diff --git a/src/controllers/categories.controller.js b/src/controllers/categories.controller.js
new file mode 100644
index 000000000..86669d7a0
--- /dev/null
+++ b/src/controllers/categories.controller.js
@@ -0,0 +1,23 @@
+const express = require('express');
+
+const {
+  getAllCategories,
+  getCategoryById,
+  deleteCategory,
+  createCategory,
+  updateCategory,
+} = require('../routers/categories.router.js');
+
+const categoriesRoute = express.Router();
+
+categoriesRoute.get('/', getAllCategories);
+
+categoriesRoute.get('/:id', getCategoryById);
+
+categoriesRoute.post('/', createCategory);
+
+categoriesRoute.delete('/:id', deleteCategory);
+
+categoriesRoute.patch('/:id', updateCategory);
+
+module.exports = { categoriesRoute };
diff --git a/src/controllers/expenses.controller.js b/src/controllers/expenses.controller.js
new file mode 100644
index 000000000..a584d7d27
--- /dev/null
+++ b/src/controllers/expenses.controller.js
@@ -0,0 +1,23 @@
+const express = require('express');
+
+const {
+  getAllExpenses,
+  getExpenseById,
+  deleteExpense,
+  createExpense,
+  updateExpense,
+} = require('../routers/expenses.router.js');
+
+const expensesRoute = express.Router();
+
+expensesRoute.get('/', getAllExpenses);
+
+expensesRoute.get('/:id', getExpenseById);
+
+expensesRoute.post('/', createExpense);
+
+expensesRoute.delete('/:id', deleteExpense);
+
+expensesRoute.patch('/:id', updateExpense);
+
+module.exports = { expensesRoute };
diff --git a/src/controllers/users.controller.js b/src/controllers/users.controller.js
new file mode 100644
index 000000000..64bad9a36
--- /dev/null
+++ b/src/controllers/users.controller.js
@@ -0,0 +1,23 @@
+const express = require('express');
+
+const {
+  getAllUsers,
+  getUsersById,
+  deleteUser,
+  createUser,
+  updateUser,
+} = require('../routers/users.router.js');
+
+const usersRoute = express.Router();
+
+usersRoute.get('/', getAllUsers);
+
+usersRoute.get('/:id', getUsersById);
+
+usersRoute.post('/', createUser);
+
+usersRoute.delete('/:id', deleteUser);
+
+usersRoute.patch('/:id', updateUser);
+
+module.exports = { usersRoute };
diff --git a/src/createServer.js b/src/createServer.js
index 1ea5542d6..1fe47719e 100644
--- a/src/createServer.js
+++ b/src/createServer.js
@@ -1,8 +1,25 @@
 'use strict';
 
-const createServer = () => {
-  // your code goes here
-};
+const express = require('express');
+const cors = require('cors');
+
+const { expensesRoute } = require('./controllers/expenses.controller.js');
+const { usersRoute } = require('./controllers/users.controller.js');
+const { categoriesRoute } = require('./controllers/categories.controller.js');
+
+function createServer() {
+  const app = express();
+
+  app.use(cors());
+
+  app.use(express.json());
+
+  app.use('/expenses', expensesRoute);
+  app.use('/users', usersRoute);
+  app.use('/categories', categoriesRoute);
+
+  return app;
+}
 
 module.exports = {
   createServer,
diff --git a/src/db.js b/src/db.js
index 1ba3046cc..d2b725960 100644
--- a/src/db.js
+++ b/src/db.js
@@ -26,7 +26,7 @@ const sequelize = new Sequelize({
   host: POSTGRES_HOST || 'localhost',
   dialect: 'postgres',
   port: POSTGRES_PORT || 5432,
-  password: POSTGRES_PASSWORD || '123',
+  password: POSTGRES_PASSWORD || '12345',
 });
 
