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Nir
Nir

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Writing a music command for your discord.js bot (Updated March 2020)

Edit Nov 20: This guide is outdated because the play command code changes all the time. I recommend cloning my bot which is on GitHub if you're looking for a music bot with features like saved playlists

If you need a guide on how to set up a bot, please read this

Discord is a popular voice and chat app for gamers and non-gamers who use it to communicate with their friends without paying for a voice server like before.

Almost every big server has a Discord bot, which can be used for managing it, administrative commands like ban and kick, gifs and playing music. So why pay for a music bot when you can create one for free?

No time or energy to read this guide? Just clone my music bot from Github, follow the Prerequisites section, hit npm install and you'll have a working music bot!

This guide assumes you have a basic Discord bot that uses Commando already set up. If the bot does not use discord.js-commando, I highly recommend you to read this guide as Commando makes your life so much easier, and it's required for this guide.

The code for the music command is available here.

Prerequisites

Make sure ffmpeg, python 2.7, and Node(v12 atleast!) are installed.
Obtain a Youtube API key here.

Installing packages

Let's install the packages we're going to work with:
npm:

npm install discordjs/discord.js discordjs/Commando ffmpeg-static node-opus simple-youtube-api ytdl-core

yarn:

yarn add discordjs/discord.js discordjs/Commando ffmpeg-static node-opus simple-youtube-api ytdl-core@latest

Index.js (your main file)

Before we get to play.js, we need to extend the 'Guild' class so we could add a property that will hold our song queue. That will allow the bot to play music at multiple servers at a time.
To do that we'll import 'Structures' at the top of index.js, and use it to extend the 'Guild' class:

// your index.js should look similar to this:
const { CommandoClient } = require('discord.js-commando');
const { Structures } = require('discord.js');
const path = require('path');
const { prefix, token } = require('./config.json');
// It's vital this is before the initiation of the client
Structures.extend('Guild', Guild => {
  class MusicGuild extends Guild {
    constructor(client, data) {
      super(client, data);
      this.musicData = {
        queue: [],
        isPlaying: false,
        volume: 1,
        songDispatcher: null
      };
    }
  }
  return MusicGuild;
});
const client = new CommandoClient({
  commandPrefix: prefix,
  owner: 'your-discord-user-id',
  unknownCommandResponse: false
});

client.registry
  .registerDefaultTypes()
  .registerGroups([
    ['music', 'Music Command Group']
  ])
  .registerDefaultGroups()
  .registerDefaultCommands()
  .registerCommandsIn(path.join(__dirname, 'commands'));

client.once('ready', () => {
  console.log('Ready!');
});

client.login(token);

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play.js

In your 'commands' folder, create a folder named music and inside it create play.js.
We'll start with importing packages and our Youtube API key:

const { Command } = require('discord.js-commando');
const { MessageEmbed } = require('discord.js');
const Youtube = require('simple-youtube-api');
const ytdl = require('ytdl-core');
const { youtubeAPI } = require('../../config.json');
const youtube = new Youtube(youtubeAPI);
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Next we'll declare the 'PlayCommand' class which extends 'Command':

module.exports = class PlayCommand extends Command {
  constructor(client) {
    super(client, {
      name: 'play', 
      memberName: 'play',
      group: 'music', // this means the folder the file is inside
      description: 'Play any song or playlist from youtube',
      guildOnly: true, // make this command available only in servers not dm's
      clientPermissions: ['SPEAK', 'CONNECT'],
      args: [
        {
          key: 'query', // here we name the variable that will hold the input
          prompt: 'What song would you like to listen to?', // send this msg if
          // the user hasn't provided any arg or if the arg was not a string
          type: 'string',
          validate: query => query.length > 0 && query.length < 200 
        }
      ]
    });
  }
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Every command starts with the run method(the code you want the bot to run when the command is used):

  async run(message, { query }) {
    // don't let users run this command if they are not in a voice channel
    var voiceChannel = message.member.voice.channel;
    if (!voiceChannel) return message.say('Join a channel and try again');
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Users have 3 options when running this command:

