Distance to nearest point on segment API

Finds the nearest point on a finite great-circle segment to a query point, returning the distance, the nearest coordinate, the parametric position t (0..1), and whether the foot of the perpendicular is clamped to an endpoint. Answers 'What is the closest point on this line segment?', 'How far is this point from a finite path edge?'.

Price$0.06per request

MethodPOST

Route/v1/geo/point-to-segment

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

geogispoint-to-segmentnearest-pointdistanceprojectionsnap-to-linepolylinerouting

API URLhttps://x402.hexl.dev/v1/geo/point-to-segment

Integration docs

Example request

{
  "point": {
    "latitude": 51,
    "longitude": 1
  },
  "segStart": {
    "latitude": 51.5074,
    "longitude": -0.1278
  },
  "segEnd": {
    "latitude": 48.8566,
    "longitude": 2.3522
  }
}

Example response

{
  "point": {
    "latitude": 51,
    "longitude": 1
  },
  "segStart": {
    "latitude": 51.5074,
    "longitude": -0.1278
  },
  "segEnd": {
    "latitude": 48.8566,
    "longitude": 2.3522
  },
  "nearestPoint": {
    "latitude": 50.815628,
    "longitude": 0.519399
  },
  "distanceKm": 39.444204,
  "distanceMeters": 39444.204,
  "t": 0.260967,
  "clamped": "interior",
  "interpretation": "Nearest point on the segment is 39.444 km away at parameter t=0.261 (an interior point)."
}

Input schema

{
  "type": "object",
  "required": [
    "point",
    "segStart",
    "segEnd"
  ],
  "properties": {
    "point": {
      "type": "object",
      "properties": {
        "latitude": {
          "type": "number"
        },
        "longitude": {
          "type": "number"
        }
      },
      "examples": [
        {
          "latitude": 51,
          "longitude": 1
        }
      ]
    },
    "segStart": {
      "type": "object",
      "properties": {
        "latitude": {
          "type": "number"
        },
        "longitude": {
          "type": "number"
        }
      },
      "examples": [
        {
          "latitude": 51.5074,
          "longitude": -0.1278
        }
      ]
    },
    "segEnd": {
      "type": "object",
      "properties": {
        "latitude": {
          "type": "number"
        },
        "longitude": {
          "type": "number"
        }
      },
      "examples": [
        {
          "latitude": 48.8566,
          "longitude": 2.3522
        }
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}