diff --git a/action.yml b/action.yml
new file mode 100644
index 0000000..ca14074
--- /dev/null
+++ b/action.yml
@@ -0,0 +1,9 @@
+name: 'Build and Install Cadius'
+description: 'Builds and installs the Cadius tool for Apple II ProDOS disk images'
+runs:
+  using: "composite"
+  steps:
+    - run: >
+        git clone https://github.com/mach-kernel/cadius /tmp/cadius &&
+        make -C /tmp/cadius &&
+        sudo make -C /tmp/cadius install