In order to communicate with your own GraphHopper server or a hosted one you need to understand how to use it. There is a separate JavaScript and Java client for this API or you use the plain JSON response for a different language.

To find out how to use the hosted GraphHopper Directions API you should refer to the online documentation here.

This file here describes the web API of the open source routing server.

http://localhost:8989/route?point=52.5300591%2C13.3565022&point=52.5060440%2C13.4378107

The URL path of the local instance is http://localhost:8989

The endpoint to obtain the route is /route via GET.

The GET request has an URL length limitation, so it won't work for many locations per request. In those cases use a HTTP POST request with JSON data as input. The POST request is identical except that all singular parameter names are named as their plural for a POST request. All effected parameters are: points, snap_preventions, curbsides and point_hints. (details stays details)

Please note that unlike to the GET endpoint, points are specified in [longitude, latitude] order. For example point=10,11&point=20,22 will be the following JSON:

{ "points": [[11,10], [22,20]] }

All official parameters are shown in the following table

If you enabled hybrid mode in the config you can use most of the features from flexible mode and still benefit from a speed up.

Unlock certain flexible features via ch.disable=true per request or disable CH on the server-side by using an empty list for profiles_ch. The only exception is the parameter algorithm=alternative_route which is also available without specifying ch.disable=true.

Only applicable when profile pt is used.

Keep in mind that attributes which are not documented here can be removed in the future - you should not rely on them! The JSON result contains the following structure:

{
  "paths": [{
    "bbox": [
      13.362853824187303,
      52.469481955531585,
      13.385836736460217,
      52.473849308838446
    ],
    "distance": 2138.3027624572337,
    "instructions": [
      {
        "distance": 1268.519329705091,
        "interval": [
          0,
          10
        ],
        "sign": 0,
        "text": "Geradeaus auf A 100",
        "time": 65237
      },
      {
        "distance": 379.74399999999997,
        "interval": [
          10,
          11
        ],
        "sign": 0,
        "text": "Geradeaus auf Strasse",
        "time": 24855
      },
      {
        "distance": 16.451,
        "interval": [
          11,
          11
        ],
        "sign": 0,
        "text": "Geradeaus auf Tempelhofer Damm",
        "time": 1316
      },
      {
        "distance": 473.58843275214315,
        "interval": [
          11,
          12
        ],
        "sign": -2,
        "text": "Links abbiegen auf Tempelhofer Damm, B 96",
        "time": 37882
      },
      {
        "distance": 0,
        "interval": [
          12,
          12
        ],
        "sign": 4,
        "text": "Ziel erreicht!",
        "time": 0
      }
    ],
    "points": "oxg_Iy|ppAl@wCdE}LfFsN|@_Ej@eEtAaMh@sGVuDNcDb@{PFyGdAi]FoC?q@sXQ_@?",
    "points_encoded": true,
    "details":{
        "street_name":[[0,1,"Rue Principale"],[1,13,"D19E"],[13,18,"D19"],..]
    },
    "time": 129290
  }]
}

If you need to find out details about the area or need to ping the service use '/info'

http://localhost:8989/info

{ "build_date":"2023-02-21T16:52",
  "bbox":[13.072624,52.333508,13.763972,52.679616],
  "version":"8.0",
  "elevation": false,
  "profiles": [{
    "name": "foot",
  }],
  ...
}

{
  "message": "Cannot find point 2: 2248.224673, 3.867187",
  "hints": [{"message": "something", ...}]
}

Sometimes a point can be "off the road" and you'll get 'cannot find point', this normally does not indicate a bug in the routing engine and is expected to a certain degree if too far away.

In addition to routing, the end point to obtain an isochrone is /isochrone. To get a point list instead of a polygon you can have a look into the /spt endpoint.

http://localhost:8989/isochrone

All parameters are shown in the following table.