How to get an Alexa userId?

Question

I'm building an Alexa Skill, and it requires that I store the userId of a user. I've tried to retrieve it with event.session.user.userId. However, when I call console.log(event.session.user.userId) the output is literally amzn1.ask.account.[unique-value-here]. I've looked at several similar questions, and none of them provide a clear enough answer for me.

I'm not sure if this is a bug, a developer-only thing, or if the userId is simply anonymized. If so, is there a way to get the actual userId? I imagine there would be, since Amazon has written an entire guide on it here:

https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/linking-an-alexa-user-with-a-user-in-your-system.

However, after a long day of debugging, I'm not sure what's real and what's not anymore.

var request = require('request');
var firebase = require('firebase');
var config = {
    apiKey: "my-api-key",
    authDomain: "stuff...",
    databaseURL: "more stuff...",
    storageBucket: "even more stuff...",
};
firebase.initializeApp(config);
// Get a reference to the database
var database = firebase.database();

exports.handler = (event, context) => {
    try {
        // New session
        if (event.session.new) {
            // New Session
            console.log("NEW SESSION");
        }

        // Launch Request
        switch (event.request.type) {
            case "LaunchRequest":
                var url = "https://api.random.org/json-rpc/1/invoke";
                var myRequest = {
                    "jsonrpc": "2.0",
                    "method": "generateStrings",
                    "params": {
                        "apiKey": "another-api-key",
                        "n": "1",
                        "length": "3",
                        "characters": "abcdefghijklmnopqrstuvwxyz0123456789"
                    },
                    "id": 24
                }
                var pin;
                request.post(
                    url,
                    {json: myRequest},
                    function (error, response, body) {
                        if (!error && response.statusCode == 200) {
                            console.log(event.session.user.userId); // **Here**, output is literally amzn1.ask.account.[unique-value-here] 
                            pin = body.result.random.data[0];
                            writeUserPin(pin);
                            var welcome = "Welcome";
                            var pinStatement = "Your 3 letter or number pin is: " + processPinForSpeech(pin);
                            context.succeed(
                                generateResponse(
                                    buildSpeechletReponse(welcome + pinStatement, true),
                                    {}
                                )
                            );
                            console.log(pin);
                        }
                        else {
                            console.log(error);
                        }
                    }
                );
                console.log("LAUNCH REQUEST");
                break;
            // Intent Request
            case "IntentRequest":
                console.log("INTENT REQUEST");
                break;

            // Session Ended Request
            case "SessionEndedRequest":
                console.log("SESSION ENDED REQUEST");
                break;

            default:
                context.fail(`INVALID REQUEST TYPE: ${event.request.type}`);
        }
    }
    catch (error) {
        context.fail(`Exception: ${error}`);
    }

}
    // Helpers
buildSpeechletReponse = (outputText, shouldEndSession) => {
    return {
        outputSpeech : {
            type: "PlainText",
            text: outputText
        },
        shouldEndSession: shouldEndSession
    };
}

generateResponse = (speechletResponse, sessionAttributes) => {
    return {
        version: "1.0",
        sessionAttributes: sessionAttributes,
        response: speechletResponse
    };
}

function writeUserPin(pin) {
    console.log("writing stuff");
    firebase.database().ref('newPins/' + pin).set({
        num : ""
    });
}

function processPinForSpeech(pin) {
    var wordNumArr = ["zero", "one", "two", "three", "four",
     "five", "six", "seven", "eight", "nine"];
    processedPin = "";
    for (i = 0; i < pin.length; i++){
        var currentChar = pin.charAt(i);
        if (isNaN(Number(currentChar))){
            processedPin += currentChar + ". ";
        }
        else {
            processedPin += wordNumArr[Number(currentChar)] + ". ";
        }
    }
    return processedPin
}

The following is the output on the CloudWatch logs:


16:16:19
START RequestId: 48e335c5-d819-11e6-bc01-a939911adc24 Version: $LATEST

16:16:19
2017-01-11T16:16:19.639Z    48e335c5-d819-11e6-bc01-a939911adc24    NEW SESSION

16:16:19
2017-01-11T16:16:19.758Z    48e335c5-d819-11e6-bc01-a939911adc24    LAUNCH REQUEST

16:16:20
2017-01-11T16:16:20.457Z    48e335c5-d819-11e6-bc01-a939911adc24    amzn1.ask.account.[unique-value-here]

16:16:20
2017-01-11T16:16:20.457Z    48e335c5-d819-11e6-bc01-a939911adc24    writing stuff

16:16:20
2017-01-11T16:16:20.520Z    48e335c5-d819-11e6-bc01-a939911adc24    dd2

16:16:20
END RequestId: 48e335c5-d819-11e6-bc01-a939911adc24

16:16:20
REPORT RequestId: 48e335c5-d819-11e6-bc01-a939911adc24  Duration: 1005.48 ms    Billed Duration: 1100 ms Memory Size: 128 MB    Max Memory Used: 38 MB

Answer 1

You are doing it right. This amzn1.ask.account.[unique-value-here] is in-fact the full userId. You can observe this for yourself by enabling your skill from an Echo, logging several requests to your alexa skill, and observing that the userId between these requests is the same value.

Per the JSON Reference:

userId: A string that represents a unique identifier for the user who made the request. The length of this identifier can vary, but is never more than 255 characters. The userId is automatically generated when a user enables the skill in the Alexa app.

Note: Disabling and re-enabling a skill generates a new identifier.

If you only need to persist user attributes between sessions, this value will be sufficient and you can use it to uniquely identify this user so long as they have the skill enabled.

If you need to link an account, the value you're looking for is accessToken and lives in that same user object following successful account link. Per the same JSON Reference as above:

accessToken: a token identifying the user in another system. This is only provided if the user has successfully linked their account. See Linking an Alexa User with a User in Your System for more details.