diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5c316d60..2e5e6bae 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -164,6 +164,7 @@ jobs:
           -DCMAKE_C_COMPILER=${{ matrix.cc }} \
           -DCMAKE_CXX_COMPILER=${{ matrix.cxx }} \
           -DCMAKE_POLICY_VERSION_MINIMUM=3.16 \
+          -DYAZE_USE_MODULAR_BUILD=ON \
           -DYAZE_MINIMAL_BUILD=ON \
           -DYAZE_ENABLE_ROM_TESTS=OFF \
           -DYAZE_ENABLE_EXPERIMENTAL_TESTS=OFF \
@@ -175,7 +176,7 @@ jobs:
       if: runner.os == 'Windows'
       shell: cmd
       run: |
-        cmake -B ${{ github.workspace }}/build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DCMAKE_POLICY_VERSION_MINIMUM=3.16 -DYAZE_MINIMAL_BUILD=ON -DYAZE_ENABLE_ROM_TESTS=OFF -DYAZE_ENABLE_EXPERIMENTAL_TESTS=OFF -DYAZE_ENABLE_UI_TESTS=OFF -Wno-dev -G "${{ matrix.cmake_generator }}" -A ${{ matrix.cmake_generator_platform }}
+        cmake -B ${{ github.workspace }}/build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DCMAKE_POLICY_VERSION_MINIMUM=3.16 -DYAZE_USE_MODULAR_BUILD=ON -DYAZE_MINIMAL_BUILD=ON -DYAZE_ENABLE_ROM_TESTS=OFF -DYAZE_ENABLE_EXPERIMENTAL_TESTS=OFF -DYAZE_ENABLE_UI_TESTS=OFF -Wno-dev -G "${{ matrix.cmake_generator }}" -A ${{ matrix.cmake_generator_platform }}
 
     # Build
     - name: Build
@@ -353,6 +354,7 @@ jobs:
           -DCMAKE_CXX_FLAGS="-fsanitize=address -fno-omit-frame-pointer" \
           -DCMAKE_C_FLAGS="-fsanitize=address -fno-omit-frame-pointer" \
           -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=address" \
+          -DYAZE_USE_MODULAR_BUILD=ON \
           -DYAZE_MINIMAL_BUILD=ON \
           -DYAZE_ENABLE_ROM_TESTS=OFF \
           -DYAZE_ENABLE_EXPERIMENTAL_TESTS=OFF \
@@ -397,6 +399,7 @@ jobs:
       run: |
         cmake -B ${{ github.workspace }}/build \
           -DCMAKE_BUILD_TYPE=Debug \
+          -DYAZE_USE_MODULAR_BUILD=ON \
           -DCMAKE_CXX_FLAGS="--coverage" \
           -DCMAKE_C_FLAGS="--coverage" \
           -DCMAKE_EXE_LINKER_FLAGS="--coverage" \
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 548e6100..057f575c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -248,6 +248,7 @@ jobs:
             -GNinja \
             -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} \
             -DCMAKE_POLICY_VERSION_MINIMUM=3.16 \
+            -DYAZE_USE_MODULAR_BUILD=ON \
             -DYAZE_BUILD_TESTS=ON \
             -DYAZE_BUILD_EMU=OFF \
             -DYAZE_BUILD_Z3ED=ON \
@@ -267,6 +268,7 @@ jobs:
             -GNinja \
             -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} \
             -DCMAKE_POLICY_VERSION_MINIMUM=3.16 \
+            -DYAZE_USE_MODULAR_BUILD=ON \
             -DYAZE_BUILD_TESTS=ON \
             -DYAZE_BUILD_EMU=OFF \
             -DYAZE_BUILD_Z3ED=ON \
@@ -296,6 +298,7 @@ jobs:
             '-A','${{ matrix.cmake_generator_platform }}',
             '-DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }}',
             '-DCMAKE_POLICY_VERSION_MINIMUM=3.16',
+            '-DYAZE_USE_MODULAR_BUILD=ON',
             '-DYAZE_BUILD_TESTS=ON',
             '-DYAZE_BUILD_EMU=OFF',
             '-DYAZE_BUILD_Z3ED=ON',
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 76fa7d11..3bb63222 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -54,6 +54,7 @@ option(YAZE_ENABLE_ROM_TESTS "Enable tests that require ROM files" OFF)
 option(YAZE_ENABLE_EXPERIMENTAL_TESTS "Enable experimental/unstable tests" ON)
 option(YAZE_ENABLE_UI_TESTS "Enable ImGui Test Engine UI testing" ON)
 option(YAZE_MINIMAL_BUILD "Minimal build for CI (disable optional features)" OFF)
+option(YAZE_USE_MODULAR_BUILD "Use modularized library build system for faster builds" OFF)
 
 # Optional JSON support (required for Gemini and structured agent responses)
 option(YAZE_WITH_JSON "Enable JSON support for AI integrations" OFF)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index efcc32db..5b104b49 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -87,6 +87,32 @@ if(YAZE_BUILD_APP OR YAZE_BUILD_Z3ED)
   include(cli/agent.cmake)
 endif()
 
