# SandboxServerReloadError

> **Class** in `langsmith`

📖 [View in docs](https://reference.langchain.com/python/langsmith/sandbox/_exceptions/SandboxServerReloadError)

Raised when the server sends a 1001 Going Away close frame.

This indicates a server hot-reload, not a true connection failure.
The command is still running on the server.

This is a subclass of SandboxConnectionError, so the auto-reconnect
logic in CommandHandle catches it along with all other
connection errors. The distinction matters for retry strategy:
SandboxServerReloadError triggers immediate reconnect (no backoff),
while other SandboxConnectionError triggers exponential backoff.

Users typically never see this exception — it's handled internally.

## Signature

```python
SandboxServerReloadError()
```

## Extends

- `SandboxConnectionError`

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[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/19dc497a3d89638e4cc35db72ea1c29cad35cbbf/python/langsmith/sandbox/_exceptions.py#L47)