diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
new file mode 100644
index 0000000..9b2d941
--- /dev/null
+++ b/.github/workflows/build.yaml
@@ -0,0 +1,530 @@
+name: python-tests
+
+on:
+  push:
+    branches: [main, py_wheel*]
+  release:
+    types: [published]
+
+jobs:
+  newsynth:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-15-intel
+          - macos-latest
+          - windows-latest
+          - ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Restore newsynth cache
+        id: newsynth-cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            externals/bin
+            externals/newsynth-license
+          key: newsynth-${{ matrix.os }}-v1
+
+      - name: Setup Haskell (GHC/Cabal)
+        if: steps.newsynth-cache.outputs.cache-hit != 'true'
+        uses: haskell-actions/setup@v2
+        with:
+          ghc-version: "9.6.6"
+          cabal-version: "3.12.1.0"
+
+      - name: Build newsynth binaries from Hackage
+        if: steps.newsynth-cache.outputs.cache-hit != 'true'
+        run: |
+          cabal update
+          cabal install newsynth --installdir "$PWD/externals/bin" --install-method=copy --overwrite-policy=always
+          if [ "$RUNNER_OS" != "Windows" ]; then
+            chmod +x "$PWD/externals/bin/gridsynth"
+          fi
+          ls -la "$PWD/externals/bin"
+        shell: bash
+
+      - name: Download newsynth LICENSE files
+        if: steps.newsynth-cache.outputs.cache-hit != 'true'
+        run: |
+          rm -rf "$PWD/externals/newsynth-src"
+          rm -rf "$PWD/externals/newsynth-license"
+          mkdir -p "$PWD/externals/newsynth-src"
+          mkdir -p "$PWD/externals/newsynth-license"
+          cabal get newsynth --destdir "$PWD/externals/newsynth-src" --pristine
+          newsynth_src_dir=$(find "$PWD/externals/newsynth-src" -maxdepth 1 -type d -name "newsynth-*" | head -n 1)
+          if [ -n "$newsynth_src_dir" ]; then
+            find "$newsynth_src_dir" -maxdepth 2 -type f \
+              \( -iname "LICENSE*" -o -iname "COPYING*" -o -iname "README*" -o -iname "GPL*" \) \
+              -exec cp {} "$PWD/externals/newsynth-license/" \;
+          fi
+          echo "---"
+          ls -la "$PWD/externals/newsynth-src"
+          echo "---"
+          ls -la "$PWD/externals/newsynth-license"
+        shell: bash
+
+  wheel:
+    needs: [newsynth]
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-15-intel
+          - macos-latest
+          - windows-latest
+          - ubuntu-latest
+        build-target:
+          - cp310-cp310
+          - cp311-cp311
+          - cp312-abi3
+        include:
+          - build-target: cp310-cp310
+            python-version: "3.10"
+          - build-target: cp311-cp311
+            python-version: "3.11"
+          - build-target: cp312-abi3
+            python-version: "3.12"
+    continue-on-error: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: "pip"
+          cache-dependency-path: pyproject.toml
+
+      - name: Setup MSVC (Windows)
+        if: runner.os == 'Windows'
+        uses: ilammy/msvc-dev-cmd@v1
+        with:
+          arch: x64
+
+      - name: Shorten build paths (Windows)
+        if: runner.os == 'Windows'
+        run: |
+          New-Item -ItemType Directory -Force -Path C:\b | Out-Null
+          New-Item -ItemType Directory -Force -Path C:\t | Out-Null
+          Add-Content -Path $env:GITHUB_ENV -Value "SKBUILD_BUILD_DIR=C:\b"
+          Add-Content -Path $env:GITHUB_ENV -Value "TMP=C:\t"
+          Add-Content -Path $env:GITHUB_ENV -Value "TEMP=C:\t"
+        shell: pwsh
+
+      - name: Configure vcpkg toolchain
