GH-3392 dirty initial MSA support that shares logic with Mojang flows

Both act as the first step of AuthContext.

63 files changed, 2323 insertions, 2466 deletions

diff --git a/launcher/BaseInstance.h b/launcher/BaseInstance.h
index 833646c0..8c08dc05 100644
--- a/launcher/BaseInstance.h
+++ b/launcher/BaseInstance.h
@@ -26,7 +26,7 @@
 
 #include "settings/INIFile.h"
 #include "BaseVersionList.h"
-#include "minecraft/auth/MojangAccount.h"
+#include "minecraft/auth/MinecraftAccount.h"
 #include "MessageLevel.h"
 #include "pathmatcher/IPathMatcher.h"
 
diff --git a/launcher/CMakeLists.txt b/launcher/CMakeLists.txt
index 37f5d3a1..3c140ede 100644
--- a/launcher/CMakeLists.txt
+++ b/launcher/CMakeLists.txt
@@ -203,20 +203,31 @@ set(STATUS_SOURCES
 # Support for Minecraft instances and launch
 set(MINECRAFT_SOURCES
     # Minecraft support
+    minecraft/auth/AccountData.h
+    minecraft/auth/AccountData.cpp
+    minecraft/auth/AccountTask.h
+    minecraft/auth/AccountTask.cpp
     minecraft/auth/AuthSession.h
     minecraft/auth/AuthSession.cpp
-    minecraft/auth/MojangAccountList.h
-    minecraft/auth/MojangAccountList.cpp
-    minecraft/auth/MojangAccount.h
-    minecraft/auth/MojangAccount.cpp
-    minecraft/auth/YggdrasilTask.h
-    minecraft/auth/YggdrasilTask.cpp
-    minecraft/auth/flows/AuthenticateTask.h
-    minecraft/auth/flows/AuthenticateTask.cpp
-    minecraft/auth/flows/RefreshTask.cpp
-    minecraft/auth/flows/RefreshTask.cpp
-    minecraft/auth/flows/ValidateTask.h
-    minecraft/auth/flows/ValidateTask.cpp
+    minecraft/auth/AccountList.h
+    minecraft/auth/AccountList.cpp
+    minecraft/auth/MinecraftAccount.h
+    minecraft/auth/MinecraftAccount.cpp
+    minecraft/auth/flows/AuthContext.h
+    minecraft/auth/flows/AuthContext.cpp
+
+    minecraft/auth/flows/MSAInteractive.h
+    minecraft/auth/flows/MSAInteractive.cpp
+    minecraft/auth/flows/MSASilent.h
+    minecraft/auth/flows/MSASilent.cpp
+
+    minecraft/auth/flows/MojangLogin.h
+    minecraft/auth/flows/MojangLogin.cpp
+    minecraft/auth/flows/MojangRefresh.h
+    minecraft/auth/flows/MojangRefresh.cpp
+
+    minecraft/auth/flows/Yggdrasil.h
+    minecraft/auth/flows/Yggdrasil.cpp
 
     minecraft/gameoptions/GameOptions.h
     minecraft/gameoptions/GameOptions.cpp
@@ -732,6 +743,8 @@ SET(MULTIMC_SOURCES
     dialogs/IconPickerDialog.h
     dialogs/LoginDialog.cpp
     dialogs/LoginDialog.h
+    dialogs/MSALoginDialog.cpp
+    dialogs/MSALoginDialog.h
     dialogs/NewComponentDialog.cpp
     dialogs/NewComponentDialog.h
     dialogs/NewInstanceDialog.cpp
@@ -850,6 +863,7 @@ SET(MULTIMC_UIS
     dialogs/EditAccountDialog.ui
     dialogs/ExportInstanceDialog.ui
     dialogs/LoginDialog.ui
+    dialogs/MSALoginDialog.ui
     dialogs/UpdateDialog.ui
     dialogs/NotificationDialog.ui
     dialogs/SkinUploadDialog.ui
@@ -892,6 +906,7 @@ target_link_libraries(MultiMC_logic
     optional-bare
     tomlc99
     BuildConfig
+    Katabasis
 )
 target_link_libraries(MultiMC_logic
     Qt5::Core
diff --git a/launcher/Env.cpp b/launcher/Env.cpp
index 71b49d95..abf9f58c 100644
--- a/launcher/Env.cpp
+++ b/launcher/Env.cpp
@@ -101,7 +101,6 @@ void Env::initHttpMetaCache()
     m_metacache->addBase("ModpacksCHPacks", QDir("cache/ModpacksCHPacks").absolutePath());
     m_metacache->addBase("TechnicPacks", QDir("cache/TechnicPacks").absolutePath());
     m_metacache->addBase("FlamePacks", QDir("cache/FlamePacks").absolutePath());
-    m_metacache->addBase("skins", QDir("accounts/skins").absolutePath());
     m_metacache->addBase("root", QDir::currentPath());
     m_metacache->addBase("translations", QDir("translations").absolutePath());
     m_metacache->addBase("icons", QDir("cache/icons").absolutePath());
diff --git a/launcher/LaunchController.cpp b/launcher/LaunchController.cpp
index ee764082..11780625 100644
--- a/launcher/LaunchController.cpp
+++ b/launcher/LaunchController.cpp
@@ -1,6 +1,6 @@
 #include "LaunchController.h"
 #include "MainWindow.h"
-#include <minecraft/auth/MojangAccountList.h>
+#include <minecraft/auth/AccountList.h>
 #include "MultiMC.h"
 #include "dialogs/CustomMessageBox.h"
 #include "dialogs/ProfileSelectDialog.h"
@@ -12,7 +12,7 @@
 #include <QLineEdit>
 #include <QInputDialog>
 #include <tasks/Task.h>
-#include <minecraft/auth/YggdrasilTask.h>
+#include <minecraft/auth/AccountTask.h>
 #include <launch/steps/TextPrint.h>
 #include <QStringList>
 #include <QHostInfo>
@@ -35,22 +35,23 @@ void LaunchController::executeTask()
 }
 
 // FIXME: minecraft specific
-void LaunchController::login()
-{
+void LaunchController::login() {
     JavaCommon::checkJVMArgs(m_instance->settings()->get("JvmArgs").toString(), m_parentWidget);
 
     // Find an account to use.
-    std::shared_ptr<MojangAccountList> accounts = MMC->accounts();
-    MojangAccountPtr account = accounts->activeAccount();
+    std::shared_ptr<AccountList> accounts = MMC->accounts();
     if (accounts->count() <= 0)
     {
         // Tell the user they need to log in at least one account in order to play.
         auto reply = CustomMessageBox::selectable(
-            m_parentWidget, tr("No Accounts"),
+            m_parentWidget,
+            tr("No Accounts"),
             tr("In order to play Minecraft, you must have at least one Mojang or Minecraft "
                "account logged in to MultiMC."
                "Would you like to open the account manager to add an account now?"),
-            QMessageBox::Information, QMessageBox::Yes | QMessageBox::No)->exec();
+            QMessageBox::Information,
+            QMessageBox::Yes | QMessageBox::No
+        )->exec();
 
         if (reply == QMessageBox::Yes)
         {
@@ -58,11 +59,16 @@ void LaunchController::login()
             MMC->ShowGlobalSettings(m_parentWidget, "accounts");
         }
     }
-    else if (account.get() == nullptr)
+
+    MinecraftAccountPtr account = accounts->activeAccount();
+    if (account.get() == nullptr)
     {
         // If no default account is set, ask the user which one to use.
-        ProfileSelectDialog selectDialog(tr("Which profile would you like to use?"),
-                                         ProfileSelectDialog::GlobalDefaultCheckbox, m_parentWidget);
+        ProfileSelectDialog selectDialog(
+            tr("Which account would you like to use?"),
+            ProfileSelectDialog::GlobalDefaultCheckbox,
+            m_parentWidget
+        );
 
         selectDialog.exec();
 
@@ -70,8 +76,9 @@ void LaunchController::login()
         account = selectDialog.selectedAccount();
 
         // If the user said to use the account as default, do that.
-        if (selectDialog.useAsGlobalDefault() && account.get() != nullptr)
-            accounts->setActiveAccount(account->username());
+        if (selectDialog.useAsGlobalDefault() && account.get() != nullptr) {
+            accounts->setActiveAccount(account->profileId());
+        }
     }
 
     // if no account is selected, we bail
@@ -93,7 +100,13 @@ void LaunchController::login()
     {
         m_session = std::make_shared<AuthSession>();
         m_session->wants_online = m_online;
-        auto task = account->login(m_session, password);
+        std::shared_ptr<AccountTask> task;
+        if(!password.isNull()) {
+            task = account->login(m_session, password);
+        }
+        else {
+            task = account->refresh(m_session);
+        }
         if (task)
         {
             // We'll need to validate the access token to make sure the account
@@ -107,9 +120,9 @@ void LaunchController::login()
             if (!task->wasSuccessful())
             {
                 auto failReasonNew = task->failReason();
-                if(failReasonNew == "Invalid token.")
+                if(failReasonNew == "Invalid token." || failReasonNew == "Invalid Signature")
                 {
-                    account->invalidateClientToken();
+                    // account->invalidateClientToken();
                     failReason = needLoginAgain;
                 }
                 else failReason = failReasonNew;
@@ -117,72 +130,82 @@ void LaunchController::login()
         }
         switch (m_session->status)
         {
-        case AuthSession::Undetermined:
-        {
-            qCritical() << "Received undetermined session status during login. Bye.";
-            tryagain = false;
-            emitFailed(tr("Received undetermined session status during login."));
-            break;
-        }
-        case AuthSession::RequiresPassword:
-        {
-            EditAccountDialog passDialog(failReason, m_parentWidget, EditAccountDialog::PasswordField);
-            auto username = m_session->username;
-            auto chopN = [](QString toChop, int N) -> QString
-            {
-                if(toChop.size() > N)
+            case AuthSession::Undetermined: {
+                qCritical() << "Received undetermined session status during login. Bye.";
+                tryagain = false;
+                emitFailed(tr("Received undetermined session status during login."));
+                return;
+            }
+            case AuthSession::RequiresPassword: {
+                // FIXME: this needs to understand MSA
+                EditAccountDialog passDialog(failReason, m_parentWidget, EditAccountDialog::PasswordField);
+                auto username = m_session->username;
+                auto chopN = [](QString toChop, int N) -> QString
                 {
-                    auto left = toChop.left(N);
-                    left += QString("\u25CF").repeated(toChop.size() - N);
-                    return left;
-                }
-                return toChop;
-            };
+                    if(toChop.size() > N)
+                    {
+                        auto left = toChop.left(N);
+                        left += QString("\u25CF").repeated(toChop.size() - N);
+                        return left;
+                    }
+                    return toChop;
+                };
 
-            if(username.contains('@'))
-            {
-                auto parts = username.split('@');
-                auto mailbox = chopN(parts[0],3);
-                QString domain = chopN(parts[1], 3);
-                username = mailbox + '@' + domain;
-            }
-            passDialog.setUsername(username);
-            if (passDialog.exec() == QDialog::Accepted)
-            {
-                password = passDialog.password();
+                if(username.contains('@'))
+                {
+                    auto parts = username.split('@');
+                    auto mailbox = chopN(parts[0],3);
+                    QString domain = chopN(parts[1], 3);
+                    username = mailbox + '@' + domain;
+                }
+                passDialog.setUsername(username);
+                if (passDialog.exec() == QDialog::Accepted)
+                {
+                    password = passDialog.password();
+                }
+                else
+                {
+                    tryagain = false;
+                    emitFailed(tr("Received undetermined session status during login."));
+                }
+                break;
             }
-            else
-            {
+            case AuthSession::RequiresOAuth: {
+                // FIXME: add UI for expired / broken MS accounts
                 tryagain = false;
+                emitFailed(tr("Microsoft account has expired and needs to be logged into again."));
+                return;
             }
-            break;
-        }
-        case AuthSession::PlayableOffline:
-        {
-            // we ask the user for a player name
-            bool ok = false;
-            QString usedname = m_session->player_name;
-            QString name = QInputDialog::getText(m_parentWidget, tr("Player name"),
-                                                 tr("Choose your offline mode player name."),
-                                                 QLineEdit::Normal, m_session->player_name, &ok);
-            if (!ok)
-            {
-                tryagain = false;
-                break;
+            case AuthSession::PlayableOffline: {
+                // we ask the user for a player name
+                bool ok = false;
+                QString usedname = m_session->player_name;
+                QString name = QInputDialog::getText(
+                    m_parentWidget,
+                    tr("Player name"),
+                    tr("Choose your offline mode player name."),
+                    QLineEdit::Normal,
+                    m_session->player_name,
+                    &ok
+                );
+                if (!ok)
+                {
+                    tryagain = false;
+                    break;
+                }
+                if (name.length())
+                {
+                    usedname = name;
+                }
+                m_session->MakeOffline(usedname);
+                // offline flavored game from here :3
             }
-            if (name.length())
+            case AuthSession::PlayableOnline:
             {
-                usedname = name;
+                launchInstance();
+                tryagain = false;
+                return;
             }
-            m_session->MakeOffline(usedname);
-            // offline flavored game from here :3
-        }
-        case AuthSession::PlayableOnline:
-        {
-            launchInstance();
-            tryagain = false;
-            return;
-        }
         }
     }
     emitFailed(tr("Failed to launch."));
diff --git a/launcher/MainWindow.cpp b/launcher/MainWindow.cpp
index 9225193e..182b22e9 100644
--- a/launcher/MainWindow.cpp
+++ b/launcher/MainWindow.cpp
@@ -54,7 +54,7 @@
 #include <java/JavaUtils.h>
 #include <java/JavaInstallList.h>
 #include <launch/LaunchTask.h>
-#include <minecraft/auth/MojangAccountList.h>
+#include <minecraft/auth/AccountList.h>
 #include <SkinUtils.h>
 #include <BuildConfig.h>
 #include <net/NetJob.h>
@@ -90,6 +90,20 @@
 #include "KonamiCode.h"
 #include <InstanceCopyTask.h>
 
+namespace {
+QString profileInUseFilter(const QString & profile, bool used)
+{
+    if(used)
+    {
+        return QObject::tr("%1 (in use)").arg(profile);
+    }
+    else
+    {
+        return profile;
+    }
+}
+}
+
 // WHY: to hold the pre-translation strings together with the T pointer, so it can be retranslated without a lot of ugly code
 template <typename T>
 class Translated
@@ -753,49 +767,27 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new MainWindow
     // Update the menu when the active account changes.
     // Shouldn't have to use lambdas here like this, but if I don't, the compiler throws a fit.
     // Template hell sucks...
-    connect(MMC->accounts().get(), &MojangAccountList::activeAccountChanged, [this]
-            {
-                activeAccountChanged();
-            });
-    connect(MMC->accounts().get(), &MojangAccountList::listChanged, [this]
-            {
-                repopulateAccountsMenu();
-            });
+    connect(
+        MMC->accounts().get(),
+        &AccountList::activeAccountChanged,
+        [this] {
+            activeAccountChanged();
+        }
+    );
+    connect(
+        MMC->accounts().get(),
+        &AccountList::listChanged,
+        [this]
+        {
+            repopulateAccountsMenu();
+        }
+    );
 
     // Show initial account
     activeAccountChanged();
 
-    auto accounts = MMC->accounts();
-
-    QList<Net::Download::Ptr> skin_dls;
-    for (int i = 0; i < accounts->count(); i++)
-    {
-        auto account = accounts->at(i);
-        if (!account)
-        {
-            qWarning() << "Null account at index" << i;
-            continue;
-        }
-        for (auto profile : account->profiles())
-        {
-            auto meta = Env::getInstance().metacache()->resolveEntry("skins", profile.id + ".png");
-            auto action = Net::Download::makeCached(QUrl(BuildConfig.SKINS_BASE + profile.id + ".png"), meta);
-            skin_dls.append(action);
-            meta->setStale(true);
-        }
-    }
-    if (!skin_dls.isEmpty())
-    {
-        auto job = new NetJob("Startup player skins download");
-        connect(job, &NetJob::succeeded, this, &MainWindow::skinJobFinished);
-        connect(job, &NetJob::failed, this, &MainWindow::skinJobFinished);
-        for (auto action : skin_dls)
-        {
-            job->addNetAction(action);
-        }
-        skin_download_job.reset(job);
-        job->start();
-    }
+    // TODO: refresh accounts here?
+    // auto accounts = MMC->accounts();
 
     // load the news
     {
@@ -844,7 +836,15 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new MainWindow
 
 void MainWindow::retranslateUi()
 {
-    accountMenuButton->setText(tr("Profiles"));
+    std::shared_ptr<AccountList> accounts = MMC->accounts();
+    MinecraftAccountPtr active_account = accounts->activeAccount();
+    if(active_account) {
+        auto profileLabel = profileInUseFilter(active_account->profileName(), active_account->isInUse());
+        accountMenuButton->setText(profileLabel);
+    }
+    else {
+        accountMenuButton->setText(tr("Profiles"));
+    }
 
     if (m_selectedInstance) {
         m_statusLeft->setText(m_selectedInstance->getStatusbarDescription());
@@ -872,12 +872,6 @@ void MainWindow::konamiTriggered()
     qDebug() << "Super Secret Mode ACTIVATED!";
 }
 
-void MainWindow::skinJobFinished()
-{
-    activeAccountChanged();
-    skin_download_job.reset();
-}
-
 void MainWindow::showInstanceContextMenu(const QPoint &pos)
 {
     QList<QAction *> actions;
@@ -1018,34 +1012,21 @@ void MainWindow::updateToolsMenu()
     ui->actionLaunchInstanceOffline->setMenu(launchOfflineMenu);
 }
 
-QString profileInUseFilter(const QString & profile, bool used)
-{
-    if(used)
-    {
-        return profile + QObject::tr(" (in use)");
-    }
-    else
-    {
-        return profile;
-    }
-}
-
 void MainWindow::repopulateAccountsMenu()
 {
     accountMenu->clear();
 
-    std::shared_ptr<MojangAccountList> accounts = MMC->accounts();
-    MojangAccountPtr active_account = accounts->activeAccount();
+    std::shared_ptr<AccountList> accounts = MMC->accounts();
+    MinecraftAccountPtr active_account = accounts->activeAccount();
 
-    QString active_username = "";
+    QString active_profileId = "";
     if (active_account != nullptr)
     {
-        active_username = active_account->username();
-        const AccountProfile *profile = active_account->currentProfile();
+        active_profileId = active_account->profileId();
         // this can be called before accountMenuButton exists
-        if (profile != nullptr && accountMenuButton)
+        if (accountMenuButton)
         {
-            auto profileLabel = profileInUseFilter(profile->name, active_account->isInUse());
+            auto profileLabel = profileInUseFilter(active_account->profileName(), active_account->isInUse());
             accountMenuButton->setText(profileLabel);
         }
     }
@@ -1061,22 +1042,19 @@ void MainWindow::repopulateAccountsMenu()
         // TODO: Nicer way to iterate?
         for (int i = 0; i < accounts->count(); i++)
         {
-            MojangAccountPtr account = accounts->at(i);
-            for (auto profile : account->profiles())
+            MinecraftAccountPtr account = accounts->at(i);
+            auto profileLabel = profileInUseFilter(account->profileName(), account->isInUse());
+            QAction *action = new QAction(profileLabel, this);
+            action->setData(account->profileId());
+            action->setCheckable(true);
+            if (active_profileId == account->profileId())
             {
-                auto profileLabel = profileInUseFilter(profile.name, account->isInUse());
-                QAction *action = new QAction(profileLabel, this);
-                action->setData(account->username());
-                action->setCheckable(true);
-                if (active_username == account->username())
-                {
-                    action->setChecked(true);
-                }
-
-                action->setIcon(SkinUtils::getFaceFromCache(profile.id));
-                accountMenu->addAction(action);
-                connect(action, SIGNAL(triggered(bool)), SLOT(changeActiveAccount()));
+                action->setChecked(true);
             }
+
+            action->setIcon(account->getFace());
+            accountMenu->addAction(action);
+            connect(action, SIGNAL(triggered(bool)), SLOT(changeActiveAccount()));
         }
     }
 
@@ -1086,8 +1064,7 @@ void MainWindow::repopulateAccountsMenu()
     action->setCheckable(true);
     action->setIcon(MMC->getThemedIcon("noaccount"));
     action->setData("");
-    if (active_username.isEmpty())
-    {
+    if (active_profileId.isEmpty()) {
         action->setChecked(true);
     }
 
@@ -1134,18 +1111,15 @@ void MainWindow::activeAccountChanged()
 {
     repopulateAccountsMenu();
 
-    MojangAccountPtr account = MMC->accounts()->activeAccount();
+    MinecraftAccountPtr account = MMC->accounts()->activeAccount();
 
-    if (account != nullptr && account->username() != "")
+    // FIXME: this needs adjustment for MSA
+    if (account != nullptr && account->profileName() != "")
     {
-        const AccountProfile *profile = account->currentProfile();
-        if (profile != nullptr)
-        {
-            auto profileLabel = profileInUseFilter(profile->name, account->isInUse());
-            accountMenuButton->setIcon(SkinUtils::getFaceFromCache(profile->id));
-            accountMenuButton->setText(profileLabel);
-            return;
-        }
+        auto profileLabel = profileInUseFilter(account->profileName(), account->isInUse());
+        accountMenuButton->setText(profileLabel);
+        accountMenuButton->setIcon(account->getFace());
+        return;
     }
 
     // Set the icon to the "no account" icon.
diff --git a/launcher/MainWindow.h b/launcher/MainWindow.h
index c992ab94..67dec8cf 100644
--- a/launcher/MainWindow.h
+++ b/launcher/MainWindow.h
@@ -22,7 +22,7 @@
 #include <QTimer>
 
 #include "BaseInstance.h"
-#include "minecraft/auth/MojangAccount.h"
+#include "minecraft/auth/MinecraftAccount.h"
 #include "net/NetJob.h"
 #include "updater/GoUpdate.h"
 
@@ -149,8 +149,6 @@ private slots:
 
     void updateToolsMenu();
 
-    void skinJobFinished();
-
     void instanceActivated(QModelIndex);
 
     void instanceChanged(const QModelIndex &current, const QModelIndex &previous);
@@ -214,7 +212,6 @@ private:
     QToolButton *accountMenuButton = nullptr;
     KonamiCode * secretEventFilter = nullptr;
 
-    unique_qobject_ptr<NetJob> skin_download_job;
     unique_qobject_ptr<NewsChecker> m_newsChecker;
     unique_qobject_ptr<NotificationChecker> m_notificationChecker;
 
diff --git a/launcher/MultiMC.cpp b/launcher/MultiMC.cpp
index 932c7a76..5961a45d 100644
--- a/launcher/MultiMC.cpp
+++ b/launcher/MultiMC.cpp
@@ -42,7 +42,7 @@
 #include "dialogs/CustomMessageBox.h"
 #include "InstanceList.h"
 
-#include <minecraft/auth/MojangAccountList.h>
+#include <minecraft/auth/AccountList.h>
 #include "icons/IconList.h"
 #include "net/HttpMetaCache.h"
 #include "Env.h"
@@ -745,7 +745,7 @@ MultiMC::MultiMC(int &argc, char **argv) : QApplication(argc, argv)
 
     // and accounts
     {
-        m_accounts.reset(new MojangAccountList(this));
+        m_accounts.reset(new AccountList(this));
         qDebug() << "Loading accounts...";
         m_accounts->setListFilePath("accounts.json", true);
         m_accounts->loadList();
diff --git a/launcher/MultiMC.h b/launcher/MultiMC.h
index af2b41c1..59fd7345 100644
--- a/launcher/MultiMC.h
+++ b/launcher/MultiMC.h
@@ -24,7 +24,7 @@ class QFile;
 class HttpMetaCache;
 class SettingsObject;
 class InstanceList;
-class MojangAccountList;
+class AccountList;
 class IconList;
 class QNetworkAccessManager;
 class JavaInstallList;
@@ -111,7 +111,7 @@ public:
         return m_mcedit.get();
     }
 
-    std::shared_ptr<MojangAccountList> accounts() const
+    std::shared_ptr<AccountList> accounts() const
     {
         return m_accounts;
     }
@@ -188,7 +188,7 @@ private:
     FolderInstanceProvider * m_instanceFolder = nullptr;
     std::shared_ptr<IconList> m_icons;
     std::shared_ptr<UpdateChecker> m_updateChecker;
-    std::shared_ptr<MojangAccountList> m_accounts;
+    std::shared_ptr<AccountList> m_accounts;
     std::shared_ptr<JavaInstallList> m_javalist;
     std::shared_ptr<TranslationsModel> m_translations;
     std::shared_ptr<GenericPageProvider> m_globalSettingsProvider;
diff --git a/launcher/SkinUtils.cpp b/launcher/SkinUtils.cpp
index ec969889..a196173e 100644
--- a/launcher/SkinUtils.cpp
+++ b/launcher/SkinUtils.cpp
@@ -30,9 +30,7 @@ namespace SkinUtils
  */
 QPixmap getFaceFromCache(QString username, int height, int width)
 {
-    QFile fskin(ENV.metacache()
-                    ->resolveEntry("skins", username + ".png")
-                    ->getFullPath());
+    QFile fskin(ENV.metacache()->resolveEntry("skins", username + ".png")->getFullPath());
 
     if (fskin.exists())
     {
diff --git a/launcher/dialogs/LoginDialog.cpp b/launcher/dialogs/LoginDialog.cpp
index 32f8a48f..1dee9920 100644
--- a/launcher/dialogs/LoginDialog.cpp
+++ b/launcher/dialogs/LoginDialog.cpp
@@ -16,7 +16,7 @@
 #include "LoginDialog.h"
 #include "ui_LoginDialog.h"
 
-#include "minecraft/auth/YggdrasilTask.h"
+#include "minecraft/auth/AccountTask.h"
 
 #include <QtWidgets/QPushButton>
 
@@ -42,11 +42,10 @@ void LoginDialog::accept()
     ui->progressBar->setVisible(true);
 
