# MeasurementComponentMetaTuple

> [!note] Deze pagina is nog niet in het Nederlands beschikbaar en wordt in het Engels weergegeven.


After decompression (see [Decompression and parsing](rhopoint-elements-hub-rae-file-format-decompression-and-parsing.md)), the payload of an RAE file is a **CBOR array**. Each element of the array is one `MeasurementComponentMetaTuple` — a pair of the searchable metadata (`Meta`) and the actual measurement tree (`Component`) of a single measurement.

```csharp
public record MeasurementComponentMetaTuple
{
    public required MeasurementMeta Meta { get; init; }
    public required MeasurementComponent Component { get; init; }
}
```

In the CBOR encoding, each tuple is a map with two keys:

| Key | Type | Description |
|---|---|---|
| `meta` | map | The `MeasurementMeta` record (see below) |
| `component` | map | The root [MeasurementComponent](rhopoint-elements-hub-rae-file-format-measurementcomponent.md) of the measurement tree |

### Encoding rules

These rules apply to the whole payload (tuples, components, and data records):

- **Map keys** are the property names in **lowerCamelCase** (e.g. `MeasurementIdentifier` → `measurementIdentifier`).
- **Unset properties** are written as CBOR `null`; parsers must treat `null` and a missing key the same way.
- **Enum values** are written as lowerCamelCase strings (e.g. `Single` → `"single"`, `FileReference` → `"fileReference"`).
- **Timestamps** are ISO 8601 round-trip strings in UTC (e.g. `"2026-07-07T12:34:56.7890123+00:00"`).
- **Byte arrays** are CBOR byte strings.

> [!note]
> The [JSON Variant](rhopoint-elements-hub-rae-file-format-json-variant.md) of the RAE format uses different, abbreviated key names. The tables below list both.

### MeasurementMeta

`MeasurementMeta` holds the descriptive, searchable metadata of a measurement. It is stored separately from the measurement tree so applications can list and filter measurements without loading the (potentially large) measurement data.

| Property | CBOR key | JSON key | Type | Description |
|---|---|---|---|---|
| Identifier | `identifier` | `id` | string | Database identifier of the meta record. May be `null`; importers typically discard it and assign a new one. |
| Version | `version` | `ver` | integer | Schema version of the record. Currently `2`. |
| SourceIdentifier | `sourceIdentifier` | `srcId` | string | Identifier assigned by the system that produced the measurement (a GUID). Stable across export/import. |
| MeasurementIdentifier | `measurementIdentifier` | `mId` | string | Identifier of the measurement component this meta record belongs to. |
| ModuleIdentifier | `moduleIdentifier` | `modId` | string | Identifier of the software module that produced the measurement. |
| MeasurementType | `measurementType` | `mType` | string (enum) | Type of the root component, see [MeasurementComponent](rhopoint-elements-hub-rae-file-format-measurementcomponent.md) for the list of values. |
| Timestamp | `timestamp` | `time` | string (ISO 8601) | Time the measurement was stored. |
| SourceTimestamp | `sourceTimestamp` | `srcTime` | string (ISO 8601) | Time the measurement was taken on the source device. |
| Index | `index` | `index` | integer | Sequential index of the measurement. |
| Name | `name` | `name` | string | Display name of the measurement. |
| Project | `project` | `proj` | string | Project the measurement is assigned to. |
| Batch | `batch` | `bat` | string | Batch the measurement is assigned to. |
| Customer | `customer` | `cust` | string | Customer the measurement is assigned to. |
| Comments | `comments` | `com` | string | Free-text comments. |
| Tags | `tags` | `tag` | array of strings | User-defined tags. |
| SearchableText | `searchableText` | `search` | string | Pre-built text used for full-text search. |

### Example (CBOR diagnostic notation)

```
[
  {
    "meta": {
      "identifier": null,
      "version": 2,
      "sourceIdentifier": "0d9f4c1e-6a2b-4f43-9c1a-2f5e8d7b3a10",
      "measurementIdentifier": "0d9f4c1e-6a2b-4f43-9c1a-2f5e8d7b3a10",
      "moduleIdentifier": "surface-brilliance",
      "measurementType": "composite",
      "timestamp": "2026-07-07T12:34:56.7890123+00:00",
      "sourceTimestamp": "2026-07-07T12:34:55.1230000+00:00",
      "index": 42,
      "name": "Sample A",
      "project": "Door panels",
      "batch": "Batch 7",
      "customer": null,
      "comments": null,
      "tags": ["oem", "topcoat"],
      "searchableText": "Sample A Door panels Batch 7"
    },
    "component": { ... }
  }
]
```

The structure of the `component` map is described in [MeasurementComponent](rhopoint-elements-hub-rae-file-format-measurementcomponent.md).