diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index c449bb9..ac6532c 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -5,3 +5,19 @@ add_test(NAME TestDtoTypes COMMAND TestDtoTypes)
 add_executable(TestMulticastDiscovery core/TestMulticastDiscovery.cpp)
 target_link_libraries(TestMulticastDiscovery PRIVATE LocalSendCore Qt6::Test)
 add_test(NAME TestMulticastDiscovery COMMAND TestMulticastDiscovery)
+
+add_executable(TestTypes core/TestTypes.cpp)
+target_link_libraries(TestTypes PRIVATE LocalSendCore Qt6::Test)
+add_test(NAME TestTypes COMMAND TestTypes)
+
+add_executable(TestDevice core/TestDevice.cpp)
+target_link_libraries(TestDevice PRIVATE LocalSendCore Qt6::Test)
+add_test(NAME TestDevice COMMAND TestDevice)
+
+add_executable(TestSessionManager core/TestSessionManager.cpp)
+target_link_libraries(TestSessionManager PRIVATE LocalSendCore Qt6::Test)
+add_test(NAME TestSessionManager COMMAND TestSessionManager)
+
+add_executable(TestDtoTypesExtended core/TestDtoTypesExtended.cpp)
+target_link_libraries(TestDtoTypesExtended PRIVATE LocalSendCore Qt6::Test)
+add_test(NAME TestDtoTypesExtended COMMAND TestDtoTypesExtended)
diff --git a/tests/core/TestDevice.cpp b/tests/core/TestDevice.cpp
new file mode 100644
index 0000000..8f38be3
--- /dev/null
+++ b/tests/core/TestDevice.cpp
@@ -0,0 +1,89 @@
+#include <QtTest>
+#include <LocalSendCore/Device.h>
+
+class TestDevice : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testDefaultConstructor();
+    void testParameterizedConstructor();
+    void testDisplayNameWithAlias();
+    void testDisplayNameWithoutAlias();
+    void testIsHttps();
+    void testEqualityByFingerprint();
+    void testInequality();
+};
+
+void TestDevice::testDefaultConstructor()
+{
+    LocalSend::Device device;
+    QVERIFY(device.ip.isEmpty());
+    QCOMPARE(device.port, quint16(53317));
+    QCOMPARE(device.protocol, LocalSend::ProtocolType::Http);
+    QVERIFY(device.alias.isEmpty());
+    QVERIFY(device.fingerprint.isEmpty());
+    QCOMPARE(device.deviceType, LocalSend::DeviceType::Desktop);
+    QVERIFY(!device.download);
+    QCOMPARE(device.discoveryMethod, LocalSend::DiscoveryMethod::Multicast);
+    QVERIFY(!device.lastSeen.isValid());
+}
+
+void TestDevice::testParameterizedConstructor()
+{
+    LocalSend::Device device(QStringLiteral("192.168.1.100"), 8080);
+    QCOMPARE(device.ip, QStringLiteral("192.168.1.100"));
+    QCOMPARE(device.port, quint16(8080));
+}
+
+void TestDevice::testDisplayNameWithAlias()
+{
+    LocalSend::Device device;
+    device.alias = QStringLiteral("My Laptop");
+    QCOMPARE(device.displayName(), QStringLiteral("My Laptop"));
+}
+
+void TestDevice::testDisplayNameWithoutAlias()
+{
+    LocalSend::Device device;
+    device.ip = QStringLiteral("192.168.1.50");
+    QCOMPARE(device.displayName(), QStringLiteral("192.168.1.50"));
+}
+
+void TestDevice::testIsHttps()
+{
+    LocalSend::Device httpDevice;
+    httpDevice.protocol = LocalSend::ProtocolType::Http;
+    QVERIFY(!httpDevice.isHttps());
+
+    LocalSend::Device httpsDevice;
+    httpsDevice.protocol = LocalSend::ProtocolType::Https;
+    QVERIFY(httpsDevice.isHttps());
+}
+
+void TestDevice::testEqualityByFingerprint()
+{
+    LocalSend::Device a;
+    a.fingerprint = QStringLiteral("fp123");
+    a.ip = QStringLiteral("10.0.0.1");
+
+    LocalSend::Device b;
+    b.fingerprint = QStringLiteral("fp123");
+    b.ip = QStringLiteral("10.0.0.2");
+
+    QVERIFY(a == b);
+}
+
+void TestDevice::testInequality()
+{
+    LocalSend::Device a;
