diff --git a/Minecraft.Client/CMakeLists.txt b/Minecraft.Client/CMakeLists.txt
index 3b029610..e46257cf 100644
--- a/Minecraft.Client/CMakeLists.txt
+++ b/Minecraft.Client/CMakeLists.txt
@@ -51,9 +51,11 @@ set_target_properties(Minecraft.Client PROPERTIES
 
 target_link_libraries(Minecraft.Client PRIVATE
   Minecraft.World
+  crypt32
   d3d11
   d3dcompiler
   XInput9_1_0
+  winhttp
   wsock32
   legacy_stdio_definitions
   $<$<CONFIG:Debug>: # Debug 4J libraries
diff --git a/Minecraft.Client/Common/Media/LceLive1080.swf b/Minecraft.Client/Common/Media/LceLive1080.swf
new file mode 100644
index 00000000..63f5e367
Binary files /dev/null and b/Minecraft.Client/Common/Media/LceLive1080.swf differ
diff --git a/Minecraft.Client/Common/Media/LceLive480.swf b/Minecraft.Client/Common/Media/LceLive480.swf
new file mode 100644
index 00000000..f59582c4
Binary files /dev/null and b/Minecraft.Client/Common/Media/LceLive480.swf differ
diff --git a/Minecraft.Client/Common/Media/LceLive720.swf b/Minecraft.Client/Common/Media/LceLive720.swf
new file mode 100644
index 00000000..d6afdee6
Binary files /dev/null and b/Minecraft.Client/Common/Media/LceLive720.swf differ
diff --git a/Minecraft.Client/Common/Media/LceLiveVita.swf b/Minecraft.Client/Common/Media/LceLiveVita.swf
new file mode 100644
index 00000000..459be153
Binary files /dev/null and b/Minecraft.Client/Common/Media/LceLiveVita.swf differ
diff --git a/Minecraft.Client/Common/Media/MainMenu1080.swf b/Minecraft.Client/Common/Media/MainMenu1080.swf
index a3c55273..b7ac6005 100644
Binary files a/Minecraft.Client/Common/Media/MainMenu1080.swf and b/Minecraft.Client/Common/Media/MainMenu1080.swf differ
diff --git a/Minecraft.Client/Common/Media/MainMenu480.swf b/Minecraft.Client/Common/Media/MainMenu480.swf
index adc8e52a..d1d9146a 100644
Binary files a/Minecraft.Client/Common/Media/MainMenu480.swf and b/Minecraft.Client/Common/Media/MainMenu480.swf differ
diff --git a/Minecraft.Client/Common/Media/MainMenu720.swf b/Minecraft.Client/Common/Media/MainMenu720.swf
index 3823791e..da6374be 100644
Binary files a/Minecraft.Client/Common/Media/MainMenu720.swf and b/Minecraft.Client/Common/Media/MainMenu720.swf differ
diff --git a/Minecraft.Client/Common/Media/MainMenuVita.swf b/Minecraft.Client/Common/Media/MainMenuVita.swf
index c9477bce..e8d1a68e 100644
Binary files a/Minecraft.Client/Common/Media/MainMenuVita.swf and b/Minecraft.Client/Common/Media/MainMenuVita.swf differ
diff --git a/Minecraft.Client/Common/Media/MediaWindows64.arc b/Minecraft.Client/Common/Media/MediaWindows64.arc
index b810e4d8..cf09046c 100644
Binary files a/Minecraft.Client/Common/Media/MediaWindows64.arc and b/Minecraft.Client/Common/Media/MediaWindows64.arc differ
diff --git a/Minecraft.Client/Common/UI/UI.h b/Minecraft.Client/Common/UI/UI.h
index a7c416f8..771f7531 100644
--- a/Minecraft.Client/Common/UI/UI.h
+++ b/Minecraft.Client/Common/UI/UI.h
@@ -65,6 +65,7 @@
 
 #include "UIScene_TrialExitUpsell.h"
 #include "UIScene_Intro.h"
+#include "UIScene_LceLive.h"
 #include "UIScene_SaveMessage.h"
 #include "UIScene_MainMenu.h"
 #include "UIScene_LoadMenu.h"
@@ -125,4 +126,4 @@
 #include "UIScene_EULA.h"
 #include "UIScene_NewUpdateMessage.h"
 
-extern ConsoleUIController ui;
\ No newline at end of file
+extern ConsoleUIController ui;
diff --git a/Minecraft.Client/Common/UI/UIEnums.h b/Minecraft.Client/Common/UI/UIEnums.h
index 45aff87d..91d0046a 100644
--- a/Minecraft.Client/Common/UI/UIEnums.h
+++ b/Minecraft.Client/Common/UI/UIEnums.h
@@ -121,6 +121,7 @@ enum EUIScene
 	eUIComponent_Tooltips,
 	eUIComponent_PressStartToPlay,
 	eUIComponent_MenuBackground,
+	eUIScene_LceLive,
 	eUIScene_Keyboard,
 	eUIScene_QuadrantSignin,
 	eUIScene_MessageBox,
diff --git a/Minecraft.Client/Common/UI/UILayer.cpp b/Minecraft.Client/Common/UI/UILayer.cpp
index e1c388f5..15552e33 100644
--- a/Minecraft.Client/Common/UI/UILayer.cpp
+++ b/Minecraft.Client/Common/UI/UILayer.cpp
@@ -364,6 +364,9 @@ bool UILayer::NavigateToScene(int iPad, EUIScene scene, void *initData)
 	case eUIScene_SaveMessage:
 		newScene = new UIScene_SaveMessage(iPad, initData, this);
 		break;
+	case eUIScene_LceLive:
+		newScene = new UIScene_LceLive(iPad, initData, this);
+		break;
 	case eUIScene_MainMenu:
 		newScene = new UIScene_MainMenu(iPad, initData, this);
 		break;
@@ -906,4 +909,4 @@ UIScene *UILayer::FindScene(EUIScene sceneType)
 	}
 
 	return nullptr;
-}
\ No newline at end of file
+}
diff --git a/Minecraft.Client/Common/UI/UIScene_LceLive.cpp b/Minecraft.Client/Common/UI/UIScene_LceLive.cpp
new file mode 100644
index 00000000..32f8aeeb
--- /dev/null
+++ b/Minecraft.Client/Common/UI/UIScene_LceLive.cpp
@@ -0,0 +1,198 @@
+#include "stdafx.h"
+#include "UI.h"
+#include "UIScene_LceLive.h"
+#include "../../../Minecraft.World/StringHelpers.h"
+
+#if defined(_WINDOWS64) && !defined(MINECRAFT_SERVER_BUILD)
+#include "../../Windows64/Windows64_LceLive.h"
+#endif
+
+UIScene_LceLive::UIScene_LceLive(int iPad, void *initData, UILayer *parentLayer) : UIScene(iPad, parentLayer)
+{
+	initialiseMovie();
+
+	parentLayer->addComponent(iPad, eUIComponent_Panorama);
+	parentLayer->addComponent(iPad, eUIComponent_Logo);
+
+	m_buttonEnabled = true;
+	m_descriptionApplied = false;
+	m_buttonPrimaryAction.init(L"START LINK", eControl_PrimaryAction);
+	m_labelTitle.init(L"LCELIVE");
+	m_labelDescription.init(L"");
+
+	IggyDataValue result;
+	IggyDataValue value[2];
+	value[0].type = IGGY_DATATYPE_number;
+	value[0].number = 1;
+	value[1].type = IGGY_DATATYPE_number;
+	value[1].number = 0;
+	IggyPlayerCallMethodRS(getMovie(), &result, IggyPlayerRootPath(getMovie()), m_funcInit, 2, value);
+	IggyPlayerCallMethodRS(getMovie(), &result, IggyPlayerRootPath(getMovie()), m_funcAutoResize, 0, nullptr);
+}
+
+UIScene_LceLive::~UIScene_LceLive()
+{
+	m_parentLayer->removeComponent(eUIComponent_Panorama);
+	m_parentLayer->removeComponent(eUIComponent_Logo);
+}
+
+wstring UIScene_LceLive::getMoviePath()
+{
+	return L"LceLive";
+}
+
+void UIScene_LceLive::updateTooltips()
+{
+	if (m_buttonEnabled)
+		ui.SetTooltips(DEFAULT_XUI_MENU_USER, IDS_TOOLTIPS_SELECT, IDS_TOOLTIPS_BACK);
+	else
+		ui.SetTooltips(DEFAULT_XUI_MENU_USER, -1, IDS_TOOLTIPS_BACK);
+}
+
+void UIScene_LceLive::updateComponents()
+{
+	m_parentLayer->showComponent(m_iPad, eUIComponent_Panorama, true);
+	m_parentLayer->showComponent(m_iPad, eUIComponent_Logo, true);
+}
+
+void UIScene_LceLive::tick()
+{
+	UIScene::tick();
+	RefreshUi(false);
+}
+
+void UIScene_LceLive::handleReload()
+{
+	m_descriptionApplied = false;
+	IggyDataValue result;
+	IggyDataValue value[2];
+	value[0].type = IGGY_DATATYPE_number;
+	value[0].number = 1;
+	value[1].type = IGGY_DATATYPE_number;
+	value[1].number = 0;