+if(YAZE_USE_MODULAR_BUILD)
+  message(STATUS "Using modular build system")
+
+  if(YAZE_BUILD_LIB OR YAZE_BUILD_APP OR YAZE_BUILD_Z3ED)
+    include(app/gfx/gfx.cmake)
+    include(app/gui/gui.cmake)
+    include(app/zelda3/zelda3.cmake)
+    include(app/core/core.cmake)
+    include(app/editor/editor.cmake)
+
+    include(util/util.cmake)
+    include(app/gfx/gfx_library.cmake)
+    include(app/gui/gui_library.cmake)
+    include(app/zelda3/zelda3_library.cmake)
+
+    if(YAZE_BUILD_EMU AND NOT YAZE_WITH_GRPC)
+      include(app/emu/emu_library.cmake)
+    endif()
+
+    include(app/core/core_library.cmake)
+    include(app/editor/editor_library.cmake)
+  endif()
+else()
+  message(STATUS "Using traditional monolithic build system")
+endif()
+
 if (YAZE_BUILD_APP)
   include(app/app.cmake)
 endif()
@@ -165,29 +191,116 @@ endif()
 
 # Yaze Core Library (for testing and C API)
 if (YAZE_BUILD_LIB)
-  # Create core library for testing (includes editor and zelda3 components needed by tests)
-  set(YAZE_CORE_SOURCES
-    app/rom.cc
-    ${YAZE_APP_CORE_SRC}
-    ${YAZE_APP_GFX_SRC} 
-    ${YAZE_APP_EDITOR_SRC}
-    ${YAZE_APP_ZELDA3_SRC}
-    ${YAZE_APP_EMU_SRC}
-    ${YAZE_GUI_SRC}
-    ${YAZE_UTIL_SRC}
-    # cli/service/gui_automation_client.cc # Moved to yaze_c
-    cli/service/testing/test_workflow_generator.cc
-  )
-  
-  # Create full library for C API
+  # Sources shared by the C API library
   set(YAZE_C_SOURCES
     ./yaze.cc
     cli/service/gui/gui_automation_client.cc
   )
-  
-  # Create the core library (static for testing)
-  add_library(yaze_core STATIC ${YAZE_CORE_SOURCES})
-  
+
+  if(YAZE_USE_MODULAR_BUILD)
+    # Aggregate modular libraries into an interface target for backward compatibility
+    if(NOT TARGET yaze_core)
+      add_library(yaze_core INTERFACE)
+    endif()
+
+    target_include_directories(
+      yaze_core INTERFACE
+      ${CMAKE_SOURCE_DIR}/src/lib/
+      ${CMAKE_SOURCE_DIR}/src/app/
+      ${CMAKE_SOURCE_DIR}/src/lib/asar/src
+      ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar
+      ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar-dll-bindings/c
+      ${CMAKE_SOURCE_DIR}/incl/
+      ${CMAKE_SOURCE_DIR}/src/
+      ${CMAKE_SOURCE_DIR}/src/lib/imgui
+      ${CMAKE_SOURCE_DIR}/src/lib/imgui_test_engine
+      ${SDL2_INCLUDE_DIR}
+      ${PROJECT_BINARY_DIR}
+    )
+
+    target_link_libraries(
+      yaze_core INTERFACE
+      yaze_util
+      yaze_gfx
+      yaze_gui
+      yaze_zelda3
+      yaze_core_lib
+      yaze_editor
+      ImGui
+    )
+
+    if(TARGET yaze_agent)
+      target_link_libraries(yaze_core INTERFACE yaze_agent)
+    endif()
+
+    if(YAZE_BUILD_EMU AND NOT YAZE_WITH_GRPC AND TARGET yaze_emulator)
+      target_link_libraries(yaze_core INTERFACE yaze_emulator)
+    endif()
+
+    if(YAZE_ENABLE_UI_TESTS AND TARGET ImGuiTestEngine)
+      target_link_libraries(yaze_core INTERFACE ImGuiTestEngine)
+    endif()
+
+    if(YAZE_WITH_GRPC)
+      target_link_libraries(yaze_core INTERFACE
+        grpc++
+        grpc++_reflection
+        libprotobuf)
+    endif()
+  else()
+    # Create core library for testing (includes editor and zelda3 components needed by tests)
+    set(YAZE_CORE_SOURCES
+      app/rom.cc
+      ${YAZE_APP_CORE_SRC}
+      ${YAZE_APP_GFX_SRC} 
+      ${YAZE_APP_EDITOR_SRC}
+      ${YAZE_APP_ZELDA3_SRC}
+      ${YAZE_APP_EMU_SRC}
+      ${YAZE_GUI_SRC}
+      ${YAZE_UTIL_SRC}
+      # cli/service/gui_automation_client.cc # Moved to yaze_c
+      cli/service/testing/test_workflow_generator.cc
+    )
+
+    add_library(yaze_core STATIC ${YAZE_CORE_SOURCES})
+
+    target_include_directories(
+      yaze_core PUBLIC
+      ${CMAKE_SOURCE_DIR}/src/lib/
+      ${CMAKE_SOURCE_DIR}/src/app/
+      ${CMAKE_SOURCE_DIR}/src/lib/asar/src
+      ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar
+      ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar-dll-bindings/c
+      ${CMAKE_SOURCE_DIR}/incl/
+      ${CMAKE_SOURCE_DIR}/src/
+      ${CMAKE_SOURCE_DIR}/src/lib/imgui
+      ${CMAKE_SOURCE_DIR}/src/lib/imgui_test_engine
+      ${SDL2_INCLUDE_DIR}
+      ${PROJECT_BINARY_DIR}
+      ${CMAKE_CURRENT_BINARY_DIR}
+    )
+
+    target_link_libraries(
+      yaze_core PUBLIC
+      asar-static
+      yaze_agent
+      ${ABSL_TARGETS}
+      ${SDL_TARGETS}
+      ${CMAKE_DL_LIBS}
+      ImGui
+    )
+
+    if(YAZE_WITH_GRPC)
+      target_add_protobuf(yaze_core 
+        ${CMAKE_SOURCE_DIR}/src/app/core/proto/imgui_test_harness.proto)
+
+      target_link_libraries(yaze_core PRIVATE
+        grpc++
+        grpc++_reflection
+        libprotobuf)
+    endif()
+  endif()
+
   # Create the full C API library (static for CI, shared for release)
   if(YAZE_MINIMAL_BUILD)
     add_library(yaze_c STATIC ${YAZE_C_SOURCES})
@@ -195,44 +308,6 @@ if (YAZE_BUILD_LIB)
     add_library(yaze_c SHARED ${YAZE_C_SOURCES})
   endif()
 
