diff --git a/tests/unit/lib/Controller/AdminControllerTest.php b/tests/unit/lib/Controller/AdminControllerTest.php
index f67b1d1c2..6affbeedb 100644
--- a/tests/unit/lib/Controller/AdminControllerTest.php
+++ b/tests/unit/lib/Controller/AdminControllerTest.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * SPDX-FileCopyrightText: 2022 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 
@@ -9,110 +9,398 @@
 
 use OCA\Circles\AppInfo\Application;
 use OCA\Circles\Controller\AdminController;
+use OCA\Circles\Exceptions\CircleNotFoundException;
+use OCA\Circles\Exceptions\MemberNotFoundException;
 use OCA\Circles\Model\Circle;
-use OCA\Circles\Model\Probes\BasicProbe;
-use OCA\Circles\Model\Probes\CircleProbe;
+use OCA\Circles\Model\Member;
 use OCA\Circles\Service\CircleService;
 use OCA\Circles\Service\ConfigService;
 use OCA\Circles\Service\FederatedUserService;
 use OCA\Circles\Service\MemberService;
 use OCA\Circles\Service\MembershipService;
 use OCA\Circles\Service\SearchService;
-use OCA\Circles\Tools\Traits\TDeserialize;
-use OCP\AppFramework\Http\DataResponse;
-use OCP\AppFramework\OCS\OCSException;
 use OCP\IRequest;
-use OCP\IUser;
+use OCP\IUserManager;
 use OCP\IUserSession;
-use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\Attributes\Group;
+use Psr\Container\ContainerInterface;
 use Test\TestCase;
 
-/**
- * @group DB
- */
+#[Group('DB')]
 class AdminControllerTest extends TestCase {
-	use TDeserialize;
+	// suffix user ids with hash to avoid collision with existing users
+	private const TEST_USER_1 = 'circles-test-user-98cb5bac';
+	private const TEST_USER_2 = 'circles-test-user-bc412b0c';
 
-	/** @var IRequest|MockObject */
-	private $request;
+	private ContainerInterface $container;
+	private Application $app;
+	private AdminController $adminController;
+	private IUserManager $userManager;
+	private array $circlesToCleanup = [];
+	private static array $usersToCleanup = [];
 
-	/** @var IUserSession|MockObject */
-	private $userSession;
+	public static function setUpBeforeClass(): void {
+		parent::setUpBeforeClass();
 
-	/** @var FederatedUserService|MockObject */
-	private $federatedUserService;
+		$app = new Application();
+		$userManager = $app->getContainer()->get(IUserManager::class);
 
-	/** @var CircleService|MockObject */
-	private $circleService;
+		foreach ([self::TEST_USER_1, self::TEST_USER_2] as $userId) {
+			$user = $userManager->get($userId);
+			if ($user === null) {
+				$userManager->createUser($userId, 'test-pwd');
+				self::$usersToCleanup[] = $userId;
+			}
+		}
+	}
 
-	/** @var MemberService|MockObject */
-	private $memberService;
+	public function setUp(): void {
+		parent::setUp();
 
-	/** @var MembershipService|MockObject */
-	private $membershipService;
+		$this->app = new Application();
+		$this->container = $this->app->getContainer();
+		$this->userManager = $this->container->get(IUserManager::class);
 
-	/** @var SearchService|MockObject */
-	private $searchService;
+		$userSession = $this->container->get(IUserSession::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
 
-	/** @var ConfigService|MockObject */
-	private $configService;
+		$user1 = $this->userManager->get(self::TEST_USER_1);
+		$userSession->setUser($user1);
+		$federatedUserService->setLocalCurrentUser($user1);
 
-	/** @var AdminController */
-	private $adminController;
+		$this->adminController = new AdminController(
+			Application::APP_ID,
+			$this->container->get(IRequest::class),
+			$userSession,
+			$federatedUserService,
+			$this->container->get(CircleService::class),
+			$this->container->get(MemberService::class),
+			$this->container->get(MembershipService::class),
+			$this->container->get(SearchService::class),
+			$this->container->get(ConfigService::class),
+		);
+	}
 
