room from favorites
 	 */
@ -749,7 +755,7 @@ class RoomController extends AEnvironmentAwareController {
 	#[RequireLoggedInParticipant]
 	public function removeFromFavorites(): DataResponse {
 		$this->participantService->updateFavoriteStatus($this->participant, false);
-		return new DataResponse([]);
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -757,7 +763,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int $level New level
 	 * @psalm-param Participant::NOTIFY_* $level
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'level'}, array{}>
 	 *
 	 * 200: Notification level updated successfully
 	 * 400: Updating notification level is not possible
@ -768,11 +774,11 @@ class RoomController extends AEnvironmentAwareController {
 	public function setNotificationLevel(int $level): DataResponse {
 		try {
 			$this->participantService->updateNotificationLevel($this->participant, $level);
-		} catch (\InvalidArgumentException $e) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+		} catch (\InvalidArgumentException) {
+			return new DataResponse(['error' => 'level'], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -780,7 +786,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int $level New level
 	 * @psalm-param Participant::NOTIFY_CALLS_* $level
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'level'}, array{}>
 	 *
 	 * 200: Call notification level updated successfully
 	 * 400: Updating call notification level is not possible
@ -790,18 +796,18 @@ class RoomController extends AEnvironmentAwareController {
 	public function setNotificationCalls(int $level): DataResponse {
 		try {
 			$this->participantService->updateNotificationCalls($this->participant, $level);
-		} catch (\InvalidArgumentException $e) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+		} catch (\InvalidArgumentException) {
+			return new DataResponse(['error' => 'level'], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
 	 * Rename a room
 	 *
 	 * @param string $roomName New name
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'type'|'value'}, array{}>
 	 *
 	 * 200: Room renamed successfully
 	 * 400: Renaming room is not possible
@ -814,14 +820,14 @@ class RoomController extends AEnvironmentAwareController {
 		} catch (NameException $e) {
 			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}
-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
 	 * Update the description of a room
 	 *
 	 * @param string $description New description
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'type'|'value'}, array{}>
 	 *
 	 * 200: Description updated successfully
 	 * 400: Updating description is not possible
@ -835,13 +841,13 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
 	 * Delete a room
 	 *
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST, null, array{}>
 	 *
 	 * 200: Room successfully deleted
 	 * 400: Deleting room is not possible
@ -850,12 +856,12 @@ class RoomController extends AEnvironmentAwareController {
 	#[RequireModeratorParticipant]
 	public function deleteRoom(): DataResponse {
 		if ($this->room->getType() === Room::TYPE_ONE_TO_ONE || $this->room->getType() === Room::TYPE_ONE_TO_ONE_FORMER) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(null, Http::STATUS_BAD_REQUEST);
 		}

 		$this->roomService->deleteRoom($this->room);

-		return new DataResponse([]);
+		return new DataResponse(null);
 	}

 	/**
@ -863,7 +869,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * Get a list of participants for a room
 	 *
 	 * @param bool $includeStatus Include the user statuses
-	 * @return DataResponse<Http::STATUS_OK, TalkParticipant[], array{X-Nextcloud-Has-User-Statuses?: bool}>|DataResponse<Http::STATUS_FORBIDDEN, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkParticipant>, array{X-Nextcloud-Has-User-Statuses?: bool}>|DataResponse<Http::STATUS_FORBIDDEN, null, array{}>
 	 *
 	 * 200: Participants returned
 	 * 403: Missing permissions for getting participants
@ -916,7 +922,7 @@ class RoomController extends AEnvironmentAwareController {
 		}

 		if ($this->participant->getAttendee()->getParticipantType() === Participant::GUEST) {
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			return new DataResponse(null, Http::STATUS_FORBIDDEN);
 		}

 		$participants = $this->participantService->getSessionsAndParticipantsForRoom($this->room);
@ -928,7 +934,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * Get the breakout room participants for a room
 	 *
 	 * @param bool $includeStatus Include the user statuses
-	 * @return DataResponse<Http::STATUS_OK, TalkParticipant[], array{X-Nextcloud-Has-User-Statuses?: bool}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: string}, array{}>|DataResponse<Http::STATUS_FORBIDDEN, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkParticipant>, array{X-Nextcloud-Has-User-Statuses?: bool}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: string}, array{}>|DataResponse<Http::STATUS_FORBIDDEN, null, array{}>
 	 *
 	 * 200: Breakout room participants returned
 	 * 400: Getting breakout room participants is not possible
@ -939,7 +945,7 @@ class RoomController extends AEnvironmentAwareController {
 	#[RequireParticipant]
 	public function getBreakoutRoomParticipants(bool $includeStatus = false): DataResponse {
 		if ($this->participant->getAttendee()->getParticipantType() === Participant::GUEST) {
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			return new DataResponse(null, Http::STATUS_FORBIDDEN);
 		}

 		try {
@ -1131,7 +1137,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param string $newParticipant New participant
 	 * @param 'users'|'groups'|'circles'|'emails'|'federated_users'|'phones' $source Source of the participant
-	 * @return DataResponse<Http::STATUS_OK, array{type: int}|array<empty>, array{}>|DataResponse<Http::STATUS_NOT_FOUND|Http::STATUS_NOT_IMPLEMENTED, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error?: string}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, array{type?: int}, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND|Http::STATUS_NOT_IMPLEMENTED, array{error: 'ban'|'cloud-id'|'federation'|'moderator'|'new-participant'|'outgoing'|'reach-remote'|'room-type'|'sip'|'source'|'trusted-servers'}, array{}>
 	 *
 	 * 200: Participant successfully added
 	 * 400: Adding participant is not possible, e.g. when the user is banned (check error attribute of response for detail key)
@ -1145,7 +1151,7 @@ class RoomController extends AEnvironmentAwareController {
 			|| $this->room->getType() === Room::TYPE_ONE_TO_ONE_FORMER
 			|| $this->room->getType() === Room::TYPE_NOTE_TO_SELF
 			|| $this->room->getObjectType() === Room::OBJECT_TYPE_VIDEO_VERIFICATION) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(['error' => 'room-type'], Http::STATUS_BAD_REQUEST);
 		}

