diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml
index 333d96b..5df9f2b 100644
--- a/.github/workflows/validate.yml
+++ b/.github/workflows/validate.yml
@@ -51,7 +51,7 @@ jobs:
       - uses: actions/checkout@v4
       - name: Download mcpp
         env:
-          MCPP_VERSION: "0.0.40"
+          MCPP_VERSION: "0.0.41"
         run: |
           curl -L -fsS -o mcpp.tar.gz \
             "https://github.com/mcpp-community/mcpp/releases/download/v${MCPP_VERSION}/mcpp-${MCPP_VERSION}-linux-x86_64.tar.gz"
@@ -67,3 +67,61 @@ jobs:
           timeout 1800 bash tests/smoke_compat_imgui.sh
           timeout 1800 bash tests/smoke_compat_archive.sh
           timeout 1800 bash tests/smoke_compat_imgui_window.sh
+
+  smoke-portable:
+    name: smoke-${{ matrix.platform }}
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - platform: macos
+            os: macos-15
+            archive: mcpp-0.0.41-macosx-arm64.tar.gz
+            root: mcpp-0.0.41-macosx-arm64
+            mcpp: bin/mcpp
+            xlings: registry/bin/xlings
+          - platform: windows
+            os: windows-latest
+            archive: mcpp-0.0.41-windows-x86_64.zip
+            root: mcpp-0.0.41-windows-x86_64
+            mcpp: bin/mcpp.exe
+            xlings: registry/bin/xlings.exe
+    steps:
+      - uses: actions/checkout@v4
+      - name: Download mcpp
+        shell: bash
+        env:
+          MCPP_VERSION: "0.0.41"
+          MCPP_ARCHIVE: ${{ matrix.archive }}
+          MCPP_ROOT: ${{ matrix.root }}
+        run: |
+          curl -L -fsS -o "$MCPP_ARCHIVE" \
+            "https://github.com/mcpp-community/mcpp/releases/download/v${MCPP_VERSION}/${MCPP_ARCHIVE}"
+          case "$MCPP_ARCHIVE" in
+            *.zip)
+              powershell -NoProfile -Command "Expand-Archive -Force -Path '${MCPP_ARCHIVE}' -DestinationPath '.'"
+              ;;
+            *)
+              tar -xzf "$MCPP_ARCHIVE"
+              ;;
+          esac
+
+          root="$PWD/$MCPP_ROOT"
+          if [[ "$RUNNER_OS" == "Windows" ]]; then
+            echo "MCPP=$(cygpath -m "$root/${{ matrix.mcpp }}")" >> "$GITHUB_ENV"
+            echo "MCPP_VENDORED_XLINGS=$(cygpath -m "$root/${{ matrix.xlings }}")" >> "$GITHUB_ENV"
+            echo "$(cygpath -m "$root/bin")" >> "$GITHUB_PATH"
+          else
+            echo "MCPP=$root/${{ matrix.mcpp }}" >> "$GITHUB_ENV"
+            echo "MCPP_VENDORED_XLINGS=$root/${{ matrix.xlings }}" >> "$GITHUB_ENV"
+            echo "$root/bin" >> "$GITHUB_PATH"
+          fi
+      - name: Run portable compat smoke tests
+        shell: bash
+        env:
+          MCPP_INDEX_MIRROR: GLOBAL
+        run: |
+          "$MCPP" --version
+          bash tests/smoke_compat_portable.sh
