Step 6: Enable Your Skill to Complete Account Linking

POST /v1/users/~current/skills/{skillId}/enablement HTTP/1.1
Host: api.amazonalexa.com
Content-Type: application/json
Authorization: "Bearer {Amazon access token}"
{
    "stage": "development or live",
    "accountLinkRequest": {
    "redirectUri": "https://yourRedirectURI",
    "authCode": "Your user's authorization code from your authorization server",
    "type": "AUTH_CODE"
    }
}

HTTP 201
Content-Type: application/json
{
  "skill": {
    "stage": "your skill stage",
    "id": "your skill id"
  },
  "user": {
    "id": "User ID"
  },
  "accountLink": {
    "status": "LINKED"
  },
  "status": "ENABLED"
}

const _ = require('lodash');
const axios = require('axios');
const {config} = require('../config/skillconfig');
const {getAccessTokenByAuthcode} = require('./oauthrequests');

// Request to the Alexa Skill Enablement API in the backend
const AlexaServiceRequest = (() => {
    const header = (amazonAccessToken) => {
        return {
            "headers": {
                "Content-Type": "application/json",
                "Authorization": "Bearer " + amazonAccessToken
            }
        };
    };

    const body = (userAuthCode) => {
        return {
            "stage": config.skillConfig.stage,
            "accountLinkRequest": {
                "redirectUri": config.skillConfig.redirect_uri,
                "authCode": userAuthCode,
                "type": "AUTH_CODE"
            }
        }
    }

    return {
        createEnablement: (amazonAccessToken, userAuthCode) => {
            return {
                header: header(amazonAccessToken),
                body: body(userAuthCode)
            }
        }
    }
})();

function createEnablementWithAccountLink(amazonAuthCode, userAuthcode, state) {

    // Exchange Amazon OAuth Code for Amazon Access Token
    const tokenPromise = getAccessTokenByAuthcode(amazonAuthCode, state);
    return tokenPromise.then((res) => {
        if (!_.has(res, 'data.access_token')) {
            throw Error("Amazon AccessToken is invalid");
        }
        console.log(res);
        const amazonAccessToken = res.data.access_token;

        // Call the Alexa Skill Enablement API to create enablement
        const createEnablementRequest = AlexaServiceRequest.createEnablement(amazonAccessToken, userAuthcode);
        return sendPostRequests(config.endpoints.alexaServiceEndpoints, createEnablementRequest.body, createEnablementRequest.header);
    });
}

// Post enablement to the Alexa Skill Enablement API
function sendPostRequests(endpoints, body, header) {
    var alexaServicePromises = []

    // Post for each Alexa Skill Enablement API regional endpoint for the user
    endpoints.forEach((endpoint)=> {
        alexaServicePromises.push(axios.post(endpoint, body, header));
    });
    return new Promise((resolve, reject)=> {
        var failures = 0;
        alexaServicePromises.forEach((promise)=> {
            promise.then((res)=> {
                if (res.status == 201) {
                    resolve(res.data);
                } else {
                    if (++failures == alexaServicePromises.length) {
                        reject(res.data);
                    }
                }
            }).catch((err)=> {
                if (++failures == alexaServicePromises.length) {
                    reject(err.data);
                }
            })
        })
    });
}