[Python] How to make a non-blocking Websocket endpoint in FastAPI?

I'm fairly new to async in Python. Currently I'm trying to implement a Websocket endpoint with FastAPI that performs a long-running task. The following code is used:

@router.websocket("/ws/catalog.check")
async def websocket_endpoint(ws: WebSocket, user: Annotated[UserWithGroupEntity, Depends(user_middleware_ws)]) -> None:
manager = WSManager()
await manager.connect(ws)

try:
raw_req = await ws.receive_json()
req = CatalogCheckRequest.model_validate(raw_req)

await manager.send_personal_json(CatalogCheckResponse(message=CatalogCheckMessage(data='Process started')),
ws)

#long-running task
check_result = await create_task(CatalogHandler.catalog_check(user.group_name, req.source, req.csv))

await manager.send_personal_json(CatalogCheckResponse(result=check_result), ws)
except Exception as e:
await manager.send_personal_json(CatalogCheckResponse(message=CatalogCheckMessage(data=repr(e), warning=True)),
ws)

await manager.disconnect(ws)


However, when this process is running and I'm sending request to another HTTP endpoint in gets blocked. For example, the following /health.check endpoint will only be executed when long-runnning task is finished:

@router.get("/health.check")
def health_check(config: Annotated[Config, Depends(get_config)],
log: Annotated[Log, Depends(get_logger)]) -> Dict[str, Any]:
try:
conf = config.model_dump()

log.info(conf)

resp = {"status": "ok"}
except Exception as e:
resp = {"status": repr(e)}

return resp


This messes the whole idea of my API. What can I do to make this Websocket endpoint non-blocking?

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