+	IggyPlayerCallMethodRS(getMovie(), &result, IggyPlayerRootPath(getMovie()), m_funcInit, 2, value);
+	IggyPlayerCallMethodRS(getMovie(), &result, IggyPlayerRootPath(getMovie()), m_funcAutoResize, 0, nullptr);
+	RefreshUi(true);
+}
+
+void UIScene_LceLive::handleInput(int iPad, int key, bool repeat, bool pressed, bool released, bool &handled)
+{
+	ui.AnimateKeyPress(m_iPad, key, repeat, pressed, released);
+
+	switch (key)
+	{
+	case ACTION_MENU_CANCEL:
+		if (pressed && !repeat)
+			navigateBack();
+		break;
+	case ACTION_MENU_OK:
+		if (pressed && !repeat && m_buttonEnabled)
+		{
+			handled = true;
+			handlePress(static_cast<F64>(eControl_PrimaryAction), 0.0);
+		}
+		break;
+#ifdef __ORBIS__
+	case ACTION_MENU_TOUCHPAD_PRESS:
+		if (pressed && !repeat && m_buttonEnabled)
+		{
+			handled = true;
+			handlePress(static_cast<F64>(eControl_PrimaryAction), 0.0);
+		}
+		break;
+#endif
+	case ACTION_MENU_DOWN:
+	case ACTION_MENU_UP:
+	case ACTION_MENU_PAGEUP:
+	case ACTION_MENU_PAGEDOWN:
+	case ACTION_MENU_OTHER_STICK_DOWN:
+	case ACTION_MENU_OTHER_STICK_UP:
+		sendInputToMovie(key, repeat, pressed, released);
+		break;
+	}
+}
+
+void UIScene_LceLive::handlePress(F64 controlId, F64 childId)
+{
+	if (static_cast<int>(controlId) != eControl_PrimaryAction || !m_buttonEnabled)
+		return;
+
+#if defined(_WINDOWS64) && !defined(MINECRAFT_SERVER_BUILD)
+	const Win64LceLive::Snapshot snapshot = Win64LceLive::GetSnapshot();
+	ui.PlayUISFX(eSFX_Press);
+
+	if (snapshot.state == Win64LceLive::EClientState::SignedIn)
+		Win64LceLive::SignOut();
+	else
+		Win64LceLive::StartDeviceLink();
+#endif
+}
+
+void UIScene_LceLive::RefreshUi(bool force)
+{
+	std::wstring buttonLabel = L"LCELIVE UNAVAILABLE";
+	std::wstring description = L"LCELIVE\r\n\r\nThis build does not provide the Windows64 LCELive client runtime.";
+	bool buttonEnabled = false;
+
+#if defined(_WINDOWS64) && !defined(MINECRAFT_SERVER_BUILD)
+	const Win64LceLive::Snapshot snapshot = Win64LceLive::GetSnapshot();
+
+	switch (snapshot.state)
+	{
+	case Win64LceLive::EClientState::SignedIn:
+		buttonLabel = L"SIGN OUT";
+		buttonEnabled = !snapshot.requestInFlight;
+		break;
+	case Win64LceLive::EClientState::StartingLink:
+	case Win64LceLive::EClientState::Polling:
+		buttonLabel = L"PLEASE WAIT";
+		buttonEnabled = false;
+		break;
+	case Win64LceLive::EClientState::LinkPending:
+		buttonLabel = L"RESTART LINK";
+		buttonEnabled = true;
+		break;
+	case Win64LceLive::EClientState::SignedOut:
+	default:
+		buttonLabel = L"START LINK";
+		buttonEnabled = true;
+		break;
+	}
+
+	description = snapshot.statusMessage;
+	if (snapshot.hasError && !snapshot.errorMessage.empty())
+	{
+		description += L"\r\nError:\r\n";
+		description += snapshot.errorMessage;
+	}
+#endif
+
+	if (force || m_lastButtonLabel != buttonLabel)
+	{
+		m_lastButtonLabel = buttonLabel;
+		m_buttonPrimaryAction.setLabel(buttonLabel, true, true);
+	}
+
+	if (force || m_buttonEnabled != buttonEnabled)
+	{
+		m_buttonEnabled = buttonEnabled;
+		m_buttonPrimaryAction.setEnable(buttonEnabled);
+	}
+
+	if (!m_descriptionApplied || m_lastDescription != description)
+	{
+		m_lastDescription = description;
+		ApplyDescription(description);
+	}
+
+	updateTooltips();
+}
+
+void UIScene_LceLive::ApplyDescription(const std::wstring &description)
+{
+	m_labelDescription.setLabel(description, true, true);
+
+	IggyDataValue result;
+	IggyPlayerCallMethodRS(getMovie(), &result, IggyPlayerRootPath(getMovie()), m_funcAutoResize, 0, nullptr);
+	m_descriptionApplied = true;
+}
diff --git a/Minecraft.Client/Common/UI/UIScene_LceLive.h b/Minecraft.Client/Common/UI/UIScene_LceLive.h
new file mode 100644
index 00000000..fa7a43b4
--- /dev/null
+++ b/Minecraft.Client/Common/UI/UIScene_LceLive.h
@@ -0,0 +1,53 @@
+#pragma once
+
+#include "UIScene.h"
+
+class UIScene_LceLive : public UIScene
+{
+private:
+	enum EControls
+	{
+		eControl_PrimaryAction,
+	};
+
+	bool m_buttonEnabled;
+	bool m_descriptionApplied;
+	std::wstring m_lastButtonLabel;
+	std::wstring m_lastDescription;
+
+	UIControl_Button m_buttonPrimaryAction;
+	UIControl_Label m_labelTitle;
+	UIControl_Label m_labelDescription;
+	IggyName m_funcInit;
+	IggyName m_funcAutoResize;
+	UI_BEGIN_MAP_ELEMENTS_AND_NAMES(UIScene)
+		UI_MAP_ELEMENT(m_buttonPrimaryAction, "Button3")
+		UI_MAP_ELEMENT(m_labelTitle, "Title")
+		UI_MAP_ELEMENT(m_labelDescription, "Content")
+		UI_MAP_NAME(m_funcInit, L"Init")
+		UI_MAP_NAME(m_funcAutoResize, L"AutoResize")
+	UI_END_MAP_ELEMENTS_AND_NAMES()
+
+public:
+	UIScene_LceLive(int iPad, void *initData, UILayer *parentLayer);
+	~UIScene_LceLive();
+
+	virtual EUIScene getSceneType() { return eUIScene_LceLive; }
+	virtual void updateTooltips();
+	virtual void updateComponents();
+	virtual void tick();
+
+protected:
+	virtual wstring getMoviePath();
+	virtual void handleReload();
+
+public:
+	virtual void handleInput(int iPad, int key, bool repeat, bool pressed, bool released, bool &handled);
+
+protected:
+	void handlePress(F64 controlId, F64 childId);
+
+private:
+	void RefreshUi(bool force);
+	void ApplyDescription(const std::wstring &description);
+};
diff --git a/Minecraft.Client/Common/UI/UIScene_MainMenu.cpp b/Minecraft.Client/Common/UI/UIScene_MainMenu.cpp
index 1eef994f..fef040a4 100644
--- a/Minecraft.Client/Common/UI/UIScene_MainMenu.cpp
+++ b/Minecraft.Client/Common/UI/UIScene_MainMenu.cpp
@@ -41,7 +41,7 @@ UIScene_MainMenu::UIScene_MainMenu(int iPad, void *initData, UILayer *parentLaye
 #endif
 
 	m_buttons[static_cast<int>(eControl_Leaderboards)].init(IDS_LEADERBOARDS,eControl_Leaderboards);
-	m_buttons[static_cast<int>(eControl_Achievements)].init( (UIString)IDS_ACHIEVEMENTS,eControl_Achievements);
+	m_buttons[static_cast<int>(eControl_Achievements)].init((UIString)IDS_ACHIEVEMENTS, eControl_Achievements);
 	m_buttons[static_cast<int>(eControl_HelpAndOptions)].init(IDS_HELP_AND_OPTIONS,eControl_HelpAndOptions);
 	if(ProfileManager.IsFullVersion())
 	{
@@ -54,6 +54,13 @@ UIScene_MainMenu::UIScene_MainMenu(int iPad, void *initData, UILayer *parentLaye
 		m_buttons[static_cast<int>(eControl_UnlockOrDLC)].init(IDS_UNLOCK_FULL_GAME,eControl_UnlockOrDLC);
 	}
 
+#if defined(_WINDOWS64) && !defined(MINECRAFT_SERVER_BUILD)
+	m_buttons[static_cast<int>(eControl_LceLive)].init(L"LCELIVE", eControl_LceLive);
+#else
+	m_buttons[static_cast<int>(eControl_LceLive)].init(L"LCELIVE", eControl_LceLive);
+	removeControl(&m_buttons[(int)eControl_LceLive], false);
+#endif
+
 #ifndef _DURANGO
 	m_buttons[static_cast<int>(eControl_Exit)].init(app.GetString(IDS_EXIT_GAME),eControl_Exit);
 #else
@@ -65,11 +72,13 @@ UIScene_MainMenu::UIScene_MainMenu(int iPad, void *initData, UILayer *parentLaye
 	removeControl( &m_buttons[(int)eControl_Exit], false );
