This use case shows how to make use of Use Case - Running your Nimbus Flows From Anywhere to route incoming WhatsApp messages to Nimbus using Twilio.

Overview

We assume that you have a UI which can be used as a WhatsApp client to display WhatsApp messages from clients. It also offers a form to reply to messages. On this page, we describe the backend of this application.

We will create two Power Automate Flows to receive and send WhatsApp messages over Twilio and one for distributing the message as an external task to Nimbus.

Create Your Flows

Flow 1: Push messages from Twilio to your App

In Twilio, you can configure a URL to push messages to whenever a new message is received. You could directly route to the API of your custom app without passing through Power Automate. But sometimes this is not easy and depends on how much customization your app provides, if it is reachable from the outside, whether you've built it inhouse or if you need to use predefined ways to integrate custom APIs. We show you how to implement this step as a Power Automate Flow and use the Azure generated public URL in Twilio.

1. Start with a “When a HTTP request is received” trigger.
2. Add the JSON schema of the Twilio message to it.
   As we developed the solution the schema looked like this:

{
        "type": "object",
        "properties": {
            "$content-type": {
                "type": "string"
            },
            "$content": {
                "type": "string"
            },
            "$formdata": {
                "type": "array",
                "items": {
                    "type": "object",
                    "properties": {
                        "key": {
                            "type": "string"
                        },
                        "value": {
                            "type": "string"
                        }
                    },
                    "required": [
                        "key",
                        "value"
                    ]
                }
            }
        }
    }
    

3. Store the MessageID in a variable. Use "triggerFormDataValue('SmsMessageSid')" as input.
4. Add another HTTP request to the flow. You can now get the message content over the Twilio API using the API URL, your username, password, and the stored MessageID.
5. Notify your own application about the reception of the message for further handling (surface message content).
6. Save the flow.
7. Copy the trigger URL. In Twilio, forward all Inbound Messages to your Inbound Power Automate Flow using the URL.

Flow 2: Route the message through Nimbus

In your app, on getting a notification of a new message, you want to route the WhatsApp message to Nimbus via external tasks. Use the content of the message received from flow 1 and create an external task in Nimbus for it as described in Use Case - Running your Nimbus Flows From Anywhere.

You can configure a screen pop for your app by setting the Conversation Context of the service to the route that links to the message in your app.

Flow 3: Reply to a message

Again, as for flow 1, you could directly call Twilio's Rest APIs from within your custom app - we recommend this option. But if it is not possible, we show you a way how to use Power Automate for it.

In your app, you want to send a message back over Twilio via your reply form. It is possible to trigger a Power Automate flow and use Twilio's Power Automate Connector to send the message. The flow starts with the “When a HTTP request is received” secured trigger and uses the “Send Text Message (SMS)” element from the Twilio Connector. It is important to use this one and add the prefix “whatsapp:” to the To Phone Number and From Phone Number fields so that Twilio recognizes it as a WhatsApp message.

Test Your Flows

In your Nimbus service, you should see the incoming message. On the other end, ensure that you receive the replies.