diff --git a/CMakeLists.txt b/CMakeLists.txt
index 36dbf12c73..a6f2ea7c7e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -712,6 +712,10 @@ add_library(Common STATIC
 	Common/Render/Text/draw_text_uwp.h
 	Common/System/Display.cpp
 	Common/System/Display.h
+	Common/System/System.h
+	Common/System/NativeApp.h
+	Common/System/Request.cpp
+	Common/System/Request.h
 	Common/Thread/Channel.h
 	Common/Thread/ParallelLoop.cpp
 	Common/Thread/ParallelLoop.h
diff --git a/Common/Common.vcxproj b/Common/Common.vcxproj
index c066494c66..3fabaafa64 100644
--- a/Common/Common.vcxproj
+++ b/Common/Common.vcxproj
@@ -550,6 +550,7 @@
     <ClInclude Include="Swap.h" />
     <ClInclude Include="SysError.h" />
     <ClInclude Include="System\Display.h" />
+    <ClInclude Include="System\Request.h" />
     <ClInclude Include="System\NativeApp.h" />
     <ClInclude Include="System\System.h" />
     <ClInclude Include="Thread\Barrier.h" />
@@ -1005,6 +1006,7 @@
     <ClCompile Include="OSVersion.cpp" />
     <ClCompile Include="StringUtils.cpp" />
     <ClCompile Include="System\Display.cpp" />
+    <ClCompile Include="System\Request.cpp" />
     <ClCompile Include="Thread\ParallelLoop.cpp" />
     <ClCompile Include="Thread\ThreadManager.cpp" />
     <ClCompile Include="Thread\ThreadUtil.cpp" />
diff --git a/Common/Common.vcxproj.filters b/Common/Common.vcxproj.filters
index cce4e7656a..879e3495b8 100644
--- a/Common/Common.vcxproj.filters
+++ b/Common/Common.vcxproj.filters
@@ -494,6 +494,9 @@
     <ClInclude Include="..\ext\basis_universal\basisu_transcoder_uastc.h">
       <Filter>ext\basis_universal</Filter>
     </ClInclude>
+    <ClInclude Include="System\Request.h">
+      <Filter>System</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="ABI.cpp" />
@@ -920,6 +923,9 @@
     <ClCompile Include="..\ext\basis_universal\basisu_transcoder.cpp">
       <Filter>ext\basis_universal</Filter>
     </ClCompile>
+    <ClCompile Include="System\Request.cpp">
+      <Filter>System</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Crypto">
diff --git a/Common/System/NativeApp.h b/Common/System/NativeApp.h
index 6788642eb4..bb0c7af962 100644
--- a/Common/System/NativeApp.h
+++ b/Common/System/NativeApp.h
@@ -23,9 +23,6 @@ void NativeGetAppInfo(std::string *app_dir_name, std::string *app_nice_name, boo
 // Generic host->C++ messaging, used for functionality like system-native popup input boxes.
 void NativeMessageReceived(const char *message, const char *value);
 
-// This is used to communicate back and thread requested input box strings.
-void NativeInputBoxReceived(std::function<void(bool, const std::string &)> cb, bool result, const std::string &value);
-
 // Easy way for the Java side to ask the C++ side for configuration options, such as
 // the rotation lock which must be controlled from Java on Android.
 // It is currently not called on non-Android platforms.
diff --git a/Common/System/Request.cpp b/Common/System/Request.cpp
new file mode 100644
index 0000000000..883514d8da
--- /dev/null
+++ b/Common/System/Request.cpp
@@ -0,0 +1,72 @@
+#include "Common/System/Request.h"
+#include "Common/System/System.h"
+#include "Common/Log.h"
+
+RequestManager g_requestManager;
+
+const char *RequestTypeAsString(SystemRequestType type) {
+	switch (type) {
+	case SystemRequestType::INPUT_TEXT_MODAL: return "INPUT_TEXT_MODAL";
+	default: return "N/A";
+	}
+}
+
+bool RequestManager::MakeSystemRequest(SystemRequestType type, RequestCallback callback, const std::string &param1, const std::string &param2) {
+	int requestId = idCounter_++;
+	if (!System_MakeRequest(type, requestId, param1, param2)) {
+		return false;
+	}
+
+	if (!callback) {
+		// We don't expect a response, this is a one-directional request. We're thus done.
+		return true;
+	}
+
+	std::lock_guard<std::mutex> guard(callbackMutex_);
+	callbackMap_[requestId] = callback;
+	return true;
+}
+
+void RequestManager::PostSystemSuccess(int requestId, const char *responseString, int responseValue) {
+	std::lock_guard<std::mutex> guard(callbackMutex_);
+	auto iter = callbackMap_.find(requestId);
+	if (iter == callbackMap_.end()) {
+		ERROR_LOG(SYSTEM, "PostSystemSuccess: Unexpected request ID %d (responseString=%s)", requestId, responseString);
+		return;
+	}
+
+	std::lock_guard<std::mutex> responseGuard(responseMutex_);
+	PendingResponse response;
+	response.callback = iter->second;
+	response.responseString = responseString;
+	response.responseValue = responseValue;
+	pendingResponses_.push_back(response);
+}
+
+void RequestManager::PostSystemFailure(int requestId) {
+	std::lock_guard<std::mutex> guard(callbackMutex_);
+	auto iter = callbackMap_.find(requestId);
+	if (iter == callbackMap_.end()) {
+		ERROR_LOG(SYSTEM, "PostSystemFailure: Unexpected request ID %d", requestId);
+		return;
+	}
+	callbackMap_.erase(iter);
+}
+
+void RequestManager::ProcessRequests() {
+	std::lock_guard<std::mutex> guard(responseMutex_);
+	for (auto &iter : pendingResponses_) {
+		if (iter.callback) {
+			iter.callback(iter.responseString.c_str(), iter.responseValue);
+		}
+	}
+	pendingResponses_.clear();
+}
+
+void RequestManager::Clear() {
+	std::lock_guard<std::mutex> guard(callbackMutex_);
+	std::lock_guard<std::mutex> responseGuard(responseMutex_);
+
+	pendingResponses_.clear();
+	callbackMap_.clear();
+}
diff --git a/Common/System/Request.h b/Common/System/Request.h
new file mode 100644
index 0000000000..19afe99721
--- /dev/null
+++ b/Common/System/Request.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include <vector>
+#include <mutex>
+#include <map>
+#include <functional>
+
+#include "Common/System/System.h"
+
+typedef std::function<void(const char *responseString, int responseValue)> RequestCallback;
+
+// Platforms often have to process requests asynchronously, on wildly different threads.
+// (Especially Android...)
+// This acts as bridge and buffer.
+class RequestManager {
+public:
+	// These requests are to be handled by platform implementations.
+	// The callback you pass in will be called on the main thread later.
+	bool MakeSystemRequest(SystemRequestType type, RequestCallback callback, const std::string &param1, const std::string &param2);
+
+	// Called by the platform implementation, when it's finished with a request.
+	void PostSystemSuccess(int requestId, const char *responseString, int responseValue = 0);
+	void PostSystemFailure(int requestId);
+
+	// This must be called every frame from the beginning of NativeUpdate().
+	// This will call the callback of any finished requests.
+	void ProcessRequests();
+
+	// Unclear if we need this...
+	void Clear();
+
+private:
+	struct PendingRequest {
+		SystemRequestType type;
+		RequestCallback callback;
+	};
+
+	std::map<int, RequestCallback> callbackMap_;
+	std::mutex callbackMutex_;
+
+	struct PendingResponse {
+		std::string responseString;
+		int responseValue;
+		RequestCallback callback;
+	};
+
+	int idCounter_ = 0;
+	std::vector<PendingResponse> pendingResponses_;
+	std::mutex responseMutex_;
+};
+
+const char *RequestTypeAsString(SystemRequestType type);
+
+extern RequestManager g_requestManager;
+
+// Wrappers for easy requests.
+// NOTE: Semantics have changed - this no longer calls the callback on cancellation.
+inline void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, RequestCallback callback) {
+	g_requestManager.MakeSystemRequest(SystemRequestType::INPUT_TEXT_MODAL, callback, title, defaultValue);
+}
diff --git a/Common/System/System.h b/Common/System/System.h
index 8d74f9c270..b0222aeea0 100644
--- a/Common/System/System.h
+++ b/Common/System/System.h
@@ -50,8 +50,20 @@ enum class LaunchUrlType {
 void System_Vibrate(int length_ms);
 void System_ShowFileInFolder(const char *path);
 void System_LaunchUrl(LaunchUrlType urlType, const char *url);
-void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, std::function<void(bool, const std::string &)> cb);
+
+enum class SystemRequestType {
+	INPUT_TEXT_MODAL,
+};
+
+// Implementations are supposed to process the request, and post the response to the g_RequestManager (see Message.h).
+// This is not to be used directly by applications, instead use the g_RequestManager to make the requests.
+// This can return false if it's known that the platform doesn't support the request, the app is supposed to handle
+// or ignore that cleanly.
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2);
+
+// TODO: To be separated into requests, see Request.h, and a way to post "UI messages".
 void System_SendMessage(const char *command, const char *parameter);
+
 PermissionStatus System_GetPermissionStatus(SystemPermission permission);
 void System_AskForPermission(SystemPermission permission);
 
