A message object that when set indicates a thread is open.
When used with the [`Thread`](../../../../ui-components/thread.mdx) component this will display the thread.
When used with the standard [`MessageList`](../../../../ui-components/message_list.mdx) component this will prevent any singleton components in the [`OverlayProvider`](../../../../core-components/overlay-provider) form getting out of sync.

:::note

`thread` should be set on all `Channel` components when a thread is open.

:::

| Type |
| - |
| object |