 		if ($source !== 'users' && $this->room->getObjectType() === BreakoutRoom::PARENT_OBJECT_TYPE) {
@ -1173,12 +1179,12 @@ class RoomController extends AEnvironmentAwareController {

 		if ($source === 'users') {
 			if ($newParticipant === MatterbridgeManager::BRIDGE_BOT_USERID) {
-				return new DataResponse([], Http::STATUS_NOT_FOUND);
+				return new DataResponse(['error' => 'new-participant'], Http::STATUS_NOT_FOUND);
 			}

 			$newUser = $this->userManager->get($newParticipant);
 			if (!$newUser instanceof IUser) {
-				return new DataResponse([], Http::STATUS_NOT_FOUND);
+				return new DataResponse(['error' => 'new-participant'], Http::STATUS_NOT_FOUND);
 			}

 			//Check if the user is banned
@ -1194,19 +1200,19 @@ class RoomController extends AEnvironmentAwareController {
 		} elseif ($source === 'groups') {
 			$group = $this->groupManager->get($newParticipant);
 			if (!$group instanceof IGroup) {
-				return new DataResponse([], Http::STATUS_NOT_FOUND);
+				return new DataResponse(['error' => 'new-participant'], Http::STATUS_NOT_FOUND);
 			}

 			$this->participantService->addGroup($this->room, $group, $participants);
 		} elseif ($source === 'circles') {
 			if (!$this->appManager->isEnabledForUser('circles')) {
-				return new DataResponse([], Http::STATUS_BAD_REQUEST);
+				return new DataResponse(['error' => 'new-participant'], Http::STATUS_BAD_REQUEST);
 			}

 			try {
 				$circle = $this->participantService->getCircle($newParticipant, $this->userId);
-			} catch (\Exception $e) {
-				return new DataResponse([], Http::STATUS_NOT_FOUND);
+			} catch (\Exception) {
+				return new DataResponse(['error' => 'new-participant'], Http::STATUS_NOT_FOUND);
 			}

 			$this->participantService->addCircle($this->room, $circle, $participants);
@ -1230,7 +1236,7 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse($data);
 		} elseif ($source === 'federated_users') {
 			if (!$this->talkConfig->isFederationEnabled()) {
-				return new DataResponse([], Http::STATUS_NOT_IMPLEMENTED);
+				return new DataResponse(['error' => 'federation'], Http::STATUS_NOT_IMPLEMENTED);
 			}
 			try {
 				$newUser = $this->cloudIdManager->resolveCloudId($newParticipant);
@ -1238,12 +1244,12 @@ class RoomController extends AEnvironmentAwareController {
 				$this->logger->error($e->getMessage(), [
 					'exception' => $e,
 				]);
-				return new DataResponse(['error' => 'cloudId'], Http::STATUS_BAD_REQUEST);
+				return new DataResponse(['error' => 'cloud-id'], Http::STATUS_BAD_REQUEST);
 			}
 			try {
 				$this->federationManager->isAllowedToInvite($addedBy, $newUser);
-			} catch (\InvalidArgumentException $e) {
-				return new DataResponse(['error' => $e->getMessage()], Http::STATUS_BAD_REQUEST);
+			} catch (FederationRestrictionException $e) {
+				return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 			}

 			$participantsToAdd[] = [
@ -1258,7 +1264,7 @@ class RoomController extends AEnvironmentAwareController {
 				|| !$this->talkConfig->canUserDialOutSIP($addedBy)
 				|| preg_match(Room::SIP_INCOMPATIBLE_REGEX, $this->room->getToken())
 				|| ($this->room->getType() !== Room::TYPE_GROUP && $this->room->getType() !== Room::TYPE_PUBLIC)) {
-				return new DataResponse([], Http::STATUS_NOT_IMPLEMENTED);
+				return new DataResponse(['error' => 'sip'], Http::STATUS_NOT_IMPLEMENTED);
 			}

 			$phoneRegion = $this->config->getSystemValueString('default_phone_region');
@ -1279,7 +1285,7 @@ class RoomController extends AEnvironmentAwareController {
 			];
 		} else {
 			$this->logger->error('Trying to add participant from unsupported source ' . $source);
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(['error' => 'source'], Http::STATUS_BAD_REQUEST);
 		}

 		// attempt adding the listed users to the room
@ -1318,7 +1324,9 @@ class RoomController extends AEnvironmentAwareController {
 			try {
 				$this->breakoutRoomService->removeAttendeeFromBreakoutRoom($parentRoom, Attendee::ACTOR_USERS, $newParticipant);
 			} catch (\InvalidArgumentException $e) {
-				return new DataResponse(['error' => $e->getMessage()], Http::STATUS_BAD_REQUEST);
+				/** @var 'moderator' $error */
+				$error = $e->getMessage();
+				return new DataResponse(['error' => $error], Http::STATUS_BAD_REQUEST);
 			}
 		}

