diff --git a/setup.sh b/setup.sh
index d010b44..881ff17 100755
--- a/setup.sh
+++ b/setup.sh
@@ -45,6 +45,13 @@ fi
 
 echo "[setup] Harness source: $HARNESS_SRC"
 
+# --- Ensure git repo exists ---
+if ! git rev-parse --git-dir &>/dev/null; then
+    echo "[setup] No git repo found. Initializing..."
+    git init
+    git checkout -b main 2>/dev/null || true
+fi
+
 # --- Scaffold .loop/ ---
 PROJECT_ROOT="$(pwd)"
 LOOP_DIR="$PROJECT_ROOT/.loop"