diff --git a/pkgs/c/compat.ftxui.lua b/pkgs/c/compat.ftxui.lua
index c36e5c0..9a816bf 100644
--- a/pkgs/c/compat.ftxui.lua
+++ b/pkgs/c/compat.ftxui.lua
@@ -51,5 +51,8 @@ package = {
         },
         targets = { ["ftxui"] = { kind = "lib" } },
         deps    = { },
+        windows = {
+            cxxflags = { "-DUNICODE", "-D_UNICODE" },
+        },
     },
 }
diff --git a/pkgs/c/compat.mbedtls.lua b/pkgs/c/compat.mbedtls.lua
index e02d929..2613d61 100644
--- a/pkgs/c/compat.mbedtls.lua
+++ b/pkgs/c/compat.mbedtls.lua
@@ -47,5 +47,8 @@ package = {
         c_standard   = "c11",
         targets      = { ["mbedtls"] = { kind = "lib" } },
         deps         = { },
+        windows = {
+            ldflags = { "-lbcrypt" },
+        },
     },
 }
diff --git a/tests/smoke_compat_imgui_window.sh b/tests/smoke_compat_imgui_window.sh
index f0c7e5a..739d972 100755
--- a/tests/smoke_compat_imgui_window.sh
+++ b/tests/smoke_compat_imgui_window.sh
@@ -85,6 +85,7 @@ fi
 cat > src/main.cpp <<'EOF'
 #include <cstdio>
 
+#define GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
 #include <imgui.h>
 #include <imgui_impl_glfw.h>
diff --git a/tests/smoke_compat_portable.sh b/tests/smoke_compat_portable.sh
new file mode 100755
index 0000000..61f5288
--- /dev/null
+++ b/tests/smoke_compat_portable.sh
@@ -0,0 +1,266 @@
+#!/usr/bin/env bash
+# Cross-platform smoke tests for compat packages that should not depend on
+# Linux/X11 runtime libraries.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+MCPP_BIN="${MCPP:-}"
+if [[ -z "$MCPP_BIN" ]]; then
+    MCPP_BIN="$(command -v mcpp || true)"
+fi
+
+to_native_path() {
+    if [[ "${OS:-}" == "Windows_NT" ]] && command -v cygpath >/dev/null 2>&1; then
+        cygpath -m "$1"
+    else
+        printf '%s\n' "$1"
+    fi
+}
+
+to_posix_path() {
+    if [[ "${OS:-}" == "Windows_NT" ]] && command -v cygpath >/dev/null 2>&1; then
+        cygpath -u "$1"
+    else
+        printf '%s\n' "$1"
+    fi
+}
+
+MCPP_BIN_POSIX=""
+if [[ -n "$MCPP_BIN" ]]; then
+    MCPP_BIN_POSIX="$(to_posix_path "$MCPP_BIN")"
+fi
+if [[ -z "$MCPP_BIN_POSIX" || ! -f "$MCPP_BIN_POSIX" ]]; then
+    echo "FATAL: set MCPP=/path/to/mcpp or put mcpp on PATH" >&2
+    exit 1
+fi
+
+platform="$(uname -s)"
+if [[ "${OS:-}" == "Windows_NT" ]]; then
+    platform="Windows_NT"
+fi
+
+case "$platform" in
+    Windows_NT|Darwin)
+        TOOLCHAIN="${MCPP_INDEX_PORTABLE_TOOLCHAIN:-llvm@20.1.7}"
+        ;;
+    *)
+        TOOLCHAIN="${MCPP_INDEX_PORTABLE_TOOLCHAIN:-gcc@16.1.0}"
+        ;;
+esac
+
+TMP="$(mktemp -d)"
+if [[ "${MCPP_INDEX_KEEP_SMOKE_TMP:-0}" == "1" ]]; then
+    echo "KEEP: $TMP"
+else
+    trap 'rm -rf "$TMP"' EXIT
+fi
+
+MCPP_HOME_POSIX="$TMP/mcpp-home"
+mkdir -p "$MCPP_HOME_POSIX"
