diff --git a/main/CMakeLists.txt b/main/CMakeLists.txt
index 5dcea05..65597ac 100644
--- a/main/CMakeLists.txt
+++ b/main/CMakeLists.txt
@@ -1,5 +1,20 @@
 set(requires esp-tls spi_flash nvs_flash esp_event esp_netif esp_http_client esp_http_server esp_wifi esp_psram esp_lvgl_port)
-file(GLOB_RECURSE SRCS "main.cpp" "*.cpp" "*.c" "ui/**/*.cpp" "ui/**/*.c" "external/**/*.cpp" "external/**/*.c")
+
+# Start the source list with the known root source
+set(SRCS "${CMAKE_CURRENT_LIST_DIR}/main.cpp")
+# Delegate source collection to per-directory CMakeLists (non-recursive)
+set(SUBDIRS "display" "external" "ui" "io" "network" "info" "common")
+foreach(dir IN LISTS SUBDIRS)
+    if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/${dir}/CMakeLists.txt")
+        include("${CMAKE_CURRENT_LIST_DIR}/${dir}/CMakeLists.txt")
+    else()
+        file(GLOB DIR_SRCS "${CMAKE_CURRENT_LIST_DIR}/${dir}/*.c" "${CMAKE_CURRENT_LIST_DIR}/${dir}/*.cpp")
+        if(DIR_SRCS)
+            list(APPEND SRCS ${DIR_SRCS})
+        endif()
+    endif()
+endforeach()
+
 
 
 # Path to the source JSON in this component
diff --git a/main/common/CMakeLists.txt b/main/common/CMakeLists.txt
new file mode 100644
index 0000000..d8592ce
--- /dev/null
+++ b/main/common/CMakeLists.txt
@@ -0,0 +1 @@
+# common/ currently contains headers; no sources to add by default
diff --git a/main/display/CMakeLists.txt b/main/display/CMakeLists.txt
new file mode 100644
index 0000000..5f81a4d
--- /dev/null
+++ b/main/display/CMakeLists.txt
@@ -0,0 +1,5 @@
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/eink_display_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/epd_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/lvgl_handler.cpp"
+)
diff --git a/main/external/CMakeLists.txt b/main/external/CMakeLists.txt
new file mode 100644
index 0000000..a66deae
--- /dev/null
+++ b/main/external/CMakeLists.txt
@@ -0,0 +1,6 @@
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/mtr/mtr.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/mtr/station_info.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/mtr/line_info.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/mtr/arrival.cpp"
+)
diff --git a/main/info/CMakeLists.txt b/main/info/CMakeLists.txt
new file mode 100644
index 0000000..21b4a12
--- /dev/null
+++ b/main/info/CMakeLists.txt
@@ -0,0 +1,3 @@
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/info.cpp"
+)
diff --git a/main/io/CMakeLists.txt b/main/io/CMakeLists.txt
new file mode 100644
index 0000000..54c5572
--- /dev/null
+++ b/main/io/CMakeLists.txt
@@ -0,0 +1,4 @@
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/fs_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/nvs_handler.cpp"
+)
diff --git a/main/network/CMakeLists.txt b/main/network/CMakeLists.txt
new file mode 100644
index 0000000..ce2688f
--- /dev/null
+++ b/main/network/CMakeLists.txt
@@ -0,0 +1,7 @@
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/http_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/wifi_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/web_server_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/udp_client.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/network.cpp"
+)
diff --git a/main/ui/CMakeLists.txt b/main/ui/CMakeLists.txt
new file mode 100644
index 0000000..6263297
--- /dev/null
+++ b/main/ui/CMakeLists.txt
@@ -0,0 +1,14 @@
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/ui_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/root_layout.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/interaction_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/events.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/apps/registry.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/widgets/textarea.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/widgets/button.cpp"
+)
+
+# Apps control: include apps/CMakeLists.txt which selects which apps to add
+if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/apps/CMakeLists.txt")
+    include("${CMAKE_CURRENT_LIST_DIR}/apps/CMakeLists.txt")
+endif()
diff --git a/main/ui/apps/CMakeLists.txt b/main/ui/apps/CMakeLists.txt
new file mode 100644
index 0000000..d21ef19
--- /dev/null
+++ b/main/ui/apps/CMakeLists.txt
@@ -0,0 +1,19 @@
+# Control which apps are included in the build.
+# Override `ENABLED_APPS` from the top-level CMake command line to change apps.
+if(NOT DEFINED ENABLED_APPS)
+    set(ENABLED_APPS "iotdis")
+    endif()
+message(STATUS "Enabled apps: ${ENABLED_APPS}")
+
+foreach(app IN LISTS ENABLED_APPS)
+    set(APP_DIR "${CMAKE_CURRENT_LIST_DIR}/${app}")
+    if(EXISTS "${APP_DIR}/CMakeLists.txt")
+        include("${APP_DIR}/CMakeLists.txt")
+    else()
+        message(WARNING "App '${app}' has no CMakeLists.txt — attempting to add any sources directly")
+        file(GLOB APP_SRCS "${APP_DIR}/*.c" "${APP_DIR}/*.cpp" "${APP_DIR}/*/*.c" "${APP_DIR}/*/*.cpp")
+        if(APP_SRCS)
+            list(APPEND SRCS ${APP_SRCS})
+        endif()
+    endif()
+endforeach()
diff --git a/main/ui/apps/iotdis/CMakeLists.txt b/main/ui/apps/iotdis/CMakeLists.txt
new file mode 100644
index 0000000..999517c
--- /dev/null
+++ b/main/ui/apps/iotdis/CMakeLists.txt
@@ -0,0 +1,12 @@
+# Explicit list of iotdis app sources
+list(APPEND SRCS
+    "${CMAKE_CURRENT_LIST_DIR}/web/web_handlers.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/descriptor.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/settings/settings_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/app.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/bridge/bridge.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/ui/settings_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/ui/settings.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/ui/main_handler.cpp"
+    "${CMAKE_CURRENT_LIST_DIR}/ui/main.cpp"
+)