     // Setup the login task and start it
-    m_account = MojangAccount::createFromUsername(ui->userTextBox->text());
+    m_account = MinecraftAccount::createFromUsername(ui->userTextBox->text());
     m_loginTask = m_account->login(nullptr, ui->passTextBox->text());
     connect(m_loginTask.get(), &Task::failed, this, &LoginDialog::onTaskFailed);
-    connect(m_loginTask.get(), &Task::succeeded, this,
-            &LoginDialog::onTaskSucceeded);
+    connect(m_loginTask.get(), &Task::succeeded, this, &LoginDialog::onTaskSucceeded);
     connect(m_loginTask.get(), &Task::status, this, &LoginDialog::onTaskStatus);
     connect(m_loginTask.get(), &Task::progress, this, &LoginDialog::onTaskProgress);
     m_loginTask->start();
@@ -98,7 +97,7 @@ void LoginDialog::onTaskProgress(qint64 current, qint64 total)
 }
 
 // Public interface
-MojangAccountPtr LoginDialog::newAccount(QWidget *parent, QString msg)
+MinecraftAccountPtr LoginDialog::newAccount(QWidget *parent, QString msg)
 {
     LoginDialog dlg(parent);
     dlg.ui->label->setText(msg);
diff --git a/launcher/dialogs/LoginDialog.h b/launcher/dialogs/LoginDialog.h
index 16bdddfb..13463640 100644
--- a/launcher/dialogs/LoginDialog.h
+++ b/launcher/dialogs/LoginDialog.h
@@ -18,7 +18,7 @@
 #include <QtWidgets/QDialog>
 #include <QtCore/QEventLoop>
 
-#include "minecraft/auth/MojangAccount.h"
+#include "minecraft/auth/MinecraftAccount.h"
 
 namespace Ui
 {
@@ -32,7 +32,7 @@ class LoginDialog : public QDialog
 public:
     ~LoginDialog();
 
-    static MojangAccountPtr newAccount(QWidget *parent, QString message);
+    static MinecraftAccountPtr newAccount(QWidget *parent, QString message);
 
 private:
     explicit LoginDialog(QWidget *parent = 0);
@@ -53,6 +53,6 @@ slots:
 
 private:
     Ui::LoginDialog *ui;
-    MojangAccountPtr m_account;
+    MinecraftAccountPtr m_account;
     std::shared_ptr<Task> m_loginTask;
 };
diff --git a/launcher/dialogs/LoginDialog.ui b/launcher/dialogs/LoginDialog.ui
index dbdb3b93..8fa4a45d 100644
--- a/launcher/dialogs/LoginDialog.ui
+++ b/launcher/dialogs/LoginDialog.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>421</width>
-    <height>238</height>
+    <height>198</height>
    </rect>
   </property>
   <property name="sizePolicy">
@@ -21,16 +21,6 @@
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
-    <widget class="QLabel" name="microsoftAccountsNoticeLabel">
-     <property name="text">
-      <string>NOTICE: MultiMC does not currently support Microsoft accounts. This means that accounts created from December 2020 onwards cannot be used.</string>
-     </property>
-     <property name="wordWrap">
-      <bool>true</bool>
-     </property>
-    </widget>
-   </item>
-   <item>
     <widget class="QLabel" name="label">
      <property name="text">
       <string notr="true">Message label placeholder.</string>
diff --git a/launcher/dialogs/MSALoginDialog.cpp b/launcher/dialogs/MSALoginDialog.cpp
new file mode 100644
index 00000000..778b379d
--- /dev/null
+++ b/launcher/dialogs/MSALoginDialog.cpp
@@ -0,0 +1,96 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MSALoginDialog.h"
+#include "ui_MSALoginDialog.h"
+
+#include "minecraft/auth/AccountTask.h"
+
+#include <QtWidgets/QPushButton>
+
+MSALoginDialog::MSALoginDialog(QWidget *parent) : QDialog(parent), ui(new Ui::MSALoginDialog)
+{
+    ui->setupUi(this);
+    ui->progressBar->setVisible(false);
+    // ui->buttonBox->button(QDialogButtonBox::Cancel)->setEnabled(false);
+
+    connect(ui->buttonBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
+    connect(ui->buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);
+}
+
+int MSALoginDialog::exec() {
+    setUserInputsEnabled(false);
+    ui->progressBar->setVisible(true);
+
+    // Setup the login task and start it
+    m_account = MinecraftAccount::createBlankMSA();
+    m_loginTask = m_account->loginMSA(nullptr);
+    connect(m_loginTask.get(), &Task::failed, this, &MSALoginDialog::onTaskFailed);
+    connect(m_loginTask.get(), &Task::succeeded, this, &MSALoginDialog::onTaskSucceeded);
+    connect(m_loginTask.get(), &Task::status, this, &MSALoginDialog::onTaskStatus);
+    connect(m_loginTask.get(), &Task::progress, this, &MSALoginDialog::onTaskProgress);
+    m_loginTask->start();
+
+    return QDialog::exec();
+}
+
+
+MSALoginDialog::~MSALoginDialog()
+{
+    delete ui;
+}
+
+void MSALoginDialog::setUserInputsEnabled(bool enable)
+{
+    ui->buttonBox->setEnabled(enable);
+}
+
+void MSALoginDialog::onTaskFailed(const QString &reason)
+{
+    // Set message
+    ui->label->setText("<span style='color:red'>" + reason + "</span>");
+
+    // Re-enable user-interaction
+    setUserInputsEnabled(true);
+    ui->progressBar->setVisible(false);
+}
+
+void MSALoginDialog::onTaskSucceeded()
+{
+    QDialog::accept();
+}
+
+void MSALoginDialog::onTaskStatus(const QString &status)
+{
+    ui->label->setText(status);
+}
+
+void MSALoginDialog::onTaskProgress(qint64 current, qint64 total)
+{
+    ui->progressBar->setMaximum(total);
+    ui->progressBar->setValue(current);
+}
+
+// Public interface
+MinecraftAccountPtr MSALoginDialog::newAccount(QWidget *parent, QString msg)
+{
+    MSALoginDialog dlg(parent);
+    dlg.ui->label->setText(msg);
+    if (dlg.exec() == QDialog::Accepted)
+    {
+        return dlg.m_account;
+    }
+    return 0;
+}
diff --git a/launcher/dialogs/MSALoginDialog.h b/launcher/dialogs/MSALoginDialog.h
new file mode 100644
index 00000000..402180ee
--- /dev/null
+++ b/launcher/dialogs/MSALoginDialog.h
@@ -0,0 +1,55 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QtWidgets/QDialog>
+#include <QtCore/QEventLoop>
+
+#include "minecraft/auth/MinecraftAccount.h"
+
+namespace Ui
+{
+class MSALoginDialog;
+}
+
+class MSALoginDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    ~MSALoginDialog();
+
+    static MinecraftAccountPtr newAccount(QWidget *parent, QString message);
+    int exec() override;
+
+private:
+    explicit MSALoginDialog(QWidget *parent = 0);
+
+    void setUserInputsEnabled(bool enable);
+
+protected
+slots:
+    void onTaskFailed(const QString &reason);
+    void onTaskSucceeded();
+    void onTaskStatus(const QString &status);
+    void onTaskProgress(qint64 current, qint64 total);
+
+private:
+    Ui::MSALoginDialog *ui;
+    MinecraftAccountPtr m_account;
+    std::shared_ptr<Task> m_loginTask;
+};
+
diff --git a/launcher/dialogs/MSALoginDialog.ui b/launcher/dialogs/MSALoginDialog.ui
new file mode 100644
index 00000000..4ae8085a
--- /dev/null
+++ b/launcher/dialogs/MSALoginDialog.ui
@@ -0,0 +1,60 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MSALoginDialog</class>
+ <widget class="QDialog" name="MSALoginDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>421</width>
+    <height>114</height>
+   </rect>
+  </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+    <horstretch>0</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
+  <property name="windowTitle">
+   <string>Add Microsoft Account</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QLabel" name="label">
+     <property name="text">
+      <string notr="true">Message label placeholder.</string>
+     </property>
+     <property name="textFormat">
+      <enum>Qt::RichText</enum>
+     </property>
+     <property name="textInteractionFlags">
+      <set>Qt::LinksAccessibleByKeyboard|Qt::LinksAccessibleByMouse|Qt::TextBrowserInteraction|Qt::TextSelectableByKeyboard|Qt::TextSelectableByMouse</set>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QProgressBar" name="progressBar">
+     <property name="value">
+      <number>24</number>
+     </property>
+     <property name="textVisible">
+      <bool>false</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/launcher/dialogs/ProfileSelectDialog.cpp b/launcher/dialogs/ProfileSelectDialog.cpp
index ae34709f..e2ad73e4 100644
--- a/launcher/dialogs/ProfileSelectDialog.cpp
+++ b/launcher/dialogs/ProfileSelectDialog.cpp
@@ -33,9 +33,10 @@ ProfileSelectDialog::ProfileSelectDialog(const QString &message, int flags, QWid
     m_accounts = MMC->accounts();
     auto view = ui->listView;
     //view->setModel(m_accounts.get());
-    //view->hideColumn(MojangAccountList::ActiveColumn);
+    //view->hideColumn(AccountList::ActiveColumn);
     view->setColumnCount(1);
     view->setRootIsDecorated(false);
+    // FIXME: use a real model, not this
     if(QTreeWidgetItem* header = view->headerItem())
     {
         header->setText(0, tr("Name"));
@@ -47,20 +48,19 @@ ProfileSelectDialog::ProfileSelectDialog(const QString &message, int flags, QWid
     QList <QTreeWidgetItem *> items;
     for (int i = 0; i < m_accounts->count(); i++)
     {
-        MojangAccountPtr account = m_accounts->at(i);
-        for (auto profile : account->profiles())
-        {
-            auto profileLabel = profile.name;
-            if(account->isInUse())
-            {
-                profileLabel += tr(" (in use)");
-            }
-            auto item = new QTreeWidgetItem(view);
-            item->setText(0, profileLabel);
-            item->setIcon(0, SkinUtils::getFaceFromCache(profile.id));
-            item->setData(0, MojangAccountList::PointerRole, QVariant::fromValue(account));
-            items.append(item);
+        MinecraftAccountPtr account = m_accounts->at(i);
+        QString profileLabel;
+        if(account->isInUse()) {
+            profileLabel = tr("%1 (in use)").arg(account->profileName());
         }
+        else {
+            profileLabel = account->profileName();
+        }
+        auto item = new QTreeWidgetItem(view);
+        item->setText(0, profileLabel);
+        item->setIcon(0, account->getFace());
+        item->setData(0, AccountList::PointerRole, QVariant::fromValue(account));
+        items.append(item);
     }
     view->addTopLevelItems(items);
 
@@ -84,7 +84,7 @@ ProfileSelectDialog::~ProfileSelectDialog()
     delete ui;
 }
 
-MojangAccountPtr ProfileSelectDialog::selectedAccount() const
+MinecraftAccountPtr ProfileSelectDialog::selectedAccount() const
 {
     return m_selected;
 }
@@ -105,7 +105,7 @@ void ProfileSelectDialog::on_buttonBox_accepted()
     if (selection.size() > 0)
     {
         QModelIndex selected = selection.first();
-        m_selected = selected.data(MojangAccountList::PointerRole).value<MojangAccountPtr>();
+        m_selected = selected.data(AccountList::PointerRole).value<MinecraftAccountPtr>();
     }
     close();
 }
diff --git a/launcher/dialogs/ProfileSelectDialog.h b/launcher/dialogs/ProfileSelectDialog.h
index 9f95830c..a4acd9a1 100644
--- a/launcher/dialogs/ProfileSelectDialog.h
+++ b/launcher/dialogs/ProfileSelectDialog.h
@@ -19,7 +19,7 @@
 
 #include <memory>
 
-#include "minecraft/auth/MojangAccountList.h"
+#include "minecraft/auth/AccountList.h"
 
 namespace Ui
 {
@@ -59,7 +59,7 @@ public:
      * Gets a pointer to the account that the user selected.
      * This is null if the user clicked cancel or hasn't clicked OK yet.
      */
-    MojangAccountPtr selectedAccount() const;
+    MinecraftAccountPtr selectedAccount() const;
 
     /*!
      * Returns true if the user checked the "use as global default" checkbox.
@@ -80,10 +80,10 @@ slots:
     void on_buttonBox_rejected();
 
 protected:
-    std::shared_ptr<MojangAccountList> m_accounts;
+    std::shared_ptr<AccountList> m_accounts;
 
     //! The account that was selected when the user clicked OK.
-    MojangAccountPtr m_selected;
+    MinecraftAccountPtr m_selected;
 
 private:
     Ui::ProfileSelectDialog *ui;
diff --git a/launcher/dialogs/SkinUploadDialog.cpp b/launcher/dialogs/SkinUploadDialog.cpp
index 56133529..3c62edac 100644
--- a/launcher/dialogs/SkinUploadDialog.cpp
+++ b/launcher/dialogs/SkinUploadDialog.cpp
@@ -107,7 +107,7 @@ void SkinUploadDialog::on_skinBrowseBtn_clicked()
     ui->skinPathTextBox->setText(cooked_path);
 }
 
-SkinUploadDialog::SkinUploadDialog(MojangAccountPtr acct, QWidget *parent)
+SkinUploadDialog::SkinUploadDialog(MinecraftAccountPtr acct, QWidget *parent)
     :QDialog(parent), m_acct(acct), ui(new Ui::SkinUploadDialog)
 {
     ui->setupUi(this);
diff --git a/launcher/dialogs/SkinUploadDialog.h b/launcher/dialogs/SkinUploadDialog.h
index deb44eac..84d17dc6 100644
--- a/launcher/dialogs/SkinUploadDialog.h
+++ b/launcher/dialogs/SkinUploadDialog.h
@@ -1,7 +1,7 @@
 #pragma once
 
 #include <QDialog>
-#include <minecraft/auth/MojangAccount.h>
+#include <minecraft/auth/MinecraftAccount.h>
 
 namespace Ui
 {
@@ -11,7 +11,7 @@ namespace Ui
 class SkinUploadDialog : public QDialog {
     Q_OBJECT
 public:
-    explicit SkinUploadDialog(MojangAccountPtr acct, QWidget *parent = 0);
+    explicit SkinUploadDialog(MinecraftAccountPtr acct, QWidget *parent = 0);
     virtual ~SkinUploadDialog() {};
 
 public slots:
@@ -22,7 +22,7 @@ public slots:
     void on_skinBrowseBtn_clicked();
 
 protected:
-    MojangAccountPtr m_acct;
+    MinecraftAccountPtr m_acct;
 
 private:
     Ui::SkinUploadDialog *ui;
diff --git a/launcher/minecraft/MinecraftInstance.cpp b/launcher/minecraft/MinecraftInstance.cpp
index dbf9f816..5f3c7244 100644
--- a/launcher/minecraft/MinecraftInstance.cpp
+++ b/launcher/minecraft/MinecraftInstance.cpp
@@ -423,7 +423,7 @@ QStringList MinecraftInstance::processMinecraftArgs(
     // yggdrasil!
     if(session)
     {
-        token_mapping["auth_username"] = session->username;
+        // token_mapping["auth_username"] = session->username;
         token_mapping["auth_session"] = session->session;
         token_mapping["auth_access_token"] = session->access_token;
         token_mapping["auth_player_name"] = session->player_name;
@@ -691,19 +691,11 @@ QMap<QString, QString> MinecraftInstance::createCensorFilterFromSession(AuthSess
         addToFilter(sessionRef.session, tr("<SESSION ID>"));
     }
     addToFilter(sessionRef.access_token, tr("<ACCESS TOKEN>"));
-    addToFilter(sessionRef.client_token, tr("<CLIENT TOKEN>"));
+    if(sessionRef.client_token.size()) {
+        addToFilter(sessionRef.client_token, tr("<CLIENT TOKEN>"));
+    }
     addToFilter(sessionRef.uuid, tr("<PROFILE ID>"));
 
-    auto i = sessionRef.u.properties.begin();
-    while (i != sessionRef.u.properties.end())
-    {
-        if(i.value().length() <= 3) {
-            ++i;
-            continue;
-        }
-        addToFilter(i.value(), "<" + i.key().toUpper() + ">");
-        ++i;
-    }
     return filter;
 }
 
