diff --git a/.eslintrc.json b/.eslintrc.json
index d9f2f558..f785763f 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,4 +1,5 @@
 {
+  "root": true,
   "extends": ["eslint:recommended", "plugin:prettier/recommended"],
   "plugins": ["import"],
   "parserOptions": {
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index c3c30e1c..66717370 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -15,10 +15,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@master
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@master
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -35,10 +35,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@master
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@master
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
diff --git a/.github/workflows/test-cron.yml b/.github/workflows/test-cron.yml
index ec1fdb11..cbfd9eee 100644
--- a/.github/workflows/test-cron.yml
+++ b/.github/workflows/test-cron.yml
@@ -10,10 +10,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v1
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -28,10 +28,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v1
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -46,10 +46,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v2
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -67,10 +67,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v1
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 43ab5c09..4a0f3b20 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,10 +8,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v2
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -26,10 +26,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v2
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -44,10 +44,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v2
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
@@ -65,10 +65,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v2
 
-      - name: Install Node v12
+      - name: Install Node v14
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Install dependencies
         run: npm ci
diff --git a/README.md b/README.md
index 10a10461..146ee1af 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ discord.js is a powerful [Node.js](https://nodejs.org) module that allows you to
 
 ## Installation
 
-**Node.js 12.0.0 or newer is required.**  
+**Node.js 14.0.0 or newer is required.**  
 Ignore any warnings about unmet peer dependencies, as they're all optional.
 
 Without voice support: `npm install discord.js`  
diff --git a/docs/general/faq.md b/docs/general/faq.md
index 6624a727..466cac1c 100644
--- a/docs/general/faq.md
+++ b/docs/general/faq.md
@@ -4,7 +4,7 @@ These questions are some of the most frequently asked.
 
 ## No matter what, I get `SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode`‽
 
-Update to Node.js 12.0.0 or newer.
+Update to Node.js 14.0.0 or newer.
 
 ## How do I get voice working?
 
diff --git a/docs/general/welcome.md b/docs/general/welcome.md
index 58d36129..0dde0486 100644
--- a/docs/general/welcome.md
+++ b/docs/general/welcome.md
@@ -33,7 +33,7 @@ discord.js is a powerful [Node.js](https://nodejs.org) module that allows you to
 
 ## Installation
 
-**Node.js 12.0.0 or newer is required.**  
+**Node.js 14.0.0 or newer is required.**  
 Ignore any warnings about unmet peer dependencies, as they're all optional.
 
 Without voice support: `npm install discord.js`  
diff --git a/package.json b/package.json
index 83bf9031..33a0c78c 100644
--- a/package.json
+++ b/package.json
@@ -80,7 +80,7 @@
     "webpack-cli": "^3.3.12"
   },
   "engines": {
-    "node": ">=12.0.0"
+    "node": ">=14.0.0"
   },
   "browser": {
     "@discordjs/opus": false,
@@ -110,9 +110,9 @@
     "src/client/voice/receiver/PacketHandler.js": false,
     "src/client/voice/receiver/Receiver.js": false,
     "src/client/voice/util/PlayInterface.js": false,
-    "src/client/voice/util/Secretbox.js": false,
     "src/client/voice/util/Silence.js": false,
-    "src/client/voice/util/VolumeInterface.js": false
+    "src/client/voice/util/VolumeInterface.js": false,
+    "src/util/Sodium.js": false
   },
   "husky": {
     "hooks": {
diff --git a/src/client/Client.js b/src/client/Client.js
index a8ec7e49..8c20286b 100644
--- a/src/client/Client.js
+++ b/src/client/Client.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const BaseClient = require('./BaseClient');
+const InteractionClient = require('./InteractionClient');
 const ActionsManager = require('./actions/ActionsManager');
 const ClientVoiceManager = require('./voice/ClientVoiceManager');
 const WebSocketManager = require('./websocket/WebSocketManager');
@@ -103,6 +104,12 @@ class Client extends BaseClient {
         ? ShardClientUtil.singleton(this, process.env.SHARDING_MANAGER_MODE)
         : null;
 
+    /**
+     * The interaction client.
+     * @type {InteractionClient}
+     */
+    this.interactionClient = new InteractionClient(options, this);
+
     /**
      * All of the {@link User} objects that have been cached at any point, mapped by their IDs
      * @type {UserManager}
@@ -166,7 +173,7 @@ class Client extends BaseClient {
 
