diff --git a/types/lib/helpers.d.ts b/types/lib/helpers.d.ts
new file mode 100644
index 0000000..43c851e
--- /dev/null
+++ b/types/lib/helpers.d.ts
@@ -0,0 +1,8 @@
+export type AddValue = {
+    fn: any;
+};
+/**
+ * @typedef {Object} AddValue
+ * @property {import('../types.js').messageFn} fn
+ */
+export function counter(): () => number;