 	// We don't have a way to display trophies/achievements, so remove the button
 	removeControl( &m_buttons[(int)eControl_Achievements], false );
+	removeControl( &m_buttons[(int)eControl_LceLive], false );
 	m_bLaunchFullVersionPurchase=false;
 #endif
 #ifdef _DURANGO
 	// Allowed to not have achievements in the menu
 	removeControl( &m_buttons[(int)eControl_Achievements], false );
+	removeControl( &m_buttons[(int)eControl_LceLive], false );
 	// Not allowed to exit from a Xbox One game from the game - have to use the Home button
 	//removeControl( &m_buttons[(int)eControl_Exit], false );
 	m_bWaitingForDLCInfo=false;
@@ -237,10 +246,14 @@ void UIScene_MainMenu::handleReload()
 	removeControl( &m_buttons[(int)eControl_Exit], false );
 	// We don't have a way to display trophies/achievements, so remove the button
 	removeControl( &m_buttons[(int)eControl_Achievements], false );
+	removeControl( &m_buttons[(int)eControl_LceLive], false );
 #endif
 #ifdef _DURANGO
 	// Allowed to not have achievements in the menu
 	removeControl( &m_buttons[(int)eControl_Achievements], false );
+	removeControl( &m_buttons[(int)eControl_LceLive], false );
+#elif !defined(_WINDOWS64) || defined(MINECRAFT_SERVER_BUILD)
+	removeControl( &m_buttons[(int)eControl_LceLive], false );
 #endif
 }
 
@@ -341,10 +354,16 @@ void UIScene_MainMenu::handlePress(F64 controlId, F64 childId)
 	case eControl_Achievements:
 		//CD - Added for audio
 		ui.PlayUISFX(eSFX_Press);
-
 		m_eAction=eAction_RunAchievements;
 		signInReturnedFunc = &UIScene_MainMenu::Achievements_SignInReturned;
 		break;
+	case eControl_LceLive:
+		//CD - Added for audio
+		ui.PlayUISFX(eSFX_Press);
+#if defined(_WINDOWS64) && !defined(MINECRAFT_SERVER_BUILD)
+		ui.NavigateToScene(m_iPad, eUIScene_LceLive);
+#endif
+		return;
 	case eControl_HelpAndOptions:
 		//CD - Added for audio
 		ui.PlayUISFX(eSFX_Press);
diff --git a/Minecraft.Client/Common/UI/UIScene_MainMenu.h b/Minecraft.Client/Common/UI/UIScene_MainMenu.h
index 2b49a44b..34d66de5 100644
--- a/Minecraft.Client/Common/UI/UIScene_MainMenu.h
+++ b/Minecraft.Client/Common/UI/UIScene_MainMenu.h
@@ -12,6 +12,7 @@ private:
 		eControl_Achievements,
 		eControl_HelpAndOptions,
 		eControl_UnlockOrDLC,
+		eControl_LceLive,
 #ifndef _DURANGO
 		eControl_Exit,
 #else
@@ -37,6 +38,7 @@ private:
 		UI_MAP_ELEMENT( m_buttons[(int)eControl_Achievements], "Button3")
 		UI_MAP_ELEMENT( m_buttons[(int)eControl_HelpAndOptions], "Button4")
 		UI_MAP_ELEMENT( m_buttons[(int)eControl_UnlockOrDLC], "Button5")
+		UI_MAP_ELEMENT( m_buttons[(int)eControl_LceLive], "Button7")
 #ifndef _DURANGO
 		UI_MAP_ELEMENT( m_buttons[(int)eControl_Exit], "Button6")
 #else
diff --git a/Minecraft.Client/Windows64/Windows64_LceLive.cpp b/Minecraft.Client/Windows64/Windows64_LceLive.cpp
new file mode 100644
index 00000000..4d1be18d
--- /dev/null
+++ b/Minecraft.Client/Windows64/Windows64_LceLive.cpp
@@ -0,0 +1,973 @@
+#include "stdafx.h"
+
+#ifdef _WINDOWS64
+
+#include "Windows64_LceLive.h"
+
+#include "Windows64_Xuid.h"
+#include "../../Minecraft.World/StringHelpers.h"
+#include "../../Minecraft.Server/vendor/nlohmann/json.hpp"
+
+#include <Windows.h>
+#include <wincrypt.h>
+#include <winhttp.h>
+
+#include <cstdio>
+#include <string>
+#include <vector>
+
+namespace
+{
+	using Json = nlohmann::json;
+
+	enum class ERequestType
+	{
+		None,
+		StartLink,
+		Poll,
+		Refresh,
+		Logout,
+	};
+
+	struct AuthSession
+	{
+		bool valid;
+		std::string accountId;
+		std::string username;
+		std::string displayName;
+		std::string accessToken;
+		std::string refreshToken;
+	};
+
+	struct PendingLink
+	{
+		bool active;
+		std::string deviceCode;
+		std::string userCode;
+		std::string verificationUri;
+		std::string verificationUriComplete;
+		ULONGLONG nextPollAt;
+	};
+
+	struct RequestContext
+	{
+		ERequestType type;
+		std::string path;
+		std::string body;
+	};
+
+	struct CompletedRequest
+	{
+		ERequestType type;
+		bool transportOk;
+		DWORD httpStatus;
+		std::string responseBody;
+	};
+
+	struct RuntimeState
+	{
+		bool initialized;
+		CRITICAL_SECTION lock;
+		bool requestInFlight;
+		bool completedReady;
+		bool sessionRefreshInFlight;
+		HANDLE workerThread;
+		RequestContext request;
+		CompletedRequest completed;
+		AuthSession session;
+		PendingLink pendingLink;
+		std::string lastError;
+	};
+
+	RuntimeState g_state = {};
+	INIT_ONCE g_initializeOnce = INIT_ONCE_STATIC_INIT;
+	INIT_ONCE g_authBlobPathOnce = INIT_ONCE_STATIC_INIT;
+	char g_authBlobPath[MAX_PATH] = {};
+
+	bool BuildExeRelativePath(const char *fileName, char *outPath, size_t outPathSize)
+	{
+		if (fileName == nullptr || outPath == nullptr || outPathSize == 0)
+			return false;
+
+		outPath[0] = 0;
+
+		char exePath[MAX_PATH] = {};
+		DWORD len = GetModuleFileNameA(nullptr, exePath, MAX_PATH);
+		if (len == 0 || len >= MAX_PATH)
+			return false;
+
+		char *lastSlash = strrchr(exePath, '\\');
+		if (lastSlash != nullptr)
+			*(lastSlash + 1) = 0;
+
+		if (strcpy_s(outPath, outPathSize, exePath) != 0)
+			return false;
+		if (strcat_s(outPath, outPathSize, fileName) != 0)
+			return false;
+
+		return true;
+	}
+
+	std::wstring Utf8ToWide(const std::string &text)
+	{
+		if (text.empty())
+			return L"";
+
+		const int length = MultiByteToWideChar(CP_UTF8, 0, text.c_str(), static_cast<int>(text.size()), nullptr, 0);
+		if (length <= 0)
+			return convStringToWstring(text);
+
+		std::wstring result;
+		result.resize(static_cast<size_t>(length));
+		MultiByteToWideChar(CP_UTF8, 0, text.c_str(), static_cast<int>(text.size()), &result[0], length);
+		return result;
+	}
+
+	std::string WideToUtf8(const std::wstring &text)
+	{
+		if (text.empty())
+			return std::string();
+
+		const int length = WideCharToMultiByte(CP_UTF8, 0, text.c_str(), static_cast<int>(text.size()), nullptr, 0, nullptr, nullptr);
+		if (length <= 0)
+			return std::string(wstringtochararray(text));
+
+		std::string result;
+		result.resize(static_cast<size_t>(length));
+		WideCharToMultiByte(CP_UTF8, 0, text.c_str(), static_cast<int>(text.size()), &result[0], length, nullptr, nullptr);
+		return result;
+	}
+
+	std::string JsonStringOrEmpty(const Json &object, const char *key)
+	{
+		const Json::const_iterator it = object.find(key);
+		if (it == object.end() || !it->is_string())
+			return std::string();
+		return it->get<std::string>();
+	}
+
+	std::string ParseErrorMessage(const std::string &responseBody, const std::string &fallback);
+
+	void TrimTrailingSlashes(std::string *value)
+	{
+		if (value == nullptr)
+			return;
+
+		while (!value->empty() && (value->back() == '/' || value->back() == '\\' || value->back() == '\r' || value->back() == '\n' || value->back() == ' ' || value->back() == '\t'))
+			value->pop_back();
+	}
+
