diff --git a/core/CMakeLists.txt b/core/CMakeLists.txt
index 3b53175..5556c7e 100644
--- a/core/CMakeLists.txt
+++ b/core/CMakeLists.txt
@@ -14,6 +14,32 @@ endif()
 
 message(STATUS "Using KiCad source at: ${KICAD_SOURCE}")
 
+# =============================================================================
+# wxWidgets Base (pre-built for WASM)
+# =============================================================================
+set(WXWIDGETS_SOURCE "${CMAKE_SOURCE_DIR}/../wxwidgets" CACHE PATH "Path to wxWidgets source")
+set(WXWIDGETS_BUILD "${CMAKE_SOURCE_DIR}/../build-wasm/wxwidgets" CACHE PATH "Path to wxWidgets WASM build")
+
+# Verify wxWidgets build exists
+if(NOT EXISTS "${WXWIDGETS_BUILD}/lib/libwx_baseu-3.2-Emscripten.a")
+    message(FATAL_ERROR "wxBase WASM build not found. Run scripts/build-wxbase-wasm.sh first")
+endif()
+
+# Create imported wxBase library
+add_library(wxbase STATIC IMPORTED)
+set_target_properties(wxbase PROPERTIES
+    IMPORTED_LOCATION "${WXWIDGETS_BUILD}/lib/libwx_baseu-3.2-Emscripten.a"
+)
+
+# wxWidgets include directories
+set(WX_INCLUDE_DIRS
+    "${WXWIDGETS_BUILD}/lib/wx/include/base-unicode-static-3.2"  # Platform setup.h
+    "${WXWIDGETS_SOURCE}/include"                                  # Main wx headers
+)
+
+message(STATUS "Using wxWidgets source at: ${WXWIDGETS_SOURCE}")
+message(STATUS "Using wxWidgets build at: ${WXWIDGETS_BUILD}")
+
 # =============================================================================
 # Options
 # =============================================================================
@@ -45,20 +71,24 @@ target_include_directories(rtree INTERFACE
 )
 
 # =============================================================================
-# Core utilities library (minimal version without wx_stl_compat)
+# Core utilities library (with wxBase support)
 # =============================================================================
 add_library(kicad_core_utils STATIC
     ${KICAD_SOURCE}/libs/core/base64.cpp
     ${KICAD_SOURCE}/libs/core/observable.cpp
     ${KICAD_SOURCE}/libs/core/profile.cpp
-    # Skip utf8.cpp and wx_stl_compat.cpp - they have heavy wx dependencies
+    ${KICAD_SOURCE}/libs/core/utf8.cpp
+    ${KICAD_SOURCE}/libs/core/wx_stl_compat.cpp
 )
 
 target_include_directories(kicad_core_utils PUBLIC
+    ${CMAKE_CURRENT_SOURCE_DIR}/wasm-config    # config.h for WASM build
+    ${WX_INCLUDE_DIRS}
     ${KICAD_SOURCE}/libs/core/include
-    ${CMAKE_CURRENT_SOURCE_DIR}/include  # For wx_shim.h
 )
 
+target_link_libraries(kicad_core_utils PUBLIC wxbase)
+
 # =============================================================================
 # S-expression library (parser for .kicad_pcb files)
 # =============================================================================
@@ -68,9 +98,11 @@ add_library(sexpr STATIC
 )
 
 target_include_directories(sexpr PUBLIC
-    ${CMAKE_CURRENT_SOURCE_DIR}/include    # wx_shim.h - FIRST!
+    ${CMAKE_CURRENT_SOURCE_DIR}/wasm-config    # config.h for WASM build
+    ${WX_INCLUDE_DIRS}
     ${KICAD_SOURCE}/libs/sexpr/include
     ${KICAD_SOURCE}/libs/core/include
+    ${KICAD_SOURCE}/include                    # string_utils.h, etc.
 )
 
 target_link_libraries(sexpr PUBLIC kicad_core_utils)
@@ -121,7 +153,7 @@ set(KIMATH_SRCS
 add_library(kimath STATIC ${KIMATH_SRCS})
 
 target_include_directories(kimath PUBLIC
-    ${CMAKE_CURRENT_SOURCE_DIR}/include    # wx_shim.h and wx/ stubs - FIRST!
+    ${WX_INCLUDE_DIRS}
     ${KICAD_SOURCE}/libs/kimath/include
     ${KICAD_SOURCE}/libs/core/include
     ${KICAD_SOURCE}/include                # Main KiCad includes (units, etc.)
diff --git a/core/include/config.h b/core/wasm-config/config.h
similarity index 88%
rename from core/include/config.h
rename to core/wasm-config/config.h
index d40b4e1..fdcec80 100644
--- a/core/include/config.h
+++ b/core/wasm-config/config.h
@@ -10,7 +10,7 @@
 // Platform detection for timing functions
 #if defined(_WIN32)
     // Windows uses GetSystemTimeAsFileTime
-#elif defined(__APPLE__) || defined(__linux__) || defined(__unix__)
+#elif defined(__EMSCRIPTEN__) || defined(__APPLE__) || defined(__linux__) || defined(__unix__)
     #define HAVE_CLOCK_GETTIME 1
 #else
     #define HAVE_GETTIMEOFDAY_FUNC 1
diff --git a/scripts/build-core-wasm.sh b/scripts/build-core-wasm.sh
new file mode 100755
index 0000000..8155ad4
--- /dev/null
+++ b/scripts/build-core-wasm.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+# Build KiCad core library for WebAssembly
+# This builds kimath, sexpr, and core utilities with wxBase
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+BUILD_DIR="$PROJECT_ROOT/build-wasm/core"
+CORE_SOURCE="$PROJECT_ROOT/core"
+
+echo "=== Building KiCad Core for WASM ==="
+echo "Project root: $PROJECT_ROOT"
+echo "Build dir: $BUILD_DIR"
+echo "Core source: $CORE_SOURCE"
+
+# Verify core source exists
+if [ ! -f "$CORE_SOURCE/CMakeLists.txt" ]; then
+    echo "ERROR: Core source not found at $CORE_SOURCE"
+    exit 1
+fi
+
+# Verify wxBase was built
+if [ ! -f "$PROJECT_ROOT/build-wasm/wxwidgets/lib/libwx_baseu-3.2-Emscripten.a" ]; then
+    echo "ERROR: wxBase not built. Run scripts/build-wxbase-wasm.sh first"
+    exit 1
+fi
+
+# Clean if requested (must be before mkdir to properly reset CMake cache)
+if [ "$1" = "--clean" ]; then
+    echo "Cleaning build directory..."
+    rm -rf "$BUILD_DIR"
+fi
+
+# Create build directory
+mkdir -p "$BUILD_DIR"
+cd "$BUILD_DIR"
+
+# Configure with emcmake
+echo ""
+echo "=== Configuring ==="
+emcmake cmake "$CORE_SOURCE" \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DBUILD_TESTS=OFF
+
+# Build
+echo ""
+echo "=== Building ==="
+emmake make -j$(nproc 2>/dev/null || sysctl -n hw.ncpu)
+
+echo ""
+echo "=== Build complete ==="
+ls -lh "$BUILD_DIR"/*.a 2>/dev/null || echo "Libraries built in $BUILD_DIR"