diff --git a/launcher/minecraft/auth-msa/BuildConfig.cpp.in b/launcher/minecraft/auth-msa/BuildConfig.cpp.in
deleted file mode 100644
index 8f470e25..00000000
--- a/launcher/minecraft/auth-msa/BuildConfig.cpp.in
+++ /dev/null
@@ -1,9 +0,0 @@
-#include "BuildConfig.h"
-#include <QObject>
-
-const Config BuildConfig;
-
-Config::Config()
-{
-    CLIENT_ID = "@MOJANGDEMO_CLIENT_ID@";
-}
diff --git a/launcher/minecraft/auth-msa/BuildConfig.h b/launcher/minecraft/auth-msa/BuildConfig.h
deleted file mode 100644
index 7a01d704..00000000
--- a/launcher/minecraft/auth-msa/BuildConfig.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#pragma once
-#include <QString>
-
-class Config
-{
-public:
-    Config();
-    QString CLIENT_ID;
-};
-
-extern const Config BuildConfig;
diff --git a/launcher/minecraft/auth-msa/CMakeLists.txt b/launcher/minecraft/auth-msa/CMakeLists.txt
deleted file mode 100644
index 22777d1b..00000000
--- a/launcher/minecraft/auth-msa/CMakeLists.txt
+++ /dev/null
@@ -1,28 +0,0 @@
-find_package(Qt5 COMPONENTS Core Gui Network Widgets REQUIRED)
-
-set(CMAKE_AUTOMOC ON)
-set(CMAKE_AUTOUIC ON)
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
-
-
-set(MOJANGDEMO_CLIENT_ID "" CACHE STRING "Client ID used for OAuth2 in mojangdemo")
-
-configure_file("${CMAKE_CURRENT_SOURCE_DIR}/BuildConfig.cpp.in" "${CMAKE_CURRENT_BINARY_DIR}/BuildConfig.cpp")
-
-set(mojang_SRCS
-    main.cpp
-    context.cpp
-    context.h
-
-    mainwindow.cpp
-    mainwindow.h
-    mainwindow.ui
-
-    ${CMAKE_CURRENT_BINARY_DIR}/BuildConfig.cpp
-    BuildConfig.h
-)
-
-add_executable( mojangdemo ${mojang_SRCS} )
-target_link_libraries( mojangdemo Katabasis Qt5::Gui Qt5::Widgets )
-target_include_directories(mojangdemo PRIVATE logic)
diff --git a/launcher/minecraft/auth-msa/main.cpp b/launcher/minecraft/auth-msa/main.cpp
deleted file mode 100644
index 481e0126..00000000
--- a/launcher/minecraft/auth-msa/main.cpp
+++ /dev/null
@@ -1,100 +0,0 @@
-#include <QApplication>
-#include <QStringList>
-#include <QTimer>
-#include <QDebug>
-#include <QFile>
-#include <QSaveFile>
-
-#include "context.h"
-#include "mainwindow.h"
-
-void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
-{
-    QByteArray localMsg = msg.toLocal8Bit();
-    const char *file = context.file ? context.file : "";
-    const char *function = context.function ? context.function : "";
-    switch (type) {
-    case QtDebugMsg:
-        fprintf(stderr, "Debug: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
-        break;
-    case QtInfoMsg:
-        fprintf(stderr, "Info: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
-        break;
-    case QtWarningMsg:
-        fprintf(stderr, "Warning: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
-        break;
-    case QtCriticalMsg:
-        fprintf(stderr, "Critical: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
-        break;
-    case QtFatalMsg:
-        fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
-        break;
-    }
-}
-
-class Helper : public QObject {
-    Q_OBJECT
-
-public:
-    Helper(Context * context) : QObject(), context_(context), msg_(QString()) {
-        QFile tokenCache("usercache.dat");
-        if(tokenCache.open(QIODevice::ReadOnly)) {
-            context_->resumeFromState(tokenCache.readAll());
-        }
-    }
-
-public slots:
-    void run() {
-        connect(context_, &Context::activityChanged, this, &Helper::onActivityChanged);
-        context_->silentSignIn();
-    }
-
-    void onFailed() {
-        qDebug() << "Login failed";
-    }
-
-    void onActivityChanged(Katabasis::Activity activity) {
-        if(activity == Katabasis::Activity::Idle) {
-            switch(context_->validity()) {
-                case Katabasis::Validity::None: {
-                    // account is gone, remove it.
-                    QFile::remove("usercache.dat");
-                }
-                break;
-                case Katabasis::Validity::Assumed: {
-                    // this is basically a soft-failed refresh. do nothing.
-                }
-                break;
-                case Katabasis::Validity::Certain: {
-                    // stuff got refreshed / signed in. Save.
-                    auto data = context_->saveState();
-                    QSaveFile tokenCache("usercache.dat");
-                    if(tokenCache.open(QIODevice::WriteOnly)) {
-                        tokenCache.write(context_->saveState());
-                        tokenCache.commit();
-                    }
-                }
-                break;
-            }
-        }
-    }
-
-private:
-    Context *context_;
-    QString msg_;
-};
-
-int main(int argc, char *argv[]) {
-    qInstallMessageHandler(myMessageOutput);
-    QApplication a(argc, argv);
-    QCoreApplication::setOrganizationName("MultiMC");
-    QCoreApplication::setApplicationName("MultiMC");
-    Context c;
-    Helper helper(&c);
-    MainWindow window(&c);
-    window.show();
-    QTimer::singleShot(0, &helper, &Helper::run);
-    return a.exec();
-}
-
-#include "main.moc"
diff --git a/launcher/minecraft/auth-msa/mainwindow.cpp b/launcher/minecraft/auth-msa/mainwindow.cpp
deleted file mode 100644
index d4e18dc0..00000000
--- a/launcher/minecraft/auth-msa/mainwindow.cpp
+++ /dev/null
@@ -1,97 +0,0 @@
-#include "mainwindow.h"
-#include "ui_mainwindow.h"
-#include <QDebug>
-
-#include <QDesktopServices>
-
-#include "BuildConfig.h"
-
-MainWindow::MainWindow(Context * context, QWidget *parent) :
-    QMainWindow(parent),
-    m_context(context),
-    m_ui(new Ui::MainWindow)
-{
-    m_ui->setupUi(this);
-    connect(m_ui->signInButton_MSA, &QPushButton::clicked, this, &MainWindow::SignInMSAClicked);
-    connect(m_ui->signInButton_Mojang, &QPushButton::clicked, this, &MainWindow::SignInMojangClicked);
-    connect(m_ui->signOutButton, &QPushButton::clicked, this, &MainWindow::SignOutClicked);
-    connect(m_ui->refreshButton, &QPushButton::clicked, this, &MainWindow::RefreshClicked);
-
-    // connect(m_context, &Context::linkingSucceeded, this, &MainWindow::SignInSucceeded);
-    // connect(m_context, &Context::linkingFailed, this, &MainWindow::SignInFailed);
-    connect(m_context, &Context::activityChanged, this, &MainWindow::ActivityChanged);
-    ActivityChanged(Katabasis::Activity::Idle);
-}
-
-MainWindow::~MainWindow() = default;
-
-void MainWindow::ActivityChanged(Katabasis::Activity activity) {
-    switch(activity) {
-        case Katabasis::Activity::Idle: {
-            if(m_context->validity() != Katabasis::Validity::None) {
-                m_ui->signInButton_Mojang->setEnabled(false);
-                m_ui->signInButton_MSA->setEnabled(false);
-                m_ui->signOutButton->setEnabled(true);
-                m_ui->refreshButton->setEnabled(true);
-                m_ui->statusBar->showMessage(QString("Hello %1!").arg(m_context->userName()));
-            }
-            else {
-                m_ui->signInButton_Mojang->setEnabled(true);
-                m_ui->signInButton_MSA->setEnabled(true);
-                m_ui->signOutButton->setEnabled(false);
-                m_ui->refreshButton->setEnabled(false);
-                m_ui->statusBar->showMessage("Press the login button to start.");
-            }
-        }
-        break;
-        case Katabasis::Activity::LoggingIn: {
-            m_ui->signInButton_Mojang->setEnabled(false);
-            m_ui->signInButton_MSA->setEnabled(false);
-            m_ui->signOutButton->setEnabled(false);
-            m_ui->refreshButton->setEnabled(false);
-            m_ui->statusBar->showMessage("Logging in...");
-        }
-        break;
-        case Katabasis::Activity::LoggingOut: {
-            m_ui->signInButton_Mojang->setEnabled(false);
-            m_ui->signInButton_MSA->setEnabled(false);
-            m_ui->signOutButton->setEnabled(false);
-            m_ui->refreshButton->setEnabled(false);
-            m_ui->statusBar->showMessage("Logging out...");
-        }
-        break;
-        case Katabasis::Activity::Refreshing: {
-            m_ui->signInButton_Mojang->setEnabled(false);
-            m_ui->signInButton_MSA->setEnabled(false);
-            m_ui->signOutButton->setEnabled(false);
-            m_ui->refreshButton->setEnabled(false);
-            m_ui->statusBar->showMessage("Refreshing login...");
-        }
-        break;
-    }
-}
-
-void MainWindow::SignInMSAClicked() {
-    qDebug() << "Sign In MSA";
-    // signIn({{"prompt",  "select_account"}})
-    // FIXME: wrong. very wrong. this should not be operating on the current context
-    m_context->signIn();
-}
-
-void MainWindow::SignInMojangClicked() {
-    qDebug() << "Sign In Mojang";
-    // signIn({{"prompt",  "select_account"}})
-    // FIXME: wrong. very wrong. this should not be operating on the current context
-    m_context->signIn();
-}
-
-
-void MainWindow::SignOutClicked() {
-    qDebug() << "Sign Out";
-    m_context->signOut();
-}
-
-void MainWindow::RefreshClicked() {
-    qDebug() << "Refresh";
-    m_context->silentSignIn();
-}
diff --git a/launcher/minecraft/auth-msa/mainwindow.h b/launcher/minecraft/auth-msa/mainwindow.h
deleted file mode 100644
index abde52d8..00000000
--- a/launcher/minecraft/auth-msa/mainwindow.h
+++ /dev/null
@@ -1,34 +0,0 @@
-#pragma once
-
-#include <QMainWindow>
-#include <QScopedPointer>
-#include <QtNetwork>
-#include <katabasis/Bits.h>
-
-#include "context.h"
-
-namespace Ui {
-class MainWindow;
-}
-
-class MainWindow : public QMainWindow {
-    Q_OBJECT
-
-public:
-    explicit MainWindow(Context * context, QWidget *parent = nullptr);
-    ~MainWindow() override;
-
-private slots:
-    void SignInMojangClicked();
-    void SignInMSAClicked();
-
-    void SignOutClicked();
-    void RefreshClicked();
-
-    void ActivityChanged(Katabasis::Activity activity);
-
-private:
-    Context* m_context;
-    QScopedPointer<Ui::MainWindow> m_ui;
-};
-
diff --git a/launcher/minecraft/auth-msa/mainwindow.ui b/launcher/minecraft/auth-msa/mainwindow.ui
deleted file mode 100644
index 32b34128..00000000
--- a/launcher/minecraft/auth-msa/mainwindow.ui
+++ /dev/null
@@ -1,72 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ui version="4.0">
- <class>MainWindow</class>
- <widget class="QMainWindow" name="MainWindow">
-  <property name="geometry">
-   <rect>
-    <x>0</x>
-    <y>0</y>
-    <width>1037</width>
-    <height>511</height>
-   </rect>
-  </property>
-  <property name="windowTitle">
-   <string>SmartMapsClient</string>
-  </property>
-  <property name="dockNestingEnabled">
-   <bool>true</bool>
-  </property>
-  <widget class="QWidget" name="centralWidget">
-   <layout class="QGridLayout" name="gridLayout">
-    <item row="1" column="3">
-     <widget class="QPushButton" name="signInButton_Mojang">
-      <property name="text">
-       <string>SignIn Mojang</string>
-      </property>
-     </widget>
-    </item>
-    <item row="3" column="3">
-     <widget class="Line" name="line">
-      <property name="orientation">
-       <enum>Qt::Horizontal</enum>
-      </property>
-     </widget>
-    </item>
-    <item row="1" column="0" rowspan="7" colspan="3">
-     <widget class="QTreeView" name="accountView"/>
-    </item>
-    <item row="5" column="3">
-     <widget class="QPushButton" name="refreshButton">
-      <property name="text">
-       <string>Refresh</string>
-      </property>
-     </widget>
-    </item>
-    <item row="2" column="3">
-     <widget class="QPushButton" name="signInButton_MSA">
-      <property name="text">
-       <string>SignIn MSA</string>
-      </property>
-     </widget>
-    </item>
-    <item row="6" column="3">
-     <widget class="QPushButton" name="signOutButton">
-      <property name="text">
-       <string>SignOut</string>
-      </property>
-     </widget>
-    </item>
-    <item row="4" column="3">
-     <widget class="QPushButton" name="makeActiveButton">
-      <property name="text">
-       <string>Make Active</string>
-      </property>
-     </widget>
-    </item>
-   </layout>
-  </widget>
-  <widget class="QStatusBar" name="statusBar"/>
- </widget>
- <resources/>
- <connections/>
-</ui>
diff --git a/launcher/minecraft/auth/AccountData.cpp b/launcher/minecraft/auth/AccountData.cpp
new file mode 100644
index 00000000..77c73c1b
--- /dev/null
+++ b/launcher/minecraft/auth/AccountData.cpp
@@ -0,0 +1,387 @@
+#include "AccountData.h"
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QDebug>
+#include <QUuid>
+
+namespace {
+void tokenToJSONV3(QJsonObject &parent, Katabasis::Token t, const char * tokenName) {
+    if(!t.persistent) {
+        return;
+    }
+    QJsonObject out;
+    if(t.issueInstant.isValid()) {
+        out["iat"] = QJsonValue(t.issueInstant.toMSecsSinceEpoch() / 1000);
+    }
+
+    if(t.notAfter.isValid()) {
+        out["exp"] = QJsonValue(t.notAfter.toMSecsSinceEpoch() / 1000);
+    }
+
+    bool save = false;
+    if(!t.token.isEmpty()) {
+        out["token"] = QJsonValue(t.token);
+        save = true;
+    }
+    if(!t.refresh_token.isEmpty()) {
+        out["refresh_token"] = QJsonValue(t.refresh_token);
+        save = true;
+    }
+    if(t.extra.size()) {
+        out["extra"] = QJsonObject::fromVariantMap(t.extra);
+        save = true;
+    }
+    if(save) {
+        parent[tokenName] = out;
+    }
+}
+
+Katabasis::Token tokenFromJSONV3(const QJsonObject &parent, const char * tokenName) {
+    Katabasis::Token out;
+    auto tokenObject = parent.value(tokenName).toObject();
+    if(tokenObject.isEmpty()) {
+        return out;
+    }
+    auto issueInstant = tokenObject.value("iat");
+    if(issueInstant.isDouble()) {
+        out.issueInstant = QDateTime::fromMSecsSinceEpoch(((int64_t) issueInstant.toDouble()) * 1000);
+    }
+
+    auto notAfter = tokenObject.value("exp");
+    if(notAfter.isDouble()) {
+        out.notAfter = QDateTime::fromMSecsSinceEpoch(((int64_t) notAfter.toDouble()) * 1000);
+    }
+
+    auto token = tokenObject.value("token");
+    if(token.isString()) {
+        out.token = token.toString();
+        out.validity = Katabasis::Validity::Assumed;
+    }
+
+    auto refresh_token = tokenObject.value("refresh_token");
+    if(refresh_token.isString()) {
+        out.refresh_token = refresh_token.toString();
+    }
+
+    auto extra = tokenObject.value("extra");
+    if(extra.isObject()) {
+        out.extra = extra.toObject().toVariantMap();
+    }
+    return out;
+}
+
+void profileToJSONV3(QJsonObject &parent, MinecraftProfile p, const char * tokenName) {
+    if(p.id.isEmpty()) {
+        return;
+    }
+    QJsonObject out;
+    out["id"] = QJsonValue(p.id);
+    out["name"] = QJsonValue(p.name);
+    if(p.currentCape != -1) {
+        out["cape"] = p.capes[p.currentCape].id;
+    }
+
+    {
+        QJsonObject skinObj;
+        skinObj["id"] = p.skin.id;
+        skinObj["url"] = p.skin.url;
+        skinObj["variant"] = p.skin.variant;
+        if(p.skin.data.size()) {
+            skinObj["data"] = QString::fromLatin1(p.skin.data.toBase64());
+        }
+        out["skin"] = skinObj;
+    }
+
+    QJsonArray capesArray;
+    for(auto & cape: p.capes) {
+        QJsonObject capeObj;
+        capeObj["id"] = cape.id;
+        capeObj["url"] = cape.url;
+        capeObj["alias"] = cape.alias;
+        if(cape.data.size()) {
+            capeObj["data"] = QString::fromLatin1(cape.data.toBase64());
+        }
+        capesArray.push_back(capeObj);
+    }
+    out["capes"] = capesArray;
+    parent[tokenName] = out;
+}
+
+MinecraftProfile profileFromJSONV3(const QJsonObject &parent, const char * tokenName) {
+    MinecraftProfile out;
+    auto tokenObject = parent.value(tokenName).toObject();
+    if(tokenObject.isEmpty()) {
+        return out;
+    }
+    {
+        auto idV = tokenObject.value("id");
+        auto nameV = tokenObject.value("name");
+        if(!idV.isString() || !nameV.isString()) {
+            qWarning() << "mandatory profile attributes are missing or of unexpected type";
+            return MinecraftProfile();
+        }
+        out.name = nameV.toString();
+        out.id = idV.toString();
+    }
+
+    {
+        auto skinV = tokenObject.value("skin");
+        if(!skinV.isObject()) {
+            qWarning() << "skin is missing";
+            return MinecraftProfile();
+        }
+        auto skinObj = skinV.toObject();
+        auto idV = skinObj.value("id");
+        auto urlV = skinObj.value("url");
+        auto variantV = skinObj.value("variant");
+        if(!idV.isString() || !urlV.isString() || !variantV.isString()) {
+            qWarning() << "mandatory skin attributes are missing or of unexpected type";
+            return MinecraftProfile();
+        }
+        out.skin.id = idV.toString();
+        out.skin.url = urlV.toString();
+        out.skin.variant = variantV.toString();
+
+        // data for skin is optional
+        auto dataV = skinObj.value("data");
+        if(dataV.isString()) {
+            // TODO: validate base64
+            out.skin.data = QByteArray::fromBase64(dataV.toString().toLatin1());
+        }
+        else if (!dataV.isUndefined()) {
+            qWarning() << "skin data is something unexpected";
+            return MinecraftProfile();
+        }
+    }
+
+    auto capesV = tokenObject.value("capes");
+    if(!capesV.isArray()) {
+        qWarning() << "capes is not an array!";
+        return MinecraftProfile();
+    }
+    auto capesArray = capesV.toArray();
+    for(auto capeV: capesArray) {
+        if(!capeV.isObject()) {
+            qWarning() << "cape is not an object!";
+            return MinecraftProfile();
+        }
+        auto capeObj = capeV.toObject();
+        auto idV = capeObj.value("id");
+        auto urlV = capeObj.value("url");
+        auto aliasV = capeObj.value("alias");
+        if(!idV.isString() || !urlV.isString() || !aliasV.isString()) {
+            qWarning() << "mandatory skin attributes are missing or of unexpected type";
+            return MinecraftProfile();
+        }
+        Cape cape;
+        cape.id = idV.toString();
+        cape.url = urlV.toString();
+        cape.alias = aliasV.toString();
+
+        // data for cape is optional.
+        auto dataV = capeObj.value("data");
+        if(dataV.isString()) {
+            // TODO: validate base64
+            cape.data = QByteArray::fromBase64(dataV.toString().toLatin1());
+        }
+        else if (!dataV.isUndefined()) {
+            qWarning() << "cape data is something unexpected";
+            return MinecraftProfile();
+        }
+        out.capes.push_back(cape);
+    }
+    out.validity = Katabasis::Validity::Assumed;
+    return out;
+}
+
+}
+
+bool AccountData::resumeStateFromV2(QJsonObject data) {
+    // The JSON object must at least have a username for it to be valid.
+    if (!data.value("username").isString())
+    {
+        qCritical() << "Can't load Mojang account info from JSON object. Username field is missing or of the wrong type.";
+        return false;
+    }
+
+    QString userName = data.value("username").toString("");
+    QString clientToken = data.value("clientToken").toString("");
+    QString accessToken = data.value("accessToken").toString("");
+
+    QJsonArray profileArray = data.value("profiles").toArray();
+    if (profileArray.size() < 1)
+    {
+        qCritical() << "Can't load Mojang account with username \"" << userName << "\". No profiles found.";
+        return false;
+    }
+
+    struct AccountProfile
+    {
+        QString id;
+        QString name;
+        bool legacy;
+    };
+
+    QList<AccountProfile> profiles;
+    int currentProfileIndex = 0;
+    int index = -1;
+    QString currentProfile = data.value("activeProfile").toString("");
+    for (QJsonValue profileVal : profileArray)
+    {
+        index++;
+        QJsonObject profileObject = profileVal.toObject();
+        QString id = profileObject.value("id").toString("");
+        QString name = profileObject.value("name").toString("");
+        bool legacy = profileObject.value("legacy").toBool(false);
+        if (id.isEmpty() || name.isEmpty())
+        {
+            qWarning() << "Unable to load a profile" << name << "because it was missing an ID or a name.";
+            continue;
+        }
+        if(id == currentProfile) {
+            currentProfileIndex = index;
+        }
+        profiles.append({id, name, legacy});
+    }
+    auto & profile = profiles[currentProfileIndex];
+
+    type = AccountType::Mojang;
+    legacy = profile.legacy;
+
+    minecraftProfile.id = profile.id;
+    minecraftProfile.name = profile.name;
+    minecraftProfile.validity = Katabasis::Validity::Assumed;
+
+    yggdrasilToken.token = accessToken;
+    yggdrasilToken.extra["clientToken"] = clientToken;
+    yggdrasilToken.extra["userName"] = userName;
+    yggdrasilToken.validity = Katabasis::Validity::Assumed;
+
+    validity_ = minecraftProfile.validity;
+    return true;
+}
+
+bool AccountData::resumeStateFromV3(QJsonObject data) {
+    auto typeV = data.value("type");
+    if(!typeV.isString()) {
+        qWarning() << "Failed to parse account data: type is missing.";
+        return false;
+    }
+    auto typeS = typeV.toString();
+    if(typeS == "MSA") {
+        type = AccountType::MSA;
+    } else if (typeS == "Mojang") {
+        type = AccountType::Mojang;
+    } else {
+        qWarning() << "Failed to parse account data: type is not recognized.";
+        return false;
+    }
+
+    if(type == AccountType::Mojang) {
+        legacy = data.value("legacy").toBool(false);
+        canMigrateToMSA = data.value("canMigrateToMSA").toBool(false);
+    }
+
+    if(type == AccountType::MSA) {
+        msaToken = tokenFromJSONV3(data, "msa");
+        userToken = tokenFromJSONV3(data, "utoken");
+        xboxApiToken = tokenFromJSONV3(data, "xrp-main");
+        mojangservicesToken = tokenFromJSONV3(data, "xrp-mc");
+    }
+
+    yggdrasilToken = tokenFromJSONV3(data, "ygg");
+    minecraftProfile = profileFromJSONV3(data, "profile");
+
+    validity_ = minecraftProfile.validity;
+
+    return true;
+}
+
+QJsonObject AccountData::saveState() const {
+    QJsonObject output;
+    if(type == AccountType::Mojang) {
+        output["type"] = "Mojang";
+        if(legacy) {
+            output["legacy"] = true;
+        }
+        if(canMigrateToMSA) {
+            output["canMigrateToMSA"] = true;
+        }
+    }
+    else if (type == AccountType::MSA) {
+        output["type"] = "MSA";
+        tokenToJSONV3(output, msaToken, "msa");
+        tokenToJSONV3(output, userToken, "utoken");
+        tokenToJSONV3(output, xboxApiToken, "xrp-main");
+        tokenToJSONV3(output, mojangservicesToken, "xrp-mc");
+    }
+
+    tokenToJSONV3(output, yggdrasilToken, "ygg");
+    profileToJSONV3(output, minecraftProfile, "profile");
+    return output;
+}
+
+QString AccountData::userName() const {
+    if(type != AccountType::Mojang) {
+        return QString();
+    }
+    return yggdrasilToken.extra["userName"].toString();
+}
+
+QString AccountData::accessToken() const {
+    return yggdrasilToken.token;
+}
+
+QString AccountData::clientToken() const {
+    if(type != AccountType::Mojang) {
+        return QString();
+    }
+    return yggdrasilToken.extra["clientToken"].toString();
+}
+
+void AccountData::setClientToken(QString clientToken) {
+    if(type != AccountType::Mojang) {
+        return;
+    }
+    yggdrasilToken.extra["clientToken"] = clientToken;
+}
+
+void AccountData::generateClientTokenIfMissing() {
+    if(yggdrasilToken.extra.contains("clientToken")) {
+        return;
+    }
+    invalidateClientToken();
+}
+
+void AccountData::invalidateClientToken() {
+    if(type != AccountType::Mojang) {
+        return;
+    }
+    yggdrasilToken.extra["clientToken"] = QUuid::createUuid().toString().remove(QRegExp("[{-}]"));
+}
+
+QString AccountData::profileId() const {
+    return minecraftProfile.id;
+}
+
+QString AccountData::profileName() const {
+    return minecraftProfile.name;
+}
+
+QString AccountData::accountDisplayString() const {
+    switch(type) {
+        case AccountType::Mojang: {
+            return userName();
+        }
+        case AccountType::MSA: {
+            if(xboxApiToken.extra.contains("gtg")) {
+                return xboxApiToken.extra["gtg"].toString();
+            }
+            return "Xbox profile missing";
+        }
+        default: {
+            return "Invalid Account";
+        }
+    }
+}
diff --git a/launcher/minecraft/auth/AccountData.h b/launcher/minecraft/auth/AccountData.h
new file mode 100644
index 00000000..b2d09cb0
--- /dev/null
+++ b/launcher/minecraft/auth/AccountData.h
@@ -0,0 +1,73 @@
+#pragma once
+#include <QString>
+#include <QByteArray>
+#include <QVector>
+#include <katabasis/Bits.h>
+#include <QJsonObject>
+
+struct Skin {
+    QString id;
+    QString url;
+    QString variant;
+
+    QByteArray data;
+};
+
+struct Cape {
+    QString id;
+    QString url;
+    QString alias;
+
+    QByteArray data;
+};
+
+struct MinecraftProfile {
+    QString id;
+    QString name;
+    Skin skin;
+    int currentCape = -1;
+    QVector<Cape> capes;
+    Katabasis::Validity validity = Katabasis::Validity::None;
+};
+
+enum class AccountType {
+    MSA,
+    Mojang
+};
+
+struct AccountData {
+    QJsonObject saveState() const;
+    bool resumeStateFromV2(QJsonObject data);
+    bool resumeStateFromV3(QJsonObject data);
+
+    //! userName for Mojang accounts, gamertag for MSA
+    QString accountDisplayString() const;
+
+    //! Only valid for Mojang accounts. MSA does not preserve this information
+    QString userName() const;
+
+    //! Only valid for Mojang accounts.
+    QString clientToken() const;
+    void setClientToken(QString clientToken);
+    void invalidateClientToken();
+    void generateClientTokenIfMissing();
+
+    //! Yggdrasil access token, as passed to the game.
+    QString accessToken() const;
+
+    QString profileId() const;
+    QString profileName() const;
+
+    AccountType type = AccountType::MSA;
+    bool legacy = false;
+    bool canMigrateToMSA = false;
+
+    Katabasis::Token msaToken;
+    Katabasis::Token userToken;
+    Katabasis::Token xboxApiToken;
+    Katabasis::Token mojangservicesToken;
+
+    Katabasis::Token yggdrasilToken;
+    MinecraftProfile minecraftProfile;
+    Katabasis::Validity validity_ = Katabasis::Validity::None;
+};
diff --git a/launcher/minecraft/auth/MojangAccountList.cpp b/launcher/minecraft/auth/AccountList.cpp
index e584cb3b..59028b60 100644
--- a/launcher/minecraft/auth/MojangAccountList.cpp
+++ b/launcher/minecraft/auth/AccountList.cpp
@@ -13,8 +13,8 @@
  * limitations under the License.
  */
 
-#include "MojangAccountList.h"
-#include "MojangAccount.h"
+#include "AccountList.h"
+#include "AccountData.h"
 
 #include <QIODevice>
 #include <QFile>
@@ -28,31 +28,49 @@
 #include <QDebug>
 
 #include <FileSystem.h>
+#include <QSaveFile>
 
-#define ACCOUNT_LIST_FORMAT_VERSION 2
+enum AccountListVersion {
+    MojangOnly = 2,
+    MojangMSA = 3
+};
 
-MojangAccountList::MojangAccountList(QObject *parent) : QAbstractListModel(parent)
-{
-}
+AccountList::AccountList(QObject *parent) : QAbstractListModel(parent) { }
 
-MojangAccountPtr MojangAccountList::findAccount(const QString &username) const
-{
-    for (int i = 0; i < count(); i++)
-    {
-        MojangAccountPtr account = at(i);
-        if (account->username() == username)
-            return account;
+int AccountList::findAccountByProfileId(const QString& profileId) const {
+    for (int i = 0; i < count(); i++) {
+        MinecraftAccountPtr account = at(i);
+        if (account->profileId() == profileId) {
+            return i;
+        }
     }
-    return nullptr;
+    return -1;
 }
 
-const MojangAccountPtr MojangAccountList::at(int i) const
+const MinecraftAccountPtr AccountList::at(int i) const
 {
-    return MojangAccountPtr(m_accounts.at(i));
+    return MinecraftAccountPtr(m_accounts.at(i));
 }
 
-void MojangAccountList::addAccount(const MojangAccountPtr account)
+void AccountList::addAccount(const MinecraftAccountPtr account)
 {
+    // We only ever want accounts with valid profiles.
+    // Keeping profile-less accounts is pointless and serves no purpose.
+    auto profileId = account->profileId();
+    if(!profileId.size()) {
+        return;
+    }
+
+    // override/replace existing account with the same profileId
+    auto existingAccount = findAccountByProfileId(profileId);
+    if(existingAccount != -1) {
+        m_accounts[existingAccount] = account;
+        emit dataChanged(index(existingAccount), index(existingAccount, columnCount(QModelIndex()) - 1));
+        onListChanged();
+        return;
+    }
+
+    // if we don't have this porfileId yet, add the account to the end
     int row = m_accounts.count();
     beginInsertRows(QModelIndex(), row, row);
     connect(account.get(), SIGNAL(changed()), SLOT(accountChanged()));
@@ -61,24 +79,7 @@ void MojangAccountList::addAccount(const MojangAccountPtr account)
     onListChanged();
 }
 
-void MojangAccountList::removeAccount(const QString &username)
-{
-    int idx = 0;
-    for (auto account : m_accounts)
-    {
-        if (account->username() == username)
-        {
-            beginRemoveRows(QModelIndex(), idx, idx);
-            m_accounts.removeOne(account);
-            endRemoveRows();
-            return;
-        }
-        idx++;
-    }
-    onListChanged();
-}
-
-void MojangAccountList::removeAccount(QModelIndex index)
+void AccountList::removeAccount(QModelIndex index)
 {
     int row = index.row();
     if(index.isValid() && row >= 0 && row < m_accounts.size())
@@ -96,19 +97,19 @@ void MojangAccountList::removeAccount(QModelIndex index)
     }
 }
 
-MojangAccountPtr MojangAccountList::activeAccount() const
+MinecraftAccountPtr AccountList::activeAccount() const
 {
     return m_activeAccount;
 }
 
-void MojangAccountList::setActiveAccount(const QString &username)
+void AccountList::setActiveAccount(const QString &profileId)
 {
-    if (username.isEmpty() && m_activeAccount)
+    if (profileId.isEmpty() && m_activeAccount)
     {
         int idx = 0;
         auto prevActiveAcc = m_activeAccount;
         m_activeAccount = nullptr;
-        for (MojangAccountPtr account : m_accounts)
+        for (MinecraftAccountPtr account : m_accounts)
         {
             if (account == prevActiveAcc)
             {
@@ -125,9 +126,9 @@ void MojangAccountList::setActiveAccount(const QString &username)
         auto newActiveAccount = m_activeAccount;
         int newActiveAccountIdx = -1;
         int idx = 0;
-        for (MojangAccountPtr account : m_accounts)
+        for (MinecraftAccountPtr account : m_accounts)
         {
-            if (account->username() == username)
+            if (account->profileId() == profileId)
             {
                 newActiveAccount = account;
                 newActiveAccountIdx = idx;
@@ -148,13 +149,13 @@ void MojangAccountList::setActiveAccount(const QString &username)
     }
 }
 
-void MojangAccountList::accountChanged()
+void AccountList::accountChanged()
 {
     // the list changed. there is no doubt.
     onListChanged();
 }
 
-void MojangAccountList::onListChanged()
+void AccountList::onListChanged()
 {
     if (m_autosave)
         // TODO: Alert the user if this fails.
@@ -163,7 +164,7 @@ void MojangAccountList::onListChanged()
     emit listChanged();
 }
 
-void MojangAccountList::onActiveChanged()
+void AccountList::onActiveChanged()
 {
     if (m_autosave)
         saveList();
@@ -171,12 +172,12 @@ void MojangAccountList::onActiveChanged()
     emit activeAccountChanged();
 }
 
-int MojangAccountList::count() const
+int AccountList::count() const
 {
     return m_accounts.count();
 }
 
-QVariant MojangAccountList::data(const QModelIndex &index, int role) const
+QVariant AccountList::data(const QModelIndex &index, int role) const
 {
     if (!index.isValid())
         return QVariant();
@@ -184,51 +185,61 @@ QVariant MojangAccountList::data(const QModelIndex &index, int role) const
     if (index.row() > count())
         return QVariant();
 
-    MojangAccountPtr account = at(index.row());
+    MinecraftAccountPtr account = at(index.row());
 
     switch (role)
     {
-    case Qt::DisplayRole:
-        switch (index.column())
-        {
-        case NameColumn:
-            return account->username();
+        case Qt::DisplayRole:
+            switch (index.column())
+            {
+            case NameColumn:
+                return account->accountDisplayString();
 
-        default:
-            return QVariant();
-        }
+            case TypeColumn: {
+                auto typeStr = account->typeString();
+                typeStr[0] = typeStr[0].toUpper();
+                return typeStr;
+            }
 
-    case Qt::ToolTipRole:
-        return account->username();
+            case ProfileNameColumn: {
+                return account->profileName();
+            }
 
-    case PointerRole:
-        return qVariantFromValue(account);
+            default:
+                return QVariant();
+            }
 
-    case Qt::CheckStateRole:
-        switch (index.column())
-        {
-        case ActiveColumn:
-            return account == m_activeAccount ? Qt::Checked : Qt::Unchecked;
-        }
+        case Qt::ToolTipRole:
+            return account->accountDisplayString();
 
-    default:
-        return QVariant();
+        case PointerRole:
+            return qVariantFromValue(account);
+
+        case Qt::CheckStateRole:
+            switch (index.column())
+            {
+                case NameColumn:
+                    return account == m_activeAccount ? Qt::Checked : Qt::Unchecked;
+            }
+
+        default:
+            return QVariant();
     }
 }
 
-QVariant MojangAccountList::headerData(int section, Qt::Orientation orientation, int role) const
+QVariant AccountList::headerData(int section, Qt::Orientation orientation, int role) const
 {
     switch (role)
     {
     case Qt::DisplayRole:
         switch (section)
         {
-        case ActiveColumn:
-            return tr("Active?");
-
         case NameColumn:
-            return tr("Name");
-
+            return tr("Account");
+        case TypeColumn:
+            return tr("Type");
+        case ProfileNameColumn:
+            return tr("Profile");
         default:
             return QVariant();
         }
@@ -237,8 +248,11 @@ QVariant MojangAccountList::headerData(int section, Qt::Orientation orientation,
         switch (section)
         {
         case NameColumn:
-            return tr("The name of the version.");
-
+            return tr("User name of the account.");
+        case TypeColumn:
+            return tr("Type of the account - Mojang or MSA.");
+        case ProfileNameColumn:
+            return tr("Name of the Minecraft profile associated with the account.");
         default:
             return QVariant();
         }
@@ -248,18 +262,18 @@ QVariant MojangAccountList::headerData(int section, Qt::Orientation orientation,
     }
 }
 