+	std::string BuildDeviceId()
+	{
+		const unsigned long long xuid = static_cast<unsigned long long>(Win64Xuid::ResolvePersistentXuid());
+		char buffer[64] = {};
+		sprintf_s(buffer, "win64-%016llX", xuid);
+		return buffer;
+	}
+
+	std::string BuildDeviceName()
+	{
+		wchar_t computerName[MAX_COMPUTERNAME_LENGTH + 1] = {};
+		DWORD size = MAX_COMPUTERNAME_LENGTH + 1;
+		if (GetComputerNameW(computerName, &size))
+		{
+			const std::wstring displayName = L"MCLCE Windows64 (" + std::wstring(computerName) + L")";
+			return WideToUtf8(displayName);
+		}
+
+		return "MCLCE Windows64";
+	}
+
+	std::string GetApiBaseUrl()
+	{
+		char envValue[512] = {};
+		const DWORD envLength = GetEnvironmentVariableA("LCELIVE_API_BASE_URL", envValue, static_cast<DWORD>(sizeof(envValue)));
+		if (envLength > 0 && envLength < sizeof(envValue))
+		{
+			std::string value(envValue);
+			TrimTrailingSlashes(&value);
+			return value;
+		}
+
+		char configPath[MAX_PATH] = {};
+		if (BuildExeRelativePath("lcelive.properties", configPath, sizeof(configPath)))
+		{
+			FILE *file = nullptr;
+			if (fopen_s(&file, configPath, "rb") == 0 && file != nullptr)
+			{
+				char line[512] = {};
+				while (fgets(line, sizeof(line), file) != nullptr)
+				{
+					std::string currentLine(line);
+					while (!currentLine.empty() &&
+						(currentLine[currentLine.size() - 1] == '\n' || currentLine[currentLine.size() - 1] == '\r'))
+					{
+						currentLine.erase(currentLine.size() - 1);
+					}
+
+					const size_t equalsIndex = currentLine.find('=');
+					if (equalsIndex == std::string::npos)
+						continue;
+
+					if (currentLine.substr(0, equalsIndex) == "api_base_url")
+					{
+						fclose(file);
+						std::string value = currentLine.substr(equalsIndex + 1);
+						TrimTrailingSlashes(&value);
+						return value;
+					}
+				}
+
+				fclose(file);
+			}
+		}
+
+		std::string fallback = "http://localhost:5187";
+		TrimTrailingSlashes(&fallback);
+		return fallback;
+	}
+
+	std::string BuildHttpFailureMessage(DWORD httpStatus, const std::string &responseBody, const std::string &fallback)
+	{
+		const std::string parsed = ParseErrorMessage(responseBody, std::string());
+		if (!parsed.empty())
+			return parsed;
+
+		switch (httpStatus)
+		{
+		case 404:
+			return "LCELive start request returned HTTP 404. Check the API base URL and port.";
+		case 500:
+			return "LCELive API returned HTTP 500 while creating a device link.";
+		case 502:
+		case 503:
+		case 504:
+			return "LCELive API is unavailable right now.";
+		default:
+			break;
+		}
+
+		char buffer[96] = {};
+		sprintf_s(buffer, "LCELive start request failed with HTTP %lu.", static_cast<unsigned long>(httpStatus));
+		return fallback.empty() ? std::string(buffer) : std::string(buffer);
+	}
+
+	bool ReadFileBytes(const char *path, std::vector<unsigned char> *outBytes)
+	{
+		if (path == nullptr || outBytes == nullptr)
+			return false;
+
+		FILE *file = nullptr;
+		if (fopen_s(&file, path, "rb") != 0 || file == nullptr)
+			return false;
+
+		if (fseek(file, 0, SEEK_END) != 0)
+		{
+			fclose(file);
+			return false;
+		}
+
+		const long fileSize = ftell(file);
+		if (fileSize <= 0)
+		{
+			fclose(file);
+			return false;
+		}
+
+		if (fseek(file, 0, SEEK_SET) != 0)
+		{
+			fclose(file);
+			return false;
+		}
+
+		outBytes->resize(static_cast<size_t>(fileSize));
+		const size_t readCount = fread(outBytes->data(), 1, outBytes->size(), file);
+		fclose(file);
+		return readCount == outBytes->size();
+	}
+
+	bool WriteFileBytes(const char *path, const unsigned char *data, size_t size)
+	{
+		if (path == nullptr || data == nullptr || size == 0)
+			return false;
+
+		FILE *file = nullptr;
+		if (fopen_s(&file, path, "wb") != 0 || file == nullptr)
+			return false;
+
+		const size_t writeCount = fwrite(data, 1, size, file);
+		fclose(file);
+		return writeCount == size;
+	}
+
+	bool ProtectString(const std::string &plainText, std::vector<unsigned char> *outEncrypted)
+	{
+		if (outEncrypted == nullptr)
+			return false;
+
+		DATA_BLOB inputBlob = {};
+		inputBlob.pbData = reinterpret_cast<BYTE *>(const_cast<char *>(plainText.data()));
+		inputBlob.cbData = static_cast<DWORD>(plainText.size());
+
+		DATA_BLOB outputBlob = {};
+		if (!CryptProtectData(&inputBlob, L"LCELive", nullptr, nullptr, nullptr, CRYPTPROTECT_UI_FORBIDDEN, &outputBlob))
+			return false;
+
+		outEncrypted->assign(outputBlob.pbData, outputBlob.pbData + outputBlob.cbData);
+		LocalFree(outputBlob.pbData);
+		return true;
+	}
+
+	bool UnprotectBytes(const std::vector<unsigned char> &encrypted, std::string *outPlainText)
+	{
+		if (outPlainText == nullptr || encrypted.empty())
+			return false;
+
+		DATA_BLOB inputBlob = {};
+		inputBlob.pbData = const_cast<BYTE *>(encrypted.data());
+		inputBlob.cbData = static_cast<DWORD>(encrypted.size());
+
+		DATA_BLOB outputBlob = {};
+		if (!CryptUnprotectData(&inputBlob, nullptr, nullptr, nullptr, nullptr, CRYPTPROTECT_UI_FORBIDDEN, &outputBlob))
+			return false;
+
+		outPlainText->assign(reinterpret_cast<const char *>(outputBlob.pbData), reinterpret_cast<const char *>(outputBlob.pbData) + outputBlob.cbData);
+		LocalFree(outputBlob.pbData);
+		return true;
+	}
+
+	const char *GetAuthBlobPath()
+	{
+		InitOnceExecuteOnce(&g_authBlobPathOnce,
+			[](PINIT_ONCE, PVOID, PVOID *) -> BOOL
+			{
+				BuildExeRelativePath("lcelive_auth.dat", g_authBlobPath, sizeof(g_authBlobPath));
+				return TRUE;
+			},
+			nullptr,
+			nullptr);
+		return g_authBlobPath;
+	}
+
+	void SaveAuthSessionLocked()
+	{
+		if (!g_state.session.valid)
+		{
+			DeleteFileA(GetAuthBlobPath());
+			return;
+		}
+
+		Json sessionJson;
+		sessionJson["version"] = 1;
+		sessionJson["accountId"] = g_state.session.accountId;
+		sessionJson["username"] = g_state.session.username;
+		sessionJson["displayName"] = g_state.session.displayName;
+		sessionJson["accessToken"] = g_state.session.accessToken;
+		sessionJson["refreshToken"] = g_state.session.refreshToken;
+
+		std::vector<unsigned char> encrypted;
+		if (!ProtectString(sessionJson.dump(), &encrypted))
+		{
+			app.DebugPrintf("LCELive: failed to protect auth blob for local storage\n");
+			return;
+		}
+
+		if (!WriteFileBytes(GetAuthBlobPath(), encrypted.data(), encrypted.size()))
+			app.DebugPrintf("LCELive: failed to write auth blob to disk\n");
+	}
+
+	void ClearSessionLocked()
+	{
+		g_state.session = {};
+		g_state.pendingLink = {};
+		g_state.lastError.clear();
+		DeleteFileA(GetAuthBlobPath());
+	}
+
+	void LoadPersistedSessionLocked()
+	{
+		std::vector<unsigned char> encrypted;
+		if (!ReadFileBytes(GetAuthBlobPath(), &encrypted))
+			return;
+
+		std::string decrypted;
+		if (!UnprotectBytes(encrypted, &decrypted))
+		{