+        if: runner.os != 'Linux'
+        run: |
+          mkdir -p "${{ github.workspace }}/.vcpkg"
+          echo "VCPKG_ROOT=${{ github.workspace }}/.vcpkg" >> "$GITHUB_ENV"
+          git clone https://github.com/microsoft/vcpkg.git "${{ github.workspace }}/.vcpkg"
+          ls "${{ github.workspace }}/.vcpkg"
+
+      # - name: Install libyaml-cpp (Linux)
+      #   if: runner.os == 'Linux'
+      #   run: |
+      #     sudo apt-get update
+      #     sudo apt-get install -y build-essential gcc g++ libyaml-cpp0.8 libyaml-cpp-dev
+
+      # - name: Set compiler env (Linux)
+      #   if: runner.os == 'Linux'
+      #   run: |
+      #     echo "CC=gcc" >> "$GITHUB_ENV"
+      #     echo "CXX=g++" >> "$GITHUB_ENV"
+
+      - name: Install libyaml-cpp (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          brew install yaml-cpp
+
+      - name: Configure Homebrew lib path (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          brew_prefix=$(brew --prefix yaml-cpp)
+          if [ -n "$brew_prefix" ]; then
+            echo "DYLD_LIBRARY_PATH=$brew_prefix/lib:$DYLD_LIBRARY_PATH" >> "$GITHUB_ENV"
+          fi
+
+      - name: Set compiler env (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          echo "CC=clang" >> "$GITHUB_ENV"
+          echo "CXX=clang++" >> "$GITHUB_ENV"
+
+      - name: Restore newsynth cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            externals/bin
+            externals/newsynth-license
+          key: newsynth-${{ matrix.os }}-v1
+          fail-on-cache-miss: true
+
+      - name: Fix newsynth permissions (Unix)
+        if: runner.os != 'Windows'
+        run: chmod +x "$PWD/externals/bin/gridsynth"
+        shell: bash
+
+      - name: Build wheel with cibuildwheel (Linux)
+        if: runner.os == 'Linux'
+        uses: pypa/cibuildwheel@v2.23.0
+        env:
+          CIBW_BUILD: ${{ matrix.build-target == 'cp310-cp310' && 'cp310-manylinux_x86_64' || matrix.build-target == 'cp311-cp311' && 'cp311-manylinux_x86_64' || 'cp312-manylinux_x86_64' }}
+          CIBW_SKIP: "*-musllinux_*"
+          CIBW_MANYLINUX_X86_64_IMAGE: manylinux_2_28
+          CIBW_CONFIG_SETTINGS: ${{ matrix.build-target == 'cp312-abi3' && 'wheel.py-api=cp312' || 'wheel.py-api=' }}
+          CIBW_BEFORE_ALL_LINUX: |
+            dnf install -y git gcc gcc-c++ make zip unzip tar curl perl
+            git clone https://github.com/microsoft/vcpkg.git /project/.vcpkg
+            /project/.vcpkg/bootstrap-vcpkg.sh -disableMetrics
+          CIBW_ENVIRONMENT_LINUX: >-
+            VCPKG_ROOT=/project/.vcpkg
+            SKBUILD_CMAKE_DEFINE="CMAKE_TOOLCHAIN_FILE=/project/.vcpkg/scripts/buildsystems/vcpkg.cmake;QRET_BUILD_PYTHON=ON"
+        with:
+          package-dir: .
+          output-dir: dist
+
+      - name: Build wheel (non-Linux)
+        if: runner.os != 'Linux'
+        env:
+          SKBUILD_CMAKE_DEFINE: "CMAKE_TOOLCHAIN_FILE=${{env.VCPKG_ROOT}}/scripts/buildsystems/vcpkg.cmake;QRET_BUILD_PYTHON=ON"
+        run: |
+          python -m pip install --upgrade pip build pytest coverage wheel numpy
+          python -m build --wheel -Cwheel.py-api=${{ matrix.build-target == 'cp312-abi3' && 'cp312' || '' }}
+        shell: bash
+
+      - name: Embed newsynth binary and LICENSE files into wheel
+        run: |
+          wheel_file=$(ls dist/*.whl)
+          python -m pip install --upgrade wheel
+          python -m wheel unpack "$wheel_file" -d dist/unpacked
+          wheel_dir=$(ls -d dist/unpacked/*)
+          pkg_dir="$wheel_dir/pyqret/externals/newsynth"
+          mkdir -p "$pkg_dir"
+
+          # Copy built binaries into pyqret/externals/newsynth.
