Adding extra fields to GeoJSON

Question

My app returns standard GeoJSON, always as a FeatureCollection.

When I display the GeoJSON in my front end, I want to zoom to show just the features in the file. I'd like to include an enclosing boundary box to make that easier:

{
    "boundaries": [12.3456, 78.9012, 34.5678, 90.1234],
    "type": "FeatureCollection",
    "features": [{
        "type": "Feature",
        "properties": {
            "name": "value"
        },
        "geometry": {
            "type": "Point",
            "coordinates": [...]
        }
    }]
}

Is it acceptable to non-standard fields like this? Is this valid GeoJSON or will third-party tools choke on it?

Answer 1

The standard already allows you to add a bbox inside the feature collection.

A GeoJSON object MAY have a member named "bbox" to include information on the coordinate range for its Geometries, Features, or FeatureCollections.