+			app.DebugPrintf("LCELive: unable to decrypt stored auth state, clearing local blob\n");
+			DeleteFileA(GetAuthBlobPath());
+			return;
+		}
+
+		const Json sessionJson = Json::parse(decrypted, nullptr, false);
+		if (!sessionJson.is_object())
+		{
+			app.DebugPrintf("LCELive: stored auth state is invalid JSON, clearing local blob\n");
+			DeleteFileA(GetAuthBlobPath());
+			return;
+		}
+
+		g_state.session.refreshToken = JsonStringOrEmpty(sessionJson, "refreshToken");
+		if (g_state.session.refreshToken.empty())
+		{
+			DeleteFileA(GetAuthBlobPath());
+			g_state.session = {};
+			return;
+		}
+
+		g_state.session.valid = true;
+		g_state.session.accountId = JsonStringOrEmpty(sessionJson, "accountId");
+		g_state.session.username = JsonStringOrEmpty(sessionJson, "username");
+		g_state.session.displayName = JsonStringOrEmpty(sessionJson, "displayName");
+		g_state.session.accessToken = JsonStringOrEmpty(sessionJson, "accessToken");
+	}
+
+	bool CrackUrl(const std::wstring &baseUrl, URL_COMPONENTSW *outComponents, std::vector<wchar_t> *hostBuffer, std::vector<wchar_t> *pathBuffer)
+	{
+		if (outComponents == nullptr || hostBuffer == nullptr || pathBuffer == nullptr)
+			return false;
+
+		hostBuffer->assign(256, 0);
+		pathBuffer->assign(2048, 0);
+
+		ZeroMemory(outComponents, sizeof(*outComponents));
+		outComponents->dwStructSize = sizeof(*outComponents);
+		outComponents->lpszHostName = hostBuffer->data();
+		outComponents->dwHostNameLength = static_cast<DWORD>(hostBuffer->size());
+		outComponents->lpszUrlPath = pathBuffer->data();
+		outComponents->dwUrlPathLength = static_cast<DWORD>(pathBuffer->size());
+
+		return WinHttpCrackUrl(baseUrl.c_str(), static_cast<DWORD>(baseUrl.length()), 0, outComponents) == TRUE;
+	}
+
+	bool PerformJsonRequest(const RequestContext &request, DWORD *outStatus, std::string *outResponseBody)
+	{
+		if (outStatus == nullptr || outResponseBody == nullptr)
+			return false;
+
+		*outStatus = 0;
+		outResponseBody->clear();
+
+		const std::string baseUrlUtf8 = GetApiBaseUrl();
+		const std::wstring baseUrl = Utf8ToWide(baseUrlUtf8);
+		URL_COMPONENTSW components = {};
+		std::vector<wchar_t> hostBuffer;
+		std::vector<wchar_t> pathBuffer;
+		if (!CrackUrl(baseUrl, &components, &hostBuffer, &pathBuffer))
+		{
+			app.DebugPrintf("LCELive: WinHttpCrackUrl failed for '%s'\n", baseUrlUtf8.c_str());
+			return false;
+		}
+
+		std::wstring fullPath = components.lpszUrlPath != nullptr
+			? std::wstring(components.lpszUrlPath, components.dwUrlPathLength)
+			: std::wstring();
+		if (!request.path.empty())
+			fullPath += Utf8ToWide(request.path);
+		if (fullPath.empty())
+			fullPath = L"/";
+
+		const bool secure = components.nScheme == INTERNET_SCHEME_HTTPS;
+
+		HINTERNET session = WinHttpOpen(L"MCLCE-LceLive/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
+		if (session == nullptr)
+			return false;
+
+		WinHttpSetTimeouts(session, 5000, 5000, 10000, 10000);
+
+		const std::wstring hostWide(components.lpszHostName, components.dwHostNameLength);
+		HINTERNET connection = WinHttpConnect(session, hostWide.c_str(), components.nPort, 0);
+		if (connection == nullptr)
+		{
+			WinHttpCloseHandle(session);
+			return false;
+		}
+
+		const wchar_t *verb = request.body.empty() ? L"GET" : L"POST";
+		HINTERNET requestHandle = WinHttpOpenRequest(connection, verb, fullPath.c_str(), nullptr, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, secure ? WINHTTP_FLAG_SECURE : 0);
+		if (requestHandle == nullptr)
+		{
+			WinHttpCloseHandle(connection);
+			WinHttpCloseHandle(session);
+			return false;
+		}
+
+		const wchar_t *headers = request.body.empty()
+			? L"Accept: application/json\r\n"
+			: L"Content-Type: application/json\r\nAccept: application/json\r\n";
+		LPVOID sendBuffer = WINHTTP_NO_REQUEST_DATA;
+		DWORD sendSize = 0;
+		if (!request.body.empty())
+		{
+			sendBuffer = const_cast<char *>(request.body.data());
+			sendSize = static_cast<DWORD>(request.body.size());
+		}
+
+		const BOOL sendOk = WinHttpSendRequest(requestHandle, headers, -1L, sendBuffer, sendSize, sendSize, 0);
+		if (!sendOk || !WinHttpReceiveResponse(requestHandle, nullptr))
+		{
+			WinHttpCloseHandle(requestHandle);
+			WinHttpCloseHandle(connection);
+			WinHttpCloseHandle(session);
+			return false;
+		}
+
+		DWORD statusCode = 0;
+		DWORD statusCodeSize = sizeof(statusCode);
+		if (!WinHttpQueryHeaders(requestHandle, WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER, WINHTTP_HEADER_NAME_BY_INDEX, &statusCode, &statusCodeSize, WINHTTP_NO_HEADER_INDEX))
+		{
+			WinHttpCloseHandle(requestHandle);
+			WinHttpCloseHandle(connection);
+			WinHttpCloseHandle(session);
+			return false;
+		}
+
+		std::string responseBody;
+		for (;;)
+		{
+			DWORD bytesAvailable = 0;
+			if (!WinHttpQueryDataAvailable(requestHandle, &bytesAvailable))
+				break;
+			if (bytesAvailable == 0)
+				break;
+
+			std::vector<char> buffer(bytesAvailable);
+			DWORD bytesRead = 0;
+			if (!WinHttpReadData(requestHandle, buffer.data(), bytesAvailable, &bytesRead))
+				break;
+
+			responseBody.append(buffer.data(), buffer.data() + bytesRead);
+		}
+
+		*outStatus = statusCode;
+		*outResponseBody = responseBody;
+
+		WinHttpCloseHandle(requestHandle);
+		WinHttpCloseHandle(connection);
+		WinHttpCloseHandle(session);
+		return true;
+	}
+
+	std::string ParseErrorMessage(const std::string &responseBody, const std::string &fallback)
+	{
+		if (responseBody.empty())
+			return fallback;
+
+		const Json responseJson = Json::parse(responseBody, nullptr, false);
+		if (!responseJson.is_object())
+			return fallback;
+
+		const std::string message = JsonStringOrEmpty(responseJson, "message");
+		return message.empty() ? fallback : message;
+	}
+
+	DWORD WINAPI RequestThreadProc(LPVOID)
+	{
+		RequestContext request = {};
+		EnterCriticalSection(&g_state.lock);
+		request = g_state.request;
+		LeaveCriticalSection(&g_state.lock);
+
+		CompletedRequest completed = {};
+		completed.type = request.type;
+		completed.transportOk = PerformJsonRequest(request, &completed.httpStatus, &completed.responseBody);
+
+		EnterCriticalSection(&g_state.lock);
+		g_state.completed = completed;
+		g_state.completedReady = true;
+		g_state.requestInFlight = false;
+		LeaveCriticalSection(&g_state.lock);
+		return 0;
+	}
+
+	bool QueueRequestLocked(ERequestType type, const std::string &path, const std::string &body)
+	{
+		if (g_state.requestInFlight)
+			return false;
+
+		if (g_state.workerThread != nullptr)
+		{
+			WaitForSingleObject(g_state.workerThread, INFINITE);
+			CloseHandle(g_state.workerThread);
+			g_state.workerThread = nullptr;
+		}
+
+		g_state.request = {};
+		g_state.request.type = type;
+		g_state.request.path = path;
+		g_state.request.body = body;
