diff --git a/tools/kernel_inventory.py b/tools/kernel_inventory.py
new file mode 100644
index 0000000..43acd30
--- /dev/null
+++ b/tools/kernel_inventory.py
@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""Export a JSON inventory of mcoplib kernel files."""
+
+from __future__ import annotations
+
+
+import argparse
+import json
+from pathlib import Path
+
+
+PATTERNS = ["kernel/**/*", "op/**/*.cu", "include/**/*"]
+
+
+def inventory(root: Path) -> dict[str, object]:
+    if not root.is_dir():
+        raise NotADirectoryError(f"inventory root is not a directory: {root}")
+
+    files: list[dict[str, object]] = []
+    for pattern in PATTERNS:
+        for path in sorted(root.glob(pattern)):
+            if path.is_file():
+                rel = path.relative_to(root).as_posix()
+                files.append(
+                    {"path": rel, "bytes": path.stat().st_size, "pattern": pattern}
+                )
+    by_pattern: dict[str, int] = {}
+    for item in files:
+        by_pattern[item["pattern"]] = by_pattern.get(item["pattern"], 0) + 1
+    return {
+        "root": str(root),
+        "count": len(files),
+        "by_pattern": by_pattern,
+        "files": files,
+    }
+
+
+def self_test() -> None:
+    data = inventory(Path.cwd())
+    if not isinstance(data["files"], list):
+        raise RuntimeError(f"self-test failed: {data}")
+    print(json.dumps({"ok": True, "count": data["count"]}, ensure_ascii=False))
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--root", default=".", help="Repository root to scan.")
+    parser.add_argument("--self-test", action="store_true")
+    args = parser.parse_args()
+    if args.self_test:
+        self_test()
+        return 0
+    root = Path(args.root)
+    if not root.is_dir():
+        parser.error(f"--root is not a directory: {root}")
+    print(json.dumps(inventory(root), ensure_ascii=False, indent=2))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())