-int MojangAccountList::rowCount(const QModelIndex &) const
+int AccountList::rowCount(const QModelIndex &) const
 {
     // Return count
     return count();
 }
 
-int MojangAccountList::columnCount(const QModelIndex &) const
+int AccountList::columnCount(const QModelIndex &) const
 {
-    return 2;
+    return NUM_COLUMNS;
 }
 
-Qt::ItemFlags MojangAccountList::flags(const QModelIndex &index) const
+Qt::ItemFlags AccountList::flags(const QModelIndex &index) const
 {
     if (index.row() < 0 || index.row() >= rowCount(index) || !index.isValid())
     {
@@ -269,7 +283,7 @@ Qt::ItemFlags MojangAccountList::flags(const QModelIndex &index) const
     return Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
 }
 
-bool MojangAccountList::setData(const QModelIndex &index, const QVariant &value, int role)
+bool AccountList::setData(const QModelIndex &index, const QVariant &value, int role)
 {
     if (index.row() < 0 || index.row() >= rowCount(index) || !index.isValid())
     {
@@ -280,8 +294,8 @@ bool MojangAccountList::setData(const QModelIndex &index, const QVariant &value,
     {
         if(value == Qt::Checked)
         {
-            MojangAccountPtr account = this->at(index.row());
-            this->setActiveAccount(account->username());
+            MinecraftAccountPtr account = at(index.row());
+            setActiveAccount(account->profileId());
         }
     }
 
@@ -289,31 +303,21 @@ bool MojangAccountList::setData(const QModelIndex &index, const QVariant &value,
     return true;
 }
 
-void MojangAccountList::updateListData(QList<MojangAccountPtr> versions)
-{
-    beginResetModel();
-    m_accounts = versions;
-    endResetModel();
-}
-
-bool MojangAccountList::loadList(const QString &filePath)
+bool AccountList::loadList()
 {
-    QString path = filePath;
-    if (path.isEmpty())
-        path = m_listFilePath;
-    if (path.isEmpty())
+    if (m_listFilePath.isEmpty())
     {
         qCritical() << "Can't load Mojang account list. No file path given and no default set.";
         return false;
     }
 
-    QFile file(path);
+    QFile file(m_listFilePath);
 
     // Try to open the file and fail if we can't.
     // TODO: We should probably report this error to the user.
     if (!file.open(QIODevice::ReadOnly))
     {
-        qCritical() << QString("Failed to read the account list file (%1).").arg(path).toUtf8();
+        qCritical() << QString("Failed to read the account list file (%1).").arg(m_listFilePath).toUtf8();
         return false;
     }
 
@@ -343,121 +347,168 @@ bool MojangAccountList::loadList(const QString &filePath)
     QJsonObject root = jsonDoc.object();
 
     // Make sure the format version matches.
-    if (root.value("formatVersion").toVariant().toInt() != ACCOUNT_LIST_FORMAT_VERSION)
-    {
-        QString newName = "accounts-old.json";
-        qWarning() << "Format version mismatch when loading account list. Existing one will be renamed to"
-                    << newName;
+    auto listVersion = root.value("formatVersion").toVariant().toInt();
+    switch(listVersion) {
+        case AccountListVersion::MojangOnly: {
+            return loadV2(root);
+        }
+        break;
+        case AccountListVersion::MojangMSA: {
+            return loadV3(root);
+        }
+        break;
+        default: {
+            QString newName = "accounts-old.json";
+            qWarning() << "Unknown format version when loading account list. Existing one will be renamed to" << newName;
+            // Attempt to rename the old version.
+            file.rename(newName);
+            return false;
+        }
+    }
+}
 
-        // Attempt to rename the old version.
-        file.rename(newName);
-        return false;
+bool AccountList::loadV2(QJsonObject& root) {
+    beginResetModel();
+    auto activeUserName = root.value("activeAccount").toString("");
+    QJsonArray accounts = root.value("accounts").toArray();
+    for (QJsonValue accountVal : accounts)
+    {
+        QJsonObject accountObj = accountVal.toObject();
+        MinecraftAccountPtr account = MinecraftAccount::loadFromJsonV2(accountObj);
+        if (account.get() != nullptr)
+        {
+            auto profileId = account->profileId();
+            if(!profileId.size()) {
+                continue;
+            }
+            if(findAccountByProfileId(profileId) != -1) {
+                continue;
+            }
+            connect(account.get(), &MinecraftAccount::changed, this, &AccountList::accountChanged);
+            m_accounts.append(account);
+            if (activeUserName.size() && account->mojangUserName() == activeUserName) {
+                m_activeAccount = account;
+            }
+        }
+        else
+        {
+            qWarning() << "Failed to load an account.";
+        }
     }
+    endResetModel();
+    return true;
+}
 
-    // Now, load the accounts array.
+bool AccountList::loadV3(QJsonObject& root) {
     beginResetModel();
     QJsonArray accounts = root.value("accounts").toArray();
     for (QJsonValue accountVal : accounts)
     {
         QJsonObject accountObj = accountVal.toObject();
-        MojangAccountPtr account = MojangAccount::loadFromJson(accountObj);
+        MinecraftAccountPtr account = MinecraftAccount::loadFromJsonV3(accountObj);
         if (account.get() != nullptr)
         {
-            connect(account.get(), SIGNAL(changed()), SLOT(accountChanged()));
+            auto profileId = account->profileId();
+            if(!profileId.size()) {
+                continue;
+            }
+            if(findAccountByProfileId(profileId) != -1) {
+                continue;
+            }
+            connect(account.get(), &MinecraftAccount::changed, this, &AccountList::accountChanged);
             m_accounts.append(account);
+            if(accountObj.value("active").toBool(false)) {
+                m_activeAccount = account;
+            }
         }
         else
         {
             qWarning() << "Failed to load an account.";
         }
     }
-    // Load the active account.
-    m_activeAccount = findAccount(root.value("activeAccount").toString(""));
     endResetModel();
     return true;
 }
 
-bool MojangAccountList::saveList(const QString &filePath)
+
+bool AccountList::saveList()
 {
-    QString path(filePath);
-    if (path.isEmpty())
-        path = m_listFilePath;
-    if (path.isEmpty())
+    if (m_listFilePath.isEmpty())
     {
         qCritical() << "Can't save Mojang account list. No file path given and no default set.";
         return false;
     }
 
     // make sure the parent folder exists
-    if(!FS::ensureFilePathExists(path))
+    if(!FS::ensureFilePathExists(m_listFilePath))
         return false;
 
     // make sure the file wasn't overwritten with a folder before (fixes a bug)
-    QFileInfo finfo(path);
+    QFileInfo finfo(m_listFilePath);
     if(finfo.isDir())
     {
-        QDir badDir(path);
+        QDir badDir(m_listFilePath);
         badDir.removeRecursively();
     }
 
-    qDebug() << "Writing account list to" << path;
+    qDebug() << "Writing account list to" << m_listFilePath;
 
     qDebug() << "Building JSON data structure.";
     // Build the JSON document to write to the list file.
     QJsonObject root;
 
-    root.insert("formatVersion", ACCOUNT_LIST_FORMAT_VERSION);
+    root.insert("formatVersion", AccountListVersion::MojangMSA);
 
     // Build a list of accounts.
     qDebug() << "Building account array.";
     QJsonArray accounts;
-    for (MojangAccountPtr account : m_accounts)
+    for (MinecraftAccountPtr account : m_accounts)
     {
         QJsonObject accountObj = account->saveToJson();
+        if(m_activeAccount == account) {
+            accountObj["active"] = true;
+        }
         accounts.append(accountObj);
     }
 
     // Insert the account list into the root object.
     root.insert("accounts", accounts);
 
-    if(m_activeAccount)
-    {
-        // Save the active account.
-        root.insert("activeAccount", m_activeAccount->username());
-    }
-
     // Create a JSON document object to convert our JSON to bytes.
     QJsonDocument doc(root);
 
     // Now that we're done building the JSON object, we can write it to the file.
     qDebug() << "Writing account list to file.";
-    QFile file(path);
+    QSaveFile file(m_listFilePath);
 
     // Try to open the file and fail if we can't.
     // TODO: We should probably report this error to the user.
     if (!file.open(QIODevice::WriteOnly))
     {
-        qCritical() << QString("Failed to read the account list file (%1).").arg(path).toUtf8();
+        qCritical() << QString("Failed to read the account list file (%1).").arg(m_listFilePath).toUtf8();
         return false;
     }
 
     // Write the JSON to the file.
     file.write(doc.toJson());
     file.setPermissions(QFile::ReadOwner|QFile::WriteOwner|QFile::ReadUser|QFile::WriteUser);
-    file.close();
-
-    qDebug() << "Saved account list to" << path;
-
-    return true;
+    if(file.commit()) {
+        qDebug() << "Saved account list to" << m_listFilePath;
+        return true;
+    }
+    else {
+        qDebug() << "Failed to save accounts to" << m_listFilePath;
+        return false;
+    }
 }
 
-void MojangAccountList::setListFilePath(QString path, bool autosave)
+void AccountList::setListFilePath(QString path, bool autosave)
 {
     m_listFilePath = path;
     m_autosave = autosave;
 }
 
-bool MojangAccountList::anyAccountIsValid()
+bool AccountList::anyAccountIsValid()
 {
     for(auto account:m_accounts)
     {
diff --git a/launcher/minecraft/auth/AccountList.h b/launcher/minecraft/auth/AccountList.h
new file mode 100644
index 00000000..ac3684ee
--- /dev/null
+++ b/launcher/minecraft/auth/AccountList.h
@@ -0,0 +1,118 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "MinecraftAccount.h"
+
+#include <QObject>
+#include <QVariant>
+#include <QAbstractListModel>
+#include <QSharedPointer>
+
+/*!
+ * List of available Mojang accounts.
+ * This should be loaded in the background by MultiMC on startup.
+ */
+class AccountList : public QAbstractListModel
+{
+    Q_OBJECT
+public:
+    enum ModelRoles
+    {
+        PointerRole = 0x34B1CB48
+    };
+
+    enum VListColumns
+    {
+        // TODO: Add icon column.
+        NameColumn = 0,
+        ProfileNameColumn,
+        TypeColumn,
+
+        NUM_COLUMNS
+    };
+
+    explicit AccountList(QObject *parent = 0);
+
+    const MinecraftAccountPtr at(int i) const;
+    int count() const;
+
+    //////// List Model Functions ////////
+    QVariant data(const QModelIndex &index, int role) const override;
+    virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
+    virtual int rowCount(const QModelIndex &parent) const override;
+    virtual int columnCount(const QModelIndex &parent) const override;
+    virtual Qt::ItemFlags flags(const QModelIndex &index) const override;
+    virtual bool setData(const QModelIndex &index, const QVariant &value, int role) override;
+
+    void addAccount(const MinecraftAccountPtr account);
+    void removeAccount(QModelIndex index);
+    int findAccountByProfileId(const QString &profileId) const;
+
+    /*!
+     * Sets the path to load/save the list file from/to.
+     * If autosave is true, this list will automatically save to the given path whenever it changes.
+     * THIS FUNCTION DOES NOT LOAD THE LIST. If you set autosave, be sure to call loadList() immediately
+     * after calling this function to ensure an autosaved change doesn't overwrite the list you intended
+     * to load.
+     */
+    void setListFilePath(QString path, bool autosave = false);
+
+    bool loadList();
+    bool loadV2(QJsonObject &root);
+    bool loadV3(QJsonObject &root);
+    bool saveList();
+
+    MinecraftAccountPtr activeAccount() const;
+    void setActiveAccount(const QString &profileId);
+    bool anyAccountIsValid();
+
+signals:
+    void listChanged();
+    void activeAccountChanged();
+
+public slots:
+    /**
+     * This is called when one of the accounts changes and the list needs to be updated
+     */
+    void accountChanged();
+
+protected:
+    /*!
+     * Called whenever the list changes.
+     * This emits the listChanged() signal and autosaves the list (if autosave is enabled).
+     */
+    void onListChanged();
+
+    /*!
+     * Called whenever the active account changes.
+     * Emits the activeAccountChanged() signal and autosaves the list if enabled.
+     */
+    void onActiveChanged();
+
+    QList<MinecraftAccountPtr> m_accounts;
+
+    MinecraftAccountPtr m_activeAccount;
+
+    //! Path to the account list file. Empty string if there isn't one.
+    QString m_listFilePath;
+
+    /*!
+     * If true, the account list will automatically save to the account list path when it changes.
+     * Ignored if m_listFilePath is blank.
+     */
+    bool m_autosave = false;
+};
diff --git a/launcher/minecraft/auth/AccountTask.cpp b/launcher/minecraft/auth/AccountTask.cpp
new file mode 100644
index 00000000..c06be42b
--- /dev/null
+++ b/launcher/minecraft/auth/AccountTask.cpp
@@ -0,0 +1,69 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "AccountTask.h"
+#include "MinecraftAccount.h"
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+#include <QJsonDocument>
+#include <QNetworkReply>
+#include <QByteArray>
+
+#include <Env.h>
+
+#include <BuildConfig.h>
+
+#include <QDebug>
+
+AccountTask::AccountTask(AccountData *data, QObject *parent)
+    : Task(parent), m_data(data)
+{
+    changeState(STATE_CREATED);
+}
+
+QString AccountTask::getStateMessage() const
+{
+    switch (m_accountState)
+    {
+    case STATE_CREATED:
+        return "Waiting...";
+    case STATE_WORKING:
+        return tr("Sending request to auth servers...");
+    case STATE_SUCCEEDED:
+        return tr("Authentication task succeeded.");
+    case STATE_FAILED_SOFT:
+        return tr("Failed to contact the authentication server.");
+    case STATE_FAILED_HARD:
+        return tr("Failed to authenticate.");
+    default:
+        return tr("...");
+    }
+}
+
+void AccountTask::changeState(AccountTask::State newState, QString reason)
+{
+    m_accountState = newState;
+    setStatus(getStateMessage());
+    if (newState == STATE_SUCCEEDED)
+    {
+        emitSucceeded();
+    }
+    else if (newState == STATE_FAILED_HARD || newState == STATE_FAILED_SOFT)
+    {
+        emitFailed(reason);
+    }
+}
diff --git a/launcher/minecraft/auth/YggdrasilTask.h b/launcher/minecraft/auth/AccountTask.h
index 8af2e132..3f08096f 100644
--- a/launcher/minecraft/auth/YggdrasilTask.h
+++ b/launcher/minecraft/auth/AccountTask.h
@@ -22,19 +22,17 @@
 #include <QTimer>
 #include <qsslerror.h>
 
-#include "MojangAccount.h"
+#include "MinecraftAccount.h"
 
 class QNetworkReply;
 
-/**
- * A Yggdrasil task is a task that performs an operation on a given mojang account.
- */
-class YggdrasilTask : public Task
+class AccountTask : public Task
 {
+    friend class AuthContext;
     Q_OBJECT
 public:
-    explicit YggdrasilTask(MojangAccount * account, QObject *parent = 0);
-    virtual ~YggdrasilTask() {};
+    explicit AccountTask(AccountData * data, QObject *parent = 0);
+    virtual ~AccountTask() {};
 
     /**
      * assign a session to this task. the session will be filled with required infomration
@@ -52,7 +50,7 @@ public:
     }
 
     /**
-     * Class describing a Yggdrasil error response.
+     * Class describing a Account error response.
      */
     struct Error
     {
@@ -75,45 +73,17 @@ public:
     enum State
     {
         STATE_CREATED,
-        STATE_SENDING_REQUEST,
-        STATE_PROCESSING_RESPONSE,
+        STATE_WORKING,
         STATE_FAILED_SOFT, //!< soft failure. this generally means the user auth details haven't been invalidated
         STATE_FAILED_HARD, //!< hard failure. auth is invalid
         STATE_SUCCEEDED
-    } m_state = STATE_CREATED;
-
-protected:
-
-    virtual void executeTask() override;
-
-    /**
-     * Gets the JSON object that will be sent to the authentication server.
-     * Should be overridden by subclasses.
-     */
-    virtual QJsonObject getRequestContent() const = 0;
-
-    /**
-     * Gets the endpoint to POST to.
-     * No leading slash.
-     */
-    virtual QString getEndpoint() const = 0;
+    } m_accountState = STATE_CREATED;
 
-    /**
-     * Processes the response received from the server.
-     * If an error occurred, this should emit a failed signal and return false.
-     * If Yggdrasil gave an error response, it should call setError() first, and then return false.
-     * Otherwise, it should return true.
-     * Note: If the response from the server was blank, and the HTTP code was 200, this function is called with
-     * an empty QJsonObject.
-     */
-    virtual void processResponse(QJsonObject responseData) = 0;
+    State accountState() {
+        return m_accountState;
+    }
 
-    /**
-     * Processes an error response received from the server.
-     * The default implementation will read data from Yggdrasil's standard error response format and set it as this task's Error.
-     * \returns a QString error message that will be passed to emitFailed.
-     */
-    virtual void processError(QJsonObject responseData);
+protected:
 
     /**
      * Returns the state message for the given state.
@@ -122,30 +92,12 @@ protected:
      */
     virtual QString getStateMessage() const;
 
-protected
-slots:
-    void processReply();
-    void refreshTimers(qint64, qint64);
-    void heartbeat();
-    void sslErrors(QList<QSslError>);
-
+protected slots:
     void changeState(State newState, QString reason=QString());
-public
-slots:
-    virtual bool abort() override;
-    void abortByTimeout();
-    State state();
+
 protected:
     // FIXME: segfault disaster waiting to happen
-    MojangAccount *m_account = nullptr;
-    QNetworkReply *m_netReply = nullptr;
+    AccountData *m_data = nullptr;
     std::shared_ptr<Error> m_error;
-    QTimer timeout_keeper;
-    QTimer counter;
-    int count = 0; // num msec since time reset
-
-    const int timeout_max = 30000;
-    const int time_step = 50;
-
     AuthSessionPtr m_session;
 };
diff --git a/launcher/minecraft/auth/AuthSession.cpp b/launcher/minecraft/auth/AuthSession.cpp
index 4e858796..d44f9098 100644
--- a/launcher/minecraft/auth/AuthSession.cpp
+++ b/launcher/minecraft/auth/AuthSession.cpp
@@ -7,11 +7,13 @@
 QString AuthSession::serializeUserProperties()
 {
     QJsonObject userAttrs;
+    /*
     for (auto key : u.properties.keys())
     {
         auto array = QJsonArray::fromStringList(u.properties.values(key));
         userAttrs.insert(key, array);
     }
+    */
     QJsonDocument value(userAttrs);
     return value.toJson(QJsonDocument::Compact);
 
diff --git a/launcher/minecraft/auth/AuthSession.h b/launcher/minecraft/auth/AuthSession.h
index 29958597..d77435b8 100644
--- a/launcher/minecraft/auth/AuthSession.h
+++ b/launcher/minecraft/auth/AuthSession.h
@@ -4,13 +4,7 @@
 #include <QMultiMap>
 #include <memory>
 
-class MojangAccount;
-
-struct User
-{
-    QString id;
-    QMultiMap<QString, QString> properties;
-};
+class MinecraftAccount;
 
 struct AuthSession
 {
@@ -21,13 +15,12 @@ struct AuthSession
     enum Status
     {
         Undetermined,
+        RequiresOAuth,
         RequiresPassword,
         PlayableOffline,
         PlayableOnline
     } status = Undetermined;
 
-    User u;
-
     // client token
     QString client_token;
     // account user name
@@ -46,7 +39,7 @@ struct AuthSession
     bool auth_server_online = false;
     // Did the user request online mode?
     bool wants_online = true;
-    std::shared_ptr<MojangAccount> m_accountPtr;
+    std::shared_ptr<MinecraftAccount> m_accountPtr;
 };
 
 typedef std::shared_ptr<AuthSession> AuthSessionPtr;
diff --git a/launcher/minecraft/auth/MinecraftAccount.cpp b/launcher/minecraft/auth/MinecraftAccount.cpp
new file mode 100644
index 00000000..671f9c38
--- /dev/null
+++ b/launcher/minecraft/auth/MinecraftAccount.cpp
@@ -0,0 +1,303 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Authors: Orochimarufan <orochimarufan.x3@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MinecraftAccount.h"
+#include "flows/AuthContext.h"
+
+#include <QUuid>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QRegExp>
+#include <QStringList>
+#include <QJsonDocument>
+
+#include <QDebug>
+
+#include <QPainter>
+#include <minecraft/auth/flows/MSASilent.h>
+#include <minecraft/auth/flows/MSAInteractive.h>
+
+#include <minecraft/auth/flows/MojangRefresh.h>
+#include <minecraft/auth/flows/MojangLogin.h>
+
+MinecraftAccountPtr MinecraftAccount::loadFromJsonV2(const QJsonObject& json) {
+    MinecraftAccountPtr account(new MinecraftAccount());
+    if(account->data.resumeStateFromV2(json)) {
+        return account;
+    }
+    return nullptr;
+}
+
+MinecraftAccountPtr MinecraftAccount::loadFromJsonV3(const QJsonObject& json) {
+    MinecraftAccountPtr account(new MinecraftAccount());
+    if(account->data.resumeStateFromV3(json)) {
+        return account;
+    }
+    return nullptr;
+}
+
+MinecraftAccountPtr MinecraftAccount::createFromUsername(const QString &username)
+{
+    MinecraftAccountPtr account(new MinecraftAccount());
+    account->data.type = AccountType::Mojang;
+    account->data.yggdrasilToken.extra["userName"] = username;
+    account->data.yggdrasilToken.extra["clientToken"] = QUuid::createUuid().toString().remove(QRegExp("[{}-]"));
+    return account;
+}
+
+MinecraftAccountPtr MinecraftAccount::createBlankMSA()
+{
+    MinecraftAccountPtr account(new MinecraftAccount());
+    account->data.type = AccountType::MSA;
+    return account;
+}
+
+
+QJsonObject MinecraftAccount::saveToJson() const
+{
+    return data.saveState();
+}
+
+AccountStatus MinecraftAccount::accountStatus() const {
+    if(data.type == AccountType::Mojang) {
+        if (data.accessToken().isEmpty()) {
+            return NotVerified;
+        }
+        else {
+            return Verified;
+        }
+    }
+    // MSA
+    // FIXME: this is extremely crude and probably wrong
+    if(data.msaToken.token.isEmpty()) {
+        return NotVerified;
+    }
+    else {
+        return Verified;
+    }
+}
+
+QPixmap MinecraftAccount::getFace() const {
+    QPixmap skinTexture;
+    if(!skinTexture.loadFromData(data.minecraftProfile.skin.data, "PNG")) {
+        return QPixmap();
+    }
+    QPixmap skin = QPixmap(8, 8);
+    QPainter painter(&skin);
+    painter.drawPixmap(0, 0, skinTexture.copy(8, 8, 8, 8));
+    painter.drawPixmap(0, 0, skinTexture.copy(40, 8, 8, 8));
+    return skin.scaled(64, 64, Qt::KeepAspectRatio);
+}
+
+
+std::shared_ptr<AccountTask> MinecraftAccount::login(AuthSessionPtr session, QString password)
+{
+    Q_ASSERT(m_currentTask.get() == nullptr);
+
+    // take care of the true offline status
+    if (accountStatus() == NotVerified && password.isEmpty())
+    {
+        if (session)
+        {
+            session->status = AuthSession::RequiresPassword;
+            fillSession(session);
+        }
+        return nullptr;
+    }
+
+    if(accountStatus() == Verified && !session->wants_online)
+    {
+        session->status = AuthSession::PlayableOffline;
+        session->auth_server_online = false;
+        fillSession(session);
+        return nullptr;
+    }
+    else
+    {
+        if (password.isEmpty())
+        {
+            m_currentTask.reset(new MojangRefresh(&data));
+        }
+        else
+        {
+            m_currentTask.reset(new MojangLogin(&data, password));
+        }
+        m_currentTask->assignSession(session);
+
+        connect(m_currentTask.get(), SIGNAL(succeeded()), SLOT(authSucceeded()));
+        connect(m_currentTask.get(), SIGNAL(failed(QString)), SLOT(authFailed(QString)));
+    }
+    return m_currentTask;
+}
+
+std::shared_ptr<AccountTask> MinecraftAccount::loginMSA(AuthSessionPtr session) {
+    Q_ASSERT(m_currentTask.get() == nullptr);
+
+    if(accountStatus() == Verified && !session->wants_online)
+    {
+        session->status = AuthSession::PlayableOffline;
+        session->auth_server_online = false;
+        fillSession(session);
+        return nullptr;
+    }
+    else
+    {
+        m_currentTask.reset(new MSAInteractive(&data));
+        m_currentTask->assignSession(session);
+
+        connect(m_currentTask.get(), SIGNAL(succeeded()), SLOT(authSucceeded()));
+        connect(m_currentTask.get(), SIGNAL(failed(QString)), SLOT(authFailed(QString)));
+    }
+    return m_currentTask;
+}
+
+std::shared_ptr<AccountTask> MinecraftAccount::refresh(AuthSessionPtr session) {
+    Q_ASSERT(m_currentTask.get() == nullptr);
+
+    // take care of the true offline status
+    if (accountStatus() == NotVerified)
+    {
+        if (session)
+        {
+            if(data.type == AccountType::MSA) {
+                session->status = AuthSession::RequiresOAuth;
+            }
+            else {
+                session->status = AuthSession::RequiresPassword;
+            }
+            fillSession(session);
+        }
+        return nullptr;
+    }
+
+    if(accountStatus() == Verified && !session->wants_online)
+    {
+        session->status = AuthSession::PlayableOffline;
+        session->auth_server_online = false;
+        fillSession(session);
+        return nullptr;
+    }
+    else
+    {
+        if(data.type == AccountType::MSA) {
+            m_currentTask.reset(new MSASilent(&data));
+        }
+        else {
+            m_currentTask.reset(new MojangRefresh(&data));
+        }
+        m_currentTask->assignSession(session);
+
+        connect(m_currentTask.get(), SIGNAL(succeeded()), SLOT(authSucceeded()));
+        connect(m_currentTask.get(), SIGNAL(failed(QString)), SLOT(authFailed(QString)));
+    }
+    return m_currentTask;
+}
+
+
+void MinecraftAccount::authSucceeded()
+{
+    auto session = m_currentTask->getAssignedSession();
+    if (session)
+    {
+        session->status =
+            session->wants_online ? AuthSession::PlayableOnline : AuthSession::PlayableOffline;
+        fillSession(session);
+        session->auth_server_online = true;
+    }
+    m_currentTask.reset();
+    emit changed();
+}
+
+void MinecraftAccount::authFailed(QString reason)
+{
+    auto session = m_currentTask->getAssignedSession();
+    // This is emitted when the yggdrasil tasks time out or are cancelled.
+    // -> we treat the error as no-op
+    if (m_currentTask->accountState() == AccountTask::STATE_FAILED_SOFT)
+    {
+        if (session)
+        {
+            session->status = accountStatus() == Verified ? AuthSession::PlayableOffline : AuthSession::RequiresPassword;
+            session->auth_server_online = false;
+            fillSession(session);
+        }
+    }
+    else
+    {
+        // FIXME: MSA ...
+        data.yggdrasilToken.token = QString();
+        data.yggdrasilToken.validity = Katabasis::Validity::None;
+        data.validity_ = Katabasis::Validity::None;
+        emit changed();
+        if (session)
+        {
+            session->status = AuthSession::RequiresPassword;
+            session->auth_server_online = true;
+            fillSession(session);
+        }
+    }
+    m_currentTask.reset();
+}
+
+void MinecraftAccount::fillSession(AuthSessionPtr session)
+{
+    // the user name. you have to have an user name
+    // FIXME: not with MSA
+    session->username = data.userName();
+    // volatile auth token
+    session->access_token = data.accessToken();
+    // the semi-permanent client token
+    session->client_token = data.clientToken();
+    // profile name
+    session->player_name = data.profileName();
+    // profile ID
+    session->uuid = data.profileId();
+    // 'legacy' or 'mojang', depending on account type
+    session->user_type = typeString();
+    if (!session->access_token.isEmpty())
+    {
+        session->session = "token:" + data.accessToken() + ":" + data.profileId();
+    }
+    else
+    {
+        session->session = "-";
+    }
+    session->m_accountPtr = shared_from_this();
+}
+
+void MinecraftAccount::decrementUses()
+{
+    Usable::decrementUses();
+    if(!isInUse())
+    {
+        emit changed();
+        // FIXME: we now need a better way to identify accounts...
+        qWarning() << "Profile" << data.profileId() << "is no longer in use.";
+    }
+}
+
+void MinecraftAccount::incrementUses()
+{
+    bool wasInUse = isInUse();
+    Usable::incrementUses();
+    if(!wasInUse)
+    {
+        emit changed();
+        // FIXME: we now need a better way to identify accounts...
+        qWarning() << "Profile" << data.profileId() << "is now in use.";
+    }
+}
diff --git a/launcher/minecraft/auth/MojangAccount.h b/launcher/minecraft/auth/MinecraftAccount.h
index 3f6cbedd..72bb6bd4 100644
--- a/launcher/minecraft/auth/MojangAccount.h
+++ b/launcher/minecraft/auth/MinecraftAccount.h
@@ -21,17 +21,19 @@
 #include <QJsonObject>
 #include <QPair>
 #include <QMap>
+#include <QPixmap>
 
