diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
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+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,84 @@
+name: CI
+
+# details & description at http://3bb.cc/blog/2020/09/11/github-ci/
+
+# Controls when the action will run. Triggers the workflow on push for any branch, and
+# pull requests to master
+on:
+  push:
+  pull_request:
+    branches: [ endless ]
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  test:
+    name: ${{ matrix.lisp }} on ${{ matrix.os }}
+    strategy:
+      matrix:
+      # current ccl-bin has a flaky zip file, so roswell can't install it.
+      # Specify a version that works for now.
+        lisp: [sbcl-bin, ccl-bin/1.12]
+        os: [ windows-latest, ubuntu-latest, macos-latest]
+
+    # run the job on every combination of "lisp" and "os" above
+    runs-on: ${{ matrix.os }}
+
+    # default to msys2 shell on windows, since roswell install-for-ci.sh tries to install using pacman
+    defaults:
+      run:
+        shell: ${{ fromJSON('[ "bash", "msys2 {0}" ]') [ matrix.os == 'windows-latest' ] }}
+
+    steps:
+
+    # use setup-msys2
+    - uses: msys2/setup-msys2@v2
+      if: matrix.os == 'windows-latest'
+      with:
+        path-type: inherit
+        # list any extra packages we want installed
+
+        # for example the following would be enough for us to build sbcl
+        # from git:
+        # install: 'git base-devel unzip mingw-w64-x86_64-gcc mingw64/mingw-w64-x86_64-zlib'
+
+
+    # tell git not to convert line endings
+    # change roswell install dir and add it to path
+    - name: windows specific settings
+      if: matrix.os == 'windows-latest'
+      run: |
+        git config --global core.autocrlf false
+        echo "ROSWELL_INSTALL_DIR=$HOME/ros" >> $GITHUB_ENV
+        echo "$HOME/ros/bin" >> $GITHUB_PATH
+
+    # Check out your repository under $GITHUB_WORKSPACE, so your job can access it
+    - uses: actions/checkout@v2
+
+    - name: cache .roswell
+      id: cache-dot-roswell
+      uses: actions/cache@v1
+      with:
+        path: ~/.roswell
+        key: ${{ runner.os }}-dot-roswell-${{ matrix.lisp }}-${{ hashFiles('**/*.asd') }}
+        restore-keys: |
+          ${{ runner.os }}-dot-roswell-${{ matrix.lisp }}-
+          ${{ runner.os }}-dot-roswell-
+
+    - name: install roswell
+      # always run install, since it does some global installs and setup that isn't cached
+      env:
+       LISP: ${{ matrix.lisp }}
+      run: curl -L https://raw.githubusercontent.com/roswell/roswell/master/scripts/install-for-ci.sh | sh -x
+
+    - name: run lisp
+      continue-on-error: true
+      run: |
+        ros -e '(format t "~a:~a on ~a~%...~%~%" (lisp-implementation-type) (lisp-implementation-version) (machine-type))'
+        ros -e '(format t " fixnum bits:~a~%" (integer-length most-positive-fixnum))'
+        ros -e "(ql:quickload 'trivial-features)" -e '(format t "features = ~s~%" *features*)'
+    - name: update ql dist if we have one cached
+      run: ros -e "(ql:update-all-dists :prompt nil)"
+
+    - name: load code and run tests
+      run: |
+        ros -e '(handler-bind (#+asdf3.2(asdf:bad-SYSTEM-NAME (function MUFFLE-WARNING))) (handler-case (ql:quickload :osc) (error (a) (format t "caught error ~s~%~a~%" a a) (uiop:quit 123))))' -e '(osc:run-tests)'