diff --git a/api/middlewares/authenticate.ts b/api/middlewares/authenticate.ts
new file mode 100644
index 0000000..39fdad2
--- /dev/null
+++ b/api/middlewares/authenticate.ts
@@ -0,0 +1,28 @@
+import {IToken, Token} from "../../models/Token";
+import {IUser, User} from "../../models/User";
+import {NextFunction, Request, Response} from "express";
+
+export interface AuthenticatedRequest extends Request {
+    token: IToken
+    user: IUser
+}
+
+module.exports.authenticate = async (req: AuthenticatedRequest, res: Response, next: NextFunction) => {
+    // Get the token header
+    const authHeader = req.headers["authorization"];
+    if (!authHeader) return res.status(400).json({message: "You need to provide the 'authorization' header"});
+
+    // Validate token header
+    const splitHeader = authHeader.split(" ");
+    if (splitHeader.length !== 2) return res.status(400).json({message: "You need to provide the token in the 'authorization' header"});
+
+    // Check if the provided token is wrong
+    req.token = await Token.findOne({token: splitHeader[1]}).exec() as IToken;
+    if (req.token == null) return res.status(401).json({message: "The provided token is wrong"});
+
+    // Check if the provided user exists
+    req.user = await User.findOne({clientId: req.token.clientId}) as IUser;
+    if (req.user == null) return res.status(401).json({message: "The provided token is wrong"});
+
+    next();
+}
\ No newline at end of file