> For the complete documentation index, see [llms.txt](https://zumo.fusion.ac/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zumo.fusion.ac/api-reference/websocket/envelope.md).

# Envelope

Present on every lobby fan-out event:

| Field       | Type   | Description                                                                           |
| ----------- | ------ | ------------------------------------------------------------------------------------- |
| `botId`     | string | Producer identity, e.g. `"duels-1"`                                                   |
| `mode`      | string | Game mode slug, lowercase                                                             |
| `lobbyId`   | number | Hypixel lobby number                                                                  |
| `timestamp` | number | Unix seconds (fractional allowed)                                                     |
| `category`  | string | `lobby`, `replay`, `temporaryLeaderboard`, `lifetimeLeaderboard`, `ban`, or `bedwars` |

Replay lifecycle events use `botId`, usually `mode: "replay"`, and `timestamp`, but **omit `lobbyId`**. Exception: [`replayFinished`](/api-reference/replay-events/replay-finished.md) sets `mode` to the in-game mode.