diff --git a/sanic/models/protocol_types.py b/sanic/models/protocol_types.py
new file mode 100644
index 00000000..48616ad5
--- /dev/null
+++ b/sanic/models/protocol_types.py
@@ -0,0 +1,9 @@
+from typing import Protocol, Union
+
+
+class TransportProtocol(Protocol):
+    def get_protocol(self):
+        ...
+
+    def get_extra_info(self, info: str) -> Union[str, bool, None]:
+        ...