Alexa + AWS Lambda Hello World in Python

I recently began to fool around with integrating Amazon Alexa with my Home Assistant install in a custom manner. By default, you can set up an emulated Hue in the HA configuration which allows you to toggle lights, but I wanted to do more – which means I had to build my own custom Alexa skills.

It’s amazing to me, that after hours and hours of research, I was unable to find a single solid “Hello World” tutorial online. Sure, there are plenty of tutorials, but they’re all fairly complex, or contain loads of code or information that I didn’t need. When developing in unfamiliar territory, I usually like to start with a simple “Hello World”. Below is an AWS Lambda function that you can use to echo “Hello World” through your Alexa or Echo Dot.

from __future__ import print_function

def build_response_payload( title, output, reprompt_text, should_end_session ):
	return {
		'outputSpeech': {
			'type': 'PlainText',
			'text': output
		},
		'card': {
			'type': 'Simple',
			'title': "alexaHelloWorld - " + title,
			'content': "alexaHelloWorld - " + output
		},
		'reprompt': {
			'outputSpeech': {
				'type': 'PlainText',
				'text': reprompt_text
			}
		},
		'shouldEndSession': should_end_session
	}

def build_response( session_attributes, speechlet_response ):
	return {
		'version': '1.0',
		'sessionAttributes': session_attributes,
		'response': speechlet_response
	}

def say_hello_world():
	session_attributes = {}
	card_title = "Hello World"
	speech_output = "Hello World"
	should_end_session = True
	return build_response( session_attributes, build_response_payload( card_title, speech_output, speech_output, should_end_session ) )

def lambda_handler( event, context ):
	return say_hello_world()

Here are a few pointers to get you started on your journey:
– Paste this into the inline editor in new AWS Lambda function
– Select “Python 2.7” and set the handler to lambda_function.lambda_handler
– Create a custom role and use the default options
– Set up the Lambda function and the Alexa skill pretty much how every other tutorial on the web tells you to
– The “Test” button in AWS Lambda will report errors. You should instead test directly from Alexa Skills in the AWS Developer Console. This is a little bit unintuitive and I’m not sure why it is this way. But test attempts from Lambda DO fail every time for me. I’ll update if I figure out why.

Since I typically prefer JS over Python, I’m going to do up another Hello World tutorial in Lambda Node.js shortly, this is just what I happened to get working first. I hope you can make some use of it. Enjoy!

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