Imported from jarle/bun-skills (skills/bun-guides-websocket-compression/SKILL.md). Install upstream with npx skills add jarle/bun-skills --skill bun-guides-websocket-compression. Copyright stays with the author.

Enable compression for WebSocket messages

Per-message compression can be enabled with the perMessageDeflate parameter. When set, all messages will be compressed using the permessage-deflate WebSocket extension.

Bun.serve({
  // ...
  websocket: {
    // enable compression
    perMessageDeflate: true,
  },
});

To enable compression for individual messages, pass true as the second parameter to ws.send().

Bun.serve({
  // ...
  websocket: {
    async message(ws, message) {
      // send a compressed message
      ws.send(message, true);
    },
  },
});