 module.exports = {
diff --git a/src/models/Category.model.js b/src/models/Category.model.js
new file mode 100644
index 000000000..91e0e659c
--- /dev/null
+++ b/src/models/Category.model.js
@@ -0,0 +1,27 @@
+'use strict';
+
+const { DataTypes } = require('sequelize');
+const { sequelize } = require('../db.js');
+
+const Category = sequelize.define(
+  'Category',
+  {
+    id: {
+      type: DataTypes.INTEGER,
+      primaryKey: true,
+      autoIncrement: true,
+    },
+    name: {
+      type: DataTypes.STRING,
+      allowNull: false,
+    },
+  },
+  {
+    tableName: 'categories',
+    timestamps: false,
+  },
+);
+
+module.exports = {
+  Category,
+};
diff --git a/src/models/Expense.model.js b/src/models/Expense.model.js
index 567e1c3e7..2fbd35b8b 100644
--- a/src/models/Expense.model.js
+++ b/src/models/Expense.model.js
@@ -1,9 +1,44 @@
 'use strict';
 
+const { DataTypes } = require('sequelize');
 const { sequelize } = require('../db.js');
 
 const Expense = sequelize.define(
-  // your code goes here
+  'Expense',
+  {
+    id: {
+      type: DataTypes.INTEGER,
+      primaryKey: true,
+      autoIncrement: true,
+    },
+    userId: {
+      type: DataTypes.INTEGER,
+      allowNull: false,
+    },
+    spentAt: {
+      type: DataTypes.DATE,
+      allowNull: false,
+      defaultValue: DataTypes.NOW,
+    },
+    title: {
+      type: DataTypes.STRING,
+      allowNull: false,
+    },
+    amount: {
+      type: DataTypes.INTEGER,
+      allowNull: false,
+    },
+    category: {
+      type: DataTypes.STRING,
+    },
+    note: {
+      type: DataTypes.STRING,
+    },
+  },
+  {
+    tableName: 'expenses',
+    timestamps: false,
+  },
 );
 
 module.exports = {
diff --git a/src/models/User.model.js b/src/models/User.model.js
index 61861c9e4..98c5ade2b 100644
--- a/src/models/User.model.js
+++ b/src/models/User.model.js
@@ -1,9 +1,25 @@
 'use strict';
 
+const { DataTypes } = require('sequelize');
 const { sequelize } = require('../db.js');
 
 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,
+  },
 );
 