+export MCPP_HOME="$(to_native_path "$MCPP_HOME_POSIX")"
+
+INDEX_ROOT="$(to_native_path "$ROOT")"
+SMOKE_CACHE_DIR="${MCPP_INDEX_SMOKE_CACHE_DIR:-}"
+
+USER_MCPP="${MCPP_INDEX_USER_MCPP_HOME:-${HOME}/.mcpp}"
+mkdir -p "$MCPP_HOME_POSIX/registry/data/xpkgs"
+link_xpkgs() {
+    local src="$1"
+    [[ -d "$src" ]] || return 0
+    find "$src" -mindepth 1 -maxdepth 1 -type d | while read -r pkg; do
+        [[ "$(basename "$pkg")" == compat-x-* ]] && continue
+        ln -s "$pkg" "$MCPP_HOME_POSIX/registry/data/xpkgs/$(basename "$pkg")" 2>/dev/null || true
+    done
+}
+link_xpkgs "${MCPP_INDEX_SMOKE_XPKGS_DIR:-}"
+link_xpkgs "$USER_MCPP/registry/data/xpkgs"
+if [[ -d "$USER_MCPP/registry/data/xim-pkgindex" ]]; then
+    mkdir -p "$MCPP_HOME_POSIX/registry/data/xim-pkgindex"
+    cp -a "$USER_MCPP/registry/data/xim-pkgindex/." "$MCPP_HOME_POSIX/registry/data/xim-pkgindex/" 2>/dev/null || true
+    rm -f "$MCPP_HOME_POSIX/registry/data/xim-pkgindex/.xlings-index-cache.json"
+fi
+if [[ -d "$USER_MCPP/registry/bin" ]]; then
+    mkdir -p "$MCPP_HOME_POSIX/registry"
+    ln -s "$USER_MCPP/registry/bin" "$MCPP_HOME_POSIX/registry/bin" 2>/dev/null || true
+fi
+if [[ -f "$USER_MCPP/config.toml" ]]; then
+    cp -f "$USER_MCPP/config.toml" "$MCPP_HOME_POSIX/config.toml" 2>/dev/null || true
+fi
+
+"$MCPP_BIN_POSIX" self config --mirror "${MCPP_INDEX_MIRROR:-GLOBAL}"
+
+copy_smoke_cache() {
+    [[ -n "$SMOKE_CACHE_DIR" && -d "$SMOKE_CACHE_DIR" ]] || return 0
+    mkdir -p .mcpp/.xlings/data/runtimedir
+    find "$SMOKE_CACHE_DIR" -maxdepth 1 -type f \
+        \( -name '*.tar.gz' -o -name '*.tar.xz' -o -name '*.zip' \) \
+        -exec cp -f {} .mcpp/.xlings/data/runtimedir/ \;
+}
+
+write_build_ldflags() {
+    case "$platform" in
+        Linux)
+            cat <<'EOF'
+
+[build]
+ldflags = ["-ldl", "-lm"]
+EOF
+            ;;
+        Darwin)
+            cat <<'EOF'
+
+[build]
+ldflags = ["-lm"]
+EOF
+            ;;
+    esac
+}
+
+make_project() {
+    local name="$1"
+    mkdir -p "$TMP/$name/src"
+    cd "$TMP/$name"
+    cat > mcpp.toml <<EOF
+[package]
+name = "$name"
+version = "0.1.0"
+
+[toolchain]
+default = "$TOOLCHAIN"
+
+[indices]
+compat = { path = "$INDEX_ROOT" }
+
+[targets.$name]
+kind = "bin"
+main = "src/main.cpp"
+EOF
+    copy_smoke_cache
+}
+
+make_project "compat-portable-core-smoke"
+cat >> mcpp.toml <<'EOF'
+
+[dependencies.compat]
+gtest = "1.15.2"
+ftxui = "6.1.9"
+lua = "5.4.7"
+mbedtls = "3.6.1"
+opengl = "2026.05.31"
+khrplatform = "2026.05.31"
+EOF
+write_build_ldflags >> mcpp.toml
+cat > src/main.cpp <<'EOF'
+#include <array>
+#include <string>
+
+#include <GL/gl.h>
+#include <KHR/khrplatform.h>
+#include <ftxui/dom/elements.hpp>
+#include <ftxui/screen/screen.hpp>
+#include <gtest/gtest.h>
+#include <mbedtls/sha256.h>
