Voice-Forward Account Linking Implementation Details

const LinkMyAccountRequestHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'IntentRequest'
      && request.intent.name === 'LinkMyAccount';
  },
  handle(handlerInput) {
    var accessToken = handlerInput.requestEnvelope.context.System.user.accessToken;
    if (accessToken == undefined){
       //Account is not linked
        return handlerInput.responseBuilder
        .speak(<value_prompt>)
        .addDirective({
            'type': 'Connections.StartConnection',
            'uri': 'connection://AMAZON.AskForAccountLinking/1',
            'onCompletion': 'RESUME_SESSION',
            'input': {
            '@version': '1',
            '@type': 'AskForAccountLinking'
            },
            'token': 'accountLinking'
            // Token can be anything that can be used to identify the request on session resumption
        })
            .getResponse();
    }else{
      // Handle the account already linked flow.
    }
  }
};

{
    "type": "Task.CompleteTask",
    "status": {
        "code": "string",
        "message": "string"
     }
    "token": "string"
    "result": {
      "status" : <account_linking_status_enum>
    }
}

const AccountLinkingSessionResumedHandler = {
    canHandle(handlerInput) {
        const request = handlerInput.requestEnvelope.request;
    return request.type === 'SessionResumedRequest' && request.cause.token === 'accountLinking'; // Token needs to be same as passed in request
    },
    handle(handlerInput) {
       const status = handlerInput.requestEnvelope.request.cause.status;
       const code = status.code;
       const message = status.message;
       console.log(`AccountLinkingSessionResumedHandler received status code : ${code} and message : ${message}`);

       const accountLinkingStatus = handlerInput.requestEnvelope.request.cause.result.status;

       if (code !== '200'){
        //Error occured in the request
        //Response
        return handlerInput.responseBuilder
            .speak(speechText)
            .withLinkAccountCard()
            .getResponse();
       }

       // Now check to see if the user passed or failed account linking.
        const accountLinkingTaskResult = handlerInput.requestEnvelope.request.cause.result;
        const accountLinkingTaskStatus = accountLinkingTaskResult.status;        
        if (accountLinkingTaskStatus === 'LINKED') {
         // Account was linked or is linked successfully as part of the request
         // <HANDLE_LINKED>
         //Response
        var accessToken = handlerInput.requestEnvelope.context.System.user.accessToken;

        // Logic to look up or create account if necessary
        // If you have a resource server that makes call internally to LWA to get the LWA ID
        // makeHttpCall('resource_server',accessToken);

        // If you need LWA_ID for your operation
        // https://developer.amazon.com/docs/login-with-amazon/obtain-customer-profile.html#call-profile-endpoint
        // makeHttpCall('https://api.amazon.com/user/profile?access_token=*',accessToken);
        // Use LWA_ID from the request above to look up or create an account as necessary

        // If you need customer contact information, use the Alexa Customer Profile API
        // https://developer.amazon.com/en-US/docs/alexa/custom-skills/request-customer-contact-information-for-use-in-your-skill.html

        return handlerInput.responseBuilder
            .speak(speechText)
            .getResponse();

        } else if (accountLinkingTaskStatus === 'DENIED') {
        // User denied the account linking permissions on request or sharing the information with the skill, hence the account linking flow failed.

        // <HANDLE_DENIED>
        //Response
        return handlerInput.responseBuilder
            .speak(speechText)
            .withLinkAccountCard()
            .getResponse();

        } else if (accountLinkingTaskStatus === 'NOT_ANSWERED') {
          // The user did not answer the question, asked as part of the skill.
          // <HANDLE_NOT_ANSWERED>
          //Response
        return handlerInput.responseBuilder
            .speak(speechText)
            .withLinkAccountCard()
            .getResponse();
        } else if (accountLinkingTaskStatus === 'USER_REQUIREMENTS_NOT_MET'){
          // The request was cancelled because the voice account linking flow can't be triggered for the customer or can't be completed.
          // <HANDLE_USER_REQUIREMENTS_NOT_MET>
          //Response
        return handlerInput.responseBuilder
            .speak(speechText)
            .withLinkAccountCard()
            .getResponse();
        }

    }
};