 module.exports = {
diff --git a/src/routers/categories.router.js b/src/routers/categories.router.js
new file mode 100644
index 000000000..4e223331c
--- /dev/null
+++ b/src/routers/categories.router.js
@@ -0,0 +1,102 @@
+const {
+  getAll,
+  getById,
+  create,
+  update,
+  remove,
+} = require('../services/categories.service.js');
+
+const getAllCategories = async (req, res) => {
+  const categories = await getAll();
+
+  res.send(categories);
+};
+
+const getCategoryById = async (req, res) => {
+  const { id } = req.params;
+
+  const idNum = Number(id);
+
+  const category = await getById(idNum);
+
+  if (!category) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.send(category);
+};
+
+const createCategory = async (req, res) => {
+  const { name } = req.body;
+
+  if (typeof name !== 'string') {
+    res.status(400).send({ message: 'Invalid field' });
+
+    return;
+  }
+
+  if (name === undefined) {
+    res.status(400).send({ message: 'Missing required field' });
+
+    return;
+  }
+
+  const category = await create({ name });
+
+  res.status(201).send(category);
+};
+
+const deleteCategory = async (req, res) => {
+  const { id } = req.params;
+
+  const idNum = Number(id);
+
+  const category = await remove(idNum);
+
+  if (!category) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.status(204).send();
+};
+
+const updateCategory = async (req, res) => {
+  const { id } = req.params;
+  const { name } = req.body;
+
+  const idNum = Number(id);
+
+  if (typeof name !== 'string') {
+    res.status(400).send({ message: 'Invalid field' });
+
+    return;
+  }
+
+  if (name === undefined) {
+    res.status(400).send({ message: 'Missing required field' });
+
+    return;
+  }
+
+  const category = await update({ id: idNum, name });
+
+  if (!category) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.send(category);
+};
+
+module.exports = {
+  getAllCategories,
+  getCategoryById,
+  createCategory,
+  deleteCategory,
+  updateCategory,
+};
diff --git a/src/routers/expenses.router.js b/src/routers/expenses.router.js
new file mode 100644
index 000000000..ba3a3d955
--- /dev/null
+++ b/src/routers/expenses.router.js
@@ -0,0 +1,134 @@
+const {
+  getAll,
+  getById,
+  create,
+  update,
+  remove,
+} = require('../services/expenses.service.js');
+
+const { getById: getByUserId } = require('../services/users.service.js');
+
+const getAllExpenses = async (req, res) => {
+  const { userId, from, to, categories } = req.query;
+
+  const expenses = await getAll({
+    userId: userId ? Number(userId) : undefined,
+    from,
+    to,
+    categories,
+  });
+
+  res.send(expenses);
+};
+
+const getExpenseById = async (req, res) => {
+  const { id } = req.params;
+
+  const expense = await getById(id);
+
+  if (!expense) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.send(expense);
+};
+
+const createExpense = async (req, res) => {
+  const { userId, spentAt, title, amount, category, note } = req.body;
+
+  if (userId == null || spentAt == null || title == null || amount == null) {
+    res.status(400).send({ message: 'Missing required field' });
+
+    return;
+  }
+
+  const user = await getByUserId(userId);
+
+  if (!user) {
+    return res.status(400).send({ message: 'User not found' });
+  }
+
+  if (typeof amount !== 'number' || Number.isNaN(new Date(spentAt).getTime())) {
+    return res.status(400).send({ message: 'Invalid field' });
+  }
+
+  const expense = await create({
+    userId,
+    spentAt,
+    title,
+    amount,
+    category,
+    note,
+  });
+
+  res.status(201).send(expense);
+};
+
+const deleteExpense = async (req, res) => {
+  const { id } = req.params;
+
+  const expense = await remove(id);
+
+  if (!expense) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.status(204).send();
+};
+
+const updateExpense = async (req, res) => {
+  const { id } = req.params;
+  const { amount, spentAt } = req.body;
+
+  const existingExpense = await getById(id);
+
+  if (!existingExpense) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  if (amount !== undefined && typeof amount !== 'number') {
+    res.status(400).send({ message: 'Invalid field' });
+
+    return;
+  }
+
+  if (spentAt !== undefined) {
+    const date = new Date(spentAt);
+
+    if (Number.isNaN(date.getTime())) {
+      res.status(400).send({ message: 'Invalid field' });
+
+      return;
+    }
+  }
+
+  const updatedData = {
+    ...existingExpense,
+    ...req.body,
+    id,
+  };
+
+  const expense = await update(updatedData);
+
+  if (!expense) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.status(200).send(expense);
+};
+
+module.exports = {
+  getAllExpenses,
+  getExpenseById,
+  deleteExpense,
+  createExpense,
+  updateExpense,
+};
diff --git a/src/routers/users.router.js b/src/routers/users.router.js
new file mode 100644
index 000000000..2e76235b3
--- /dev/null
+++ b/src/routers/users.router.js