   /**
    * All custom emojis that the client has access to, mapped by their IDs
-   * @type {GuildEmojiManager}
+   * @type {BaseGuildEmojiManager}
    * @readonly
    */
   get emojis() {
diff --git a/src/client/InteractionClient.js b/src/client/InteractionClient.js
new file mode 100644
index 00000000..631c5895
--- /dev/null
+++ b/src/client/InteractionClient.js
@@ -0,0 +1,207 @@
+'use strict';
+
+const BaseClient = require('./BaseClient');
+const ApplicationCommand = require('../structures/ApplicationCommand');
+const Interaction = require('../structures/Interaction');
+const { Events, ApplicationCommandOptionType, InteractionType, InteractionResponseType } = require('../util/Constants');
+
+let sodium;
+
+/**
+ * Interaction client is used for interactions.
+ *
+ * @example
+ * const client = new InteractionClient({
+ *   token: ABC,
+ *   publicKey: XYZ,
+ * });
+ *
+ * client.on('interactionCreate', () => {
+ *   // automatically handles long responses
+ *   if (will take a long time) {
+ *     doSomethingLong.then((d) => {
+ *       interaction.reply({
+ *         content: 'wow that took long',
+ *       });
+ *     });
+ *   } else {
+ *     interaction.reply('hi!');
+ *   }
+ * });
+ * ```
+ */
+class InteractionClient extends BaseClient {
+  /**
+   * @param {Options} options Options for the client.
+   * @param {undefined} client For internal use.
+   */
+  constructor(options, client) {
+    super(options);
+
+    Object.defineProperty(this, 'token', {
+      value: options.token,
+      writable: true,
+    });
+
+    Object.defineProperty(this, 'clientID', {
+      value: options.clientID,
+      writable: true,
+    });
+
+    Object.defineProperty(this, 'publicKey', {
+      value: options.publicKey ? Buffer.from(options.publicKey, 'hex') : undefined,
+      writable: true,
+    });
+
+    // Compat for direct usage
+    this.client = client || this;
+    this.interactionClient = this;
+  }
+
+  /**
+   * Get registered slash commands.
+   * @param {Snowflake} [guildID] Optional guild ID.
+   * @returns {Command[]}
+   */
+  async getCommands(guildID) {
+    let path = this.client.api.applications('@me');
+    if (guildID) {
+      path = path.guilds(guildID);
+    }
+    const commands = await path.commands.get();
+    return commands.map(c => new ApplicationCommand(this, c, guildID));
+  }
+
+  /**
+   * Create a command.
+   * @param {Object} command The command description.
+   * @param {Snowflake?} guildID Optional guild ID.
+   * @returns {ApplicationCommand} The created command.
+   */
+  createCommand(command, guildID) {
+    let path = this.client.api.applications('@me');
+    if (guildID) {
+      path = path.guilds(guildID);
+    }
+    const c = path.commands.post({
+      data: {
+        name: command.name,
+        description: command.description,
+        options: command.options.map(function m(o) {
+          return {
+            type: ApplicationCommandOptionType[o.type],
+            name: o.name,
+            description: o.description,
+            default: o.default,
+            required: o.required,
+            choices: o.choices,
+            options: o.options ? o.options.map(m) : undefined,
+          };
+        }),
+      },
+    });
+    return new ApplicationCommand(this, c, guildID);
+  }
+
+  handle(data) {
+    switch (data.type) {
+      case InteractionType.PING:
+        return {
+          type: InteractionResponseType.PONG,
+        };
+      case InteractionType.APPLICATION_COMMAND: {
+        let timedOut = false;
+        let resolve;
+        const directPromise = new Promise(r => {
+          resolve = r;
+          this.client.setTimeout(() => {
+            timedOut = true;
+            r({
+              type: InteractionResponseType.ACKNOWLEDGE_WITH_SOURCE,
+            });
+          }, 250);
+        });
+
+        const syncHandle = {
+          acknowledge() {
+            if (!timedOut) {
+              resolve({
+                type: InteractionResponseType.ACKNOWLEDGE_WITH_SOURCE,
+              });
+            }
+          },
+          reply(resolved) {
+            if (timedOut) {
+              return false;
+            }
+            resolve({
+              type: InteractionResponseType.CHANNEL_MESSAGE_WITH_SOURCE,
+              data: resolved.data,
+            });
+            return true;
+          },
+        };
+
+        const interaction = new Interaction(this.client, data, syncHandle);
+
+        /**
+         * Emitted when an interaction is created.
+         * @event Client#interactionCreate
+         * @param {Interaction} interaction The interaction which was created.
+         */
+        this.client.emit(Events.INTERACTION_CREATE, interaction);
+
+        return directPromise;
+      }
+      default:
+        throw new RangeError('Invalid interaction data');
+    }
+  }
+
+  /**
+   * An express-like middleware factory which can be used
+   * with webhook interactions.
+   * @returns {Function} The middleware function.
+   */
+  middleware() {
+    return async (req, res) => {
+      const timestamp = req.get('x-signature-timestamp');
+      const signature = req.get('x-signature-ed25519');
+
+      const chunks = [];
+      for await (const chunk of req) {
+        chunks.push(chunk);
+      }
+      const body = Buffer.concat(chunks);
+
+      if (sodium === undefined) {
+        sodium = require('../util/Sodium');
+      }
+      if (
+        !sodium.methods.verify(
+          Buffer.from(signature, 'hex'),
+          Buffer.concat([Buffer.from(timestamp), body]),
+          this.publicKey,
+        )
+      ) {
+        res.status(403).end();
+        return;
+      }
+
+      const data = JSON.parse(body.toString());
+
+      const result = await this.handle(data);
+      res.status(200).end(JSON.stringify(result));
+    };
+  }
+
+  async handleFromGateway(data) {
+    const result = await this.handle(data);
+
+    await this.client.api.interactions(data.id, data.token).callback.post({
+      data: result,
+    });
+  }
+}
+
+module.exports = InteractionClient;
diff --git a/src/client/actions/ActionsManager.js b/src/client/actions/ActionsManager.js
index 4055795a..31ba210c 100644
--- a/src/client/actions/ActionsManager.js
+++ b/src/client/actions/ActionsManager.js
@@ -37,6 +37,7 @@ class ActionsManager {
     this.register(require('./GuildIntegrationsUpdate'));
     this.register(require('./WebhooksUpdate'));
     this.register(require('./TypingStart'));
+    this.register(require('./InteractionCreate'));
   }
 
