diff --git a/package-lock.json b/package-lock.json
index 4d08cfe..275ca3a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1509,6 +1509,12 @@
         "@types/node": "*"
       }
     },
+    "@types/cors": {
+      "version": "2.8.12",
+      "resolved": "https://registry.npmjs.org/@types/cors/-/cors-2.8.12.tgz",
+      "integrity": "sha512-vt+kDhq/M2ayberEtJcIN/hxXy1Pk+59g2FV/ZQceeaTyCtCucjL2Q7FXlFjtWn4n15KCr1NE2lNNFhp0lEThw==",
+      "dev": true
+    },
     "@types/event-stream": {
       "version": "3.3.34",
       "resolved": "https://registry.npmjs.org/@types/event-stream/-/event-stream-3.3.34.tgz",
@@ -1546,6 +1552,15 @@
       "integrity": "sha512-qcUXuemtEu+E5wZSJHNxUXeCZhAfXKQ41D+duX+VYPde7xyEVZci+/oXKJL13tnRs9lR2pr4fod59GT6/X1/yQ==",
       "dev": true
     },
+    "@types/jsonwebtoken": {
+      "version": "8.5.6",
+      "resolved": "https://registry.npmjs.org/@types/jsonwebtoken/-/jsonwebtoken-8.5.6.tgz",
+      "integrity": "sha512-+P3O/xC7nzVizIi5VbF34YtqSonFsdnbXBnWUCYRiKOi1f9gA4sEFvXkrGr/QVV23IbMYvcoerI7nnhDUiWXRQ==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*"
+      }
+    },
     "@types/mime": {
       "version": "1.3.2",
       "resolved": "https://registry.npmjs.org/@types/mime/-/mime-1.3.2.tgz",
@@ -1588,6 +1603,12 @@
         "@types/node": "*"
       }
     },
+    "@types/uuid": {
+      "version": "8.3.3",
+      "resolved": "https://registry.npmjs.org/@types/uuid/-/uuid-8.3.3.tgz",
+      "integrity": "sha512-0LbEEx1zxrYB3pgpd1M5lEhLcXjKJnYghvhTRgaBeUivLHMDM1TzF3IJ6hXU2+8uA4Xz+5BA63mtZo5DjVT8iA==",
+      "dev": true
+    },
     "@typescript-eslint/eslint-plugin": {
       "version": "5.1.0",
       "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-5.1.0.tgz",
@@ -2038,6 +2059,11 @@
         "node-releases": "^1.1.76"
       }
     },
+    "buffer-equal-constant-time": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/buffer-equal-constant-time/-/buffer-equal-constant-time-1.0.1.tgz",
+      "integrity": "sha1-+OcRMvf/5uAaXJaXpMbz5I1cyBk="
+    },
     "buffer-from": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.2.tgz",
@@ -2365,6 +2391,15 @@
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.3.tgz",
       "integrity": "sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ=="
     },
+    "cors": {
+      "version": "2.8.5",
+      "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
+      "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
+      "requires": {
+        "object-assign": "^4",
+        "vary": "^1"
+      }
+    },
     "cross-spawn": {
       "version": "7.0.3",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
@@ -2509,6 +2544,14 @@
       "integrity": "sha1-7gHdHKwO08vH/b6jfcCo8c4ALOI=",
       "dev": true
     },
+    "ecdsa-sig-formatter": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/ecdsa-sig-formatter/-/ecdsa-sig-formatter-1.0.11.tgz",
+      "integrity": "sha512-nagl3RYrbNv6kQkeJIpt6NJZy8twLB/2vtz6yN9Z4vRKHN4/QZJIEbqohALSgwKdnksuY3k5Addp5lg8sVoVcQ==",
+      "requires": {
+        "safe-buffer": "^5.0.1"
+      }
+    },
     "ee-first": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
@@ -3676,6 +3719,42 @@
         "minimist": "^1.2.5"
       }
     },
+    "jsonwebtoken": {
+      "version": "8.5.1",
+      "resolved": "https://registry.npmjs.org/jsonwebtoken/-/jsonwebtoken-8.5.1.tgz",
+      "integrity": "sha512-XjwVfRS6jTMsqYs0EsuJ4LGxXV14zQybNd4L2r0UvbVnSF9Af8x7p5MzbJ90Ioz/9TI41/hTCvznF/loiSzn8w==",