 #include <memory>
 #include "AuthSession.h"
 #include "Usable.h"
+#include "AccountData.h"
 
 class Task;
-class YggdrasilTask;
-class MojangAccount;
+class AccountTask;
+class MinecraftAccount;
 
-typedef std::shared_ptr<MojangAccount> MojangAccountPtr;
-Q_DECLARE_METATYPE(MojangAccountPtr)
+typedef std::shared_ptr<MinecraftAccount> MinecraftAccountPtr;
+Q_DECLARE_METATYPE(MinecraftAccountPtr)
 
 /**
  * A profile within someone's Mojang account.
@@ -59,75 +61,90 @@ enum AccountStatus
  * Said information may include things such as that account's username, client token, and access
  * token if the user chose to stay logged in.
  */
-class MojangAccount :
+class MinecraftAccount :
     public QObject,
     public Usable,
-    public std::enable_shared_from_this<MojangAccount>
+    public std::enable_shared_from_this<MinecraftAccount>
 {
     Q_OBJECT
 public: /* construction */
     //! Do not copy accounts. ever.
-    explicit MojangAccount(const MojangAccount &other, QObject *parent) = delete;
+    explicit MinecraftAccount(const MinecraftAccount &other, QObject *parent) = delete;
 
     //! Default constructor
-    explicit MojangAccount(QObject *parent = 0) : QObject(parent) {};
+    explicit MinecraftAccount(QObject *parent = 0) : QObject(parent) {};
 
-    //! Creates an empty account for the specified user name.
-    static MojangAccountPtr createFromUsername(const QString &username);
+    static MinecraftAccountPtr createFromUsername(const QString &username);
 
-    //! Loads a MojangAccount from the given JSON object.
-    static MojangAccountPtr loadFromJson(const QJsonObject &json);
+    static MinecraftAccountPtr createBlankMSA();
 
-    //! Saves a MojangAccount to a JSON object and returns it.
+    static MinecraftAccountPtr loadFromJsonV2(const QJsonObject &json);
+    static MinecraftAccountPtr loadFromJsonV3(const QJsonObject &json);
+
+    //! Saves a MinecraftAccount to a JSON object and returns it.
     QJsonObject saveToJson() const;
 
 public: /* manipulation */
-        /**
-     * Sets the currently selected profile to the profile with the given ID string.
-     * If profileId is not in the list of available profiles, the function will simply return
-     * false.
-     */
-    bool setCurrentProfile(const QString &profileId);
 
     /**
      * Attempt to login. Empty password means we use the token.
      * If the attempt fails because we already are performing some task, it returns false.
      */
-    std::shared_ptr<YggdrasilTask> login(AuthSessionPtr session, QString password = QString());
-    void invalidateClientToken();
+    std::shared_ptr<AccountTask> login(AuthSessionPtr session, QString password = QString());
+
+    std::shared_ptr<AccountTask> loginMSA(AuthSessionPtr session);
+
+    std::shared_ptr<AccountTask> refresh(AuthSessionPtr session);
 
 public: /* queries */
-    const QString &username() const
-    {
-        return m_username;
+    QString accountDisplayString() const {
+        return data.accountDisplayString();
     }
 
-    const QString &clientToken() const
-    {
-        return m_clientToken;
+    QString mojangUserName() const {
+        return data.userName();
     }
 
-    const QString &accessToken() const
-    {
-        return m_accessToken;
+    QString accessToken() const {
+        return data.accessToken();
     }
 
-    const QList<AccountProfile> &profiles() const
-    {
-        return m_profiles;
+    QString profileId() const {
+        return data.profileId();
     }
 
-    const User &user()
-    {
-        return m_user;
+    QString profileName() const {
+        return data.profileName();
     }
 
-    //! Returns the currently selected profile (if none, returns nullptr)
-    const AccountProfile *currentProfile() const;
+    QString typeString() const {
+        switch(data.type) {
+            case AccountType::Mojang: {
+                if(data.legacy) {
+                    return "legacy";
+                }
+                return "mojang";
+            }
+            break;
+            case AccountType::MSA: {
+                return "msa";
+            }
+            break;
+            default: {
+                return "unknown";
+            }
+        }
+    }
+
+    QPixmap getFace() const;
 
     //! Returns whether the account is NotVerified, Verified or Online
     AccountStatus accountStatus() const;
 
+    AccountData * accountData() {
+        return &data;
+    }
+
 signals:
     /**
      * This signal is emitted when the account changes
@@ -137,27 +154,10 @@ signals:
     // TODO: better signalling for the various possible state changes - especially errors
 
 protected: /* variables */
-    QString m_username;
-
-    // Used to identify the client - the user can have multiple clients for the same account
-    // Think: different launchers, all connecting to the same account/profile
-    QString m_clientToken;
-
-    // Blank if not logged in.
-    QString m_accessToken;
-
-    // Index of the selected profile within the list of available
-    // profiles. -1 if nothing is selected.
-    int m_currentProfile = -1;
-
-    // List of available profiles.
-    QList<AccountProfile> m_profiles;
-
-    // the user structure, whatever it is.
-    User m_user;
+    AccountData data;
 
     // current task we are executing here
-    std::shared_ptr<YggdrasilTask> m_currentTask;
+    std::shared_ptr<AccountTask> m_currentTask;
 
 protected: /* methods */
 
@@ -171,10 +171,4 @@ slots:
 
 private:
     void fillSession(AuthSessionPtr session);
-
-public:
-    friend class YggdrasilTask;
-    friend class AuthenticateTask;
-    friend class ValidateTask;
-    friend class RefreshTask;
 };
diff --git a/launcher/minecraft/auth/MojangAccount.cpp b/launcher/minecraft/auth/MojangAccount.cpp
deleted file mode 100644
index f5853fe3..00000000
--- a/launcher/minecraft/auth/MojangAccount.cpp
+++ /dev/null
@@ -1,315 +0,0 @@
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Authors: Orochimarufan <orochimarufan.x3@gmail.com>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "MojangAccount.h"
-#include "flows/RefreshTask.h"
-#include "flows/AuthenticateTask.h"
-
-#include <QUuid>
-#include <QJsonObject>
-#include <QJsonArray>
-#include <QRegExp>
-#include <QStringList>
-#include <QJsonDocument>
-
-#include <QDebug>
-
-MojangAccountPtr MojangAccount::loadFromJson(const QJsonObject &object)
-{
-    // The JSON object must at least have a username for it to be valid.
-    if (!object.value("username").isString())
-    {
-        qCritical() << "Can't load Mojang account info from JSON object. Username field is "
-                        "missing or of the wrong type.";
-        return nullptr;
-    }
-
-    QString username = object.value("username").toString("");
-    QString clientToken = object.value("clientToken").toString("");
-    QString accessToken = object.value("accessToken").toString("");
-
-    QJsonArray profileArray = object.value("profiles").toArray();
-    if (profileArray.size() < 1)
-    {
-        qCritical() << "Can't load Mojang account with username \"" << username
-                     << "\". No profiles found.";
-        return nullptr;
-    }
-
-    QList<AccountProfile> profiles;
-    for (QJsonValue profileVal : profileArray)
-    {
-        QJsonObject profileObject = profileVal.toObject();
-        QString id = profileObject.value("id").toString("");
-        QString name = profileObject.value("name").toString("");
-        bool legacy = profileObject.value("legacy").toBool(false);
-        if (id.isEmpty() || name.isEmpty())
-        {
-            qWarning() << "Unable to load a profile because it was missing an ID or a name.";
-            continue;
-        }
-        profiles.append({id, name, legacy});
-    }
-
-    MojangAccountPtr account(new MojangAccount());
-    if (object.value("user").isObject())
-    {
-        User u;
-        QJsonObject userStructure = object.value("user").toObject();
-        u.id = userStructure.value("id").toString();
-        /*
-        QJsonObject propMap = userStructure.value("properties").toObject();
-        for(auto key: propMap.keys())
-        {
-            auto values = propMap.operator[](key).toArray();
-            for(auto value: values)
-                u.properties.insert(key, value.toString());
-        }
-        */
-        account->m_user = u;
-    }
-    account->m_username = username;
-    account->m_clientToken = clientToken;
-    account->m_accessToken = accessToken;
-    account->m_profiles = profiles;
-
-    // Get the currently selected profile.
-    QString currentProfile = object.value("activeProfile").toString("");
-    if (!currentProfile.isEmpty())
-        account->setCurrentProfile(currentProfile);
-
-    return account;
-}
-
-MojangAccountPtr MojangAccount::createFromUsername(const QString &username)
-{
-    MojangAccountPtr account(new MojangAccount());
-    account->m_clientToken = QUuid::createUuid().toString().remove(QRegExp("[{}-]"));
-    account->m_username = username;
-    return account;
-}
-
-QJsonObject MojangAccount::saveToJson() const
-{
-    QJsonObject json;
-    json.insert("username", m_username);
-    json.insert("clientToken", m_clientToken);
-    json.insert("accessToken", m_accessToken);
-
-    QJsonArray profileArray;
-    for (AccountProfile profile : m_profiles)
-    {
-        QJsonObject profileObj;
-        profileObj.insert("id", profile.id);
-        profileObj.insert("name", profile.name);
-        profileObj.insert("legacy", profile.legacy);
-        profileArray.append(profileObj);
-    }
-    json.insert("profiles", profileArray);
-
-    QJsonObject userStructure;
-    {
-        userStructure.insert("id", m_user.id);
-        /*
-        QJsonObject userAttrs;
-        for(auto key: m_user.properties.keys())
-        {
-            auto array = QJsonArray::fromStringList(m_user.properties.values(key));
-            userAttrs.insert(key, array);
-        }
-        userStructure.insert("properties", userAttrs);
-        */
-    }
-    json.insert("user", userStructure);
-
-    if (m_currentProfile != -1)
-        json.insert("activeProfile", currentProfile()->id);
-
-    return json;
-}
-
-bool MojangAccount::setCurrentProfile(const QString &profileId)
-{
-    for (int i = 0; i < m_profiles.length(); i++)
-    {
-        if (m_profiles[i].id == profileId)
-        {
-            m_currentProfile = i;
-            return true;
-        }
-    }
-    return false;
-}
-
-const AccountProfile *MojangAccount::currentProfile() const
-{
-    if (m_currentProfile == -1)
-        return nullptr;
-    return &m_profiles[m_currentProfile];
-}
-
-AccountStatus MojangAccount::accountStatus() const
-{
-    if (m_accessToken.isEmpty())
-        return NotVerified;
-    else
-        return Verified;
-}
-
-std::shared_ptr<YggdrasilTask> MojangAccount::login(AuthSessionPtr session, QString password)
-{
-    Q_ASSERT(m_currentTask.get() == nullptr);
-
-    // take care of the true offline status
-    if (accountStatus() == NotVerified && password.isEmpty())
-    {
-        if (session)
-        {
-            session->status = AuthSession::RequiresPassword;
-            fillSession(session);
-        }
-        return nullptr;
-    }
-
-    if(accountStatus() == Verified && !session->wants_online)
-    {
-        session->status = AuthSession::PlayableOffline;
-        session->auth_server_online = false;
-        fillSession(session);
-        return nullptr;
-    }
-    else
-    {
-        if (password.isEmpty())
-        {
-            m_currentTask.reset(new RefreshTask(this));
-        }
-        else
-        {
-            m_currentTask.reset(new AuthenticateTask(this, password));
-        }
-        m_currentTask->assignSession(session);
-
-        connect(m_currentTask.get(), SIGNAL(succeeded()), SLOT(authSucceeded()));
-        connect(m_currentTask.get(), SIGNAL(failed(QString)), SLOT(authFailed(QString)));
-    }
-    return m_currentTask;
-}
-
-void MojangAccount::authSucceeded()
-{
-    auto session = m_currentTask->getAssignedSession();
-    if (session)
-    {
-        session->status =
-            session->wants_online ? AuthSession::PlayableOnline : AuthSession::PlayableOffline;
-        fillSession(session);
-        session->auth_server_online = true;
-    }
-    m_currentTask.reset();
-    emit changed();
-}
-
-void MojangAccount::authFailed(QString reason)
-{
-    auto session = m_currentTask->getAssignedSession();
-    // This is emitted when the yggdrasil tasks time out or are cancelled.
-    // -> we treat the error as no-op
-    if (m_currentTask->state() == YggdrasilTask::STATE_FAILED_SOFT)
-    {
-        if (session)
-        {
-            session->status = accountStatus() == Verified ? AuthSession::PlayableOffline
-                                                          : AuthSession::RequiresPassword;
-            session->auth_server_online = false;
-            fillSession(session);
-        }
-    }
-    else
-    {
-        m_accessToken = QString();
-        emit changed();
-        if (session)
-        {
-            session->status = AuthSession::RequiresPassword;
-            session->auth_server_online = true;
-            fillSession(session);
-        }
-    }
-    m_currentTask.reset();
-}
-
-void MojangAccount::fillSession(AuthSessionPtr session)
-{
-    // the user name. you have to have an user name
-    session->username = m_username;
-    // volatile auth token
-    session->access_token = m_accessToken;
-    // the semi-permanent client token
-    session->client_token = m_clientToken;
-    if (currentProfile())
-    {
-        // profile name
-        session->player_name = currentProfile()->name;
-        // profile ID
-        session->uuid = currentProfile()->id;
-        // 'legacy' or 'mojang', depending on account type
-        session->user_type = currentProfile()->legacy ? "legacy" : "mojang";
-        if (!session->access_token.isEmpty())
-        {
-            session->session = "token:" + m_accessToken + ":" + m_profiles[m_currentProfile].id;
-        }
-        else
-        {
-            session->session = "-";
-        }
-    }
-    else
-    {
-        session->player_name = "Player";
-        session->session = "-";
-    }
-    session->u = user();
-    session->m_accountPtr = shared_from_this();
-}
-
-void MojangAccount::decrementUses()
-{
-    Usable::decrementUses();
-    if(!isInUse())
-    {
-        emit changed();
-        qWarning() << "Account" << m_username << "is no longer in use.";
-    }
-}
-
-void MojangAccount::incrementUses()
-{
-    bool wasInUse = isInUse();
-    Usable::incrementUses();
-    if(!wasInUse)
-    {
-        emit changed();
-        qWarning() << "Account" << m_username << "is now in use.";
-    }
-}
-
-void MojangAccount::invalidateClientToken()
-{
-    m_clientToken = QUuid::createUuid().toString().remove(QRegExp("[{}-]"));
-    emit changed();
-}
diff --git a/launcher/minecraft/auth/MojangAccountList.h b/launcher/minecraft/auth/MojangAccountList.h
deleted file mode 100644
index 99d2988e..00000000
--- a/launcher/minecraft/auth/MojangAccountList.h
+++ /dev/null
@@ -1,199 +0,0 @@
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include "MojangAccount.h"
-
-#include <QObject>
-#include <QVariant>
-#include <QAbstractListModel>
-#include <QSharedPointer>
-
-/*!
- * \brief List of available Mojang accounts.
- * This should be loaded in the background by MultiMC on startup.
- *
- * This class also inherits from QAbstractListModel. Methods from that
- * class determine how this list shows up in a list view. Said methods
- * all have a default implementation, but they can be overridden by subclasses to
- * change the behavior of the list.
- */
-class MojangAccountList : public QAbstractListModel
-{
-    Q_OBJECT
-public:
-    enum ModelRoles
-    {
-        PointerRole = 0x34B1CB48
-    };
-
-    enum VListColumns
-    {
-        // TODO: Add icon column.
-
-        // First column - Active?
-        ActiveColumn = 0,
-
-        // Second column - Name
-        NameColumn,
-    };
-
-    explicit MojangAccountList(QObject *parent = 0);
-
-    //! Gets the account at the given index.
-    virtual const MojangAccountPtr at(int i) const;
-
-    //! Returns the number of accounts in the list.
-    virtual int count() const;
-
-    //////// List Model Functions ////////
-    virtual QVariant data(const QModelIndex &index, int role) const;
-    virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const;
-    virtual int rowCount(const QModelIndex &parent) const;
-    virtual int columnCount(const QModelIndex &parent) const;
-    virtual Qt::ItemFlags flags(const QModelIndex &index) const;
-    virtual bool setData(const QModelIndex &index, const QVariant &value, int role);
-
-    /*!
-     * Adds a the given Mojang account to the account list.
-     */
-    virtual void addAccount(const MojangAccountPtr account);
-
-    /*!
-     * Removes the mojang account with the given username from the account list.
-     */
-    virtual void removeAccount(const QString &username);
-
-    /*!
-     * Removes the account at the given QModelIndex.
-     */
-    virtual void removeAccount(QModelIndex index);
-
-    /*!
-     * \brief Finds an account by its username.
-     * \param The username of the account to find.
-     * \return A const pointer to the account with the given username. NULL if
-     * one doesn't exist.
-     */
-    virtual MojangAccountPtr findAccount(const QString &username) const;
-
-    /*!
-     * Sets the default path to save the list file to.
-     * If autosave is true, this list will automatically save to the given path whenever it changes.
-     * THIS FUNCTION DOES NOT LOAD THE LIST. If you set autosave, be sure to call loadList() immediately
-     * after calling this function to ensure an autosaved change doesn't overwrite the list you intended
-     * to load.
-     */
-    virtual void setListFilePath(QString path, bool autosave = false);
-
-    /*!
-     * \brief Loads the account list from the given file path.
-     * If the given file is an empty string (default), will load from the default account list file.
-     * \return True if successful, otherwise false.
-     */
-    virtual bool loadList(const QString &file = "");
-
-    /*!
-     * \brief Saves the account list to the given file.
-     * If the given file is an empty string (default), will save from the default account list file.
-     * \return True if successful, otherwise false.
-     */
-    virtual bool saveList(const QString &file = "");
-
-    /*!
-     * \brief Gets a pointer to the account that the user has selected as their "active" account.
-     * Which account is active can be overridden on a per-instance basis, but this will return the one that
-     * is set as active globally.
-     * \return The currently active MojangAccount. If there isn't an active account, returns a null pointer.
-     */
-    virtual MojangAccountPtr activeAccount() const;
-
-    /*!
-     * Sets the given account as the current active account.
-     * If the username given is an empty string, sets the active account to nothing.
-     */
-    virtual void setActiveAccount(const QString &username);
-
-    /*!
-     * Returns true if any of the account is at least Validated
-     */
-    bool anyAccountIsValid();
-
-signals:
-    /*!
-     * Signal emitted to indicate that the account list has changed.
-     * This will also fire if the value of an element in the list changes (will be implemented
-     * later).
-     */
-    void listChanged();
-
-    /*!
-     * Signal emitted to indicate that the active account has changed.
-     */
-    void activeAccountChanged();
-
-public
-slots:
-    /**
-     * This is called when one of the accounts changes and the list needs to be updated
-     */
-    void accountChanged();
-
-protected:
-    /*!
-     * Called whenever the list changes.
-     * This emits the listChanged() signal and autosaves the list (if autosave is enabled).
-     */
-    void onListChanged();
-
-    /*!
-     * Called whenever the active account changes.
-     * Emits the activeAccountChanged() signal and autosaves the list if enabled.
-     */
-    void onActiveChanged();
-
-    QList<MojangAccountPtr> m_accounts;
-
-    /*!
-     * Account that is currently active.
-     */
-    MojangAccountPtr m_activeAccount;
-
-    //! Path to the account list file. Empty string if there isn't one.
-    QString m_listFilePath;
-
-    /*!
-     * If true, the account list will automatically save to the account list path when it changes.
-     * Ignored if m_listFilePath is blank.
-     */
-    bool m_autosave = false;
-
-protected
-slots:
-    /*!
-     * Updates this list with the given list of accounts.
-     * This is done by copying each account in the given list and inserting it
-     * into this one.
-     * We need to do this so that we can set the parents of the accounts are set to this
-     * account list. This can't be done in the load task, because the accounts the load
-     * task creates are on the load task's thread and Qt won't allow their parents
-     * to be set to something created on another thread.
-     * To get around that problem, we invoke this method on the GUI thread, which
-     * then copies the accounts and sets their parents correctly.
-     * \param accounts List of accounts whose parents should be set.
-     */
-    virtual void updateListData(QList<MojangAccountPtr> versions);
-};
diff --git a/launcher/minecraft/auth-msa/context.cpp b/launcher/minecraft/auth/flows/AuthContext.cpp
index d7ecda30..9aa58ac3 100644
--- a/launcher/minecraft/auth-msa/context.cpp
+++ b/launcher/minecraft/auth/flows/AuthContext.cpp
@@ -14,9 +14,8 @@
 #include <QPixmap>
 #include <QPainter>
 
-#include "context.h"
+#include "AuthContext.h"
 #include "katabasis/Globals.h"
-#include "katabasis/StoreQSettings.h"
 #include "katabasis/Requestor.h"
 #include "BuildConfig.h"
 
@@ -24,117 +23,107 @@ using OAuth2 = Katabasis::OAuth2;
 using Requestor = Katabasis::Requestor;
 using Activity = Katabasis::Activity;
 
-Context::Context(QObject *parent) :
-    QObject(parent)
+AuthContext::AuthContext(AccountData * data, QObject *parent) :
+    AccountTask(data, parent)
 {
     mgr = new QNetworkAccessManager(this);
-
-    Katabasis::OAuth2::Options opts;
-    opts.scope = "XboxLive.signin offline_access";
-    opts.clientIdentifier = BuildConfig.CLIENT_ID;
-    opts.authorizationUrl = "https://login.live.com/oauth20_authorize.srf";
-    opts.accessTokenUrl = "https://login.live.com/oauth20_token.srf";
-    opts.listenerPorts = {28562, 28563, 28564, 28565, 28566};
-
-    oauth2 = new OAuth2(opts, m_account.msaToken, this, mgr);
-
-    connect(oauth2, &OAuth2::linkingFailed, this, &Context::onLinkingFailed);
-    connect(oauth2, &OAuth2::linkingSucceeded, this, &Context::onLinkingSucceeded);
-    connect(oauth2, &OAuth2::openBrowser, this, &Context::onOpenBrowser);
-    connect(oauth2, &OAuth2::closeBrowser, this, &Context::onCloseBrowser);
-    connect(oauth2, &OAuth2::activityChanged, this, &Context::onOAuthActivityChanged);
 }
 
-void Context::beginActivity(Activity activity) {
+void AuthContext::beginActivity(Activity activity) {
     if(isBusy()) {
         throw 0;
     }
-    activity_ = activity;
-    emit activityChanged(activity_);
+    m_activity = activity;
+    changeState(STATE_WORKING, "Initializing");
+    emit activityChanged(m_activity);
 }
 
-void Context::finishActivity() {
+void AuthContext::finishActivity() {
     if(!isBusy()) {
         throw 0;
     }
-    activity_ = Katabasis::Activity::Idle;
-    m_account.validity_ = m_account.minecraftProfile.validity;
-    emit activityChanged(activity_);
+    m_activity = Katabasis::Activity::Idle;
+    m_stage = MSAStage::Idle;
+    m_data->validity_ = m_data->minecraftProfile.validity;
+    emit activityChanged(m_activity);
 }
 
