diff --git a/.env b/.env
new file mode 100644
index 000000000..571aa3c6c
--- /dev/null
+++ b/.env
@@ -0,0 +1,5 @@
+POSTGRES_HOST=localhost
+POSTGRES_PORT=5432
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=Mylifeuncut2015
+POSTGRES_DB=postgres
diff --git a/.github/workflows/test.yml-template b/.github/workflows/test.yml-template
new file mode 100644
index 000000000..03d2b7ff2
--- /dev/null
+++ b/.github/workflows/test.yml-template
@@ -0,0 +1,44 @@
+name: Test
+
+on:
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [20.x]
+    services:
+      postgres:
+        image: postgres:latest
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: password
+          POSTGRES_DB: students
+          POSTGRES_PORT: 5432
+          POSTGRES_HOST: localhost
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Node.js
+        uses: actions/setup-node@v1
+        with:
+          node-version: '20'
+      - name: Install dependencies
+        run: npm install
+      - name: Run tests
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: password
+          POSTGRES_DB: students
+          POSTGRES_HOST: localhost
+          POSTGRES_PORT: 5432
+        run: npm test
diff --git a/.gitignore b/.gitignore
index ed48a299d..bd6a178a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,7 +7,3 @@ node_modules
 
 # MacOS
 .DS_Store
-
-# env files
-*.env
-.env*
diff --git a/package-lock.json b/package-lock.json
index cd25728ae..03a0a7224 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17,7 +17,7 @@
       },
       "devDependencies": {
         "@mate-academy/eslint-config": "latest",
-        "@mate-academy/scripts": "^1.8.6",
+        "@mate-academy/scripts": "^2.1.3",
         "axios": "^1.7.2",
         "eslint": "^8.57.0",
         "eslint-plugin-jest": "^28.6.0",
@@ -1474,10 +1474,11 @@
       }
     },
     "node_modules/@mate-academy/scripts": {
-      "version": "1.8.6",
-      "resolved": "https://registry.npmjs.org/@mate-academy/scripts/-/scripts-1.8.6.tgz",
-      "integrity": "sha512-b4om/whj4G9emyi84ORE3FRZzCRwRIesr8tJHXa8EvJdOaAPDpzcJ8A0sFfMsWH9NUOVmOwkBtOXDu5eZZ00Ig==",
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/@mate-academy/scripts/-/scripts-2.1.3.tgz",
+      "integrity": "sha512-a07wHTj/1QUK2Aac5zHad+sGw4rIvcNl5lJmJpAD7OxeSbnCdyI6RXUHwXhjF5MaVo9YHrJ0xVahyERS2IIyBQ==",
       "dev": true,
+      "license": "MIT",
       "dependencies": {
         "@octokit/rest": "^17.11.2",
         "@types/get-port": "^4.2.0",
diff --git a/package.json b/package.json
index bdf079250..e7103013c 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
   },
   "devDependencies": {
     "@mate-academy/eslint-config": "latest",
-    "@mate-academy/scripts": "^1.8.6",
+    "@mate-academy/scripts": "^2.1.3",
     "axios": "^1.7.2",
     "eslint": "^8.57.0",
     "eslint-plugin-jest": "^28.6.0",
diff --git a/src/createServer.js b/src/createServer.js
index 1ea5542d6..f6d5f0bb3 100644
--- a/src/createServer.js
+++ b/src/createServer.js
@@ -1,7 +1,385 @@
 'use strict';
 
