# Sources and @mentions

Decide where the agent looks with source toggles and @mentions.

By default the agent chooses its own sources: your library for questions about your papers, the web when current information helps. You can steer it for one message or a whole conversation.

## Source toggles [#source-toggles]

Two toggles below the chat input switch sources on or off for the conversation.

* Turn off **web search** to keep answers grounded in your own documents. This is the usual choice for literature reviews and writing.
* Turn off **library search** to answer from the web without mixing in your files.
* Turn off both, with a file open, to scope the chat to that file alone.

## @mentions [#mentions]

Type `@` in the chat input to open a menu with three groups. You can use several in one message.

| Group   | Options                                                     | Use it to                      |
| ------- | ----------------------------------------------------------- | ------------------------------ |
| Sources | Library, Web, and each connected app or database            | Tell the agent where to search |
| Tools   | Create note, Edit note, Create citation, Create image, Plan | Ask for a specific action      |
| Files   | Your recent files                                           | Focus on particular documents  |

`@Web` covers the open web and academic papers. For example:

```text
@PubMed @Library Which trials in my library disagree with the latest PubMed evidence on GLP-1 agonists and weight maintenance?
```

Connected apps appear under Sources only after you set them up. See [Connectors](/guides/connectors).

## Which to use [#which-to-use]

* Use **@mentions** to add a source or trigger a tool for one message.
* Use the **toggles** to restrict sources for the whole conversation.
* Use **folders** to scope a project: Agent chat treats the open folder as its context, and folder chat covers every file in it, including subfolders.