  1. Run it with a song name
  2. Run it with a Youtube URL(any kind of URL)
  3. Run it with a Youtube playlist URL

For example:

!play Darude Sandstorm
!play https://www.youtube.com/watch?v=y6120QOlsfU (and other url kinds)
!play https://www.youtube.com/playlist?list=PLuUrokoVSxlfUJuJB_D8j_wsFR4exaEmy
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In order to do that we will write an if statement that checks against regex for any type of a Youtube URL. If the input matches the regex, we will apply different logic than the one we will apply on queries by song names.

First of all check if query is a playlist URL:

    if (
      query.match(
        /^(?!.*\?.*\bv=)https:\/\/www\.youtube\.com\/.*\?.*\blist=.*$/
      )
    ) {
      try {
        const playlist = await youtube.getPlaylist(query); // get playlist data 
        const videosObj = await playlist.getVideos(); // songs data object
        //const videos = Object.entries(videosObj); // turn the object to array
        // iterate through the videos array and make a song object out of each vid
        for (let i = 0; i < videosObj.length; i++) { 
          const video = await videosObj[i].fetch();

          const url = `https://www.youtube.com/watch?v=${video.raw.id}`;
          const title = video.raw.snippet.title;
          let duration = this.formatDuration(video.duration);
          const thumbnail = video.thumbnails.high.url;
          if (duration == '00:00') duration = 'Live Stream';
          const song = {
            url,
            title,
            duration,
            thumbnail,
            voiceChannel
          };

          message.guild.musicData.queue.push(song); // if you remember, the queue lives in the guild object so each server has its own queue

        }
        if (message.guild.musicData.isPlaying == false) { // if nothing is playing
          message.guild.musicData.isPlaying = true;
          return this.playSong(message.guild.musicData.queue, message); // play the playlist
        } else if (message.guild.musicData.isPlaying == true) { // if something is already playing
          return message.say(
            `Playlist - :musical_note:  ${playlist.title} :musical_note: has been added to queue`
          );
        }
      } catch (err) {
        console.error(err);
        return message.say('Playlist is either private or it does not exist');
      }
    }
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Youtube URL regex:

    if (query.match(/^(http(s)?:\/\/)?((w){3}.)?youtu(be|.be)?(\.com)?\/.+/)) {
      const url = query; // temp variable
      try {
        query = query
          .replace(/(>|<)/gi, '')
          .split(/(vi\/|v=|\/v\/|youtu\.be\/|\/embed\/)/);
        const id = query[2].split(/[^0-9a-z_\-]/i)[0];
        const video = await youtube.getVideoByID(id);
        const title = video.title;
        let duration = this.formatDuration(video.duration);
        const thumbnail = video.thumbnails.high.url;
        if (duration == '00:00') duration = 'Live Stream';
        const song = {
          url,
          title,
          duration,
          thumbnail,
          voiceChannel
        };
        message.guild.musicData.queue.push(song);
        if (
          message.guild.musicData.isPlaying == false ||
          typeof message.guild.musicData.isPlaying == 'undefined'
        ) {
          message.guild.musicData.isPlaying = true;
          return this.playSong(message.guild.musicData.queue, message);
        } else if (message.guild.musicData.isPlaying == true) {
          return message.say(`${song.title} added to queue`);
        }
      } catch (err) {
        console.error(err);
        return message.say('Something went wrong, please try again later');
      }
    }

