Tutorial: Call a LUIS endpoint using JavaScript

Pass utterances to a LUIS endpoint and get intent and entities back.

  • Create LUIS subscription and copy key value for later use
  • View LUIS endpoint results from browser to public sample IoT app
  • Create Visual Studio C# console app to make HTTPS call to LUIS endpoint

For this article, you need a free LUIS account in order to author your LUIS application.

Create LUIS subscription key

You need a Cognitive Services API key to make calls to the sample LUIS app used in this walkthrough.

To get an API key, follow these steps:

  1. You first need to create a Cognitive Services API account in the Azure portal. If you don't have an Azure subscription, create a free account before you begin.

  2. Log in to the Azure portal at https://portal.azure.com.

  3. Follow the steps in Creating Subscription Keys using Azure to get a key.

  4. Go back to the LUIS website and log in using your Azure account.

Understand what LUIS returns

To understand what a LUIS app returns, you can paste the URL of a sample LUIS app into a browser window. The sample app is an IoT app that detects whether the user wants to turn on or turn off lights.

  1. The endpoint of the sample app is in this format: https://westus.api.cognitive.microsoft.com/luis/v2.0/apps/df67dcdb-c37d-46af-88e1-8b97951ca1c2?subscription-key=<YOUR_API_KEY>&verbose=false&q=turn%20on%20the%20bedroom%20light. Copy the URL and substitute your subscription key for the value of the subscription-key field.

  2. Paste the URL into a browser window and press Enter. The browser displays a JSON result that indicates that LUIS detects the HomeAutomation.TurnOn intent and the HomeAutomation.Room entity with the value bedroom.

    JSON result detects the intent TurnOn

  3. Change the value of the q= parameter in the URL to turn off the living room light, and press enter. The result now indicates that the LUIS detected the HomeAutomation.TurnOff intent and the HomeAutomation.Room entity with value living room.

    JSON result detects the intent TurnOff

Consume a LUIS result using the Endpoint API with JavaScript

You can use JavaScript to access the same results you saw in the browser window in the previous step.

  1. Copy the code that follows and save it into an HTML file:

    <!DOCTYPE html>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
    <script type="text/javascript">
        $(function() {
            var params = {
                // These are optional request parameters. They are set to their default values.
                "timezoneOffset": "0",
                "verbose": "false",
                "spellCheck": "false",
                "staging": "false",
                url: "https://westus.api.cognitive.microsoft.com/luis/v2.0/apps/df67dcdb-c37d-46af-88e1-8b97951ca1c2?q=turn%20on%20the%20left%20light" + $.param(params),
                beforeSend: function(xhrObj){
                    // Request headers
                type: "GET",
                // The request body may be empty for a GET request
                data: "{body}",
            .done(function(data) {
                // Display a popup containing the top intent
                alert("Detected the following intent: " + data.topScoringIntent.intent);
            .fail(function() {
  2. Replace "YOUR SUBSCRIPTION KEY" with your subscription key in this line of code: xhrObj.setRequestHeader("Ocp-Apim-Subscription-Key","YOUR SUBSCRIPTION KEY");

  3. Open the file you saved using a web browser. An alert window should pop up that says Detected the following intent: TurnOn.

Popup that says TurnOn

Clean up resources

The two resources created in this tutorial are the LUIS subscription key and the C# project. Delete the LUIS subscription key from the Azure portal. Close the Visual Studio project and remove the directory from the file system.

Next steps