> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tess.im/llms.txt
> Use this file to discover all available pages before exploring further.

# Mention files and agents with @ in chat

> Type @ in the chat box to place conversation files directly inside your sentence as chips, or switch the turn to another agent in chat.

Typing `@` in the chat message box opens a single menu where you can reference **Files** already in the conversation or, at the start of an empty message, trigger **Agents** without leaving the current chat.

## When each section appears

The menu adapts to where you type `@` and what is enabled for your account.

| Section | When it appears | What selecting an item does |
| - | - | - |
| **Files** | Whenever you type `@` at the start of the message or after a space, in the first message, in follow-ups, and when editing an earlier message | Inserts a file chip at the cursor so you can keep writing your sentence |
| **Agents** | Only when `@` (and the search text right after it, with no spaces) is the entire content of the main chat box and **External Agent Chat** is enabled | Clears `@` from the box and routes the turn to the selected agent |

## Mention a file in your sentence

**1. Type @ where the file belongs**

At the beginning of a message or after a space, type `@`. To filter the list, type part of the file name right after `@` with no spaces. Files whose name starts with your text appear first, followed by files whose name contains it.

**2. Check the thumbnail or format icon**

Under **Files**, images display a thumbnail and other documents show a format icon with the file extension kept visible at the end, even when a long file name is shortened.

**3. Pick the file from the menu**

Use the `↑` and `↓` arrow keys and press `Enter`, or click the file. Press `Esc` or `Tab` to close the menu without inserting anything. The file lands at the cursor as a chip followed by a space.

**4. Send your message**

Mentioning a file that is already in the conversation references that file in place without uploading its content again. When Tess cites that file in a reply, it shows as a link with the file name.

> [!NOTE]
>
> The **Files** list in the `@` menu includes attachments sent in the conversation and files generated in it. Documents attached to an agent's fixed Knowledge Base in Agent Studio are still consulted by the agent automatically, but they do not appear in the `@` menu yet.

## How inline file chips work

> [card] Exact spot in the text
>
> Files chosen with `@`, dragged in, pasted (`Ctrl+V` or `⌘V`), or added from **+** > **Add photos & files** sit in the text as chips at the cursor. Drag any chip to move it to another point in your sentence.

> [card] Upload progress on Send
>
> While new attachments are uploading, the Send button stays blocked, displays a progress ring, and shows on hover how many files in the batch are ready, including when you edit a message.

> [card] Remove without deleting
>
> Clicking `×` on a chip removes the reference from that message without deleting the uploaded file. Using **Improve prompt** (the wand icon) keeps all file chips in your message.

> [card] Access and error notices
>
> If you cannot access a referenced file or verification fails, hovering over the chip explains why. Remove the chip with `×` or upload the file again to unblock sending.

## Trigger another agent with @

When the **External Agent Chat** addon is enabled for your account and workspace, typing `@` in an empty chat box displays **Agents** below the conversation files:

1. In an empty main chat box, type `@` to see recent agents, or type `@` followed by a name to search.
2. Use the arrow keys or click the agent you want. Private agents, or agents that cannot be mentioned from another chat, cannot be selected.
3. Write your prompt as usual. That turn runs with the selected agent while keeping the current conversation history.

To enable or learn more about this account module, see [Addons](https://docs.tess.im/en/addons.md).

## Example prompts with @

* `Compare @[q3-report.pdf] with @[q4-forecast.xlsx] and list variances above 10%.`
* `Follow the voice guidelines in @[brand-book.pdf] to rewrite the proposal below.`
* `Extract every deadline from @[vendor-agreement.docx] into a table by owner.`

See also: [Using the Chat](https://docs.tess.im/en/chat.md) · [Knowledge Base](https://docs.tess.im/en/chat/kb.md) · [Supported Files](https://docs.tess.im/en/supported-files.md) · [Addons](https://docs.tess.im/en/addons.md).


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