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

# On Message • AI Agent SDK

> on_message: Register callback for text messages.

# on\_message

<div className="flex items-center gap-2">
  <Badge color="purple">Method</Badge>
</div>

> This is a method of the [**RealtimeAgent**](../classes/RealtimeAgent) class in the [**realtime\_agent**](../modules/realtime_agent) module.

Register callback for text messages.

## Signature

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
def on_message(callback: Callable[[str], None]) -> None
```

## Parameters

<ParamField query="callback" type="Callable" required={true}>
  Function to call with message text
</ParamField>

## Source

<Card title="View on GitHub" icon="github" href="https://github.com/MervinPraison/PraisonAI/blob/main/src/praisonai-agents/praisonaiagents/agent/realtime_agent.py#L349">
  `praisonaiagents/agent/realtime_agent.py` at line 349
</Card>