diff --git a/composer.json b/composer.json
index 3123b43..80cd8fc 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,8 @@
     "require-dev": {
         "phpunit/phpunit": "^8",
         "friendsofphp/php-cs-fixer": "^2.16",
-        "nextcloud/coding-standard": "^0.3.0"
+        "nextcloud/coding-standard": "^0.3.0",
+        "phpstan/phpstan": "^0.12.29"
     },
     "config": {
         "optimize-autoloader": true,
diff --git a/composer.lock b/composer.lock
index 1175167..b803d40 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "a5f7d2fab7db00ef99eb9468c2fa9a0a",
+    "content-hash": "6889c8d8926c05b33570a53abc170e3f",
     "packages": [
         {
             "name": "littleredbutton/bigbluebutton-api-php",
@@ -1026,6 +1026,62 @@
             ],
             "time": "2020-03-05T15:02:03+00:00"
         },
+        {
+            "name": "phpstan/phpstan",
+            "version": "0.12.29",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpstan/phpstan.git",
+                "reference": "9771daaf6b95c6313b908d0bcdee0afcd51f838a"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/9771daaf6b95c6313b908d0bcdee0afcd51f838a",
+                "reference": "9771daaf6b95c6313b908d0bcdee0afcd51f838a",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.1"
+            },
+            "conflict": {
+                "phpstan/phpstan-shim": "*"
+            },
+            "bin": [
+                "phpstan",
+                "phpstan.phar"
+            ],
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "0.12-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "PHPStan - PHP Static Analysis Tool",
+            "funding": [
+                {
+                    "url": "https://github.com/ondrejmirtes",
+                    "type": "github"
+                },
+                {
+                    "url": "https://www.patreon.com/phpstan",
+                    "type": "patreon"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/phpstan/phpstan",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2020-06-14T14:10:59+00:00"
+        },
         {
             "name": "phpunit/php-code-coverage",
             "version": "7.0.10",
diff --git a/lib/BigBlueButton/API.php b/lib/BigBlueButton/API.php
index 7643f7d..861d0fe 100644
--- a/lib/BigBlueButton/API.php
+++ b/lib/BigBlueButton/API.php
@@ -24,7 +24,7 @@ class API {
 	/** @var Permission */
 	private $permission;
 
-	/** @var BigBlueButton */
+	/** @var BigBlueButton|null */
 	private $server;
 
 	public function __construct(
diff --git a/lib/Controller/JoinController.php b/lib/Controller/JoinController.php
index c025427..23708fb 100644
--- a/lib/Controller/JoinController.php
+++ b/lib/Controller/JoinController.php
@@ -10,7 +10,6 @@ use OCA\BigBlueButton\NotFoundException;
 use OCA\BigBlueButton\Permission;
 use OCP\AppFramework\Http\RedirectResponse;
 use OCP\IRequest;
-use OCP\ISession;
 use OCP\IURLGenerator;
 use OCP\IUserSession;
 use OCP\IConfig;
@@ -22,7 +21,7 @@ class JoinController extends Controller {
 	/** @var string */
 	protected $token;
 
-	/** @var Room */
+	/** @var Room|null */
 	protected $room;
 
 	/** @var RoomService */
@@ -46,7 +45,6 @@ class JoinController extends Controller {
 	public function __construct(
 		string $appName,
 		IRequest $request,
-		ISession $session,
 		RoomService $service,
 		IURLGenerator $urlGenerator,
 		IUserSession $userSession,
@@ -54,7 +52,7 @@ class JoinController extends Controller {
 		API $api,
 		Permission $permission
 	) {
-		parent::__construct($appName, $request, $session);
+		parent::__construct($appName, $request);
 
 		$this->service = $service;
 		$this->urlGenerator = $urlGenerator;
diff --git a/lib/Controller/ServerController.php b/lib/Controller/ServerController.php
index 6e2d2bb..f9d9540 100644
--- a/lib/Controller/ServerController.php
+++ b/lib/Controller/ServerController.php
@@ -80,7 +80,7 @@ class ServerController extends Controller {
 		return new DataResponse($success);
 	}
 
