How to keep the context of a conversion with amazon lex?

Question

How can I keep the context of a conversation in amazon lex, I read on using session attributes but I did not find any samples.

Here is an example of how I want the conversation to go:

Temperature Intent:

Human: What is the temperature in New York?

Bot: The temperature in New York is 3 degrees Celsius

HumidityIntent:

Human: What about the Humidity?

Bot: The Humidity in New York is 61%

How can I make the bot know that I'm talking about New York when I ask for Humidity?

Answer 1

Since you didn't specify which language you're using, I'm gonna respond using C# (which is what I used).

Conversation context is achieved via the use of Session Attributes. In the case of C#, the easiest way to achieve this is by using AWS Lambda functions. Here's the example provided by Amazon itself (using the BookTrip blueprint for Amazon Lex):

        // Extract slots from Lex Event
        var slots = lexEvent.CurrentIntent.Slots;

        // Extract Session Attributes if they exist, otherwise create new Dictionary
        var sessionAttributes = lexEvent.SessionAttributes ?? new Dictionary<string, string>();

        Reservation lastConfirmedReservation = null;

        // if previous Reservation from Session Attributes exists
        if (slots.ContainsKey(LAST_CONFIRMED_RESERVATION_SESSION_ATTRIBUTE))
        {
            lastConfirmedReservation = DeserializeReservation(slots[LAST_CONFIRMED_RESERVATION_SESSION_ATTRIBUTE]);
        }

        string confirmationContext = sessionAttributes.ContainsKey("confirmationContext") ? sessionAttributes["confirmationContext"] : null;

        if (lastConfirmedReservation != null &&
                        string.Equals(lastConfirmedReservation.ReservationType, "Hotel", StringComparison.Ordinal))
        {
            // If there was a previous reservation - auto-populate to match
            sessionAttributes["confirmationContext"] = "AutoPopulate";
            return ConfirmIntent(
                                sessionAttributes,
                                lexEvent.CurrentIntent.Name,
                                new Dictionary<string, string>
                                {
                                    {PICK_UP_CITY_SLOT, lastConfirmedReservation.PickUpCity },
                                    {PICK_UP_DATE_SLOT, lastConfirmedReservation.CheckInDate },
                                    {RETURN_DATE_SLOT, DateTime.Parse(lastConfirmedReservation.CheckInDate).AddDays(int.Parse(lastConfirmedReservation.Nights)).ToUniversalTime().ToString(CultureInfo.InvariantCulture) },
                                    {CAR_TYPE_SLOT, null },
                                    {DRIVER_AGE_SLOT, null },
                                },
                                new LexResponse.LexMessage
                                {
                                    ContentType = MESSAGE_CONTENT_TYPE,
                                    Content = $"Is this car rental for your {lastConfirmedReservation.Nights} night stay in {lastConfirmedReservation.Location} on {lastConfirmedReservation.CheckInDate}?"
                                }
                              );
        }

The best way to understand how this works is to go through the relevant Blueprint for your language of choice. Hopefully this helped you!

Edit: Additional reading on the Blueprints that are available that may be useful for you. More details on the information flow when using Session Attributes in Lex.