Vector Tiles (MVT)

Sanson serves Mapbox Vector Tiles (MVT) for each collection, enabling fast map rendering in web applications.

Endpoint

GET /collections/{collectionId}/tiles/{z}/{x}/{y}.pbf

Returns a binary protobuf tile in application/vnd.mapbox-vector-tile format.

• Empty tiles return 204 No Content
• Caching: Cache-Control: public, max-age=3600 (1 hour)

Tileset metadata

GET /collections/{collectionId}/tiles

Returns OGC-compliant tileset metadata for a collection, including the tile matrix set, bounding box, and templated tile URLs.

Tile matrix sets

GET /tileMatrixSets

Lists available tile matrix sets. Sanson supports WebMercatorQuad (EPSG:3857).

GET /tileMatrixSets/WebMercatorQuad

Returns the full WebMercatorQuad definition with all zoom levels (0–24), scale denominators, and matrix dimensions.

Compatible clients

• MapLibre GL JS
• Leaflet (with vector tile plugins)
• QGIS (Vector Tiles layer)
• Any client that supports the MVT format

PostGIS implementation

Tiles are generated on-the-fly using PostGIS:

• ST_AsMVT + ST_AsMVTGeom for tile encoding
• Extent: 4096 (standard tile resolution)
• Buffer: 256 pixels (prevents edge artifacts)
• Coordinate system: Web Mercator (EPSG:3857)
• Spatial filter uses the GIST index via && for performance

Usage with MapLibre GL JS

const map = new maplibregl.Map({
  container: 'map',
  style: {
    version: 8,
    sources: {
      sanson: {
        type: 'vector',
        tiles: ['http://localhost:3000/collections/default:regions/tiles/{z}/{x}/{y}.pbf'],
      },
    },
    layers: [
      {
        id: 'regions-fill',
        type: 'fill',
        source: 'sanson',
        'source-layer': 'regions',
        paint: {
          'fill-color': '#1B4F72',
          'fill-opacity': 0.4,
        },
      },
      {
        id: 'regions-outline',
        type: 'line',
        source: 'sanson',
        'source-layer': 'regions',
        paint: {
          'line-color': '#1B4F72',
          'line-width': 1,
        },
      },
    ],
  },
})

TIP

The source-layer name matches the collection name in Sanson (e.g., regions for a collection named regions).