diff --git a/app/src/protocol_ifc.py b/app/src/protocol_ifc.py
new file mode 100644
index 0000000..90ee8f1
--- /dev/null
+++ b/app/src/protocol_ifc.py
@@ -0,0 +1,43 @@
+from abc import abstractmethod
+import weakref
+
+if __name__ == "app.src.protocol_ifc":
+    from app.src.iter_registry import AbstractIterMeta
+    from app.src.async_ifc import AsyncIfc
+else:  # pragma: no cover
+    from iter_registry import AbstractIterMeta
+    from async_ifc import AsyncIfc
+
+
+class ProtocolIfc(metaclass=AbstractIterMeta):
+
+    @abstractmethod
+    def __init__(self, addr, ifc: "AsyncIfc", server_side: bool,
+                 client_mode: bool = False, id_str=b''):
+        pass  # pragma: no cover
+
+    @abstractmethod
+    def close(self):
+        pass  # pragma: no cover
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc, tb):
+        self.close()
+
+
+class Test():
+    def test_method(self):
+        return self
+
+
+class ProtocolIfcImpl(ProtocolIfc, Test):
+    _registry = []
+
+    def __init__(self, addr, ifc: "AsyncIfc", server_side: bool,
+                 client_mode: bool = False, id_str=b''):
+        self._registry.append(weakref.ref(self))
+
+    def close(self):
+        pass  # pragma: no cover