diff --git a/attestation_tool.py b/attestation_tool.py
new file mode 100644
index 0000000..93264dc
--- /dev/null
+++ b/attestation_tool.py
@@ -0,0 +1,11 @@
+from urllib.parse import urlparse
+
+# RPC validation
+if not urlparse(args.rpc).scheme:
+    print("❌ Invalid RPC URL format.", file=sys.stderr)
+    sys.exit(2)
+
+# Private key validation
+if args.sign and (len(pk) != 64 or not all(c in "0123456789abcdef" for c in pk.lower())):
+    print("❌ Invalid PRIVATE_KEY format. Should be 64 hexadecimal characters.", file=sys.stderr)
+    sys.exit(2)