diff --git a/lib/strings/default.nix b/lib/strings/default.nix
new file mode 100644
index 0000000..dccb09f
--- /dev/null
+++ b/lib/strings/default.nix
@@ -0,0 +1,15 @@
+# SPDX-FileCopyrightText: 2024 Clicks Codes
+#
+# SPDX-License-Identifier: GPL-3.0-only
+
+{ lib, inputs, ... }:
+{
+  strings = {
+    getCommonPrefix =
+      a: b:
+      let
+        prefixLength = lib.strings.commonPrefixLength a b;
+      in
+      builtins.substring 0 prefixLength a;
+  };
+}