-QString Context::gameToken() {
-    return m_account.minecraftToken.token;
-}
+void AuthContext::initMSA() {
+    if(m_oauth2) {
+        return;
+    }
+    Katabasis::OAuth2::Options opts;
+    opts.scope = "XboxLive.signin offline_access";
+    opts.clientIdentifier = BuildConfig.MSA_CLIENT_ID;
+    opts.authorizationUrl = "https://login.live.com/oauth20_authorize.srf";
+    opts.accessTokenUrl = "https://login.live.com/oauth20_token.srf";
+    opts.listenerPorts = {28562, 28563, 28564, 28565, 28566};
 
-QString Context::userId() {
-    return m_account.minecraftProfile.id;
-}
+    m_oauth2 = new OAuth2(opts, m_data->msaToken, this, mgr);
 
-QString Context::userName() {
-    return m_account.minecraftProfile.name;
+    connect(m_oauth2, &OAuth2::linkingFailed, this, &AuthContext::onOAuthLinkingFailed);
+    connect(m_oauth2, &OAuth2::linkingSucceeded, this, &AuthContext::onOAuthLinkingSucceeded);
+    connect(m_oauth2, &OAuth2::openBrowser, this, &AuthContext::onOpenBrowser);
+    connect(m_oauth2, &OAuth2::closeBrowser, this, &AuthContext::onCloseBrowser);
+    connect(m_oauth2, &OAuth2::activityChanged, this, &AuthContext::onOAuthActivityChanged);
 }
 
-bool Context::silentSignIn() {
-    if(isBusy()) {
-        return false;
-    }
-    beginActivity(Activity::Refreshing);
-    if(!oauth2->refresh()) {
-        finishActivity();
-        return false;
+void AuthContext::initMojang() {
+    if(m_yggdrasil) {
+        return;
     }
+    m_yggdrasil = new Yggdrasil(m_data, this);
 
-    requestsDone = 0;
-    xboxProfileSucceeded = false;
-    mcAuthSucceeded = false;
-
-    return true;
+    connect(m_yggdrasil, &Task::failed, this, &AuthContext::onMojangFailed);
+    connect(m_yggdrasil, &Task::succeeded, this, &AuthContext::onMojangSucceeded);
 }
 
-bool Context::signIn() {
-    if(isBusy()) {
-        return false;
-    }
+void AuthContext::onMojangSucceeded() {
+    doMinecraftProfile();
+}
 
-    requestsDone = 0;
-    xboxProfileSucceeded = false;
-    mcAuthSucceeded = false;
 
-    beginActivity(Activity::LoggingIn);
-    oauth2->unlink();
-    m_account = AccountData();
-    oauth2->link();
-    return true;
+void AuthContext::onMojangFailed() {
+    finishActivity();
+    m_error = m_yggdrasil->m_error;
+    m_aborted = m_yggdrasil->m_aborted;
+    changeState(m_yggdrasil->accountState(), "Microsoft user authentication failed.");
 }
 
-bool Context::signOut() {
+/*
+bool AuthContext::signOut() {
     if(isBusy()) {
         return false;
     }
+
+    start();
+
     beginActivity(Activity::LoggingOut);
-    oauth2->unlink();
+    m_oauth2->unlink();
     m_account = AccountData();
     finishActivity();
     return true;
 }
+*/
 
-
-void Context::onOpenBrowser(const QUrl &url) {
+void AuthContext::onOpenBrowser(const QUrl &url) {
     QDesktopServices::openUrl(url);
 }
 
-void Context::onCloseBrowser() {
+void AuthContext::onCloseBrowser() {
 
 }
 
-void Context::onLinkingFailed() {
+void AuthContext::onOAuthLinkingFailed() {
     finishActivity();
+    changeState(STATE_FAILED_HARD, "Microsoft user authentication failed.");
 }
 
-void Context::onLinkingSucceeded() {
+void AuthContext::onOAuthLinkingSucceeded() {
     auto *o2t = qobject_cast<OAuth2 *>(sender());
     if (!o2t->linked()) {
         finishActivity();
+        changeState(STATE_FAILED_HARD, "Microsoft user authentication ended with an impossible state (succeeded, but not succeeded at the same time).");
         return;
     }
     QVariantMap extraTokens = o2t->extraTokens();
@@ -147,11 +136,14 @@ void Context::onLinkingSucceeded() {
     doUserAuth();
 }
 
-void Context::onOAuthActivityChanged(Katabasis::Activity activity) {
+void AuthContext::onOAuthActivityChanged(Katabasis::Activity activity) {
     // respond to activity change here
 }
 
-void Context::doUserAuth() {
+void AuthContext::doUserAuth() {
+    m_stage = MSAStage::UserAuth;
+    changeState(STATE_WORKING, "Starting user authentication");
+
     QString xbox_auth_template = R"XXX(
 {
     "Properties": {
@@ -163,15 +155,15 @@ void Context::doUserAuth() {
     "TokenType": "JWT"
 }
 )XXX";
-    auto xbox_auth_data = xbox_auth_template.arg(m_account.msaToken.token);
+    auto xbox_auth_data = xbox_auth_template.arg(m_data->msaToken.token);
 
     QNetworkRequest request = QNetworkRequest(QUrl("https://user.auth.xboxlive.com/user/authenticate"));
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     request.setRawHeader("Accept", "application/json");
-    auto *requestor = new Katabasis::Requestor(mgr, oauth2, this);
+    auto *requestor = new Katabasis::Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
 
-    connect(requestor, &Requestor::finished, this, &Context::onUserAuthDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onUserAuthDone);
     requestor->post(request, xbox_auth_data.toUtf8());
     qDebug() << "First layer of XBox auth ... commencing.";
 }
@@ -181,7 +173,7 @@ bool getDateTime(QJsonValue value, QDateTime & out) {
     if(!value.isString()) {
         return false;
     }
-    out = QDateTime::fromString(value.toString(), Qt::ISODateWithMs);
+    out = QDateTime::fromString(value.toString(), Qt::ISODate);
     return out.isValid();
 }
 
@@ -294,7 +286,7 @@ bool parseXTokenResponse(QByteArray & data, Katabasis::Token &output) {
 
 }
 
-void Context::onUserAuthDone(
+void AuthContext::onUserAuthDone(
     int requestId,
     QNetworkReply::NetworkError error,
     QByteArray replyData,
@@ -303,6 +295,7 @@ void Context::onUserAuthDone(
     if (error != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << error;
         finishActivity();
+        changeState(STATE_FAILED_HARD, "XBox user authentication failed.");
         return;
     }
 
@@ -310,9 +303,13 @@ void Context::onUserAuthDone(
     if(!parseXTokenResponse(replyData, temp)) {
         qWarning() << "Could not parse user authentication response...";
         finishActivity();
+        changeState(STATE_FAILED_HARD, "XBox user authentication response could not be understood.");
         return;
     }
-    m_account.userToken = temp;
+    m_data->userToken = temp;
+
+    m_stage = MSAStage::XboxAuth;
+    changeState(STATE_WORKING, "Starting XBox authentication");
 
     doSTSAuthMinecraft();
     doSTSAuthGeneric();
@@ -329,7 +326,7 @@ void Context::onUserAuthDone(
             },
         }
 */
-void Context::doSTSAuthMinecraft() {
+void AuthContext::doSTSAuthMinecraft() {
     QString xbox_auth_template = R"XXX(
 {
     "Properties": {
@@ -342,20 +339,20 @@ void Context::doSTSAuthMinecraft() {
     "TokenType": "JWT"
 }
 )XXX";
-    auto xbox_auth_data = xbox_auth_template.arg(m_account.userToken.token);
+    auto xbox_auth_data = xbox_auth_template.arg(m_data->userToken.token);
 
     QNetworkRequest request = QNetworkRequest(QUrl("https://xsts.auth.xboxlive.com/xsts/authorize"));
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     request.setRawHeader("Accept", "application/json");
-    Requestor *requestor = new Requestor(mgr, oauth2, this);
+    Requestor *requestor = new Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
 
-    connect(requestor, &Requestor::finished, this, &Context::onSTSAuthMinecraftDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onSTSAuthMinecraftDone);
     requestor->post(request, xbox_auth_data.toUtf8());
     qDebug() << "Second layer of XBox auth ... commencing.";
 }
 
-void Context::onSTSAuthMinecraftDone(
+void AuthContext::onSTSAuthMinecraftDone(
     int requestId,
     QNetworkReply::NetworkError error,
     QByteArray replyData,
@@ -363,29 +360,29 @@ void Context::onSTSAuthMinecraftDone(
 ) {
     if (error != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << error;
-        finishActivity();
+        m_requestsDone ++;
         return;
     }
 
     Katabasis::Token temp;
     if(!parseXTokenResponse(replyData, temp)) {
         qWarning() << "Could not parse authorization response for access to mojang services...";
-        finishActivity();
+        m_requestsDone ++;
         return;
     }
 
-    if(temp.extra["uhs"] != m_account.userToken.extra["uhs"]) {
+    if(temp.extra["uhs"] != m_data->userToken.extra["uhs"]) {
         qWarning() << "Server has changed user hash in the reply... something is wrong. ABORTING";
         qDebug() << replyData;
-        finishActivity();
+        m_requestsDone ++;
         return;
     }
-    m_account.mojangservicesToken = temp;
+    m_data->mojangservicesToken = temp;
 
     doMinecraftAuth();
 }
 
-void Context::doSTSAuthGeneric() {
+void AuthContext::doSTSAuthGeneric() {
     QString xbox_auth_template = R"XXX(
 {
     "Properties": {
@@ -398,20 +395,20 @@ void Context::doSTSAuthGeneric() {
     "TokenType": "JWT"
 }
 )XXX";
-    auto xbox_auth_data = xbox_auth_template.arg(m_account.userToken.token);
+    auto xbox_auth_data = xbox_auth_template.arg(m_data->userToken.token);
 
     QNetworkRequest request = QNetworkRequest(QUrl("https://xsts.auth.xboxlive.com/xsts/authorize"));
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     request.setRawHeader("Accept", "application/json");
-    Requestor *requestor = new Requestor(mgr, oauth2, this);
+    Requestor *requestor = new Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
 
-    connect(requestor, &Requestor::finished, this, &Context::onSTSAuthGenericDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onSTSAuthGenericDone);
     requestor->post(request, xbox_auth_data.toUtf8());
     qDebug() << "Second layer of XBox auth ... commencing.";
 }
 
-void Context::onSTSAuthGenericDone(
+void AuthContext::onSTSAuthGenericDone(
     int requestId,
     QNetworkReply::NetworkError error,
     QByteArray replyData,
@@ -419,44 +416,44 @@ void Context::onSTSAuthGenericDone(
 ) {
     if (error != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << error;
-        finishActivity();
+        m_requestsDone ++;
         return;
     }
 
     Katabasis::Token temp;
     if(!parseXTokenResponse(replyData, temp)) {
         qWarning() << "Could not parse authorization response for access to xbox API...";
-        finishActivity();
+        m_requestsDone ++;
         return;
     }
 
-    if(temp.extra["uhs"] != m_account.userToken.extra["uhs"]) {
+    if(temp.extra["uhs"] != m_data->userToken.extra["uhs"]) {
         qWarning() << "Server has changed user hash in the reply... something is wrong. ABORTING";
         qDebug() << replyData;
-        finishActivity();
+        m_requestsDone ++;
         return;
     }
-    m_account.xboxApiToken = temp;
+    m_data->xboxApiToken = temp;
 
     doXBoxProfile();
 }
 
 
-void Context::doMinecraftAuth() {
+void AuthContext::doMinecraftAuth() {
     QString mc_auth_template = R"XXX(
 {
     "identityToken": "XBL3.0 x=%1;%2"
 }
 )XXX";
-    auto data = mc_auth_template.arg(m_account.mojangservicesToken.extra["uhs"].toString(), m_account.mojangservicesToken.token);
+    auto data = mc_auth_template.arg(m_data->mojangservicesToken.extra["uhs"].toString(), m_data->mojangservicesToken.token);
 
     QNetworkRequest request = QNetworkRequest(QUrl("https://api.minecraftservices.com/authentication/login_with_xbox"));
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     request.setRawHeader("Accept", "application/json");
-    Requestor *requestor = new Requestor(mgr, oauth2, this);
+    Requestor *requestor = new Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
 
-    connect(requestor, &Requestor::finished, this, &Context::onMinecraftAuthDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onMinecraftAuthDone);
     requestor->post(request, data.toUtf8());
     qDebug() << "Getting Minecraft access token...";
 }
@@ -501,33 +498,31 @@ bool parseMojangResponse(QByteArray & data, Katabasis::Token &output) {
 }
 }
 
-void Context::onMinecraftAuthDone(
+void AuthContext::onMinecraftAuthDone(
     int requestId,
     QNetworkReply::NetworkError error,
     QByteArray replyData,
     QList<QNetworkReply::RawHeaderPair> headers
 ) {
-    requestsDone++;
+    m_requestsDone ++;
 
     if (error != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << error;
         qDebug() << replyData;
-        finishActivity();
         return;
     }
 
-    if(!parseMojangResponse(replyData, m_account.minecraftToken)) {
+    if(!parseMojangResponse(replyData, m_data->yggdrasilToken)) {
         qWarning() << "Could not parse login_with_xbox response...";
         qDebug() << replyData;
-        finishActivity();
         return;
     }
-    mcAuthSucceeded = true;
+    m_mcAuthSucceeded = true;
 
     checkResult();
 }
 
-void Context::doXBoxProfile() {
+void AuthContext::doXBoxProfile() {
     auto url = QUrl("https://profile.xboxlive.com/users/me/profile/settings");
     QUrlQuery q;
     q.addQueryItem(
@@ -544,45 +539,45 @@ void Context::doXBoxProfile() {
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     request.setRawHeader("Accept", "application/json");
     request.setRawHeader("x-xbl-contract-version", "3");
-    request.setRawHeader("Authorization", QString("XBL3.0 x=%1;%2").arg(m_account.userToken.extra["uhs"].toString(), m_account.xboxApiToken.token).toUtf8());
-    Requestor *requestor = new Requestor(mgr, oauth2, this);
+    request.setRawHeader("Authorization", QString("XBL3.0 x=%1;%2").arg(m_data->userToken.extra["uhs"].toString(), m_data->xboxApiToken.token).toUtf8());
+    Requestor *requestor = new Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
 
-    connect(requestor, &Requestor::finished, this, &Context::onXBoxProfileDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onXBoxProfileDone);
     requestor->get(request);
     qDebug() << "Getting Xbox profile...";
 }
 
-void Context::onXBoxProfileDone(
+void AuthContext::onXBoxProfileDone(
     int requestId,
     QNetworkReply::NetworkError error,
     QByteArray replyData,
     QList<QNetworkReply::RawHeaderPair> headers
 ) {
-    requestsDone ++;
+    m_requestsDone ++;
 
     if (error != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << error;
         qDebug() << replyData;
-        finishActivity();
         return;
     }
 
     qDebug() << "XBox profile: " << replyData;
 
-    xboxProfileSucceeded = true;
+    m_xboxProfileSucceeded = true;
     checkResult();
 }
 
-void Context::checkResult() {
-    if(requestsDone != 2) {
+void AuthContext::checkResult() {
+    if(m_requestsDone != 2) {
         return;
     }
-    if(mcAuthSucceeded && xboxProfileSucceeded) {
+    if(m_mcAuthSucceeded && m_xboxProfileSucceeded) {
         doMinecraftProfile();
     }
     else {
         finishActivity();
+        changeState(STATE_FAILED_HARD, "XBox and/or Mojang authentication steps did not succeed");
     }
 }
 
@@ -666,273 +661,92 @@ bool parseMinecraftProfile(QByteArray & data, MinecraftProfile &output) {
 }
 }
 
-void Context::doMinecraftProfile() {
+void AuthContext::doMinecraftProfile() {
+    m_stage = MSAStage::MinecraftProfile;
+    changeState(STATE_WORKING, "Starting minecraft profile acquisition");
+
     auto url = QUrl("https://api.minecraftservices.com/minecraft/profile");
     QNetworkRequest request = QNetworkRequest(url);
     request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
     // request.setRawHeader("Accept", "application/json");
-    request.setRawHeader("Authorization", QString("Bearer %1").arg(m_account.minecraftToken.token).toUtf8());
+    request.setRawHeader("Authorization", QString("Bearer %1").arg(m_data->yggdrasilToken.token).toUtf8());
 
-    Requestor *requestor = new Requestor(mgr, oauth2, this);
+    Requestor *requestor = new Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
 
-    connect(requestor, &Requestor::finished, this, &Context::onMinecraftProfileDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onMinecraftProfileDone);
     requestor->get(request);
 }
 
-void Context::onMinecraftProfileDone(int, QNetworkReply::NetworkError error, QByteArray data, QList<QNetworkReply::RawHeaderPair> headers) {
+void AuthContext::onMinecraftProfileDone(int, QNetworkReply::NetworkError error, QByteArray data, QList<QNetworkReply::RawHeaderPair> headers) {
     qDebug() << data;
     if (error == QNetworkReply::ContentNotFoundError) {
-        m_account.minecraftProfile = MinecraftProfile();
+        m_data->minecraftProfile = MinecraftProfile();
         finishActivity();
+        changeState(STATE_FAILED_HARD, "Account is missing a profile");
         return;
     }
     if (error != QNetworkReply::NoError) {
         finishActivity();
+        changeState(STATE_FAILED_HARD, "Profile acquisition failed");
         return;
     }
-    if(!parseMinecraftProfile(data, m_account.minecraftProfile)) {
-        m_account.minecraftProfile = MinecraftProfile();
+    if(!parseMinecraftProfile(data, m_data->minecraftProfile)) {
+        m_data->minecraftProfile = MinecraftProfile();
         finishActivity();
+        changeState(STATE_FAILED_HARD, "Profile response could not be parsed");
         return;
     }
     doGetSkin();
 }
 
-void Context::doGetSkin() {
-    auto url = QUrl(m_account.minecraftProfile.skin.url);
+void AuthContext::doGetSkin() {
+    m_stage = MSAStage::Skin;
+    changeState(STATE_WORKING, "Starting skin acquisition");
+
+    auto url = QUrl(m_data->minecraftProfile.skin.url);
     QNetworkRequest request = QNetworkRequest(url);
-    Requestor *requestor = new Requestor(mgr, oauth2, this);
+    Requestor *requestor = new Requestor(mgr, m_oauth2, this);
     requestor->setAddAccessTokenInQuery(false);
-    connect(requestor, &Requestor::finished, this, &Context::onSkinDone);
+    connect(requestor, &Requestor::finished, this, &AuthContext::onSkinDone);
     requestor->get(request);
 }
 
-void Context::onSkinDone(int, QNetworkReply::NetworkError error, QByteArray data, QList<QNetworkReply::RawHeaderPair>) {
+void AuthContext::onSkinDone(int, QNetworkReply::NetworkError error, QByteArray data, QList<QNetworkReply::RawHeaderPair>) {
     if (error == QNetworkReply::NoError) {
-        m_account.minecraftProfile.skin.data = data;
+        m_data->minecraftProfile.skin.data = data;
     }
+    m_data->validity_ = Katabasis::Validity::Certain;
     finishActivity();
+    changeState(STATE_SUCCEEDED, "Finished whole chain");
 }
 
-namespace {
-void tokenToJSON(QJsonObject &parent, Katabasis::Token t, const char * tokenName) {
-    if(t.validity == Katabasis::Validity::None || !t.persistent) {
-        return;
-    }
-    QJsonObject out;
-    if(t.issueInstant.isValid()) {
-        out["iat"] = QJsonValue(t.issueInstant.toSecsSinceEpoch());
-    }
-
-    if(t.notAfter.isValid()) {
-        out["exp"] = QJsonValue(t.notAfter.toSecsSinceEpoch());
-    }
-
-    if(!t.token.isEmpty()) {
-        out["token"] = QJsonValue(t.token);
-    }
-    if(!t.refresh_token.isEmpty()) {
-        out["refresh_token"] = QJsonValue(t.refresh_token);
-    }
-    if(t.extra.size()) {
-        out["extra"] = QJsonObject::fromVariantMap(t.extra);
-    }
-    if(out.size()) {
-        parent[tokenName] = out;
-    }
-}
-
-Katabasis::Token tokenFromJSON(const QJsonObject &parent, const char * tokenName) {
-    Katabasis::Token out;
-    auto tokenObject = parent.value(tokenName).toObject();
-    if(tokenObject.isEmpty()) {
-        return out;
-    }
-    auto issueInstant = tokenObject.value("iat");
-    if(issueInstant.isDouble()) {
-        out.issueInstant = QDateTime::fromSecsSinceEpoch((int64_t) issueInstant.toDouble());
-    }
-
-    auto notAfter = tokenObject.value("exp");
-    if(notAfter.isDouble()) {
-        out.notAfter = QDateTime::fromSecsSinceEpoch((int64_t) notAfter.toDouble());
-    }
-
-    auto token = tokenObject.value("token");
-    if(token.isString()) {
-        out.token = token.toString();
-        out.validity = Katabasis::Validity::Assumed;
-    }
-
-    auto refresh_token = tokenObject.value("refresh_token");
-    if(refresh_token.isString()) {
-        out.refresh_token = refresh_token.toString();
-    }
-
-    auto extra = tokenObject.value("extra");
-    if(extra.isObject()) {
-        out.extra = extra.toObject().toVariantMap();
-    }
-    return out;
-}
-
-void profileToJSON(QJsonObject &parent, MinecraftProfile p, const char * tokenName) {
-    if(p.id.isEmpty()) {
-        return;
-    }
-    QJsonObject out;
-    out["id"] = QJsonValue(p.id);
-    out["name"] = QJsonValue(p.name);
-    if(p.currentCape != -1) {
-        out["cape"] = p.capes[p.currentCape].id;
-    }
-
-    {
-        QJsonObject skinObj;
-        skinObj["id"] = p.skin.id;
-        skinObj["url"] = p.skin.url;
-        skinObj["variant"] = p.skin.variant;
-        if(p.skin.data.size()) {
-            skinObj["data"] = QString::fromLatin1(p.skin.data.toBase64());
-        }
-        out["skin"] = skinObj;
-    }
-
-    QJsonArray capesArray;
-    for(auto & cape: p.capes) {
-        QJsonObject capeObj;
-        capeObj["id"] = cape.id;
-        capeObj["url"] = cape.url;
-        capeObj["alias"] = cape.alias;
-        if(cape.data.size()) {
-            capeObj["data"] = QString::fromLatin1(cape.data.toBase64());
-        }
-        capesArray.push_back(capeObj);
-    }
-    out["capes"] = capesArray;
-    parent[tokenName] = out;
-}
-
-MinecraftProfile profileFromJSON(const QJsonObject &parent, const char * tokenName) {
-    MinecraftProfile out;
-    auto tokenObject = parent.value(tokenName).toObject();
-    if(tokenObject.isEmpty()) {
-        return out;
-    }
-    {
-        auto idV = tokenObject.value("id");
-        auto nameV = tokenObject.value("name");
-        if(!idV.isString() || !nameV.isString()) {
-            qWarning() << "mandatory profile attributes are missing or of unexpected type";
-            return MinecraftProfile();
-        }
-        out.name = nameV.toString();
-        out.id = idV.toString();
-    }
-
+QString AuthContext::getStateMessage() const {
+    switch (m_accountState)
     {
-        auto skinV = tokenObject.value("skin");
-        if(!skinV.isObject()) {
-            qWarning() << "skin is missing";
-            return MinecraftProfile();
-        }
-        auto skinObj = skinV.toObject();
-        auto idV = skinObj.value("id");
-        auto urlV = skinObj.value("url");
-        auto variantV = skinObj.value("variant");
-        if(!idV.isString() || !urlV.isString() || !variantV.isString()) {
-            qWarning() << "mandatory skin attributes are missing or of unexpected type";
-            return MinecraftProfile();
-        }
-        out.skin.id = idV.toString();
-        out.skin.url = urlV.toString();
-        out.skin.variant = variantV.toString();
-
-        // data for skin is optional
-        auto dataV = skinObj.value("data");
-        if(dataV.isString()) {
-            // TODO: validate base64
-            out.skin.data = QByteArray::fromBase64(dataV.toString().toLatin1());
-        }
-        else if (!dataV.isUndefined()) {
-            qWarning() << "skin data is something unexpected";
-            return MinecraftProfile();
-        }
-    }
-
-    auto capesV = tokenObject.value("capes");
-    if(!capesV.isArray()) {
-        qWarning() << "capes is not an array!";
-        return MinecraftProfile();
-    }
-    auto capesArray = capesV.toArray();
-    for(auto capeV: capesArray) {
-        if(!capeV.isObject()) {
-            qWarning() << "cape is not an object!";
-            return MinecraftProfile();
-        }
-        auto capeObj = capeV.toObject();
-        auto idV = capeObj.value("id");
-        auto urlV = capeObj.value("url");
-        auto aliasV = capeObj.value("alias");
-        if(!idV.isString() || !urlV.isString() || !aliasV.isString()) {
-            qWarning() << "mandatory skin attributes are missing or of unexpected type";
-            return MinecraftProfile();
-        }
-        Cape cape;
-        cape.id = idV.toString();
-        cape.url = urlV.toString();
-        cape.alias = aliasV.toString();
-
-        // data for cape is optional.
-        auto dataV = capeObj.value("data");
-        if(dataV.isString()) {
-            // TODO: validate base64
-            cape.data = QByteArray::fromBase64(dataV.toString().toLatin1());
-        }
-        else if (!dataV.isUndefined()) {
-            qWarning() << "cape data is something unexpected";
-            return MinecraftProfile();
-        }
-        out.capes.push_back(cape);
-    }
-    out.validity = Katabasis::Validity::Assumed;
-    return out;
-}
-
-}
-
-bool Context::resumeFromState(QByteArray data) {
-    QJsonParseError error;
-    auto doc = QJsonDocument::fromJson(data, &error);
-    if(error.error != QJsonParseError::NoError) {
-        qWarning() << "Failed to parse account data as JSON.";
-        return false;
+        case STATE_WORKING:
+            switch(m_stage) {
+                case MSAStage::Idle: {
+                    QString loginMessage = tr("Logging in as %1 user");
+                    if(m_data->type == AccountType::MSA) {
+                        return loginMessage.arg("Microsoft");
+                    }
+                    else {
+                        return loginMessage.arg("Mojang");
+                    }
+                }
+                case MSAStage::UserAuth:
+                    return tr("Logging in as XBox user");
+                case MSAStage::XboxAuth:
+                    return tr("Logging in with XBox and Mojang services");
+                case MSAStage::MinecraftProfile:
+                    return tr("Getting Minecraft profile");
+                case MSAStage::Skin:
+                    return tr("Getting Minecraft skin");
+                default:
+                    break;
+            }
+        default:
+            return AccountTask::getStateMessage();
     }
-    auto docObject = doc.object();
-    m_account.msaToken = tokenFromJSON(docObject, "msa");
-    m_account.userToken = tokenFromJSON(docObject, "utoken");
-    m_account.xboxApiToken = tokenFromJSON(docObject, "xrp-main");
-    m_account.mojangservicesToken = tokenFromJSON(docObject, "xrp-mc");
-    m_account.minecraftToken = tokenFromJSON(docObject, "ygg");
-
-    m_account.minecraftProfile = profileFromJSON(docObject, "profile");
-
-    m_account.validity_ = m_account.minecraftProfile.validity;
-
-    return true;
-}
-
-QByteArray Context::saveState() {
-    QJsonDocument doc;
-    QJsonObject output;
-    tokenToJSON(output, m_account.msaToken, "msa");
-    tokenToJSON(output, m_account.userToken, "utoken");
-    tokenToJSON(output, m_account.xboxApiToken, "xrp-main");
-    tokenToJSON(output, m_account.mojangservicesToken, "xrp-mc");
-    tokenToJSON(output, m_account.minecraftToken, "ygg");
-    profileToJSON(output, m_account.minecraftProfile, "profile");
-    doc.setObject(output);
-    return doc.toJson(QJsonDocument::Indented);
 }
diff --git a/launcher/minecraft/auth-msa/context.h b/launcher/minecraft/auth/flows/AuthContext.h
index f1ac99b8..5f99dba3 100644
--- a/launcher/minecraft/auth-msa/context.h
+++ b/launcher/minecraft/auth/flows/AuthContext.h
@@ -7,87 +7,47 @@
 #include <QImage>
 