+
+extern "C" {
+#include <lauxlib.h>
+#include <lua.h>
+#include <lualib.h>
+}
+
+TEST(CompatPortableCore, UpstreamHeadersAndRuntime) {
+    using namespace ftxui;
+    Element document = hbox({text("compat"), separator(), text("ftxui")});
+    Screen screen = Screen::Create(Dimension::Fit(document), Dimension::Fit(document));
+    Render(screen, document);
+    const std::string rendered = screen.ToString();
+    EXPECT_NE(rendered.find("compat"), std::string::npos);
+    EXPECT_NE(rendered.find("ftxui"), std::string::npos);
+
+    lua_State* state = luaL_newstate();
+    ASSERT_NE(state, nullptr);
+    luaL_openlibs(state);
+    ASSERT_EQ(luaL_dostring(state, "return 20 + 22"), LUA_OK);
+    EXPECT_TRUE(lua_isinteger(state, -1));
+    EXPECT_EQ(lua_tointeger(state, -1), 42);
+    lua_close(state);
+
+    const unsigned char input[] = "abc";
+    std::array<unsigned char, 32> out{};
+    mbedtls_sha256(input, 3, out.data(), 0);
+    EXPECT_EQ(out[0], 0xba);
+    EXPECT_EQ(out[1], 0x78);
+    EXPECT_EQ(out[30], 0x15);
+    EXPECT_EQ(out[31], 0xad);
+
+    EXPECT_EQ(GL_TEXTURE_2D, 0x0DE1);
+    EXPECT_EQ(static_cast<khronos_uint32_t>(1), 1u);
+}
+EOF
+"$MCPP_BIN_POSIX" build
+"$MCPP_BIN_POSIX" run
+
+make_project "compat-portable-archive-smoke"
+cat >> mcpp.toml <<'EOF'
+
+[dependencies.compat]
+libarchive = "3.8.7"
+EOF
+cat > src/main.cpp <<'EOF'
+#include <archive.h>
+#include <archive_entry.h>
+#include <bzlib.h>
+#include <lz4.h>
+#include <lzma.h>
+#include <zlib.h>
+#include <zstd.h>
+
+int main() {
+    archive* writer = archive_write_new();
+    if (!writer) return 1;
+    archive_write_free(writer);
+
+    archive_entry* entry = archive_entry_new();
+    if (!entry) return 2;
+    archive_entry_free(entry);
+
+    if (!archive_version_string()) return 3;
+    if (!zlibVersion()) return 4;
+    if (!BZ2_bzlibVersion()) return 5;
+    if (LZ4_versionNumber() <= 0) return 6;
+    if (ZSTD_versionNumber() == 0) return 7;
+    if (lzma_version_number() == 0) return 8;
+    return 0;
+}
+EOF
+"$MCPP_BIN_POSIX" build
+"$MCPP_BIN_POSIX" run
+
+make_project "compat-portable-imgui-glfw-smoke"
+cat >> mcpp.toml <<'EOF'
+
+[dependencies.compat]
+imgui = "1.92.8"
+glfw = "3.4"
+EOF
+cat > src/main.cpp <<'EOF'
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+#include <imgui.h>
+#include <imgui_impl_glfw.h>
+#include <imgui_impl_opengl3.h>
+
+#include "imgui_impl_glfw.cpp"
+#include "imgui_impl_opengl3.cpp"
+
+int main() {
+    const char* glfw = glfwGetVersionString();
+    const char* imgui = ImGui::GetVersion();
+    return glfw && imgui &&
+           GLFW_VERSION_MAJOR == 3 &&
+           IMGUI_VERSION_NUM >= 19200 ? 0 : 1;
+}
+EOF
+"$MCPP_BIN_POSIX" build
+"$MCPP_BIN_POSIX" run
+
+echo "OK"