diff --git a/Core/Dialog/PSPOskDialog.cpp b/Core/Dialog/PSPOskDialog.cpp
index e6e1ccafc4..bfbc545f67 100755
--- a/Core/Dialog/PSPOskDialog.cpp
+++ b/Core/Dialog/PSPOskDialog.cpp
@@ -22,7 +22,7 @@
 #include "Common/Math/math_util.h"
 #include "Common/Data/Encoding/Utf8.h"
 #include "Common/Serialize/SerializeFuncs.h"
-#include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/Serialize/Serializer.h"
 
 #include "Core/Dialog/PSPOskDialog.h"
@@ -892,14 +892,14 @@ int PSPOskDialog::NativeKeyboard() {
 			defaultText.assign(u"VALUE");
 
 		// There's already ConvertUCS2ToUTF8 in this file. Should we use that instead of the global ones?
-		System_InputBoxGetString(::ConvertUCS2ToUTF8(titleText), ::ConvertUCS2ToUTF8(defaultText), [&](bool result, const std::string &value) {
+		System_InputBoxGetString(::ConvertUCS2ToUTF8(titleText), ::ConvertUCS2ToUTF8(defaultText), [&](const std::string &value, int iValue) {
 			std::lock_guard<std::mutex> guard(nativeMutex_);
 			if (nativeStatus_ != PSPOskNativeStatus::WAITING) {
 				return;
 			}
 
 			nativeValue_ = value;
-			nativeStatus_ = result ? PSPOskNativeStatus::SUCCESS : PSPOskNativeStatus::FAILURE;
+			nativeStatus_ = iValue ? PSPOskNativeStatus::SUCCESS : PSPOskNativeStatus::FAILURE;
 		});
 	} else if (nativeStatus_ == PSPOskNativeStatus::SUCCESS) {
 		inputChars = ConvertUTF8ToUCS2(nativeValue_);
diff --git a/Qt/QtMain.cpp b/Qt/QtMain.cpp
index 3571c615ca..ba475e5141 100644
--- a/Qt/QtMain.cpp
+++ b/Qt/QtMain.cpp
@@ -34,7 +34,7 @@
 #endif
 
 #include "Common/System/NativeApp.h"
-#include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/GPU/OpenGL/GLFeatures.h"
 #include "Common/Math/math_util.h"
 #include "Common/Profiler/Profiler.h"
@@ -58,6 +58,8 @@ MainUI *emugl = nullptr;
 static float refreshRate = 60.f;
 static int browseFileEvent = -1;
 static int browseFolderEvent = -1;
+static int inputBoxEvent = -1;
+
 QTCamera *qtcamera = nullptr;
 MainWindow *g_mainWindow;
 
@@ -273,6 +275,57 @@ void System_Notify(SystemNotification notification) {
 	}
 }
 
+// TODO: Find a better version to pass parameters to HandleCustomEvent.
+static std::string g_param1;
+static std::string g_param2;
+static int g_requestId;
+
+bool MainUI::HandleCustomEvent(QEvent *e) {
+	if (e->type() == browseFileEvent) {
+		QString fileName = QFileDialog::getOpenFileName(nullptr, "Load ROM", g_Config.currentDirectory.c_str(), "PSP ROMs (*.iso *.cso *.pbp *.elf *.zip *.ppdmp)");
+		if (QFile::exists(fileName)) {
+			QDir newPath;
+			g_Config.currentDirectory = Path(newPath.filePath(fileName).toStdString());
+			g_Config.Save("browseFileEvent");
+
+			NativeMessageReceived("boot", fileName.toStdString().c_str());
+		}
+	} else if (e->type() == browseFolderEvent) {
+		auto mm = GetI18NCategory("MainMenu");
+		QString fileName = QFileDialog::getExistingDirectory(nullptr, mm->T("Choose folder"), g_Config.currentDirectory.c_str());
+		if (QDir(fileName).exists()) {
+			NativeMessageReceived("browse_folderSelect", fileName.toStdString().c_str());
+		}
+	} else if (e->type() == inputBoxEvent) {
+	    QString title = QString::fromStdString(g_param1);
+	    QString defaultValue = QString::fromStdString(g_param2);
+	    QString text = emugl->InputBoxGetQString(title, defaultValue);
+	    if (text.isEmpty()) {
+	        g_requestManager.PostSystemFailure(g_requestId);
+	    } else {
+	        g_requestManager.PostSystemSuccess(g_requestId, text.toStdString().c_str());
+	    }
+	} else {
+		return false;
+	}
+	return true;
+}
+
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) {
+	switch (type) {
+	case SystemRequestType::INPUT_TEXT_MODAL:
+	{
+		g_requestId = requestId;
+		g_param1 = param1;
+		g_param2 = param2;
+		QCoreApplication::postEvent(emugl, new QEvent((QEvent::Type)inputBoxEvent));
+		return true;
+	}
+	default:
+		return false;
+	}
+}
+
 void System_SendMessage(const char *command, const char *parameter) {
 	if (!strcmp(command, "finish")) {
 		qApp->exit(0);
@@ -305,15 +358,6 @@ void System_Toast(const char *text) {}
 void System_AskForPermission(SystemPermission permission) {}
 PermissionStatus System_GetPermissionStatus(SystemPermission permission) { return PERMISSION_STATUS_GRANTED; }
 
-void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, std::function<void(bool, const std::string &)> cb) {
-	QString text = emugl->InputBoxGetQString(QString::fromStdString(title), QString::fromStdString(defaultValue));
-	if (text.isEmpty()) {
-		NativeInputBoxReceived(cb, false, "");
-	} else {
-		NativeInputBoxReceived(cb, true, text.toStdString());
-	}
-}
-
 void System_Vibrate(int length_ms) {
 	if (length_ms == -1 || length_ms == -3)
 		length_ms = 50;
@@ -355,6 +399,7 @@ static int mainInternal(QApplication &a) {
 
 	browseFileEvent = QEvent::registerEventType();
 	browseFolderEvent = QEvent::registerEventType();
+	inputBoxEvent = QEvent::registerEventType();
 
 	int retval = a.exec();
 	delete emugl;
@@ -566,23 +611,8 @@ bool MainUI::event(QEvent *e) {
 		break;
 