 #include <katabasis/OAuth2.h>
+#include "Yggdrasil.h"
+#include "../AccountData.h"
+#include "../AccountTask.h"
 
-struct Skin {
-    QString id;
-    QString url;
-    QString variant;
-
-    QByteArray data;
-};
-
-struct Cape {
-    QString id;
-    QString url;
-    QString alias;
-
-    QByteArray data;
-};
-
-struct MinecraftProfile  {
-    QString id;
-    QString name;
-    Skin skin;
-    int currentCape = -1;
-    QVector<Cape> capes;
-    Katabasis::Validity validity = Katabasis::Validity::None;
-};
-
-enum class AccountType {
-    MSA,
-    Mojang
-};
-
-struct AccountData {
-    AccountType type = AccountType::MSA;
-
-    Katabasis::Token msaToken;
-    Katabasis::Token userToken;
-    Katabasis::Token xboxApiToken;
-    Katabasis::Token mojangservicesToken;
-    Katabasis::Token minecraftToken;
-
-    MinecraftProfile minecraftProfile;
-    Katabasis::Validity validity_ = Katabasis::Validity::None;
-};
-
-class Context : public QObject
+class AuthContext : public AccountTask
 {
     Q_OBJECT
 
 public:
-    explicit Context(QObject *parent = 0);
-
-    QByteArray saveState();
-    bool resumeFromState(QByteArray data);
+    explicit AuthContext(AccountData * data, QObject *parent = 0);
 
     bool isBusy() {
-        return activity_ != Katabasis::Activity::Idle;
+        return m_activity != Katabasis::Activity::Idle;
     };
     Katabasis::Validity validity() {
-        return m_account.validity_;
+        return m_data->validity_;
     };
 
-    bool signIn();
-    bool silentSignIn();
-    bool signOut();
+    //bool signOut();
+
+    QString getStateMessage() const override;
 
-    QString userName();
-    QString userId();
-    QString gameToken();
 signals:
-    void succeeded();
-    void failed();
     void activityChanged(Katabasis::Activity activity);
 
 private slots:
-    void onLinkingSucceeded();
-    void onLinkingFailed();
+// OAuth-specific callbacks
+    void onOAuthLinkingSucceeded();
+    void onOAuthLinkingFailed();
     void onOpenBrowser(const QUrl &url);
     void onCloseBrowser();
     void onOAuthActivityChanged(Katabasis::Activity activity);
 
-private:
+// Yggdrasil specific callbacks
+    void onMojangSucceeded();
+    void onMojangFailed();
+
+protected:
+    void initMSA();
+    void initMojang();
+
     void doUserAuth();
     Q_SLOT void onUserAuthDone(int, QNetworkReply::NetworkError, QByteArray, QList<QNetworkReply::RawHeaderPair>);
 
@@ -109,20 +69,26 @@ private:
 
     void checkResult();
 
-private:
+protected:
     void beginActivity(Katabasis::Activity activity);
     void finishActivity();
     void clearTokens();
 
-private:
-    Katabasis::OAuth2 *oauth2 = nullptr;
-
-    int requestsDone = 0;
-    bool xboxProfileSucceeded = false;
-    bool mcAuthSucceeded = false;
-    Katabasis::Activity activity_ = Katabasis::Activity::Idle;
-
-    AccountData m_account;
+protected:
+    Katabasis::OAuth2 *m_oauth2 = nullptr;
+    Yggdrasil *m_yggdrasil = nullptr;
+
+    int m_requestsDone = 0;
+    bool m_xboxProfileSucceeded = false;
+    bool m_mcAuthSucceeded = false;
+    Katabasis::Activity m_activity = Katabasis::Activity::Idle;
+    enum class MSAStage {
+        Idle,
+        UserAuth,
+        XboxAuth,
+        MinecraftProfile,
+        Skin
+    } m_stage = MSAStage::Idle;
 
     QNetworkAccessManager *mgr = nullptr;
 };
diff --git a/launcher/minecraft/auth/flows/AuthenticateTask.cpp b/launcher/minecraft/auth/flows/AuthenticateTask.cpp
deleted file mode 100644
index 2e8dc859..00000000
--- a/launcher/minecraft/auth/flows/AuthenticateTask.cpp
+++ /dev/null
@@ -1,202 +0,0 @@
-
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "AuthenticateTask.h"
-#include "../MojangAccount.h"
-
-#include <QJsonDocument>
-#include <QJsonObject>
-#include <QJsonArray>
-#include <QVariant>
-
-#include <QDebug>
-#include <QUuid>
-
-AuthenticateTask::AuthenticateTask(MojangAccount * account, const QString &password,
-                                   QObject *parent)
-    : YggdrasilTask(account, parent), m_password(password)
-{
-}
-
-QJsonObject AuthenticateTask::getRequestContent() const
-{
-    /*
-     * {
-     *   "agent": {                                // optional
-     *   "name": "Minecraft",                    // So far this is the only encountered value
-     *   "version": 1                            // This number might be increased
-     *                                             // by the vanilla client in the future
-     *   },
-     *   "username": "mojang account name",        // Can be an email address or player name for
-                                                // unmigrated accounts
-     *  "password": "mojang account password",
-     *  "clientToken": "client identifier"        // optional
-     *  "requestUser": true/false               // request the user structure
-     * }
-     */
-    QJsonObject req;
-
-    {
-        QJsonObject agent;
-        // C++ makes string literals void* for some stupid reason, so we have to tell it
-        // QString... Thanks Obama.
-        agent.insert("name", QString("Minecraft"));
-        agent.insert("version", 1);
-        req.insert("agent", agent);
-    }
-
-    req.insert("username", m_account->username());
-    req.insert("password", m_password);
-    req.insert("requestUser", true);
-
-    // If we already have a client token, give it to the server.
-    // Otherwise, let the server give us one.
-
-    if(m_account->m_clientToken.isEmpty())
-    {
-        auto uuid = QUuid::createUuid();
-        auto uuidString = uuid.toString().remove('{').remove('-').remove('}');
-        m_account->m_clientToken = uuidString;
-    }
-    req.insert("clientToken", m_account->m_clientToken);
-
-    return req;
-}
-
-void AuthenticateTask::processResponse(QJsonObject responseData)
-{
-    // Read the response data. We need to get the client token, access token, and the selected
-    // profile.
-    qDebug() << "Processing authentication response.";
-    // qDebug() << responseData;
-    // If we already have a client token, make sure the one the server gave us matches our
-    // existing one.
-    qDebug() << "Getting client token.";
-    QString clientToken = responseData.value("clientToken").toString("");
-    if (clientToken.isEmpty())
-    {
-        // Fail if the server gave us an empty client token
-        changeState(STATE_FAILED_HARD, tr("Authentication server didn't send a client token."));
-        return;
-    }
-    if (!m_account->m_clientToken.isEmpty() && clientToken != m_account->m_clientToken)
-    {
-        changeState(STATE_FAILED_HARD, tr("Authentication server attempted to change the client token. This isn't supported."));
-        return;
-    }
-    // Set the client token.
-    m_account->m_clientToken = clientToken;
-
-    // Now, we set the access token.
-    qDebug() << "Getting access token.";
-    QString accessToken = responseData.value("accessToken").toString("");
-    if (accessToken.isEmpty())
-    {
-        // Fail if the server didn't give us an access token.
-        changeState(STATE_FAILED_HARD, tr("Authentication server didn't send an access token."));
-        return;
-    }
-    // Set the access token.
-    m_account->m_accessToken = accessToken;
-
-    // Now we load the list of available profiles.
-    // Mojang hasn't yet implemented the profile system,
-    // but we might as well support what's there so we
-    // don't have trouble implementing it later.
-    qDebug() << "Loading profile list.";
-    QJsonArray availableProfiles = responseData.value("availableProfiles").toArray();
-    QList<AccountProfile> loadedProfiles;
-    for (auto iter : availableProfiles)
-    {
-        QJsonObject profile = iter.toObject();
-        // Profiles are easy, we just need their ID and name.
-        QString id = profile.value("id").toString("");
-        QString name = profile.value("name").toString("");
-        bool legacy = profile.value("legacy").toBool(false);
-
-        if (id.isEmpty() || name.isEmpty())
-        {
-            // This should never happen, but we might as well
-            // warn about it if it does so we can debug it easily.
-            // You never know when Mojang might do something truly derpy.
-            qWarning() << "Found entry in available profiles list with missing ID or name "
-                           "field. Ignoring it.";
-        }
-
-        // Now, add a new AccountProfile entry to the list.
-        loadedProfiles.append({id, name, legacy});
-    }
-    // Put the list of profiles we loaded into the MojangAccount object.
-    m_account->m_profiles = loadedProfiles;
-
-    // Finally, we set the current profile to the correct value. This is pretty simple.
-    // We do need to make sure that the current profile that the server gave us
-    // is actually in the available profiles list.
-    // If it isn't, we'll just fail horribly (*shouldn't* ever happen, but you never know).
-    qDebug() << "Setting current profile.";
-    QJsonObject currentProfile = responseData.value("selectedProfile").toObject();
-    QString currentProfileId = currentProfile.value("id").toString("");
-    if (currentProfileId.isEmpty())
-    {
-        changeState(STATE_FAILED_HARD, tr("Authentication server didn't specify a currently selected profile. The account exists, but likely isn't premium."));
-        return;
-    }
-    if (!m_account->setCurrentProfile(currentProfileId))
-    {
-        changeState(STATE_FAILED_HARD, tr("Authentication server specified a selected profile that wasn't in the available profiles list."));
-        return;
-    }
-
-    // this is what the vanilla launcher passes to the userProperties launch param
-    if (responseData.contains("user"))
-    {
-        User u;
-        auto obj = responseData.value("user").toObject();
-        u.id = obj.value("id").toString();
-        auto propArray = obj.value("properties").toArray();
-        for (auto prop : propArray)
-        {
-            auto propTuple = prop.toObject();
-            auto name = propTuple.value("name").toString();
-            auto value = propTuple.value("value").toString();
-            u.properties.insert(name, value);
-        }
-        m_account->m_user = u;
-    }
-
-    // We've made it through the minefield of possible errors. Return true to indicate that
-    // we've succeeded.
-    qDebug() << "Finished reading authentication response.";
-    changeState(STATE_SUCCEEDED);
-}
-
-QString AuthenticateTask::getEndpoint() const
-{
-    return "authenticate";
-}
-
-QString AuthenticateTask::getStateMessage() const
-{
-    switch (m_state)
-    {
-    case STATE_SENDING_REQUEST:
-        return tr("Authenticating: Sending request...");
-    case STATE_PROCESSING_RESPONSE:
-        return tr("Authenticating: Processing response...");
-    default:
-        return YggdrasilTask::getStateMessage();
-    }
-}
diff --git a/launcher/minecraft/auth/flows/AuthenticateTask.h b/launcher/minecraft/auth/flows/AuthenticateTask.h
deleted file mode 100644
index 4c14eec7..00000000
--- a/launcher/minecraft/auth/flows/AuthenticateTask.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include "../YggdrasilTask.h"
-
-#include <QObject>
-#include <QString>
-#include <QJsonObject>
-
-/**
- * The authenticate task takes a MojangAccount with no access token and password and attempts to
- * authenticate with Mojang's servers.
- * If successful, it will set the MojangAccount's access token.
- */
-class AuthenticateTask : public YggdrasilTask
-{
-    Q_OBJECT
-public:
-    AuthenticateTask(MojangAccount *account, const QString &password, QObject *parent = 0);
-
-protected:
-    virtual QJsonObject getRequestContent() const override;
-
-    virtual QString getEndpoint() const override;
-
-    virtual void processResponse(QJsonObject responseData) override;
-
-    virtual QString getStateMessage() const override;
-
-private:
-    QString m_password;
-};
diff --git a/launcher/minecraft/auth/flows/MSAHelper.txt b/launcher/minecraft/auth/flows/MSAHelper.txt
new file mode 100644
index 00000000..dfaec374
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MSAHelper.txt
@@ -0,0 +1,51 @@
+class Helper : public QObject {
+    Q_OBJECT
+
+public:
+    Helper(MSAFlows * context) : QObject(), context_(context), msg_(QString()) {
+        QFile tokenCache("usercache.dat");
+        if(tokenCache.open(QIODevice::ReadOnly)) {
+            context_->resumeFromState(tokenCache.readAll());
+        }
+    }
+
+public slots:
+    void run() {
+        connect(context_, &MSAFlows::activityChanged, this, &Helper::onActivityChanged);
+        context_->silentSignIn();
+    }
+
+    void onFailed() {
+        qDebug() << "Login failed";
+    }
+
+    void onActivityChanged(Katabasis::Activity activity) {
+        if(activity == Katabasis::Activity::Idle) {
+            switch(context_->validity()) {
+                case Katabasis::Validity::None: {
+                    // account is gone, remove it.
+                    QFile::remove("usercache.dat");
+                }
+                break;
+                case Katabasis::Validity::Assumed: {
+                    // this is basically a soft-failed refresh. do nothing.
+                }
+                break;
+                case Katabasis::Validity::Certain: {
+                    // stuff got refreshed / signed in. Save.
+                    auto data = context_->saveState();
+                    QSaveFile tokenCache("usercache.dat");
+                    if(tokenCache.open(QIODevice::WriteOnly)) {
+                        tokenCache.write(context_->saveState());
+                        tokenCache.commit();
+                    }
+                }
+                break;
+            }
+        }
+    }
+
+private:
+    MSAFlows *context_;
+    QString msg_;
+};
diff --git a/launcher/minecraft/auth/flows/MSAInteractive.cpp b/launcher/minecraft/auth/flows/MSAInteractive.cpp
new file mode 100644
index 00000000..03beb279
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MSAInteractive.cpp
@@ -0,0 +1,20 @@
+#include "MSAInteractive.h"
+
+MSAInteractive::MSAInteractive(AccountData* data, QObject* parent) : AuthContext(data, parent) {}
+
+void MSAInteractive::executeTask() {
+    m_requestsDone = 0;
+    m_xboxProfileSucceeded = false;
+    m_mcAuthSucceeded = false;
+
+    initMSA();
+
+    QVariantMap extraOpts;
+    extraOpts["prompt"] = "select_account";
+    m_oauth2->setExtraRequestParams(extraOpts);
+
+    beginActivity(Katabasis::Activity::LoggingIn);
+    m_oauth2->unlink();
+    *m_data = AccountData();
+    m_oauth2->link();
+}
diff --git a/launcher/minecraft/auth/flows/MSAInteractive.h b/launcher/minecraft/auth/flows/MSAInteractive.h
new file mode 100644
index 00000000..9556f254
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MSAInteractive.h
@@ -0,0 +1,10 @@
+#pragma once
+#include "AuthContext.h"
+
+class MSAInteractive : public AuthContext
+{
+    Q_OBJECT
+public:
+    explicit MSAInteractive(AccountData * data, QObject *parent = 0);
+    void executeTask() override;
+};
diff --git a/launcher/minecraft/auth/flows/MSASilent.cpp b/launcher/minecraft/auth/flows/MSASilent.cpp
new file mode 100644
index 00000000..8ce43c1f
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MSASilent.cpp
@@ -0,0 +1,16 @@
+#include "MSASilent.h"
+
+MSASilent::MSASilent(AccountData* data, QObject* parent) : AuthContext(data, parent) {}
+
+void MSASilent::executeTask() {
+    m_requestsDone = 0;
+    m_xboxProfileSucceeded = false;
+    m_mcAuthSucceeded = false;
+
+    initMSA();
+
+    beginActivity(Katabasis::Activity::Refreshing);
+    if(!m_oauth2->refresh()) {
+        finishActivity();
+    }
+}
diff --git a/launcher/minecraft/auth/flows/MSASilent.h b/launcher/minecraft/auth/flows/MSASilent.h
new file mode 100644
index 00000000..e1b3d43d
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MSASilent.h
@@ -0,0 +1,10 @@
+#pragma once
+#include "AuthContext.h"
+
+class MSASilent : public AuthContext
+{
+    Q_OBJECT
+public:
+    explicit MSASilent(AccountData * data, QObject *parent = 0);
+    void executeTask() override;
+};
diff --git a/launcher/minecraft/auth/flows/MojangLogin.cpp b/launcher/minecraft/auth/flows/MojangLogin.cpp
new file mode 100644
index 00000000..cca911b5
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MojangLogin.cpp
@@ -0,0 +1,14 @@
+#include "MojangLogin.h"
+
+MojangLogin::MojangLogin(AccountData* data, QString password, QObject* parent) : AuthContext(data, parent), m_password(password) {}
+
+void MojangLogin::executeTask() {
+    m_requestsDone = 0;
+    m_xboxProfileSucceeded = false;
+    m_mcAuthSucceeded = false;
+
+    initMojang();
+
+    beginActivity(Katabasis::Activity::LoggingIn);
+    m_yggdrasil->login(m_password);
+}
diff --git a/launcher/minecraft/auth/flows/MojangLogin.h b/launcher/minecraft/auth/flows/MojangLogin.h
new file mode 100644
index 00000000..2e765ae8
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MojangLogin.h
@@ -0,0 +1,13 @@
+#pragma once
+#include "AuthContext.h"
+
+class MojangLogin : public AuthContext
+{
+    Q_OBJECT
+public:
+    explicit MojangLogin(AccountData * data, QString password, QObject *parent = 0);
+    void executeTask() override;
+
+private:
+    QString m_password;
+};
diff --git a/launcher/minecraft/auth/flows/MojangRefresh.cpp b/launcher/minecraft/auth/flows/MojangRefresh.cpp
new file mode 100644
index 00000000..af99175c
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MojangRefresh.cpp
@@ -0,0 +1,14 @@
+#include "MojangRefresh.h"
+
+MojangRefresh::MojangRefresh(AccountData* data, QObject* parent) : AuthContext(data, parent) {}
+
+void MojangRefresh::executeTask() {
+    m_requestsDone = 0;
+    m_xboxProfileSucceeded = false;
+    m_mcAuthSucceeded = false;
+
+    initMojang();
+
+    beginActivity(Katabasis::Activity::Refreshing);
+    m_yggdrasil->refresh();
+}
diff --git a/launcher/minecraft/auth/flows/MojangRefresh.h b/launcher/minecraft/auth/flows/MojangRefresh.h
new file mode 100644
index 00000000..fb4facd5
--- /dev/null
+++ b/launcher/minecraft/auth/flows/MojangRefresh.h
@@ -0,0 +1,10 @@
+#pragma once
+#include "AuthContext.h"
+
+class MojangRefresh : public AuthContext
+{
+    Q_OBJECT
+public:
+    explicit MojangRefresh(AccountData * data, QObject *parent = 0);
+    void executeTask() override;
+};
diff --git a/launcher/minecraft/auth/flows/RefreshTask.cpp b/launcher/minecraft/auth/flows/RefreshTask.cpp
deleted file mode 100644
index ecba178d..00000000
--- a/launcher/minecraft/auth/flows/RefreshTask.cpp
+++ /dev/null
@@ -1,144 +0,0 @@
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "RefreshTask.h"
-#include "../MojangAccount.h"
-
-#include <QJsonDocument>
-#include <QJsonObject>
-#include <QJsonArray>
-#include <QVariant>
-
-#include <QDebug>
-
-RefreshTask::RefreshTask(MojangAccount *account) : YggdrasilTask(account)
-{
-}
-
-QJsonObject RefreshTask::getRequestContent() const
-{
-    /*
-     * {
-     *  "clientToken": "client identifier"
-     *  "accessToken": "current access token to be refreshed"
-     *  "selectedProfile":                      // specifying this causes errors
-     *  {
-     *   "id": "profile ID"
-     *   "name": "profile name"
-     *  }
-     *  "requestUser": true/false               // request the user structure
-     * }
-     */
-    QJsonObject req;
-    req.insert("clientToken", m_account->m_clientToken);
-    req.insert("accessToken", m_account->m_accessToken);
-    /*
-    {
-        auto currentProfile = m_account->currentProfile();
-        QJsonObject profile;
-        profile.insert("id", currentProfile->id());
-        profile.insert("name", currentProfile->name());
-        req.insert("selectedProfile", profile);
-    }
-    */
-    req.insert("requestUser", true);
-
-    return req;
-}
-
-void RefreshTask::processResponse(QJsonObject responseData)
-{
-    // Read the response data. We need to get the client token, access token, and the selected
-    // profile.
-    qDebug() << "Processing authentication response.";
-
-    // qDebug() << responseData;
-    // If we already have a client token, make sure the one the server gave us matches our
-    // existing one.
-    QString clientToken = responseData.value("clientToken").toString("");
-    if (clientToken.isEmpty())
-    {
-        // Fail if the server gave us an empty client token
-        changeState(STATE_FAILED_HARD, tr("Authentication server didn't send a client token."));
-        return;
-    }
-    if (!m_account->m_clientToken.isEmpty() && clientToken != m_account->m_clientToken)
-    {
-        changeState(STATE_FAILED_HARD, tr("Authentication server attempted to change the client token. This isn't supported."));
-        return;
-    }
-
-    // Now, we set the access token.
-    qDebug() << "Getting new access token.";
-    QString accessToken = responseData.value("accessToken").toString("");
-    if (accessToken.isEmpty())
-    {
-        // Fail if the server didn't give us an access token.
-        changeState(STATE_FAILED_HARD, tr("Authentication server didn't send an access token."));
-        return;
-    }
-
-    // we validate that the server responded right. (our current profile = returned current
-    // profile)
-    QJsonObject currentProfile = responseData.value("selectedProfile").toObject();
-    QString currentProfileId = currentProfile.value("id").toString("");
-    if (m_account->currentProfile()->id != currentProfileId)
-    {
-        changeState(STATE_FAILED_HARD, tr("Authentication server didn't specify the same prefile as expected."));
-        return;
-    }
-
-    // this is what the vanilla launcher passes to the userProperties launch param
-    if (responseData.contains("user"))
-    {
-        User u;
-        auto obj = responseData.value("user").toObject();
-        u.id = obj.value("id").toString();
-        auto propArray = obj.value("properties").toArray();
-        for (auto prop : propArray)
-        {
-            auto propTuple = prop.toObject();
-            auto name = propTuple.value("name").toString();
-            auto value = propTuple.value("value").toString();
-            u.properties.insert(name, value);
-        }
-        m_account->m_user = u;
-    }
-
-    // We've made it through the minefield of possible errors. Return true to indicate that
-    // we've succeeded.
-    qDebug() << "Finished reading refresh response.";
-    // Reset the access token.
-    m_account->m_accessToken = accessToken;
-    changeState(STATE_SUCCEEDED);
-}
-
-QString RefreshTask::getEndpoint() const
-{
-    return "refresh";
-}
-
-QString RefreshTask::getStateMessage() const
-{
-    switch (m_state)
-    {
-    case STATE_SENDING_REQUEST:
-        return tr("Refreshing login token...");
-    case STATE_PROCESSING_RESPONSE:
-        return tr("Refreshing login token: Processing response...");
-    default:
-        return YggdrasilTask::getStateMessage();
-    }
-}
diff --git a/launcher/minecraft/auth/flows/RefreshTask.h b/launcher/minecraft/auth/flows/RefreshTask.h
deleted file mode 100644
index f0840dda..00000000
--- a/launcher/minecraft/auth/flows/RefreshTask.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include "../YggdrasilTask.h"
-
-#include <QObject>
-#include <QString>
-#include <QJsonObject>
-
-/**
- * The authenticate task takes a MojangAccount with a possibly timed-out access token
- * and attempts to authenticate with Mojang's servers.
- * If successful, it will set the new access token. The token is considered validated.
- */
-class RefreshTask : public YggdrasilTask
-{
-    Q_OBJECT
-public:
-    RefreshTask(MojangAccount * account);
-
-protected:
-    virtual QJsonObject getRequestContent() const override;
-
-    virtual QString getEndpoint() const override;
-
-    virtual void processResponse(QJsonObject responseData) override;
-
-    virtual QString getStateMessage() const override;
-};
-
diff --git a/launcher/minecraft/auth/flows/ValidateTask.cpp b/launcher/minecraft/auth/flows/ValidateTask.cpp
deleted file mode 100644
index 6b3f0a65..00000000
--- a/launcher/minecraft/auth/flows/ValidateTask.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "ValidateTask.h"
-#include "../MojangAccount.h"
-
-#include <QJsonDocument>
-#include <QJsonObject>
-#include <QJsonArray>
-#include <QVariant>
-
-#include <QDebug>
-
-ValidateTask::ValidateTask(MojangAccount * account, QObject *parent)
-    : YggdrasilTask(account, parent)
-{
-}
-
-QJsonObject ValidateTask::getRequestContent() const
-{
-    QJsonObject req;
-    req.insert("accessToken", m_account->m_accessToken);
-    return req;
-}
-
-void ValidateTask::processResponse(QJsonObject responseData)
-{
-    // Assume that if processError wasn't called, then the request was successful.
-    changeState(YggdrasilTask::STATE_SUCCEEDED);
-}
-
-QString ValidateTask::getEndpoint() const
-{
-    return "validate";
-}
-
-QString ValidateTask::getStateMessage() const
-{
-    switch (m_state)
-    {
-    case YggdrasilTask::STATE_SENDING_REQUEST:
-        return tr("Validating access token: Sending request...");
-    case YggdrasilTask::STATE_PROCESSING_RESPONSE:
-        return tr("Validating access token: Processing response...");
-    default:
-        return YggdrasilTask::getStateMessage();
-    }
-}
diff --git a/launcher/minecraft/auth/flows/ValidateTask.h b/launcher/minecraft/auth/flows/ValidateTask.h
deleted file mode 100644
index 986c2e9f..00000000
--- a/launcher/minecraft/auth/flows/ValidateTask.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/* Copyright 2013-2021 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/*
- * :FIXME: DEAD CODE, DEAD CODE, DEAD CODE! :FIXME:
- */
-
-#pragma once
-
-#include "../YggdrasilTask.h"
-
-#include <QObject>
-#include <QString>
-#include <QJsonObject>
-
-/**
- * The validate task takes a MojangAccount and checks to make sure its access token is valid.
- */
-class ValidateTask : public YggdrasilTask
-{
-    Q_OBJECT
-public:
-    ValidateTask(MojangAccount *account, QObject *parent = 0);
-
-protected:
-    virtual QJsonObject getRequestContent() const override;
-
-    virtual QString getEndpoint() const override;
-
-    virtual void processResponse(QJsonObject responseData) override;
-
-    virtual QString getStateMessage() const override;
-
-private:
-};
diff --git a/launcher/minecraft/auth/YggdrasilTask.cpp b/launcher/minecraft/auth/flows/Yggdrasil.cpp
index 0857b46b..7cea059c 100644
--- a/launcher/minecraft/auth/YggdrasilTask.cpp
+++ b/launcher/minecraft/auth/flows/Yggdrasil.cpp
@@ -13,8 +13,8 @@
  * limitations under the License.
  */
 