+          for file in "$PWD"/externals/bin/*; do
+            cp "$file" "$pkg_dir/"
+          done
+
+          # Copy downloaded license files.
+          find "$PWD/externals/newsynth-license" -mindepth 1 -maxdepth 1 -type f -exec cp {} "$pkg_dir/" \;
+
+          # Remove unexpected top-level lib64 directory from the wheel payload.
+          rm -rf "$wheel_dir/lib64"
+
+          rm -f "$wheel_file"
+          python -m wheel pack "$wheel_dir" -d dist
+          ls -la "$pkg_dir"
+        shell: bash
+
+      - name: Validate wheel filename and extension tags
+        run: |
+          wheel_file=$(ls dist/*.whl)
+          wheel_name=$(basename "$wheel_file")
+          echo "Built wheel: $wheel_name"
+
+          expected_tag="${{ matrix.build-target }}-"
+
+          if [[ "$wheel_name" != *"$expected_tag"* ]]; then
+            echo "Unexpected wheel ABI tag for ${{ matrix.build-target }}."
+            echo "Actual filename: $wheel_name"
+            echo "Expected filename to contain: $expected_tag"
+            exit 1
+          fi
+
+          check_dir="dist/wheel-check"
+          rm -rf "$check_dir"
+          mkdir -p "$check_dir"
+          python -m zipfile -e "$wheel_file" "$check_dir"
+
+          target_tag="${{ matrix.build-target }}"
+          py_tag="${target_tag%%-*}"
+          abi_tag="${target_tag#*-}"
+          py_major_minor="${py_tag#cp}"
+          py_major="${py_major_minor:0:1}"
+          py_minor="${py_major_minor:1}"
+          cpython_tag="cpython-${py_major}${py_minor}"
+          found_ext=0
+
+          while IFS= read -r ext_file; do
+            found_ext=1
+            ext_name=$(basename "$ext_file")
+            echo "Found extension stub: $ext_name"
+            if [[ "$ext_name" == *"$abi_tag"* || "$ext_name" == *"$py_tag"* || "$ext_name" == *"$cpython_tag"* ]]; then
+              continue
+            fi
+
+            if [[ "${{ runner.os }}" == "Windows" && "$ext_name" == *.pyd ]]; then
+              echo "Accepting untagged Windows extension stub: $ext_name"
+              continue
+            fi
+
+            echo "Extension stub tag mismatch for ${{ matrix.build-target }}: $ext_name"
+            echo "Expected extension filename to contain one of: $abi_tag, $py_tag, $cpython_tag"
+            exit 1
+          done < <(find "$check_dir" -type f \( -name "*.so" -o -name "*.dylib" -o -name "*.lib" -o -name "*.pyd" \))
+
+          if [ "$found_ext" -eq 0 ]; then
+            echo "No extension stub (*.so/*.dylib/*.lib/*.pyd) found in wheel."
