diff --git a/src/categories/unread.ts b/src/categories/unread.ts
new file mode 100644
index 00000000..2cb34541
--- /dev/null
+++ b/src/categories/unread.ts
@@ -0,0 +1,58 @@
+import db from '../database';
+
+
+interface CategoriesModel {
+  markAsRead(jids: number[], uid: number): Promise<void>;
+  
+  markAsUnreadForAll(jid: number): Promise<void>;
+  
+  hasReadCategories(jids: number[], uid: number): Promise<boolean[]>;
+  
+  hasReadCategory(jid: number, uid: number): Promise<boolean>;
+}
+
+
+export default function setupCategoriesModel(Categories: CategoriesModel): void {
+  
+  Categories.markAsRead = async function (jids: number[], uid: number): Promise<void> {
+    
+    if (!Array.isArray(jids) || !jids.length || uid < 1) {
+      return;
+    }
+    let keys = jids.map(jid => `jid:${jid}:read_by_uid`);
+    const hasRead = await db.isMemberOfSet(keys, uid);
+    keys = keys.filter((key, index) => !hasRead[index]);
+    await db.setAdd(keys, uid);
+  };
+
+  
+  
+  Categories.hasReadCategories = async function (jids: number[], uid: number): Promise<boolean[]> {
+    if (uid < 1) {
+      return jids.map(() => false);
+    }
+
+    
+    const set = jids.map(jid => `jid:${jid}:read_by_uid`);
+    return await db.isMemberOfSet(set, uid);
+  };
+
+    Categories.markAsUnreadForAll = async function (jid: number): Promise<void> {
+    if (!jid) {
+      return;
+    }
+    await db.delete(`jid:${jid}:read_by_uid`);
+  };
+  
+  
+  Categories.hasReadCategory = async function (jid: number, uid: number): Promise<boolean> {
+    if (uid < 1) {
+      return false;
+    }
+
+
+    #another_typeScript_function
+    
+    return await db.isSetMember(`jid:${jid}:read_by_uid`, uid);
+  };
+}