title: LUIS Bot with Node.js - Tutorial - Web app Bot - Bot Framework SDK 4.0 titleSuffix: Azure Cognitive Services description: Using Node.js, build a chat bot integrated with language understanding (LUIS). This chat bot uses the Human Resources app to quickly implement a bot solution. The bot is built with the Bot Framework version 4 and the Azure Web app bot. services: cognitive-services author: diberry manager: cjgronlund ms.service: cognitive-services ms.component: language-understanding ms.topic: tutorial ms.date: 09/24/2018 ms.author: diberry

Tutorial: LUIS bot in Node.js

Using Node.js, you can build a chat bot integrated with language understanding (LUIS). This bot uses the HomeAutomation app to implement a bot solution. The bot is built the Azure Web app bot with Bot Framework version v4.

In this tutorial, you learn how to:

[!div class="checklist"]

Create a web app bot. This process creates a new LUIS app for you.

Add a prebuilt domain to the new LUIS model

Download the project created by the Web bot service

Start bot & emulator locally on your computer

Modify bot code for new LUIS intents

View utterance results in bot

Prerequisites

Bot emulator
Visual Studio Code

Create web app bot

In the Azure portal, select Create new resource.
In the search box, search for and select Web App Bot. Select Create.

In Bot Service, provide the required information:

Setting	Purpose	Suggested setting
Bot name	Resource name	`luis-nodejs-bot-` + `<your-name>`, for example, `luis-nodejs-bot-johnsmith`
Subscription	Subscription where to create bot.	Your primary subscription.
Resource group	Logical group of Azure resources	Create a new group to store all resources used with this bot, name the group `luis-nodejs-bot-resource-group`.
Location	Azure region - this doesn't have to be the same as the LUIS authoring or publishing region.	`westus`
Pricing tier	Used for service request limits and billing.	`F0` is the free tier.
App name	The name is used as the subdomain when your bot is deployed to the cloud (for example, humanresourcesbot.azurewebsites.net).	`luis-nodejs-bot-` + `<your-name>`, for example, `luis-nodejs-bot-johnsmith`
Bot template	Bot framework settings - see next table
LUIS App location	Must be the same as the LUIS resource region	`westus`

In the Bot template settings, select the following, then choose the Select button under these settings:

Setting Purpose Selection

SDK version Bot framework version SDK v4

SDK language Programming language of bot Node.js

Echo/Basic bot Type of bot Basic bot
Select Create. This creates and deploys the bot service to Azure. Part of this process creates a LUIS app named luis-nodejs-bot-XXXX. This name is based on the bot and app name's in the previous section.
Leave this browser tab open. For any steps with the LUIS portal, open a new browser tab. Continue to the next section when the new bot service is deployed.

Add prebuilt domain to model

Part of the bot service deployment creates a new LUIS app with intents and example utterances. The bot provides intent mapping to the new LUIS app for the following intents:

Basic bot LUIS intents	example utterance
Cancel	`stop`
Greeting	`hello`
Help	`help`
None	Anything outside the domain of the app.

Add the prebuilt HomeAutomation app to the model to handle utterances like: Turn off the living room lights

Go to LUIS portal and sign in.
On the My Apps page, select the Created date column to sort by the date the app was created. The Azure Bot service created a new app in the previous section. Its name is luis-nodejs-bot- + <your-name> + 4 random characters.
Open the app and select the Build section in the top navigation.
From the left navigation, select Prebuilt Domains.
Select the HomeAutomation domain by select Add domain on its card.
Select Train in the top right menu.
Select Publish in the top right menu.

The app created by the Azure Bot service now has new intents:

Basic bot new intents example utterance

HomeAutomation.TurnOn turn the fan to high

HomeAutomation.TurnOff turn off ac please

Download the web app bot

In order to develop the web app bot code, download the code and use on your local computer.

In the Azure portal, still on the web app bot resource, select the Application Settings and copy the values of botFilePath and botFileSecret. You need to add these to an environment file later.
In the Azure portal, select Build from the Bot management section.
Select Download Bot source code.
When the source code is zipped, a message will provide a link to download the code. Select the link.
Save the zip file to your local computer and extract the files. Open the project.

Open the bot.js file and look for const results = await this.luisRecognizer.recognize(context);. This is where the user utterance entered into the bot is sent to LUIS.