 	default:
-		if (e->type() == browseFileEvent) {
-			QString fileName = QFileDialog::getOpenFileName(nullptr, "Load ROM", g_Config.currentDirectory.c_str(), "PSP ROMs (*.iso *.cso *.pbp *.elf *.zip *.ppdmp)");
-			if (QFile::exists(fileName)) {
-				QDir newPath;
-				g_Config.currentDirectory = Path(newPath.filePath(fileName).toStdString());
-				g_Config.Save("browseFileEvent");
-
-				NativeMessageReceived("boot", fileName.toStdString().c_str());
-			}
-			break;
-		} else if (e->type() == browseFolderEvent) {
-			auto mm = GetI18NCategory("MainMenu");
-			QString fileName = QFileDialog::getExistingDirectory(nullptr, mm->T("Choose folder"), g_Config.currentDirectory.c_str());
-			if (QDir(fileName).exists()) {
-				NativeMessageReceived("browse_folderSelect", fileName.toStdString().c_str());
-			}
-		} else {
+		// Can't switch on dynamic event types.
+		if (!HandleCustomEvent(e)) {
 			return QWidget::event(e);
 		}
 	}
diff --git a/Qt/QtMain.h b/Qt/QtMain.h
index 639806bcf5..39cce11f77 100644
--- a/Qt/QtMain.h
+++ b/Qt/QtMain.h
@@ -140,6 +140,7 @@ protected:
 	void EmuThreadJoin();
 
 private:
+	bool HandleCustomEvent(QEvent *e);
 	QtGLGraphicsContext *graphicsContext;
 
 	float xscale, yscale;
diff --git a/README.md b/README.md
index 0aaed77a12..5c0e51a5b1 100644
--- a/README.md
+++ b/README.md
@@ -7,11 +7,9 @@ Additional code by many contributors, see the Credits screen
 
 Originally released under the GPL 2.0 (and later) in November 2012
 
-Official website:
-https://www.ppsspp.org/
+Official website: https://www.ppsspp.org/
 
-Discord:
-https://discord.gg/5NJB6dD
+Discord: https://discord.gg/5NJB6dD
 
 No BIOS file required to play, PPSSPP is an "HLE" emulator.  Default settings balance good compatibility and speed.
 
@@ -19,9 +17,11 @@ To contribute, see [the development page](https://www.ppsspp.org/development.htm
 
 For the latest source code, see [our GitHub page](https://github.com/hrydgard/ppsspp).
 
+For documentation of all kinds (usage, reference, development), see the [documentation on the main website](https://www.ppsspp.org/docs)
+
 For build instructions and other development tutorials, see [the wiki](https://github.com/hrydgard/ppsspp/wiki).
 
-If you want to download regularly updated builds for Android, Windows x86 and x64, proceed to this [page](https://buildbot.orphis.net/ppsspp/)
+If you want to download regularly updated builds for Android, Windows x86 and x64, [visit Orphis' buildbot](https://buildbot.orphis.net/ppsspp/)
 
 For game compatibility, see [community compatibility feedback](https://report.ppsspp.org/games).
 
@@ -412,4 +412,4 @@ Credit goes to:
 [#16709]: https://github.com/hrydgard/ppsspp/issues/16709 "Correct some shader errors in reporting"
 [#16708]: https://github.com/hrydgard/ppsspp/issues/16708 "Additional fixes from both our reports and Play reports"
 [#16703]: https://github.com/hrydgard/ppsspp/issues/16703 "Minor fixes based on the latest Google Play report"
-[#16706]: https://github.com/hrydgard/ppsspp/issues/16706 "softgpu: Fix lighting with 0 exp"
\ No newline at end of file
+[#16706]: https://github.com/hrydgard/ppsspp/issues/16706 "softgpu: Fix lighting with 0 exp"
diff --git a/SDL/SDLMain.cpp b/SDL/SDLMain.cpp
index f59a2dd22a..3bda836e98 100644
--- a/SDL/SDLMain.cpp
+++ b/SDL/SDLMain.cpp
@@ -166,6 +166,8 @@ void System_Vibrate(int length_ms) {
 	// Ignore on PC
 }
 
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) { return false; }
+
 void System_SendMessage(const char *command, const char *parameter) {
 	if (!strcmp(command, "toggle_fullscreen")) {
 		g_ToggleFullScreenNextFrame = true;
diff --git a/UI/ChatScreen.cpp b/UI/ChatScreen.cpp
index 277185b3e5..d62470666e 100644
--- a/UI/ChatScreen.cpp
+++ b/UI/ChatScreen.cpp
@@ -10,7 +10,7 @@
 
 #include "Common/Data/Text/I18n.h"
 #include "Common/Data/Encoding/Utf8.h"
-#include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Core/Config.h"
 #include "Core/System.h"
 #include "Core/HLE/proAdhoc.h"
@@ -97,7 +97,7 @@ UI::EventReturn ChatMenu::OnSubmit(UI::EventParams &e) {
 	sendChat(chat);
 #elif PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Chat"), "", [](bool result, const std::string &value) {
+	System_InputBoxGetString(n->T("Chat"), "", [](const std::string &value, int) {
 		sendChat(value);
 	});
 #endif
@@ -181,10 +181,8 @@ void ChatMenu::Update() {
 #if defined(USING_WIN_UI)
 	// Could remove the fullscreen check here, it works now.
 	if (promptInput_ && g_Config.bBypassOSKWithKeyboard && !g_Config.UseFullScreen()) {
-		System_InputBoxGetString(n->T("Chat"), n->T("Chat Here"), [](bool result, const std::string &value) {
-			if (result) {
-				sendChat(value);
-			}
+		System_InputBoxGetString(n->T("Chat"), n->T("Chat Here"), [](const std::string &value, int) {
+			sendChat(value);
 		});
 		promptInput_ = false;
 	}
diff --git a/UI/GameSettingsScreen.cpp b/UI/GameSettingsScreen.cpp
index ded0d26d52..43f7ed44a5 100644
--- a/UI/GameSettingsScreen.cpp
+++ b/UI/GameSettingsScreen.cpp
@@ -30,7 +30,7 @@
 #include "Common/VR/PPSSPPVR.h"
 
