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

# Use Custom Agents Via Chat

> Learn how to use custom agents via the UI

After [creating a new custom agent](/developer-resources/tutorials/custom-agent/create-custom-agents), you can use it via the chat. To use a custom agent, click on **Select AI mode**:

<img src="https://mintcdn.com/you/o8yXV4y4jY2RzSsv/images/custom-agents/select-ai-mode.png?fit=max&auto=format&n=o8yXV4y4jY2RzSsv&q=85&s=59706ce02604586b28a89fd2ed8ab9f9" alt="Selecting the AI mode for calling a custom agent via chat" width="1886" height="870" data-path="images/custom-agents/select-ai-mode.png" />

Then, select your custom agent from the menu:

<img src="https://mintcdn.com/you/o8yXV4y4jY2RzSsv/images/custom-agents/select-custom-agent.png?fit=max&auto=format&n=o8yXV4y4jY2RzSsv&q=85&s=f6f0cab389b76dd7538ad81fb913f06e" alt="Selecting a custom agent via chat" width="1900" height="935" data-path="images/custom-agents/select-custom-agent.png" />

You can attach files in the chat to ask the custom agent to perform actions on them by clicking on **Attach**:

<img src="https://mintcdn.com/you/o8yXV4y4jY2RzSsv/images/custom-agents/attach-files.png?fit=max&auto=format&n=o8yXV4y4jY2RzSsv&q=85&s=2c21a09afa050e6acfc5a357f8cb1cee" alt="Attaching files to the chat for custom agents" width="1891" height="870" data-path="images/custom-agents/attach-files.png" />

<Warning>
  **WARNING**: Files attached to the chat can only be used with a Custom Agent in the chat itself. Currently, attachments are not accessible when a custom agent is invoked via the API.
</Warning>