-  # Configure core library (for testing)
-  target_include_directories(
-    yaze_core PUBLIC
-    ${CMAKE_SOURCE_DIR}/src/lib/
-    ${CMAKE_SOURCE_DIR}/src/app/
-    ${CMAKE_SOURCE_DIR}/src/lib/asar/src
-    ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar
-    ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar-dll-bindings/c
-    ${CMAKE_SOURCE_DIR}/incl/
-    ${CMAKE_SOURCE_DIR}/src/
-    ${CMAKE_SOURCE_DIR}/src/lib/imgui
-    ${CMAKE_SOURCE_DIR}/src/lib/imgui_test_engine
-    ${SDL2_INCLUDE_DIR}
-    ${PROJECT_BINARY_DIR}
-    ${CMAKE_CURRENT_BINARY_DIR}
-  )
-
-  target_link_libraries(
-    yaze_core PUBLIC
-    asar-static
-    yaze_agent
-    ${ABSL_TARGETS}
-    ${SDL_TARGETS}
-    ${CMAKE_DL_LIBS}
-    ImGui
-  )
-
-  if(YAZE_WITH_GRPC)
-    target_add_protobuf(yaze_core 
-      ${CMAKE_SOURCE_DIR}/src/app/core/proto/imgui_test_harness.proto)
-
-    target_link_libraries(yaze_core PRIVATE
-      grpc++
-      grpc++_reflection
-      libprotobuf)
-  endif()
-
-  # Configure full C API library
   target_include_directories(
     yaze_c PUBLIC
     ${CMAKE_SOURCE_DIR}/src/lib/
@@ -246,19 +321,41 @@ if (YAZE_BUILD_LIB)
     ${SDL2_INCLUDE_DIR}
     ${PROJECT_BINARY_DIR}
   )
-  
-  # Conditionally add PNG include dirs if available
+
   if(PNG_FOUND)
     target_include_directories(yaze_c PUBLIC ${PNG_INCLUDE_DIRS})
-    target_include_directories(yaze_core PUBLIC ${PNG_INCLUDE_DIRS})
+    if(NOT YAZE_USE_MODULAR_BUILD)
+      target_include_directories(yaze_core PUBLIC ${PNG_INCLUDE_DIRS})
+    endif()
+  endif()
+
+  if(YAZE_USE_MODULAR_BUILD)
+    target_link_libraries(
+      yaze_c PRIVATE
+      yaze_util
+      yaze_gfx
+      yaze_gui
+      yaze_zelda3
+      yaze_core_lib
+      yaze_editor
+      ImGui
+    )
+
+    if(TARGET yaze_agent)
+      target_link_libraries(yaze_c PRIVATE yaze_agent)
+    endif()
+
+    if(YAZE_BUILD_EMU AND NOT YAZE_WITH_GRPC AND TARGET yaze_emulator)
+      target_link_libraries(yaze_c PRIVATE yaze_emulator)
+    endif()
+  else()
+    target_link_libraries(
+      yaze_c PRIVATE
+      yaze_core
+      ImGui
+    )
   endif()
 
-  target_link_libraries(
-    yaze_c PRIVATE
-    yaze_core
-    ImGui
-  )
-  
   if(YAZE_WITH_GRPC)
     target_add_protobuf(yaze_c 
       ${CMAKE_SOURCE_DIR}/src/app/core/proto/imgui_test_harness.proto)
@@ -269,18 +366,18 @@ if (YAZE_BUILD_LIB)
       libprotobuf)
   endif()
 
-  # Conditionally link ImGui Test Engine and set definitions
   if(YAZE_ENABLE_UI_TESTS AND TARGET ImGuiTestEngine)
     target_link_libraries(yaze_c PRIVATE ImGuiTestEngine)
     target_compile_definitions(yaze_c PRIVATE YAZE_ENABLE_IMGUI_TEST_ENGINE=1)
   else()
     target_compile_definitions(yaze_c PRIVATE YAZE_ENABLE_IMGUI_TEST_ENGINE=0)
   endif()
-  
-  # Conditionally link PNG if available
+
   if(PNG_FOUND)
     target_link_libraries(yaze_c PRIVATE ${PNG_LIBRARIES})
-    target_link_libraries(yaze_core PRIVATE ${PNG_LIBRARIES})
+    if(NOT YAZE_USE_MODULAR_BUILD)
+      target_link_libraries(yaze_core PRIVATE ${PNG_LIBRARIES})
+    endif()
   endif()
 
   if (YAZE_INSTALL_LIB)
diff --git a/src/app/app.cmake b/src/app/app.cmake
index 2f5d2e11..b87b8fdc 100644
--- a/src/app/app.cmake
+++ b/src/app/app.cmake
@@ -98,7 +98,26 @@ else()
   target_compile_definitions(yaze PRIVATE YAZE_ENABLE_NFD=0)
 endif()
 