+      "requires": {
+        "jws": "^3.2.2",
+        "lodash.includes": "^4.3.0",
+        "lodash.isboolean": "^3.0.3",
+        "lodash.isinteger": "^4.0.4",
+        "lodash.isnumber": "^3.0.3",
+        "lodash.isplainobject": "^4.0.6",
+        "lodash.isstring": "^4.0.1",
+        "lodash.once": "^4.0.0",
+        "ms": "^2.1.1",
+        "semver": "^5.6.0"
+      }
+    },
+    "jwa": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/jwa/-/jwa-1.4.1.tgz",
+      "integrity": "sha512-qiLX/xhEEFKUAJ6FiBMbes3w9ATzyk5W7Hvzpa/SLYdxNtng+gcurvrI7TbACjIXlsJyr05/S1oUhZrc63evQA==",
+      "requires": {
+        "buffer-equal-constant-time": "1.0.1",
+        "ecdsa-sig-formatter": "1.0.11",
+        "safe-buffer": "^5.0.1"
+      }
+    },
+    "jws": {
+      "version": "3.2.2",
+      "resolved": "https://registry.npmjs.org/jws/-/jws-3.2.2.tgz",
+      "integrity": "sha512-YHlZCB6lMTllWDtSPHz/ZXTsi8S00usEV6v1tjq8tOUZzw7DpSDWVXjXDre6ed1w/pd495ODpHZYSdkRTsa0HA==",
+      "requires": {
+        "jwa": "^1.4.1",
+        "safe-buffer": "^5.0.1"
+      }
+    },
     "keyv": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/keyv/-/keyv-3.1.0.tgz",
@@ -3736,12 +3815,47 @@
       "integrity": "sha1-gteb/zCmfEAF/9XiUVMArZyk168=",
       "dev": true
     },
+    "lodash.includes": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/lodash.includes/-/lodash.includes-4.3.0.tgz",
+      "integrity": "sha1-YLuYqHy5I8aMoeUTJUgzFISfVT8="
+    },
+    "lodash.isboolean": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isboolean/-/lodash.isboolean-3.0.3.tgz",
+      "integrity": "sha1-bC4XHbKiV82WgC/UOwGyDV9YcPY="
+    },
+    "lodash.isinteger": {
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/lodash.isinteger/-/lodash.isinteger-4.0.4.tgz",
+      "integrity": "sha1-YZwK89A/iwTDH1iChAt3sRzWg0M="
+    },
+    "lodash.isnumber": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isnumber/-/lodash.isnumber-3.0.3.tgz",
+      "integrity": "sha1-POdoEMWSjQM1IwGsKHMX8RwLH/w="
+    },
+    "lodash.isplainobject": {
+      "version": "4.0.6",
+      "resolved": "https://registry.npmjs.org/lodash.isplainobject/-/lodash.isplainobject-4.0.6.tgz",
+      "integrity": "sha1-fFJqUtibRcRcxpC4gWO+BJf1UMs="
+    },
+    "lodash.isstring": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/lodash.isstring/-/lodash.isstring-4.0.1.tgz",
+      "integrity": "sha1-1SfftUVuynzJu5XV2ur4i6VKVFE="
+    },
     "lodash.merge": {
       "version": "4.6.2",
       "resolved": "https://registry.npmjs.org/lodash.merge/-/lodash.merge-4.6.2.tgz",
       "integrity": "sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==",
       "dev": true
     },
+    "lodash.once": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/lodash.once/-/lodash.once-4.1.1.tgz",
+      "integrity": "sha1-DdOXEhPHxW34gJd9UEyI+0cal6w="
+    },
     "logform": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/logform/-/logform-2.3.0.tgz",
@@ -4041,6 +4155,11 @@
       "integrity": "sha512-9UZCFRHQdNrfTpGg8+1INIg93B6zE0aXMVFkw1WFwvO4SlZywU6aLg5Of0Ap/PgcbSw4LNxvMWXMeugwMCX0AA==",
       "dev": true
     },
+    "object-assign": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
+      "integrity": "sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM="
+    },
     "object-inspect": {
       "version": "1.11.0",
       "resolved": "https://registry.npmjs.org/object-inspect/-/object-inspect-1.11.0.tgz",
diff --git a/package.json b/package.json
