diff --git a/tools/unit_test_inventory.py b/tools/unit_test_inventory.py
new file mode 100644
index 0000000..0da1c80
--- /dev/null
+++ b/tools/unit_test_inventory.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+"""Export mcoplib unit test metadata as JSON."""
+
+from __future__ import annotations
+
+import argparse
+import ast
+import json
+from pathlib import Path
+
+
+def _test_functions(path: Path) -> tuple[list[str], str]:
+    try:
+        tree = ast.parse(path.read_text(encoding="utf-8", errors="replace"))
+    except SyntaxError as exc:
+        return [], f"{exc.__class__.__name__}: {exc}"
+    tests = sorted(
+        node.name
+        for node in ast.walk(tree)
+        if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef)) and node.name.startswith("test_")
+    )
+    return tests, ""
+
+
+def inventory(root: Path) -> dict[str, object]:
+    tests = []
+    for path in sorted((root / "unit_test").glob("test_*.py")):
+        funcs, parse_error = _test_functions(path)
+        tests.append(
+            {
+                "path": path.relative_to(root).as_posix(),
+                "test_functions": funcs,
+                "count": len(funcs),
+                "parse_error": parse_error,
+            }
+        )
+    return {
+        "file_count": len(tests),
+        "test_function_count": sum(item["count"] for item in tests),
+        "parse_error_count": sum(1 for item in tests if item["parse_error"]),
+        "tests": tests,
+    }
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--root", type=Path, default=Path.cwd())
+    parser.add_argument("--output", type=Path)
+    args = parser.parse_args()
+
+    text = json.dumps(inventory(args.root), indent=2, ensure_ascii=False)
+    if args.output:
+        args.output.write_text(text + "\n", encoding="utf-8")
+    else:
+        print(text)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/unit_test/test_unit_test_inventory.py b/unit_test/test_unit_test_inventory.py
new file mode 100644
index 0000000..4d60edc
--- /dev/null
+++ b/unit_test/test_unit_test_inventory.py
@@ -0,0 +1,28 @@
+import tempfile
+import unittest
+from pathlib import Path
+
+from tools.unit_test_inventory import inventory
+
+
+class UnitTestInventoryTest(unittest.TestCase):
+    def test_counts_test_functions(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            root = Path(tmpdir)
+            unit = root / "unit_test"
+            unit.mkdir()
+            (unit / "test_demo.py").write_text(
+                "def test_a(): pass\n"
+                "async def test_async_case(): pass\n"
+                "def helper(): pass\n",
+                encoding="utf-8",
+            )
+
+            report = inventory(root)
+
+        self.assertEqual(report["file_count"], 1)
+        self.assertEqual(report["test_function_count"], 2)
+
+
+if __name__ == "__main__":
+    unittest.main()