Is it possible to use AMAZON LEX to build a chatbot which connects with database and Web service stored on client side?

Question

Our organization wants to develop a \"LOST & FOUND System Application\" using chatbot integrated in a website.

Whenever the user starts the conver

Answer 1

As someone who just implemented this very same situation (with a lot of help from @Sid8491), I can give some insight on how I managed it.

Note, I'm using C# because that's what the company I work for uses.

First, the bot requires input from the user to decide what intent is being called. For this, I implemented a PostText call to the Lex API.

PostTextRequest lexTextRequest = new PostTextRequest()
        {
            BotName = botName,
            BotAlias = botAlias,
            UserId = sessionId,
            InputText = messageToSend
        };

        try
        {
            lexTextResponse = await awsLexClient.PostTextAsync(lexTextRequest);
        }
        catch (Exception ex)
        {
            throw new BadRequestException(ex);
        }

Please note that this requires you to have created a Cognito Object to authenticate your AmazonLexClient (as shown below):

protected void InitLexService()
    {
        //Grab region for Lex Bot services
        Amazon.RegionEndpoint svcRegionEndpoint = Amazon.RegionEndpoint.USEast1;

        //Get credentials from Cognito
        awsCredentials = new CognitoAWSCredentials(
                            poolId,                     // Identity pool ID
                            svcRegionEndpoint);         // Region

        //Instantiate Lex Client with Region
        awsLexClient = new AmazonLexClient(awsCredentials, svcRegionEndpoint);
    }

After we get the response from the bot, we use a simple switch case to correctly identify the method we need to call for our web application to run. The entire process is handled by our web application, and we use Lex only to identify the user's request and slot values.

//Call Amazon Lex with Text, capture response
var lexResponse = await awsLexSvc.SendTextMsgToLex(userMessage, sessionID);

//Extract intent and slot values from LexResponse
string intent = lexResponse.IntentName;
var slots = lexResponse.Slots;

//Use LexResponse's Intent to call the appropriate method 
switch (intent)
{
    case: /*Your intent name*/:
    /*Call appropriate method*/;
    break;
}

After that, it is just a matter of displaying the result to the user. Do let me know if you need more clarification!

UPDATE:

An example implementation of the slots data to write to SQL (again in C#) would look like this:

 case "LostItem":                                              
      message = "Please fill the following form with the details of the item you lost.";
      LostItem();
      break;

This would then take you to the LostItem() method which you can use to fill up a form.

public void LostItem()
{
    string itemName = string.Empty;
    itemName = //Get from user
    //repeat with whatever else you need for a complete item object

    //Implement a SQL call to a stored procedure that inserts the object into your database. 
    //You can do a similar call to the database to retrieve an object as well
}

That should point you in the right direction hopefully. Google is your best friend if you need help with SQL stored procedures. Hopefully this helped!

Answer 2

Yes its possible.

You can send the requests to Lex from your website which will extract Intents and Entities.
Once you get these, you can write backend code in any language of your choice and use any DB you want.
In your use case, you might just want to use Lex. PostText will be main function you will be calling.

You will need to create an intent in Lex which will have multiple slots LosingDate, LosingPlace or whatever you want, then it will be able to get all these information from the user and pass it to your web application.