+		g_state.requestInFlight = true;
+		g_state.completedReady = false;
+		g_state.workerThread = CreateThread(nullptr, 0, &RequestThreadProc, nullptr, 0, nullptr);
+		if (g_state.workerThread == nullptr)
+		{
+			g_state.requestInFlight = false;
+			g_state.lastError = "Unable to create LCELive worker thread.";
+			return false;
+		}
+
+		return true;
+	}
+
+	void QueueSessionRefreshLocked()
+	{
+		if (!g_state.session.valid || g_state.session.refreshToken.empty() || g_state.requestInFlight)
+			return;
+
+		Json requestJson;
+		requestJson["refreshToken"] = g_state.session.refreshToken;
+		if (QueueRequestLocked(ERequestType::Refresh, "/api/auth/refresh", requestJson.dump()))
+			g_state.sessionRefreshInFlight = true;
+	}
+
+	BOOL CALLBACK InitializeRuntimeState(PINIT_ONCE, PVOID, PVOID *)
+	{
+		InitializeCriticalSection(&g_state.lock);
+
+		EnterCriticalSection(&g_state.lock);
+		g_state.initialized = true;
+		LoadPersistedSessionLocked();
+		QueueSessionRefreshLocked();
+		LeaveCriticalSection(&g_state.lock);
+
+		return TRUE;
+	}
+
+	void EnsureInitialized()
+	{
+		InitOnceExecuteOnce(&g_initializeOnce, &InitializeRuntimeState, nullptr, nullptr);
+	}
+
+	void ApplyStartLinkResponseLocked(const CompletedRequest &completed)
+	{
+		if (!completed.transportOk)
+		{
+			g_state.lastError = "Unable to contact LCELive.";
+			return;
+		}
+
+		if (completed.httpStatus < 200 || completed.httpStatus >= 300)
+		{
+			g_state.lastError = BuildHttpFailureMessage(completed.httpStatus, completed.responseBody, "LCELive rejected the device-link request.");
+			return;
+		}
+
+		const Json responseJson = Json::parse(completed.responseBody, nullptr, false);
+		if (!responseJson.is_object())
+		{
+			g_state.lastError = "LCELive returned an invalid device-link response.";
+			return;
+		}
+
+		g_state.pendingLink = {};
+		g_state.pendingLink.active = true;
+		g_state.pendingLink.deviceCode = JsonStringOrEmpty(responseJson, "deviceCode");
+		g_state.pendingLink.userCode = JsonStringOrEmpty(responseJson, "userCode");
+		g_state.pendingLink.verificationUri = JsonStringOrEmpty(responseJson, "verificationUri");
+		g_state.pendingLink.verificationUriComplete = JsonStringOrEmpty(responseJson, "verificationUriComplete");
+
+		int intervalSeconds = 5;
+		const Json::const_iterator intervalIt = responseJson.find("intervalSeconds");
+		if (intervalIt != responseJson.end() && intervalIt->is_number_integer())
+			intervalSeconds = intervalIt->get<int>();
+		if (intervalSeconds < 1)
+			intervalSeconds = 5;
+
+		g_state.pendingLink.nextPollAt = GetTickCount64() + (static_cast<ULONGLONG>(intervalSeconds) * 1000ULL);
+		g_state.lastError.clear();
+	}
+
+	void ApplyPollResponseLocked(const CompletedRequest &completed)
+	{
+		if (!g_state.pendingLink.active)
+			return;
+
+		if (!completed.transportOk)
+		{
+			g_state.pendingLink.active = false;
+			g_state.lastError = "LCELive polling failed. Press A to request a new code.";
+			return;
+		}
+
+		if (completed.httpStatus < 200 || completed.httpStatus >= 300)
+		{
+			g_state.pendingLink.active = false;
+			g_state.lastError = ParseErrorMessage(completed.responseBody, "LCELive rejected the device poll.");
+			return;
+		}
+
+		const Json responseJson = Json::parse(completed.responseBody, nullptr, false);
+		if (!responseJson.is_object())
+		{
+			g_state.pendingLink.active = false;
+			g_state.lastError = "LCELive returned an invalid poll response.";
+			return;
+		}
+
+		const std::string status = JsonStringOrEmpty(responseJson, "status");
+		const bool isLinked = responseJson.contains("isLinked") && responseJson["isLinked"].is_boolean() && responseJson["isLinked"].get<bool>();
+		if (isLinked)
+		{
+			const Json::const_iterator accountIt = responseJson.find("account");
+			if (accountIt == responseJson.end() || !accountIt->is_object())
+			{
+				g_state.pendingLink.active = false;
+				g_state.lastError = "LCELive linked the device but omitted account details.";
+				return;
+			}
+
+			g_state.session.valid = true;
+			g_state.session.accountId = JsonStringOrEmpty(*accountIt, "accountId");
+			g_state.session.username = JsonStringOrEmpty(*accountIt, "username");
+			g_state.session.displayName = JsonStringOrEmpty(*accountIt, "displayName");
+			g_state.session.accessToken = JsonStringOrEmpty(responseJson, "accessToken");
+			g_state.session.refreshToken = JsonStringOrEmpty(responseJson, "refreshToken");
+			g_state.pendingLink = {};
+			g_state.lastError.clear();
+			SaveAuthSessionLocked();
+			return;
+		}
+
+		if (status == "pending")
+		{
+			g_state.pendingLink.nextPollAt = GetTickCount64() + 5000ULL;
+			g_state.lastError.clear();
+			return;
+		}
+
+		g_state.pendingLink.active = false;
+		if (status == "expired")
+			g_state.lastError = "That device code expired. Press A to request a new one.";
+		else
+			g_state.lastError = "LCELive returned an unexpected poll status.";
+	}
+
+	void ApplyRefreshResponseLocked(const CompletedRequest &completed)
+	{
+		g_state.sessionRefreshInFlight = false;
+		if (!g_state.session.valid)
+			return;
+
+		if (!completed.transportOk)
+		{
+			g_state.lastError = "Unable to reach LCELive. Using the cached local sign-in for now.";
+			return;
+		}
+
+		if (completed.httpStatus < 200 || completed.httpStatus >= 300)
+		{
+			ClearSessionLocked();
+			g_state.lastError = "Saved LCELive sign-in expired. Press A to link this device again.";
+			return;
+		}
+
+		const Json responseJson = Json::parse(completed.responseBody, nullptr, false);
+		if (!responseJson.is_object())
+		{
+			g_state.lastError = "LCELive returned an invalid session refresh response.";
+			return;
+		}
+
+		const Json::const_iterator accountIt = responseJson.find("account");
+		if (accountIt == responseJson.end() || !accountIt->is_object())
+		{
+			ClearSessionLocked();
+			g_state.lastError = "LCELive refresh omitted account details. Link this device again.";
+			return;
+		}
+
+		const std::string refreshedAccessToken = JsonStringOrEmpty(responseJson, "accessToken");
+		const std::string refreshedRefreshToken = JsonStringOrEmpty(responseJson, "refreshToken");
+		if (refreshedAccessToken.empty() || refreshedRefreshToken.empty())
+		{
+			ClearSessionLocked();
+			g_state.lastError = "LCELive refresh returned incomplete credentials. Link this device again.";
+			return;
+		}
+
+		g_state.session.valid = true;
+		g_state.session.accountId = JsonStringOrEmpty(*accountIt, "accountId");
+		g_state.session.username = JsonStringOrEmpty(*accountIt, "username");
+		g_state.session.displayName = JsonStringOrEmpty(*accountIt, "displayName");
+		g_state.session.accessToken = refreshedAccessToken;
+		g_state.session.refreshToken = refreshedRefreshToken;
+		g_state.lastError.clear();
+		SaveAuthSessionLocked();
