diff --git a/add-knowledge-column.js b/add-knowledge-column.js
deleted file mode 100644
index c0fe206..0000000
--- a/add-knowledge-column.js
+++ /dev/null
@@ -1,50 +0,0 @@
-const {sequelize} = require('./config/database');
-
-(async () => {
-  try {
-    await sequelize.authenticate();
-    console.log('✅ Database connected');
-    
-    // Check current columns
-    const [cols] = await sequelize.query('DESCRIBE context');
-    console.log('\n📋 Current columns:');
-    cols.forEach(c => console.log(`   - ${c.Field}`));
-    
-    const columnNames = cols.map(c => c.Field);
-    
-    // Add knowledge column if not exists
-    if (!columnNames.includes('knowledge')) {
-      await sequelize.query(`
-        ALTER TABLE context 
-        ADD COLUMN knowledge TEXT NULL
-        COMMENT 'Additional knowledge or information'
-      `);
-      console.log('\n✅ Added knowledge column');
-    } else {
-      console.log('\n✅ knowledge column already exists');
-    }
-    
-    // Add status column if not exists
-    if (!columnNames.includes('status')) {
-      await sequelize.query(`
-        ALTER TABLE context 
-        ADD COLUMN status INT DEFAULT 0 
-        COMMENT '0: Draft, 1: Enriched, 2: Prompt_Ready, 3: Generating, 4: Image_Ready, 5: Approved'
-      `);
-      console.log('✅ Added status column');
-    } else {
-      console.log('✅ status column already exists');
-    }
-    
-    // Show final structure
-    const [finalCols] = await sequelize.query('DESCRIBE context');
-    console.log('\n📊 Final Context table structure:');
-    finalCols.forEach((c, i) => console.log(`   ${i+1}. ${c.Field} (${c.Type})`));
-    
-    process.exit(0);
-  } catch (error) {
-    console.error('❌ Error:', error.message);
-    console.error(error.stack);
-    process.exit(1);
-  }
-})();
diff --git a/app.js b/app.js
index 9d08327..e94ebaf 100644
--- a/app.js
+++ b/app.js
@@ -20,6 +20,7 @@ const authRoutes = require('./routes/authRoutes');
 const schoolRoutes = require('./routes/schoolRoutes');
 const classRoutes = require('./routes/classRoutes');
 const academicYearRoutes = require('./routes/academicYearRoutes');
+const categoryRoutes = require('./routes/categoryRoutes');
 const subjectRoutes = require('./routes/subjectRoutes');
 const userRoutes = require('./routes/userRoutes');
 const studentRoutes = require('./routes/studentRoutes');
@@ -217,6 +218,7 @@ app.use('/api/auth', authRoutes);
 app.use('/api/schools', schoolRoutes);
 app.use('/api/classes', classRoutes);
 app.use('/api/academic-years', academicYearRoutes);
+app.use('/api/categories', categoryRoutes);
 app.use('/api/subjects', subjectRoutes);
 app.use('/api/users', userRoutes);
 app.use('/api/students', studentRoutes);
diff --git a/controllers/categoryController.js b/controllers/categoryController.js
new file mode 100644
index 0000000..3e90e42
--- /dev/null
+++ b/controllers/categoryController.js
@@ -0,0 +1,354 @@
+const { Categories, Subject } = require('../models');
+const { cacheUtils } = require('../config/redis');
+
+/**
+ * Categories Controller - Quản lý danh mục
+ */
+class CategoryController {
+  /**
+   * Get all categories with pagination and caching
+   */
+  async getAllCategories(req, res, next) {
+    try {
+      const { page = 1, limit = 50, is_active } = req.query;
+      const offset = (page - 1) * limit;
+      
+      // Generate cache key
+      const cacheKey = `categories:list:${page}:${limit}:${is_active || 'all'}`;
+      
+      // Try to get from cache first
+      const cached = await cacheUtils.get(cacheKey);
+      if (cached) {
+        return res.json({
+          success: true,
+          data: cached,
+          cached: true,
+        });
+      }
+      
+      // Build query conditions
+      const where = {};
+      if (is_active !== undefined) where.is_active = is_active === 'true';
+      
+      // Query from database (through ProxySQL)