   register(Action) {
diff --git a/src/client/actions/InteractionCreate.js b/src/client/actions/InteractionCreate.js
new file mode 100644
index 00000000..c349a0eb
--- /dev/null
+++ b/src/client/actions/InteractionCreate.js
@@ -0,0 +1,15 @@
+'use strict';
+
+const Action = require('./Action');
+
+class InteractionCreateAction extends Action {
+  handle(data) {
+    this.client.interactionClient.handleFromGateway(data).catch(e => {
+      this.client.emit('error', e);
+    });
+
+    return {};
+  }
+}
+
+module.exports = InteractionCreateAction;
diff --git a/src/client/voice/dispatcher/StreamDispatcher.js b/src/client/voice/dispatcher/StreamDispatcher.js
index bb1c7bba..bd41d4f4 100644
--- a/src/client/voice/dispatcher/StreamDispatcher.js
+++ b/src/client/voice/dispatcher/StreamDispatcher.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const { Writable } = require('stream');
-const secretbox = require('../util/Secretbox');
+const secretbox = require('../../../util/Sodium');
 const Silence = require('../util/Silence');
 const VolumeInterface = require('../util/VolumeInterface');
 
diff --git a/src/client/voice/receiver/PacketHandler.js b/src/client/voice/receiver/PacketHandler.js
index bf1a220a..807593ff 100644
--- a/src/client/voice/receiver/PacketHandler.js
+++ b/src/client/voice/receiver/PacketHandler.js
@@ -1,8 +1,8 @@
 'use strict';
 
 const EventEmitter = require('events');
+const sodium = require('../../../util/Sodium');
 const Speaking = require('../../../util/Speaking');
-const secretbox = require('../util/Secretbox');
 const { SILENCE_FRAME } = require('../util/Silence');
 
 // The delay between packets when a user is considered to have stopped speaking
@@ -58,7 +58,7 @@ class PacketHandler extends EventEmitter {
     }
 
     // Open packet
-    let packet = secretbox.methods.open(buffer.slice(12, end), this.nonce, secret_key);
+    let packet = sodium.methods.open(buffer.slice(12, end), this.nonce, secret_key);
     if (!packet) return new Error('Failed to decrypt voice packet');
     packet = Buffer.from(packet);
 
diff --git a/src/client/websocket/WebSocketManager.js b/src/client/websocket/WebSocketManager.js
index f892985f..586c83d4 100644
--- a/src/client/websocket/WebSocketManager.js
+++ b/src/client/websocket/WebSocketManager.js
@@ -76,7 +76,7 @@ class WebSocketManager extends EventEmitter {
 