@ -1326,7 +1334,7 @@ class RoomController extends AEnvironmentAwareController {
 		try {
 			$this->participantService->addUsers($this->room, $participantsToAdd, $addedBy);
 		} catch (CannotReachRemoteException $e) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'reach-remote'], Http::STATUS_NOT_FOUND);
 		}

 		return new DataResponse([]);
@ -1335,7 +1343,7 @@ class RoomController extends AEnvironmentAwareController {
 	/**
 	 * Remove the current user from a room
 	 *
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, null, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array{error: 'last-moderator'|'participant'}, array{}> *
 	 *
 	 * 200: Participant removed successfully
 	 * 400: Removing participant is not possible
@ -1349,7 +1357,7 @@ class RoomController extends AEnvironmentAwareController {
 	}

 	/**
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, null, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array{error: 'last-moderator'|'participant'}, array{}>
 	 */
 	protected function removeSelfFromRoomLogic(Room $room, Participant $participant): DataResponse {
 		if ($room->isFederatedConversation()) {
@ -1360,7 +1368,7 @@ class RoomController extends AEnvironmentAwareController {
 			if ($participant->hasModeratorPermissions(false)
 				&& $this->participantService->getNumberOfUsers($room) > 1
 				&& $this->participantService->getNumberOfModerators($room) === 1) {
-				return new DataResponse([], Http::STATUS_BAD_REQUEST);
+				return new DataResponse(['error' => 'last-moderator'], Http::STATUS_BAD_REQUEST);
 			}
 		}

@ -1373,17 +1381,17 @@ class RoomController extends AEnvironmentAwareController {
 				Participant::OWNER,
 			], true)) {
 			$this->roomService->deleteRoom($room);
-			return new DataResponse();
+			return new DataResponse(null);
 		}

 		$currentUser = $this->userManager->get($this->userId);
 		if (!$currentUser instanceof IUser) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'participant'], Http::STATUS_NOT_FOUND);
 		}

 		$this->participantService->removeUser($room, $currentUser, AAttendeeRemovedEvent::REASON_LEFT);

-		return new DataResponse();
+		return new DataResponse(null);
 	}

 	/**
@ -1391,7 +1399,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int $attendeeId ID of the attendee
 	 * @psalm-param non-negative-int $attendeeId
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, null, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array{error: 'last-moderator'|'owner'|'participant'|'room-type'}, array{}>
 	 *
 	 * 200: Attendee removed successfully
 	 * 400: Removing attendee is not possible
@ -1404,16 +1412,16 @@ class RoomController extends AEnvironmentAwareController {
 		try {
 			$targetParticipant = $this->participantService->getParticipantByAttendeeId($this->room, $attendeeId);
 		} catch (ParticipantNotFoundException $e) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'participant'], Http::STATUS_NOT_FOUND);
 		}

 		if ($targetParticipant->getAttendee()->getActorType() === Attendee::ACTOR_USERS
 			&& $targetParticipant->getAttendee()->getActorId() === MatterbridgeManager::BRIDGE_BOT_USERID) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'participant'], Http::STATUS_NOT_FOUND);
 		}

 		if ($this->room->getType() === Room::TYPE_ONE_TO_ONE || $this->room->getType() === Room::TYPE_ONE_TO_ONE_FORMER) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(['error' => 'room-type'], Http::STATUS_BAD_REQUEST);
 		}

 		if ($this->participant->getAttendee()->getId() === $targetParticipant->getAttendee()->getId()) {
@ -1421,11 +1429,11 @@ class RoomController extends AEnvironmentAwareController {
 		}

 		if ($targetParticipant->getAttendee()->getParticipantType() === Participant::OWNER) {
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			return new DataResponse(['error' => 'owner'], Http::STATUS_FORBIDDEN);
 		}

 		$this->participantService->removeAttendee($this->room, $targetParticipant, AAttendeeRemovedEvent::REASON_REMOVED);
-		return new DataResponse([]);
+		return new DataResponse(null);
 	}

 	/**
@ -1434,7 +1442,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * Required capability: `conversation-creation-password` for `string $password` parameter
 	 *
 	 * @param string $password New password (only available with `conversation-creation-password` capability)
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'|'password', message?: null|string}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'|'password', message?: string}, array{}>
 	 *
 	 * 200: Allowed guests successfully
 	 * 400: Allowing guests is not possible
@ -1458,13 +1466,13 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
 	 * Disallowed guests to join conversation
 	 *
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'}, array{}>
 	 *
 	 * 200: Room unpublished Disallowing guests successfully
 	 * 400: Disallowing guests is not possible
@ -1478,7 +1486,7 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -1486,7 +1494,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param 0|1 $state New read-only state
 	 * @psalm-param Room::READ_* $state
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'type'|'value'}, array{}>
 	 *
 	 * 200: Read-only state updated successfully
 	 * 400: Updating read-only state is not possible
@ -1509,7 +1517,7 @@ class RoomController extends AEnvironmentAwareController {
 			}
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -1517,7 +1525,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param 0|1|2 $scope Scope where the room is listable
 	 * @psalm-param Room::LISTABLE_* $scope
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'}, array{}>
 	 *
 	 * 200: Made room listable successfully
 	 * 400: Making room listable is not possible
@ -1531,7 +1539,7 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -1560,7 +1568,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * Set a password for a room
 	 *
 	 * @param string $password New password
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value', message?: string}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value', message?: string}, array{}>
 	 *
 	 * 200: Password set successfully
 	 * 400: Setting password is not possible
@ -1578,7 +1586,7 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse($data, Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -1621,7 +1629,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * @param string $token Token of the room
 	 * @param string $password Password of the room
 	 * @param bool $force Create a new session if necessary
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{X-Nextcloud-Talk-Proxy-Hash?: string}>|DataResponse<Http::STATUS_FORBIDDEN, array{error: 'ban'|'password'}, array<empty>>|DataResponse<Http::STATUS_NOT_FOUND, array<empty>, array<empty>>|DataResponse<Http::STATUS_CONFLICT, array{sessionId: string, inCall: int, lastPing: int}, array<empty>>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{X-Nextcloud-Talk-Proxy-Hash?: string}>|DataResponse<Http::STATUS_FORBIDDEN, array{error: 'ban'|'password'}, array{}>|DataResponse<Http::STATUS_NOT_FOUND, null, array{}>|DataResponse<Http::STATUS_CONFLICT, array{sessionId: string, inCall: int, lastPing: int}, array{}>
 	 *
 	 * 200: Room joined successfully
 	 * 403: Joining room is not allowed
@ -1637,7 +1645,7 @@ class RoomController extends AEnvironmentAwareController {
 			// The participant is just joining, so enforce to not load any session
 			$room = $this->manager->getRoomForUserByToken($token, $this->userId, null);
 		} catch (RoomNotFoundException $e) {
-			$response = new DataResponse([], Http::STATUS_NOT_FOUND);
+			$response = new DataResponse(null, Http::STATUS_NOT_FOUND);
 			$response->throttle(['token' => $token, 'action' => 'talkRoomToken']);
 			return $response;
 		}
@ -1721,7 +1729,7 @@ class RoomController extends AEnvironmentAwareController {
 			$response->throttle(['token' => $token, 'action' => 'talkRoomPassword']);
 			return $response;
 		} catch (UnauthorizedException $e) {
-			$response = new DataResponse([], Http::STATUS_NOT_FOUND);
+			$response = new DataResponse(null, Http::STATUS_NOT_FOUND);
 			$response->throttle(['token' => $token, 'action' => 'talkRoomToken']);
 			return $response;
 		}
@ -1746,7 +1754,7 @@ class RoomController extends AEnvironmentAwareController {