-target_link_libraries(yaze PRIVATE yaze_core)
+if(YAZE_USE_MODULAR_BUILD)
+  target_link_libraries(yaze PRIVATE
+    yaze_util
+    yaze_gfx
+    yaze_gui
+    yaze_zelda3
+    yaze_core_lib
+    yaze_editor
+  )
+
+  if(TARGET yaze_agent)
+    target_link_libraries(yaze PRIVATE yaze_agent)
+  endif()
+
+  if(YAZE_BUILD_EMU AND NOT YAZE_WITH_GRPC AND TARGET yaze_emulator)
+    target_link_libraries(yaze PRIVATE yaze_emulator)
+  endif()
+else()
+  target_link_libraries(yaze PRIVATE yaze_core)
+endif()
 
 # Enable policy framework in main yaze target
 target_compile_definitions(yaze PRIVATE YAZE_ENABLE_POLICY_FRAMEWORK=1)
@@ -224,22 +243,24 @@ if(YAZE_WITH_GRPC)
     ${CMAKE_SOURCE_DIR}/third_party/json/include)
   target_compile_definitions(yaze PRIVATE YAZE_WITH_JSON)
   
-  # Generate C++ code from .proto using the helper function from cmake/grpc.cmake
-  target_add_protobuf(yaze 
-    ${CMAKE_SOURCE_DIR}/src/app/core/proto/imgui_test_harness.proto)
-  
-  # Add service implementation sources
-  target_sources(yaze PRIVATE
-    ${CMAKE_SOURCE_DIR}/src/app/core/service/imgui_test_harness_service.cc
-    ${CMAKE_SOURCE_DIR}/src/app/core/service/imgui_test_harness_service.h
-    ${CMAKE_SOURCE_DIR}/src/app/core/service/screenshot_utils.cc
-    ${CMAKE_SOURCE_DIR}/src/app/core/service/screenshot_utils.h
-    ${CMAKE_SOURCE_DIR}/src/app/core/service/widget_discovery_service.cc
-    ${CMAKE_SOURCE_DIR}/src/app/core/service/widget_discovery_service.h
-    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_recorder.cc
-    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_recorder.h
-    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_script_parser.cc
-    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_script_parser.h)
+  if(NOT YAZE_USE_MODULAR_BUILD)
+    # Generate C++ code from .proto using the helper function from cmake/grpc.cmake
+    target_add_protobuf(yaze 
+      ${CMAKE_SOURCE_DIR}/src/app/core/proto/imgui_test_harness.proto)
+
+    # Add service implementation sources
+    target_sources(yaze PRIVATE
+      ${CMAKE_SOURCE_DIR}/src/app/core/service/imgui_test_harness_service.cc
+      ${CMAKE_SOURCE_DIR}/src/app/core/service/imgui_test_harness_service.h
+      ${CMAKE_SOURCE_DIR}/src/app/core/service/screenshot_utils.cc
+      ${CMAKE_SOURCE_DIR}/src/app/core/service/screenshot_utils.h
+      ${CMAKE_SOURCE_DIR}/src/app/core/service/widget_discovery_service.cc
+      ${CMAKE_SOURCE_DIR}/src/app/core/service/widget_discovery_service.h
+      ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_recorder.cc
+      ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_recorder.h
+      ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_script_parser.cc
+      ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_script_parser.h)
+  endif()
   