     /**
      * The current status of this WebSocketManager
-     * @type {number}
+     * @type {Status}
      */
     this.status = Status.IDLE;
 
diff --git a/src/client/websocket/handlers/INTERACTION_CREATE.js b/src/client/websocket/handlers/INTERACTION_CREATE.js
new file mode 100644
index 00000000..5bf30fcc
--- /dev/null
+++ b/src/client/websocket/handlers/INTERACTION_CREATE.js
@@ -0,0 +1,5 @@
+'use strict';
+
+module.exports = (client, packet) => {
+  client.actions.InteractionCreate.handle(packet.d);
+};
diff --git a/src/index.js b/src/index.js
index d83e1bfa..fb1a09f6 100644
--- a/src/index.js
+++ b/src/index.js
@@ -6,6 +6,7 @@ module.exports = {
   // "Root" classes (starting points)
   BaseClient: require('./client/BaseClient'),
   Client: require('./client/Client'),
+  InteractionClient: require('./client/InteractionClient'),
   Shard: require('./sharding/Shard'),
   ShardClientUtil: require('./sharding/ShardClientUtil'),
   ShardingManager: require('./sharding/ShardingManager'),
@@ -58,6 +59,7 @@ module.exports = {
 
   // Structures
   Application: require('./structures/interfaces/Application'),
+  ApplicationCommand: require('./structures/ApplicationCommand'),
   Base: require('./structures/Base'),
   Activity: require('./structures/Presence').Activity,
   APIMessage: require('./structures/APIMessage'),
@@ -80,6 +82,7 @@ module.exports = {
   GuildPreview: require('./structures/GuildPreview'),
   GuildTemplate: require('./structures/GuildTemplate'),
   Integration: require('./structures/Integration'),
+  Interaction: require('./structures/Interaction'),
   Invite: require('./structures/Invite'),
   Message: require('./structures/Message'),
   MessageAttachment: require('./structures/MessageAttachment'),
diff --git a/src/structures/APIMessage.js b/src/structures/APIMessage.js
index bd7cc610..c24c87ea 100644
--- a/src/structures/APIMessage.js
+++ b/src/structures/APIMessage.js
@@ -74,6 +74,16 @@ class APIMessage {
     return this.target instanceof Message;
   }
 
+  /**
+   * Whether or not the target is an interaction
+   * @type {boolean}
+   * @readonly
+   */
+  get isInteraction() {
+    const Interaction = require('./Interaction');
+    return this.target instanceof Interaction;
+  }
+
   /**
    * Makes the content of this message.
    * @returns {?(string|string[])}
@@ -166,6 +176,8 @@ class APIMessage {
     if (this.isMessage) {
       // eslint-disable-next-line eqeqeq
       flags = this.options.flags != null ? new MessageFlags(this.options.flags).bitfield : this.target.flags.bitfield;
+    } else if (this.isInteraction) {
+      flags = this.options.ephemeral ? MessageFlags.EPHEMERAL : undefined;
     }
 
