---
id: "M:cAlgo.API.File.WriteAllBytes(System.Byte[])"
kind: "method"
type: "T:cAlgo.API.File"
url: "https://help.ctrader.com/ctrader-algo/references/Utility/File/WriteAllBytes/"
---

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

# File.WriteAllBytes

Member of [File](https://help.ctrader.com/ctrader-algo/references/Utility/File/index.md).

## WriteAllBytes(byte[] bytes)

Overwrites file content with passed bytes.

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

- Cloud: Exists returns false; reads return empty string/array; writes and appends silently do nothing. No exception.

C#:

```csharp
void WriteAllBytes(byte[] bytes)
```

Python:

```python
file.WriteAllBytes(bytes: list[int]) -> None
```

### Parameters

- `bytes` (`byte[]`, Python `list[int]`): Bytes to write

Available since cAlgo.API 5.7.

### Examples

C#:

```csharp
protected override void OnStart()
{
    DataFile.WriteAllBytes(Encoding.UTF8.GetBytes(SymbolName + "," + Symbol.Bid));
}
```

Python:

```python
from System.Text import Encoding

api.DataFile.WriteAllBytes(Encoding.UTF8.GetBytes(f"{api.SymbolName},{api.Symbol.Bid}"))
```

config.json:

```json
{
  "Parameters": [
    {
      "Name": "DataFile",
      "DisplayName": "Data File",
      "Type": "File"
    }
  ]
}
```