-	public function setUp(): void {
-		parent::setUp();
-		$this->request = $this->createMock(IRequest::class);
-		$this->userSession = $this->createMock(IUserSession::class);
-		$this->federatedUserService = $this->createMock(FederatedUserService::class);
-		$this->circleService = $this->createMock(CircleService::class);
-		$this->memberService = $this->createMock(MemberService::class);
-		$this->membershipService = $this->createMock(MembershipService::class);
-		$this->searchService = $this->createMock(SearchService::class);
-		$this->configService = $this->createMock(ConfigService::class);
-		$this->configService->expects($this->any())->method('getAppValueBool')->with(ConfigService::FRONTEND_ENABLED)->willReturn(true);
-		$this->adminController = new AdminController(Application::APP_ID, $this->request, $this->userSession, $this->federatedUserService, $this->circleService, $this->memberService, $this->membershipService, $this->searchService, $this->configService);
-	}
-
-	/**
-	 * @dataProvider dataForCirclesList
-	 *
-	 * @param int $limit
-	 * @param int $offset
-	 * @return void
-	 * @throws OCSException
-	 */
-	public function testCirclesList(int $limit, int $offset): void {
-		$user = $this->createMock(IUser::class);
-		$user->expects($this->once())->method('getUID')->with()->willReturn('an-user-id');
-		$this->userSession->expects($this->any())->method('getUser')->with()->willReturn($user);
-
-		$probe = new CircleProbe();
-		$probe->filterHiddenCircles()
-			->filterBackendCircles()
-			->addDetail(BasicProbe::DETAILS_POPULATION)
-			->setItemsOffset($offset)
-			->setItemsLimit($limit);
-		$circle1 = new Circle();
-		$circle1->setName('Circle One');
-		$circle1->setSingleId('CircleOne');
-		$circle2 = new Circle();
-		$circle2->setName('Circle Two');
-		$circle2->setSingleId('CircleTwo');
-		$circle3 = new Circle();
-		$circle3->setName('Circle Three');
-		$circle3->setSingleId('CircleThree');
-		$circles = [$circle1, $circle2, $circle3];
-		$selectedCircles = array_slice($circles, $offset, $limit > 0 ? $limit : null);
-		$this->circleService->expects($this->once())->method('getCircles')->with($probe)->willReturn($selectedCircles);
-		$response = new DataResponse($this->serializeArray($selectedCircles));
-		$this->assertEquals($response, $this->adminController->circles('an-user-id', $limit, $offset));
-	}
-
-	public static function dataForCirclesList(): array {
-		return [
-			[-1, 0],
-			[1, 1]
+	public static function tearDownAfterClass(): void {
+		parent::tearDownAfterClass();
+
+		$app = new Application();
+		$userManager = $app->getContainer()->get(IUserManager::class);
+
+		foreach (self::$usersToCleanup as $userId) {
+			$userManager->get($userId)?->delete();
+		}
+	}
+
+	protected function tearDown(): void {
+		parent::tearDown();
+
+		$circleService = $this->container->get(CircleService::class);
+
+		foreach ($this->circlesToCleanup as $circleId) {
+			try {
+				$circleService->destroy($circleId);
+			} catch (\Throwable) {
+				// continue cleanup
+			}
+		}
+	}
+
+	public function testCreate(): void {
+		$result = $this->adminController->create(self::TEST_USER_1, 'test-circle')->getData();
+		$this->circlesToCleanup[] = $result['id'];
+
+		$this->assertSame($result['name'], 'test-circle');
+		$this->assertSame($result['population'], 0);
+		$this->assertSame($result['config'], 0);
+		$this->assertSame($result['initiator']['userId'], self::TEST_USER_1);
+		$this->assertSame($result['initiator']['level'], Member::LEVEL_OWNER);
+		$this->assertSame($result['owner']['userId'], self::TEST_USER_1);
+	}
+
+	public function testDestroy(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+
+		$this->adminController->destroy(self::TEST_USER_1, $circleData['id']);
+
+		$this->expectException(CircleNotFoundException::class);
+
+		$circleService->getCircle($circleData['id']);
+	}
+
+	public function testMemberAdd(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$result = $this->adminController->memberAdd(self::TEST_USER_1, $circleData['id'], self::TEST_USER_2, Member::TYPE_USER)->getData();
+
+		$this->assertSame($result['circleId'], $circleData['id']);
+		$this->assertSame($result['userId'], self::TEST_USER_2);
+		$this->assertSame($result['level'], Member::LEVEL_MEMBER);
+	}
+
+	public function testMemberLevel(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
+		$memberService = $this->container->get(MemberService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$user2 = $federatedUserService->generateFederatedUser(self::TEST_USER_2, Member::TYPE_USER);
+		$memberData = $memberService->addMember($circleData['id'], $user2);