 			if ($response->getStatus() === Http::STATUS_NOT_FOUND) {
 				$this->participantService->removeAttendee($room, $participant, AAttendeeRemovedEvent::REASON_REMOVED);
-				return new DataResponse([], Http::STATUS_NOT_FOUND);
+				return new DataResponse(null, Http::STATUS_NOT_FOUND);
 			}

 			/** @var TalkRoom $data */
@ -1996,7 +2004,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param 0|1 $state of the room
 	 * @psalm-param Session::STATE_* $state
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_NOT_FOUND, null, array{}>
 	 *
 	 * 200: Session state set successfully
 	 * 400: The provided new state was invalid
@ -2007,13 +2015,13 @@ class RoomController extends AEnvironmentAwareController {
 	#[RequireParticipant]
 	public function setSessionState(int $state): DataResponse {
 		if (!$this->participant->getSession() instanceof Session) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(null, Http::STATUS_NOT_FOUND);
 		}

 		try {
 			$this->sessionService->updateSessionState($this->participant->getSession(), $state);
 		} catch (\InvalidArgumentException) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(null, Http::STATUS_BAD_REQUEST);
 		}

 		return new DataResponse($this->formatRoom($this->room, $this->participant));
@ -2023,7 +2031,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * Leave a room
 	 *
 	 * @param string $token Token of the room
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, null, array{}>
 	 *
 	 * 200: Successfully left the room
 	 */
@ -2046,7 +2054,7 @@ class RoomController extends AEnvironmentAwareController {
 		} catch (RoomNotFoundException|ParticipantNotFoundException) {
 		}

-		return new DataResponse();
+		return new DataResponse(null);
 	}

 	/**
@ -2054,7 +2062,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param string $token Token of the room
 	 * @param string $sessionId Federated session id to leave with
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_NOT_FOUND, null, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_NOT_FOUND, null, array{}>
 	 *
 	 * 200: Successfully left the room
 	 * 404: Room not found (non-federation request)
@ -2095,7 +2103,7 @@ class RoomController extends AEnvironmentAwareController {
 		} catch (RoomNotFoundException|ParticipantNotFoundException) {
 		}

-		return new DataResponse();
+		return new DataResponse(null);
 	}

 	/**
@ -2103,7 +2111,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int $attendeeId ID of the attendee
 	 * @psalm-param non-negative-int $attendeeId
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, null, array{}>
 	 *
 	 * 200: Attendee promoted to moderator successfully
 	 * 400: Promoting attendee to moderator is not possible
@ -2121,7 +2129,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int $attendeeId ID of the attendee
 	 * @psalm-param non-negative-int $attendeeId
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, null, array{}>
 	 *
 	 * 200: Attendee demoted from moderator successfully
 	 * 400: Demoting attendee from moderator is not possible
@ -2141,35 +2149,35 @@ class RoomController extends AEnvironmentAwareController {
 	 * @param int $attendeeId
 	 * @psalm-param non-negative-int $attendeeId
 	 * @param bool $promote Shall the attendee be promoted or demoted
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, null, array{}>
 	 */
 	protected function changeParticipantType(int $attendeeId, bool $promote): DataResponse {
 		try {
 			$targetParticipant = $this->participantService->getParticipantByAttendeeId($this->room, $attendeeId);
 		} catch (ParticipantNotFoundException $e) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(null, Http::STATUS_NOT_FOUND);
 		}

 		$attendee = $targetParticipant->getAttendee();

 		if ($attendee->getActorType() === Attendee::ACTOR_USERS
 			&& $attendee->getActorId() === MatterbridgeManager::BRIDGE_BOT_USERID) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(null, Http::STATUS_NOT_FOUND);
 		}