+            exit 1
+          fi
+        shell: bash
+
+      - name: Upload Python artifacts
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: pyqret-wheel-${{ matrix.os }}-${{ matrix.build-target }}
+          path: |
+            dist/*.whl
+
+  sdist:
+    needs: [newsynth]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+          cache: "pip"
+          cache-dependency-path: pyproject.toml
+
+      - name: Configure vcpkg toolchain
+        run: |
+          mkdir -p "${{ github.workspace }}/.vcpkg"
+          echo "VCPKG_ROOT=${{ github.workspace }}/.vcpkg" >> "$GITHUB_ENV"
+          git clone https://github.com/microsoft/vcpkg.git "${{ github.workspace }}/.vcpkg"
+          ls "${{ github.workspace }}/.vcpkg"
+
+      - name: Install libyaml-cpp (Linux)
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential gcc g++ libyaml-cpp0.8 libyaml-cpp-dev
+
+      - name: Set compiler env (Linux)
+        run: |
+          echo "CC=gcc" >> "$GITHUB_ENV"
+          echo "CXX=g++" >> "$GITHUB_ENV"
+
+      - name: Restore newsynth cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            externals/bin
+            externals/newsynth-license
+          key: newsynth-ubuntu-latest-v1
+          fail-on-cache-miss: true
+
+      - name: Set newsynth permissions
+        run: |
+          chmod +x "$PWD/externals/bin/gridsynth"
+          ls -la "$PWD/externals/bin"
+        shell: bash
+
+      - name: Build sdist
+        run: |
+          python -m pip install --upgrade pip build pytest coverage numpy
+          python -m build --sdist
+        shell: bash
+
+      - name: Upload sdist artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: pyqret-sdist
+          path: |
+            dist/*.tar.gz
+
+  test-wheel:
+    needs: [wheel]
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-15-intel
+          - macos-latest
+          - windows-latest
+          - ubuntu-latest
+        python-version:
+          - "3.10"
+          - "3.11"
+          - "3.12"
+          - "3.13"
+          - "3.14"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: "pip"
+          cache-dependency-path: pyproject.toml
+
+      - name: Download wheel artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: pyqret-wheel-${{ matrix.os }}-${{ matrix.python-version == '3.10' && 'cp310-cp310' || matrix.python-version == '3.11' && 'cp311-cp311' || 'cp312-abi3' }}
+          path: dist
+
+      - name: Install wheel
+        run: |
+          python -m pip install --upgrade pip pytest coverage numpy
+          python -m pip install dist/*.whl
+        shell: bash
+
+      - name: test gridsynth bundle
+        run: python -c "import pyqret; import os; import subprocess; subprocess.run([os.environ['GRIDSYNTH_PATH'], '--help'], check=True)"
+
+      - name: Run tests
+        run: python -m pytest quration-core/python/tests
+        shell: bash
+
+  test-sdist:
+    needs: [sdist]
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-15-intel
+          - macos-latest
+          - windows-latest
+          - ubuntu-latest
+        python-version:
+          - "3.10"
+          #- "3.11"
+          #- "3.12"
+          #- "3.13"
+          - "3.14"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: "pip"
+          cache-dependency-path: pyproject.toml
+
+      - name: Setup MSVC (Windows)
+        if: runner.os == 'Windows'
+        uses: ilammy/msvc-dev-cmd@v1
+        with:
+          arch: x64
+
+      - name: Shorten build paths (Windows)
+        if: runner.os == 'Windows'
+        run: |
+          New-Item -ItemType Directory -Force -Path C:\b | Out-Null
+          New-Item -ItemType Directory -Force -Path C:\t | Out-Null
+          Add-Content -Path $env:GITHUB_ENV -Value "SKBUILD_BUILD_DIR=C:\b"
+          Add-Content -Path $env:GITHUB_ENV -Value "TMP=C:\t"
+          Add-Content -Path $env:GITHUB_ENV -Value "TEMP=C:\t"
+        shell: pwsh
+
+      - name: Configure vcpkg toolchain
+        run: |
+          mkdir -p "${{ github.workspace }}/.vcpkg"
+          echo "VCPKG_ROOT=${{ github.workspace }}/.vcpkg" >> "$GITHUB_ENV"
+          git clone https://github.com/microsoft/vcpkg.git "${{ github.workspace }}/.vcpkg"
+          ls "${{ github.workspace }}/.vcpkg"
+