index 7c572a8..e48bf11 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
-    "module-4": "nodemon --exec babel-node ./src/module-3/index.ts --extensions .ts",
+    "dev": "nodemon --exec babel-node ./src/module-3/index.ts --extensions .ts",
     "lint": "eslint . --ext .ts"
   },
   "author": "",
@@ -14,12 +14,14 @@
     "@types/event-stream": "^3.3.34",
     "@types/node": "^16.10.1",
     "bunyan": "^1.8.15",
+    "cors": "^2.8.5",
     "csvtojson": "^2.0.10",
     "dotenv": "^10.0.0",
     "event-stream": "^4.0.1",
     "express": "^4.17.1",
     "express-joi-validation": "^5.0.0",
     "joi": "^17.4.2",
+    "jsonwebtoken": "^8.5.1",
     "morgan": "^1.10.0",
     "pg": "^8.7.1",
     "pg-hstore": "^2.3.4",
@@ -35,8 +37,11 @@
     "@babel/preset-env": "^7.15.6",
     "@babel/preset-typescript": "^7.15.0",
     "@types/bunyan": "^1.8.8",
+    "@types/cors": "^2.8.12",
     "@types/express": "^4.17.13",
+    "@types/jsonwebtoken": "^8.5.6",
     "@types/morgan": "^1.9.3",
+    "@types/uuid": "^8.3.3",
     "@typescript-eslint/eslint-plugin": "^5.1.0",
     "@typescript-eslint/parser": "^5.1.0",
     "babel-eslint": "^10.1.0",
diff --git a/src/module-3/controllers/auth.ts b/src/module-3/controllers/auth.ts
new file mode 100644
index 0000000..5c7cb72
--- /dev/null
+++ b/src/module-3/controllers/auth.ts
@@ -0,0 +1,55 @@
+import express, { Request, Response } from "express";
+import { createValidator } from "express-joi-validation";
+import { log, logger } from "../middlewares/loggers";
+import * as AuthService from "../services/auth";
+import { UserAuthModel } from "../types";
+import {
+  loginValidationSchema,
+  updTokenValidationSchema
+} from "./validation/auth";
+
+const validator = createValidator();
+const router = express.Router();
+
+router.post(
+  "/login",
+  [validator.body(loginValidationSchema), log(AuthService.verify)],
+  async (req: Request, res: Response) => {
+    try {
+      const { login, password }: UserAuthModel = req.body;
+      const token = (await AuthService.verify(login, password)) ?? {};
+
+      if (!token) {
+        return res.status(403).send({
+          success: false,
+          message: "Bad username / password combination. Please try again."
+        });
+      }
+
+      res.status(200).send(token);
+    } catch (e) {
+      logger.setError(e);
+      res.status(500).send(e.message);
+    }
+  }
+);
+
+router.post(
+  "/token",
+  [validator.body(updTokenValidationSchema), log(AuthService.refreshToken)],
+  async (req: Request, res: Response) => {
+    const data = req.body;
+
+    try {
+      const token = await AuthService.refreshToken(data);
+      if (!token) {
+        return res.status(404).send("Invalid request");
+      }
+      res.status(200).json(token);
+    } catch (e) {
+      logger.setError(e);
+    }
+  }
+);
+
+export default router;
diff --git a/src/module-3/controllers/groups.ts b/src/module-3/controllers/groups.ts
index a8e8ea9..c0f0a92 100644
--- a/src/module-3/controllers/groups.ts
+++ b/src/module-3/controllers/groups.ts
@@ -1,6 +1,7 @@
 import express from "express";
 import { createValidator } from "express-joi-validation";
-import { log, logger } from "../loggers";
+import { checkToken } from "../middlewares/auth";
+import { log, logger } from "../middlewares/loggers";
 import * as GroupsService from "../services/groups";
 import { Errors, GroupModel } from "../types";
 import { isNull } from "./utils";
@@ -11,7 +12,7 @@ const router = express.Router();
 