   # Link gRPC libraries
   target_link_libraries(yaze PRIVATE
diff --git a/src/app/core/core_library.cmake b/src/app/core/core_library.cmake
new file mode 100644
index 00000000..92711dfc
--- /dev/null
+++ b/src/app/core/core_library.cmake
@@ -0,0 +1,92 @@
+# ==============================================================================
+# Yaze Core Library
+# ==============================================================================
+# This library contains core application functionality:
+# - ROM management
+# - Project management
+# - Controller/Window management
+# - Asar wrapper for assembly
+# - Platform-specific utilities (file dialogs, fonts, clipboard)
+# - Widget state capture for testing
+# - Emulator interface
+#
+# Dependencies: yaze_util, yaze_gfx, asar, SDL2
+# ==============================================================================
+
+add_library(yaze_core_lib STATIC 
+  app/rom.cc
+  ${YAZE_APP_CORE_SRC}
+)
+
+target_include_directories(yaze_core_lib PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/src/app
+  ${CMAKE_SOURCE_DIR}/src/lib
+  ${CMAKE_SOURCE_DIR}/src/lib/imgui
+  ${CMAKE_SOURCE_DIR}/src/lib/asar/src
+  ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar
+  ${CMAKE_SOURCE_DIR}/src/lib/asar/src/asar-dll-bindings/c
+  ${CMAKE_SOURCE_DIR}/incl
+  ${SDL2_INCLUDE_DIR}
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_core_lib PUBLIC
+  yaze_util
+  yaze_gfx
+  yaze_common
+  asar-static
+  ${ABSL_TARGETS}
+  ${SDL_TARGETS}
+  ${CMAKE_DL_LIBS}
+)
+
+target_sources(yaze_core_lib PRIVATE
+  ${CMAKE_SOURCE_DIR}/src/cli/service/testing/test_workflow_generator.cc
+)
+
+if(YAZE_WITH_GRPC)
+  target_add_protobuf(yaze_core_lib
+    ${CMAKE_SOURCE_DIR}/src/app/core/proto/imgui_test_harness.proto)
+
+  target_sources(yaze_core_lib PRIVATE
+    ${CMAKE_SOURCE_DIR}/src/app/core/service/imgui_test_harness_service.cc
+    ${CMAKE_SOURCE_DIR}/src/app/core/service/imgui_test_harness_service.h
+    ${CMAKE_SOURCE_DIR}/src/app/core/service/screenshot_utils.cc
+    ${CMAKE_SOURCE_DIR}/src/app/core/service/screenshot_utils.h
+    ${CMAKE_SOURCE_DIR}/src/app/core/service/widget_discovery_service.cc
+    ${CMAKE_SOURCE_DIR}/src/app/core/service/widget_discovery_service.h
+    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_recorder.cc
+    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_recorder.h
+    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_script_parser.cc
+    ${CMAKE_SOURCE_DIR}/src/app/core/testing/test_script_parser.h
+  )
+
+  target_link_libraries(yaze_core_lib PUBLIC
+    grpc++
+    grpc++_reflection
+    libprotobuf
+  )
+endif()
+
+# Platform-specific libraries
+if(APPLE)
+  target_link_libraries(yaze_core_lib PUBLIC ${COCOA_LIBRARY})
+endif()
+
+set_target_properties(yaze_core_lib PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_core_lib PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_core_lib PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_core_lib PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_core_lib library configured")
diff --git a/src/app/editor/editor_library.cmake b/src/app/editor/editor_library.cmake
new file mode 100644
index 00000000..f6c273eb
--- /dev/null
+++ b/src/app/editor/editor_library.cmake
@@ -0,0 +1,73 @@
+# ==============================================================================
+# Yaze Editor Library
+# ==============================================================================
+# This library contains all editor functionality:
+# - Editor manager and coordination
+# - Dungeon editor (room selector, object editor, renderer)
+# - Overworld editor (map, tile16, entities)
+# - Sprite editor
+# - Music editor
+# - Message editor
+# - Assembly editor
+# - Graphics/palette editors
+# - System editors (settings, commands, extensions)
+# - Testing infrastructure
+#
+# Dependencies: yaze_core_lib, yaze_gfx, yaze_gui, yaze_zelda3, ImGui
+# ==============================================================================
+
+add_library(yaze_editor STATIC ${YAZE_APP_EDITOR_SRC})
+
+target_include_directories(yaze_editor PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/src/lib
+  ${CMAKE_SOURCE_DIR}/src/lib/imgui
+  ${CMAKE_SOURCE_DIR}/src/lib/imgui_test_engine
+  ${CMAKE_SOURCE_DIR}/incl
+  ${SDL2_INCLUDE_DIR}
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_editor PUBLIC
+  yaze_core_lib
+  yaze_gfx
+  yaze_gui
+  yaze_zelda3
+  yaze_util
+  yaze_common
+  ImGui
+)
+
+# Conditionally link ImGui Test Engine
+if(YAZE_ENABLE_UI_TESTS AND TARGET ImGuiTestEngine)
+  target_link_libraries(yaze_editor PUBLIC ImGuiTestEngine)
+  target_compile_definitions(yaze_editor PRIVATE YAZE_ENABLE_IMGUI_TEST_ENGINE=1)
+else()
+  target_compile_definitions(yaze_editor PRIVATE YAZE_ENABLE_IMGUI_TEST_ENGINE=0)
+endif()
+
+# Conditionally link gRPC if enabled
+if(YAZE_WITH_GRPC)
+  target_link_libraries(yaze_editor PRIVATE
+    grpc++
+    grpc++_reflection
+    libprotobuf
+  )
+endif()
+
+set_target_properties(yaze_editor PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_editor PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_editor PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_editor PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_editor library configured")
diff --git a/src/app/editor/graphics/graphics_editor.cc b/src/app/editor/graphics/graphics_editor.cc
index 1d4dc8cb..61b47810 100644
--- a/src/app/editor/graphics/graphics_editor.cc
+++ b/src/app/editor/graphics/graphics_editor.cc
@@ -20,7 +20,7 @@
 #include "app/gui/modules/asset_browser.h"
 #include "app/gui/style.h"
 #include "app/rom.h"
-#include "gfx/performance_profiler.h"
+#include "app/gfx/performance_profiler.h"
 #include "imgui/imgui.h"
 #include "imgui/misc/cpp/imgui_stdlib.h"
 #include "imgui_memory_editor.h"
diff --git a/src/app/emu/emu_library.cmake b/src/app/emu/emu_library.cmake
new file mode 100644
index 00000000..57f15f8e
--- /dev/null
+++ b/src/app/emu/emu_library.cmake
@@ -0,0 +1,47 @@
+# ==============================================================================
+# Yaze Emulator Library
+# ==============================================================================
+# This library contains SNES emulation functionality:
+# - CPU (65C816) implementation
+# - PPU (Picture Processing Unit) for graphics
+# - APU (Audio Processing Unit) with SPC700 and DSP
+# - DMA controller
+# - Memory management
+#
+# Dependencies: yaze_util, SDL2
+# ==============================================================================
+
+add_library(yaze_emulator STATIC ${YAZE_APP_EMU_SRC})
+
+target_include_directories(yaze_emulator PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/src/app
+  ${CMAKE_SOURCE_DIR}/src/lib
+  ${CMAKE_SOURCE_DIR}/incl
+  ${SDL2_INCLUDE_DIR}
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_emulator PUBLIC
+  yaze_util
+  yaze_common
+  ${ABSL_TARGETS}
+  ${SDL_TARGETS}
+)
+
+set_target_properties(yaze_emulator PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_emulator PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_emulator PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_emulator PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_emulator library configured")
diff --git a/src/app/gfx/gfx_library.cmake b/src/app/gfx/gfx_library.cmake
new file mode 100644
index 00000000..9201215d
--- /dev/null
+++ b/src/app/gfx/gfx_library.cmake
@@ -0,0 +1,53 @@
+# ==============================================================================
+# Yaze Graphics Library
+# ==============================================================================
+# This library contains all graphics-related functionality:
+# - Bitmap manipulation
+# - SNES tile/palette handling
+# - Compression/decompression
+# - Arena memory management
+# - Atlas rendering
+# - Performance profiling
+#
+# Dependencies: yaze_util, SDL2, Abseil
+# ==============================================================================
+
+add_library(yaze_gfx STATIC ${YAZE_APP_GFX_SRC})
+
+target_include_directories(yaze_gfx PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/src/lib
+  ${CMAKE_SOURCE_DIR}/incl
+  ${SDL2_INCLUDE_DIR}
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_gfx PUBLIC
+  yaze_util
+  yaze_common
+  ${ABSL_TARGETS}
+  ${SDL_TARGETS}
+)
+
+# Conditionally add PNG support
+if(PNG_FOUND)
+  target_include_directories(yaze_gfx PUBLIC ${PNG_INCLUDE_DIRS})
+  target_link_libraries(yaze_gfx PUBLIC ${PNG_LIBRARIES})
+endif()
+
+set_target_properties(yaze_gfx PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_gfx PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_gfx PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_gfx PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_gfx library configured")
diff --git a/src/app/gui/canvas.h b/src/app/gui/canvas.h
index d7b2b277..806cd6e6 100644
--- a/src/app/gui/canvas.h
+++ b/src/app/gui/canvas.h
@@ -1,7 +1,7 @@
 #ifndef YAZE_GUI_CANVAS_H
 #define YAZE_GUI_CANVAS_H
 
