Isochrone

Compute the geographic area reachable from a point in N minutes or N kilometers. Returned as GeoJSON Polygon.

The Isochrone endpoint computes the reachable area from an origin within a given time (in minutes) or distance (in kilometers). The result is a GeoJSON polygon ready to render on a map.

Endpoint

POST https://api.tmaps.tn/routing/isochrone?api_key=YOUR_API_KEY

Parameters

JSON body

Param	Type	Requis	Défaut	Description
`origin`	object	oui	—	Starting point `{ lat, lng }`.
`contours`	array	oui	—	List of contours to compute. Each contour is `{ time: minutes }` or `{ distance: km }`. Multiple contours can be requested in a single call.
`profile`	string	—	`driving`	Transport profile: `driving`, `walking`, `cycling`, `truck`.
`colors`	array	—	—	HTML color (hex) per contour to ease rendering (e.g. `['#22c55e', '#f59e0b', '#ef4444']`).

Limits

Max time: 60 minutes per contour.
Max distance: 50 km per contour.
Max contours: 4 per request (for stacked isochrones).

Example — 15-min driving catchment area

curl -X POST "https://api.tmaps.tn/routing/isochrone?api_key=YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
  "origin":   { "lat": 36.8002, "lng": 10.1815 },
  "contours": [{ "time": 15 }],
  "profile":  "driving"
}'

Example — stacked isochrones (5 / 10 / 15 min)

const res = await fetch(
'https://api.tmaps.tn/routing/isochrone?api_key=YOUR_API_KEY',
{
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    origin: { lat: 36.8002, lng: 10.1815 },
    contours: [
      { time: 5 },
      { time: 10 },
      { time: 15 },
    ],
    profile: 'driving',
    colors: ['#22c55e', '#f59e0b', '#ef4444'],
  }),
}
);
const geojson = await res.json();
// → 3 features in the FeatureCollection

Response

The response is a GeoJSON FeatureCollection with one feature per requested contour, in the same order as the request.

{
"type": "FeatureCollection",
"features": [
  {
    "type": "Feature",
    "properties": {
      "contour": 15,
      "metric": "time",
      "color": "#22c55e"
    },
    "geometry": {
      "type": "Polygon",
      "coordinates": [[
        [10.0801, 36.8412],
        [10.1240, 36.8650],
        [10.2308, 36.8580],
        [10.2620, 36.8011],
        [10.2210, 36.7530],
        [10.1100, 36.7480],
        [10.0801, 36.8412]
      ]]
    }
  }
]
}

Returned fields

Feature properties

Param	Type	Requis	Défaut	Description
`contour`	number	—	—	Contour value: number of minutes or kilometers.
`metric`	string	—	—	`time` or `distance` depending on the request.
`color`	string	—	—	Color associated with the contour, if provided in input. Convenient to style the map layer directly.

Render order

When requesting multiple stacked contours, draw the largest (15 min) at the back and the smallest (5 min) on top to get nice concentric rings.

Use cases

Geomarketing & retail: catchment areas to open a new store.
Real estate: show “all schools within 10 minutes’ walk of this property”.
Logistics: areas serviceable by a depot in under 30 minutes.
Emergency services: 5-min coverage of a fire station / hospital.

Errors

Status	Cause
`400`	Missing `origin`, `time > 60` or `distance > 50`
`401`	Missing or revoked `api_key`
`403`	Domain not authorized
`404`	Origin outside coverage

See Error codes for the full list.