---
title: Thread IDs
description: The zoom thread format, how a channel is told apart from a DM, and exactly when decoding fails.
---

Every thread the adapter hands you carries the Zoom conversation it came from,
written into the ID:

```
zoom:{channelId}:{messageId}
```

`channelId` is a Zoom JID. `messageId` is the event timestamp for a
`bot_notification`, the mention's message UUID for a top-level
`team_chat.app_mention`, or `reply_main_message_id` when the mention is inside a
thread. `team_chat.app_mention` sends a bare channel ID, so the adapter appends
`@conference.xmpp.zoom.us` before building the thread ID.

<ThreadIdPlayground />

## Channel or direct message

The JID suffix is the only signal the adapter has, and it is enough:

| JID ends in | Treated as |
| --- | --- |
| `@conference.xmpp.zoom.us` | A channel |
| anything else | A direct message |

`adapter.isDM(threadId)` answers the same question for you.

## Decoding

`decodeThreadId(threadId)` returns `{ channelId, messageId }`.

- `zoom:abc@conference.xmpp.zoom.us:1750000000000` → both parts, as written.
- `zoom:abc@conference.xmpp.zoom.us` → `messageId` is `""`. This is a
  channel-level ID, which is what you post a brand new message to.
- `zoom::1750000000000` → throws a `ValidationError`: the channel ID is empty.
- `slack:C123` → throws a `ValidationError`: the ID does not start with `zoom:`.

`zoom:` on its own does not throw — with nothing after the prefix there is no
second colon to split on, so it decodes to an empty channel ID and an empty
message ID. The Zoom API call made with it is what will fail.

:::note
A thread ID is not a conversation for `bot_notification`. Zoom gives every incoming
bot message a fresh `event_ts`, so two messages a person sees as one exchange produce
two unrelated thread IDs. Threaded `team_chat.app_mention` events are the exception:
they carry `reply_main_message_id`, which the adapter uses as the thread key. See
[Limitations](/limitations).
:::