# message_source

> **Function** in `deepagents_code`

📖 [View in docs](https://reference.langchain.com/python/deepagents-code/goal_state_notice/message_source)

Return a message's `lc_source` value when present.

## Signature

```python
message_source(
    message: object,
) -> str | None
```

---

[View source on GitHub](https://github.com/langchain-ai/deepagents/blob/2069079e09546060f5b52b2cd4f0e3c813e820f3/libs/code/deepagents_code/goal_state_notice.py#L179)