+      const { count, rows } = await Categories.findAndCountAll({
+        where,
+        limit: parseInt(limit),
+        offset: parseInt(offset),
+        order: [['category_code', 'ASC']],
+      });
+      
+      const result = {
+        categories: rows,
+        pagination: {
+          total: count,
+          page: parseInt(page),
+          limit: parseInt(limit),
+          totalPages: Math.ceil(count / limit),
+        },
+      };
+      
+      // Cache the result
+      await cacheUtils.set(cacheKey, result, 7200); // Cache for 2 hours
+      
+      res.json({
+        success: true,
+        data: result,
+        cached: false,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Get category by ID with caching
+   */
+  async getCategoryById(req, res, next) {
+    try {
+      const { id } = req.params;
+      const cacheKey = `category:${id}`;
+      
+      // Try cache first
+      const cached = await cacheUtils.get(cacheKey);
+      if (cached) {
+        return res.json({
+          success: true,
+          data: cached,
+          cached: true,
+        });
+      }
+      
+      // Query from database
+      const category = await Categories.findByPk(id);
+      
+      if (!category) {
+        return res.status(404).json({
+          success: false,
+          message: 'Category not found',
+        });
+      }
+      
+      // Cache the result
+      await cacheUtils.set(cacheKey, category, 7200); // Cache for 2 hours
+      
+      res.json({
+        success: true,
+        data: category,
+        cached: false,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Get category by code with caching
+   */
+  async getCategoryByCode(req, res, next) {
+    try {
+      const { code } = req.params;
+      const cacheKey = `category:code:${code}`;
+      
+      // Try cache first
+      const cached = await cacheUtils.get(cacheKey);
+      if (cached) {
+        return res.json({
+          success: true,
+          data: cached,
+          cached: true,
+        });
+      }
+      
+      // Query from database
+      const category = await Categories.findOne({
+        where: { category_code: code },
+      });
+      
+      if (!category) {
+        return res.status(404).json({
+          success: false,
+          message: 'Category not found',
+        });
+      }
+      
+      // Cache the result
+      await cacheUtils.set(cacheKey, category, 7200); // Cache for 2 hours
+      
+      res.json({
+        success: true,
+        data: category,
+        cached: false,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Create new category
+   */
+  async createCategory(req, res, next) {
+    try {
+      const categoryData = req.body;
+      
+      const category = await Categories.create(categoryData);
+      
+      await cacheUtils.deletePattern('categories:list:*');
+      
+      res.status(201).json({
+        success: true,
+        message: 'Category created successfully',
+        data: category,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Update category
+   */
+  async updateCategory(req, res, next) {
+    try {
+      const { id } = req.params;
+      const updates = req.body;
+      
+      const category = await Categories.findByPk(id);
+      
+      if (!category) {
+        return res.status(404).json({
+          success: false,
+          message: 'Category not found',
+        });
+      }
+      
+      await category.update(updates);
+      
+      await cacheUtils.delete(`category:${id}`);
+      await cacheUtils.deletePattern('categories:list:*');
+      
+      res.json({
+        success: true,
+        message: 'Category updated successfully',
+        data: category,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Delete category
+   */
+  async deleteCategory(req, res, next) {
+    try {
+      const { id } = req.params;
+      
