## Calculate an isochrone from a point

**post** `/api/v1/isochrone`

Calculate an isochrone from a point

### Query Parameters

- `lat: number`

  Latitude

- `lng: number`

  Longitude

- `time: number`

  Travel time in seconds (1-7200)

- `format: optional string`

  Response format: json (default), geojson, csv, ndjson

- `mode: optional string`

  Travel mode (auto, foot, bicycle)

- `"output[fields]": optional string`

  Comma-separated property fields to include

- `"output[geometry]": optional boolean`

  Include geometry (default true)

- `"output[include]": optional string`

  Extra computed fields: bbox, center

- `"output[precision]": optional number`

  Coordinate decimal precision (1-15, default 7)

- `"output[simplify]": optional number`

  Simplify geometry tolerance in meters

### Returns

- `features: optional array of GeoJsonFeature`

  Array of isochrone polygon Features (multi-contour only)

  - `geometry: GeoJsonGeometry`

    GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints.

    - `coordinates: array of number or array of array of number or array of array of array of number or array of array of array of array of number`

      Coordinates array. Nesting depth varies by geometry type: Point = [lng, lat], LineString = [[lng, lat], ...], Polygon = [[[lng, lat], ...], ...], etc.

      - `Point = array of number`

        [longitude, latitude] or [longitude, latitude, elevation]

      - `LineStringOrMultiPoint = array of array of number`

        Array of [lng, lat] positions

      - `PolygonOrMultiLineString = array of array of array of number`

        Array of linear rings / line strings

      - `MultiPolygon = array of array of array of array of number`

        Array of polygons

    - `type: "Point" or "LineString" or "Polygon" or 3 more`

      Geometry type

      - `"Point"`

      - `"LineString"`

      - `"Polygon"`

      - `"MultiPoint"`

      - `"MultiLineString"`

      - `"MultiPolygon"`

  - `properties: map[unknown]`

    OSM tags flattened as key-value pairs, plus `@type` (node/way/relation) and `@id` (OSM ID) metadata fields. May include `distance_m` for proximity queries.

  - `type: "Feature"`

    Always `Feature`

    - `"Feature"`

  - `id: optional string`

    Compound identifier in `type/osm_id` format

- `geometry: optional GeoJsonGeometry`

  GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints.

- `properties: optional object { area_m2, max_cost_s, mode, 2 more }`

  Isochrone metadata

  - `area_m2: optional number`

    Area of the isochrone polygon in square meters (multi-contour features only)

  - `max_cost_s: optional number`

    Maximum actual travel cost in seconds to the isochrone boundary (single contour only)

  - `mode: optional "auto" or "foot" or "bicycle"`

    Travel mode used for the isochrone calculation

    - `"auto"`

    - `"foot"`

    - `"bicycle"`

  - `time_seconds: optional number`

    Travel time budget in seconds

  - `vertices_reached: optional number`

    Number of road network vertices within the isochrone

- `type: optional "Feature" or "FeatureCollection"`

  `Feature` for single contour, `FeatureCollection` for multiple contours

  - `"Feature"`

  - `"FeatureCollection"`

### Example

```http
curl https://plaza.fyi/api/v1/isochrone \
    -X POST \
    -H "Authorization: Bearer $PLAZA_API_KEY"
```

#### Response

```json
{
  "features": [
    {
      "geometry": {
        "coordinates": [
          2.3522,
          48.8566
        ],
        "type": "Point"
      },
      "properties": {
        "@id": "bar",
        "@type": "bar",
        "amenity": "bar",
        "cuisine": "bar",
        "name": "bar"
      },
      "type": "Feature",
      "id": "node/21154906"
    }
  ],
  "geometry": {
    "coordinates": [
      2.3522,
      48.8566
    ],
    "type": "Point"
  },
  "properties": {
    "area_m2": 0,
    "max_cost_s": 0,
    "mode": "auto",
    "time_seconds": 0,
    "vertices_reached": 0
  },
  "type": "Feature"
}
```