 		// Prevent users/moderators modifying themselves
 		if ($attendee->getActorType() === $this->participant->getAttendee()->getActorType()) {
 			if ($attendee->getActorId() === $this->participant->getAttendee()->getActorId()) {
-				return new DataResponse([], Http::STATUS_FORBIDDEN);
+				return new DataResponse(null, Http::STATUS_FORBIDDEN);
 			}
 		} elseif ($attendee->getActorType() === Attendee::ACTOR_GROUPS) {
 			// Can not promote/demote groups
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(null, Http::STATUS_BAD_REQUEST);
 		}

 		if ($promote === $targetParticipant->hasModeratorPermissions()) {
 			// Prevent concurrent changes
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(null, Http::STATUS_BAD_REQUEST);
 		}

 		if ($attendee->getParticipantType() === Participant::USER) {
@ -2181,12 +2189,12 @@ class RoomController extends AEnvironmentAwareController {
 		} elseif ($attendee->getParticipantType() === Participant::GUEST_MODERATOR) {
 			$newType = Participant::GUEST;
 		} else {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
+			return new DataResponse(null, Http::STATUS_BAD_REQUEST);
 		}

 		$this->participantService->updateParticipantType($this->room, $targetParticipant, $newType);

-		return new DataResponse();
+		return new DataResponse(null);
 	}

 	/**
@ -2224,7 +2232,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * @param 'set'|'remove'|'add' $method Method of updating permissions ('set', 'remove', 'add')
 	 * @param int<0, 255> $permissions New permissions
 	 * @psalm-param int-mask-of<Attendee::PERMISSIONS_*> $permissions
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkParticipant>, array{X-Nextcloud-Has-User-Statuses?: true}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_FORBIDDEN|Http::STATUS_NOT_FOUND, array{error: 'participant'|'method'|'moderator'|'room-type'|'type'|'value'}, array{}>
 	 *
 	 * 200: Permissions updated successfully
 	 * 400: Updating permissions is not possible
@ -2237,20 +2245,19 @@ class RoomController extends AEnvironmentAwareController {
 		try {
 			$targetParticipant = $this->participantService->getParticipantByAttendeeId($this->room, $attendeeId);
 		} catch (ParticipantNotFoundException $e) {
-			return new DataResponse([], Http::STATUS_NOT_FOUND);
+			return new DataResponse(['error' => 'participant'], Http::STATUS_NOT_FOUND);
 		}

 		try {
-			$result = $this->participantService->updatePermissions($this->room, $targetParticipant, $method, $permissions);
-		} catch (ForbiddenException $e) {
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			$this->participantService->updatePermissions($this->room, $targetParticipant, $method, $permissions);
+		} catch (PermissionsException $e) {
+			if ($e->getReason() === PermissionsException::REASON_MODERATOR) {
+				return new DataResponse(['error' => $e->getReason()], Http::STATUS_FORBIDDEN);
+			}
+			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}

-		if (!$result) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
-		}
-
-		return new DataResponse();
+		return $this->formatParticipantList([$targetParticipant], true);
 	}

 	/**
@ -2260,7 +2267,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * @psalm-param Attendee::PERMISSIONS_MODIFY_* $method
 	 * @param int<0, 255> $permissions New permissions
 	 * @psalm-param int-mask-of<Attendee::PERMISSIONS_*> $permissions
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, null, array{}>
 	 * @deprecated Call permissions have been removed
 	 *
 	 * 200: Permissions updated successfully
@ -2269,11 +2276,7 @@ class RoomController extends AEnvironmentAwareController {
 	#[PublicPage]
 	#[RequireModeratorParticipant]
 	public function setAllAttendeesPermissions(string $method, int $permissions): DataResponse {
-		if (!$this->roomService->setPermissions($this->room, 'call', $method, $permissions, false)) {
-			return new DataResponse([], Http::STATUS_BAD_REQUEST);
-		}
-
-		return new DataResponse($this->formatRoom($this->room, $this->participant));
+		return new DataResponse(null, Http::STATUS_BAD_REQUEST);
 	}

 	/**
@ -2331,7 +2334,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param 0|1|2 $state New state
 	 * @psalm-param Webinary::SIP_* $state
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_UNAUTHORIZED|Http::STATUS_FORBIDDEN|Http::STATUS_PRECONDITION_FAILED, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'token'|'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_UNAUTHORIZED|Http::STATUS_FORBIDDEN|Http::STATUS_PRECONDITION_FAILED, array{error: 'config'}, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'token'|'type'|'value'}, array{}>
 	 *
 	 * 200: SIP enabled state updated successfully
 	 * 400: Updating SIP enabled state is not possible
@ -2344,15 +2347,15 @@ class RoomController extends AEnvironmentAwareController {
 	public function setSIPEnabled(int $state): DataResponse {
 		$user = $this->userManager->get($this->userId);
 		if (!$user instanceof IUser) {
-			return new DataResponse([], Http::STATUS_UNAUTHORIZED);
+			return new DataResponse(['error' => 'config'], Http::STATUS_UNAUTHORIZED);
 		}

 		if (!$this->talkConfig->canUserEnableSIP($user)) {
-			return new DataResponse([], Http::STATUS_FORBIDDEN);
+			return new DataResponse(['error' => 'config'], Http::STATUS_FORBIDDEN);
 		}

 		if (!$this->talkConfig->isSIPConfigured()) {
-			return new DataResponse([], Http::STATUS_PRECONDITION_FAILED);
+			return new DataResponse(['error' => 'config'], Http::STATUS_PRECONDITION_FAILED);
 		}

