---
id: "P:cAlgo.API.BacktestingDataSourceOptions.DataRequestHandler"
kind: "property"
type: "T:cAlgo.API.BacktestingDataSourceOptions"
url: "https://help.ctrader.com/ctrader-algo/references/Plugin/Backtesting/DataSource/BacktestingDataSourceOptions/DataRequestHandler/"
---

> Documentation index for agents: https://help.ctrader.com/ctrader-algo/llms.txt · machine index: https://help.ctrader.com/ctrader-algo/api.json

# BacktestingDataSourceOptions.DataRequestHandler

Member of [BacktestingDataSourceOptions](https://help.ctrader.com/ctrader-algo/references/Plugin/Backtesting/DataSource/BacktestingDataSourceOptions/index.md).

## DataRequestHandler

Handler function for handling data requests.

Environments: Desktop supported · CLI not supported · Cloud not supported.

- CLI: Available to plugins only, and plugins cannot run in the CLI.
- Cloud: Available to plugins only, and plugins cannot run in the cloud.

C#:

```csharp
public Action<BacktestingDataRequest> DataRequestHandler {get; set;}
```

Python:

```python
backtestingDataSourceOptions.DataRequestHandler: Callable[[BacktestingDataRequest], None]
```

### Returns

`Action<BacktestingDataRequest>` — 

Available since cAlgo.API 5.3.