# append_to_system_message

> **Function** in `deepagents`

📖 [View in docs](https://reference.langchain.com/python/deepagents/middleware/_utils/append_to_system_message)

Append text to a system message.

## Signature

```python
append_to_system_message(
    system_message: SystemMessage | None,
    text: str,
) -> SystemMessage
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `system_message` | `SystemMessage \| None` | Yes | Existing system message or None. |
| `text` | `str` | Yes | Text to add to the system message. |

## Returns

`SystemMessage`

New SystemMessage with the text appended.

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[View source on GitHub](https://github.com/langchain-ai/deepagents/blob/a9e6e4f7ad7fe161dd9affc3d74bb19784aca70b/libs/deepagents/deepagents/middleware/_utils.py#L6)