 		try {
@ -2370,7 +2373,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * @param int $recordingConsent New consent setting for the conversation
 	 *                              (Only {@see RecordingService::CONSENT_REQUIRED_NO} and {@see RecordingService::CONSENT_REQUIRED_YES} are allowed here.)
 	 * @psalm-param RecordingService::CONSENT_REQUIRED_NO|RecordingService::CONSENT_REQUIRED_YES $recordingConsent
-	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'call'|'value'}, array{}>|DataResponse<Http::STATUS_PRECONDITION_FAILED, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'call'|'value'}, array{}>|DataResponse<Http::STATUS_PRECONDITION_FAILED, array{error: 'config'}, array{}>
 	 *
 	 * 200: Recording consent requirement set successfully
 	 * 400: Setting recording consent requirement is not possible
@ -2380,7 +2383,7 @@ class RoomController extends AEnvironmentAwareController {
 	#[RequireLoggedInModeratorParticipant]
 	public function setRecordingConsent(int $recordingConsent): DataResponse {
 		if (!$this->talkConfig->isRecordingEnabled()) {
-			return new DataResponse([], Http::STATUS_PRECONDITION_FAILED);
+			return new DataResponse(['error' => 'config'], Http::STATUS_PRECONDITION_FAILED);
 		}

 		try {
@ -2397,7 +2400,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int|null $attendeeId ID of the attendee
 	 * @psalm-param non-negative-int|null $attendeeId
-	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_NOT_FOUND, array<empty>, array{}>
+	 * @return DataResponse<Http::STATUS_OK|Http::STATUS_NOT_FOUND, null, array{}>
 	 *
 	 * 200: Invitation resent successfully
 	 * 404: Attendee not found
@ -2413,7 +2416,7 @@ class RoomController extends AEnvironmentAwareController {
 			try {
 				$participants[] = $this->participantService->getParticipantByAttendeeId($this->room, $attendeeId);
 			} catch (ParticipantNotFoundException $e) {
-				return new DataResponse([], Http::STATUS_NOT_FOUND);
+				return new DataResponse(null, Http::STATUS_NOT_FOUND);
 			}
 		} else {
 			$participants = $this->participantService->getParticipantsByActorType($this->room, Attendee::ACTOR_EMAILS);
@ -2426,7 +2429,7 @@ class RoomController extends AEnvironmentAwareController {
 				$this->guestManager->sendEmailInvitation($this->room, $participant);
 			}
 		}
-		return new DataResponse();
+		return new DataResponse(null);
 	}

 	/**
@ -2434,7 +2437,7 @@ class RoomController extends AEnvironmentAwareController {
 	 *
 	 * @param int $seconds New time
 	 * @psalm-param non-negative-int $seconds
-	 * @return DataResponse<Http::STATUS_OK, array<empty>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'}, array{}>
+	 * @return DataResponse<Http::STATUS_OK, TalkRoom, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, array{error: 'breakout-room'|'type'|'value'}, array{}>
 	 *
 	 * 200: Message expiration time updated successfully
 	 * 400: Updating message expiration time is not possible
@ -2448,7 +2451,7 @@ class RoomController extends AEnvironmentAwareController {
 			return new DataResponse(['error' => $e->getReason()], Http::STATUS_BAD_REQUEST);
 		}

-		return new DataResponse();
+		return new DataResponse($this->formatRoom($this->room, $this->participant));
 	}

 	/**
@ -2499,7 +2502,7 @@ class RoomController extends AEnvironmentAwareController {
 	 * See "Capability handling in federated conversations" in https://github.com/nextcloud/spreed/issues/10680
 	 * to learn which capabilities should be considered from the local server or from the remote server.
 	 *
-	 * @return DataResponse<Http::STATUS_OK, TalkCapabilities|array<empty>, array{X-Nextcloud-Talk-Hash?: string, X-Nextcloud-Talk-Proxy-Hash?: string}>
+	 * @return DataResponse<Http::STATUS_OK, TalkCapabilities|\stdClass, array{X-Nextcloud-Talk-Hash?: string, X-Nextcloud-Talk-Proxy-Hash?: string}>
 	 *
 	 * 200: Get capabilities successfully
 	 */
@ -2538,9 +2541,12 @@ class RoomController extends AEnvironmentAwareController {
 			if ($response->getHeaders()['X-Nextcloud-Talk-Hash']) {
 				$headers['X-Nextcloud-Talk-Proxy-Hash'] = $response->getHeaders()['X-Nextcloud-Talk-Hash'];
 			}
+
+			/** @var TalkCapabilities|\stdClass $data */
+			$data = !empty($data) ? $data : new \stdClass();
 		} else {
 			$capabilities = $this->capabilities->getCapabilities();
-			$data = $capabilities['spreed'] ?? [];
+			$data = $capabilities['spreed'] ?? new \stdClass();
 			$headers['X-Nextcloud-Talk-Hash'] = sha1(json_encode($capabilities));
 		}