+    a.fingerprint = QStringLiteral("fp1");
+
+    LocalSend::Device b;
+    b.fingerprint = QStringLiteral("fp2");
+
+    QVERIFY(a != b);
+}
+
+QTEST_MAIN(TestDevice)
+#include "TestDevice.moc"
diff --git a/tests/core/TestDtoTypesExtended.cpp b/tests/core/TestDtoTypesExtended.cpp
new file mode 100644
index 0000000..d05c533
--- /dev/null
+++ b/tests/core/TestDtoTypesExtended.cpp
@@ -0,0 +1,181 @@
+#include <QtTest>
+#include <LocalSendCore/DtoTypes.h>
+#include <LocalSendCore/Constants.h>
+#include <QDateTime>
+
+class TestDtoTypesExtended : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testFileDtoMetadata();
+    void testFileDtoRoundTripWithMetadata();
+    void testFileDtoWithoutOptionalFields();
+    void testPrepareUploadResponseDto();
+    void testReceiveRequestResponseDto();
+    void testMulticastDtoVersionDefault();
+    void testFileDtoSizeLarge();
+    void testPrepareUploadRequestDtoRoundTrip();
+};
+
+void TestDtoTypesExtended::testFileDtoMetadata()
+{
+    LocalSend::FileDto dto;
+    dto.id = QStringLiteral("0");
+    dto.fileName = QStringLiteral("test.txt");
+    dto.size = 1024;
+    dto.fileType = QStringLiteral("text/plain");
+    dto.metadata = LocalSend::FileDto::Metadata{
+        QDateTime::fromMSecsSinceEpoch(1700000000000),
+        QDateTime::fromMSecsSinceEpoch(1700000001000)
+    };
+
+    QJsonObject json = dto.toJson();
+    QVERIFY(json.contains(QStringLiteral("metadata")));
+    QJsonObject metaObj = json[QStringLiteral("metadata")].toObject();
+    QCOMPARE(metaObj[QStringLiteral("lastModified")].toVariant().toLongLong(), qint64(1700000000000));
+    QCOMPARE(metaObj[QStringLiteral("lastAccessed")].toVariant().toLongLong(), qint64(1700000001000));
+}
+
+void TestDtoTypesExtended::testFileDtoRoundTripWithMetadata()
+{
+    LocalSend::FileDto dto;
+    dto.id = QStringLiteral("1");
+    dto.fileName = QStringLiteral("doc.pdf");
+    dto.size = 2048;
+    dto.fileType = QStringLiteral("application/pdf");
+    dto.hash = QStringLiteral("abc123");
+    dto.preview = QStringLiteral("base64data");
+    dto.metadata = LocalSend::FileDto::Metadata{
+        QDateTime::fromMSecsSinceEpoch(1700000000000),
+        QDateTime()
+    };
+
+    QJsonObject json = dto.toJson();
+    LocalSend::FileDto parsed = LocalSend::FileDto::fromJson(json);
+
+    QCOMPARE(parsed.id, dto.id);
+    QCOMPARE(parsed.fileName, dto.fileName);
+    QCOMPARE(parsed.size, dto.size);
+    QCOMPARE(parsed.fileType, dto.fileType);
+    QCOMPARE(parsed.hash, dto.hash);
+    QCOMPARE(parsed.preview, dto.preview);
+    QVERIFY(parsed.metadata.has_value());
+    QCOMPARE(parsed.metadata->lastModified.toMSecsSinceEpoch(), qint64(1700000000000));
+    QVERIFY(!parsed.metadata->lastAccessed.isValid());
+}
+
+void TestDtoTypesExtended::testFileDtoWithoutOptionalFields()
+{
+    LocalSend::FileDto dto;
+    dto.id = QStringLiteral("2");
+    dto.fileName = QStringLiteral("simple.txt");
+    dto.size = 50;
+    dto.fileType = QStringLiteral("text/plain");
+
+    QJsonObject json = dto.toJson();
+    QVERIFY(!json.contains(QStringLiteral("hash")));
+    QVERIFY(!json.contains(QStringLiteral("preview")));
+    QVERIFY(!json.contains(QStringLiteral("metadata")));
+
+    LocalSend::FileDto parsed = LocalSend::FileDto::fromJson(json);
+    QVERIFY(!parsed.metadata.has_value());
+    QVERIFY(parsed.hash.isEmpty());
+    QVERIFY(parsed.preview.isEmpty());
+}
+
+void TestDtoTypesExtended::testPrepareUploadResponseDto()
+{
+    QJsonObject json;
