diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8bcc451e..703bd7c0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.21)
+cmake_minimum_required(VERSION 3.16.3)
 
 project(advanced-scene-switcher VERSION 1.0.0)
 set(LIB_NAME "${PROJECT_NAME}-lib")
@@ -267,22 +267,18 @@ target_sources(
 
 # --- End of section ---
 
-target_link_libraries(${PROJECT_NAME} PUBLIC ${LIB_NAME})
-
 if(BUILD_OUT_OF_TREE)
-  find_package(libobs REQUIRED)
-  find_package(obs-frontend-api REQUIRED)
   include(cmake/ObsPluginHelpers.cmake)
-  target_link_libraries(${LIB_NAME} PUBLIC OBS::libobs OBS::obs-frontend-api)
-else()
-  target_link_libraries(${LIB_NAME} PUBLIC OBS::libobs OBS::frontend-api)
 endif()
+include(cmake/AdvSSHelpers.cmake)
+setup_obs_lib_dependency(${LIB_NAME})
+setup_obs_lib_dependency(${PROJECT_NAME})
+
+target_link_libraries(${PROJECT_NAME} PUBLIC ${LIB_NAME})
 
 find_qt(COMPONENTS Widgets Core)
 target_link_libraries(${LIB_NAME} PUBLIC Qt::Core Qt::Widgets)
 
-include(cmake/AdvSSHelpers.cmake)
-
 # --- Platform-independent build settings ---
 
 target_include_directories(
diff --git a/cmake/AdvSSHelpers.cmake b/cmake/AdvSSHelpers.cmake
index c9569e16..d37c65ec 100644
--- a/cmake/AdvSSHelpers.cmake
+++ b/cmake/AdvSSHelpers.cmake
@@ -205,14 +205,50 @@ else()
 endif()
 
 # --- End of section ---
-
-function(setup_advss_plugin target)
+function(setup_obs_lib_dependency target)
   if(BUILD_OUT_OF_TREE)
-    target_link_libraries(${target} PUBLIC OBS::libobs OBS::obs-frontend-api)
+    find_package(libobs)
+    if(libobs_FOUND)
+      target_link_libraries(${target} PUBLIC OBS::libobs)
+    else()
+      if(NOT LIBOBS_LIB)
+        message(FATAL_ERROR "obs library not found - please set LIBOBS_LIB")
+      endif()
+      target_link_libraries(${target} PUBLIC ${LIBOBS_LIB})
+      if(NOT LIBOBS_INCLUDE_DIR)
+        message(
+          FATAL_ERROR "obs.hpp header not found - please set LIBOBS_INCLUDE_DIR"
+        )
+      endif()
+      target_include_directories(${target} PRIVATE ${LIBOBS_INCLUDE_DIR})
+    endif()
+    find_package(obs-frontend-api)
+    if(obs-frontend-api_FOUND)
+      target_link_libraries(${target} PUBLIC OBS::obs-frontend-api)
+    else()
+      if(NOT LIBOBS_FRONTEND_API_LIB)
+        message(
+          FATAL_ERROR
+            "libobs frontend-api library not found - please set LIBOBS_FRONTEND_API_LIB"
+        )
+      endif()
+      target_link_libraries(${target} PUBLIC ${LIBOBS_FRONTEND_API_LIB})
+      if(NOT LIBOBS_FRONTEND_INCLUDE_DIR)
+        message(
+          FATAL_ERROR
+            " obs-frontend-api.h not found - please set LIBOBS_FRONTEND_INCLUDE_DIR"
+        )
+      endif()
+      target_include_directories(${target}
+                                 PRIVATE ${LIBOBS_FRONTEND_INCLUDE_DIR})
+    endif()
   else()
     target_link_libraries(${target} PUBLIC OBS::libobs OBS::frontend-api)
   endif()
+endfunction()
 
+function(setup_advss_plugin target)
+  setup_obs_lib_dependency(${target})
   find_qt(COMPONENTS Widgets Core)
   target_link_libraries(${target} PRIVATE Qt::Core Qt::Widgets)
 
diff --git a/src/advanced-scene-switcher.cpp b/src/advanced-scene-switcher.cpp
index d9e033ec..caaeb8e6 100644
--- a/src/advanced-scene-switcher.cpp
+++ b/src/advanced-scene-switcher.cpp
@@ -629,9 +629,11 @@ static void OBSEvent(enum obs_frontend_event event, void *switcher)
 	case OBS_FRONTEND_EVENT_STREAMING_STOPPED:
 		resetLiveTime();
 		break;
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(26, 0, 0)
 	case OBS_FRONTEND_EVENT_REPLAY_BUFFER_SAVED:
 		setReplayBufferSaved();
 		break;
+#endif
 	case OBS_FRONTEND_EVENT_TRANSITION_STOPPED:
 		setTranstionEnd();
 		break;
diff --git a/src/legacy/scene-trigger.cpp b/src/legacy/scene-trigger.cpp
index 4fa6c861..5600ffea 100644
--- a/src/legacy/scene-trigger.cpp
+++ b/src/legacy/scene-trigger.cpp
@@ -185,18 +185,22 @@ void frontEndActionThread(sceneTriggerAction action, double delay)
 	case sceneTriggerAction::STOP_STREAMING:
 		obs_frontend_streaming_stop();
 		break;
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(26, 0, 0)
 	case sceneTriggerAction::START_REPLAY_BUFFER:
 		obs_frontend_replay_buffer_start();
 		break;
 	case sceneTriggerAction::STOP_REPLAY_BUFFER:
 		obs_frontend_replay_buffer_stop();
 		break;
+#endif
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(27, 0, 0)
 	case sceneTriggerAction::START_VCAM:
 		obs_frontend_start_virtualcam();
 		break;
 	case sceneTriggerAction::STOP_VCAM:
 		obs_frontend_stop_virtualcam();
 		break;
+#endif
 	default:
 		blog(LOG_WARNING, "ignoring unexpected frontend action '%d'",
 		     static_cast<int>(action));
diff --git a/src/macro-core/macro-action-recording.cpp b/src/macro-core/macro-action-recording.cpp
index b999650e..2e2d1801 100644
--- a/src/macro-core/macro-action-recording.cpp
+++ b/src/macro-core/macro-action-recording.cpp
@@ -43,9 +43,11 @@ bool MacroActionRecord::PerformAction()
 			obs_frontend_recording_pause(false);
 		}
 		break;
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(28, 0, 0)
 	case RecordAction::SPLIT:
 		obs_frontend_recording_split_file();
 		break;
+#endif
 	default:
 		break;
 	}
diff --git a/src/macro-core/macro-action-screenshot.cpp b/src/macro-core/macro-action-screenshot.cpp
index 6c3fc28e..c3af6974 100644
--- a/src/macro-core/macro-action-screenshot.cpp
+++ b/src/macro-core/macro-action-screenshot.cpp
@@ -11,6 +11,7 @@ bool MacroActionScreenshot::_registered = MacroActionFactory::Register(
 
