diff --git a/src/main.py b/src/main.py
index c9e839b..e2b7dcd 100644
--- a/src/main.py
+++ b/src/main.py
@@ -41,6 +41,8 @@ def wrap_json_envelope(data: dict, command: str, exit_code: int = 0) -> dict:
 
 def build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(description='Python porting workspace for the Claude Code rewrite effort')
+    # #180: Add --version flag to match canonical CLI contract
+    parser.add_argument('--version', action='version', version='claw-code 1.0.0 (Python harness)')
     subparsers = parser.add_subparsers(dest='command', required=True)
     subparsers.add_parser('summary', help='render a Markdown summary of the Python porting workspace')
     subparsers.add_parser('manifest', help='print the current Python workspace manifest')
diff --git a/tests/test_exec_route_bootstrap_output_format.py b/tests/test_exec_route_bootstrap_output_format.py
index 899e3c0..534e463 100644
--- a/tests/test_exec_route_bootstrap_output_format.py
+++ b/tests/test_exec_route_bootstrap_output_format.py
@@ -277,3 +277,30 @@ class TestEnvelopeExitCodeMatchesProcessExit:
             'Envelope exit_code must match process exit code:\n' + 
             '\n'.join(mismatches)
         )
+
+
+class TestMetadataFlags:
+    """Cycle #28: --version flag implementation (#180 gap closure)."""
+
+    def test_version_flag_returns_version_text(self) -> None:
+        """--version returns version string and exits successfully."""
+        result = _run(['--version'])
+        assert result.returncode == 0
+        assert 'claw-code' in result.stdout
+        assert '1.0.0' in result.stdout
+
+    def test_help_flag_returns_help_text(self) -> None:
+        """--help returns help text and exits successfully."""
+        result = _run(['--help'])
+        assert result.returncode == 0
+        assert 'usage:' in result.stdout
+        assert 'Python porting workspace' in result.stdout
+
+    def test_help_still_works_after_version_added(self) -> None:
+        """Verify -h and --help both work (no regression)."""
+        result_short = _run(['-h'])
+        result_long = _run(['--help'])
+        assert result_short.returncode == 0
+        assert result_long.returncode == 0
+        assert 'usage:' in result_short.stdout
+        assert 'usage:' in result_long.stdout