+    json[QStringLiteral("sessionId")] = QStringLiteral("sess-123");
+    QJsonObject filesObj;
+    filesObj[QStringLiteral("0")] = QStringLiteral("token-0");
+    filesObj[QStringLiteral("1")] = QStringLiteral("token-1");
+    json[QStringLiteral("files")] = filesObj;
+
+    LocalSend::PrepareUploadResponseDto dto = LocalSend::PrepareUploadResponseDto::fromJson(json);
+
+    QCOMPARE(dto.sessionId, QStringLiteral("sess-123"));
+    QCOMPARE(dto.files.size(), 2);
+    QCOMPARE(dto.files[QStringLiteral("0")], QStringLiteral("token-0"));
+    QCOMPARE(dto.files[QStringLiteral("1")], QStringLiteral("token-1"));
+}
+
+void TestDtoTypesExtended::testReceiveRequestResponseDto()
+{
+    LocalSend::ReceiveRequestResponseDto dto;
+    dto.sessionId = QStringLiteral("sess-456");
+    dto.cancel = false;
+    dto.destinationPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/file0.txt"));
+    dto.destinationPaths.insert(QStringLiteral("1"), QStringLiteral("/tmp/file1.txt"));
+
+    QJsonObject json = dto.toJson();
+    QCOMPARE(json[QStringLiteral("sessionId")].toString(), QStringLiteral("sess-456"));
+    QCOMPARE(json[QStringLiteral("cancel")].toBool(), false);
+
+    QJsonObject pathsObj = json[QStringLiteral("destinationPaths")].toObject();
+    QCOMPARE(pathsObj.size(), 2);
+    QCOMPARE(pathsObj[QStringLiteral("0")].toString(), QStringLiteral("/tmp/file0.txt"));
+}
+
+void TestDtoTypesExtended::testMulticastDtoVersionDefault()
+{
+    LocalSend::MulticastDto dto;
+    dto.alias = QStringLiteral("Test");
+    dto.fingerprint = QStringLiteral("fp1");
+
+    QJsonObject json = dto.toJson();
+    QCOMPARE(json[QStringLiteral("version")].toString(), QString(LocalSend::PROTOCOL_VERSION));
+}
+
+void TestDtoTypesExtended::testFileDtoSizeLarge()
+{
+    LocalSend::FileDto dto;
+    dto.id = QStringLiteral("big");
+    dto.fileName = QStringLiteral("big.iso");
+    dto.size = Q_INT64_C(4700000000);
+    dto.fileType = QStringLiteral("application/x-iso9660-image");
+
+    QJsonObject json = dto.toJson();
+    LocalSend::FileDto parsed = LocalSend::FileDto::fromJson(json);
+    QCOMPARE(parsed.size, Q_INT64_C(4700000000));
+}
+
+void TestDtoTypesExtended::testPrepareUploadRequestDtoRoundTrip()
+{
+    LocalSend::PrepareUploadRequestDto dto;
+    dto.info.alias = QStringLiteral("Alice");
+    dto.info.fingerprint = QStringLiteral("fp-alice");
+    dto.info.port = 53317;
+    dto.info.protocol = LocalSend::ProtocolType::Https;
+
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("photo.jpg");
+    f1.size = 3000000;
+    f1.fileType = QStringLiteral("image/jpeg");
+    dto.files.insert(QStringLiteral("0"), f1);
+
+    LocalSend::FileDto f2;
+    f2.id = QStringLiteral("1");
+    f2.fileName = QStringLiteral("notes.txt");
+    f2.size = 500;
+    f2.fileType = QStringLiteral("text/plain");
+    f2.hash = QStringLiteral("sha256abc");
+    dto.files.insert(QStringLiteral("1"), f2);
+
+    QJsonObject json = dto.toJson();
+    LocalSend::PrepareUploadRequestDto parsed = LocalSend::PrepareUploadRequestDto::fromJson(json);
+
+    QCOMPARE(parsed.info.alias, QStringLiteral("Alice"));
+    QCOMPARE(parsed.info.fingerprint, QStringLiteral("fp-alice"));
+    QCOMPARE(parsed.info.port, quint16(53317));
+    QCOMPARE(parsed.info.protocol, LocalSend::ProtocolType::Https);
+    QCOMPARE(parsed.files.size(), 2);
+    QCOMPARE(parsed.files[QStringLiteral("0")].fileName, QStringLiteral("photo.jpg"));
+    QCOMPARE(parsed.files[QStringLiteral("0")].size, qint64(3000000));