+      const category = await Categories.findByPk(id);
+      
+      if (!category) {
+        return res.status(404).json({
+          success: false,
+          message: 'Category not found',
+        });
+      }
+      
+      await category.destroy();
+      
+      await cacheUtils.delete(`category:${id}`);
+      await cacheUtils.deletePattern('categories:list:*');
+      
+      res.json({
+        success: true,
+        message: 'Category deleted successfully',
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Get active categories (frequently used)
+   */
+  async getActiveCategories(req, res, next) {
+    try {
+      const cacheKey = 'categories:active';
+      
+      // Try cache first
+      const cached = await cacheUtils.get(cacheKey);
+      if (cached) {
+        return res.json({
+          success: true,
+          data: cached,
+          cached: true,
+        });
+      }
+      
+      // Query from database
+      const categories = await Categories.findAll({
+        where: { is_active: true },
+        order: [['category_code', 'ASC']],
+      });
+      
+      // Cache for 4 hours (this data changes infrequently)
+      await cacheUtils.set(cacheKey, categories, 14400);
+      
+      res.json({
+        success: true,
+        data: categories,
+        cached: false,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Get category datatypes
+   */
+  async getCategoryDatatypes(req, res, next) {
+    try {
+      const datatypes = Categories.rawAttributes;
+      res.json({
+        success: true,
+        data: datatypes,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+
+  /**
+   * Get subjects by category ID
+   */
+  async getSubjectsByCategory(req, res, next) {
+    try {
+      const { id } = req.params;
+      const { page = 1, limit = 50, is_active } = req.query;
+      const offset = (page - 1) * limit;
+
+      // Generate cache key
+      const cacheKey = `category:${id}:subjects:${page}:${limit}:${is_active || 'all'}`;
+
+      // Try cache first
+      const cached = await cacheUtils.get(cacheKey);
+      if (cached) {
+        return res.json({
+          success: true,
+          data: cached,
+          cached: true,
+        });
+      }
+
+      // Check if category exists
+      const category = await Categories.findByPk(id);
+      if (!category) {
+        return res.status(404).json({
+          success: false,
+          message: 'Category not found',
+        });
+      }
+
+      // Build query conditions
+      const where = { category_id: id };
+      if (is_active !== undefined) where.is_active = is_active === 'true';
+
+      // Query subjects
+      const { count, rows } = await Subject.findAndCountAll({
+        where,
+        limit: parseInt(limit),
+        offset: parseInt(offset),
+        order: [['subject_code', 'ASC']],
+      });
+
+      const result = {
+        category: {
+          id: category.id,
+          category_code: category.category_code,
+          category_name: category.category_name,
+        },
+        subjects: rows,
+        pagination: {
+          total: count,
+          page: parseInt(page),
+          limit: parseInt(limit),
+          totalPages: Math.ceil(count / limit),
+        },
+      };
+
+      // Cache the result
+      await cacheUtils.set(cacheKey, result, 3600); // Cache for 1 hour
+
+      res.json({
+        success: true,
+        data: result,
+        cached: false,
+      });
+    } catch (error) {
+      next(error);
+    }
+  }
+}
+
+module.exports = new CategoryController();
diff --git a/models/Categories.js b/models/Categories.js
new file mode 100644
index 0000000..e254064
--- /dev/null
+++ b/models/Categories.js
@@ -0,0 +1,30 @@
+const { DataTypes } = require('sequelize');
+const { sequelize } = require('../config/database');
+
+const Categories = sequelize.define('Categories', {
+  id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true },
