A little Go library to easily handle Alexa custom skill requests, conforming to the official Alexa Skill Kit JSON reference. golexa handles all the heavy lifting, so you can concentrate on building great apps within minutes.

go get github.com/b00giZm/golexa

or, if you prefer Glide

glide get github.com/b00giZm/golexa

Your first Alexa app in less than 10 lines of code.

import "github.com/b00giZm/golexa"

app := golexa.Default()
app.OnLaunch(func(a *golexa.Alexa, req *golexa.Request, session *golexa.Session) *golexa.Response {
        return a.Response().AddPlainTextSpeech("Welcome to my awesome app")
})

response := app.Process(json)

You can attach several handlers to deal with the different Alexa request types:

app.OnLaunch(func(a *Alexa, req *Request, session *Session) *Response) { ... })

app.OnIntent(func(a *Alexa, intent *Intent, req *Request, session *Session) *Response) { ... })

app.OnSessionEnded(func(a *Alexa, req *Request, session *Session) *Response) { ... })

Every handler has a *golexa.Alexa pointer as first parameter, which gives you access to several convenience methods for quickly building response objects.

When building bigger apps, using the built-in callback handlers can be a bit cumbersome, especially if you have lots of different intents. For this special case, golexa provides several interfaces to implement for your own handlers:

type Handler interface{}

type LaunchHandler interface {
	Handler
	HandleLaunch(a *Alexa, req *Request, session *Session) *Response
}

type IntentHandler interface {
	Handler
	HandleIntent(a *Alexa, intent *Intent, req *Request, session *Session) *Response
}

type SessionEndedHandler interface {
	Handler
	HandleSessionEnded(a *Alexa, req *Request, session *Session) *Response
}

With these interfaces and the Init() method of golexa.Alexa, you can have one handler for each intent, which is a much cleaner solution than having a big handler with lots of if else statements:

myHandlers := []golexa.Handler{
        myFooIntentHandler,
        myBarIntentHandler,
        ...
}

app := golexa.Init(myHandlers)
response := app.Process(json)

Those handlers are processed in the order in which they were provided. The processing goes on until one of the handlers return a valid *golexa.Reponse. If a handler can't handle a specific request, it can just return nil and the next consecutive handler is called.

(by the way: You can of course provide your own handlers for LaunchRequest and SessionEndedRequest inside the Init() slice, but remember that there can be only one LaunchRequest handler and just one SessionEndedRequest handler, which means that if you provide several of them, all but the very last one will be discarded.)

The main motivation for this library was to have something which plays nicely with the awesome Apex toolchain and their Golang bridge for AWS Lambda:

package main

import (
        "github.com/apex/go-apex"
        "github.com/b00giZm/golexa"
)

func main() {
        apex.HandleFunc(func(event json.RawMessage, ctx *apex.Context) (interface{}, error) {
                app := golexa.Default()
                app.OnLaunch(func(a *golexa.Alexa, req *golexa.Request, session *golexa.Session) *golexa.Response {
                        return a.Response().AddPlainTextSpeech("Welcome to my awesome app")
                })
        
                return app.Process(event)
        })
}

Boom! Done 🎉

Prerequisites:

• Go >= 1.6.2
• Glide >= 0.10.2

Fork and clone this repository

cd $GOATH/src/github.com/b00giZm
git clone https://github.com/b00giZm/golexa.git

Install dependencies via Glide

glide install

Run tests

go test

Pascal Cremer

• Email: hello@codenugget.co
• Twitter: @b00gizm
• Web: http://codenugget.co

The MIT License (MIT)

Copyright (c) 2016 Pascal Cremer

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.