 #include "Common/System/Display.h"  // Only to check screen aspect ratio with pixel_yres/pixel_xres
-#include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/Battery/Battery.h"
 #include "Common/System/NativeApp.h"
 #include "Common/Data/Color/RGBAUtil.h"
@@ -1564,10 +1564,8 @@ UI::EventReturn GameSettingsScreen::OnAudioDevice(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeQuickChat0(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Enter Quick Chat 1"), g_Config.sQuickChat0, [](bool result, const std::string &value) {
-		if (result) {
-			g_Config.sQuickChat0 = value;
-		}
+	System_InputBoxGetString(n->T("Enter Quick Chat 1"), g_Config.sQuickChat0, [](const std::string &value, int) {
+		g_Config.sQuickChat0 = value;
 	});
 #endif
 	return UI::EVENT_DONE;
@@ -1576,10 +1574,8 @@ UI::EventReturn GameSettingsScreen::OnChangeQuickChat0(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeQuickChat1(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Enter Quick Chat 2"), g_Config.sQuickChat1, [](bool result, const std::string &value) {
-		if (result) {
-			g_Config.sQuickChat1 = value;
-		}
+	System_InputBoxGetString(n->T("Enter Quick Chat 2"), g_Config.sQuickChat1, [](const std::string &value, int) {
+		g_Config.sQuickChat1 = value;
 	});
 #endif
 	return UI::EVENT_DONE;
@@ -1588,10 +1584,8 @@ UI::EventReturn GameSettingsScreen::OnChangeQuickChat1(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeQuickChat2(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Enter Quick Chat 3"), g_Config.sQuickChat2, [](bool result, const std::string &value) {
-		if (result) {
-			g_Config.sQuickChat2 = value;
-		}
+	System_InputBoxGetString(n->T("Enter Quick Chat 3"), g_Config.sQuickChat2, [](const std::string &value, int) {
+		g_Config.sQuickChat2 = value;
 	});
 #endif
 	return UI::EVENT_DONE;
@@ -1600,10 +1594,8 @@ UI::EventReturn GameSettingsScreen::OnChangeQuickChat2(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeQuickChat3(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Enter Quick Chat 4"), g_Config.sQuickChat3, [](bool result, const std::string &value) {
-		if (result) {
-			g_Config.sQuickChat3 = value;
-		}
+	System_InputBoxGetString(n->T("Enter Quick Chat 4"), g_Config.sQuickChat3, [](const std::string &value, int) {
+		g_Config.sQuickChat3 = value;
 	});
 #endif
 	return UI::EVENT_DONE;
@@ -1612,10 +1604,8 @@ UI::EventReturn GameSettingsScreen::OnChangeQuickChat3(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeQuickChat4(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Enter Quick Chat 5"), g_Config.sQuickChat4, [](bool result, const std::string &value) {
-		if (result) {
-			g_Config.sQuickChat4 = value;
-		}
+	System_InputBoxGetString(n->T("Enter Quick Chat 5"), g_Config.sQuickChat4, [](const std::string &value, int) {
+		g_Config.sQuickChat4 = value;
 	});
 #endif
 	return UI::EVENT_DONE;
@@ -1624,10 +1614,8 @@ UI::EventReturn GameSettingsScreen::OnChangeQuickChat4(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeNickname(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	auto n = GetI18NCategory("Networking");
-	System_InputBoxGetString(n->T("Enter a new PSP nickname"), g_Config.sNickName, [](bool result, const std::string &value) {
-		if (result) {
-			g_Config.sNickName = StripSpaces(value);
-		}
+	System_InputBoxGetString(n->T("Enter a new PSP nickname"), g_Config.sNickName, [](const std::string &value, int) {
+		g_Config.sNickName = StripSpaces(value);
 	});
 #endif
 	return UI::EVENT_DONE;
@@ -1723,10 +1711,8 @@ UI::EventReturn GameSettingsScreen::OnSysInfo(UI::EventParams &e) {
 UI::EventReturn GameSettingsScreen::OnChangeSearchFilter(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || defined(__ANDROID__)
 	auto se = GetI18NCategory("Search");
-	System_InputBoxGetString(se->T("Search term"), searchFilter_, [](bool result, const std::string &value) {
-		if (result) {
-			NativeMessageReceived("gameSettings_search", StripSpaces(value).c_str());
-		}
+	System_InputBoxGetString(se->T("Search term"), searchFilter_, [](const std::string &value, int) {
+		NativeMessageReceived("gameSettings_search", StripSpaces(value).c_str());
 	});
 #else
 	if (!System_GetPropertyBool(SYSPROP_HAS_KEYBOARD))
@@ -2098,10 +2084,8 @@ UI::EventReturn HostnameSelectScreen::OnDeleteAllClick(UI::EventParams &e) {
 UI::EventReturn HostnameSelectScreen::OnEditClick(UI::EventParams& e) {
 	auto n = GetI18NCategory("Networking");
 #if PPSSPP_PLATFORM(ANDROID)
-	System_InputBoxGetString(n->T("proAdhocServer Address:"), addrView_->GetText(), [this](bool result, const std::string& value) {
-		if (result) {
-		    addrView_->SetText(value);
-		}
+	System_InputBoxGetString(n->T("proAdhocServer Address:"), addrView_->GetText(), [this](const std::string& value, int) {
+	    addrView_->SetText(value);
 	});
 #endif
 	return UI::EVENT_DONE;
diff --git a/UI/MemStickScreen.cpp b/UI/MemStickScreen.cpp
index 265be6bf68..5bf8c83d6f 100644
--- a/UI/MemStickScreen.cpp
+++ b/UI/MemStickScreen.cpp
@@ -26,6 +26,7 @@
 
 #include "Common/StringUtils.h"
 #include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/System/NativeApp.h"
 #include "Common/System/Display.h"
 #include "Common/Data/Text/I18n.h"
@@ -336,64 +337,62 @@ UI::EventReturn MemStickScreen::SetFolderManually(UI::EventParams &params) {
 	// The old way, from before scoped storage.
 #if PPSSPP_PLATFORM(ANDROID)
 	auto sy = GetI18NCategory("System");
-	System_InputBoxGetString(sy->T("Memory Stick Folder"), g_Config.memStickDirectory.ToString(), [&](bool result, const std::string &value) {
+	System_InputBoxGetString(sy->T("Memory Stick Folder"), g_Config.memStickDirectory.ToString(), [&](const std::string &value, int) {
 		auto sy = GetI18NCategory("System");
 		auto di = GetI18NCategory("Dialog");
 
-		if (result) {
-			std::string newPath = value;
-			size_t pos = newPath.find_last_not_of("/");
-			// Gotta have at least something but a /, and also needs to start with a /.
-			if (newPath.empty() || pos == newPath.npos || newPath[0] != '/') {
-				settingInfo_->Show(sy->T("ChangingMemstickPathInvalid", "That path couldn't be used to save Memory Stick files."), nullptr);
-				return;
-			}
-			if (pos != newPath.size() - 1) {
-				newPath = newPath.substr(0, pos + 1);
-			}
+        std::string newPath = value;
+        size_t pos = newPath.find_last_not_of("/");
+        // Gotta have at least something but a /, and also needs to start with a /.
+        if (newPath.empty() || pos == newPath.npos || newPath[0] != '/') {
+            settingInfo_->Show(sy->T("ChangingMemstickPathInvalid", "That path couldn't be used to save Memory Stick files."), nullptr);
+            return;
+        }
+        if (pos != newPath.size() - 1) {
+            newPath = newPath.substr(0, pos + 1);
+        }
 
-			if (newPath.empty()) {
-				// Reuse below message instead of adding yet another string.
-				System_Toast(sy->T("Path does not exist!"));
-				return;
-			}
+        if (newPath.empty()) {
+            // Reuse below message instead of adding yet another string.
+            System_Toast(sy->T("Path does not exist!"));
+            return;
+        }
 
-			Path pendingMemStickFolder(newPath);
+        Path pendingMemStickFolder(newPath);
 
-			if (!File::Exists(pendingMemStickFolder)) {
-				// Try to fix the path string, apparently some users got used to leaving out the /.
-				if (newPath[0] != '/') {
-					newPath = "/" + newPath;
-				}
+        if (!File::Exists(pendingMemStickFolder)) {
+            // Try to fix the path string, apparently some users got used to leaving out the /.
+            if (newPath[0] != '/') {
+                newPath = "/" + newPath;
+            }
 
-				pendingMemStickFolder = Path(newPath);
-			}
+            pendingMemStickFolder = Path(newPath);
+        }
 
-			if (!File::Exists(pendingMemStickFolder) && pendingMemStickFolder.Type() == PathType::NATIVE) {
-				// Still no path? Try to automatically fix the case.
-				std::string oldNewPath = newPath;
-				FixPathCase(Path(""), newPath, FixPathCaseBehavior::FPC_FILE_MUST_EXIST);
-				if (oldNewPath != newPath) {
-					NOTICE_LOG(IO, "Fixed path case: %s -> %s", oldNewPath.c_str(), newPath.c_str());
-					pendingMemStickFolder = Path(newPath);
-				} else {
-					NOTICE_LOG(IO, "Failed to fix case of path %s (result: %s)", newPath.c_str(), oldNewPath.c_str());
-				}
-			}
+        if (!File::Exists(pendingMemStickFolder) && pendingMemStickFolder.Type() == PathType::NATIVE) {
+            // Still no path? Try to automatically fix the case.
+            std::string oldNewPath = newPath;
+            FixPathCase(Path(""), newPath, FixPathCaseBehavior::FPC_FILE_MUST_EXIST);
+            if (oldNewPath != newPath) {
+                NOTICE_LOG(IO, "Fixed path case: %s -> %s", oldNewPath.c_str(), newPath.c_str());
+                pendingMemStickFolder = Path(newPath);
+            } else {
+                NOTICE_LOG(IO, "Failed to fix case of path %s (result: %s)", newPath.c_str(), oldNewPath.c_str());
+            }
+        }
 