+const express = require('express');
+const { Op } = require('sequelize');
+const { models } = require('./models/models');
+
+const { User, Expense, Category } = models;
+
+const expenseInclude = [
+  {
+    model: Category,
+    as: 'category',
+    attributes: ['id', 'name'],
+    required: false,
+  },
+];
+
+const serializeExpense = (expense) => {
+  const plainExpense = expense.get({ plain: true });
+  const categoryName = plainExpense.category?.name;
+
+  delete plainExpense.categoryId;
+  delete plainExpense.category;
+
+  if (categoryName !== undefined) {
+    plainExpense.category = categoryName;
+  }
+
+  return plainExpense;
+};
+
+const getCategoryId = async ({ categoryId, category }) => {
+  if (categoryId === undefined && category === undefined) {
+    return undefined;
+  }
+
+  if (categoryId !== undefined) {
+    const categoryById = await Category.findByPk(Number(categoryId));
+
+    return categoryById ? categoryById.id : null;
+  }
+
+  if (!category) {
+    return null;
+  }
+
+  const [categoryByName] = await Category.findOrCreate({
+    where: { name: category },
+    defaults: { name: category },
+  });
+
+  return categoryByName.id;
+};
+
 const createServer = () => {
-  // your code goes here
+  const app = express();
+
+  app.use(express.json());
+
+  app.post('/users', async (req, res) => {
+    const { name } = req.body;
+
+    if (!name) {
+      res.status(400).send('Name is required');
+
+      return;
+    }
+
+    const newUser = await User.create({ name });
+
+    res.status(201).json(newUser);
+  });
+
+  app.get('/users', async (_req, res) => {
+    const users = await User.findAll();
+
+    res.json(users);
+  });
+
+  app.get('/users/:userId', async (req, res) => {
+    const userId = Number(req.params.userId);
+    const user = await User.findByPk(userId);
+
+    if (!user) {
+      res.status(404).send('User not found');
+
+      return;
+    }
+
+    res.json(user);
+  });
+
+  app.patch('/users/:userId', async (req, res) => {
+    const userId = Number(req.params.userId);
+    const user = await User.findByPk(userId);
+
+    if (!user) {
+      res.status(404).send('User not found');
+
+      return;
+    }
+
+    if (!req.body.name) {
+      res.status(400).send('Name is required');
+
+      return;
+    }
+
+    await user.update({
+      name: req.body.name,
+    });
+
+    res.json(user);
+  });
+
+  app.delete('/users/:userId', async (req, res) => {
+    const userId = Number(req.params.userId);
+    const user = await User.findByPk(userId);
+
+    if (!user) {
+      res.status(404).send('User not found');
+
+      return;
+    }
+
+    await user.destroy();
+
+    res.status(204).send();
+  });
+
+  app.post('/expenses', async (req, res) => {
+    const { userId, spentAt, title, amount, categoryId, category, note } =
+      req.body;
+
+    if (!userId || !spentAt || !title || amount === undefined) {
+      res.status(400).send('Required fields are missing');
+
+      return;
+    }
+
+    const user = await User.findByPk(Number(userId));
+
+    if (!user) {
+      res.status(400).send('User not found');
+
+      return;
+    }
+
+    const resolvedCategoryId = await getCategoryId({ categoryId, category });
+
+    if (
+      (categoryId !== undefined || category !== undefined) &&
+      !resolvedCategoryId
+    ) {
+      res.status(400).send('Category not found');
+
+      return;
+    }
+
+    const newExpense = await Expense.create({
+      userId: Number(userId),
+      spentAt,
+      title,
+      amount,
+      categoryId: resolvedCategoryId,
+      note,
+    });
+
+    const createdExpense = await Expense.findByPk(newExpense.id, {
+      include: expenseInclude,
+    });
+
+    res.status(201).json(serializeExpense(createdExpense));
+  });
+
+  app.get('/expenses', async (req, res) => {
+    const { userId, from, to, categories } = req.query;
+    const where = {};
+    const include = [...expenseInclude];
+
+    if (userId) {
+      where.userId = Number(userId);
+    }
+
+    if (from || to) {
+      where.spentAt = {};
+    }
+
+    if (from) {
+      where.spentAt[Op.gte] = new Date(from);
+    }
+
+    if (to) {
+      where.spentAt[Op.lte] = new Date(to);
