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Documentation Index

Fetch the complete documentation index at: https://bun.com/docs/llms.txt

Use this file to discover all available pages before exploring further.

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server.pendingRequests and server.pendingWebSockets

Monitor server activity with built-in counters: 
const server = Bun.serve({
  fetch(req, server) {
    return new Response(
      `Active requests: ${server.pendingRequests}\n` + `Active WebSockets: ${server.pendingWebSockets}`,
    );
  },
});

​
server.subscriberCount(topic)

Get count of subscribers for a WebSocket topic: 
const server = Bun.serve({
  fetch(req, server) {
    const chatUsers = server.subscriberCount("chat");
    return new Response(`${chatUsers} users in chat`);
  },
  websocket: {
    message(ws) {
      ws.subscribe("chat");
    },
  },
});