Your first script

Create a file in config/questscript/scripts/. Your selected language tab is remembered and applied to other synchronized examples.

JavaScript

welcome.js

world.afterEvents.playerJoin.subscribe((event) => {
  world.getPlayer(event.playerId)?.sendMessage('Welcome to the server!');
});

Python

welcome.py

def on_player_join(event):
    player = world.get_player(event.player_id)
    if player is not None:
        player.send_message('Welcome to the server!')

world.after_events.player_join.subscribe(on_player_join)

Load the file with:

/qs load welcome.js

Use welcome.py for Python.

Python API

Python type stubs describe the snake_case Python projection of the shared API; JavaScript declarations use camelCase. Events, players, world access, inventory, and scheduling retain the same semantics in both languages.