+    }
+
+    if (categories) {
+      include[0] = {
+        ...include[0],
+        required: true,
+        where: {
+          name: {
+            [Op.in]: categories.split(','),
+          },
+        },
+      };
+    }
+
+    const expenses = await Expense.findAll({
+      where,
+      include,
+    });
+
+    res.json(expenses.map(serializeExpense));
+  });
+
+  app.get('/expenses/:expenseId', async (req, res) => {
+    const expenseId = Number(req.params.expenseId);
+    const expense = await Expense.findByPk(expenseId, {
+      include: expenseInclude,
+    });
+
+    if (!expense) {
+      res.status(404).send('Expense not found');
+
+      return;
+    }
+
+    res.json(serializeExpense(expense));
+  });
+
+  app.patch('/expenses/:expenseId', async (req, res) => {
+    const expenseId = Number(req.params.expenseId);
+    const expense = await Expense.findByPk(expenseId, {
+      include: expenseInclude,
+    });
+
+    if (!expense) {
+      res.status(404).send('Expense not found');
+
+      return;
+    }
+
+    const { userId, spentAt, title, amount, categoryId, category, note } =
+      req.body;
+    const updatedFields = {};
+
+    if (userId !== undefined) {
+      const user = await User.findByPk(Number(userId));
+
+      if (!user) {
+        res.status(400).send('User not found');
+
+        return;
+      }
+
+      updatedFields.userId = Number(userId);
+    }
+
+    if (spentAt !== undefined) {
+      updatedFields.spentAt = spentAt;
+    }
+
+    if (title !== undefined) {
+      updatedFields.title = title;
+    }
+
+    if (amount !== undefined) {
+      updatedFields.amount = amount;
+    }
+
+    const resolvedCategoryId = await getCategoryId({ categoryId, category });
+
+    if (categoryId !== undefined || category !== undefined) {
+      if (!resolvedCategoryId && category !== null) {
+        res.status(400).send('Category not found');
+
+        return;
+      }
+
+      updatedFields.categoryId = resolvedCategoryId;
+    }
+
+    if (note !== undefined) {
+      updatedFields.note = note;
+    }
+
+    await expense.update(updatedFields);
+
+    const updatedExpense = await Expense.findByPk(expenseId, {
+      include: expenseInclude,
+    });
+
+    res.json(serializeExpense(updatedExpense));
+  });
+
+  app.delete('/expenses/:expenseId', async (req, res) => {
+    const expenseId = Number(req.params.expenseId);
+    const expense = await Expense.findByPk(expenseId);
+
+    if (!expense) {
+      res.status(404).send('Expense not found');
+
+      return;
+    }
+
+    await expense.destroy();
+
+    res.status(204).send();
+  });
+
+  app.post('/categories', async (req, res) => {
+    const { name } = req.body;
+
+    if (!name) {
+      res.status(400).send('Name is required');
+
+      return;
+    }
+
+    const category = await Category.create({ name });
+
+    res.status(201).json(category);
+  });
+
+  app.get('/categories', async (_req, res) => {
+    const categories = await Category.findAll();
+
+    res.json(categories);
+  });
+
+  app.get('/categories/:categoryId', async (req, res) => {
+    const categoryId = Number(req.params.categoryId);
+    const category = await Category.findByPk(categoryId);
+
+    if (!category) {
+      res.status(404).send('Category not found');
+
+      return;
+    }
+
+    res.json(category);
+  });
+
+  app.patch('/categories/:categoryId', async (req, res) => {
+    const categoryId = Number(req.params.categoryId);
+    const { name } = req.body;
+    const category = await Category.findByPk(categoryId);
+
+    if (!category) {
+      res.status(404).send('Category not found');
+
+      return;
+    }
+
+    if (!name) {
+      res.status(400).send('Name is required');
+
+      return;
+    }
+
+    await category.update({ name });
+
+    res.json(category);
+  });
+
+  app.delete('/categories/:categoryId', async (req, res) => {
+    const categoryId = Number(req.params.categoryId);
+    const category = await Category.findByPk(categoryId);
+
+    if (!category) {
+      res.status(404).send('Category not found');
+
+      return;
+    }
+
+    await category.destroy();
+
+    res.status(204).send();
+  });
+
+  return app;
 };
 