-			if (pendingMemStickFolder == g_Config.memStickDirectory) {
-				// Same directory as before - all good. Nothing to do.
-				TriggerFinish(DialogResult::DR_OK);
-				return;
-			}
+        if (pendingMemStickFolder == g_Config.memStickDirectory) {
+            // Same directory as before - all good. Nothing to do.
+            TriggerFinish(DialogResult::DR_OK);
+            return;
+        }
 
-			if (!File::Exists(pendingMemStickFolder)) {
-				System_Toast(sy->T("Path does not exist!"));
-				return;
-			}
+        if (!File::Exists(pendingMemStickFolder)) {
+            System_Toast(sy->T("Path does not exist!"));
+            return;
+        }
 
-			screenManager()->push(new ConfirmMemstickMoveScreen(pendingMemStickFolder, false));
-		}
+        screenManager()->push(new ConfirmMemstickMoveScreen(pendingMemStickFolder, false));
 	});
 #endif
 	return UI::EVENT_DONE;
diff --git a/UI/NativeApp.cpp b/UI/NativeApp.cpp
index e2c05d2b31..35503efce0 100644
--- a/UI/NativeApp.cpp
+++ b/UI/NativeApp.cpp
@@ -58,8 +58,10 @@
 #include "android/jni/app-android.h"
 
 #include "Common/System/Display.h"
+#include "Common/System/Request.h"
 #include "Common/System/System.h"
 #include "Common/System/NativeApp.h"
+
 #include "Common/Data/Text/I18n.h"
 #include "Common/Input/InputState.h"
 #include "Common/Math/math_util.h"
@@ -148,7 +150,7 @@
 
 #include <Core/HLE/Plugins.h>
 
-ScreenManager *screenManager;
+ScreenManager *g_screenManager;
 std::string config_filename;
 
 // Really need to clean this mess of globals up... but instead I add more :P
@@ -164,15 +166,8 @@ struct PendingMessage {
 	std::string value;
 };
 
-struct PendingInputBox {
-	std::function<void(bool, const std::string &)> cb;
-	bool result;
-	std::string value;
-};
-
 static std::mutex pendingMutex;
 static std::vector<PendingMessage> pendingMessages;
-static std::vector<PendingInputBox> pendingInputBoxes;
 static Draw::DrawContext *g_draw;
 static Draw::Pipeline *colorPipeline;
 static Draw::Pipeline *texColorPipeline;
@@ -443,7 +438,7 @@ void NativeInit(int argc, const char *argv[], const char *savegame_dir, const ch
 	setlocale( LC_ALL, "C" );
 	std::string user_data_path = savegame_dir;
 	pendingMessages.clear();
-	pendingInputBoxes.clear();
+	g_requestManager.Clear();
 
 	// external_dir has all kinds of meanings depending on platform.
 	// on iOS it's even the path to bundled app assets. It's a mess.
@@ -789,19 +784,19 @@ void NativeInit(int argc, const char *argv[], const char *savegame_dir, const ch
 	}
 
 	DEBUG_LOG(SYSTEM, "ScreenManager!");
-	screenManager = new ScreenManager();
+	g_screenManager = new ScreenManager();
 	if (g_Config.memStickDirectory.empty()) {
 		INFO_LOG(SYSTEM, "No memstick directory! Asking for one to be configured.");
-		screenManager->switchScreen(new LogoScreen(AfterLogoScreen::MEMSTICK_SCREEN_INITIAL_SETUP));
+		g_screenManager->switchScreen(new LogoScreen(AfterLogoScreen::MEMSTICK_SCREEN_INITIAL_SETUP));
 	} else if (gotoGameSettings) {
-		screenManager->switchScreen(new LogoScreen(AfterLogoScreen::TO_GAME_SETTINGS));
+		g_screenManager->switchScreen(new LogoScreen(AfterLogoScreen::TO_GAME_SETTINGS));
 	} else if (gotoTouchScreenTest) {
-		screenManager->switchScreen(new MainScreen());
-		screenManager->push(new TouchTestScreen(Path()));
+		g_screenManager->switchScreen(new MainScreen());
+		g_screenManager->push(new TouchTestScreen(Path()));
 	} else if (skipLogo) {
-		screenManager->switchScreen(new EmuScreen(boot_filename));
+		g_screenManager->switchScreen(new EmuScreen(boot_filename));
 	} else {
-		screenManager->switchScreen(new LogoScreen(AfterLogoScreen::DEFAULT));
+		g_screenManager->switchScreen(new LogoScreen(AfterLogoScreen::DEFAULT));
 	}
 
 	// Easy testing
@@ -833,7 +828,7 @@ bool CreateGlobalPipelines();
 bool NativeInitGraphics(GraphicsContext *graphicsContext) {
 	INFO_LOG(SYSTEM, "NativeInitGraphics");
 
-	_assert_(screenManager);
+	_assert_(g_screenManager);
 
 	// We set this now so any resize during init is processed later.
 	resized = false;
@@ -864,10 +859,10 @@ bool NativeInitGraphics(GraphicsContext *graphicsContext) {
 	if (uiContext->Text())
 		uiContext->Text()->SetFont("Tahoma", 20, 0);
 
-	screenManager->setUIContext(uiContext);
-	screenManager->setDrawContext(g_draw);
-	screenManager->setPostRenderCallback(&RenderOverlays, nullptr);
-	screenManager->deviceRestored();
+	g_screenManager->setUIContext(uiContext);
+	g_screenManager->setDrawContext(g_draw);
+	g_screenManager->setPostRenderCallback(&RenderOverlays, nullptr);
+	g_screenManager->deviceRestored();
 
 #ifdef _WIN32
 	winAudioBackend = CreateAudioBackend((AudioBackendType)g_Config.iAudioBackend);
@@ -951,8 +946,8 @@ bool CreateGlobalPipelines() {
 void NativeShutdownGraphics() {
 	INFO_LOG(SYSTEM, "NativeShutdownGraphics");
 
-	if (screenManager) {
-		screenManager->deviceLost();
+	if (g_screenManager) {
+		g_screenManager->deviceLost();
 	}
 
 	if (gpu)
@@ -1062,7 +1057,7 @@ void RenderOverlays(UIContext *dc, void *userdata) {
 
 void NativeRender(GraphicsContext *graphicsContext) {
 	_dbg_assert_(graphicsContext != nullptr);
-	_dbg_assert_(screenManager != nullptr);
+	_dbg_assert_(g_screenManager != nullptr);
 
 	g_GameManager.Update();
 
@@ -1108,19 +1103,19 @@ void NativeRender(GraphicsContext *graphicsContext) {
 	ui_draw2d.PushDrawMatrix(ortho);
 	ui_draw2d_front.PushDrawMatrix(ortho);
 
-	screenManager->getUIContext()->SetTintSaturation(g_Config.fUITint, g_Config.fUISaturation);
+	g_screenManager->getUIContext()->SetTintSaturation(g_Config.fUITint, g_Config.fUISaturation);
 
 	Draw::DebugFlags debugFlags = Draw::DebugFlags::NONE;
 	if (g_Config.bShowGpuProfile)
 		debugFlags |= Draw::DebugFlags::PROFILE_TIMESTAMPS;
 	if (g_Config.bGpuLogProfiler)
 		debugFlags |= Draw::DebugFlags::PROFILE_SCOPES;
-	screenManager->getDrawContext()->SetDebugFlags(debugFlags);
+	g_screenManager->getDrawContext()->SetDebugFlags(debugFlags);
 
