# File Header

> [!note] Tato stránka ještě není přeložena do češtiny a zobrazuje se anglicky.


The file header, encoded using the CBOR format, contains critical metadata about the RAE file and its content. The `RaeBinaryFile` is the root record for the RAE file format in its binary representation. It starts directly after the terminator byte of the magic string (see [File Identification](rhopoint-elements-hub-rae-file-format-file-identification.md)) and extends to the end of the file.

### Properties

- **Format** (required):\
Identifies the data format contained within the file. For now, only `"MeasurementComponentMetaTuple[]"` is supported — an array of [MeasurementComponentMetaTuple](rhopoint-elements-hub-rae-file-format-measurementcomponentmetatuple.md) records.
- **Version** (required):\
Indicates the version of the file format. The current version is `1`.
- **Compression** (optional):\
Specifies the compression algorithm used for the `Data` byte array. If not set, it defaults to `"none"`. Currently, only `"gzip"` is supported.
- **EncryptionAlgorithm** (optional):\
Specifies the encryption algorithm applied to the data (if any). Encryption is not implemented in the current version; files are written with `"none"`.
- **HashAlgorithm** (optional):\
Describes the hashing algorithm used to validate data integrity. Currently `"sha256"`.
- **Hash** (optional):\
A hash string used for data integrity checks. It is calculated over the `Data` byte array **as stored in the file** (i.e. after compression), using the algorithm specified in `HashAlgorithm`.
- **DataContainer** (required):\
Indicates the encoding of the payload inside `Data` after decompression. Currently, this is always `"cbor"`.
- **DataSize** (required):\
The size of the `Data` byte array in bytes.
- **Data** (required):\
The actual measurement data stored as a byte array. The data is compressed using the specified compression algorithm (or left uncompressed if `Compression = "none"`) and contains a CBOR-encoded container matching the `Format`.

> [!note]
> In the CBOR encoding, the map keys are the property names in **lowerCamelCase**: `format`, `version`, `compression`, `encryptionAlgorithm`, `hashAlgorithm`, `hash`, `dataContainer`, `dataSize`, `data`. The `Data` byte array is stored as a CBOR byte string.

### Declaration

```csharp
public record RaeBinaryFile
{
    public required string Format { get; set; }
    public required int Version { get; set; }
    public string? Compression { get; set; }
    public string? EncryptionAlgorithm { get; set; }
    public string? HashAlgorithm { get; set; }
    public string? Hash { get; set; }

    public required string DataContainer { get; set; }
    public required int DataSize { get; set; }
    public required byte[] Data { get; set; }
}
```