+    QCOMPARE(parsed.files[QStringLiteral("1")].hash, QStringLiteral("sha256abc"));
+}
+
+QTEST_MAIN(TestDtoTypesExtended)
+#include "TestDtoTypesExtended.moc"
diff --git a/tests/core/TestSessionManager.cpp b/tests/core/TestSessionManager.cpp
new file mode 100644
index 0000000..00933cf
--- /dev/null
+++ b/tests/core/TestSessionManager.cpp
@@ -0,0 +1,552 @@
+#include <QtTest>
+#include <LocalSendCore/SessionManager.h>
+#include <LocalSendCore/Device.h>
+
+class TestSessionManager : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testCreateReceiveSession();
+    void testAcceptReceiveSession();
+    void testDeclineReceiveSession();
+    void testCancelReceiveSession();
+    void testReceiveProgress();
+    void testCompleteReceiveFile();
+    void testCompleteAllReceiveFiles();
+    void testFailReceiveFile();
+    void testCreateSendSession();
+    void testSetSendSessionTokens();
+    void testStartSendSession();
+    void testSendProgress();
+    void testCompleteSendFile();
+    void testCompleteAllSendFiles();
+    void testCancelSendSession();
+    void testHasSessionQueries();
+    void testGenerateToken();
+    void testDeclineRemovesSession();
+    void testSetSendSessionTokensRekeys();
+};
+
+void TestSessionManager::testCreateReceiveSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    sender.ip = QStringLiteral("10.0.0.1");
+    sender.alias = QStringLiteral("Sender");
+
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    LocalSend::FileDto f2;
+    f2.id = QStringLiteral("1");
+    f2.fileName = QStringLiteral("b.txt");
+    f2.size = 200;
+    files.insert(QStringLiteral("1"), f2);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveSessionCreated);
+    QString sessionId = mgr.createReceiveSession(sender, files);
+
+    QVERIFY(!sessionId.isEmpty());
+    QCOMPARE(spy.count(), 1);
+
+    LocalSend::ReceiveSession session = mgr.receiveSession(sessionId);
+    QCOMPARE(session.sessionId, sessionId);
+    QCOMPARE(session.sender.alias, QStringLiteral("Sender"));
+    QCOMPARE(session.files.size(), 2);
+    QCOMPARE(session.status, LocalSend::SessionStatus::Waiting);
+    QVERIFY(!session.files[QStringLiteral("0")].token.isEmpty());
+    QVERIFY(!session.files[QStringLiteral("1")].token.isEmpty());
+}
+
+void TestSessionManager::testAcceptReceiveSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveSessionAccepted);
+    QMap<QString, QString> destPaths;
+    destPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    mgr.acceptReceiveSession(sessionId, destPaths);
+
+    QCOMPARE(spy.count(), 1);
+    QList<QVariant> args = spy.takeFirst();
+    QCOMPARE(args.at(0).toString(), sessionId);
+
+    LocalSend::ReceiveSession session = mgr.receiveSession(sessionId);
+    QCOMPARE(session.status, LocalSend::SessionStatus::Sending);
+    QCOMPARE(session.files[QStringLiteral("0")].destinationPath, QStringLiteral("/tmp/a.txt"));
+
+    auto tokens = args.at(1).value<QMap<QString, QString>>();
+    QVERIFY(!tokens.value(QStringLiteral("0")).isEmpty());
+}
+
+void TestSessionManager::testDeclineReceiveSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveSessionDeclined);
+    mgr.declineReceiveSession(sessionId);
+
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasReceiveSession(sessionId));
+}
+
+void TestSessionManager::testCancelReceiveSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+    QMap<QString, QString> destPaths;
+    destPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    mgr.acceptReceiveSession(sessionId, destPaths);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveSessionCanceled);