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If the user has entered a song name as an argument:

    try {
      // search for the song and get 5 results back
      const videos = await youtube.searchVideos(query, 5);
      if (videos.length < 5) {
        return message.say(
          `I had some trouble finding what you were looking for, please try again or be more specific`
        );
      }
      const vidNameArr = [];
      // create an array that contains the result titles
      for (let i = 0; i < videos.length; i++) {
        vidNameArr.push(`${i + 1}: ${videos[i].title}`);
      }
      vidNameArr.push('exit'); // push 'exit' string as it will be an option
      // create and display an embed which will present the user the 5 results
      // so he can choose his desired result
      const embed = new MessageEmbed()
        .setColor('#e9f931')
        .setTitle('Choose a song by commenting a number between 1 and 5')
        .addField('Song 1', vidNameArr[0])
        .addField('Song 2', vidNameArr[1])
        .addField('Song 3', vidNameArr[2])
        .addField('Song 4', vidNameArr[3])
        .addField('Song 5', vidNameArr[4])
        .addField('Exit', 'exit'); // user can reply with 'exit' if none matches
      var songEmbed = await message.say({ embed });
      try {
        // wait 1 minute for the user's response
        var response = await message.channel.awaitMessages(
          msg => (msg.content > 0 && msg.content < 6) || msg.content === 'exit',
          {
            max: 1,
            maxProcessed: 1,
            time: 60000,
            errors: ['time']
          }
        );
        // assign videoIndex to user's response
        var videoIndex = parseInt(response.first().content);
      } catch (err) {
        console.error(err);
        songEmbed.delete();
        return message.say(
          'Please try again and enter a number between 1 and 5 or exit'
        );
      }
      // if the user responded with 'exit', cancel the command
      if (response.first().content === 'exit') return songEmbed.delete();
      try {
        // get video data from the API
        var video = await youtube.getVideoByID(videos[videoIndex - 1].id);
      } catch (err) {
        console.error(err);
        songEmbed.delete();
        return message.say(
          'An error has occured when trying to get the video ID from youtube'
        );
      }
      const url = `https://www.youtube.com/watch?v=${video.raw.id}`;
      const title = video.title;
      let duration = this.formatDuration(video.duration);
      const thumbnail = video.thumbnails.high.url;
        if (duration == '00:00') duration = 'Live Stream';
        const song = {
          url,
          title,
          duration,
          thumbnail,
          voiceChannel
        };

        message.guild.musicData.queue.push(song);

        if (message.guild.musicData.isPlaying == false) {
          message.guild.musicData.isPlaying = true;
          songEmbed.delete(); // delete the selection embed
          this.playSong(message.guild.musicData.queue, message);
        } else if (message.guild.musicData.isPlaying == true) {
          songEmbed.delete();
          // add the song to queue if one is already playing
          return message.say(`${song.title} added to queue`);
        }
    } catch (err) {
      // if something went wrong when calling the api:
      console.error(err);
      if (songEmbed) {
        songEmbed.delete();
      }
      return message.say(
        'Something went wrong with searching the video you requested :('
      );
    }
  }
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So what's that playSong function we called multiple times above? This function takes the queue and the message object as arguments. When called, it tells the bot to join the user's channel and start playing music!

// this is inside the PlayCommand class
  playSong(queue, message) {
    let voiceChannel;
    queue[0].voiceChannel
      .join() // join the user's voice channel
      .then(connection => {
        const dispatcher = connection
          .play(
            ytdl(queue[0].url, { // pass the url to .ytdl()
              quality: 'highestaudio',
              // download part of the song before playing it
              // helps reduces stuttering
              highWaterMark: 1024 * 1024 * 10
            })
          )
          .on('start', () => {
            // the following line is essential to other commands like skip
            message.guild.musicData.songDispatcher = dispatcher;
            dispatcher.setVolume(message.guild.musicData.volume);
            voiceChannel = queue[0].voiceChannel;
            // display the current playing song as a nice little embed
            const videoEmbed = new MessageEmbed()
              .setThumbnail(queue[0].thumbnail) // song thumbnail
              .setColor('#e9f931')
              .addField('Now Playing:', queue[0].title)
              .addField('Duration:', queue[0].duration);
            // also display next song title, if there is one in queue
            if (queue[1]) videoEmbed.addField('Next Song:', queue[1].title);
            message.say(videoEmbed); // send the embed to chat
            return queue.shift(); //  dequeue the song
          })
          .on('finish', () => { // this event fires when the song has ended
            if (queue.length >= 1) { // if there are more songs in queue
              return this.playSong(queue, message); // continue playing
            } else { // else if there are no more songs in queue
              message.guild.musicData.isPlaying = false;
              return voiceChannel.leave(); // leave the voice channel
            }
          })
          .on('error', e => {
            message.say('Cannot play song');
            message.guild.musicData.queue.length = 0;
            message.guild.musicData.isPlaying = false;
            message.guild.musicData.nowPlaying = null;
            console.error(e);
            return voiceChannel.leave();
          });
      })
      .catch(e => {
        console.error(e);
        return voiceChannel.leave();
      });
  }
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formatDuration function:

