diff --git a/app.js b/app.js
index 40ddc7d..2210545 100644
--- a/app.js
+++ b/app.js
@@ -3,29 +3,22 @@ import express from 'express';
 import {
   InteractionType,
   InteractionResponseType,
-  InteractionResponseFlags,
-  MessageComponentTypes,
-  ButtonStyleTypes,
+  verifyKeyMiddleware,
 } from 'discord-interactions';
-import { VerifyDiscordRequest, getRandomEmoji, DiscordRequest } from './utils.js';
-import { getShuffledOptions, getResult } from './game.js';
+import { getRandomEmoji } from './utils.js';
 
 // Create an express app
 const app = express();
 // Get port, or default to 3000
 const PORT = process.env.PORT || 3000;
-// Parse request body and verifies incoming requests using discord-interactions package
-app.use(express.json({ verify: VerifyDiscordRequest(process.env.PUBLIC_KEY) }));
-
-// Store for in-progress games. In production, you'd want to use a DB
-const activeGames = {};
 
 /**
  * Interactions endpoint URL where Discord will send HTTP requests
+ * Parse request body and verifies incoming requests using discord-interactions package
  */
-app.post('/interactions', async function (req, res) {
+app.post('/interactions', verifyKeyMiddleware(process.env.PUBLIC_KEY), async function (req, res) {
   // Interaction type and data
-  const { type, id, data } = req.body;
+  const { type, data } = req.body;
 
   /**
    * Handle verification requests
@@ -48,11 +41,17 @@ app.post('/interactions', async function (req, res) {
         type: InteractionResponseType.CHANNEL_MESSAGE_WITH_SOURCE,
         data: {
           // Fetches a random emoji to send from a helper function
-          content: 'hello world ' + getRandomEmoji(),
+          content: `hello world ${getRandomEmoji()}`,
         },
       });
     }
+
+    console.error(`unknown command: ${name}`);
+    return res.status(400).json({ error: 'unknown command' });
   }
+
+  console.error('unknown interaction type', type);
+  return res.status(400).json({ error: 'unknown interaction type' });
 });
 
 app.listen(PORT, () => {
diff --git a/commands.js b/commands.js
index 63e496c..d282e56 100644
--- a/commands.js
+++ b/commands.js
@@ -42,4 +42,4 @@ const CHALLENGE_COMMAND = {
 
 const ALL_COMMANDS = [TEST_COMMAND, CHALLENGE_COMMAND];
 
-InstallGlobalCommands(process.env.APP_ID, ALL_COMMANDS);
\ No newline at end of file
+InstallGlobalCommands(process.env.APP_ID, ALL_COMMANDS);
diff --git a/examples/app.js b/examples/app.js
index 19eaa61..9b8ac13 100644
--- a/examples/app.js
+++ b/examples/app.js
@@ -6,24 +6,24 @@ import {
   InteractionResponseFlags,
   MessageComponentTypes,
   ButtonStyleTypes,
+  verifyKeyMiddleware,
 } from 'discord-interactions';
-import { VerifyDiscordRequest, getRandomEmoji, DiscordRequest } from './utils.js';
+import { getRandomEmoji, DiscordRequest } from './utils.js';
 import { getShuffledOptions, getResult } from './game.js';
 
 // Create an express app
 const app = express();
 // Get port, or default to 3000
 const PORT = process.env.PORT || 3000;
-// Parse request body and verifies incoming requests using discord-interactions package
-app.use(express.json({ verify: VerifyDiscordRequest(process.env.PUBLIC_KEY) }));
 
 // Store for in-progress games. In production, you'd want to use a DB
 const activeGames = {};
 
 /**
  * Interactions endpoint URL where Discord will send HTTP requests
+ * Parse request body and verifies incoming requests using discord-interactions package
  */
-app.post('/interactions', async function (req, res) {
+app.post('/interactions', verifyKeyMiddleware(process.env.PUBLIC_KEY), async function (req, res) {
   // Interaction type and data
   const { type, id, data } = req.body;
 
@@ -48,10 +48,11 @@ app.post('/interactions', async function (req, res) {
         type: InteractionResponseType.CHANNEL_MESSAGE_WITH_SOURCE,
         data: {
           // Fetches a random emoji to send from a helper function
-          content: 'hello world ' + getRandomEmoji(),
+          content: `hello world ${getRandomEmoji()}`,
         },
       });
     }
+
     // "challenge" command
     if (name === 'challenge' && id) {
       const userId = req.body.member.user.id;
@@ -86,6 +87,9 @@ app.post('/interactions', async function (req, res) {
         },
       });
     }
+
+    console.error(`unknown command: ${name}`);
+    return res.status(400).json({ error: 'unknown command' });
   }
 