+    mgr.cancelReceiveSession(sessionId);
+
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasReceiveSession(sessionId));
+}
+
+void TestSessionManager::testReceiveProgress()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 1000;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+    QMap<QString, QString> destPaths;
+    destPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    mgr.acceptReceiveSession(sessionId, destPaths);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveProgress);
+    mgr.updateReceiveProgress(sessionId, QStringLiteral("0"), 500);
+
+    QCOMPARE(spy.count(), 1);
+    double progress = spy.takeFirst().at(2).toDouble();
+    QVERIFY(qFuzzyCompare(progress, 0.5));
+}
+
+void TestSessionManager::testCompleteReceiveFile()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 1000;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+    QMap<QString, QString> destPaths;
+    destPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    mgr.acceptReceiveSession(sessionId, destPaths);
+
+    mgr.updateReceiveProgress(sessionId, QStringLiteral("0"), 1000);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveSessionCompleted);
+    mgr.completeReceiveFile(sessionId, QStringLiteral("0"));
+
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasReceiveSession(sessionId));
+}
+
+void TestSessionManager::testCompleteAllReceiveFiles()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    LocalSend::FileDto f2;
+    f2.id = QStringLiteral("1");
+    f2.fileName = QStringLiteral("b.txt");
+    f2.size = 200;
+    files.insert(QStringLiteral("1"), f2);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+    QMap<QString, QString> destPaths;
+    destPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    destPaths.insert(QStringLiteral("1"), QStringLiteral("/tmp/b.txt"));
+    mgr.acceptReceiveSession(sessionId, destPaths);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::receiveSessionCompleted);
+
+    mgr.completeReceiveFile(sessionId, QStringLiteral("0"));
+    QCOMPARE(spy.count(), 0);
+    QVERIFY(mgr.hasReceiveSession(sessionId));
+
+    mgr.completeReceiveFile(sessionId, QStringLiteral("1"));
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasReceiveSession(sessionId));
+}
+
+void TestSessionManager::testFailReceiveFile()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 1000;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+
+    mgr.failReceiveFile(sessionId, QStringLiteral("0"));
+
+    LocalSend::ReceiveSession session = mgr.receiveSession(sessionId);
+    QCOMPARE(session.files[QStringLiteral("0")].status, LocalSend::FileStatus::Failed);
+}
+
+void TestSessionManager::testCreateSendSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    target.ip = QStringLiteral("10.0.0.2");
+    target.alias = QStringLiteral("Receiver");
+
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("c.txt");
+    f1.size = 500;
+    files.insert(QStringLiteral("0"), f1);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/home/user/c.txt"));
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::sendSessionCreated);
+    QString sessionId = mgr.createSendSession(target, files, localPaths);
+
+    QVERIFY(!sessionId.isEmpty());
+    QCOMPARE(spy.count(), 1);
+
+    LocalSend::SendSession session = mgr.sendSession(sessionId);
+    QCOMPARE(session.sessionId, sessionId);
+    QCOMPARE(session.target.alias, QStringLiteral("Receiver"));
+    QCOMPARE(session.files.size(), 1);