-#include "gfx/tilemap.h"
+#include "app/gfx/tilemap.h"
 #define IMGUI_DEFINE_MATH_OPERATORS
 
 #include <cstdint>
diff --git a/src/app/gui/canvas/canvas_context_menu.cc b/src/app/gui/canvas/canvas_context_menu.cc
index bbbabfa7..0ce91e92 100644
--- a/src/app/gui/canvas/canvas_context_menu.cc
+++ b/src/app/gui/canvas/canvas_context_menu.cc
@@ -9,7 +9,7 @@
 #include "app/gui/enhanced_palette_editor.h"
 #include "app/gui/bpp_format_ui.h"
 #include "app/gui/icons.h"
-#include "gui/canvas/canvas_modals.h"
+#include "app/gui/canvas/canvas_modals.h"
 #include "imgui/imgui.h"
 
 namespace yaze {
diff --git a/src/app/gui/canvas/canvas_context_menu.h b/src/app/gui/canvas/canvas_context_menu.h
index 7e5dd7fc..f73156c4 100644
--- a/src/app/gui/canvas/canvas_context_menu.h
+++ b/src/app/gui/canvas/canvas_context_menu.h
@@ -9,7 +9,7 @@
 #include "app/gfx/bitmap.h"
 #include "app/gfx/snes_palette.h"
 #include "app/gui/icons.h"
-#include "gui/canvas/canvas_modals.h"
+#include "app/gui/canvas/canvas_modals.h"
 #include "canvas_usage_tracker.h"
 #include "imgui/imgui.h"
 
diff --git a/src/app/gui/canvas/canvas_modals.h b/src/app/gui/canvas/canvas_modals.h
index a28cc22a..2baf2814 100644
--- a/src/app/gui/canvas/canvas_modals.h
+++ b/src/app/gui/canvas/canvas_modals.h
@@ -7,7 +7,7 @@
 #include "app/gfx/bitmap.h"
 #include "app/gfx/snes_palette.h"
 #include "app/gfx/bpp_format_manager.h"
-#include "gui/canvas_utils.h"
+#include "app/gui/canvas_utils.h"
 #include "imgui/imgui.h"
 
 namespace yaze {
diff --git a/src/app/gui/gui_library.cmake b/src/app/gui/gui_library.cmake
new file mode 100644
index 00000000..20d7c83a
--- /dev/null
+++ b/src/app/gui/gui_library.cmake
@@ -0,0 +1,49 @@
+# ==============================================================================
+# Yaze GUI Library
+# ==============================================================================
+# This library contains all GUI-related functionality:
+# - Canvas system
+# - ImGui widgets and utilities
+# - Input handling
+# - Theme management
+# - Color utilities
+# - Background rendering
+#
+# Dependencies: yaze_gfx, yaze_util, ImGui, SDL2
+# ==============================================================================
+
+add_library(yaze_gui STATIC ${YAZE_GUI_SRC})
+
+target_include_directories(yaze_gui PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/src/lib
+  ${CMAKE_SOURCE_DIR}/src/lib/imgui
+  ${CMAKE_SOURCE_DIR}/incl
+  ${SDL2_INCLUDE_DIR}
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_gui PUBLIC
+  yaze_gfx
+  yaze_util
+  yaze_common
+  ImGui
+  ${SDL_TARGETS}
+)
+
+set_target_properties(yaze_gui PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_gui PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_gui PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_gui PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_gui library configured")
diff --git a/src/app/gui/modules/text_editor.h b/src/app/gui/modules/text_editor.h
index e26686a5..27f9344e 100644
--- a/src/app/gui/modules/text_editor.h
+++ b/src/app/gui/modules/text_editor.h
@@ -12,7 +12,7 @@
 #include <unordered_set>
 #include <vector>
 
