WhatsApp is a popular messaging app that is used by millions of people around the world. In some cases, it may be useful to automate the process of sending messages through WhatsApp, for example, to send reminders or notifications to a large group of people.

One way to automate WhatsApp messaging is by using the Go programming language. Go is a popular language for building web applications and microservices, and it has a number of libraries and tools that make it easy to work with the WhatsApp API provided by Twilio.

In this article, we will look at how to automate WhatsApp messaging using Go and the Twilio WhatsApp API. We will also explore how to host Go functions on different cloud platforms, including Azure, AWS, and GCP.

Before we begin, you will need to sign up for a Twilio account and purchase a WhatsApp messaging sandbox. You can find more information about how to do this on the Twilio website.

First, install the required packages:

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go get github.com/twilio/twilio-go

Next, import the necessary packages in your Go program:

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import (
    "fmt"
    "github.com/twilio/twilio-go"
)

Next, define your Twilio account SID, auth token, and the WhatsApp sandbox phone number:

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accountSID := "YOUR_ACCOUNT_SID"
authToken := "YOUR_AUTH_TOKEN"
fromNumber := "YOUR_WHATSAPP_SANDBOX_NUMBER"

to := "whatsapp:+1234567890"
body := "Hello, world!"

client := twilio.NewClient(accountSID, authToken, nil)

message, resp, err := client.Messages.SendMessage(fromNumber, to, body, nil)
if err != nil {
    fmt.Println(err)
    return
}

fmt.Println(message.Sid)

This code creates a new Twilio client using your account SID and auth token, and then calls the SendMessage function to send a message to the specified phone number. If the message was sent successfully, the message SID will be printed to the console.

You can also include media in your WhatsApp message by specifying a URL in the mediaURL parameter of the SendMessage function. For example:

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to := "whatsapp:+1234567890"
body := "Check out this image!"
mediaURL := "https://example.com/image.jpg"

client := twilio.NewClient(accountSID, authToken, nil)

message, resp, err := client.Messages.SendMessage(fromNumber, to, body, &mediaURL)
if err != nil {
    fmt.Println(err)
    return
}

fmt.Println(message.Sid)

This code will send a message with the specified body and media URL to the specified phone number. If the message was sent successfully, the message SID will be printed to the console.

Now that we’ve seen how to use Go and the Twilio WhatsApp API to send messages through WhatsApp, let’s take a look at how to host Go functions on different cloud platforms.

Hosting as Serverless offering on Azure , AWS and GCP

One option is to use Azure Functions to host your Go functions. To do this, you will need to install the Azure Functions extension for Go, create a new Azure Functions project, and then add your Go code to the project. You can find more information about how to do this in the Azure Functions documentation.

Another option is to use AWS Lambda to host your Go functions. To do this, you will need to create a new Lambda function and then use the aws-lambda-go package to create a Go function that can be invoked by Lambda. You can find more information about how to do this in the AWS Lambda documentation.

Finally, you can also use Google Cloud Functions to host your Go functions. To do this, you will need to create a new Cloud Functions project, install the cloud-functions-go package, and then write your Go code using the Cloud Functions API. You can find more information about how to do this in the Google Cloud Functions documentation.

I hope this article has been helpful in showing you the power of WhatsApp automation using Go and the various options for hosting Go functions on different cloud platforms. Let me know if you have any questions or need further assistance.

Example Hosting : Azure Function

Here is an example of how you can use Azure Functions to host a Go function that sends a message through WhatsApp using the Twilio API:

1. Install the Azure Functions extension for Go:

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go get github.com/Azure/azure-functions-go-worker

2. Create a new Azure Functions project and add a new function:

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func init

3. Import the required packages in your Go code:

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import (
    "context"
    "fmt"
    "github.com/twilio/twilio-go"
    "github.com/Azure/azure-functions-go-worker/bindings"
)

4. Define your Twilio account SID, auth token, and the WhatsApp sandbox phone number:

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accountSID := "YOUR_ACCOUNT_SID"
authToken := "YOUR_AUTH_TOKEN"
fromNumber := "YOUR_WHATSAPP_SANDBOX_NUMBER"

5. Create a new Azure Functions function that takes an HTTP trigger and sends a message through WhatsApp:

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func SendWhatsAppMessage(ctx context.Context, req *bindings.HTTPRequest) (bindings.HTTPResponse, error) {
    to := "whatsapp:+1234567890"
    body := "Hello, world!"

    client := twilio.NewClient(accountSID, authToken, nil)

message, resp, err := client.Messages.SendMessage(fromNumber, to, body, nil)
if err != nil {
    fmt.Println(err)
    return bindings.HTTPResponse{
        StatusCode: 500,
        Body:       err.Error(),
    }, err
}

return bindings.HTTPResponse{
    StatusCode: 200,
    Body:       message.Sid,
}, nil

This function creates a new Twilio client using your account SID and auth token, and then calls the SendMessage function to send a message to the specified phone number. If the message was sent successfully, the message SID will be returned in the HTTP response. If an error occurred, the error will be returned in the response.

To deploy this function to Azure Functions, you will need to build and package the function and then use the Azure Functions CLI to create a new function app and deploy the package. You can find more information about how to do this in the Azure Functions documentation.

I hope this example has been helpful in showing you how to use Azure Functions, you can do it similarly on AWS and GCP.