How to create a WhatsApp custom channel with Amazon Pinpoint

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How to add WhatsApp as an Amazon Pinpoint Custom Channel

WhatsApp now reports over 2 billion users in 180 countries, making it a prime place for businesses to communicate with their customers. In addition to native channels like SMS, push notifications, and email, Amazon Pinpoint’s custom channels enable you to extend the capabilities of Amazon Pinpoint and send messages to customers through any API-enabled service, like WhatsApp. With these new channels, you have full control over the message delivery to the endpoints associated with each custom channel campaign.

In this post, we provide a quick overview of the features and capabilities of using a custom channel as part of campaigns. We also provide a blueprint that you can use to build your first sandbox integration with WhatsApp as a custom channel.

Note: WhatsApp is a third-party service subject to additional terms and charges. Amazon Web Services isn’t responsible for any third-party service that you use to send messages with custom channels.

How to add WhatsApp as a custom channel:

Prerequisites

Before creating your new custom channel, you must have the integration ready and an Amazon Identity and Account Management (IAM) User created with the necessary permissions. First set up the following:

Create an IAM administrator. For more information, see Creating your first IAM admin user and group in the IAM User Guide. Specify the credentials of this IAM User when you set up the AWS Command Line Interface (CLI).
Configure the AWS CLI. For more information about setting up the AWS CLI, see Configuring the AWS CLI.
Follow the steps at Meta documentation – https://developers.facebook.com/docs/whatsapp/cloud-api/get-started to register as a Meta Developer and getting started with WhatsApp Business Cloud API provided directly by Meta. By completing step 1 and step 2 of the above documentation, you should be able to
1. Register as a Meta Developer,
2. Claim a test phone for sending messages on WhatsApp,
3. Verify a recipient phone number (since, currently you’re in Sandbox, you can send WhatsApp messages only to the verified phone numbers. You can verify upto 5 phone numbers)
4. and finally send a test message on Whatsapp using a provided sample POST request. Remember to review the terms of use for WhatsApp.
In the test message sent above, you have used temporary Access Token credentials which expires in 23 hours. In order to get permanent Access Token, generate a ‘System User Access Token’ by following the steps mention here – https://developers.facebook.com/docs/whatsapp/business-management-api/get-started/

Screenshot of WhatsApp test message sent from Meta Console.

Procedure:

Step 1: Create an Amazon Pinpoint project.

In this section, you create and configure a project in Amazon Pinpoint. Later, you use this data to create segments and campaigns.

To set up the Amazon Pinpoint project

Sign in to the Amazon Pinpoint console at http://console.aws.amazon.com/pinpoint/.
On the All projects page, choose Create a project. Enter a name for the project, and then choose Create.
On the Configure features page, under SMS and Voice, choose Configure.
Under General settings, select Enable the SMS channel for this project, and then choose Save changes.
In the navigation pane, under Settings, choose General settings. In the Project details section, copy the value under Project ID. You need this value for later.

Step 2: Create an endpoint.

In Amazon Pinpoint, an endpoint represents a specific method of contacting a customer. This could be their email address (for email messages) or their phone number (for SMS messages) or a custom endpoint type. Endpoints can also contain custom attributes, and you can associate multiple endpoints with a single user. In this step, we create an SMS endpoint that is used to send a WhatsApp message.

To create an endpoint using AWS CLI, at the command line, enter the following command:

aws pinpoint update-endpoint –application-id <project-id> \
–endpoint-id 12456 –endpoint-request “Address='<mobile-number>’, \
ChannelType=’SMS’,Attributes={username=[‘testUser’],integrations=[‘WhatsApp’]}”

In the preceding example, replace <project-id> with the Amazon Pinpoint Project ID that you copied in step 1.

Replace <mobile-number> with your phone number with country code (for example, 12065550142). For the WhatsApp integration to work, you must use the mobile number that are registered on WhatsApp and are already verified on Meta Developer Portal (since your Meta account is currently in sandbox).

Note: WhatsApp Business Cloud message API doesn’t require ‘+’ symbol in the front of the Phone number. So in case you plan to use this segment for both SMS and Custom Channel, you may configure Phone Number in E.164 format (for example, +12065550142) and remove ‘+’ symbol in the Lambda function code that we create in the step 4.

Step 3: Storing WHATSAPP_AUTH_TOKEN, and WHATSAPP_FROM_NUMBER_ID in AWS Secrets Manager.

We can securely store the WhatsApp Auth Token and WhatsApp From Number Id which we have received in the previous steps in AWS Secrets Manager.

Open the AWS Secrets Manager console at https://us-east-1.console.aws.amazon.com/secretsmanager/listsecrets?region=us-east-1 (in the required AWS region), and then click on “Store a new Secret”.
Under “Secret Type”, choose Other type of secret.
Under Key/value Pair, add the following Key-Value pairs:
1. WHATSAPP_AUTH_TOKEN: <Pass the Auth Token generated previously>
2. WHATSAPP_FROM_NUMBER_ID : <Pass the From Number Id>.
Click Next
Provide the Secret name “MetaWhatsappCreds” and provide a suitable description.
Click Next twice and finally click “Store” button.

Step 4: Create an AWS Lambda.

You must create an AWS Lambda that has the code that calls Meta WhatsApp Business Cloud API and sends a message to the endpoint.