/**
 * Driver code that does one of the following:
 * 1. Display a welcome card upon startup
 * 2. Use LUIS to recognize intents
 * 3. Start a greeting dialog
 * 4. Optionally handle Cancel or Help interruptions
 *
 * @param {Context} context turn context from the adapter
 */
async onTurn(context) {
    // Create a dialog context
    const dc = await this.dialogs.createContext(context);

    if(context.activity.type === ActivityTypes.Message) {
        // Perform a call to LUIS to retrieve results for the current activity message.
        const results = await this.luisRecognizer.recognize(context);
        
        const topIntent = LuisRecognizer.topIntent(results);

        // handle conversation interrupts first
        const interrupted = await this.isTurnInterrupted(dc, results);
        if(interrupted) {
            return;
        }

        // Continue the current dialog
        const dialogResult = await dc.continue();

        switch(dialogResult.status) {
            case DialogTurnStatus.empty:
                switch (topIntent) {
                    case GREETING_INTENT:
                        await dc.begin(GREETING_DIALOG);
                        break;

                    case NONE_INTENT:
                    default:
                        // help or no intent identified, either way, let's provide some help
                        // to the user
                        await dc.context.sendActivity(`I didn't understand what you just said to me. topIntent ${topIntent}`);
                        break;
                }

            case DialogTurnStatus.waiting:
                // The active dialog is waiting for a response from the user, so do nothing
            break;

            case DialogTurnStatus.complete:
                await dc.end();
                break;

            default:
                await dc.cancelAll();
                break;

        }

    } else if (context.activity.type === 'conversationUpdate' && context.activity.membersAdded[0].name === 'Bot') {
        // When activity type is "conversationUpdate" and the member joining the conversation is the bot
        // we will send our Welcome Adaptive Card.  This will only be sent once, when the Bot joins conversation
        // To learn more about Adaptive Cards, see https://aka.ms/msbot-adaptivecards for more details.
        const welcomeCard = CardFactory.adaptiveCard(WelcomeCard);
        await context.sendActivity({ attachments: [welcomeCard] });
    }
}

The bot sends the user's utterance to LUIS and gets the results. The top intent determines the conversation flow.

Start the bot

Before changing any code or settings, verify the bot works.

In Visual Studio Code, open a terminal window.
Install the npm dependencies for this bot.
```
npm install
```
Create a file to hold the environment variables the bot code looks for. Name the file .env. Add the following environment variables:
```
botFilePath=
botFileSecret=
```
Set the values of the environment variables to the values you copied from the Azure bot service's Application Settings in Step 1 of the Download the web app bot section.
Start the bot in watch mode. Any changes you make to the code after this start will cause an automatic restart of the app.
```
npm run watch
```

When the bot starts up, the terminal window displays the local port the bot is running on:

> basic-bot@0.1.0 start C:\Users\pattiowens\repos\BFv4\luis-nodejs-bot-src
> node ./index.js NODE_ENV=development

restify listening to http://[::]:3978

Get the Emulator: https://aka.ms/botframework-emulator

To talk to your bot, open the luis-nodejs-bot-pattiowens.bot file in the Emulator

Start the emulator

Begin the Bot Emulator.
In the bot emulator, select the *.bot file in the root of the project. This .bot file includes the bot's URL endpoint for messages:
Enter the bot secret you copied from the Azure bot service's Application Settings in Step 1 of the Download the web app bot section. This allows the emulator to access any encrypted fields in the .bot file.
In the bot emulator, enter Hello and get the proper response for the basic bot.

Modify bot code

In the bot.js file, add code to handle the new intents.

At the top of the file, find the Supported LUIS Intents section, and add constants for the HomeAutomation intents:

// Supported LUIS Intents
const GREETING_INTENT = 'Greeting';
const CANCEL_INTENT = 'Cancel';
const HELP_INTENT = 'Help';
const NONE_INTENT = 'None';
const TURNON_INTENT = 'HomeAutomation_TurnOn'; // new intent
const TURNOFF_INTENT = 'HomeAutomation_TurnOff'; // new intent

Notice that the period, ., between the domain and the intent from the LUIS portal's app is replaced with an underscore, _.

Find the isTurnInterrupted that receives the LUIS prediction of the utterance and add a line to print out the result to the console.

