Chat Event

This script is peak of human evolution. Whenever someone says "Creeper" in chat, it replies with "Aw man".

onEvent('player.chat', (event) => {
  // Check if message equals creeper, ignoring case
  if (event.message.trim().equalsIgnoreCase('creeper')) {
    // Schedule task in 1 tick, because if you reply immidiently, it will print before player's message
    event.server.scheduleInTicks(1, event.server, (callback) => {
      // Tell everyone Aw man, colored green. Callback data is the server
      callback.data.tell(Text.green('Aw man'))
    })
  }
})

Another example, cancelling the chat event. No need to schedule anything now, because player's message wont be printed,

onEvent('player.chat', (event) => {
  // Check if message equals creeper, ignoring case
  if (event.message.startsWith('!some_command')) {
    event.player.tell('Hi!')
    event.cancel()
  }
})