+    QCOMPARE(session.files[QStringLiteral("0")].localPath, QStringLiteral("/home/user/c.txt"));
+    QCOMPARE(session.status, LocalSend::SessionStatus::Waiting);
+}
+
+void TestSessionManager::testSetSendSessionTokens()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+
+    QString origSessionId = mgr.createSendSession(target, files, localPaths);
+
+    QString responseSessionId = QStringLiteral("server-session-123");
+    QMap<QString, QString> tokens;
+    tokens.insert(QStringLiteral("0"), QStringLiteral("token-abc"));
+
+    mgr.setSendSessionTokens(origSessionId, responseSessionId, tokens);
+
+    QVERIFY(!mgr.hasSendSession(origSessionId));
+    QVERIFY(mgr.hasSendSession(responseSessionId));
+
+    LocalSend::SendSession session = mgr.sendSession(responseSessionId);
+    QCOMPARE(session.sessionId, responseSessionId);
+    QCOMPARE(session.files[QStringLiteral("0")].token, QStringLiteral("token-abc"));
+}
+
+void TestSessionManager::testStartSendSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+
+    QString sessionId = mgr.createSendSession(target, files, localPaths);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::sendSessionStarted);
+    mgr.startSendSession(sessionId);
+
+    QCOMPARE(spy.count(), 1);
+    LocalSend::SendSession session = mgr.sendSession(sessionId);
+    QCOMPARE(session.status, LocalSend::SessionStatus::Sending);
+}
+
+void TestSessionManager::testSendProgress()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 2000;
+    files.insert(QStringLiteral("0"), f1);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+
+    QString sessionId = mgr.createSendSession(target, files, localPaths);
+    mgr.startSendSession(sessionId);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::sendProgress);
+    mgr.updateSendProgress(sessionId, QStringLiteral("0"), 1000);
+
+    QCOMPARE(spy.count(), 1);
+    double progress = spy.takeFirst().at(2).toDouble();
+    QVERIFY(qFuzzyCompare(progress, 0.5));
+}
+
+void TestSessionManager::testCompleteSendFile()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 1000;
+    files.insert(QStringLiteral("0"), f1);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+
+    QString sessionId = mgr.createSendSession(target, files, localPaths);
+    mgr.startSendSession(sessionId);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::sendSessionCompleted);
+    mgr.completeSendFile(sessionId, QStringLiteral("0"));
+
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasSendSession(sessionId));
+}
+
+void TestSessionManager::testCompleteAllSendFiles()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    LocalSend::FileDto f2;
+    f2.id = QStringLiteral("1");
+    f2.fileName = QStringLiteral("b.txt");
+    f2.size = 200;
+    files.insert(QStringLiteral("1"), f2);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    localPaths.insert(QStringLiteral("1"), QStringLiteral("/tmp/b.txt"));
+
+    QString sessionId = mgr.createSendSession(target, files, localPaths);
+    mgr.startSendSession(sessionId);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::sendSessionCompleted);
+
+    mgr.completeSendFile(sessionId, QStringLiteral("0"));
+    QCOMPARE(spy.count(), 0);
+
+    mgr.completeSendFile(sessionId, QStringLiteral("1"));
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasSendSession(sessionId));
+}
+
+void TestSessionManager::testCancelSendSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+
+    QString sessionId = mgr.createSendSession(target, files, localPaths);
