diff --git a/git_why.py b/git_why.py
index 6d62fed..24aeda9 100755
--- a/git_why.py
+++ b/git_why.py
@@ -18,6 +18,8 @@
 import sys
 from fnmatch import fnmatch
 
+__version__ = "0.1.0"  # single source of truth; keep in sync with pyproject.toml
+
 KEYS = ["Why", "Why-Prompt", "Why-Rationale", "Why-Alternatives",
         "Why-Spec", "Why-Agent", "Why-Session", "Why-Confidence"]
 LABEL = {"Why-Prompt": "prompt", "Why-Rationale": "rationale",
@@ -425,6 +427,9 @@ def cmd_init(args):
 
 def main():
     argv = sys.argv[1:]
+    if argv and argv[0] in ("-V", "--version"):
+        print(f"git why {__version__}")
+        return 0
     if not argv or argv[0] not in SUBCOMMANDS:
         if argv and argv[0] in ("-h", "--help"):
             return cmd_show("-h")
diff --git a/test/smoke.sh b/test/smoke.sh
index 5008f76..130e644 100755
--- a/test/smoke.sh
+++ b/test/smoke.sh
@@ -23,6 +23,9 @@ git config user.email t@example.com
 git config user.name Tester
 big() { printf '%s line %s\n' "$1" $(seq 1 40) > "$1"; git add "$1"; }
 
+# --- version ---------------------------------------------------------------
+gw --version | grep -qE "^git why [0-9]+\.[0-9]+" || fail "git why --version"
+
 # ---- default: nudge (never blocks) -------------------------------------
 gw init >/dev/null
 [ "$(git config --get why.strict)" = "nudge" ] || fail "default level is not nudge"