# Metrics (/docs/runtime/http/metrics)

<!-- agent-signals: reading_time_min: 1 · est_tokens: 186 · updated: 2026-07-28 -->
Related: [Server](/docs/runtime/http/server.md), [Routing](/docs/runtime/http/routing.md), [Cookies](/docs/runtime/http/cookies.md), [TLS](/docs/runtime/http/tls.md), [Error Handling](/docs/runtime/http/error-handling.md), [Cookies](/docs/runtime/cookies.md)

### `server.pendingRequests` and `server.pendingWebSockets` [#serverpendingrequests-and-serverpendingwebsockets]

Monitor server activity with built-in counters:

```ts
const server = Bun.serve({
  fetch(req, server) {
    return new Response(
      `Active requests: ${server.pendingRequests}\n` + `Active WebSockets: ${server.pendingWebSockets}`,
    );
  },
});
```

### `server.subscriberCount(topic)` [#serversubscribercounttopic]

Get the number of subscribers for a WebSocket topic:

```ts
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");
    },
  },
});
```