Discord Mirror Bot

A simple app to connect with a Discord bot for the purpose of making the contents of a Discord channel available to other apps. This app has two main parts: a server to provide a web interface, and script to connect with Discord and listen for events.

server.js

The server (Express) provides the following routes:

API

• /api/bot/start - create the Discord connection and start listening for messages
• /api/bot/stop - stop listening and close the Discord connection
• /api/messages - fetch the list of the most recent messages (limit set in MESSAGE_LIMIT environment variable)
• /api/messages/:id - fetch a single message by message ID
• /api/messages/latest - fetch the most recent message (by creation date)

Web

• / - control panel for viewing bot status, starting and stopping bot

server.js expects the following environment/config variables:

• PORT=[port #] - web server port (e.g., for dev environment)
• BOTKEY=[your-app-stop-and-start-key] - to restrict stopping & starting of bot app

app.js

Uses the Discord.js NPM module to connect to Discord and listen for message-related events. The events supported include:

• message - triggered when a new message is added to the channel
• messageUpdate - triggered when an existing message has been modified
• messageDelete - triggered when a message is removed from the channel

app.js requires several environment variables to be set in order to run:

• MESSAGE_LIMIT=[up to 500] - maximum number of messages to retain
• TOKEN=[bot token from Discord Developer Portal]
• GUILD_ID=[Discord server ID]
• CHANNEL_ID=[Discord channel ID]

Prerequisites

Before running this app, you must set up a bot application on Discord and add it to a channel. Discord.js provides a very helpful guide to get you started. In particular, the sections Setting up a bot application and Adding your bot to servers will help you fulfill the prerequisites for running this app.

Note:

Pay particular attention to the bot settings for your bot on the Discord Developer Portal. In order for certain functions to work, your bot must have "Presence Intent" enabled. (This was a big headache for me.)

The app also requires a recent version of Node.js (Discord.js requires at least Node 12.0).

Installation

• Clone this repository
• Run npm install in the project root directory
• Set environment variables:
  • To run locally: Copy (or rename) the sample.env file to .env and fill in the variables with your own values
  • In production environment: set the variables described above:
    • PORT
    • BOTKEY
    • MESSAGE_LIMIT
    • TOKEN
    • GUILD_ID
    • CHANNEL_ID

Using the Application

There are two ways to use this application. 1) You can run it in standalone mode by running node app from the project's root directory. This will connect with Discord and store messages in the file data/messages.json, which you can then access directly with another application running on the same machine. Or, 2) to take advantage of the REST API routes, you can run node server from the project root, and then POST to the /api/bot/start route with your key in the POST body, e.g.,

{
   "botKey": "YOUR-AWESOME-KEY"
}

to have it start the Discord connection.

Examples

Two examples are provided in the /public/examples folder, demonstrating how the application can be integrated into a website.

• Polling: consisting of polling-example.html and polling-example.js, is an example of how to embed a Discord chat using polling to check for updates.
• Web Sockets: websockets-example.html and websockets-example.js show how to set up an embed to receive updates via web socket connections.

Future Development

• To turn this app into a fully functional Discord embed requires the ability to send messages to Discord via the app. Just sending messages as the bot user is fairly straightforward. However, allowing users to submit their own messages directly through the embed means providing a way for them to authenticate. This is possible, though it was beyond the scope of the initial intended use of this app.

• It would also be useful to have the option to restrict access--both read and write--to the mirrored chat. This would also require some form of authentication. Possibilites include requiring the user to sign into Discord through the embed (restrict access to guild members) or requiring a token granted by the bot server, tied to the embedding site.

• The decision to use a local (to the app) file as the message store was made to keep the app both simple to speed development and to operate within Heroku's free tier. Replacing the JSON messages file with a database (like MongoDB) would make it more robust and flexible.

• Another potentially useful feature would be to allow configuration through a web interface, instead of requiring that environment variables be set on the server. This would allow the server to be deployed as-is, and then the bot/Discord connection information could be supplied afterward. Such a setup would also provide the basis for a single server to support multiple simultaneous bots, connected to different Discord servers/channels.

Credits

This Node.js application relies heavily on the Discord.js package, as well as Express and Socket.io.

License

This project is released under the Unlicense. Do with it what you will.