+
+		$result = $this->adminController->memberLevel(self::TEST_USER_1, $circleData['id'], $memberData['id'], Member::LEVEL_MODERATOR)->getData();
+
+		$this->assertSame($result['circleId'], $circleData['id']);
+		$this->assertSame($result['userId'], self::TEST_USER_2);
+		$this->assertSame($result['level'], Member::LEVEL_MODERATOR);
+	}
+
+	public function testCircles(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		/**
+		 * count before, as circles not created by this test may be returned
+		 * by the controller (e.g. "visible to everyone" circles)
+		 */
+		$countBefore = count($this->adminController->circles(self::TEST_USER_1)->getData());
+
+		$circleData = $circleService->create('test-circle');
+		$circleData2 = $circleService->create('test-circle-2');
+		$circleData3 = $circleService->create('test-circle-3');
+		$this->circlesToCleanup[] = $circleData['id'];
+		$this->circlesToCleanup[] = $circleData2['id'];
+		$this->circlesToCleanup[] = $circleData3['id'];
+
+		$circleDataMap = [
+			$circleData['id'] => $circleData,
+			$circleData2['id'] => $circleData2,
+			$circleData3['id'] => $circleData3,
 		];
+
+		$result = $this->adminController->circles(self::TEST_USER_1)->getData();
+
+		$this->assertCount($countBefore + 3, $result);
+
+		foreach ($result as $circle) {
+			// skip circles that were not created by this test
+			if (!isset($circleDataMap[$circle['id']])) {
+				continue;
+			}
+			$this->assertSame($circle['id'], $circleDataMap[$circle['id']]['id']);
+			$this->assertSame($circle['name'], $circleDataMap[$circle['id']]['name']);
+			$this->assertSame($circle['config'], $circleDataMap[$circle['id']]['config']);
+			$this->assertSame($circle['initiator']['userId'], $circleDataMap[$circle['id']]['initiator']['userId']);
+			$this->assertSame($circle['initiator']['level'], $circleDataMap[$circle['id']]['initiator']['level']);
+			$this->assertSame($circle['owner']['userId'], $circleDataMap[$circle['id']]['owner']['userId']);
+		}
+	}
+
+	public function testCircleDetails(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$result = $this->adminController->circleDetails(self::TEST_USER_1, $circleData['id'])->getData();
+
+		$this->assertSame($result['id'], $circleData['id']);
+		$this->assertSame($result['name'], $circleData['name']);
+		$this->assertSame($result['config'], $circleData['config']);
+		$this->assertSame($result['initiator']['userId'], $circleData['initiator']['userId']);
+		$this->assertSame($result['initiator']['level'], $circleData['initiator']['level']);
+		$this->assertSame($result['owner']['userId'], $circleData['owner']['userId']);
+	}
+
+	public function testCircleJoin(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$memberService = $this->container->get(MemberService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		// circle is visible to everyone and anyone can join
+		$circleConfig = Circle::CFG_VISIBLE + Circle::CFG_OPEN;
+		$circleService->updateConfig($circleData['id'], $circleConfig);
+
+		$result = $this->adminController->circleJoin(self::TEST_USER_2, $circleData['id'])->getData();
+
+		/** @var Member $member */
+		$member = $memberService->getMemberById($result['id'], $result['circleId']);
+
+		$this->assertSame($result['id'], $member->getId());
+		$this->assertSame($result['circleId'], $circleData['id']);
+		$this->assertSame($result['userId'], self::TEST_USER_2);
+		$this->assertSame($result['userType'], Member::TYPE_USER);
+		$this->assertSame($result['level'], Member::LEVEL_MEMBER);
+	}
+
+	public function testCircleLeave(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
+		$memberService = $this->container->get(MemberService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		// circle is visible to everyone and anyone can join
+		$circleConfig = Circle::CFG_VISIBLE + Circle::CFG_OPEN;
+		$circleService->updateConfig($circleData['id'], $circleConfig);
+
+		$user2 = $this->userManager->get(self::TEST_USER_2);
+
+		$federatedUserService->setLocalCurrentUser($user2);
+		$memberData = $circleService->circleJoin($circleData['id']);
+
+		$this->adminController->circleLeave(self::TEST_USER_2, $circleData['id'])->getData();
+
+		$this->expectException(MemberNotFoundException::class);
+
+		$memberService->getMemberById($memberData['id'], $circleData['id']);
+	}
+
+	public function testMemberConfirm(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		// circle is visible to everyone but requires approval to join
+		$circleConfig = Circle::CFG_VISIBLE + Circle::CFG_OPEN + Circle::CFG_REQUEST;