 /* Get all groups */
 
-router.get("/", log(GroupsService.findAll), async (req, res) => {
+router.get("/", [checkToken, log(GroupsService.findAll)], async (req, res) => {
   try {
     const groups = await GroupsService.findAll();
     res.status(200).send(groups);
@@ -23,7 +24,7 @@ router.get("/", log(GroupsService.findAll), async (req, res) => {
 
 /* Find group by id */
 
-router.get("/:id", log(GroupsService.find), async (req, res) => {
+router.get("/:id", [checkToken, log(GroupsService.find)], async (req, res) => {
   try {
     const id = req.params.id;
     const group = await GroupsService.find(id);
@@ -42,7 +43,11 @@ router.get("/:id", log(GroupsService.find), async (req, res) => {
 
 router.post(
   "/",
-  [log(GroupsService.create), validator.body(groupValidationSchema)],
+  [
+    log(GroupsService.create),
+    validator.body(groupValidationSchema),
+    checkToken
+  ],
   async (req, res) => {
     try {
       const body: GroupModel = req.body;
@@ -61,26 +66,34 @@ router.post(
 
 /* Delete group */
 
-router.delete("/:id", log(GroupsService.remove), async (req, res) => {
-  try {
-    const id = req.params.id;
-    const isSuccess = await GroupsService.remove(id);
-    if (isNull(isSuccess)) {
-      const err = "Something wrong";
-      logger.setError(err);
-      return res.status(404).send(err);
+router.delete(
+  "/:id",
+  [checkToken, log(GroupsService.remove)],
+  async (req, res) => {
+    try {
+      const id = req.params.id;
+      const isSuccess = await GroupsService.remove(id);
+      if (isNull(isSuccess)) {
+        const err = "Something wrong";
+        logger.setError(err);
+        return res.status(404).send(err);
+      }
+      res.redirect("/api/groups");
+    } catch (e) {
+      res.status(500).send(e.message);
     }
-    res.redirect("/api/groups");
-  } catch (e) {
-    res.status(500).send(e.message);
   }
-});
+);
 
 /* Update group */
 
 router.put(
   "/:id",
-  [log(GroupsService.update), validator.body(groupValidationSchema)],
+  [
+    log(GroupsService.update),
+    checkToken,
+    validator.body(groupValidationSchema)
+  ],
   async ({ params: { id }, body }, res) => {
     try {
       const status = await GroupsService.update(id, body);
diff --git a/src/module-3/controllers/user-groups.ts b/src/module-3/controllers/user-groups.ts
index 67ca29b..f8ff188 100644
--- a/src/module-3/controllers/user-groups.ts
+++ b/src/module-3/controllers/user-groups.ts
@@ -1,6 +1,7 @@
 import express from "express";
 import { createValidator } from "express-joi-validation";
-import { log, logger } from "../loggers";
+import { checkToken } from "../middlewares/auth";
+import { log, logger } from "../middlewares/loggers";
 import { AddUsersToGroupModel } from "../services/types";
 import * as UserGroupsService from "../services/user-groups";
 import userGroupValidationSchema from "./validation/user-groups";
@@ -10,15 +11,19 @@ const router = express.Router();
 
 /* Get user-groups list */
 
-router.get("/", log(UserGroupsService.findAll), async (req, res) => {
-  try {
-    const userGroups = await UserGroupsService.findAll();
-    res.status(200).send(userGroups);
-  } catch (e) {
-    logger.setError(e);
-    res.status(500).send(e.message);
+router.get(
+  "/",
+  [checkToken, log(UserGroupsService.findAll)],
+  async (req, res) => {
+    try {
+      const userGroups = await UserGroupsService.findAll();
+      res.status(200).send(userGroups);
+    } catch (e) {
+      logger.setError(e);
+      res.status(500).send(e.message);
+    }
   }
-});
+);
 
 /* Add user to any group by id*/
 
@@ -26,7 +31,8 @@ router.post(
   "/",
   [
     log(UserGroupsService.addUsersToGroup),
-    validator.body(userGroupValidationSchema)
+    validator.body(userGroupValidationSchema),
+    checkToken
   ],
   async (req, res) => {
     try {
diff --git a/src/module-3/controllers/users.ts b/src/module-3/controllers/users.ts
index 459d94b..ed822f5 100644
--- a/src/module-3/controllers/users.ts
+++ b/src/module-3/controllers/users.ts
@@ -1,6 +1,7 @@
 import express from "express";
 import { createValidator } from "express-joi-validation";
-import { log, logger } from "../loggers";
+import { checkToken } from "../middlewares/auth";
+import { log, logger } from "../middlewares/loggers";
 import * as UsersService from "../services/users";
 import { UserModel } from "../types";
 import { isNull } from "./utils";
@@ -11,26 +12,22 @@ const router = express.Router();
 
 /* Get users list */
 
-router.get(
-  "/",
-  log(UsersService.getAutoSuggestUsers),
-  async ({ body }, res) => {
-    try {
-      const users = await UsersService.getAutoSuggestUsers(
-        body.loginSubstring,
-        body.limit
-      );
-      res.status(200).send(users);
-    } catch (e) {
-      logger.setError(e);
-      res.status(500).send(e.message);
-    }
+router.get("/", checkToken, async ({ body }, res) => {
+  try {
+    const users = await UsersService.getAutoSuggestUsers(
+      body.loginSubstring,
+      body.limit
+    );
+    res.status(200).send(users);
+  } catch (e) {
+    logger.setError(e);
+    res.status(500).send(e.message);
   }
-);
+});
 