-	public function check(string $url, string $secret) {
+	public function check(?string $url, ?string $secret) {
 		if ($url === null || empty($url) || $secret === null || empty($secret)) {
 			return new DataResponse(false);
 		}
@@ -88,7 +88,7 @@ class ServerController extends Controller {
 		return new DataResponse($this->server->check($url, $secret));
 	}
 
-	public function version(string $url) {
+	public function version(?string $url) {
 		if ($url === null || empty($url)) {
 			return new DataResponse(false, Http::STATUS_NOT_FOUND);
 		}
diff --git a/lib/Db/Room.php b/lib/Db/Room.php
index a9609b2..31c4f82 100644
--- a/lib/Db/Room.php
+++ b/lib/Db/Room.php
@@ -6,6 +6,30 @@ use JsonSerializable;
 
 use OCP\AppFramework\Db\Entity;
 
+/**
+ * @method string getUid()
+ * @method string getName()
+ * @method string getAttendeePassword()
+ * @method string getModeratorPassword()
+ * @method string getWelcome()
+ * @method int getMaxParticipants()
+ * @method bool getRecord()
+ * @method string getUserId()
+ * @method string getAccess()
+ * @method string getPassword()
+ * @method bool getEveryoneIsModerator()
+ * @method void setUid(string $uid)
+ * @method void setName(string $name)
+ * @method void setAttendeePassword(string $pw)
+ * @method void setModeratorPassword(string $pw)
+ * @method void setWelcome(string $welcome)
+ * @method void setMaxParticipants(int $max)
+ * @method void setRecord(bool $record)
+ * @method void setUserId(string $userId)
+ * @method void setAccess(string $access)
+ * @method void setPassword(string $pw)
+ * @method void setEveryoneIsModerator(bool $everyone)
+ */
 class Room extends Entity implements JsonSerializable {
 	public const ACCESS_PUBLIC = 'public';
 	public const ACCESS_PASSWORD = 'password';
diff --git a/lib/Db/RoomMapper.php b/lib/Db/RoomMapper.php
index a9fdfab..a449d36 100644
--- a/lib/Db/RoomMapper.php
+++ b/lib/Db/RoomMapper.php
@@ -3,7 +3,6 @@
 namespace OCA\BigBlueButton\Db;
 
 use OCP\AppFramework\Db\DoesNotExistException;
-use OCP\AppFramework\Db\Entity;
 use OCP\AppFramework\Db\QBMapper;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
@@ -14,9 +13,6 @@ class RoomMapper extends QBMapper {
 	}
 
 	/**
-	 * @param int $id
-	 * @param string $userId
-	 * @return Entity|Room
 	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
 	 * @throws DoesNotExistException
 	 */
@@ -26,12 +22,12 @@ class RoomMapper extends QBMapper {
 		$qb->select('*')
 			->from($this->tableName)
 			->where($qb->expr()->eq('id', $qb->createNamedParameter($id, IQueryBuilder::PARAM_INT)));
+
+		/** @var Room */
 		return $this->findEntity($qb);
 	}
 
 	/**
-	 * @param string $uid
-	 * @return Entity|Room
 	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
 	 * @throws DoesNotExistException
 	 */
@@ -41,13 +37,13 @@ class RoomMapper extends QBMapper {
 		$qb->select('*')
 			->from($this->tableName)
 			->where($qb->expr()->eq('uid', $qb->createNamedParameter($uid)));
+
+		/** @var Room */
 		return $this->findEntity($qb);
 	}
 
 	/**
-	 * @param int $userId
-	 * @param array $groupIds
-	 * @return array
+	 * @return array<Room>
 	 */
 	public function findAll(string $userId, array $groupIds): array {
 		/* @var $qb IQueryBuilder */
@@ -71,6 +67,8 @@ class RoomMapper extends QBMapper {
 				)
 			)
 			->groupBy('r.id');
+
+		/** @var array<Room> */
 		return $this->findEntities($qb);
 	}
 }
diff --git a/lib/Db/RoomShare.php b/lib/Db/RoomShare.php
index f7306c8..c6585eb 100644
--- a/lib/Db/RoomShare.php
+++ b/lib/Db/RoomShare.php
@@ -6,6 +6,19 @@ use JsonSerializable;
 
 use OCP\AppFramework\Db\Entity;
 