+      - name: Install libyaml-cpp (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential gcc g++ libyaml-cpp0.8 libyaml-cpp-dev
+
+      - name: Set compiler env (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          echo "CC=gcc" >> "$GITHUB_ENV"
+          echo "CXX=g++" >> "$GITHUB_ENV"
+
+      - name: Install libyaml-cpp (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          brew install yaml-cpp
+
+      - name: Configure Homebrew lib path (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          brew_prefix=$(brew --prefix yaml-cpp)
+          if [ -n "$brew_prefix" ]; then
+            echo "DYLD_LIBRARY_PATH=$brew_prefix/lib:$DYLD_LIBRARY_PATH" >> "$GITHUB_ENV"
+          fi
+
+      - name: Set compiler env (macOS)
+        if: runner.os == 'macOS'
+        run: |
+          echo "CC=clang" >> "$GITHUB_ENV"
+          echo "CXX=clang++" >> "$GITHUB_ENV"
+
+      - name: Download sdist artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: pyqret-sdist
+          path: dist
+
+      - name: Install sdist
+        env:
+          SKBUILD_CMAKE_DEFINE: "CMAKE_TOOLCHAIN_FILE=${{env.VCPKG_ROOT}}/scripts/buildsystems/vcpkg.cmake;QRET_BUILD_PYTHON=ON"
+        run: |
+          python -m pip install --upgrade pip pytest coverage numpy
+          python -m pip install -vvv dist/*.tar.gz
+        shell: bash
+
+      - name: Run tests
+        run: python -m pytest quration-core/python/tests
+        shell: bash
+
+  merge:
+    needs: [test-wheel, test-sdist]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Merge Artifacts
+        uses: actions/upload-artifact/merge@v4
+        with:
+          name: pyqret
+          pattern: pyqret-*
+
+  release:
+    if: github.event_name == 'release'
+    needs: [merge]
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Download merged artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: pyqret
+          path: dist
+
+      - name: Upload artifact to release
+        uses: softprops/action-gh-release@v2
+        with:
+          files: dist/*
diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 0000000..72ed58e
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1,3 @@
+graft include
+graft lib
+graft lib64
diff --git a/pyproject.toml b/pyproject.toml
index 4162c73..5da1dfd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 name = "pyqret"
 description = "Python wrapper of QRET"
-readme = "quration-core/python/README.md"
+readme = "README.md"
 required-python = ">=3.10"
 
 # authors =
@@ -69,6 +69,8 @@ wheel.py-api = "cp312"
 
 # Include Python package from the non-root location.
 wheel.packages = ["quration-core/python/pyqret"]
+wheel.exclude = ["include/**", "lib/**", "lib64/**"]
+sdist.include = ["externals/**", "quration-core/src/**"]
 
 [tool.scikit-build.cmake.define]
 # nanobind requires libraries to be position-independent in order to link correctly
diff --git a/quration-core/python/pyqret/__init__.py b/quration-core/python/pyqret/__init__.py
index 8e53219..f785f74 100644
--- a/quration-core/python/pyqret/__init__.py
+++ b/quration-core/python/pyqret/__init__.py
@@ -6,6 +6,14 @@
 
 from typing_extensions import Self
 
+import importlib.util
+
+import os
+
+import platform
+
+from pathlib import Path
+
 from . import _qret_impl as _M
 
 if TYPE_CHECKING:
@@ -281,3 +289,43 @@ def __next__(self):  # noqa:ANN204
         ret = self._convert_to()
         ret._impl = next(self._iter)
         return ret
+
+
+_ENV_PATH = "GRIDSYNTH_PATH"
+
+
+def _qret_package_root() -> Path | None:
+    spec = importlib.util.find_spec("pyqret")
+    if spec is None:
+        return None
+    if spec.origin:
+        return Path(spec.origin).resolve().parent
+    return None
+
+
+def _set_gridsynth_env_from_package() -> None:
+    if _ENV_PATH in os.environ:
+        return
+
+    package_root = _qret_package_root()
+    if package_root is None:
+        return
+
+    bin_dir = package_root / "externals" / "newsynth"
+    if not bin_dir.is_dir():
+        return
+
+    candidates = [
+        bin_dir / "gridsynth",
+        bin_dir / "gridsynth.exe",
+    ]
+    if platform.system().lower() == "windows":
+        candidates.reverse()
+
+    for path in candidates:
+        if path.is_file() and os.access(path, os.X_OK):
+            os.environ[_ENV_PATH] = str(path.resolve())
+            break
+
+
+_set_gridsynth_env_from_package()