+    mgr.startSendSession(sessionId);
+
+    QSignalSpy spy(&mgr, &LocalSend::SessionManager::sendSessionCanceled);
+    mgr.cancelSendSession(sessionId);
+
+    QCOMPARE(spy.count(), 1);
+    QVERIFY(!mgr.hasSendSession(sessionId));
+}
+
+void TestSessionManager::testHasSessionQueries()
+{
+    LocalSend::SessionManager mgr;
+
+    QVERIFY(!mgr.hasReceiveSession(QStringLiteral("nonexistent")));
+    QVERIFY(!mgr.hasSendSession(QStringLiteral("nonexistent")));
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString recvSessionId = mgr.createReceiveSession(sender, files);
+    QVERIFY(mgr.hasReceiveSession(recvSessionId));
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    QString sendSessionId = mgr.createSendSession(sender, files, localPaths);
+    QVERIFY(mgr.hasSendSession(sendSessionId));
+
+    LocalSend::ReceiveSession emptyRecv = mgr.receiveSession(QStringLiteral("nope"));
+    QVERIFY(emptyRecv.sessionId.isEmpty());
+
+    LocalSend::SendSession emptySend = mgr.sendSession(QStringLiteral("nope"));
+    QVERIFY(emptySend.sessionId.isEmpty());
+}
+
+void TestSessionManager::testGenerateToken()
+{
+    LocalSend::SessionManager mgr;
+
+    QString token1 = mgr.generateToken();
+    QString token2 = mgr.generateToken();
+
+    QVERIFY(!token1.isEmpty());
+    QVERIFY(!token2.isEmpty());
+    QVERIFY(token1 != token2);
+}
+
+void TestSessionManager::testDeclineRemovesSession()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device sender;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    QString sessionId = mgr.createReceiveSession(sender, files);
+    QVERIFY(mgr.hasReceiveSession(sessionId));
+
+    mgr.declineReceiveSession(sessionId);
+    QVERIFY(!mgr.hasReceiveSession(sessionId));
+}
+
+void TestSessionManager::testSetSendSessionTokensRekeys()
+{
+    LocalSend::SessionManager mgr;
+
+    LocalSend::Device target;
+    QMap<QString, LocalSend::FileDto> files;
+    LocalSend::FileDto f1;
+    f1.id = QStringLiteral("0");
+    f1.fileName = QStringLiteral("a.txt");
+    f1.size = 100;
+    files.insert(QStringLiteral("0"), f1);
+
+    LocalSend::FileDto f2;
+    f2.id = QStringLiteral("1");
+    f2.fileName = QStringLiteral("b.txt");
+    f2.size = 200;
+    files.insert(QStringLiteral("1"), f2);
+
+    QMap<QString, QString> localPaths;
+    localPaths.insert(QStringLiteral("0"), QStringLiteral("/tmp/a.txt"));
+    localPaths.insert(QStringLiteral("1"), QStringLiteral("/tmp/b.txt"));
+
+    QString origId = mgr.createSendSession(target, files, localPaths);
+
+    QString newId = QStringLiteral("response-session-id");
+    QMap<QString, QString> tokens;
+    tokens.insert(QStringLiteral("0"), QStringLiteral("tok0"));
+    tokens.insert(QStringLiteral("1"), QStringLiteral("tok1"));
+
+    mgr.setSendSessionTokens(origId, newId, tokens);
+
+    QVERIFY(!mgr.hasSendSession(origId));
+    QVERIFY(mgr.hasSendSession(newId));
+
+    LocalSend::SendSession session = mgr.sendSession(newId);
+    QCOMPARE(session.sessionId, newId);
+    QCOMPARE(session.files[QStringLiteral("0")].token, QStringLiteral("tok0"));
+    QCOMPARE(session.files[QStringLiteral("1")].token, QStringLiteral("tok1"));
+    QCOMPARE(session.files[QStringLiteral("0")].localPath, QStringLiteral("/tmp/a.txt"));
+    QCOMPARE(session.files[QStringLiteral("1")].localPath, QStringLiteral("/tmp/b.txt"));
+}
+
+QTEST_MAIN(TestSessionManager)
+#include "TestSessionManager.moc"
diff --git a/tests/core/TestTypes.cpp b/tests/core/TestTypes.cpp
new file mode 100644
index 0000000..b98a843