@@ -0,0 +1,102 @@
+const {
+  getAll,
+  getById,
+  create,
+  update,
+  remove,
+} = require('../services/users.service.js');
+
+const getAllUsers = async (req, res) => {
+  const users = await getAll();
+
+  res.send(users);
+};
+
+const getUsersById = async (req, res) => {
+  const { id } = req.params;
+
+  const idNum = Number(id);
+
+  const user = await getById(idNum);
+
+  if (!user) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.send(user);
+};
+
+const createUser = async (req, res) => {
+  const { name } = req.body;
+
+  if (typeof name !== 'string') {
+    res.status(400).send({ message: 'Invalid field' });
+
+    return;
+  }
+
+  if (name === undefined) {
+    res.status(400).send({ message: 'Missing required field' });
+
+    return;
+  }
+
+  const user = await create({ name });
+
+  res.status(201).send(user);
+};
+
+const deleteUser = async (req, res) => {
+  const { id } = req.params;
+
+  const idNum = Number(id);
+
+  const user = await remove(idNum);
+
+  if (!user) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.status(204).send();
+};
+
+const updateUser = async (req, res) => {
+  const { id } = req.params;
+  const { name } = req.body;
+
+  const idNum = Number(id);
+
+  if (typeof name !== 'string') {
+    res.status(400).send({ message: 'Invalid field' });
+
+    return;
+  }
+
+  if (name === undefined) {
+    res.status(400).send({ message: 'Missing required field' });
+
+    return;
+  }
+
+  const user = await update({ id: idNum, name });
+
+  if (!user) {
+    res.status(404).send({ message: 'Not found' });
+
+    return;
+  }
+
+  res.send(user);
+};
+
+module.exports = {
+  getAllUsers,
+  getUsersById,
+  createUser,
+  deleteUser,
+  updateUser,
+};
diff --git a/src/services/categories.service.js b/src/services/categories.service.js
new file mode 100644
index 000000000..8b4597068
--- /dev/null
+++ b/src/services/categories.service.js
@@ -0,0 +1,41 @@
+const { Category } = require('../models/Category.model');
+
+const getAll = async () => {
+  const categories = await Category.findAll();
+
+  return categories;
+};
+
+const getById = async (id) => {
+  const category = await Category.findByPk(id);
+
+  return category;
+};
+
+const create = async ({ name }) => {
+  const category = await Category.create({ name });
+
+  return category;
+};
+
+const remove = async (id) => {
+  const deleted = await Category.destroy({ where: { id } });
+
+  return deleted;
+};
+
+const update = async ({ id, name }) => {
+  await Category.update({ name }, { where: { id } });
+
+  const category = await getById(id);
+
+  return category;
+};
+
+module.exports = {
+  getAll,
+  getById,
+  create,
+  remove,
+  update,
+};
diff --git a/src/services/expenses.service.js b/src/services/expenses.service.js
new file mode 100644
index 000000000..44ed0947e
--- /dev/null
+++ b/src/services/expenses.service.js
@@ -0,0 +1,71 @@
+/* eslint-disable function-paren-newline */
+const { Op } = require('sequelize');
+const { Expense } = require('../models/Expense.model');
+
+const getAll = async (filters = {}) => {
+  const { userId, from, to, categories } = filters;
+
+  const where = {};
+
+  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) {
+    where.category = categories;
+  }
+
+  const expenses = await Expense.findAll({ where });
+
+  return expenses;
+};
+
+const getById = async (id) => {
+  const expense = await Expense.findByPk(id);
+
+  return expense;
+};
+
+const create = async (data) => {
+  const expense = await Expense.create(data);
+
+  return expense;
+};
+
+const remove = async (id) => {
+  const deleted = await Expense.destroy({ where: { id } });
+
+  return deleted;
+};
+
+const update = async ({ id, ...updateData }) => {
+  const [updatedRows] = await Expense.update(updateData, { where: { id } });
+
+  if (updatedRows === 0) {
+    return null;
+  }
+
+  const expense = await Expense.findByPk(id);
+
+  return expense;
+};
+
+module.exports = {
+  getAll,
+  getById,
+  create,
+  remove,
+  update,
+};
diff --git a/src/services/users.service.js b/src/services/users.service.js
new file mode 100644
index 000000000..01db9d96d
--- /dev/null
+++ b/src/services/users.service.js
@@ -0,0 +1,41 @@
+const { User } = require('../models/User.model');
+
+const getAll = async () => {
+  const users = await User.findAll();
+
+  return users;
+};
+
+const getById = async (id) => {
+  const user = await User.findByPk(id);
+
+  return user;
+};
+
+const create = async ({ name }) => {
+  const user = await User.create({ name });
+
+  return user;
+};
+
+const remove = async (id) => {
+  const deleted = await User.destroy({ where: { id } });
+
+  return deleted;
+};
+
+const update = async ({ id, name }) => {
+  await User.update({ name }, { where: { id } });
+
+  const user = await getById(id);
+
+  return user;
+};
+
+module.exports = {
+  getAll,
+  getById,
+  create,
+  remove,
+  update,
+};