--- a/lib/Exceptions/FederationRestrictionException.php
+++ b/lib/Exceptions/FederationRestrictionException.php
@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+
+namespace OCA\Talk\Exceptions;
+
+class FederationRestrictionException extends \InvalidArgumentException {
+	public const REASON_CLOUD_ID = 'cloud-id';
+	public const REASON_FEDERATION = 'federation';
+	public const REASON_OUTGOING = 'outgoing';
+	public const REASON_TRUSTED_SERVERS = 'trusted-servers';
+
+	/**
+	 * @param self::REASON_* $reason
+	 */
+	public function __construct(
+		protected readonly string $reason,
+	) {
+		parent::__construct($this->reason);
+	}
+
+	/**
+	 * @return self::REASON_*
+	 */
+	public function getReason(): string {
+		return $this->reason;
+	}
+}
--- a/lib/Exceptions/ParticipantProperty/PermissionsException.php
+++ b/lib/Exceptions/ParticipantProperty/PermissionsException.php
@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Talk\Exceptions\ParticipantProperty;
+
+class PermissionsException extends \InvalidArgumentException {
+	public const REASON_METHOD = 'method';
+	public const REASON_MODERATOR = 'moderator';
+	public const REASON_ROOM_TYPE = 'room-type';
+	public const REASON_TYPE = 'type';
+	public const REASON_VALUE = 'value';
+
+	/**
+	 * @param self::REASON_* $reason
+	 */
+	public function __construct(
+		protected string $reason,
+	) {
+		parent::__construct($reason);
+	}
+
+	/**
+	 * @return self::REASON_*
+	 */
+	public function getReason(): string {
+		return $this->reason;
+	}
+}
--- a/lib/Federation/FederationManager.php
+++ b/lib/Federation/FederationManager.php
@ -10,6 +10,7 @@ namespace OCA\Talk\Federation;

 use OCA\Talk\AppInfo\Application;
 use OCA\Talk\Exceptions\CannotReachRemoteException;
+use OCA\Talk\Exceptions\FederationRestrictionException;
 use OCA\Talk\Exceptions\ParticipantNotFoundException;
 use OCA\Talk\Exceptions\RoomNotFoundException;
 use OCA\Talk\Exceptions\UnauthorizedException;
@ -64,7 +65,7 @@ class FederationManager {
 	/**
 	 * Check if $sharedBy is allowed to invite $shareWith
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws FederationRestrictionException
 	 */
 	public function isAllowedToInvite(
 		IUser $user,
--- a/lib/Federation/Proxy/TalkV1/Controller/RoomController.php
+++ b/lib/Federation/Proxy/TalkV1/Controller/RoomController.php
@ -33,7 +33,7 @@ class RoomController {
 	/**
 	 * @see \OCA\Talk\Controller\RoomController::getParticipants()
 	 *
-	 * @return DataResponse<Http::STATUS_OK, TalkParticipant[], array{X-Nextcloud-Has-User-Statuses?: bool}>
+	 * @return DataResponse<Http::STATUS_OK, list<TalkParticipant>, array{X-Nextcloud-Has-User-Statuses?: bool}>
 	 * @throws CannotReachRemoteException
 	 *
 	 * 200: Participants returned
@ -46,10 +46,10 @@ class RoomController {
 			$room->getRemoteServer() . '/ocs/v2.php/apps/spreed/api/v4/room/' . $room->getRemoteToken() . '/participants',
 		);

-		/** @var TalkParticipant[] $data */
+		/** @var list<TalkParticipant> $data */
 		$data = $this->proxy->getOCSData($proxy);

-		/** @var TalkParticipant[] $data */
+		/** @var list<TalkParticipant> $data */
 		$data = $this->userConverter->convertAttendees($room, $data, 'actorType', 'actorId', 'displayName');
 		$headers = [];
 		if ($proxy->getHeader('X-Nextcloud-Has-User-Statuses')) {
@ -157,4 +157,13 @@ class RoomController {

 		return new DataResponse($data, Http::STATUS_OK, $headers);
 	}
+
+	/**
+	 * @return array<string, mixed>|\stdClass
+	 */
+	protected function emptyArray(): array|\stdClass {
+		// Cheating here to make sure the array is always a
+		// JSON object on the API, even when there is no entry at all.
+		return new \stdClass();
+	}
 }
--- a/lib/Federation/RestrictionValidator.php
+++ b/lib/Federation/RestrictionValidator.php
@ -11,6 +11,7 @@ namespace OCA\Talk\Federation;
 use OCA\FederatedFileSharing\AddressHandler;
 use OCA\Federation\TrustedServers;
 use OCA\Talk\Config;
+use OCA\Talk\Exceptions\FederationRestrictionException;
 use OCP\App\IAppManager;
 use OCP\AppFramework\Services\IAppConfig;
 use OCP\Federation\ICloudId;
@ -31,7 +32,7 @@ class RestrictionValidator {
 	/**
 	 * Check if $sharedBy is allowed to invite $shareWith
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws FederationRestrictionException
 	 */
 	public function isAllowedToInvite(
 		IUser $user,
@ -39,23 +40,23 @@ class RestrictionValidator {
 	): void {
 		if (!($cloudIdToInvite->getUser() && $cloudIdToInvite->getRemote())) {
 			$this->logger->debug('Could not share conversation as the recipient is invalid: ' . $cloudIdToInvite->getId());
-			throw new \InvalidArgumentException('cloudId');
+			throw new FederationRestrictionException(FederationRestrictionException::REASON_CLOUD_ID);
 		}

 		if (!$this->appConfig->getAppValueBool('federation_outgoing_enabled', true)) {
 			$this->logger->debug('Could not share conversation as outgoing federation is disabled');
-			throw new \InvalidArgumentException('outgoing');
+			throw new FederationRestrictionException(FederationRestrictionException::REASON_OUTGOING);
 		}

 		if (!$this->talkConfig->isFederationEnabledForUserId($user)) {
 			$this->logger->debug('Talk federation not allowed for user ' . $user->getUID());
-			throw new \InvalidArgumentException('federation');
+			throw new FederationRestrictionException(FederationRestrictionException::REASON_FEDERATION);
 		}

 		if ($this->appConfig->getAppValueBool('federation_only_trusted_servers')) {
 			if (!$this->appManager->isEnabledForUser('federation')) {
 				$this->logger->error('Federation is limited to trusted servers but the "federation" app is disabled');
-				throw new \InvalidArgumentException('trusted_servers');
+				throw new FederationRestrictionException(FederationRestrictionException::REASON_TRUSTED_SERVERS);
 			}