--- /dev/null
+++ b/tests/core/TestTypes.cpp
@@ -0,0 +1,82 @@
+#include <QtTest>
+#include <LocalSendCore/Types.h>
+
+class TestTypes : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testDeviceTypeToString();
+    void testDeviceTypeFromString();
+    void testDeviceTypeRoundTrip();
+    void testDeviceTypeFromStringUnknown();
+    void testProtocolTypeToString();
+    void testProtocolTypeFromString();
+    void testProtocolTypeRoundTrip();
+    void testProtocolTypeFromStringUnknown();
+};
+
+void TestTypes::testDeviceTypeToString()
+{
+    QCOMPARE(LocalSend::deviceTypeToString(LocalSend::DeviceType::Mobile), QStringLiteral("mobile"));
+    QCOMPARE(LocalSend::deviceTypeToString(LocalSend::DeviceType::Desktop), QStringLiteral("desktop"));
+    QCOMPARE(LocalSend::deviceTypeToString(LocalSend::DeviceType::Web), QStringLiteral("web"));
+    QCOMPARE(LocalSend::deviceTypeToString(LocalSend::DeviceType::Headless), QStringLiteral("headless"));
+    QCOMPARE(LocalSend::deviceTypeToString(LocalSend::DeviceType::Server), QStringLiteral("server"));
+}
+
+void TestTypes::testDeviceTypeFromString()
+{
+    QCOMPARE(LocalSend::deviceTypeFromString(QStringLiteral("mobile")), LocalSend::DeviceType::Mobile);
+    QCOMPARE(LocalSend::deviceTypeFromString(QStringLiteral("desktop")), LocalSend::DeviceType::Desktop);
+    QCOMPARE(LocalSend::deviceTypeFromString(QStringLiteral("web")), LocalSend::DeviceType::Web);
+    QCOMPARE(LocalSend::deviceTypeFromString(QStringLiteral("headless")), LocalSend::DeviceType::Headless);
+    QCOMPARE(LocalSend::deviceTypeFromString(QStringLiteral("server")), LocalSend::DeviceType::Server);
+}
+
+void TestTypes::testDeviceTypeRoundTrip()
+{
+    const QList<LocalSend::DeviceType> types = {
+        LocalSend::DeviceType::Mobile,
+        LocalSend::DeviceType::Desktop,
+        LocalSend::DeviceType::Web,
+        LocalSend::DeviceType::Headless,
+        LocalSend::DeviceType::Server,
+    };
+    for (const auto& type : types) {
+        QCOMPARE(LocalSend::deviceTypeFromString(LocalSend::deviceTypeToString(type)), type);
+    }
+}
+
+void TestTypes::testDeviceTypeFromStringUnknown()
+{
+    QCOMPARE(LocalSend::deviceTypeFromString(QStringLiteral("unknown")), LocalSend::DeviceType::Desktop);
+    QCOMPARE(LocalSend::deviceTypeFromString(QString()), LocalSend::DeviceType::Desktop);
+}
+
+void TestTypes::testProtocolTypeToString()
+{
+    QCOMPARE(LocalSend::protocolTypeToString(LocalSend::ProtocolType::Http), QStringLiteral("http"));
+    QCOMPARE(LocalSend::protocolTypeToString(LocalSend::ProtocolType::Https), QStringLiteral("https"));
+}
+
+void TestTypes::testProtocolTypeFromString()
+{
+    QCOMPARE(LocalSend::protocolTypeFromString(QStringLiteral("http")), LocalSend::ProtocolType::Http);
+    QCOMPARE(LocalSend::protocolTypeFromString(QStringLiteral("https")), LocalSend::ProtocolType::Https);
+}
+
+void TestTypes::testProtocolTypeRoundTrip()
+{
+    QCOMPARE(LocalSend::protocolTypeFromString(LocalSend::protocolTypeToString(LocalSend::ProtocolType::Http)), LocalSend::ProtocolType::Http);
+    QCOMPARE(LocalSend::protocolTypeFromString(LocalSend::protocolTypeToString(LocalSend::ProtocolType::Https)), LocalSend::ProtocolType::Https);
+}
+
+void TestTypes::testProtocolTypeFromStringUnknown()
+{
+    QCOMPARE(LocalSend::protocolTypeFromString(QStringLiteral("ftp")), LocalSend::ProtocolType::Http);
+    QCOMPARE(LocalSend::protocolTypeFromString(QString()), LocalSend::ProtocolType::Http);
+}
+
+QTEST_MAIN(TestTypes)
+#include "TestTypes.moc"