Open the AWS Lambda console at http://console.aws.amazon.com/AWSLambda, and then click on Create Function.
Choose Author from scratch.
For Function Name, enter ‘WhatsAppTest’.
For Runtime, select Python 3.9.
Click Create Function.
For the function code, copy the following and paste into the code editor in your AWS Lambda function:

import base64
import json
import os
import urllib
from urllib import request, parse
import boto3
from botocore.exceptions import ClientError

WhatsApp_messageAPI_URL = "https://graph.facebook.com/v15.0/" 

def get_secret():

    secret_name = "MetaWhatsappCreds"
    region_name = "us-east-1"
    # Pass the required AWS Region in which Secret is stored

    # Create a Secrets Manager client
    session = boto3.session.Session()
    client = session.client(
        service_name='secretsmanager',
        region_name=region_name
    )

    try:
        get_secret_value_response = client.get_secret_value(
            SecretId=secret_name
        )
    except ClientError as e:
        # For a list of exceptions thrown, see
        # https://docs.aws.amazon.com/secretsmanager/latest/apireference/API_GetSecretValue.html
        raise e

    # Decrypts secret using the associated KMS key.
    secret = get_secret_value_response['SecretString']
    return secret
   
def lambda_handler(event, context):
    credentials = get_secret()
    WhatsApp_AUTH_TOKEN = json.loads(credentials)["WHATSAPP_AUTH_TOKEN"]
    WhatsApp_FROM_NUMBER_ID = json.loads(credentials)["WHATSAPP_FROM_NUMBER_ID"]
    if not WhatsApp_AUTH_TOKEN:
        return "Unable to access WhatsApp Auth Token."
    elif not WhatsApp_FROM_NUMBER_ID:
        return "Unable to access WhatsApp From Number Id."
    # Lets print out the event for our logs 
    print("Received event: {}".format(event))

    populated_url = WhatsApp_messageAPI_URL + WhatsApp_FROM_NUMBER_ID + "/messages"

    for key in event['Endpoints'].keys(): 
        to_number = event['Endpoints'][key]['Address']
        # Example body and using an attribute from the endpoint
        username = event['Endpoints'][key]['Attributes']['username'][0]
        body = "Hello {}, here is your weekly 10% discount coupon: SAVE10".format(username)
        post_params = {"messaging_product":"whatsapp","to": to_number ,"recipient_type": "individual","type": "text", "text":{"preview_url": "false","body": body}}
        # encode the parameters for Python's urllib 
        print(post_params)
        data = parse.urlencode(post_params).encode('ascii') 
        req = request.Request(populated_url)
        req.add_header("Authorization", WhatsApp_AUTH_TOKEN ) 
        req.add_header("Content-Type","application/json")
        try:
            # perform HTTP POST request
            with request.urlopen(req, data) as f:
                print("WhatsApp returned {}".format(str(f.read().decode('utf-8')))) 
        except Exception as e:
            # something went wrong!
            print(e)

    return "WhatsApp messages sent successfully"

Add permissions to your AWS Lambda to allow Amazon Pinpoint to invoke it using AWS CLI:

aws lambda add-permission \
–function-name WhatsAppTest \
–statement-id sid \
–action lambda:InvokeFunction \
–principal pinpoint.us-east-1.amazonaws.com \
–source-arn arn:aws:mobiletargeting:us-east-1:<account-id>:apps/<Pinpoint ProjectID>/*

Step 5: Create a segment and campaign in Amazon Pinpoint.

Now that we have an endpoint, we must add it to a segment so that we can use it within a campaign. By sending a campaign, we can verify that our Amazon Pinpoint project is configured correctly, and that we created the endpoint correctly.

To create the segment and campaign:

1. Open the Amazon Pinpoint console at http://console.aws.amazon.com/pinpoint, and then choose the project that you created in step 1.
2. In the navigation pane, choose Segments, and then choose Create a segment.
3. Name the segment “WhatsAppTest.” Under Segment group 1, include all audiences in the Base Segment and add the following Criteria:
4. For Choose an endpoint attribute, choose integrations, then for values, choose WhatsApp.
5. Confirm that the Segment estimate section shows that there is one eligible endpoint, and then choose Create segment.
6. In the navigation pane, choose Campaigns, and then choose Create a campaign.
7. Name the campaign “WhatsAppTest.” Under Choose a channel for this campaign, choose Custom, and then choose Next.
8. On the Choose a segment page, choose the “WhatsAppTest” segment that you just created, and then choose Next.
9. In Create your message, choose the AWS Lambda function we just created, ‘WhatsAppTest.’ Select SMS in the Endpoint Options. On the Choose when to send the campaign page, keep all of the default values, and then choose Next. On the Review and launch page, choose Launch campaign.

Screenshot of Pinpoint console showing creation of message for Custom Channel.

Within a few seconds, you should receive a WhatsApp message at the phone number that you specified when you created the endpoint and verified on the Meta Developer portal.

Your Custom channel solution for WhatsApp is now ready to use. But first, review and upgrade your WhatsApp sandbox. This post is simply a walkthrough to show you how quickly you can prototype and start sending WhatsApp messages with Pinpoint and Meta. However, for production usage, you need to make sure to review all of the additional terms and charges. Start here to understand more: https://developers.facebook.com/docs/whatsapp/cloud-api/get-started

As a next steps, you can go ahead and claim a Phone number for sending WhatsApp messages in production. You can further configure a Webhook which can help you in receiving WhatsApp message delivery status and other WhatsApp supported events.

There are several ways you can make this solution your own.

Customize your messaging: This post used an example message to be sent to your endpoints within the AWS Lambda. You can customize that message to fit your needs. See the various ways in which you can send WhatsApp messages here.
Expand endpoints in your application: This post only used one endpoint for the integration. You can use your WhatsApp integration with new endpoints by importing a segment that can be used with a new campaign. Learn how to import a segment here: https://docs.aws.amazon.com/pinpoint/latest/userguide/segments-importing.html
Use new integrations: This post focused on integrating your custom channel with WhatsApp but there are many other integrations that are possible when using AWS Lambda.

Amazon Pinpoint is a flexible and scalable outbound and inbound marketing communications service. Learn more here: https://aws.amazon.com/pinpoint/

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