 /* Find user by id */
 
-router.get("/:id", log(UsersService.find), async (req, res) => {
+router.get("/:id", [checkToken, log(UsersService.find)], async (req, res) => {
   try {
     const id = req.params.id;
     const user = await UsersService.find(id);
@@ -49,7 +46,7 @@ router.get("/:id", log(UsersService.find), async (req, res) => {
 
 router.post(
   "/",
-  [log(UsersService.create), validator.body(userValidationSchema)],
+  [log(UsersService.create), checkToken, validator.body(userValidationSchema)],
   async (req, res) => {
     try {
       const body: UserModel = req.body;
@@ -68,26 +65,30 @@ router.post(
 
 /* Delete user */
 
-router.delete("/:id", log(UsersService.remove), async (req, res) => {
-  try {
-    const id = req.params.id;
-    const isSuccess = await UsersService.remove(id);
-    if (isNull(isSuccess)) {
-      const err = "User with this id is not found";
-      logger.setError(err);
-      return res.status(404).send(err);
+router.delete(
+  "/:id",
+  [checkToken, log(UsersService.remove)],
+  async (req, res) => {
+    try {
+      const id = req.params.id;
+      const isSuccess = await UsersService.remove(id);
+      if (isNull(isSuccess)) {
+        const err = "User with this id is not found";
+        logger.setError(err);
+        return res.status(404).send(err);
+      }
+      res.redirect("/api/users");
+    } catch (e) {
+      res.status(500).send(e.message);
     }
-    res.redirect("/api/users");
-  } catch (e) {
-    res.status(500).send(e.message);
   }
-});
+);
 
 /* Update user */
 
 router.put(
   "/:id",
-  [log(UsersService.update), validator.body(userValidationSchema)],
+  [log(UsersService.update), checkToken, validator.body(userValidationSchema)],
   async (req, res) => {
     try {
       const id = req.params.id;
diff --git a/src/module-3/controllers/validation/auth.ts b/src/module-3/controllers/validation/auth.ts
new file mode 100644
index 0000000..de1eb9a
--- /dev/null
+++ b/src/module-3/controllers/validation/auth.ts
@@ -0,0 +1,12 @@
+import joi from "joi";
+
+export const loginValidationSchema = joi.object().keys({
+  login: joi.string().alphanum().min(3).max(10).required(),
+  password: joi.string().alphanum().required()
+});
+
+export const updTokenValidationSchema = joi.object().keys({
+  login: joi.string().alphanum().min(3).max(10).required(),
+  password: joi.string().alphanum().required(),
+  refreshToken: joi.string().required()
+});
diff --git a/src/module-3/data-access/index.ts b/src/module-3/data-access/index.ts
index 0271528..234a793 100644
--- a/src/module-3/data-access/index.ts
+++ b/src/module-3/data-access/index.ts
@@ -9,6 +9,15 @@ if (!process.env.DB_URL) {
 
 const DB_URL = process.env.DB_URL;
 
+export const tokenList = {};
+
+export const JWT_DATA = {
+  refreshTokenSecret: process.env.JWT_REFRESH_TOKEN_SECRET,
+  accessTokenSecret: process.env.JWT_ACCESS_TOKEN_SECRET,
+  refreshTokenExp: Number(process.env.JWT_REFRESH_TOKEN_EXP),
+  accessTokenExp: Number(process.env.JWT_ACCESS_TOKEN_EXP)
+};
+
 export default new Sequelize(DB_URL, {
   pool: {
     max: 5,
diff --git a/src/module-3/index.ts b/src/module-3/index.ts
index f769679..6d12a0e 100644
--- a/src/module-3/index.ts
+++ b/src/module-3/index.ts
@@ -1,19 +1,18 @@
+import cors from "cors";
 import express from "express";
+import authRouter from "./controllers/auth";
 import groupsRouter from "./controllers/groups";
 import userGroupsRouter from "./controllers/user-groups";
 import usersRouter from "./controllers/users";
 import db from "./data-access";
-import {
-  errorLoggerMiddleware,
-  initHandlers,
-  mainLoggerMiddleware
-} from "./loggers";
+import { errorsLogger, initHandlers, mainLogger } from "./middlewares/loggers";
 
 const app = express();
 
 initHandlers();
 