     let allowedMentions =
diff --git a/src/structures/ApplicationCommand.js b/src/structures/ApplicationCommand.js
new file mode 100644
index 00000000..560b95a8
--- /dev/null
+++ b/src/structures/ApplicationCommand.js
@@ -0,0 +1,102 @@
+'use strict';
+
+const Base = require('./Base');
+const { ApplicationCommandOptionType } = require('../util/Constants');
+const Snowflake = require('../util/Snowflake');
+
+/**
+ * Represents an application command, see {@link InteractionClient}.
+ * @extends {Base}
+ */
+class ApplicationCommand extends Base {
+  constructor(client, data, guildID) {
+    super(client);
+
+    /**
+     * The ID of the guild this command is part of, if any.
+     * @type {Snowflake?}
+     * @readonly
+     */
+    this.guildID = guildID || null;
+
+    this._patch(data);
+  }
+
+  _patch(data) {
+    /**
+     * The ID of this command.
+     * @type {Snowflake}
+     * @readonly
+     */
+    this.id = data.id;
+
+    /**
+     * The ID of the application which owns this command.
+     * @type {Snowflake}
+     * @readonly
+     */
+    this.appplicationID = data.application_id;
+
+    /**
+     * The name of this command.
+     * @type {string}
+     * @readonly
+     */
+    this.name = data.name;
+
+    /**
+     * The description of this command.
+     * @type {string}
+     * @readonly
+     */
+    this.description = data.description;
+
+    /**
+     * The options of this command.
+     * @type {Object[]}
+     * @readonly
+     */
+    this.options = data.options.map(function m(o) {
+      return {
+        type: ApplicationCommandOptionType[o.type],
+        name: o.name,
+        description: o.description,
+        default: o.default,
+        required: o.required,
+        choices: o.choices,
+        options: o.options ? o.options.map(m) : undefined,
+      };
+    });
+  }
+
+  /**
+   * The timestamp the command was created at.
+   * @type {number}
+   * @readonly
+   */
+  get createdTimestamp() {
+    return Snowflake.deconstruct(this.id).timestamp;
+  }
+
+  /**
+   * The time the command was created at.
+   * @type {Date}
+   * @readonly
+   */
+  get createdAt() {
+    return new Date(this.createdTimestamp);
+  }
+
+  /**
+   * Delete this command.
+   */
+  async delete() {
+    let path = this.client.api.applications('@me');
+    if (this.guildID) {
+      path = path.guilds(this.guildID);
+    }
+    await path.commands(this.id).delete();
+  }
+}
+
+module.exports = ApplicationCommand;
diff --git a/src/structures/BaseGuildEmoji.js b/src/structures/BaseGuildEmoji.js
index a2007c67..09dd04f3 100644
--- a/src/structures/BaseGuildEmoji.js
+++ b/src/structures/BaseGuildEmoji.js
@@ -17,7 +17,7 @@ class BaseGuildEmoji extends Emoji {
      */
     this.guild = guild;
 
-    this.requireColons = null;
+    this.requiresColons = null;
     this.managed = null;
     this.available = null;
 
diff --git a/src/structures/Guild.js b/src/structures/Guild.js
index c9c4fe9f..524ea64c 100644
--- a/src/structures/Guild.js
+++ b/src/structures/Guild.js
@@ -1432,6 +1432,23 @@ class Guild extends Base {
       .then(() => this);
   }
 
