--- a/mercurial/configuration/__init__.py	Wed Oct 23 01:12:52 2024 +0200
+++ b/mercurial/configuration/__init__.py	Wed Oct 23 00:43:17 2024 +0200
@@ -0,0 +1,36 @@
+# configuration related constants
+
+from __future__ import annotations
+
+from typing import (
+    List,
+    Tuple,
+    Union,
+)
+
+# keep typing simple for now
+ConfigLevelT = str
+LEVEL_USER = 'user'  # "user" is the default level and never passed explicitly
+LEVEL_LOCAL = 'local'
+LEVEL_GLOBAL = 'global'
+LEVEL_SHARED = 'shared'
+LEVEL_NON_SHARED = 'non_shared'
+EDIT_LEVELS = (
+    LEVEL_USER,
+    LEVEL_LOCAL,
+    LEVEL_GLOBAL,
+    LEVEL_SHARED,
+    LEVEL_NON_SHARED,
+)
+
+ConfigItemT = Tuple[bytes, bytes, bytes, bytes]
+ResourceIDT = Tuple[bytes, bytes]
+FileRCT = bytes
+ComponentT = Tuple[
+    bytes,
+    Union[
+        List[ConfigItemT],
+        FileRCT,
+        ResourceIDT,
+    ],
+]