# Cluster Document

## Purpose
Aggregated point or object clusters with summary attributes for efficient visualization.

## GeoJSON (DB metadata)
```json
{
  "type": "Feature",
  "geometry": {"type": "Point", "coordinates": [30.15, 59.95]},
  "properties": {
    "type": "Cluster",
    "title": "Detections Cluster (k=8)",
    "created_at": "2025-04-10T10:00:00Z",
    "updated_at": "2025-04-10T10:00:00Z",
    "source": {
      "url": "/s3/<bucket>/<ResultKey>/<filename>",
      "type": "GeoJSON"
    },
    "summary": {"count": 128, "mean_score": 0.87},
    "style": {"marker": "circle", "color": "#ff0000"}
  }
}
```

## Required properties
- `properties.type` = `Cluster`
- Centroid point geometry (or cluster hull polygon)
- Summary attributes for counts and statistics

## Publishing workflow
1. Compute clusters and summary statistics.
2. Save JSON/GeoJSON payload and upload.
3. Publish Feature with type `Cluster` linking via `properties.source.url`.

## Validation checklist
- Summary fields match the underlying members.
- Styling communicates cluster size or score.

See [Common properties](../common.md) for shared fields like legend, metadata, and classification.
See also: [GeoJSON Strategy](../../Geojson_strategy.md) and [Upload Strategy](../../Upload_strategy.md).