+  /**
+   * Get the commands associated with this guild.
+   * @returns {ApplicationCommand[]} A list of commands.
+   */
+  getCommands() {
+    return this.client.interactionClient.getCommands(this.id);
+  }
+
+  /**
+   * Create a command. See {@link InteractionClient}.
+   * @param {Object} command The command description.
+   * @returns {ApplicationCommand} The created command.
+   */
+  createCommand(command) {
+    return this.client.interactionClient.createCommand(command, this.id);
+  }
+
   /**
    * Leaves the guild.
    * @returns {Promise<Guild>}
diff --git a/src/structures/Interaction.js b/src/structures/Interaction.js
new file mode 100644
index 00000000..c7e47f06
--- /dev/null
+++ b/src/structures/Interaction.js
@@ -0,0 +1,133 @@
+'use strict';
+
+const APIMessage = require('./APIMessage');
+const Base = require('./Base');
+const Snowflake = require('../util/Snowflake');
+
+/**
+ * Represents an interaction, see {@link InteractionClient}.
+ * @extends {Base}
+ */
+class Interaction extends Base {
+  constructor(client, data, syncHandle) {
+    super(client);
+    this.syncHandle = syncHandle;
+    this._patch(data);
+  }
+
+  _patch(data) {
+    /**
+     * The ID of this interaction.
+     * @type {Snowflake}
+     * @readonly
+     */
+    this.id = data.id;
+
+    /**
+     * The token of this interaction.
+     * @type {string}
+     * @readonly
+     */
+    this.token = data.token;
+
+    /**
+     * The ID of the invoked command.
+     * @type {Snowflake}
+     * @readonly
+     */
+    this.commandID = data.data.id;
+
+    /**
+     * The name of the invoked command.
+     * @type {string}
+     * @readonly
+     */
+    this.commandName = data.data.name;
+
+    /**
+     * The options passed to the command.
+     * @type {Object}
+     * @readonly
+     */
+    this.options = data.data.options;
+
+    /**
+     * The channel this interaction was sent in.
+     * @type {?Channel}
+     * @readonly
+     */
+    this.channel = this.client.channels?.cache.get(data.channel_id) || null;
+
+    /**
+     * The guild this interaction was sent in, if any.
+     * @type {?Guild}
+     * @readonly
+     */
+    this.guild = data.guild_id ? this.client.guilds?.cache.get(data.guild_id) : null;
+
+    /**
+     * If this interaction was sent in a guild, the member which sent it.
+     * @type {?Member}
+     * @readonly
+     */
+    this.member = data.member ? this.guild?.members.add(data.member, false) : null;
+  }
+
+  /**
+   * The timestamp the interaction was created at.
+   * @type {number}
+   * @readonly
+   */
+  get createdTimestamp() {
+    return Snowflake.deconstruct(this.id).timestamp;
+  }
+
+  /**
+   * The time the interaction was created at.
+   * @type {Date}
+   * @readonly
+   */
+  get createdAt() {
+    return new Date(this.createdTimestamp);
+  }
+
+  /**
+   * Acknowledge this interaction without content.
+   */
+  async acknowledge() {
+    await this.syncHandle.acknowledge();
+  }
+
+  /**
+   * Reply to this interaction.
+   * @param {(StringResolvable | APIMessage)?} content The content for the message.
+   * @param {(MessageOptions | MessageAdditions)?} options The options to provide.
+   */
+  async reply(content, options) {
+    let apiMessage;
+
+    if (content instanceof APIMessage) {
+      apiMessage = content.resolveData();
+    } else {
+      apiMessage = APIMessage.create(this, content, options).resolveData();
+      if (Array.isArray(apiMessage.data.content)) {
+        throw new Error('Message is too long');
+      }
+    }
+
+    const resolved = await apiMessage.resolveFiles();
+
+    if (!this.syncHandle.reply(resolved)) {
+      const clientID =
+        this.client.interactionClient.clientID || (await this.client.api.oauth2.applications('@me').get()).id;
+
+      await this.client.api.webhooks(clientID, this.token).post({
+        auth: false,
+        data: resolved.data,
+        files: resolved.files,
+      });
+    }
+  }
+}
+
+module.exports = Interaction;
diff --git a/src/structures/User.js b/src/structures/User.js
index d7ebe03f..2811e862 100644
--- a/src/structures/User.js
+++ b/src/structures/User.js
@@ -278,7 +278,7 @@ class User extends Base {
 
   /**
    * Fetches this user's flags.
-   * @param {boolean} [force=false] Whether to skip the cache check and request the AP
+   * @param {boolean} [force=false] Whether to skip the cache check and request the API
    * @returns {Promise<UserFlags>}
    */
   async fetchFlags(force = false) {
@@ -290,7 +290,7 @@ class User extends Base {
 
   /**
    * Fetches this user.
-   * @param {boolean} [force=false] Whether to skip the cache check and request the AP
+   * @param {boolean} [force=false] Whether to skip the cache check and request the API
    * @returns {Promise<User>}
    */
   fetch(force = false) {
diff --git a/src/structures/interfaces/Collector.js b/src/structures/interfaces/Collector.js
index 969b3d2c..e8745385 100644
--- a/src/structures/interfaces/Collector.js
+++ b/src/structures/interfaces/Collector.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const EventEmitter = require('events');
+const { TypeError } = require('../../errors');
 const Collection = require('../../util/Collection');
 const Util = require('../../util/Util');
 
@@ -74,6 +75,10 @@ class Collector extends EventEmitter {
      */
     this._idletimeout = null;
 
+    if (typeof filter !== 'function') {
+      throw new TypeError('INVALID_TYPE', 'filter', 'function');
+    }
+
     this.handleCollect = this.handleCollect.bind(this);
     this.handleDispose = this.handleDispose.bind(this);
 
diff --git a/src/util/Constants.js b/src/util/Constants.js
index 1d84a51e..0429fa12 100644
--- a/src/util/Constants.js
+++ b/src/util/Constants.js
@@ -77,14 +77,14 @@ exports.DefaultOptions = {
   /**
    * HTTP options
    * @typedef {Object} HTTPOptions
-   * @property {number} [version=7] API version to use
+   * @property {number} [version=8] API version to use
    * @property {string} [api='https://discord.com/api'] Base url of the API
    * @property {string} [cdn='https://cdn.discordapp.com'] Base url of the CDN
    * @property {string} [invite='https://discord.gg'] Base url of invites
    * @property {string} [template='https://discord.new'] Base url of templates
    */
   http: {
-    version: 7,
+    version: 8,
     api: 'https://discord.com/api',
     cdn: 'https://cdn.discordapp.com',
     invite: 'https://discord.gg',
@@ -282,6 +282,7 @@ exports.Events = {
   SHARD_READY: 'shardReady',
   SHARD_RESUME: 'shardResume',
   INVALIDATED: 'invalidated',
+  INTERACTION_CREATE: 'interactionCreate',
   RAW: 'raw',
 };
 
