Cassiopeia

Turn data from common formats into NGSI-LD entities.

Convert CSV, JSON, GeoJSON, KML/KMZ, XML, Shapefiles, and GRIB into validated, standards-compliant context data.

Datasetobservation.xml

<metData>
  <domain_id>65142878</domain_id>
  <domain_lat>46.0658</domain_lat>
  <domain_lon>14.5172</domain_lon>
  <domain_title>LJUBLJANA/BEZIGRAD</domain_title>
  <valid_UTC>21.08.2026 10:00 UTC</valid_UTC>
  <t>23</t>
</metData>

Mappingweather.json5

{
  version: "v4",
  dataModel: "dataModel.Weather/WeatherObserved",
  identity: {
    entityName: "{{ metData.domain_id }}",
  },
  attributes: {
    temperature: {
      source: "{{ metData.t }}",
      type: "Property",
      transformation: "float",
      properties: {
        unitCode: {
          source: "CEL",
        },
        observedAt: {
          source: "{{ metData.valid_UTC | replace(from='.', to='/') | replace(from=' UTC', to='') }}",
          type: "Property",
          transformation: "datetime",
        },
      },
    },
  },
}

EntityWeatherObserved.json

{
  "id": "urn:ngsi-ld:WeatherObserved:65142878",
  "type": "WeatherObserved",
  "temperature": {
    "type": "Property",
    "value": 23.0,
    "observedAt": "2026-08-21T10:00:00Z",
    "unitCode": "CEL"
  }
}

Surface observation for Ljubljana Bežigrad, trimmed to one reading. Source: Slovenian Environment Agency (ARSO), free reuse with attribution. Example 14 works the full mapping through.

NGSI-LD is the linked-data model used by many smart-city, IoT, and dataspace platforms across Europe. Cassiopeia prepares data for these systems; it does not store or serve context itself.

Sovereignty

The output format determines how easily you can move your data later.

An EU open standard

Cassiopeia writes ETSI NGSI-LD rather than a vendor-specific format, so the output stays readable by anything that speaks the standard.

Your files, your repository

Mappings are plain JSON5 files you keep and version yourself. Output goes to files, or to the NGSI-LD context broker you choose.

Your machines

The FOSS edition runs under the EUPL-1.2 with no account, no licence key, and no telemetry.

SenLab's full position on ownership, export, and reversibility is at velacontext.com/sovereignty.

Editions

Cassiopeia is open core. The FOSS edition is complete on its own: it maps, validates, and delivers NGSI-LD without a licence key or account, and what ships in it stays in it. Pro and Hub add operational tooling around the same engine.

Community

Cassiopeia is not accepting external source-code contributions yet. Bug reports, feature requests, and documentation feedback are welcome.

General contact: info@velacontext.com. Never report a security vulnerability through a public issue — follow the security policy instead.