-#include "YggdrasilTask.h"
-#include "MojangAccount.h"
+#include "Yggdrasil.h"
+#include "../AccountData.h"
 
 #include <QObject>
 #include <QString>
@@ -29,68 +29,147 @@
 
 #include <QDebug>
 
-YggdrasilTask::YggdrasilTask(MojangAccount *account, QObject *parent)
-    : Task(parent), m_account(account)
+Yggdrasil::Yggdrasil(AccountData *data, QObject *parent)
+    : AccountTask(data, parent)
 {
     changeState(STATE_CREATED);
 }
 
-void YggdrasilTask::executeTask()
-{
-    changeState(STATE_SENDING_REQUEST);
-
-    // Get the content of the request we're going to send to the server.
-    QJsonDocument doc(getRequestContent());
+void Yggdrasil::sendRequest(QUrl endpoint, QByteArray content) {
+    changeState(STATE_WORKING);
 
-    QUrl reqUrl(BuildConfig.AUTH_BASE + getEndpoint());
-    QNetworkRequest netRequest(reqUrl);
+    QNetworkRequest netRequest(endpoint);
     netRequest.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
-
-    QByteArray requestData = doc.toJson();
-    m_netReply = ENV.qnam().post(netRequest, requestData);
-    connect(m_netReply, &QNetworkReply::finished, this, &YggdrasilTask::processReply);
-    connect(m_netReply, &QNetworkReply::uploadProgress, this, &YggdrasilTask::refreshTimers);
-    connect(m_netReply, &QNetworkReply::downloadProgress, this, &YggdrasilTask::refreshTimers);
-    connect(m_netReply, &QNetworkReply::sslErrors, this, &YggdrasilTask::sslErrors);
+    m_netReply = ENV.qnam().post(netRequest, content);
+    connect(m_netReply, &QNetworkReply::finished, this, &Yggdrasil::processReply);
+    connect(m_netReply, &QNetworkReply::uploadProgress, this, &Yggdrasil::refreshTimers);
+    connect(m_netReply, &QNetworkReply::downloadProgress, this, &Yggdrasil::refreshTimers);
+    connect(m_netReply, &QNetworkReply::sslErrors, this, &Yggdrasil::sslErrors);
     timeout_keeper.setSingleShot(true);
     timeout_keeper.start(timeout_max);
     counter.setSingleShot(false);
     counter.start(time_step);
     progress(0, timeout_max);
-    connect(&timeout_keeper, &QTimer::timeout, this, &YggdrasilTask::abortByTimeout);
-    connect(&counter, &QTimer::timeout, this, &YggdrasilTask::heartbeat);
+    connect(&timeout_keeper, &QTimer::timeout, this, &Yggdrasil::abortByTimeout);
+    connect(&counter, &QTimer::timeout, this, &Yggdrasil::heartbeat);
+}
+
+void Yggdrasil::executeTask() {
+}
+
+void Yggdrasil::refresh() {
+    start();
+    /*
+     * {
+     *  "clientToken": "client identifier"
+     *  "accessToken": "current access token to be refreshed"
+     *  "selectedProfile":                      // specifying this causes errors
+     *  {
+     *   "id": "profile ID"
+     *   "name": "profile name"
+     *  }
+     *  "requestUser": true/false               // request the user structure
+     * }
+     */
+    QJsonObject req;
+    req.insert("clientToken", m_data->clientToken());
+    req.insert("accessToken", m_data->accessToken());
+    /*
+    {
+        auto currentProfile = m_account->currentProfile();
+        QJsonObject profile;
+        profile.insert("id", currentProfile->id());
+        profile.insert("name", currentProfile->name());
+        req.insert("selectedProfile", profile);
+    }
+    */
+    req.insert("requestUser", false);
+    QJsonDocument doc(req);
+
+    QUrl reqUrl(BuildConfig.AUTH_BASE + "refresh");
+    QByteArray requestData = doc.toJson();
+
+    sendRequest(reqUrl, requestData);
+}
+
+void Yggdrasil::login(QString password) {
+    start();
+    /*
+     * {
+     *   "agent": {                              // optional
+     *   "name": "Minecraft",                    // So far this is the only encountered value
+     *   "version": 1                            // This number might be increased
+     *                                           // by the vanilla client in the future
+     *   },
+     *   "username": "mojang account name",      // Can be an email address or player name for
+     *                                           // unmigrated accounts
+     *   "password": "mojang account password",
+     *   "clientToken": "client identifier",     // optional
+     *   "requestUser": true/false               // request the user structure
+     * }
+     */
+    QJsonObject req;
+
+    {
+        QJsonObject agent;
+        // C++ makes string literals void* for some stupid reason, so we have to tell it
+        // QString... Thanks Obama.
+        agent.insert("name", QString("Minecraft"));
+        agent.insert("version", 1);
+        req.insert("agent", agent);
+    }
+
+    req.insert("username", m_data->userName());
+    req.insert("password", password);
+    req.insert("requestUser", false);
+
+    // If we already have a client token, give it to the server.
+    // Otherwise, let the server give us one.
+
+    m_data->generateClientTokenIfMissing();
+    req.insert("clientToken", m_data->clientToken());
+
+    QJsonDocument doc(req);
+
+    QUrl reqUrl(BuildConfig.AUTH_BASE + "authenticate");
+    QNetworkRequest netRequest(reqUrl);
+    QByteArray requestData = doc.toJson();
+
+    sendRequest(reqUrl, requestData);
 }
 
-void YggdrasilTask::refreshTimers(qint64, qint64)
+
+
+void Yggdrasil::refreshTimers(qint64, qint64)
 {
     timeout_keeper.stop();
     timeout_keeper.start(timeout_max);
     progress(count = 0, timeout_max);
 }
-void YggdrasilTask::heartbeat()
+void Yggdrasil::heartbeat()
 {
     count += time_step;
     progress(count, timeout_max);
 }
 
-bool YggdrasilTask::abort()
+bool Yggdrasil::abort()
 {
     progress(timeout_max, timeout_max);
     // TODO: actually use this in a meaningful way
-    m_aborted = YggdrasilTask::BY_USER;
+    m_aborted = Yggdrasil::BY_USER;
     m_netReply->abort();
     return true;
 }
 
-void YggdrasilTask::abortByTimeout()
+void Yggdrasil::abortByTimeout()
 {
     progress(timeout_max, timeout_max);
     // TODO: actually use this in a meaningful way
-    m_aborted = YggdrasilTask::BY_TIMEOUT;
+    m_aborted = Yggdrasil::BY_TIMEOUT;
     m_netReply->abort();
 }
 
-void YggdrasilTask::sslErrors(QList<QSslError> errors)
+void Yggdrasil::sslErrors(QList<QSslError> errors)
 {
     int i = 1;
     for (auto error : errors)
@@ -102,9 +181,52 @@ void YggdrasilTask::sslErrors(QList<QSslError> errors)
     }
 }
 
-void YggdrasilTask::processReply()
+void Yggdrasil::processResponse(QJsonObject responseData)
+{
+    // Read the response data. We need to get the client token, access token, and the selected
+    // profile.
+    qDebug() << "Processing authentication response.";
+
+    // qDebug() << responseData;
+    // If we already have a client token, make sure the one the server gave us matches our
+    // existing one.
+    QString clientToken = responseData.value("clientToken").toString("");
+    if (clientToken.isEmpty())
+    {
+        // Fail if the server gave us an empty client token
+        changeState(STATE_FAILED_HARD, tr("Authentication server didn't send a client token."));
+        return;
+    }
+    if(m_data->clientToken().isEmpty()) {
+        m_data->setClientToken(clientToken);
+    }
+    else if(clientToken != m_data->clientToken()) {
+        changeState(STATE_FAILED_HARD, tr("Authentication server attempted to change the client token. This isn't supported."));
+        return;
+    }
+
+    // Now, we set the access token.
+    qDebug() << "Getting access token.";
+    QString accessToken = responseData.value("accessToken").toString("");
+    if (accessToken.isEmpty())
+    {
+        // Fail if the server didn't give us an access token.
+        changeState(STATE_FAILED_HARD, tr("Authentication server didn't send an access token."));
+        return;
+    }
+    // Set the access token.
+    m_data->yggdrasilToken.token = accessToken;
+    m_data->yggdrasilToken.validity = Katabasis::Validity::Certain;
+
+    // We've made it through the minefield of possible errors. Return true to indicate that
+    // we've succeeded.
+    qDebug() << "Finished reading authentication response.";
+    changeState(STATE_SUCCEEDED);
+}
+
+void Yggdrasil::processReply()
 {
-    changeState(STATE_PROCESSING_RESPONSE);
+    changeState(STATE_WORKING);
 
     switch (m_netReply->error())
     {
@@ -195,7 +317,7 @@ void YggdrasilTask::processReply()
     }
 }
 
-void YggdrasilTask::processError(QJsonObject responseData)
+void Yggdrasil::processError(QJsonObject responseData)
 {
     QJsonValue errorVal = responseData.value("error");
     QJsonValue errorMessageValue = responseData.value("errorMessage");
@@ -213,43 +335,3 @@ void YggdrasilTask::processError(QJsonObject responseData)
         changeState(STATE_FAILED_HARD, tr("An unknown Yggdrasil error occurred."));
     }
 }
-
-QString YggdrasilTask::getStateMessage() const
-{
-    switch (m_state)
-    {
-    case STATE_CREATED:
-        return "Waiting...";
-    case STATE_SENDING_REQUEST:
-        return tr("Sending request to auth servers...");
-    case STATE_PROCESSING_RESPONSE:
-        return tr("Processing response from servers...");
-    case STATE_SUCCEEDED:
-        return tr("Authentication task succeeded.");
-    case STATE_FAILED_SOFT:
-        return tr("Failed to contact the authentication server.");
-    case STATE_FAILED_HARD:
-        return tr("Failed to authenticate.");
-    default:
-        return tr("...");
-    }
-}
-
-void YggdrasilTask::changeState(YggdrasilTask::State newState, QString reason)
-{
-    m_state = newState;
-    setStatus(getStateMessage());
-    if (newState == STATE_SUCCEEDED)
-    {
-        emitSucceeded();
-    }
-    else if (newState == STATE_FAILED_HARD || newState == STATE_FAILED_SOFT)
-    {
-        emitFailed(reason);
-    }
-}
-
-YggdrasilTask::State YggdrasilTask::state()
-{
-    return m_state;
-}
diff --git a/launcher/minecraft/auth/flows/Yggdrasil.h b/launcher/minecraft/auth/flows/Yggdrasil.h
new file mode 100644
index 00000000..e709cb9f
--- /dev/null
+++ b/launcher/minecraft/auth/flows/Yggdrasil.h
@@ -0,0 +1,82 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "../AccountTask.h"
+
+#include <QString>
+#include <QJsonObject>
+#include <QTimer>
+#include <qsslerror.h>
+
+#include "../MinecraftAccount.h"
+
+class QNetworkReply;
+
+/**
+ * A Yggdrasil task is a task that performs an operation on a given mojang account.
+ */
+class Yggdrasil : public AccountTask
+{
+    Q_OBJECT
+public:
+    explicit Yggdrasil(AccountData * data, QObject *parent = 0);
+    virtual ~Yggdrasil() {};
+
+    void refresh();
+    void login(QString password);
+protected:
+    void executeTask() override;
+
+    /**
+     * Processes the response received from the server.
+     * If an error occurred, this should emit a failed signal.
+     * If Yggdrasil gave an error response, it should call setError() first, and then return false.
+     * Otherwise, it should return true.
+     * Note: If the response from the server was blank, and the HTTP code was 200, this function is called with
+     * an empty QJsonObject.
+     */
+    void processResponse(QJsonObject responseData);
+
+    /**
+     * Processes an error response received from the server.
+     * The default implementation will read data from Yggdrasil's standard error response format and set it as this task's Error.
+     * \returns a QString error message that will be passed to emitFailed.
+     */
+    virtual void processError(QJsonObject responseData);
+
+protected slots:
+    void processReply();
+    void refreshTimers(qint64, qint64);
+    void heartbeat();
+    void sslErrors(QList<QSslError>);
+    void abortByTimeout();
+
+public slots:
+    virtual bool abort() override;
+
+private:
+    void sendRequest(QUrl endpoint, QByteArray content);
+
+protected:
+    QNetworkReply *m_netReply = nullptr;
+    QTimer timeout_keeper;
+    QTimer counter;
+    int count = 0; // num msec since time reset
+
+    const int timeout_max = 30000;
+    const int time_step = 50;
+};
diff --git a/launcher/minecraft/launch/ClaimAccount.h b/launcher/minecraft/launch/ClaimAccount.h
index c5bd75f3..cb4de23f 100644
--- a/launcher/minecraft/launch/ClaimAccount.h
+++ b/launcher/minecraft/launch/ClaimAccount.h
@@ -16,7 +16,7 @@
 #pragma once
 
 #include <launch/LaunchStep.h>
-#include <minecraft/auth/MojangAccount.h>
+#include <minecraft/auth/MinecraftAccount.h>
 
 class ClaimAccount: public LaunchStep
 {
@@ -33,5 +33,5 @@ public:
     }
 private:
     std::unique_ptr<UseLock> lock;
-    MojangAccountPtr m_account;
+    MinecraftAccountPtr m_account;
 };
diff --git a/launcher/pages/global/AccountListPage.cpp b/launcher/pages/global/AccountListPage.cpp
index ff3736ed..a3cd86a4 100644
--- a/launcher/pages/global/AccountListPage.cpp
+++ b/launcher/pages/global/AccountListPage.cpp
@@ -29,12 +29,13 @@
 #include "dialogs/CustomMessageBox.h"
 #include "dialogs/SkinUploadDialog.h"
 #include "tasks/Task.h"
-#include "minecraft/auth/YggdrasilTask.h"
+#include "minecraft/auth/AccountTask.h"
 #include "minecraft/services/SkinDelete.h"
 
 #include "MultiMC.h"
 
 #include "BuildConfig.h"
+#include <dialogs/MSALoginDialog.h>
 
 AccountListPage::AccountListPage(QWidget *parent)
     : QMainWindow(parent), ui(new Ui::AccountListPage)
@@ -50,11 +51,12 @@ AccountListPage::AccountListPage(QWidget *parent)
     m_accounts = MMC->accounts();
 
     ui->listView->setModel(m_accounts.get());
-    ui->listView->header()->setSectionResizeMode(QHeaderView::ResizeToContents);
+    ui->listView->header()->setSectionResizeMode(0, QHeaderView::Stretch);
+    ui->listView->header()->setSectionResizeMode(1, QHeaderView::Stretch);
+    ui->listView->header()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
     ui->listView->setSelectionMode(QAbstractItemView::SingleSelection);
 
     // Expand the account column
-    ui->listView->header()->setSectionResizeMode(1, QHeaderView::Stretch);
 
     QItemSelectionModel *selectionModel = ui->listView->selectionModel();
 
@@ -63,8 +65,8 @@ AccountListPage::AccountListPage(QWidget *parent)
     });
     connect(ui->listView, &VersionListView::customContextMenuRequested, this, &AccountListPage::ShowContextMenu);
 
-    connect(m_accounts.get(), SIGNAL(listChanged()), SLOT(listChanged()));
-    connect(m_accounts.get(), SIGNAL(activeAccountChanged()), SLOT(listChanged()));
+    connect(m_accounts.get(), &AccountList::listChanged, this, &AccountListPage::listChanged);
+    connect(m_accounts.get(), &AccountList::activeAccountChanged, this, &AccountListPage::listChanged);
 
     updateButtonStates();
 }
@@ -103,9 +105,36 @@ void AccountListPage::listChanged()
     updateButtonStates();
 }
 
-void AccountListPage::on_actionAdd_triggered()
+void AccountListPage::on_actionAddMojang_triggered()
 {
-    addAccount(tr("Please enter your Minecraft account email and password to add your account."));
+    MinecraftAccountPtr account = LoginDialog::newAccount(
+        this,
+        tr("Please enter your Mojang account email and password to add your account.")
+    );
+
+    if (account != nullptr)
+    {
+        m_accounts->addAccount(account);
+        if (m_accounts->count() == 1) {
+            m_accounts->setActiveAccount(account->profileId());
+        }
+    }
+}
+
+void AccountListPage::on_actionAddMicrosoft_triggered()
+{
+    MinecraftAccountPtr account = MSALoginDialog::newAccount(
+        this,
+        tr("Please enter your Mojang account email and password to add your account.")
+    );
+
+    if (account != nullptr)
+    {
+        m_accounts->addAccount(account);
+        if (m_accounts->count() == 1) {
+            m_accounts->setActiveAccount(account->profileId());
+        }
+    }
 }
 
 void AccountListPage::on_actionRemove_triggered()
@@ -124,9 +153,8 @@ void AccountListPage::on_actionSetDefault_triggered()
     if (selection.size() > 0)
     {
         QModelIndex selected = selection.first();
-        MojangAccountPtr account =
-            selected.data(MojangAccountList::PointerRole).value<MojangAccountPtr>();
-        m_accounts->setActiveAccount(account->username());
+        MinecraftAccountPtr account = selected.data(AccountList::PointerRole).value<MinecraftAccountPtr>();
+        m_accounts->setActiveAccount(account->profileId());
     }
 }
 
@@ -156,39 +184,13 @@ void AccountListPage::updateButtonStates()
 
 }
 
-void AccountListPage::addAccount(const QString &errMsg)
-{
-    // TODO: The login dialog isn't quite done yet
-    MojangAccountPtr account = LoginDialog::newAccount(this, errMsg);
-
-    if (account != nullptr)
-    {
-        m_accounts->addAccount(account);
-        if (m_accounts->count() == 1)
-            m_accounts->setActiveAccount(account->username());
-
-        // Grab associated player skins
-        auto job = new NetJob("Player skins: " + account->username());
-
-        for (AccountProfile profile : account->profiles())
-        {
-            auto meta = Env::getInstance().metacache()->resolveEntry("skins", profile.id + ".png");
-            auto action = Net::Download::makeCached(QUrl(BuildConfig.SKINS_BASE + profile.id + ".png"), meta);
-            job->addNetAction(action);
-            meta->setStale(true);
-        }
-
-        job->start();
-    }
-}
-
 void AccountListPage::on_actionUploadSkin_triggered()
 {
     QModelIndexList selection = ui->listView->selectionModel()->selectedIndexes();
     if (selection.size() > 0)
     {
         QModelIndex selected = selection.first();
-        MojangAccountPtr account = selected.data(MojangAccountList::PointerRole).value<MojangAccountPtr>();
+        MinecraftAccountPtr account = selected.data(AccountList::PointerRole).value<MinecraftAccountPtr>();
         SkinUploadDialog dialog(account, this);
         dialog.exec();
     }
@@ -202,8 +204,8 @@ void AccountListPage::on_actionDeleteSkin_triggered()
 
     QModelIndex selected = selection.first();
     AuthSessionPtr session = std::make_shared<AuthSession>();
-    MojangAccountPtr account = selected.data(MojangAccountList::PointerRole).value<MojangAccountPtr>();
-    auto login = account->login(session);
+    MinecraftAccountPtr account = selected.data(AccountList::PointerRole).value<MinecraftAccountPtr>();
+    auto login = account->refresh(session);
     ProgressDialog prog(this);
     if (prog.execWithTask((Task*)login.get()) != QDialog::Accepted) {
         CustomMessageBox::selectable(this, tr("Skin Delete"), tr("Failed to login!"), QMessageBox::Warning)->exec();
diff --git a/launcher/pages/global/AccountListPage.h b/launcher/pages/global/AccountListPage.h
index fba1833f..24bb96da 100644
--- a/launcher/pages/global/AccountListPage.h
+++ b/launcher/pages/global/AccountListPage.h
@@ -20,7 +20,7 @@
 
 #include "pages/BasePage.h"
 
-#include "minecraft/auth/MojangAccountList.h"
+#include "minecraft/auth/AccountList.h"
 #include "MultiMC.h"
 
 namespace Ui
@@ -60,7 +60,8 @@ public:
     }
 
 public slots:
-    void on_actionAdd_triggered();
+    void on_actionAddMojang_triggered();
+    void on_actionAddMicrosoft_triggered();
     void on_actionRemove_triggered();
     void on_actionSetDefault_triggered();
     void on_actionNoDefault_triggered();
@@ -74,11 +75,10 @@ public slots:
 
 protected slots:
     void ShowContextMenu(const QPoint &pos);
-    void addAccount(const QString& errMsg="");
 
 private:
     void changeEvent(QEvent * event) override;
     QMenu * createPopupMenu() override;
-    std::shared_ptr<MojangAccountList> m_accounts;
+    std::shared_ptr<AccountList> m_accounts;
     Ui::AccountListPage *ui;
 };
diff --git a/launcher/pages/global/AccountListPage.ui b/launcher/pages/global/AccountListPage.ui
index 71647db3..887c3d48 100644
--- a/launcher/pages/global/AccountListPage.ui
+++ b/launcher/pages/global/AccountListPage.ui
@@ -25,7 +25,23 @@
      <number>0</number>
     </property>
     <item>
-     <widget class="VersionListView" name="listView"/>
+     <widget class="VersionListView" name="listView">
+      <property name="alternatingRowColors">
+       <bool>true</bool>
+      </property>
+      <property name="rootIsDecorated">
+       <bool>false</bool>
+      </property>
+      <property name="itemsExpandable">
+       <bool>false</bool>
+      </property>
+      <property name="allColumnsShowFocus">
+       <bool>true</bool>
+      </property>
+      <attribute name="headerStretchLastSection">
+       <bool>false</bool>
+      </attribute>
+     </widget>
     </item>
    </layout>
   </widget>
@@ -36,7 +52,8 @@
    <attribute name="toolBarBreak">
     <bool>false</bool>
    </attribute>
-   <addaction name="actionAdd"/>
+   <addaction name="actionAddMicrosoft"/>
+   <addaction name="actionAddMojang"/>
    <addaction name="actionRemove"/>
    <addaction name="actionSetDefault"/>
    <addaction name="actionNoDefault"/>
@@ -44,9 +61,9 @@
    <addaction name="actionUploadSkin"/>
    <addaction name="actionDeleteSkin"/>
   </widget>
-  <action name="actionAdd">
+  <action name="actionAddMojang">
    <property name="text">
-    <string>Add</string>
+    <string>Add Mojang</string>
    </property>
   </action>
   <action name="actionRemove">
@@ -80,6 +97,11 @@
     <string>Delete the currently active skin and go back to the default one</string>
    </property>
   </action>
+  <action name="actionAddMicrosoft">
+   <property name="text">
+    <string>Add Microsoft</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>
diff --git a/launcher/pages/instance/VersionPage.cpp b/launcher/pages/instance/VersionPage.cpp
index a98bfb7d..20cb2c9f 100644
--- a/launcher/pages/instance/VersionPage.cpp
+++ b/launcher/pages/instance/VersionPage.cpp
@@ -38,7 +38,7 @@
 #include <QUrl>
 
 #include "minecraft/PackProfile.h"
-#include "minecraft/auth/MojangAccountList.h"
+#include "minecraft/auth/AccountList.h"
 #include "minecraft/mod/Mod.h"
 #include "icons/IconList.h"
 #include "Exception.h"