@@ -345,6 +346,7 @@ exports.PartialTypes = keyMirror(['USER', 'CHANNEL', 'GUILD_MEMBER', 'MESSAGE',
  * * VOICE_STATE_UPDATE
  * * VOICE_SERVER_UPDATE
  * * WEBHOOKS_UPDATE
+ * * INTERACTION_CREATE
  * @typedef {string} WSEventType
  */
 exports.WSEvents = keyMirror([
@@ -384,6 +386,7 @@ exports.WSEvents = keyMirror([
   'VOICE_STATE_UPDATE',
   'VOICE_SERVER_UPDATE',
   'WEBHOOKS_UPDATE',
+  'INTERACTION_CREATE',
 ]);
 
 /**
@@ -676,6 +679,33 @@ exports.WebhookTypes = [
   'Channel Follower',
 ];
 
+exports.ApplicationCommandOptionType = {
+  SUB_COMMAND: 1,
+  SUB_COMMAND_GROUP: 2,
+  STRING: 3,
+  INTEGER: 4,
+  BOOLEAN: 5,
+  USER: 6,
+  CHANNEL: 7,
+  ROLE: 8,
+};
+Object.entries(exports.ApplicationCommandOptionType).forEach(([k, v]) => {
+  exports.ApplicationCommandOptionType[v] = k;
+});
+
+exports.InteractionType = {
+  PING: 1,
+  APPLICATION_COMMAND: 2,
+};
+
+exports.InteractionResponseType = {
+  PONG: 1,
+  ACKNOWLEDGE: 2,
+  CHANNEL_MESSAGE: 3,
+  CHANNEL_MESSAGE_WITH_SOURCE: 4,
+  ACKNOWLEDGE_WITH_SOURCE: 5,
+};
+
 function keyMirror(arr) {
   let tmp = Object.create(null);
   for (const value of arr) tmp[value] = value;
diff --git a/src/util/MessageFlags.js b/src/util/MessageFlags.js
index 536cbd88..e693158e 100644
--- a/src/util/MessageFlags.js
+++ b/src/util/MessageFlags.js
@@ -22,6 +22,7 @@ class MessageFlags extends BitField {}
  * * `SUPPRESS_EMBEDS`
  * * `SOURCE_MESSAGE_DELETED`
  * * `URGENT`
+ * * `EPHEMERAL`
  * @type {Object}
  * @see {@link https://discord.com/developers/docs/resources/channel#message-object-message-flags}
  */
@@ -31,6 +32,7 @@ MessageFlags.FLAGS = {
   SUPPRESS_EMBEDS: 1 << 2,
   SOURCE_MESSAGE_DELETED: 1 << 3,
   URGENT: 1 << 4,
+  EPHEMERAL: 1 << 6,
 };
 
 module.exports = MessageFlags;
diff --git a/src/client/voice/util/Secretbox.js b/src/util/Sodium.js
similarity index 84%
rename from src/client/voice/util/Secretbox.js
rename to src/util/Sodium.js
index c16a4353..e19b5b9a 100644
--- a/src/client/voice/util/Secretbox.js
+++ b/src/util/Sodium.js
@@ -5,16 +5,19 @@ const libs = {
     open: sodium.api.crypto_secretbox_open_easy,
     close: sodium.api.crypto_secretbox_easy,
     random: n => sodium.randombytes_buf(n),
+    verify: sodium.api.crypto_sign_verify_detached,
   }),
   'libsodium-wrappers': sodium => ({
     open: sodium.crypto_secretbox_open_easy,
     close: sodium.crypto_secretbox_easy,
     random: n => sodium.randombytes_buf(n),
+    verify: sodium.crypto_sign_verify_detached,
   }),
   tweetnacl: tweetnacl => ({
     open: tweetnacl.secretbox.open,
     close: tweetnacl.secretbox,
     random: n => tweetnacl.randomBytes(n),
+    verify: (s, d, p) => tweetnacl.sign.detached.verify(d, s, p),
   }),
 };