+	}
+
+	void IntegrateCompletedRequestLocked()
+	{
+		if (!g_state.completedReady)
+			return;
+
+		const CompletedRequest completed = g_state.completed;
+		g_state.completedReady = false;
+
+		if (g_state.workerThread != nullptr)
+		{
+			WaitForSingleObject(g_state.workerThread, INFINITE);
+			CloseHandle(g_state.workerThread);
+			g_state.workerThread = nullptr;
+		}
+
+		switch (completed.type)
+		{
+		case ERequestType::StartLink:
+			ApplyStartLinkResponseLocked(completed);
+			break;
+		case ERequestType::Poll:
+			ApplyPollResponseLocked(completed);
+			break;
+		case ERequestType::Refresh:
+			ApplyRefreshResponseLocked(completed);
+			break;
+		case ERequestType::Logout:
+		default:
+			break;
+		}
+	}
+
+	std::wstring BuildStatusMessageLocked()
+	{
+		if (g_state.session.valid)
+		{
+			std::wstring message;
+			message += L"Signed in as:\r\n";
+			message += Utf8ToWide(g_state.session.displayName);
+			if (!g_state.session.username.empty())
+			{
+				message += L" (@";
+				message += Utf8ToWide(g_state.session.username);
+				message += L")";
+			}
+
+			message += L"\r\nThis device is linked locally for LCELive features.";
+			if (g_state.sessionRefreshInFlight)
+				message += L"\r\nRefreshing the saved session with LCELive...";
+
+			message += L"\r\nPress A to sign out on this device.";
+			return message;
+		}
+
+		if (g_state.pendingLink.active)
+		{
+			std::wstring message;
+			message += L"Go to:\r\n";
+			message += Utf8ToWide(g_state.pendingLink.verificationUri);
+			message += L"\r\nEnter code:\r\n";
+			message += Utf8ToWide(g_state.pendingLink.userCode);
+			message += L"\r\nThis screen will keep checking until the link completes.";
+			return message;
+		}
+
+		return L"Sign-in is optional. Offline play is unchanged.\r\nPress A to request a device code.\r\nThen visit the LCELive link page and enter the code shown here.";
+	}
+}
+
+namespace Win64LceLive
+{
+	void Tick()
+	{
+		EnsureInitialized();
+
+		EnterCriticalSection(&g_state.lock);
+		IntegrateCompletedRequestLocked();
+		if (g_state.pendingLink.active && !g_state.requestInFlight && GetTickCount64() >= g_state.pendingLink.nextPollAt)
+			QueueRequestLocked(ERequestType::Poll, "/api/auth/device/poll/" + g_state.pendingLink.deviceCode, std::string());
+		LeaveCriticalSection(&g_state.lock);
+	}
+
+	Snapshot GetSnapshot()
+	{
+		EnsureInitialized();
+		Tick();
+
+		Snapshot snapshot = {};
+		EnterCriticalSection(&g_state.lock);
+		snapshot.requestInFlight = g_state.requestInFlight;
+		snapshot.hasError = !g_state.lastError.empty();
+		snapshot.errorMessage = Utf8ToWide(g_state.lastError);
+		snapshot.statusMessage = BuildStatusMessageLocked();
+
+		if (g_state.session.valid)
+		{
+			snapshot.state = EClientState::SignedIn;
+			snapshot.accountDisplayName = Utf8ToWide(g_state.session.displayName);
+			snapshot.accountUsername = Utf8ToWide(g_state.session.username);
+			snapshot.accountId = Utf8ToWide(g_state.session.accountId);
+		}
+		else if (g_state.pendingLink.active)
+		{
+			snapshot.state = g_state.requestInFlight ? EClientState::Polling : EClientState::LinkPending;
+			snapshot.verificationUri = Utf8ToWide(g_state.pendingLink.verificationUri);
+			snapshot.verificationUriComplete = Utf8ToWide(g_state.pendingLink.verificationUriComplete);
+			snapshot.userCode = Utf8ToWide(g_state.pendingLink.userCode);
+		}
+		else if (g_state.requestInFlight)
+		{
+			snapshot.state = EClientState::StartingLink;
+		}
+		else
+		{
+			snapshot.state = EClientState::SignedOut;
+		}
+		LeaveCriticalSection(&g_state.lock);
+
+		return snapshot;
+	}
+
+	bool StartDeviceLink()
+	{
+		EnsureInitialized();
+
+		EnterCriticalSection(&g_state.lock);
+		IntegrateCompletedRequestLocked();
+		if (g_state.requestInFlight || g_state.session.valid)
+		{
+			LeaveCriticalSection(&g_state.lock);
+			return false;
+		}
+
+		g_state.pendingLink = {};
+		g_state.lastError.clear();
+
+		Json requestJson;
+		requestJson["deviceId"] = BuildDeviceId();
+		requestJson["deviceName"] = BuildDeviceName();
+
+		const bool queued = QueueRequestLocked(ERequestType::StartLink, "/api/auth/device/start", requestJson.dump());
+		LeaveCriticalSection(&g_state.lock);
+		return queued;
+	}
+
+	bool SignOut()
+	{
+		EnsureInitialized();
+
+		EnterCriticalSection(&g_state.lock);
+		IntegrateCompletedRequestLocked();
+		if (g_state.requestInFlight)
+		{
+			LeaveCriticalSection(&g_state.lock);
+			return false;
+		}
+
+		if (!g_state.session.valid && !g_state.pendingLink.active)
+		{
+			LeaveCriticalSection(&g_state.lock);
+			return false;
+		}
+
+		const std::string refreshToken = g_state.session.refreshToken;
+		ClearSessionLocked();
+		if (!refreshToken.empty() && !g_state.requestInFlight)
+		{
+			Json requestJson;
+			requestJson["refreshToken"] = refreshToken;
+			QueueRequestLocked(ERequestType::Logout, "/api/auth/logout", requestJson.dump());
+		}
+		LeaveCriticalSection(&g_state.lock);
+		return true;
+	}
+}
+
+#endif
diff --git a/Minecraft.Client/Windows64/Windows64_LceLive.h b/Minecraft.Client/Windows64/Windows64_LceLive.h
new file mode 100644
index 00000000..5b117c5e
--- /dev/null
+++ b/Minecraft.Client/Windows64/Windows64_LceLive.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#ifdef _WINDOWS64
+
+#include <string>
+
+namespace Win64LceLive
+{
+	enum class EClientState
+	{
+		SignedOut,
+		StartingLink,
+		LinkPending,
+		Polling,
+		SignedIn,
+	};
+
+	struct Snapshot
+	{
+		EClientState state;
+		bool requestInFlight;
+		bool hasError;
+		std::wstring accountDisplayName;
+		std::wstring accountUsername;
+		std::wstring accountId;
+		std::wstring verificationUri;
+		std::wstring verificationUriComplete;
+		std::wstring userCode;
+		std::wstring statusMessage;
+		std::wstring errorMessage;
+	};
+
+	void Tick();
+	Snapshot GetSnapshot();
+	bool StartDeviceLink();
+	bool SignOut();
+}
+
+#endif
diff --git a/Minecraft.Client/cmake/sources/Windows.cmake b/Minecraft.Client/cmake/sources/Windows.cmake
index e07f46e3..2ee2b37a 100644
--- a/Minecraft.Client/cmake/sources/Windows.cmake
+++ b/Minecraft.Client/cmake/sources/Windows.cmake
@@ -150,6 +150,8 @@ set(_MINECRAFT_CLIENT_WINDOWS_COMMON_UI_SCENES_FRONTEND_MENU_SCREENS
   "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_Intro.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_JoinMenu.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_JoinMenu.h"
+  "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_LceLive.cpp"
+  "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_LceLive.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_LaunchMoreOptionsMenu.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_LaunchMoreOptionsMenu.h"
   "${CMAKE_CURRENT_SOURCE_DIR}/Common/UI/UIScene_LeaderboardsMenu.cpp"
