Specify API Key For Google Matrix API Javascript To Retrieve Usage

Question

i am using google matrix API successfully to retrieve the time and distance for location a to location b.

var origins = [Task.getItem("Y") + "," + Task.getItem("X")];
            var destinations = [LAT + "," + LNG];

            var distanceMatrix = new google.maps.DistanceMatrixService();
            var distanceRequest = {
                origins: origins,
                destinations: destinations,
                travelMode: google.maps.TravelMode.DRIVING,
                unitSystem: google.maps.UnitSystem.METRIC,
                avoidHighways: false,
                avoidTolls: false
            };
            distanceMatrix.getDistanceMatrix(distanceRequest, function(response, status) {
                if (status != google.maps.DistanceMatrixStatus.OK) {
                    alert('Error was: ' + status);
                } else {
                    var origins = response.originAddresses;
                    var destinations = response.destinationAddresses;
                    //debugger;
                    if (response.rows[0].elements[0].distance != null) {
                        totalDistance = response.rows[0].elements[0].distance.value;
                        totalTime = response.rows[0].elements[0].duration.value;
                        ratioPerOneMeter = totalDistance / totalTime;
                        PRDifference = 0;

                        updateDistanceAndTime();

                    } else {
                        alert("The Distance And Time Cannot Be Calculated");
                    }
                }
            });

What I want to do is add the API key but I don't know how. I did add in the API key:

<script src="http://maps.googleapis.com/maps/api/js?key={KEY}&v=3.exp">

as stated here: Using a Google Apps API key with Distance Matrix

but I think this is just for the map and not for the matrix API. Can someone inform me if this is enough.

Answer 1

The Google Maps Distance Matrix Service in the Google Maps Javascript API uses the key provided in the API include.

<script src="http://maps.googleapis.com/maps/api/js?key={KEY}">

That usage is not tracked separately in the developer console. The usage tracked under "Google Maps Distance Matrix API" is the usage of the Web Service only.