`m.room.history_visibility` controls who can view the room history.
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- [Example](#example)
- [Options](#options)
- [See also](#see-also)
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## Example
```json
{
"history_visibility": "invited"
}
```
## Options
[Refer to the upstream for canonical information.](https://spec.matrix.org/latest/client-server-api/#room-history-visibility)
-`world_readable` - anyone can read the history without joining, and it
likely will be indexed by search engines.
-`shared` - history is shared to all users in the room, regardless of when
they joined.
- [Matrix public archive will publish history of rooms with this option although not allow search engines to index.](https://github.com/matrix-org/matrix-public-archive/blob/main/docs/faq.md#why-does-the-archive-user-join-rooms-instead-of-browsing-them-as-a-guest)
-`invited` - users can see history from the point of time they were invited
to the room. **_RECOMMENDED FOR SEMI-PUBLIC ROOMS_**
-`joined` users can see history from the point of time they joined
**_WARNING!_** Changing the option **will not affect old messages**.