 	// All actual rendering happen in here.
-	screenManager->render();
-	if (screenManager->getUIContext()->Text()) {
-		screenManager->getUIContext()->Text()->OncePerFrame();
+	g_screenManager->render();
+	if (g_screenManager->getUIContext()->Text()) {
+		g_screenManager->getUIContext()->Text()->OncePerFrame();
 	}
 
 	if (resized) {
@@ -1142,7 +1137,7 @@ void NativeRender(GraphicsContext *graphicsContext) {
 		}
 
 		graphicsContext->Resize();
-		screenManager->resized();
+		g_screenManager->resized();
 
 		// TODO: Move this to the GraphicsContext objects for each backend.
 #if !PPSSPP_PLATFORM(WINDOWS) && !defined(ANDROID)
@@ -1248,25 +1243,21 @@ void NativeUpdate() {
 	PROFILE_END_FRAME();
 
 	std::vector<PendingMessage> toProcess;
-	std::vector<PendingInputBox> inputToProcess;
 	{
 		std::lock_guard<std::mutex> lock(pendingMutex);
 		toProcess = std::move(pendingMessages);
-		inputToProcess = std::move(pendingInputBoxes);
 		pendingMessages.clear();
-		pendingInputBoxes.clear();
 	}
 
 	for (const auto &item : toProcess) {
 		HandleGlobalMessage(item.msg, item.value);
-		screenManager->sendMessage(item.msg.c_str(), item.value.c_str());
-	}
-	for (const auto &item : inputToProcess) {
-		item.cb(item.result, item.value);
+		g_screenManager->sendMessage(item.msg.c_str(), item.value.c_str());
 	}
 
+	g_requestManager.ProcessRequests();
+
 	g_DownloadManager.Update();
-	screenManager->update();
+	g_screenManager->update();
 
 	g_Discord.Update();
 
@@ -1275,11 +1266,11 @@ void NativeUpdate() {
 
 bool NativeIsAtTopLevel() {
 	// This might need some synchronization?
-	if (!screenManager) {
+	if (!g_screenManager) {
 		ERROR_LOG(SYSTEM, "No screen manager active");
 		return false;
 	}
-	Screen *currentScreen = screenManager->topScreen();
+	Screen *currentScreen = g_screenManager->topScreen();
 	if (currentScreen) {
 		bool top = currentScreen->isTopLevel();
 		INFO_LOG(SYSTEM, "Screen toplevel: %i", (int)top);
@@ -1291,7 +1282,7 @@ bool NativeIsAtTopLevel() {
 }
 
 void NativeTouch(const TouchInput &touch) {
-	if (!screenManager) {
+	if (!g_screenManager) {
 		return;
 	}
 
@@ -1300,7 +1291,7 @@ void NativeTouch(const TouchInput &touch) {
 	if (my_isnan(touch.x) || my_isnan(touch.y)) {
 		return;
 	}
-	screenManager->touch(touch);
+	g_screenManager->touch(touch);
 }
 
 bool NativeKey(const KeyInput &key) {
@@ -1323,10 +1314,10 @@ bool NativeKey(const KeyInput &key) {
 	}
 #endif
 	bool retval = false;
-	if (screenManager)
+	if (g_screenManager)
 	{
 		HLEPlugins::PluginDataKeys[key.keyCode] = (key.flags & KEY_DOWN) ? 1 : 0;
-		retval = screenManager->key(key);
+		retval = g_screenManager->key(key);
 	}
 	return retval;
 }
@@ -1337,7 +1328,7 @@ void NativeAxis(const AxisInput &axis) {
 		return;
 	}
 
-	if (!screenManager) {
+	if (!g_screenManager) {
 		// Too early.
 		return;
 	}
@@ -1346,7 +1337,7 @@ void NativeAxis(const AxisInput &axis) {
 
 	// only do special handling of tilt events if tilt is enabled.
 	HLEPlugins::PluginDataAxis[axis.axisId] = axis.value;
-	screenManager->axis(axis);
+	g_screenManager->axis(axis);
 
 	if (g_Config.iTiltInputType == TILT_NULL) {
 		// if tilt events are disabled, don't do anything special.
@@ -1396,15 +1387,6 @@ void NativeMessageReceived(const char *message, const char *value) {
 	pendingMessages.push_back(pendingMessage);
 }
 
-void NativeInputBoxReceived(std::function<void(bool, const std::string &)> cb, bool result, const std::string &value) {
-	std::lock_guard<std::mutex> lock(pendingMutex);
-	PendingInputBox pendingMessage;
-	pendingMessage.cb = cb;
-	pendingMessage.result = result;
-	pendingMessage.value = value;
-	pendingInputBoxes.push_back(pendingMessage);
-}
-
 void NativeResized() {
 	// NativeResized can come from any thread so we just set a flag, then process it later.
 	VERBOSE_LOG(G3D, "NativeResized - setting flag");
@@ -1420,10 +1402,10 @@ bool NativeIsRestarting() {
 }
 
 void NativeShutdown() {
-	if (screenManager) {
-		screenManager->shutdown();
-		delete screenManager;
-		screenManager = nullptr;
+	if (g_screenManager) {
+		g_screenManager->shutdown();
+		delete g_screenManager;
+		g_screenManager = nullptr;
 	}
 
 #if !PPSSPP_PLATFORM(UWP)
diff --git a/UI/RemoteISOScreen.cpp b/UI/RemoteISOScreen.cpp
index 98cea5ea85..d14c9999d4 100644
--- a/UI/RemoteISOScreen.cpp
+++ b/UI/RemoteISOScreen.cpp
@@ -31,6 +31,7 @@
 #include "Common/Net/Resolve.h"
 #include "Common/Net/URL.h"
 #include "Common/Thread/ThreadUtil.h"
+#include "Common/System/Request.h"
 