+		$circleService->updateConfig($circleData['id'], $circleConfig);
+
+		$user1 = $this->userManager->get(self::TEST_USER_1);
+		$user2 = $this->userManager->get(self::TEST_USER_2);
+
+		$federatedUserService->setLocalCurrentUser($user2);
+		$memberData = $circleService->circleJoin($circleData['id']);
+
+		$federatedUserService->setLocalCurrentUser($user1);
+
+		// as TEST_USER_1, allow TEST_USER_2 to be a member of the team
+		$result = $this->adminController->memberConfirm(self::TEST_USER_1, $circleData['id'], $memberData['id'])->getData();
+
+		$this->assertSame($result['id'], $memberData['id']);
+		$this->assertSame($result['circleId'], $circleData['id']);
+		$this->assertSame($result['userId'], self::TEST_USER_2);
+		$this->assertSame($result['userType'], Member::TYPE_USER);
+		$this->assertSame($result['level'], Member::LEVEL_MEMBER);
+	}
+
+	public function testMemberRemove(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
+		$memberService = $this->container->get(MemberService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$user2 = $federatedUserService->generateFederatedUser(self::TEST_USER_2, Member::TYPE_USER);
+		$memberData = $memberService->addMember($circleData['id'], $user2);
+
+		$this->adminController->memberRemove(self::TEST_USER_1, $circleData['id'], $memberData['id']);
+
+		$this->expectException(MemberNotFoundException::class);
+
+		$memberService->getMemberById($memberData['id'], $circleData['id']);
+	}
+
+	public function testMembers(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
+		$memberService = $this->container->get(MemberService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$user2 = $federatedUserService->generateFederatedUser(self::TEST_USER_2, Member::TYPE_USER);
+		$memberService->addMember($circleData['id'], $user2);
+
+		$result = $this->adminController->members(self::TEST_USER_1, $circleData['id'])->getData();
+
+		$this->assertCount(2, $result);
+
+		$userIds = array_column($result, 'userId');
+		$this->assertContains(self::TEST_USER_1, $userIds);
+		$this->assertContains(self::TEST_USER_2, $userIds);
+
+		$circleIds = array_column($result, 'circleId');
+		foreach ($circleIds as $circleId) {
+			$this->assertSame($circleId, $circleData['id']);
+		}
+	}
+
+	public function testEditName(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$result = $this->adminController->editName(self::TEST_USER_1, $circleData['id'], 'test-cricle-new-name')->getData();
+
+		$this->assertSame($result['id'], $circleData['id']);
+		$this->assertSame($result['name'], 'test-cricle-new-name');
+	}
+
+	public function testEditDescription(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$result = $this->adminController->editDescription(self::TEST_USER_1, $circleData['id'], 'test-cricle-new-description')->getData();
+
+		$this->assertSame($result['id'], $circleData['id']);
+		$this->assertSame($result['description'], 'test-cricle-new-description');
+	}
+
+	public function testEditSetting(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$result = $this->adminController->editSetting(self::TEST_USER_1, $circleData['id'], ConfigService::MEMBERS_LIMIT, '25')->getData();
+
+		$this->assertSame($result['id'], $circleData['id']);
+		$this->assertSame($result['settings'][ConfigService::MEMBERS_LIMIT], '25');
+	}
+
+	public function testEditConfig(): void {
+		$circleService = $this->container->get(CircleService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$result = $this->adminController->editConfig(self::TEST_USER_1, $circleData['id'], 128)->getData();
+
+		$this->assertSame($result['id'], $circleData['id']);
+		$this->assertSame($result['config'], 128);
+	}
+
+	public function testLink(): void {
+		$circleService = $this->container->get(CircleService::class);
+		$federatedUserService = $this->container->get(FederatedUserService::class);
+		$memberService = $this->container->get(MemberService::class);
+
+		$circleData = $circleService->create('test-circle');
+		$this->circlesToCleanup[] = $circleData['id'];
+
+		$user2 = $federatedUserService->generateFederatedUser(self::TEST_USER_2, Member::TYPE_USER);
+		$memberData = $memberService->addMember($circleData['id'], $user2);
+
+		// as TEST_USER_1, get membership details of TEST_USER_2
+		$result = $this->adminController->link(self::TEST_USER_1, $circleData['id'], $memberData['singleId'])->getData();
+
+		$this->assertSame($result['circleId'], $circleData['id']);
+		$this->assertSame($result['singleId'], $memberData['singleId']);
+		$this->assertSame($result['level'], Member::LEVEL_MEMBER);
+		$this->assertSame($result['inheritanceDepth'], 1);
 	}
 }