Differences between using Lex and Alexa

Question

I'm building an Alexa skill that will allow Alexa users to interact with a consumer facing e-commerce site. There is functionality to call a representative that already exists on the site. Now, I want to build out a voice app as a side project that extends that same option via a conversation. There will be a need for slots like location, category of call, etc. It's basically an Application/Transactional bot.

In the future, if this is successful, I'd like that same general app to be accessible on different IoT devices (like Google Home Assistant, etc.) Therefore, I'd like to abstract out the voice interactions and have the same (general) flow and API to interact with.

This leaves me doing some research on different technologies like api.ai, wit.ai, Lex, etc.

But, since this is an app for Alexa and I already rely on AWS and Amazon in general, I think I'd prefer to use Lex or just write a native Alexa app for now.

I'm having a hard time understanding the differences between the two. I understand that Alexa was built using Lex and I see that they have similar concepts like intent, slots, etc.

But, I'm looking for any differences between the two services:

1. Would using Lex allow me to more easily integrate with other devices? Or is there any benefit?

2. Would using Lex allow me greater flexibility in designing/modifying the flow of a conversation? It seems like Lex is a little more complex and, therefore, might allow greater functionality.

3. Or is it just that Lex offers nearly the exact same functionality and is just meant for devices that aren't Alexa?

4. Does Lex offer any more analytics processing than Alexa? In Alexa I can only see intents/slots, but if I could see the actual text in Lex, that would be ideal.

Answer 1

Alexa Skills Kit (ASK) is used to build skills for use in the Alexa ecosystem and devices and lets developers take advantage of all Alexa capabilities such as the Smart Home and Flash Briefing API, streaming audio and rich GUI experiences. Amazon Lex bots support both voice and text and can be deployed across mobile and messaging platforms.

Lex Faqs

Answer 2

In my view (very limited Alexa dev experience) AWS Lex allows greater control over the bot dialog. It defines separate validation and fulfilment code hooks, enables specific prompts for slots on the UI, supports programmatic transitions between intents, gives proper versioning and alias handling, etc... so it seems it's more of an enterprise offering as opposed to "consumer-level" Alexa skills.

But surprisingly it lacks a few important features, e.g. it does not have a built in "boolean" slot type, so you have to code around yes/no questions. Or there are no Cloudwatch logs for lex at all. Also the (growing) list of integrations will make it more generic.

But despite being a huge AWS fan, I have to say that api.ai seems to be a reasonably more polished, feature rich proposition at least for now.

With regards to integrations with other devices, I do not think any of these platforms promise that. It seems that if you target Google home, than it's their platform, if you target Alexa, then hmm it's alexa or api.ai (not sure if Google will push this in the future). But if you plan to integrate with chat platforms, or directly into web applications, then I think all major platforms can give you that, or in the near future.

By the way, have you checked IBM Watson or Microsoft Bot framework (with LUIS)? They are also very capable, complete frameworks, too, don't discount them!