Events and middleware

Use discriminated union events and the middleware pipeline to shape bot behavior early.

Event handlers

You subscribe with client.on(...) and receive typed event payloads:

client.on('MESSAGE_DELETE', (event) => {
  console.log(event.messageId)
  console.log(event.message?.content)
})

Middleware

client.use(...) lets you intercept events before downstream handlers:

client.use((event, next) => {
  if (event.type === 'MESSAGE_CREATE' && event.message.author.bot) return
  next()
})

Why this matters

Middleware is a good fit for:

• dropping bot messages
• guild allowlists
• rate limiting or coarse feature gates
• logging and metrics

Event typing

The event system is one of Chameleon’s best DX wins:

• the event name narrows the payload shape
• event.type supports further narrowing in shared flows
• you avoid a lot of nullable probing that is common in untyped gateway payload handling