diff --git a/.github/workflows/lean_action_ci.yml b/.github/workflows/lean_action_ci.yml
new file mode 100644
index 0000000..c48bd68
--- /dev/null
+++ b/.github/workflows/lean_action_ci.yml
@@ -0,0 +1,14 @@
+name: Lean Action CI
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v5
+      - uses: leanprover/lean-action@v1
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..bfb30ec
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/.lake
diff --git a/Main.lean b/Main.lean
new file mode 100644
index 0000000..762f725
--- /dev/null
+++ b/Main.lean
@@ -0,0 +1,4 @@
+import ShellWall
+
+def main : IO Unit :=
+  IO.println s!"Hello, {hello}!"
diff --git a/ShellWall.lean b/ShellWall.lean
new file mode 100644
index 0000000..873a184
--- /dev/null
+++ b/ShellWall.lean
@@ -0,0 +1,3 @@
+-- This module serves as the root of the `ShellWall` library.
+-- Import modules here that should be built as part of the library.
+import ShellWall.Basic
diff --git a/ShellWall/Basic.lean b/ShellWall/Basic.lean
new file mode 100644
index 0000000..99415d9
--- /dev/null
+++ b/ShellWall/Basic.lean
@@ -0,0 +1 @@
+def hello := "world"
diff --git a/lake-manifest.json b/lake-manifest.json
new file mode 100644
index 0000000..998b24c
--- /dev/null
+++ b/lake-manifest.json
@@ -0,0 +1,5 @@
+{"version": "1.1.0",
+ "packagesDir": ".lake/packages",
+ "packages": [],
+ "name": "ShellWall",
+ "lakeDir": ".lake"}
diff --git a/lakefile.toml b/lakefile.toml
new file mode 100644
index 0000000..0aa1b32
--- /dev/null
+++ b/lakefile.toml
@@ -0,0 +1,10 @@
+name = "ShellWall"
+version = "0.1.0"
+defaultTargets = ["shellwall"]
+
+[[lean_lib]]
+name = "ShellWall"
+
+[[lean_exe]]
+name = "shellwall"
+root = "Main"
diff --git a/lean-toolchain b/lean-toolchain
new file mode 100644
index 0000000..33e0c08
--- /dev/null
+++ b/lean-toolchain
@@ -0,0 +1 @@
+leanprover/lean4:v4.29.1