 #include "Common/File/PathBrowser.h"
 #include "Common/Data/Format/JSONReader.h"
@@ -38,7 +39,6 @@
 #include "Common/Common.h"
 #include "Common/Log.h"
 #include "Common/StringUtils.h"
-#include "Common/System/System.h"
 #include "Common/TimeUtil.h"
 #include "Core/Config.h"
 #include "Core/System.h"
@@ -643,7 +643,7 @@ void RemoteISOSettingsScreen::CreateViews() {
 UI::EventReturn RemoteISOSettingsScreen::OnClickRemoteServer(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || defined(__ANDROID__)
 	auto ri = GetI18NCategory("RemoteISO");
-	System_InputBoxGetString(ri->T("Remote Server"), g_Config.sLastRemoteISOServer, [](bool result, const std::string &value) {
+	System_InputBoxGetString(ri->T("Remote Server"), g_Config.sLastRemoteISOServer, [](const std::string &value, int) {
 		g_Config.sLastRemoteISOServer = value;
 	});
 #endif
@@ -663,7 +663,7 @@ static void CleanupRemoteISOSubdir() {
 UI::EventReturn RemoteISOSettingsScreen::OnClickRemoteISOSubdir(UI::EventParams &e) {
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || defined(__ANDROID__)
 	auto ri = GetI18NCategory("RemoteISO");
-	System_InputBoxGetString(ri->T("Remote Subdirectory"), g_Config.sRemoteISOSubdir, [](bool result, const std::string &value) {
+	System_InputBoxGetString(ri->T("Remote Subdirectory"), g_Config.sRemoteISOSubdir, [](const std::string &value, int) {
 		g_Config.sRemoteISOSubdir = value;
 		// Apply the cleanup logic, too.
 		CleanupRemoteISOSubdir();
diff --git a/UI/SavedataScreen.cpp b/UI/SavedataScreen.cpp
index 0d04ac02b9..c7ab4b7136 100644
--- a/UI/SavedataScreen.cpp
+++ b/UI/SavedataScreen.cpp
@@ -24,7 +24,7 @@
 #include "Common/Data/Text/I18n.h"
 #include "Common/Math/curves.h"
 #include "Common/System/NativeApp.h"
-#include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/Data/Encoding/Utf8.h"
 #include "Common/UI/Context.h"
 #include "Common/UI/View.h"
@@ -674,8 +674,8 @@ UI::EventReturn SavedataScreen::OnSortClick(UI::EventParams &e) {
 UI::EventReturn SavedataScreen::OnSearch(UI::EventParams &e) {
 	auto di = GetI18NCategory("Dialog");
 #if PPSSPP_PLATFORM(WINDOWS) || defined(USING_QT_UI) || defined(__ANDROID__)
-	System_InputBoxGetString(di->T("Filter"), searchFilter_, [](bool result, const std::string &value) {
-		if (result) {
+	System_InputBoxGetString(di->T("Filter"), searchFilter_, [](const std::string &value, int ivalue) {
+		if (ivalue) {
 			NativeMessageReceived("savedatascreen_search", value.c_str());
 		}
 	});
diff --git a/UWP/CommonUWP/CommonUWP.vcxproj b/UWP/CommonUWP/CommonUWP.vcxproj
index a76a85ef67..f997600744 100644
--- a/UWP/CommonUWP/CommonUWP.vcxproj
+++ b/UWP/CommonUWP/CommonUWP.vcxproj
@@ -376,6 +376,7 @@
     <ClInclude Include="..\..\Common\SysError.h" />
     <ClInclude Include="..\..\Common\System\Display.h" />
     <ClInclude Include="..\..\Common\System\NativeApp.h" />
+    <ClInclude Include="..\..\Common\System\Request.h" />
     <ClInclude Include="..\..\Common\System\System.h" />
     <ClInclude Include="..\..\Common\Thread\Channel.h" />
     <ClInclude Include="..\..\Common\Thread\Promise.h" />
@@ -510,6 +511,7 @@
     <ClCompile Include="..\..\Common\OSVersion.cpp" />
     <ClCompile Include="..\..\Common\StringUtils.cpp" />
     <ClCompile Include="..\..\Common\System\Display.cpp" />
+    <ClCompile Include="..\..\Common\System\Request.cpp" />
     <ClCompile Include="..\..\Common\Thread\ThreadUtil.cpp" />
     <ClCompile Include="..\..\Common\Thread\ThreadManager.cpp" />
     <ClCompile Include="..\..\Common\Thread\ParallelLoop.cpp" />
diff --git a/UWP/CommonUWP/CommonUWP.vcxproj.filters b/UWP/CommonUWP/CommonUWP.vcxproj.filters
index 03f9424dfe..67e141a43f 100644
--- a/UWP/CommonUWP/CommonUWP.vcxproj.filters
+++ b/UWP/CommonUWP/CommonUWP.vcxproj.filters
@@ -429,6 +429,9 @@
     <ClCompile Include="..\..\ext\basis_universal\basisu_transcoder.cpp">
       <Filter>ext\basis_universal</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\Common\System\Request.cpp">
+      <Filter>System</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="targetver.h" />
@@ -811,6 +814,9 @@
     <ClInclude Include="..\..\ext\basis_universal\basisu_transcoder_uastc.h">
       <Filter>ext\basis_universal</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\Common\System\Request.h">
+      <Filter>System</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\..\Common\Math\fast\fast_matrix_neon.S">
diff --git a/UWP/PPSSPP_UWPMain.cpp b/UWP/PPSSPP_UWPMain.cpp
index 1529a18887..39e27cbf56 100644
--- a/UWP/PPSSPP_UWPMain.cpp
+++ b/UWP/PPSSPP_UWPMain.cpp
@@ -443,6 +443,8 @@ void System_Notify(SystemNotification notification) {
 	}
 }
 
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) { return false; }
+
 void System_SendMessage(const char *command, const char *parameter) {
 	using namespace concurrency;
 
diff --git a/Windows/MainWindow.cpp b/Windows/MainWindow.cpp
index f02d1e4f79..d81d20b121 100644
--- a/Windows/MainWindow.cpp
+++ b/Windows/MainWindow.cpp
@@ -107,7 +107,6 @@ struct VerySleepy_AddrInfo {
 };
 
 static std::wstring windowTitle;
-extern ScreenManager *screenManager;
 
 #define TIMER_CURSORUPDATE 1
 #define TIMER_CURSORMOVEUPDATE 2
@@ -473,7 +472,6 @@ namespace MainWindow
 	}
 
 	void UpdateWindowTitle() {
-		// Seems to be fine to call now since we use a UNICODE build...
 		std::wstring title = windowTitle;
 		if (PPSSPP_ID >= 1 && GetInstancePeerCount() > 1) {
 			title.append(ConvertUTF8ToWString(StringFromFormat(" (instance: %d)", (int)PPSSPP_ID)));
diff --git a/Windows/main.cpp b/Windows/main.cpp
index 4bf24d4d34..15fd6891d0 100644
--- a/Windows/main.cpp
+++ b/Windows/main.cpp
@@ -34,6 +34,7 @@
 #include "Common/System/Display.h"
 #include "Common/System/NativeApp.h"
 #include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/File/FileUtil.h"
 #include "Common/File/VFS/VFS.h"
 #include "Common/File/VFS/DirectoryReader.h"
@@ -109,8 +110,8 @@ static std::string restartArgs;
 
 int g_activeWindow = 0;
 
-static std::thread inputBoxThread;
-static bool inputBoxRunning = false;
+static std::thread g_inputBoxThread;
+static bool g_inputBoxRunning = false;
 int g_lastNumInstances = 0;
 
 void System_ShowFileInFolder(const char *path) {
@@ -376,12 +377,13 @@ static BOOL PostDialogMessage(Dialog *dialog, UINT message, WPARAM wParam = 0, L
 	return PostMessage(dialog->GetDlgHandle(), message, wParam, lParam);
 }
 
+// This can come from any thread, so this mostly uses PostMessage. Can't access most data directly.
 void System_Notify(SystemNotification notification) {
 	switch (notification) {
 	case SystemNotification::BOOT_DONE:
 	{
 		if (g_symbolMap)
-			g_symbolMap->SortSymbols();
+			g_symbolMap->SortSymbols();  // internal locking is performed here
 		PostMessage(MainWindow::GetHWND(), WM_USER + 1, 0, 0);
 
 		if (disasmWindow)
@@ -413,7 +415,7 @@ void System_Notify(SystemNotification notification) {
 
 	case SystemNotification::SYMBOL_MAP_UPDATED:
 		if (g_symbolMap)
-			g_symbolMap->SortSymbols();
+			g_symbolMap->SortSymbols();  // internal locking is performed here
 		PostMessage(MainWindow::GetHWND(), WM_USER + 1, 0, 0);
 		break;
 
@@ -428,6 +430,28 @@ void System_Notify(SystemNotification notification) {
 	}
 }
 
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) {
+	switch (type) {
+	case SystemRequestType::INPUT_TEXT_MODAL:
+		if (g_inputBoxRunning) {
+			g_inputBoxThread.join();
+		}
+
+		g_inputBoxRunning = true;
+		g_inputBoxThread = std::thread([=] {
+			std::string out;
+			if (InputBox_GetString(MainWindow::GetHInstance(), MainWindow::GetHWND(), ConvertUTF8ToWString(param1).c_str(), param2, out)) {
+				g_requestManager.PostSystemSuccess(requestId, out.c_str());
+			} else {
+				g_requestManager.PostSystemFailure(requestId);
+			}
+			});
+		return true;
+	default:
+		return false;
+	}
+}
+
 void System_SendMessage(const char *command, const char *parameter) {
 	if (!strcmp(command, "finish")) {
 		if (!NativeIsRestarting()) {
@@ -497,22 +521,6 @@ void EnableCrashingOnCrashes() {
 	FreeLibrary(kernel32);
 }
 
