From b4c8971788c70b09479946ecfa998cff2f1b3953 Mon Sep 17 00:00:00 2001
From: Tom Meagher <tom@meagher.co>
Date: Thu, 8 Aug 2024 20:47:37 -0400
Subject: [PATCH] fix: #4196

---
 .changeset/big-humans-sleep.md            |  5 +++++
 packages/core/src/createStorage.test-d.ts | 12 ++++++++++++
 packages/core/src/createStorage.ts        |  4 ++--
 3 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/big-humans-sleep.md

diff --git a/.changeset/big-humans-sleep.md b/.changeset/big-humans-sleep.md
new file mode 100644
index 0000000000..d06c87ad38
--- /dev/null
+++ b/.changeset/big-humans-sleep.md
@@ -0,0 +1,5 @@
+---
+"@wagmi/core": patch
+---
+
+Made `serialize` and `deserialize` types more permissive.
diff --git a/packages/core/src/createStorage.test-d.ts b/packages/core/src/createStorage.test-d.ts
index 0761cccda9..6bb4c7f300 100644
--- a/packages/core/src/createStorage.test-d.ts
+++ b/packages/core/src/createStorage.test-d.ts
@@ -60,3 +60,15 @@ test('setItem', () => {
   // @ts-expect-error incorrect argument type
   storage.setItem('recentConnectorId', 1n)
 })
+
+test('serialize/deserialize types', () => {
+  createStorage({
+    deserialize(value) {
+      return value
+    },
+    serialize(value) {
+      return value
+    },
+    storage: localStorage,
+  })
+})
diff --git a/packages/core/src/createStorage.ts b/packages/core/src/createStorage.ts
index 5667e8ee89..06854c0b55 100644
--- a/packages/core/src/createStorage.ts
+++ b/packages/core/src/createStorage.ts
@@ -41,9 +41,9 @@ export type BaseStorage = {
 }
 
 export type CreateStorageParameters = {
-  deserialize?: (<T>(value: string) => T) | undefined
+  deserialize?: (<type>(value: string) => type | unknown) | undefined
   key?: string | undefined
-  serialize?: (<T>(value: T) => string) | undefined
+  serialize?: (<type>(value: type | any) => string) | undefined
   storage?: Compute<BaseStorage> | undefined
 }