Every vector source can be previewed instantly — even if you never authored a style.json for it. When you request GET /styles/{id}/style.json and no [[styles]] entry matches {id}, but a vector source with that id exists, tileserver-rs generates a complete MapLibre GL v8 style on the fly.

When it triggers

What the generated style looks like

For each entry in the source's TileJSON vector_layers, three paint layers are emitted so that any geometry renders regardless of what the layer contains:

• a fill layer filtered to ["==", "$type", "Polygon"]
• a line layer filtered to ["==", "$type", "LineString"]
• a circle layer filtered to ["==", "$type", "Point"]

The $type filter collapses Multi* geometries to their singular form, so the three filters together cover every feature.

Layers are grouped all fills → all lines → all circles across source-layers so polygons never paint over points. Each source-layer gets a deterministic color (a stable hue derived from a hash of the layer id), with fill-outline-color always set and zoom-interpolated line-width / circle-radius.

Empty or missing vector_layers still yields a valid style with a single background layer — the viewer renders a blank map rather than erroring.

Example

curl -s http://localhost:8080/styles/protomaps/style.json | jq '.version, (.layers | length)'
# 8
# 10   (background + 3 kinds × 3 source-layers)

The generated style points its source at the TileJSON endpoint (/data/{id}.json). Any ?key= query is forwarded to that URL and to the glyphs URL. MLT sources emit inline .pbf tiles because maplibre-gl-js cannot decode MLT directly.

Providing your own style

To fully control the appearance, add a [[styles]] entry — it always takes precedence over auto-generation:

[[styles]]
id = "protomaps"
path = "/data/styles/protomaps/style.json"
name = "Protomaps"