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

# on_message

Decorator to react to messages coming from the UI.
The decorated function is called every time a new message is received.

## Parameters

<ParamField path="message" type="cl.Message">
  The message coming from the UI.
</ParamField>

## Usage

```python theme={null}
import chainlit as cl

@cl.on_message
def main(message: cl.Message):
  content = message.content
  # do something
```