## Calculate an isochrone from a point

`routing.isochrone_post(**kwargs) -> RoutingIsochronePostResponse`

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

Calculate an isochrone from a point

### Parameters

- `lat: Float`

  Latitude

- `lng: Float`

  Longitude

- `time: Float`

  Travel time in seconds (1-7200)

- `format_: String`

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

- `mode: String`

  Travel mode (auto, foot, bicycle)

- `output_fields: String`

  Comma-separated property fields to include

- `output_geometry: bool`

  Include geometry (default true)

- `output_include: String`

  Extra computed fields: bbox, center

- `output_precision: Integer`

  Coordinate decimal precision (1-15, default 7)

- `output_simplify: Float`

  Simplify geometry tolerance in meters

### Returns

- `class RoutingIsochronePostResponse`

  GeoJSON Feature or FeatureCollection representing isochrone polygons — areas reachable within the specified travel time(s). Single time value returns a Feature; comma-separated times return a FeatureCollection with one polygon per contour.

  - `features: Array[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[Float] | Array[Array[Float]] | Array[Array[Array[Float]]] | Array[Array[Array[Array[Float]]]]`

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

        - `Array[Float]`

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

        - `Array[Array[Float]]`

          Array of [lng, lat] positions

        - `Array[Array[Array[Float]]]`

          Array of linear rings / line strings

        - `Array[Array[Array[Array[Float]]]]`

          Array of polygons

      - `type: :Point | :LineString | :Polygon | 3 more`

        Geometry type

        - `:Point`

        - `:LineString`

        - `:Polygon`

        - `:MultiPoint`

        - `:MultiLineString`

        - `:MultiPolygon`

    - `properties: Hash[Symbol, untyped]`

      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: String`

      Compound identifier in `type/osm_id` format

  - `geometry: GeoJsonGeometry`

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

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

    Isochrone metadata

    - `area_m2: Float`

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

    - `max_cost_s: Float`

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

    - `mode: :auto | :foot | :bicycle`

      Travel mode used for the isochrone calculation

      - `:auto`

      - `:foot`

      - `:bicycle`

    - `time_seconds: Float`

      Travel time budget in seconds

    - `vertices_reached: Integer`

      Number of road network vertices within the isochrone

  - `type: :Feature | :FeatureCollection`

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

    - `:Feature`

    - `:FeatureCollection`

### Example

```ruby
require "plaza"

plaza = Plaza::Client.new(
  api_key: "My API Key",
  environment: "local" # defaults to "production"
)

response = plaza.routing.isochrone_post(lat: 0, lng: 0, time: 0)

puts(response)
```

#### 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"
}
```