+  category_code: { type: DataTypes.STRING(20), unique: true, allowNull: false },
+  category_name: { type: DataTypes.STRING(100), allowNull: false },
+  category_thumbnail: { type: DataTypes.STRING(255) },
+  category_name_en: { type: DataTypes.STRING(100) },
+  description: { type: DataTypes.TEXT },
+  is_active: { type: DataTypes.BOOLEAN, defaultValue: true },
+  is_premium: { type: DataTypes.BOOLEAN, defaultValue: false, comment: 'Nội dung premium' },
+  is_training: { type: DataTypes.BOOLEAN, defaultValue: false, comment: 'Nội dung đào tạo nhân sự' },
+  is_public: { type: DataTypes.BOOLEAN, defaultValue: false, comment: 'Nội dung tự học công khai' },
+  required_role: { type: DataTypes.STRING(50), comment: 'Role yêu cầu' },
+  min_subscription_tier: { type: DataTypes.STRING(50), comment: 'Gói tối thiểu: basic, premium, vip' },
+  created_at: { type: DataTypes.DATE, allowNull: false, defaultValue: DataTypes.NOW },
+  updated_at: { type: DataTypes.DATE, allowNull: false, defaultValue: DataTypes.NOW },
+}, {
+  tableName: 'Categories',
+  timestamps: true,
+  underscored: true,
+  indexes: [
+    { fields: ['is_premium'] },
+    { fields: ['is_training'] },
+    { fields: ['is_public'] },
+  ],
+});
+
+module.exports = Categories;
diff --git a/models/Subject.js b/models/Subject.js
index d594f5d..0a8d422 100644
--- a/models/Subject.js
+++ b/models/Subject.js
@@ -3,6 +3,7 @@ const { sequelize } = require('../config/database');
 
 const Subject = sequelize.define('subjects', {
   id: { type: DataTypes.UUID, defaultValue: DataTypes.UUIDV4, primaryKey: true },
+  category_id: { type: DataTypes.UUID, allowNull: false, comment: 'Danh mục chủ đề' },
   subject_code: { type: DataTypes.STRING(20), unique: true, allowNull: false },
   subject_name: { type: DataTypes.STRING(100), allowNull: false },
   subject_name_en: { type: DataTypes.STRING(100) },
diff --git a/models/index.js b/models/index.js
index b390b2a..834a2da 100644
--- a/models/index.js
+++ b/models/index.js
@@ -20,6 +20,7 @@ const StaffContract = require('./StaffContract');
 
 // Group 3: Academic Structure
 const AcademicYear = require('./AcademicYear');
+const Categories = require('./Categories');
 const Subject = require('./Subject');
 const Class = require('./Class');
 const ClassSchedule = require('./ClassSchedule');
@@ -149,6 +150,10 @@ const setupRelationships = () => {
   ClassSchedule.belongsTo(TeacherDetail, { foreignKey: 'teacher_id', as: 'teacher' });
   
   // Learning Content relationships (NEW)
+  // Categories -> Subject (1:N)
+  Categories.hasMany(Subject, { foreignKey: 'category_id', as: 'subjects' });
+  Subject.belongsTo(Categories, { foreignKey: 'category_id', as: 'category' });
+  
   // Subject -> Chapter (1:N)
   Subject.hasMany(Chapter, { foreignKey: 'subject_id', as: 'chapters' });
   Chapter.belongsTo(Subject, { foreignKey: 'subject_id', as: 'subject' });
@@ -277,6 +282,7 @@ module.exports = {
   
   // Group 3: Academic Structure
   AcademicYear,
+  Categories,
   Subject,
   Class,
   ClassSchedule,
diff --git a/quick-fix-bcrypt.bat b/quick-fix-bcrypt.bat
deleted file mode 100644
index 242a772..0000000
--- a/quick-fix-bcrypt.bat
+++ /dev/null
@@ -1,23 +0,0 @@
-@echo off
-REM Windows batch script to fix bcrypt on remote server
-REM Usage: quick-fix-bcrypt.bat
-
-set SERVER=root@senaai.tech
-set PROJECT_PATH=/var/www/services/sena_db_api
-
-echo ================================================================
-echo   Quick Fix Bcrypt Script
-echo   Server: %SERVER%
-echo ================================================================
-echo.
-
-echo Connecting to server and fixing bcrypt...
-echo.
-
-ssh %SERVER% "cd %PROJECT_PATH% && npm rebuild bcrypt --build-from-source && npm rebuild && mkdir -p logs && echo. && echo [SUCCESS] Bcrypt rebuilt! && echo. && pm2 restart all 2>nul || pm2 start start.json && echo. && pm2 list"
-
-echo.