   /**
@@ -167,6 +171,9 @@ app.post('/interactions', async function (req, res) {
       }
     }
   }
+
+  console.error('unknown interaction type', type);
+  return res.status(400).json({ error: 'unknown interaction type' });
 });
 
 app.listen(PORT, () => {
diff --git a/examples/button.js b/examples/button.js
index acb453b..1dc8ed9 100644
--- a/examples/button.js
+++ b/examples/button.js
@@ -5,14 +5,13 @@ import {
   InteractionResponseType,
   MessageComponentTypes,
   ButtonStyleTypes,
+  verifyKeyMiddleware,
 } from 'discord-interactions';
-import { VerifyDiscordRequest } from '../utils.js';
 
 // Create and configure express app
 const app = express();
-app.use(express.json({ verify: VerifyDiscordRequest(process.env.PUBLIC_KEY) }));
 
-app.post('/interactions', function (req, res) {
+app.post('/interactions', verifyKeyMiddleware(process.env.PUBLIC_KEY), function (req, res) {
   // Interaction type and data
   const { type, data } = req.body;
   /**
diff --git a/examples/command.js b/examples/command.js
index 8d6552c..5aabb5a 100644
--- a/examples/command.js
+++ b/examples/command.js
@@ -1,13 +1,12 @@
 import 'dotenv/config';
 import express from 'express';
-import { InteractionType, InteractionResponseType } from 'discord-interactions';
-import { VerifyDiscordRequest, DiscordRequest } from '../utils.js';
+import { InteractionType, InteractionResponseType, verifyKeyMiddleware } from 'discord-interactions';
+import { DiscordRequest } from '../utils.js';
 
 // Create and configure express app
 const app = express();
-app.use(express.json({ verify: VerifyDiscordRequest(process.env.PUBLIC_KEY) }));
 
-app.post('/interactions', function (req, res) {
+app.post('/interactions', verifyKeyMiddleware(process.env.PUBLIC_KEY), function (req, res) {
   // Interaction type and data
   const { type, data } = req.body;
   /**
diff --git a/examples/modal.js b/examples/modal.js
index bb3da16..76bba3a 100644
--- a/examples/modal.js
+++ b/examples/modal.js
@@ -4,14 +4,13 @@ import {
   InteractionType,
   InteractionResponseType,
   MessageComponentTypes,
+  verifyKeyMiddleware,
 } from 'discord-interactions';
-import { VerifyDiscordRequest } from '../utils.js';
 
 // Create and configure express app
 const app = express();
-app.use(express.json({ verify: VerifyDiscordRequest(process.env.PUBLIC_KEY) }));
 
-app.post('/interactions', function (req, res) {
+app.post('/interactions', verifyKeyMiddleware(process.env.PUBLIC_KEY), function (req, res) {
   // Interaction type and data
   const { type, data } = req.body;
   /**
diff --git a/examples/selectMenu.js b/examples/selectMenu.js
index bbe12f3..1420f3e 100644
--- a/examples/selectMenu.js
+++ b/examples/selectMenu.js
@@ -4,14 +4,13 @@ import {
   InteractionType,
   InteractionResponseType,
   MessageComponentTypes,
+  verifyKeyMiddleware,
 } from 'discord-interactions';
-import { VerifyDiscordRequest } from '../utils.js';
 
 // Create and configure express app
 const app = express();
-app.use(express.json({ verify: VerifyDiscordRequest(process.env.PUBLIC_KEY) }));
 
-app.post('/interactions', function (req, res) {
+app.post('/interactions', verifyKeyMiddleware(process.env.PUBLIC_KEY), function (req, res) {
   // Interaction type and data
   const { type, data } = req.body;
   /**
diff --git a/package.json b/package.json
index 72fbc75..035a2f2 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
   "author": "Shay DeWael",
   "license": "MIT",
   "dependencies": {
-    "discord-interactions": "^3.2.0",
+    "discord-interactions": "^4.0.0",
     "dotenv": "^16.0.3",
     "express": "^4.18.2"
   },
diff --git a/utils.js b/utils.js
index fbc7248..506aea6 100644
--- a/utils.js
+++ b/utils.js
@@ -1,18 +1,4 @@
 import 'dotenv/config';
-import { verifyKey } from 'discord-interactions';
-
-export function VerifyDiscordRequest(clientKey) {
-  return function (req, res, buf, encoding) {
-    const signature = req.get('X-Signature-Ed25519');
-    const timestamp = req.get('X-Signature-Timestamp');
-
-    const isValidRequest = verifyKey(buf, signature, timestamp, clientKey);
-    if (!isValidRequest) {
-      res.status(401).send('Bad request signature');
-      throw new Error('Bad request signature');
-    }
-  };
-}
 
 export async function DiscordRequest(endpoint, options) {
   // append endpoint to root API URL