+/**
+ * @method int getRoomId()
+ * @method int getShareType()
+ * @method string getShareWith()
+ * @method string|null getShareWithDisplayName()
+ * @method int getPermission()
+ * @method void setShareWithDisplayName(string $displayName)
+ * @method void setRoomId(int $id)
+ * @method void setShareType(int $type)
+ * @method void setShareWith(string $with)
+ * @method void setShareWithDisplayName(string $displayName)
+ * @method void setPermission(int $permission)
+ */
 class RoomShare extends Entity implements JsonSerializable {
 	public const PERMISSION_ADMIN = 0;
 	public const PERMISSION_MODERATOR = 1;
diff --git a/lib/Db/RoomShareMapper.php b/lib/Db/RoomShareMapper.php
index 82ffbcb..240b53c 100644
--- a/lib/Db/RoomShareMapper.php
+++ b/lib/Db/RoomShareMapper.php
@@ -3,7 +3,6 @@
 namespace OCA\BigBlueButton\Db;
 
 use OCP\AppFramework\Db\DoesNotExistException;
-use OCP\AppFramework\Db\Entity;
 use OCP\AppFramework\Db\QBMapper;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
@@ -14,8 +13,6 @@ class RoomShareMapper extends QBMapper {
 	}
 
 	/**
-	 * @param int $id
-	 * @return Entity|RoomShare
 	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
 	 * @throws DoesNotExistException
 	 */
@@ -25,9 +22,15 @@ class RoomShareMapper extends QBMapper {
 		$qb->select('*')
 			->from('bbb_room_shares')
 			->where($qb->expr()->eq('id', $qb->createNamedParameter($id, IQueryBuilder::PARAM_INT)));
+
+		/** @var RoomShare */
 		return $this->findEntity($qb);
 	}
 
+	/**
+	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
+	 * @throws DoesNotExistException
+	 */
 	public function findByRoomAndEntity(int $roomId, string $shareWith, int $shareType): RoomShare {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
@@ -37,15 +40,21 @@ class RoomShareMapper extends QBMapper {
 			->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($shareWith)))
 			->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter($shareType, IQueryBuilder::PARAM_INT)));
 
+		/** @var RoomShare */
 		return $this->findEntity($qb);
 	}
 
+	/**
+	 * @return array<RoomShare>
+	 */
 	public function findAll(int $roomId): array {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
 			->from('bbb_room_shares')
 			->where($qb->expr()->eq('room_id', $qb->createNamedParameter($roomId, IQueryBuilder::PARAM_INT)));
+
+		/** @var array<RoomShare> */
 		return $this->findEntities($qb);
 	}
 }
diff --git a/lib/Service/RoomService.php b/lib/Service/RoomService.php
index 68d2217..f53404b 100644
--- a/lib/Service/RoomService.php
+++ b/lib/Service/RoomService.php
@@ -32,6 +32,9 @@ class RoomService {
 		}
 	}
 
+	/**
+	 * @throws RoomNotFound
+	 */
 	public function find($id): Room {
 		try {
 			return $this->mapper->find($id);
diff --git a/tests/Unit/Controller/JoinControllerTest.php b/tests/Unit/Controller/JoinControllerTest.php
index 630815d..6199a56 100644
--- a/tests/Unit/Controller/JoinControllerTest.php
+++ b/tests/Unit/Controller/JoinControllerTest.php
@@ -5,7 +5,6 @@ namespace OCA\BigBlueButton\Tests\Controller;
 use PHPUnit\Framework\TestCase;
 use OCP\AppFramework\Http\RedirectResponse;
 use OCP\IURLGenerator;
-use OCP\ISession;
 use OCP\IUserSession;
 use OCP\IConfig;
 use OCP\IRequest;
@@ -34,7 +33,6 @@ class JoinControllerTest extends TestCase {
 		parent::setUp();
 
 		$this->request = $this->createMock(IRequest::class);
-		$this->session = $this->createMock(ISession::class);
 		$this->service = $this->createMock(RoomService::class);
 		$this->userSession = $this->createMock(IUserSession::class);
 		$this->config = $this->createMock(IConfig::class);
@@ -45,7 +43,6 @@ class JoinControllerTest extends TestCase {
 		$this->controller = new JoinController(
 			'bbb',
 			$this->request,
-			$this->session,
 			$this->service,
 			$this->urlGenerator,
 			$this->userSession,