  formatDuration(durationObj) {
    const duration = `${durationObj.hours ? durationObj.hours + ':' : ''}${
      durationObj.minutes ? durationObj.minutes : '00'
    }:${
      durationObj.seconds < 10
        ? '0' + durationObj.seconds
        : durationObj.seconds
        ? durationObj.seconds
        : '00'
    }`;
    return duration;
  }
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That's it!

You can check out other music commands on the bot's repo

If you're running into issues, either comment down below or open an issue in the bot's GitHub repository.

I've also written a guide on writing a music quiz(trivia) command, you can check it out here

Top comments (79)

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syariefhdyttt profile image
Press F

Hello Nir, I got a problem at "Something went wrong with searching the video you requested :("

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galnir profile image
Nir Author

Did you generate an API key from youtube? And did you clone my repo or copy code?

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syariefhdyttt profile image
Press F

I play the song and the bot suddenly exits the voice channel and says "Cannot play song"

Thread Thread
 
syariefhdyttt profile image
Press F • Edited on

can't play playlist and bots don't join on Voice Channel
thepracticaldev.s3.amazonaws.com/i...

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galnir profile image
Nir Author

So you did something wrong, did you generate an API key from youtube?

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syariefhdyttt profile image
Press F

yes i generated API key from youtube

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galnir profile image
Nir Author

Did you install everything I listed? Git, ffmpeg etc

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syariefhdyttt profile image
Press F

I installed everything in your package.json, and I didn't change it at all

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galnir profile image
Nir Author • Edited on

I mean git, ffmpeg and python 2.7
It's in the prerequisites

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syariefhdyttt profile image
Press F

I have not installed ffmpeg and python2.7 on my computer, and I only install git

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syariefhdyttt profile image
Press F

What should I do after installing ffmpeg, python 2.7 and git?

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galnir profile image
Nir Author

You need to install them all, doesn't matter in which order

Thread Thread
 
syariefhdyttt profile image
Press F

I will try if there is a problem I will call you back, Thank you for the help.

Thread Thread
 
syariefhdyttt profile image
Press F

hello Nir, now the problem is here and I try to install node-opus in visual studio which is always error

thepracticaldev.s3.amazonaws.com/i...

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himeskitten profile image
Hime's Kitten • Edited on

Hello Nir
Having error
TypeError: Cannot read property 'isTriviaRunning' of undefined

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galnir profile image
Nir Author

Did you extend the Guild class in index.js?

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zelphy profile image
Zelphy

I seem to have an issue with extend for the guild class line.
"Structures.extend('8', Guild => {
^

TypeError: Cannot read property 'extend' of undefined"

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galnir profile image
Nir Author

Did you import Structures like I did above?

const { Structures } = require('discord.js');

Thread Thread
 
zelphy profile image
Zelphy

Ya, It's in line 2, But when I 'node .' it still doesn't run due to the error

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galnir profile image
Nir Author

Did you install the master branch of discord.js?

npm install discord.js#master

Thread Thread
 
zelphy profile image
Zelphy

I tried to but it says that the '#' is an invalid character or smth

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galnir profile image
Nir Author • Edited on

Sorry, it's

npm install discordjs/discord.js

And you need git in order for this to work

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syariefhdyttt profile image
Press F

hello nir,
I want to ask what is the purpose of git? and how to install it. sorry i am a beginner

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boldsen profile image
Boldsen

I get this error when using a link: 'No filter selected. Expected one of: idParam, myRated, chart, id'

Works fine when using the search function, only happens with links

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galnir profile image
Nir Author

What link did you try?