 void MacroActionScreenshot::FrontendScreenshot()
 {
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(26, 0, 0)
 	if (_source) {
 		auto s = obs_weak_source_get_source(_source);
 		obs_frontend_take_source_screenshot(s);
@@ -18,6 +19,7 @@ void MacroActionScreenshot::FrontendScreenshot()
 	} else {
 		obs_frontend_take_screenshot();
 	}
+#endif
 }
 
 void MacroActionScreenshot::CustomScreenshot()
diff --git a/src/macro-core/macro-action-transition.cpp b/src/macro-core/macro-action-transition.cpp
index 268f1ef2..c74dfd62 100644
--- a/src/macro-core/macro-action-transition.cpp
+++ b/src/macro-core/macro-action-transition.cpp
@@ -49,8 +49,32 @@ void MacroActionTransition::SetTransitionOverride()
 	obs_source_release(scene);
 }
 
+#if (LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(27, 0, 0)) && \
+	(LIBOBS_API_VER < MAKE_SEMANTIC_VERSION(28, 0, 0))
+void obs_sceneitem_set_transition(obs_sceneitem_t *item, bool show,
+				  obs_source_t *transition)
+{
+	if (show) {
+		obs_sceneitem_set_show_transition(item, transition);
+	} else {
+		obs_sceneitem_set_hide_transition(item, transition);
+	}
+}
+
+void obs_sceneitem_set_transition_duration(obs_sceneitem_t *item, bool show,
+					   uint32_t duration_ms)
+{
+	if (show) {
+		obs_sceneitem_set_show_transition_duration(item, duration_ms);
+	} else {
+		obs_sceneitem_set_hide_transition_duration(item, duration_ms);
+	}
+}
+#endif
+
 void MacroActionTransition::SetSourceTransition(bool show)
 {
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(27, 0, 0)
 	auto transition =
 		obs_weak_source_get_source(_transition.GetTransition());
 	obs_data_t *settings = obs_source_get_settings(transition);
@@ -73,6 +97,7 @@ void MacroActionTransition::SetSourceTransition(bool show)
 	}
 
 	obs_source_release(t);
+#endif
 }
 
 bool MacroActionTransition::PerformAction()
diff --git a/src/macro-core/macro-action-virtual-cam.cpp b/src/macro-core/macro-action-virtual-cam.cpp
index 14843791..4d8b46c0 100644
--- a/src/macro-core/macro-action-virtual-cam.cpp
+++ b/src/macro-core/macro-action-virtual-cam.cpp
@@ -16,6 +16,7 @@ const static std::map<VCamAction, std::string> actionTypes = {
 
 bool MacroActionVCam::PerformAction()
 {
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(27, 0, 0)
 	switch (_action) {
 	case VCamAction::STOP:
 		if (obs_frontend_virtualcam_active()) {
@@ -30,6 +31,7 @@ bool MacroActionVCam::PerformAction()
 	default:
 		break;
 	}
+#endif
 	return true;
 }
 
diff --git a/src/macro-core/macro-condition-virtual-cam.cpp b/src/macro-core/macro-condition-virtual-cam.cpp
index a9f3f1e7..85b591a7 100644
--- a/src/macro-core/macro-condition-virtual-cam.cpp
+++ b/src/macro-core/macro-condition-virtual-cam.cpp
@@ -20,6 +20,7 @@ static std::map<VCamState, std::string> VCamStates = {
 bool MacroConditionVCam::CheckCondition()
 {
 	bool stateMatch = false;
+#if LIBOBS_API_VER >= MAKE_SEMANTIC_VERSION(27, 0, 0)
 	switch (_state) {
 	case VCamState::STOP:
 		stateMatch = !obs_frontend_virtualcam_active();
@@ -30,6 +31,7 @@ bool MacroConditionVCam::CheckCondition()
 	default:
 		break;
 	}
+#endif
 	return stateMatch;
 }
 
diff --git a/src/macro-core/macro-ref.hpp b/src/macro-core/macro-ref.hpp
index 2e1433dd..3512b067 100644
--- a/src/macro-core/macro-ref.hpp
+++ b/src/macro-core/macro-ref.hpp
@@ -1,5 +1,6 @@
 #pragma once
 #include <string>
+#include <vector>
 #include <QString>
 #include <obs-module.h>