/**
 * Look at the LUIS results and determine if we need to handle
 * an interruptions due to a Help or Cancel intent
 *
 * @param {DialogContext} dc - dialog context
 * @param {LuisResults} luisResults - LUIS recognizer results
 */
async isTurnInterrupted(dc, luisResults) {
    console.log(JSON.stringify(luisResults));
...

The bot doesn't have the exact same response as a LUIS REST API request so it is important to learn the differences by looking at the response JSON. The text and intents properties are the same but the entities property values have been modified.

{
    "$instance": {
        "HomeAutomation_Device": [
            {
                "startIndex": 23,
                "endIndex": 29,
                "score": 0.9776345,
                "text": "lights",
                "type": "HomeAutomation.Device"
            }
        ],
        "HomeAutomation_Room": [
            {
                "startIndex": 12,
                "endIndex": 22,
                "score": 0.9079433,
                "text": "livingroom",
                "type": "HomeAutomation.Room"
            }
        ]
    },
    "HomeAutomation_Device": [
        "lights"
    ],
    "HomeAutomation_Room": [
        "livingroom"
    ]
}

Add the intents to the onTurn method's switch statement for the DialogTurnStatus.empty case:

switch (topIntent) {
    case GREETING_INTENT:
        await dc.begin(GREETING_DIALOG);
        break;

    // New HomeAutomation.TurnOn intent
    case TURNON_INTENT: 

        await dc.context.sendActivity(`TurnOn intent found, entities included: ${JSON.stringify(results.entities)}`);
        break;

    // New HomeAutomation.TurnOff intent
    case TURNOFF_INTENT: 

        await dc.context.sendActivity(`TurnOff intent found, entities included: ${JSON.stringify(results.entities)}`);
        break;

    case NONE_INTENT:
    default:
        // help or no intent identified, either way, let's provide some help
        // to the user
        await dc.context.sendActivity(`I didn't understand what you just said to me. topIntent ${topIntent}`);
        break;
}

View results in bot

In the bot emulator, enter the utterance: Turn on the livingroom lights to 50%

The bot responds with:

TurnOn intent found, entities included: {"$instance":{“HomeAutomation_Device”:[{“startIndex”:23,“endIndex”:29,“score”:0.9776345,“text”:“lights”,“type”:“HomeAutomation.Device”}],“HomeAutomation_Room”:[{“startIndex”:12,“endIndex”:22,“score”:0.9079433,“text”:“livingroom”,“type”:“HomeAutomation.Room”}]},“HomeAutomation_Device”:[“lights”],“HomeAutomation_Room”:[“livingroom”]}

Learn more about Bot Framework

Azure Bot service uses the Bot Framework SDK. Learn more about the SDK and bot framework:

Azure Bot Service v4 documentation
Bot Builder Samples
Bot Builder SDK
Bot Builder tools:

Next steps

You created an Azure bot service, copied the bot secret and .bot file path, downloaded the zip file of the code. You added the prebuilt HomeAutomation domain to the LUIS app created as part of the new Azure bot service, then trained and published the app again. You extracted the code project, created an environment file (.env), and set the bot secret and the .bot file path. In the bot.js file, you added code to handle the two new intents. Then you tested the bot in the bot emulator to see the LUIS response for an utterance of one of the new intents.

[!div class="nextstepaction"] Build a custom domain in LUIS

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luis-nodejs-tutorial-bf-v4.md

luis-nodejs-tutorial-bf-v4.md

Tutorial: LUIS bot in Node.js

Prerequisites

Create web app bot

Add prebuilt domain to model

Download the web app bot

Start the bot

Start the emulator

Modify bot code

View results in bot

Learn more about Bot Framework

Next steps

Setting	Purpose	Selection
SDK version	Bot framework version	SDK v4
SDK language	Programming language of bot	Node.js
Echo/Basic bot	Type of bot	Basic bot

Basic bot new intents	example utterance
HomeAutomation.TurnOn	`turn the fan to high`
HomeAutomation.TurnOff	`turn off ac please`

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luis-nodejs-tutorial-bf-v4.md

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Tutorial: LUIS bot in Node.js

Prerequisites

Create web app bot

Add prebuilt domain to model

Download the web app bot

Start the bot

Start the emulator

Modify bot code

View results in bot

Learn more about Bot Framework

Next steps