# start_payload

> **Function** in `langsmith`

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

Build the body for ``/execute/stream/start``.

## Signature

```python
start_payload(
    command: str,
    *,
    command_id: str,
    timeout: int,
    shell: str,
    idle_timeout: int,
    ttl_seconds: int,
    env: Optional[dict[str, str]] = None,
    cwd: Optional[str] = None,
    run_config: Optional[dict[str, Any]] = None,
) -> dict[str, Any]
```

---

[View source on GitHub](https://github.com/langchain-ai/langsmith-sdk/blob/19d52419f47c93ca2c57a0d51c58d255f5949092/python/langsmith/sandbox/_sse_execute.py#L122)