-void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, std::function<void(bool, const std::string &)> cb) {
-	if (inputBoxRunning) {
-		inputBoxThread.join();
-	}
-
-	inputBoxRunning = true;
-	inputBoxThread = std::thread([=] {
-		std::string out;
-		if (InputBox_GetString(MainWindow::GetHInstance(), MainWindow::GetHWND(), ConvertUTF8ToWString(title).c_str(), defaultValue, out)) {
-			NativeInputBoxReceived(cb, true, out);
-		} else {
-			NativeInputBoxReceived(cb, false, "");
-		}
-	});
-}
-
 void System_Toast(const char *text) {
 	// Not-very-good implementation. Will normally not be used on Windows anyway.
 	std::wstring str = ConvertUTF8ToWString(text);
@@ -619,9 +627,9 @@ static void WinMainInit() {
 }
 
 static void WinMainCleanup() {
-	if (inputBoxRunning) {
-		inputBoxThread.join();
-		inputBoxRunning = false;
+	if (g_inputBoxRunning) {
+		g_inputBoxThread.join();
+		g_inputBoxRunning = false;
 	}
 	net::Shutdown();
 	CoUninitialize();
diff --git a/android/jni/Android.mk b/android/jni/Android.mk
index 61aaefc181..28775b9b2f 100644
--- a/android/jni/Android.mk
+++ b/android/jni/Android.mk
@@ -214,6 +214,7 @@ EXEC_AND_LIB_FILES := \
   $(SRC)/Common/Net/WebsocketServer.cpp \
   $(SRC)/Common/Profiler/Profiler.cpp \
   $(SRC)/Common/System/Display.cpp \
+  $(SRC)/Common/System/Request.cpp \
   $(SRC)/Common/Thread/ThreadUtil.cpp \
   $(SRC)/Common/Thread/ThreadManager.cpp \
   $(SRC)/Common/Thread/ParallelLoop.cpp \
diff --git a/android/jni/app-android.cpp b/android/jni/app-android.cpp
index 65a483e519..6a9e42a829 100644
--- a/android/jni/app-android.cpp
+++ b/android/jni/app-android.cpp
@@ -61,6 +61,7 @@ struct JNIEnv {};
 #include "Common/System/Display.h"
 #include "Common/System/NativeApp.h"
 #include "Common/System/System.h"
+#include "Common/System/Request.h"
 #include "Common/Thread/ThreadUtil.h"
 #include "Common/File/Path.h"
 #include "Common/File/DirListing.h"
@@ -175,9 +176,6 @@ static std::atomic<bool> renderLoopRunning;
 static bool renderer_inited = false;
 static std::mutex renderLock;
 
-static int inputBoxSequence = 1;
-static std::map<int, std::function<void(bool, const std::string &)>> inputBoxCallbacks;
-
 static bool sustainedPerfSupported = false;
 
 static std::map<SystemPermission, PermissionStatus> permissions;
@@ -909,7 +907,6 @@ extern "C" void Java_org_ppsspp_ppsspp_NativeApp_shutdown(JNIEnv *, jclass) {
 
 	{
 		std::lock_guard<std::mutex> guard(renderLock);
-		inputBoxCallbacks.clear();
 		NativeShutdown();
 		g_VFS.Clear();
 	}
@@ -1032,12 +1029,17 @@ extern "C" void JNICALL Java_org_ppsspp_ppsspp_NativeApp_backbufferResize(JNIEnv
 	}
 }
 
-void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, std::function<void(bool, const std::string &)> cb) {
-	int seq = inputBoxSequence++;
-	inputBoxCallbacks[seq] = cb;
-
-	std::string serialized = StringFromFormat("%d:@:%s:@:%s", seq, title.c_str(), defaultValue.c_str());
-	System_SendMessage("inputbox", serialized.c_str());
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) {
+	switch (type) {
+	case SystemRequestType::INPUT_TEXT_MODAL:
+	{
+		std::string serialized = StringFromFormat("%d:@:%s:@:%s", requestId, param1.c_str(), param2.c_str());
+		PushCommand("inputbox", serialized.c_str());
+		return true;
+	}
+	default:
+		return false;
+	}
 }
 
 extern "C" void JNICALL Java_org_ppsspp_ppsspp_NativeApp_sendInputBox(JNIEnv *env, jclass, jstring jseqID, jboolean result, jstring jvalue) {
@@ -1058,13 +1060,11 @@ extern "C" void JNICALL Java_org_ppsspp_ppsspp_NativeApp_sendInputBox(JNIEnv *en
 		return;
 	}
 
-	auto entry = inputBoxCallbacks.find(seq);
-	if (entry == inputBoxCallbacks.end()) {
-		ERROR_LOG(SYSTEM, "Did not find inputbox callback for %s, shutdown?", seqID.c_str());
-		return;
+	if (result) {
+		g_requestManager.PostSystemSuccess(seq, value.c_str());
+	} else {
+		g_requestManager.PostSystemFailure(seq);
 	}
-
-	NativeInputBoxReceived(entry->second, result, value);
 }
 
 void LockedNativeUpdateRender() {
diff --git a/headless/Headless.cpp b/headless/Headless.cpp
index 27e0508e64..8d6ae20519 100644
--- a/headless/Headless.cpp
+++ b/headless/Headless.cpp
@@ -116,6 +116,7 @@ bool System_GetPropertyBool(SystemProperty prop) {
 }
 void System_Notify(SystemNotification notification) {}
 void System_SendMessage(const char *command, const char *parameter) {}
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) { return false; }
 void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, std::function<void(bool, const std::string &)> cb) { cb(false, ""); }
 void System_AskForPermission(SystemPermission permission) {}
 PermissionStatus System_GetPermissionStatus(SystemPermission permission) { return PERMISSION_STATUS_GRANTED; }
diff --git a/ios/main.mm b/ios/main.mm
index 155bf79995..3caaf93e26 100644
--- a/ios/main.mm
+++ b/ios/main.mm
@@ -219,6 +219,10 @@ void System_SendMessage(const char *command, const char *parameter) {
 	}
 }
 
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) {
+	return false;
+}
+
 void System_Toast(const char *text) {}
 void System_AskForPermission(SystemPermission permission) {}
 
diff --git a/libretro/Makefile.common b/libretro/Makefile.common
index 3beb711568..83e477f941 100644
--- a/libretro/Makefile.common
+++ b/libretro/Makefile.common
@@ -341,6 +341,7 @@ SOURCES_CXX += \
 	$(COMMONDIR)/UI/ScrollView.cpp \
 	$(COMMONDIR)/UI/PopupScreens.cpp \
 	$(COMMONDIR)/System/Display.cpp \
+	$(COMMONDIR)/System/Request.cpp \
 	$(COMMONDIR)/ArmCPUDetect.cpp \
 	$(COMMONDIR)/CPUDetect.cpp \
 	$(COMMONDIR)/Buffer.cpp \
diff --git a/libretro/libretro.cpp b/libretro/libretro.cpp
index 05b13dcdbf..cdb699bb56 100644
--- a/libretro/libretro.cpp
+++ b/libretro/libretro.cpp
@@ -1874,7 +1874,7 @@ void System_Notify(SystemNotification notification) {
       break;
    }
 }
-
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) { return false; }
 void System_SendMessage(const char *command, const char *parameter) {}
 void NativeUpdate() {}
 void NativeRender(GraphicsContext *graphicsContext) {}
diff --git a/unittest/JitHarness.cpp b/unittest/JitHarness.cpp
index ebbcdefa39..f730cc44d6 100644
--- a/unittest/JitHarness.cpp
+++ b/unittest/JitHarness.cpp
@@ -42,6 +42,7 @@ void NativeRender(GraphicsContext *graphicsContext) { }
 void NativeResized() { }
 
 void System_SendMessage(const char *command, const char *parameter) {}
+bool System_MakeRequest(SystemRequestType type, int requestId, const std::string &param1, const std::string &param2) { return false; }
 void System_InputBoxGetString(const std::string &title, const std::string &defaultValue, std::function<void(bool, const std::string &)> cb) { cb(false, ""); }
 void System_AskForPermission(SystemPermission permission) {}
 PermissionStatus System_GetPermissionStatus(SystemPermission permission) { return PERMISSION_STATUS_GRANTED; }