vanilla-discord-bridge

Caution

This project is a curiosity more than anything and may not be secure or stable enough to deploy in prod. However, I have published the source code as it may be useful for snapshot test servers. If you're looking for a Discord bridge for a regular server, though, you probably want to use Fabric/Paper instead of vanilla so you can install a Discord bridge mod/plugin. Here be dragons & etc.

A Discord bridge supporting modern vanilla servers (and modded ones, too), optionally providing two-way communication if you use the wrapper mode.

Lack of rich content support (i.e. attachments, stickers, display names/global names) is intentional so that this software works with as many Minecraft versions & Discord updates as possible.

Server Setup

Change the apiServer and apiKey as appropriate - you may use a blank API key if you are sure that the API server is inaccessible from the wider internet. Otherwise, people can send fake messages to your Discord bridge. Ruh-roh!

We set the chat endpoint to "v1/chatx" so that the Minecraft server sends a more consistent request. TODO: Does this work in the earliest version of the game supporting the filter system?

text-filtering-version=0
text-filtering-config={"apiServer":"http://127.0.0.1:8080/","apiKey":"API_KEY","endpoints":{"chat":"v1/chatx"}}

Discord Bot

You must create a Discord bot if you wish for your Discord users to be able to communicate to your Minecraft players. Make sure that it has the MESSAGE_CONTENT intent. Additionally, you must choose either Wrapper Mode or RCon mode.

Wrapper Mode

In order to allow Discord users to communicate with Minecraft servers via Minecraft chat, vanilla-discord-bridge can launch your server and inject tellraw into the process input. You will still be able to input commands via process input, but you will not be able to tab complete them on server implementations that support console tab completions.

To launch the server wrapped by vanilla-discord-bridge, invoke vanilla-discord-bridge with the full command line you use to launch your server without the wrapper (i.e. PERHAPS_SOME_ENV_HERE=1 java -jar server.jar --nogui would become PERHAPS_SOME_ENV_HERE=1 API_KEY=SECURE_API_KEY WEBHOOK_ID=00000000000 WEBHOOK_TOKEN=WEBHOOK_TOKEN_HERE DISCORD_TOKEN=DISCORD_TOKEN_HERE DISCORD_CHANNEL_ID=00000000000 vanilla-discord-bridge java -jar server.jar --nogui). Specifying DISCORD_TOKEN requires that you specify DISCORD_CHANNEL_ID, and vice-versa.

RCon Mode

Caution

Make sure that the wider Internet is unable to access your RCon port, as this will leave your server susceptible to bruteforce attacks, even if you choose a secure password.

Caution

If you are going to connect to the RCon port over an untrusted network (i.e. the Internet), you should consider using software like Nebula, Wireguard, OpenVPN, Tailscale or ZeroTier which provide a much-needed layer of encryption (as RCon is entirely unencrypted and thus incredibly susceptible to surveillance and incredibly easy MITM) and authentication.

Supply an address in the RCON_HOST environment variable, and supply the password in the RCON_PASS environment variable. That's it, just make sure you read the warnings above!

Environment variables

Name	Default	Type	Description
API_KEY	-	String	The API key we check to ensure the filter request originated from the server. This is most important when you are running the server in standalone mode on a different machine, although that setup is not recommended as it will noticeably increase message latency if not over LAN.
BIND_ADDRESS	127.0.0.1:8080	Socket Address	Address the filter server should listen on. This needs to be synced with server.properties
WEBHOOK_ID	-	u64	The numeric ID of the webhook.
WEBHOOK_TOKEN	-	String	The token of the webhook.
DISCORD_TOKEN	-	String	Token of the Discord bot for wrapper mode.
DISCORD_CHANNEL_ID	-	u64	ID of the bridge channel so we can ignore messages from elsewhere.
ALLOW_EVERYONE_MENTION	false	bool	Should Minecraft users be able to mention @everyone?
ALLOW_USER_MENTION	false	bool	Should Minecraft users be able to mention users?
ALLOW_ROLE_MENTION	false	bool	Should Minecraft users be able to mention roles?
EMBED_URL	false	bool	Should URLs sent by Minecraft users embed on Discord?
TELLRAW_PREFIX	tellraw @a	String	The command to prefix a space and the component with. Useful if Essentials overwrites vanilla tellraw, or if you want to customize which players can see the Discord bridge.
RCON_HOST	-	Socket Address	RCON address to connect to instead of wrapping server launch
RCON_PASS	-	String	RCON password