@@ -340,6 +342,8 @@ set(_MINECRAFT_CLIENT_WINDOWS_WINDOWS64
   "${BASE_DIR}/Resource.h"
   "${BASE_DIR}/Windows64_App.cpp"
   "${BASE_DIR}/Windows64_App.h"
+  "${BASE_DIR}/Windows64_LceLive.cpp"
+  "${BASE_DIR}/Windows64_LceLive.h"
   "${BASE_DIR}/Windows64_UIController.cpp"
   "${BASE_DIR}/Windows64_UIController.h"
   "${BASE_DIR}/KeyboardMouseInput.cpp"
diff --git a/Minecraft.Server/CMakeLists.txt b/Minecraft.Server/CMakeLists.txt
index 52e5826e..a1d9686e 100644
--- a/Minecraft.Server/CMakeLists.txt
+++ b/Minecraft.Server/CMakeLists.txt
@@ -37,9 +37,11 @@ set_target_properties(Minecraft.Server PROPERTIES
 
 target_link_libraries(Minecraft.Server PRIVATE
   Minecraft.World
+  crypt32
   d3d11
   d3dcompiler
   XInput9_1_0
+  winhttp
   wsock32
   legacy_stdio_definitions
   $<$<CONFIG:Debug>: # Debug 4J libraries
diff --git a/Minecraft.Server/cmake/sources/Common.cmake b/Minecraft.Server/cmake/sources/Common.cmake
index 58ae26ce..7894da22 100644
--- a/Minecraft.Server/cmake/sources/Common.cmake
+++ b/Minecraft.Server/cmake/sources/Common.cmake
@@ -208,6 +208,7 @@ set(_MINECRAFT_SERVER_COMMON_ROOT
   "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_InventoryMenu.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_JoinMenu.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_Keyboard.cpp"
+  "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_LceLive.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_LanguageSelector.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_LaunchMoreOptionsMenu.cpp"
   "${CMAKE_CURRENT_SOURCE_DIR}/../Minecraft.Client/Common/UI/UIScene_LeaderboardsMenu.cpp"
diff --git a/tools/repack_media_arc.py b/tools/repack_media_arc.py
new file mode 100644
index 00000000..6940d851
--- /dev/null
+++ b/tools/repack_media_arc.py
@@ -0,0 +1,150 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import argparse
+import shutil
+import struct
+from dataclasses import dataclass
+from pathlib import Path
+
+
+@dataclass
+class Entry:
+    raw_name: str
+    ptr: int
+    size: int
+    data: bytes
+
+    @property
+    def logical_name(self) -> str:
+        return self.raw_name[1:] if self.raw_name.startswith("*") else self.raw_name
+
+
+def read_utf(data: bytes, offset: int) -> tuple[str, int]:
+    (utf_len,) = struct.unpack_from(">H", data, offset)
+    offset += 2
+    raw = data[offset : offset + utf_len]
+    offset += utf_len
+    return raw.decode("utf-8"), offset
+
+
+def write_utf(value: str) -> bytes:
+    raw = value.encode("utf-8")
+    if len(raw) > 0xFFFF:
+        raise ValueError(f"archive entry name is too long: {value}")
+    return struct.pack(">H", len(raw)) + raw
+
+
+def load_archive(path: Path) -> list[Entry]:
+    blob = path.read_bytes()
+    offset = 0
+    (count,) = struct.unpack_from(">i", blob, offset)
+    offset += 4
+
+    headers: list[tuple[str, int, int]] = []
+    for _ in range(count):
+        raw_name, offset = read_utf(blob, offset)
+        ptr, size = struct.unpack_from(">ii", blob, offset)
+        offset += 8
+        headers.append((raw_name, ptr, size))
+
+    entries: list[Entry] = []
+    for raw_name, ptr, size in headers:
+        entries.append(Entry(raw_name=raw_name, ptr=ptr, size=size, data=blob[ptr : ptr + size]))
+    return entries
+
+
+def build_archive(entries: list[Entry]) -> bytes:
+    header_parts: list[bytes] = [struct.pack(">i", len(entries))]
+    data_offset = 4
+
+    encoded_names = [write_utf(entry.raw_name) for entry in entries]
+    for encoded_name, entry in zip(encoded_names, entries, strict=True):
+        data_offset += len(encoded_name) + 8
+
+    payload_parts: list[bytes] = []
+    current_ptr = data_offset
+    for encoded_name, entry in zip(encoded_names, entries, strict=True):
+        header_parts.append(encoded_name)
+        header_parts.append(struct.pack(">ii", current_ptr, len(entry.data)))
+        payload_parts.append(entry.data)
+        current_ptr += len(entry.data)
+
+    return b"".join(header_parts + payload_parts)
+
+
+def apply_overlays(entries: list[Entry], overlays: dict[str, Path]) -> list[str]:
+    replaced: list[str] = []
+    by_name = {entry.logical_name: entry for entry in entries}
+
+    for logical_name, overlay_path in overlays.items():
+        if not overlay_path.exists():
+            raise FileNotFoundError(f"overlay file does not exist: {overlay_path}")
+
+        overlay_data = overlay_path.read_bytes()
+        existing = by_name.get(logical_name)
+        if existing is None:
+            entries.append(Entry(raw_name=logical_name, ptr=0, size=len(overlay_data), data=overlay_data))
+        else:
+            if existing.raw_name.startswith("*"):
+                raise ValueError(
+                    f"refusing to replace compressed archive entry '{existing.raw_name}' with raw data"
+                )
+            existing.data = overlay_data
+            existing.size = len(overlay_data)
+        replaced.append(logical_name)
+
+    return replaced
+
+
+def parse_overlay_args(values: list[str]) -> dict[str, Path]:
+    overlays: dict[str, Path] = {}
+    for value in values:
+        name, separator, path = value.partition("=")
+        if not separator:
+            raise ValueError(f"overlay must be NAME=PATH, got: {value}")
+        overlays[name] = Path(path)
+    return overlays
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Overlay selected files into a MediaWindows64.arc archive.")
+    parser.add_argument("input", type=Path, help="Existing archive to read")
+    parser.add_argument("output", type=Path, help="Archive path to write")
+    parser.add_argument(
+        "--overlay",
+        action="append",
+        default=[],
+        metavar="NAME=PATH",
+        help="Replace or add archive entry NAME with the bytes from PATH",
+    )
+    parser.add_argument(
+        "--backup",
+        action="store_true",
+        help="Write a .bak copy of the output file before replacing it when the output already exists",
+    )
+    args = parser.parse_args()
+
+    overlays = parse_overlay_args(args.overlay)
+    entries = load_archive(args.input)
+    touched = apply_overlays(entries, overlays)
+    rebuilt = build_archive(entries)
+
+    args.output.parent.mkdir(parents=True, exist_ok=True)
+    if args.backup and args.output.exists():
+        backup_path = args.output.with_suffix(args.output.suffix + ".bak")
+        shutil.copy2(args.output, backup_path)
+
+    args.output.write_bytes(rebuilt)
+
+    print(f"wrote {args.output}")
+    print(f"entries: {len(entries)}")
+    if touched:
+        print("overlays:")
+        for logical_name in touched:
+            print(f"  {logical_name}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())