```python
from fastapi import FastAPI
import asyncio

import helpers  # noqa: F401  (the provided API)

app = FastAPI()


@app.post("/documents", status_code=201)
async def save_document(name: str, text: str):
    # Run the blocking helper in a separate thread to avoid blocking the event loop
    bytes_len = await asyncio.to_thread(helpers.save_document, name, text)
    return {"bytes": bytes_len}
```