 			$trustedServers = Server::get(TrustedServers::class);
@ -65,7 +66,7 @@ class RestrictionValidator {
 					'Tried to send Talk federation invite to untrusted server {serverUrl}',
 					['serverUrl' => $serverUrl]
 				);
-				throw new \InvalidArgumentException('trusted_servers');
+				throw new FederationRestrictionException(FederationRestrictionException::REASON_TRUSTED_SERVERS);
 			}
 		}
 	}
--- a/lib/Service/ParticipantService.php
+++ b/lib/Service/ParticipantService.php
@ -38,9 +38,9 @@ use OCA\Talk\Events\SystemMessagesMultipleSentEvent;
 use OCA\Talk\Events\UserJoinedRoomEvent;
 use OCA\Talk\Exceptions\CannotReachRemoteException;
 use OCA\Talk\Exceptions\DialOutFailedException;
-use OCA\Talk\Exceptions\ForbiddenException;
 use OCA\Talk\Exceptions\InvalidPasswordException;
 use OCA\Talk\Exceptions\ParticipantNotFoundException;
+use OCA\Talk\Exceptions\ParticipantProperty\PermissionsException;
 use OCA\Talk\Exceptions\UnauthorizedException;
 use OCA\Talk\Federation\BackendNotifier;
 use OCA\Talk\Federation\FederationManager;
@ -183,23 +183,26 @@ class ParticipantService {
 	}

 	/**
-	 * @throws Exception
-	 * @throws ForbiddenException
+	 * @throws PermissionsException
 	 */
-	public function updatePermissions(Room $room, Participant $participant, string $method, int $newPermissions): bool {
+	public function updatePermissions(Room $room, Participant $participant, string $method, int $newPermissions): void {
 		if ($room->getType() === Room::TYPE_ONE_TO_ONE || $room->getType() === Room::TYPE_ONE_TO_ONE_FORMER) {
-			return false;
+			throw new PermissionsException(PermissionsException::REASON_ROOM_TYPE);
 		}

 		if ($participant->hasModeratorPermissions()) {
-			throw new ForbiddenException();
+			throw new PermissionsException(PermissionsException::REASON_MODERATOR);
 		}

 		$attendee = $participant->getAttendee();

 		if ($attendee->getActorType() === Attendee::ACTOR_GROUPS || $attendee->getActorType() === Attendee::ACTOR_CIRCLES) {
 			// Can not set publishing permissions for those actor types
-			return false;
+			throw new PermissionsException(PermissionsException::REASON_TYPE);
+		}
+
+		if ($newPermissions < Attendee::PERMISSIONS_DEFAULT || $newPermissions > Attendee::PERMISSIONS_MAX_CUSTOM) {
+			throw new PermissionsException(PermissionsException::REASON_VALUE);
 		}

 		$oldPermissions = $participant->getPermissions();
@ -213,7 +216,7 @@ class ParticipantService {
 		} elseif ($method === Attendee::PERMISSIONS_MODIFY_REMOVE) {
 			$newPermissions = $oldPermissions & ~$newPermissions;
 		} else {
-			return false;
+			throw new PermissionsException(PermissionsException::REASON_METHOD);
 		}

 		$event = new BeforeParticipantModifiedEvent($room, $participant, AParticipantModifiedEvent::PROPERTY_PERMISSIONS, $newPermissions, $oldPermissions);
@ -228,8 +231,6 @@ class ParticipantService {

 		$event = new ParticipantModifiedEvent($room, $participant, AParticipantModifiedEvent::PROPERTY_PERMISSIONS, $newPermissions, $oldPermissions);
 		$this->dispatcher->dispatchTyped($event);
-
-		return true;
 	}

 	public function updateAllPermissions(Room $room, string $method, int $newState): void {
@ -271,7 +272,7 @@ class ParticipantService {
 			Participant::NOTIFY_MENTION,
 			Participant::NOTIFY_NEVER
 		], true)) {
-			throw new \InvalidArgumentException('Invalid notification level');
+			throw new \InvalidArgumentException('level');
 		}

 		$attendee = $participant->getAttendee();
@ -283,13 +284,14 @@ class ParticipantService {
 	/**
 	 * @param Participant $participant
 	 * @param int $level
+	 * @throws \InvalidArgumentException
 	 */
 	public function updateNotificationCalls(Participant $participant, int $level): void {
 		if (!\in_array($level, [
 			Participant::NOTIFY_CALLS_OFF,
 			Participant::NOTIFY_CALLS_ON,
 		], true)) {
-			throw new \InvalidArgumentException('Invalid notification level');
+			throw new \InvalidArgumentException('level');
 		}

 		$attendee = $participant->getAttendee();
--- a/lib/Service/RoomService.php
+++ b/lib/Service/RoomService.php
@ -93,7 +93,7 @@ class RoomService {
 	 */
 	public function createOneToOneConversation(IUser $actor, IUser $targetUser): Room {
 		if ($actor->getUID() === $targetUser->getUID()) {
-			throw new InvalidArgumentException('invalid_invitee');
+			throw new InvalidArgumentException('invite');
 		}

 		try {
--- a/tests/php/Service/RoomServiceTest.php
+++ b/tests/php/Service/RoomServiceTest.php
@ -84,7 +84,7 @@ class RoomServiceTest extends TestCase {
 			->willReturn('uid');

 		$this->expectException(InvalidArgumentException::class);
-		$this->expectExceptionMessage('invalid_invitee');
+		$this->expectExceptionMessage('invite');
 		$this->service->createOneToOneConversation($user, $user);
 	}