diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 00000000..656cb12c
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,231 @@
+name: build xo-callback + xo dependencies
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
+  BUILD_TYPE: Release
+
+jobs:
+  build:
+    # The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
+    # You can convert this to a matrix build if you need cross-platform coverage.
+    # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: checkout source
+      uses: actions/checkout@v3
+
+    - name: Install catch2
+      # install catch2.  see [[https://stackoverflow.com/questions/57982945/how-to-apt-get-install-in-a-github-actions-workflow]]
+      run: sudo apt-get install -y catch2
+
+    # ----------------------------------------------------------------
+
+    - name: Clone xo-cmake
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/xo-cmake
+        path: repo/xo-cmake
+
+    - name: Configure xo-cmake
+      run: cmake -B ${{github.workspace}}/build_xo-cmake -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/xo-cmake
+
+    - name: Build xo-cmake (trivial)
+      run: cmake --build ${{github.workspace}}/build_xo-cmake --config ${{env.BUILD_TYPE}}
+
+    - name: Install xo-cmake
+      run: cmake --install ${{github.workspace}}/build_xo-cmake
+
+    # ----------------------------------------------------------------
+
+    - name: Clone indentlog
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/indentlog
+        path: repo/indentlog
+
+    - name: Configure indentlog
+      # configure cmake for indentlog in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_indentlog -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/indentlog
+
+    - name: Build indentlog
+      run: cmake --build ${{github.workspace}}/build_indentlog --config ${{env.BUILD_TYPE}}
+
+    - name: Install indentlog
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_indentlog
+
+    # ----------------------------------------------------------------
+
+    - name: Clone refcnt
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/refcnt
+        path: repo/refcnt
+
+    - name: Configure refcnt
+      # configure cmake for refcnt in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_refcnt -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/refcnt
+
+    - name: Build refcnt
+      run: cmake --build ${{github.workspace}}/build_refcnt --config ${{env.BUILD_TYPE}}
+
+    - name: Install refcnt
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_refcnt
+
+    # ----------------------------------------------------------------
+
+    - name: Clone subsys
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/subsys
+        path: repo/subsys
+
+    - name: Configure subsys
+      # configure cmake for subsys in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_subsys -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/subsys
+
+    - name: Build subsys
+      run: cmake --build ${{github.workspace}}/build_subsys --config ${{env.BUILD_TYPE}}
+
+    - name: Install subsys
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_subsys
+
+    # ----------------------------------------------------------------
+
+    - name: Clone reflect
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/reflect
+        path: repo/reflect
+
+    - name: Configure reflect
+      # configure cmake for reflect in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_reflect -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/reflect
+
+    - name: Build reflect
+      run: cmake --build ${{github.workspace}}/build_reflect --config ${{env.BUILD_TYPE}}
+
+    - name: Install reflect
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_reflect
+
+    # ----------------------------------------------------------------
+
+    - name: Clone callback
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/xo-callback
+        path: repo/callback
+
+    - name: Configure callback
+      # configure cmake for callback in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_callback -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/callback
+
+    - name: Build callback
+      run: cmake --build ${{github.workspace}}/build_callback --config ${{env.BUILD_TYPE}}
+
+    - name: Install callback
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_callback
+
+    # ----------------------------------------------------------------
+
+    - name: Clone webutil
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/xo-webutil
+        path: repo/webutil
+
+    - name: Configure webutil
+      # configure cmake for webutil in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_webutil -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/webutil
+
+    - name: Build webutil
+      run: cmake --build ${{github.workspace}}/build_webutil --config ${{env.BUILD_TYPE}}
+
+    - name: Install webutil
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_webutil
+
+    # ----------------------------------------------------------------
+
+    - name: Clone printjson
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/xo-printjson
+        path: repo/printjson
+
+    - name: Configure printjson
+      # configure cmake for printjson in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_printjson -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/printjson
+
+    - name: Build printjson
+      run: cmake --build ${{github.workspace}}/build_printjson --config ${{env.BUILD_TYPE}}
+
+    - name: Install printjson
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_printjson
+
+    # ----------------------------------------------------------------
+
+    - name: Clone randomgen
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/randomgen
+        path: repo/randomgen
+
+    - name: Configure randomgen
+      # configure cmake for randomgen in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_randomgen -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/randomgen
+
+    - name: Build randomgen
+      run: cmake --build ${{github.workspace}}/build_randomgen --config ${{env.BUILD_TYPE}}
+
+    - name: Install randomgen
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_randomgen
+
+    # ----------------------------------------------------------------
+
+    - name: Clone reactor
+      uses: actions/checkout@v3
+      with:
+        repository: Rconybea/xo-reactor
+        path: repo/reactor
+
+    - name: Configure reactor
+      # configure cmake for reactor in dedicated build directory.
+      run: cmake -B ${{github.workspace}}/build_reactor -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local repo/reactor
+
+    - name: Build reactor
+      run: cmake --build ${{github.workspace}}/build_reactor --config ${{env.BUILD_TYPE}}
+
+    - name: Install reactor
+      # install into ${{github.workspace}}/local
+      run: cmake --install ${{github.workspace}}/build_reactor
+
+    # ----------------------------------------------------------------
+
+    - name: Configure self (websock)
+      # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
+      # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
+      run: cmake -B ${{github.workspace}}/build_websock -DCMAKE_MODULE_PATH=${{github.workspace}}/local/share/cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/local -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/local -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
+
+    - name: Build self (websock)
+      # Build your program with the given configuration
+      run: cmake --build ${{github.workspace}}/build_websock --config ${{env.BUILD_TYPE}}
+
+    - name: Test self (websock)
+      working-directory: ${{github.workspace}}/build_websock
+      # Execute tests defined by the CMake configuration.
+      # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
+      run: ctest -C ${{env.BUILD_TYPE}}