-app.use(errorLoggerMiddleware);
+app.use(cors());
+app.use(errorsLogger);
 
 app.listen(3000, () =>
   db
@@ -25,7 +24,8 @@ app.listen(3000, () =>
     )
     .then(() => app.use(express.json()))
     .then(() => {
-      app.use(mainLoggerMiddleware);
+      app.use(mainLogger);
+      app.use("/api/auth", authRouter);
       app.use("/api/groups", groupsRouter);
       app.use("/api/users", usersRouter);
       app.use("/api/user-groups", userGroupsRouter);
diff --git a/src/module-3/middlewares/auth.ts b/src/module-3/middlewares/auth.ts
new file mode 100644
index 0000000..aef1abe
--- /dev/null
+++ b/src/module-3/middlewares/auth.ts
@@ -0,0 +1,21 @@
+import { NextFunction, Request, Response } from "express";
+import jwt from "jsonwebtoken";
+import { JWT_DATA } from "../data-access";
+
+export const checkToken = (req: Request, res: Response, next: NextFunction) => {
+  const token = req.headers["x-access-token"] as string;
+
+  if (!token) {
+    return res
+      .status(403)
+      .send({ success: false, message: "No token provided" });
+  }
+
+  jwt.verify(token, JWT_DATA.accessTokenSecret, (err: Error, decoded) => {
+    if (err) {
+      return res.json({ success: false, message: "Failed to auth token." });
+    }
+
+    next();
+  });
+};
diff --git a/src/module-3/loggers.ts b/src/module-3/middlewares/loggers.ts
similarity index 91%
rename from src/module-3/loggers.ts
rename to src/module-3/middlewares/loggers.ts
index 61d4b95..fd124e9 100644
--- a/src/module-3/loggers.ts
+++ b/src/module-3/middlewares/loggers.ts
@@ -48,14 +48,14 @@ const winstonLogger = winston.createLogger({
   exitOnError: false
 });
 
-export const errorLoggerMiddleware = morgan("tiny", {
+export const errorsLogger = morgan("tiny", {
   stream: {
     write: (message) => winstonLogger.error(message)
   },
   skip: (req, res) => res.statusCode !== 500
 });
 
-export const mainLoggerMiddleware = (
+export const mainLogger = (
   req: Request,
   res: Response,
   next: NextFunction
diff --git a/src/module-3/services/auth.ts b/src/module-3/services/auth.ts
new file mode 100644
index 0000000..9819cb7
--- /dev/null
+++ b/src/module-3/services/auth.ts
@@ -0,0 +1,64 @@
+import { Request } from "express";
+import jwt from "jsonwebtoken";
+import { JWT_DATA, tokenList } from "../data-access";
+import User from "../models/user";
+import { UserModel } from "../types";
+
+export const verify = async (
+  login: UserModel["login"],
+  password: UserModel["password"]
+) => {
+  const user = await User.findOne({
+    where: {
+      login,
+      password,
+      isDeleted: false
+    }
+  });
+
+  if (!user) {
+    return;
+  }
+
+  const payload = {
+    sub: user.get("id"),
+    login: user.get("login")
+  };
+
+  const token = jwt.sign(payload, JWT_DATA.accessTokenSecret, {
+    expiresIn: JWT_DATA.accessTokenExp
+  });
+
+  const refreshToken = jwt.sign(payload, JWT_DATA.refreshTokenSecret, {
+    expiresIn: JWT_DATA.refreshTokenExp
+  });
+
+  const response = {
+    token,
+    refreshToken
+  };
+
+  tokenList[refreshToken] = response;
+
+  return response;
+};
+
+export const refreshToken = async (body: Request["body"]) => {
+  if (body.refreshToken && body.refreshToken in tokenList) {
+    const payload = {
+      sub: body.id,
+      login: body.login
+    };
+    const token = jwt.sign(payload, JWT_DATA.accessTokenSecret, {
+      expiresIn: JWT_DATA.accessTokenExp
+    });
+
+    const response = { token };
+    // update the token in the list
+    tokenList[body.refreshToken].token = token;
+
+    return response;
+  }
+
+  return;
+};
diff --git a/src/module-3/types.ts b/src/module-3/types.ts
index 0a22483..a35498f 100644
--- a/src/module-3/types.ts
+++ b/src/module-3/types.ts
@@ -12,6 +12,8 @@ export interface UserModel extends BaseUser {
   age: number;
 }
 
+export type UserAuthModel = Pick<UserModel, "login" | "password">;
+
 export type Permissions =
   | "READ"
   | "WRITE"