-echo ================================================================
-echo   Done! Check the output above.
-echo ================================================================
-pause
diff --git a/quick-fix-bcrypt.sh b/quick-fix-bcrypt.sh
deleted file mode 100644
index 673fb8f..0000000
--- a/quick-fix-bcrypt.sh
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/bin/bash
-
-# Script tự động rebuild bcrypt và restart PM2
-# Usage: ./quick-fix-bcrypt.sh
-
-SERVER="root@senaai.tech"
-PROJECT_PATH="/var/www/services/sena_db_api"
-
-echo "🔧 Quick fix bcrypt on $SERVER..."
-echo ""
-
-ssh $SERVER << ENDSSH
-cd $PROJECT_PATH && \
-echo "🔨 Rebuilding bcrypt..." && \
-npm rebuild bcrypt --build-from-source && \
-npm rebuild && \
-mkdir -p logs && \
-echo "" && \
-echo "✅ Bcrypt rebuilt successfully!" && \
-echo "" && \
-echo "🔄 Restarting PM2..." && \
-pm2 restart all 2>/dev/null || pm2 start start.json && \
-echo "" && \
-echo "📊 PM2 Status:" && \
-pm2 list && \
-echo "" && \
-echo "✅ All done!"
-ENDSSH
diff --git a/rename-img-prompt.js b/rename-img-prompt.js
deleted file mode 100644
index 9ab1315..0000000
--- a/rename-img-prompt.js
+++ /dev/null
@@ -1,27 +0,0 @@
-const {sequelize} = require('./config/database');
-
-(async () => {
-  try {
-    await sequelize.authenticate();
-    console.log('✅ Database connected');
-    
-    // Rename promptForImage to img_prompt
-    await sequelize.query(`
-      ALTER TABLE context 
-      CHANGE COLUMN promptForImage img_prompt JSON 
-      COMMENT 'Prompt configuration object'
-    `);
-    console.log('✅ Renamed promptForImage to img_prompt');
-    
-    // Show final structure
-    const [cols] = await sequelize.query('DESCRIBE context');
-    console.log('\n📊 Final Context table structure:');
-    cols.forEach((c, i) => console.log(`   ${i+1}. ${c.Field} (${c.Type})`));
-    
-    process.exit(0);
-  } catch (error) {
-    console.error('❌ Error:', error.message);
-    console.error(error.stack);
-    process.exit(1);
-  }
-})();
diff --git a/routes/categoryRoutes.js b/routes/categoryRoutes.js
new file mode 100644
index 0000000..f034220
--- /dev/null
+++ b/routes/categoryRoutes.js
@@ -0,0 +1,36 @@
+const express = require('express');
+const router = express.Router();
+const categoryController = require('../controllers/categoryController');
+
+/**
+ * Category Routes
+ */
+
+// GET /api/categories - Get all categories with pagination
+router.get('/', categoryController.getAllCategories);
+
+// GET /api/categories/active - Get all active categories
+router.get('/active', categoryController.getActiveCategories);
+
+// GET /api/categories/datatypes/schema - Get category datatypes
+router.get('/datatypes/schema', categoryController.getCategoryDatatypes);
+
+// GET /api/categories/code/:code - Get category by code
+router.get('/code/:code', categoryController.getCategoryByCode);
+
+// GET /api/categories/:id - Get category by ID
+router.get('/:id', categoryController.getCategoryById);
+
+// GET /api/categories/:id/subjects - Get subjects by category
+router.get('/:id/subjects', categoryController.getSubjectsByCategory);
+
+// POST /api/categories - Create new category
+router.post('/', categoryController.createCategory);
+
+// PUT /api/categories/:id - Update category
+router.put('/:id', categoryController.updateCategory);
+
+// DELETE /api/categories/:id - Delete category
+router.delete('/:id', categoryController.deleteCategory);
+
+module.exports = router;