 module.exports = {
diff --git a/src/db.js b/src/db.js
index 1ba3046cc..141cac7df 100644
--- a/src/db.js
+++ b/src/db.js
@@ -15,18 +15,13 @@ const {
   POSTGRES_DB,
 } = process.env;
 
-/*
-  All credentials setted to default values (exsept password - it is exapmle)
-  replace if needed with your own
-*/
-
 const sequelize = new Sequelize({
   database: POSTGRES_DB || 'postgres',
   username: POSTGRES_USER || 'postgres',
   host: POSTGRES_HOST || 'localhost',
   dialect: 'postgres',
   port: POSTGRES_PORT || 5432,
-  password: POSTGRES_PASSWORD || '123',
+  password: POSTGRES_PASSWORD,
 });
 
 module.exports = {
diff --git a/src/models/Category.model.js b/src/models/Category.model.js
new file mode 100644
index 000000000..e74bdf6d7
--- /dev/null
+++ b/src/models/Category.model.js
@@ -0,0 +1,28 @@
+'use strict';
+
+const { sequelize } = require('../db.js');
+const { DataTypes } = require('sequelize');
+
+const Category = sequelize.define(
+  'Category',
+  {
+    id: {
+      type: DataTypes.INTEGER,
+      primaryKey: true,
+      autoIncrement: true,
+    },
+    name: {
+      type: DataTypes.STRING,
+      allowNull: false,
+      unique: true,
+    },
+  },
+  {
+    tableName: 'categories',
+    timestamps: false,
+  },
+);
+
+module.exports = {
+  Category,
+};
diff --git a/src/models/Expense.model.js b/src/models/Expense.model.js
index 567e1c3e7..365404526 100644
--- a/src/models/Expense.model.js
+++ b/src/models/Expense.model.js
@@ -1,9 +1,48 @@
 'use strict';
 
 const { sequelize } = require('../db.js');
+const { DataTypes } = require('sequelize');
 
 const Expense = sequelize.define(
-  // your code goes here
+  'Expense',
+  {
+    id: {
+      type: DataTypes.INTEGER,
+      primaryKey: true,
+      autoIncrement: true,
+    },
+    userId: {
+      type: DataTypes.INTEGER,
+      allowNull: false,
+      field: 'user_id',
+    },
+    spentAt: {
+      type: DataTypes.DATE,
+      allowNull: false,
+      field: 'spent_at',
+    },
+    title: {
+      type: DataTypes.STRING,
+      allowNull: false,
+    },
+    amount: {
+      type: DataTypes.INTEGER,
+      allowNull: false,
+    },
+    categoryId: {
+      type: DataTypes.INTEGER,
+      allowNull: true,
+      field: 'category_id',
+    },
+    note: {
+      type: DataTypes.STRING,
+      allowNull: true,
+    },
+  },
+  {
+    tableName: 'expenses',
+    timestamps: false,
+  },
 );
 
 module.exports = {
diff --git a/src/models/User.model.js b/src/models/User.model.js
index 61861c9e4..30fcce4dd 100644
--- a/src/models/User.model.js
+++ b/src/models/User.model.js
@@ -1,11 +1,33 @@
 'use strict';
 
 const { sequelize } = require('../db.js');
+const { DataTypes } = require('sequelize');
 
 const User = sequelize.define(
-  // your code goes here
+  'User',
+  {
+    id: {
+      type: DataTypes.INTEGER,
+      primaryKey: true,
+      autoIncrement: true,
+    },
+    name: {
+      type: DataTypes.STRING,
+      allowNull: false,
+    },
+  },
+  {
+    tableName: 'users',
+    timestamps: false,
+  },
 );
 
+User.beforeBulkDestroy((options) => {
+  if (options.truncate) {
+    options.cascade = true;
+  }
+});
+
 module.exports = {
   User,
 };
diff --git a/src/models/models.js b/src/models/models.js
index b43b55752..66f876a16 100644
--- a/src/models/models.js
+++ b/src/models/models.js
@@ -2,10 +2,34 @@
 
 const { User } = require('./User.model');
 const { Expense } = require('./Expense.model');
+const { Category } = require('./Category.model');
+
+User.hasMany(Expense, {
+  foreignKey: 'userId',
+  as: 'expenses',
+  onDelete: 'CASCADE',
+});
+
+Category.hasMany(Expense, {
+  foreignKey: 'categoryId',
+  as: 'expenses',
+  onDelete: 'SET NULL',
+});
+
+Expense.belongsTo(User, {
+  foreignKey: 'userId',
+  as: 'user',
+});
+
+Expense.belongsTo(Category, {
+  foreignKey: 'categoryId',
+  as: 'category',
+});
 
 module.exports = {
   models: {
     User,
     Expense,
+    Category,
   },
 };