baguette

WebSockets

baguette speaks WebSockets natively — but they're opt-in: a plain HTTP app exposes no upgrade surface until you set ws. For the common case there's a built-in room/channel pub/sub; for your own protocol, use upgradeWebSocket directly.

Built-in pub/sub

Turn it on with ws: true. It mounts /api/ws/:room/:channel and tracks every connection by room + channel:

serve({ routesDir: "./api", ws: true });

Broadcast to everyone on a room + channel from anywhere — a route handler, a cron job, an automation:

import { pubSubManager } from "@prehoy/baguette";

pubSubManager.send({
  room: "org_42",
  channel: "notifications",
  message: JSON.stringify({ type: "invoice.paid", id }),
});

Clients connect to wss://your-host/api/ws/org_42/notifications and receive every message sent to that room + channel. Connections are cleaned up automatically on close. Custom path:

serve({ ws: { path: "/realtime/:room/:channel" } });

Custom WebSocket routes

For your own protocol — custom onMessage, auth on connect, per-socket state — use upgradeWebSocket on any route and mount it via onApp. Set ws: { pubsub: false } to wire the socket handler without the built-in pub/sub endpoint:

import { serve, upgradeWebSocket } from "@prehoy/baguette";

serve({
  routesDir: "./api",
  ws: { pubsub: false }, // wire WebSockets, skip the built-in room/channel endpoint
  onApp: (app) => {
    app.get(
      "/ws/echo",
      upgradeWebSocket(() => ({
        onMessage: (evt, ws) => ws.send(`echo: ${evt.data}`),
        onClose: () => console.log("closed"),
      })),
    );
  },
});

How it works

  • Opt-in — no upgrade surface exists until you set ws. serve() loads the WebSocket module and wires Bun's handler only then, so a plain HTTP app exposes nothing extra.
  • Fan-out by room + channel — pubSubManager holds connections in memory and sends only to matching subscribers.
  • Bun-native — built on Bun's WebSocket via Hono's createBunWebSocket; no socket.io, no extra dependency.

Scaling out: pubSubManager fans out within one process. Across replicas, publish through Redis (or your broker) and have each instance call pubSubManager.send from its subscriber, so a message reaches sockets on every node.

  • serve — the ws option and everything else serve() wires up.
  • Automations — DB events you might push over a socket.