Websockets are a natively supported way for a server communicating with a player in Minecraft. The official Script API of Minecraft however is generally preferred over using a websocket connection. Here are some major reasons why you would use websockets instead of a Script API:
- programmatically modify/manage a Minecraft world hosted on a console1
- use another language than JavaScript (or one that transpiles to JavaScript)2
Warning
Websockets are not natively supported on every device that runs Minecraft. Establishing a connection to a websocket server is only possible on mobile and desktop devices and not consoles. However another player is able to be connected to the server which then is capable of running commands in that world.
sequenceDiagram
Server-)Client: subscribe to event "PlayerMessage"
Server-)Client: run `tp @a 10 10 10`
Client-)Server: response: teleported entities
Client-)Server: "Alice" sent "Hello World"
Note
The server can only listen to events that the client triggers. For example if another
player sends a message in the chat, the event PlayerMessage is not triggered. The
server also runs commands as the client which means that @s refers to the player
connected to the server and relative coordinates are relative to that player. More
players may connect to the same server but this has not been tried out yet so feel
free to let us know if it works.
Implementing servers that handle events takes a long time and is very inconvenient so we try to implement wrappers around it in different programming languages. At the moment only Python is supported.
After you have started a server you can connect to it via the /wsserver (or its alias
/connect) command by typing it in the Minecraft chat.
/connect localhost:6464Because websockets in Minecraft are not maintained anymore and have never been officially documented we will provide a (digital) book going in-depth how websockets in Minecraft work so the implementation in other programming languages can be done more easily.
Some applications that work with websockets are published here as well.
Footnotes
-
Console players (Playstation/XBox/Switch/...) cannot download behaviour packs from sources other than the Marketplace Store. Because connecting to a websocket server is also not possible, it is required to join that world on a mobile or desktop device. ↩
-
Keep in mind that the functionality is very limited with websockets compared to the Script API. If your project relies on something that cannot be done with JavaScript for example using some library that is only present in a different language.
JavaScript is not that hard and it can be fun and useful to learn an entire new programming language. You may as well take a look at TypeScript. ↩