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boldsen profile image
Boldsen

any youtube link, when you do !play it gives this error. But not if you just do !play

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galnir profile image
Nir Author • Edited on

This error is on your end, it's a youtube API error. I'll try to figure out why you're getting it

Did you modify any code? Also check if your dependencies are the same version as the repo's

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boldsen profile image
Boldsen

Didn't modify anything no, what do you mean with repo?

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galnir profile image
Nir Author

Repository. Compare your package.json with the package.json on my repo: github.com/galnir/Master-Bot

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boldsen profile image
Boldsen

my ytdl-core is 0.29.7 instead of 0.29.5 but youtube api and discord js + commando are the same

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boldsen profile image
Boldsen

Found the issue, was missing a / or \ somewhere in the query .split

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moritzruth profile image
Moritz Ruth

Great article!

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thiccswwss profile image
thiccswwss • Edited on

Hey, everything seems to be working, but as soon as the bot joins the vc, it automatically leaves

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galnir profile image
Nir Author

Yeah there's an issue now with ytdl-core/YouTube

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thiccswwss profile image
thiccswwss

Is there any way to get around the issue, or is it like that until youtube fixes it?

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galnir profile image
Nir Author

Try removing line 252 in play.js
If that solves it tell me, not near a pc atm

Thread Thread
 
thiccswwss profile image
thiccswwss

I deleted the line, there seems to still be an issue, is this the right bit of code?
quality: 'highestaudio',

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galnir profile image
Nir Author

Yeah so there's an issue with ytdl, I just saw more ppl reporting it

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galnir profile image
Nir Author • Edited on

Update
Hey, updating ytdl-core to the latest version solves that error.

npm install ytdl-core@latest

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gameskedley profile image
Kedley_Games

I cloned your bot and installed the necessary programs. I get this error now, and can't seem to track it down.

An error occurred while running the command: TypeError: Cannot read property 'duration' of undefined

Seems to occur with whichever youtube link I enter, whether a long or short video.
Thoughts appreciated.

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galnir profile image
Nir Author

Hey, please open an issue in the bot's repo on Github and fill the issue template
github.com/galnir/Master-Bot

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yoshiyukiadly profile image
يوشيىوکي عدلي • Edited on

UnhandledPromiseRejectionWarning: DiscordAPIError: Invalid Form Body

hi sorry to disturb, after install git it able to run , and when trying make it online, it return error as above shown in image. is ti means my discord id in config.json is wrong?

TypeError [CLIENT_MISSING_INTENTS]: Valid intents must be provided for the Client.
also got this error after install master discord.js

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valentijnslijper profile image
ValentijnSlijper

Upon running the node.js and fixing all the missing modules. I get this error and I can't find a solution.

First, the bot starts without a problem but after trying to play a song the bot joins the channel and crashes with the error: secretbox.methods.close is not a function.

Any help is appreciated,
Thanks in advance.


D:\Git\Private\Master-Bot-master>node index.js
Ready!
D:\Git\Private\Master-Bot-master\node_modules\discord.js\src\client\voice\dispatcher\StreamDispatcher.js:262
return [secretbox.methods.close(buffer, this._nonceBuffer, secret_key), this._nonceBuffer.slice(0, 4)];
^