-#include "imgui.h"
+#include "imgui/imgui.h"
 
 class TextEditor {
  public:
diff --git a/src/app/gui/style.cc b/src/app/gui/style.cc
index 088fc610..4ee7ab5d 100644
--- a/src/app/gui/style.cc
+++ b/src/app/gui/style.cc
@@ -5,9 +5,9 @@
 #include "app/core/platform/file_dialog.h"
 #include "app/gui/theme_manager.h"
 #include "app/gui/background_renderer.h"
-#include "core/platform/font_loader.h"
-#include "gui/color.h"
-#include "gui/icons.h"
+#include "app/core/platform/font_loader.h"
+#include "app/gui/color.h"
+#include "app/gui/icons.h"
 #include "imgui/imgui.h"
 #include "imgui/imgui_internal.h"
 #include "util/log.h"
diff --git a/src/app/zelda3/zelda3_library.cmake b/src/app/zelda3/zelda3_library.cmake
new file mode 100644
index 00000000..b0f64aa3
--- /dev/null
+++ b/src/app/zelda3/zelda3_library.cmake
@@ -0,0 +1,45 @@
+# ==============================================================================
+# Yaze Zelda3 Library
+# ==============================================================================
+# This library contains all Zelda3-specific game logic:
+# - Overworld system (maps, tiles, sprites)
+# - Dungeon system (rooms, objects, sprites)
+# - Screen modules (title, inventory, dungeon map)
+# - Sprite management
+# - Music/tracker system
+#
+# Dependencies: yaze_gfx, yaze_util
+# ==============================================================================
+
+add_library(yaze_zelda3 STATIC ${YAZE_APP_ZELDA3_SRC})
+
+target_include_directories(yaze_zelda3 PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/src/lib
+  ${CMAKE_SOURCE_DIR}/incl
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_zelda3 PUBLIC
+  yaze_gfx
+  yaze_util
+  yaze_common
+  ${ABSL_TARGETS}
+)
+
+set_target_properties(yaze_zelda3 PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_zelda3 PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_zelda3 PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_zelda3 PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_zelda3 library configured")
diff --git a/src/cli/agent.cmake b/src/cli/agent.cmake
index e3a77cfd..4915f4e8 100644
--- a/src/cli/agent.cmake
+++ b/src/cli/agent.cmake
@@ -1,3 +1,69 @@
+include(FetchContent)
+
+function(_yaze_ensure_yaml_cpp _out_target)
+  if(TARGET yaml-cpp::yaml-cpp)
+    set(${_out_target} yaml-cpp::yaml-cpp PARENT_SCOPE)
+    return()
+  endif()
+
+  if(TARGET yaml-cpp)
+    set(${_out_target} yaml-cpp PARENT_SCOPE)
+    return()
+  endif()
+
+  find_package(yaml-cpp CONFIG QUIET)
+
+  if(TARGET yaml-cpp::yaml-cpp)
+    set(${_out_target} yaml-cpp::yaml-cpp PARENT_SCOPE)
+    return()
+  elseif(TARGET yaml-cpp)
+    set(${_out_target} yaml-cpp PARENT_SCOPE)
+    return()
+  endif()
+
+  message(STATUS "yaml-cpp not found via package config, fetching from source")
+
+  FetchContent_Declare(yaml-cpp
+    GIT_REPOSITORY https://github.com/jbeder/yaml-cpp.git
+    GIT_TAG 0.8.0
+  )
+
+  FetchContent_GetProperties(yaml-cpp)
+  if(NOT yaml-cpp_POPULATED)
+    FetchContent_Populate(yaml-cpp)
+
+    set(_yaml_cpp_cmakelists "${yaml-cpp_SOURCE_DIR}/CMakeLists.txt")
+    if(EXISTS "${_yaml_cpp_cmakelists}")
+      file(READ "${_yaml_cpp_cmakelists}" _yaml_cpp_cmake_contents)
+      if(_yaml_cpp_cmake_contents MATCHES "cmake_minimum_required\\(VERSION 3\\.4\\)")
+        string(REPLACE "cmake_minimum_required(VERSION 3.4)"
+                       "cmake_minimum_required(VERSION 3.5)"
+                       _yaml_cpp_cmake_contents "${_yaml_cpp_cmake_contents}")
+        file(WRITE "${_yaml_cpp_cmakelists}" "${_yaml_cpp_cmake_contents}")
+      endif()
+    endif()
+
+  set(YAML_CPP_BUILD_TESTS OFF CACHE BOOL "Disable yaml-cpp tests" FORCE)
+  set(YAML_CPP_BUILD_CONTRIB OFF CACHE BOOL "Disable yaml-cpp contrib" FORCE)
+  set(YAML_CPP_BUILD_TOOLS OFF CACHE BOOL "Disable yaml-cpp tools" FORCE)
+  set(YAML_CPP_INSTALL OFF CACHE BOOL "Disable yaml-cpp install" FORCE)
+  set(YAML_CPP_FORMAT_SOURCE OFF CACHE BOOL "Disable yaml-cpp format target" FORCE)
+
+  add_subdirectory(${yaml-cpp_SOURCE_DIR} ${yaml-cpp_BINARY_DIR} EXCLUDE_FROM_ALL)
+
+    if(NOT TARGET yaml-cpp)
+      message(FATAL_ERROR "yaml-cpp target was not created after fetching")
+    endif()
+
+    # Ensure the fetched target exposes its public headers
+    target_include_directories(yaml-cpp PUBLIC ${yaml-cpp_SOURCE_DIR}/include)
+  endif()
+
+  set(${_out_target} yaml-cpp PARENT_SCOPE)
+endfunction()
+
+_yaze_ensure_yaml_cpp(YAZE_YAML_CPP_TARGET)
+
 set(YAZE_AGENT_SOURCES
   cli/handlers/agent/tool_commands.cc
   cli/service/agent/conversational_agent_service.cc
@@ -20,13 +86,14 @@ endif()
 
 add_library(yaze_agent STATIC ${YAZE_AGENT_SOURCES})
 
