diff --git a/core/math/src/math.ts b/core/math/src/math.ts
index e8cb7cd00..9d4ab94b7 100644
--- a/core/math/src/math.ts
+++ b/core/math/src/math.ts
@@ -252,17 +252,3 @@ export const hex = (bytes: Uint8Array): string => {
   }
   return str;
 };
-
-let clientId: string | null = null;
-export const getClientId = (): string => {
-  if (clientId != null) {
-    return clientId;
-  }
-  // else
-  clientId = localStorage.getItem('client-id');
-  if (clientId == null) {
-    clientId = random.uuid;
-    localStorage.setItem('client-id', clientId);
-  }
-  return clientId;
-};
diff --git a/core/util/package.json b/core/util/package.json
index ea868dfc7..11566edf7 100644
--- a/core/util/package.json
+++ b/core/util/package.json
@@ -32,6 +32,8 @@
     "url": "https://github.com/AliMD/alwatr/issues"
   },
   "dependencies": {
-    "tslib": "^2.5.0"
+    "tslib": "^2.5.0",
+    "@alwatr/math": "^0.29.0",
+    "@alwatr/type": "^0.29.0"
   }
 }
diff --git a/core/util/src/client-id.ts b/core/util/src/client-id.ts
new file mode 100644
index 000000000..9b280ada6
--- /dev/null
+++ b/core/util/src/client-id.ts
@@ -0,0 +1,16 @@
+import {random} from '@alwatr/math';
+
+let clientId: string | null = null;
+
+export const getClientId = (): string => {
+  if (clientId != null) {
+    return clientId;
+  }
+  // else
+  clientId = localStorage.getItem('client-id');
+  if (clientId == null) {
+    clientId = random.uuid;
+    localStorage.setItem('client-id', clientId);
+  }
+  return clientId;
+};
diff --git a/core/util/src/index.ts b/core/util/src/index.ts
index e36815a83..bc5a45ebe 100644
--- a/core/util/src/index.ts
+++ b/core/util/src/index.ts
@@ -1 +1,4 @@
 export * from './delay.js';
+export * from './json.js';
+export * from './local-storage.js';
+export * from './client-id.js';
diff --git a/core/util/src/json.ts b/core/util/src/json.ts
new file mode 100644
index 000000000..6a2d441e4
--- /dev/null
+++ b/core/util/src/json.ts
@@ -0,0 +1,11 @@
+import type {Stringifyable} from '@alwatr/type';
+
+export const parseJson = <T extends Stringifyable>(str: string): T | null => {
+  try {
+    return JSON.parse(str) as T;
+  }
+  catch (err) {
+    console.error(err);
+    return null;
+  }
+};
diff --git a/core/util/src/local-storage.ts b/core/util/src/local-storage.ts
new file mode 100644
index 000000000..c7d73872a
--- /dev/null
+++ b/core/util/src/local-storage.ts
@@ -0,0 +1,8 @@
+import {parseJson} from './json.js';
+
+import type {Stringifyable} from '@alwatr/type';
+
+export const getLocalStorageItem = <T extends Stringifyable>(name: string, defaultValue: T): T => {
+  const item = localStorage.getItem(name);
+  return item == null ? defaultValue : parseJson(item) ?? defaultValue;
+};
diff --git a/core/util/tsconfig.json b/core/util/tsconfig.json
index d26028499..f3c2df152 100644
--- a/core/util/tsconfig.json
+++ b/core/util/tsconfig.json
@@ -9,5 +9,8 @@
 
   "include": ["src/**/*.ts"],
   "exclude": [],
-  "references": [{"path": "../math"}]
+  "references": [
+    {"path": "../type"},
+    {"path": "../math"},
+  ]
 }
diff --git a/demo/math/translate-unicode-digits.ts b/demo/math/translate-unicode-digits.ts
index cc4f2719f..59f3547b1 100644
--- a/demo/math/translate-unicode-digits.ts
+++ b/demo/math/translate-unicode-digits.ts
@@ -1,4 +1,4 @@
-import {UnicodeDigits, getClientId} from '@alwatr/math';
+import {UnicodeDigits} from '@alwatr/math';
 
 const unicodeDigits = new UnicodeDigits('fa', 'all');
 
@@ -27,6 +27,3 @@ for (let i = count; i > 0; i--) {
 }
 
 console.log((count / (Date.now() - start)) * 1000);
-
-console.log('client-id', getClientId());
-console.log('client-id', getClientId());