TypeError: secretbox.methods.close is not a function
at StreamDispatcher._encrypt (D:\Git\Private\Master-Bot-master\node_modules\discord.js\src\client\voice\dispatcher\StreamDispatcher.js:262:33)
at StreamDispatcher._createPacket (D:\Git\Private\Master-Bot-master\node_modules\discord.js\src\client\voice\dispatcher\StreamDispatcher.js:281:49)
at StreamDispatcher._playChunk (D:\Git\Private\Master-Bot-master\node_modules\discord.js\src\client\voice\dispatcher\StreamDispatcher.js:253:27)
at StreamDispatcher._write (D:\Git\Private\Master-Bot-master\node_modules\discord.js\src\client\voice\dispatcher\StreamDispatcher.js:107:10)
at doWrite (_stream_writable.js:403:12)
at writeOrBuffer (_stream_writable.js:387:5)
at StreamDispatcher.Writable.write (_stream_writable.js:318:11)
at SingleSilence.ondata (_stream_readable.js:717:22)
at SingleSilence.emit (events.js:315:20)

at SingleSilence.Readable.read (_stream_readable.js:506:10)

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ogskies profile image
OGSkies

Hello Nir, I know everyone says that word but Idk what to say other than that
I checked your bot and used it but there is a small problem, is that it doesn't enter the VC and it doesn't
responds to me ever, I added every thing and the API, youtube API summary I added everything but the bot doesn't respond to me so if you can help I would appreciate that

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galnir profile image
Nir Author

Make sure you installed all the requirements correctly(python 2.7, ffmpeg) and also make sure that running 'npm i node-opus' doesn't fail

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anjayanimabar12 profile image
Hezza

Hello Nir, I got a problem at line 90 like these

const playlist = await youtube.getPlaylist(query); // get playlist data
^^^^^

SyntaxError: await is only valid in async function
pls react this pls...

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galnir profile image
Nir Author

It shouldn't happen unless you copied code over to another bot. If you want this to work perfectly, clone the master-bot repo and follow the instructions on the repo's page. Also this guide is outdated so it will not work well

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zeus1017 profile image
zeus1017
          const video = await youtube.getVideoByID(id);
                        ^^^^^

SyntaxError: await is only valid in async function
?[90m at wrapSafe (internal/modules/cjs/loader.js:1072:16)?[39m
?[90m at Module._compile (internal/modules/cjs/loader.js:1122:27)?[39m
?[90m at Object.Module._extensions..js (internal/modules/cjs/loader.js:1178:10)?[39m
?[90m at Module.load (internal/modules/cjs/loader.js:1002:32)?[39m
?[90m at Function.Module._load (internal/modules/cjs/loader.js:901:14)?[39m
?[90m at Module.require (internal/modules/cjs/loader.js:1044:19)?[39m
?[90m at require (internal/modules/cjs/helpers.js:77:18)?[39m

-can you plz help me with that?

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ogskies profile image
OGSkies

Hello Nir, I know everyone says that word but Idk what to say other than that
I checked your bot and used it but there is a small problem, is that it doesnt enter the vc and it doesnt
responds to me ever, i added every thing and the api, youtube api summary i added everything but the bot doesnt reponds to me so if you can help i would apreciate that

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tigulima profile image
Te Rasgo Shiny

Hi Nir! Thx for this awesome work u r sharing. But I'd still need some more of ur help... I installed discord.js-commendo but it won't recognize it, leaving me with the problem:

"Error: cannot find module 'discord.js-commando'"

I've been searching what could it be for the last couple of days and I've got nothing... What should I do?

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galnir profile image
Nir Author

I think you misspelled the name of the package, it's as the error says 'discord.js-commando' and not 'commendo'.
It shouldn't throw any errors, all you need to do is install it in the right directory using npm or yarn

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satanis0504 profile image
Satanis0504

Hello, I am a beginner. After basically following your steps and using command !play I have this error and my bot says this:

An error occurred while running the command: TypeError: Cannot read property 'isTriviaRunning' of undefined
You shouldn't ever receive an error like this.
Please contact [my discord id]

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galnir profile image
Nir Author

This usually happens if you copy code instead of cloning the repository. Make sure you clone it using Git and follow the instructions in the repository

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neeeeeeedonuts profile image
NeeeeeeeDonuts

Hello Nir, I imported the packages and got This Error.

TypeError: Cannot read property 'extend' of undefined

Please help!

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galnir profile image
Nir Author

You did not install the master version of discord.js

enter
npm i discordjs/discord.js

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