-target_link_libraries(yaze_agent
-  PUBLIC
-    yaze_common
-    ${ABSL_TARGETS}
-    yaml-cpp
+set(_yaze_agent_link_targets
+  yaze_common
+  ${ABSL_TARGETS}
+  ${YAZE_YAML_CPP_TARGET}
 )
 
+target_link_libraries(yaze_agent PUBLIC ${_yaze_agent_link_targets})
+
 target_include_directories(yaze_agent
   PUBLIC
     ${CMAKE_SOURCE_DIR}/src
@@ -36,6 +103,13 @@ target_include_directories(yaze_agent
     ${CMAKE_SOURCE_DIR}/src/lib
 )
 
+if(YAZE_YAML_CPP_TARGET)
+  get_target_property(_yaze_yaml_include_dirs ${YAZE_YAML_CPP_TARGET} INTERFACE_INCLUDE_DIRECTORIES)
+  if(_yaze_yaml_include_dirs)
+    target_include_directories(yaze_agent PUBLIC ${_yaze_yaml_include_dirs})
+  endif()
+endif()
+
 if(SDL2_INCLUDE_DIR)
   target_include_directories(yaze_agent PUBLIC ${SDL2_INCLUDE_DIR})
 endif()
diff --git a/src/cli/z3ed.cmake b/src/cli/z3ed.cmake
index 151c1b2e..ce7a53d0 100644
--- a/src/cli/z3ed.cmake
+++ b/src/cli/z3ed.cmake
@@ -118,15 +118,31 @@ target_include_directories(
   ${PROJECT_BINARY_DIR}
 )
 
-target_link_libraries(
-  z3ed PRIVATE
-  yaze_core
-  ftxui::component
-  ftxui::screen
-  ftxui::dom
-  absl::flags
-  absl::flags_parse
-)
+if(YAZE_USE_MODULAR_BUILD)
+  target_link_libraries(
+    z3ed PRIVATE
+    yaze_util
+    yaze_gfx
+    yaze_zelda3
+    yaze_core_lib
+    yaze_agent
+    ftxui::component
+    ftxui::screen
+    ftxui::dom
+    absl::flags
+    absl::flags_parse
+  )
+else()
+  target_link_libraries(
+    z3ed PRIVATE
+    yaze_core
+    ftxui::component
+    ftxui::screen
+    ftxui::dom
+    absl::flags
+    absl::flags_parse
+  )
+endif()
 
 # ============================================================================
 # Optional gRPC Support for CLI Agent Test Command
diff --git a/src/util/util.cmake b/src/util/util.cmake
new file mode 100644
index 00000000..9810b416
--- /dev/null
+++ b/src/util/util.cmake
@@ -0,0 +1,47 @@
+# ==============================================================================
+# Yaze Utility Library
+# ==============================================================================
+# This library contains low-level utilities used throughout the codebase:
+# - BPS patch handling
+# - Command-line flag parsing  
+# - Hexadecimal utilities
+#
+# This library has no dependencies on GUI, graphics, or game-specific code,
+# making it the foundation of the dependency hierarchy.
+# ==============================================================================
+
+set(YAZE_UTIL_SRC
+  util/bps.cc
+  util/flag.cc
+  util/hex.cc
+)
+
+add_library(yaze_util STATIC ${YAZE_UTIL_SRC})
+
+target_include_directories(yaze_util PUBLIC
+  ${CMAKE_SOURCE_DIR}/src
+  ${CMAKE_SOURCE_DIR}/incl
+  ${PROJECT_BINARY_DIR}
+)
+
+target_link_libraries(yaze_util PUBLIC
+  yaze_common
+  ${ABSL_TARGETS}
+)
+
+set_target_properties(yaze_util PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+)
+
+# Platform-specific compile definitions
+if(UNIX AND NOT APPLE)
+  target_compile_definitions(yaze_util PRIVATE linux stricmp=strcasecmp)
+elseif(APPLE)
+  target_compile_definitions(yaze_util PRIVATE MACOS)
+elseif(WIN32)
+  target_compile_definitions(yaze_util PRIVATE WINDOWS)
+endif()
+
+message(STATUS "✓ yaze_util library configured")
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index cfe46cf5..1ea4215b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -253,7 +253,26 @@ endif()
 
   # Link core library for essential functionality (BPS, ASAR, etc.)
   if(YAZE_BUILD_LIB)
-    target_link_libraries(yaze_test yaze_core)
+    if(YAZE_USE_MODULAR_BUILD)
+      target_link_libraries(yaze_test
+        yaze_util
+        yaze_gfx
+        yaze_gui
+        yaze_zelda3
+        yaze_core_lib
+        yaze_editor
+      )
+
+      if(TARGET yaze_agent)
+        target_link_libraries(yaze_test yaze_agent)
+      endif()
+
+      if(YAZE_BUILD_EMU AND NOT YAZE_WITH_GRPC AND TARGET yaze_emulator)
+        target_link_libraries(yaze_test yaze_emulator)
+      endif()
+    else()
+      target_link_libraries(yaze_test yaze_core)
+    endif()
   endif()
 
   # Conditionally link ImGuiTestEngine only when UI tests are enabled