AWS - Sending SMS without subscription - amazon-web-services

Question

I am working on an app on AWS that needs to send text messages to customers. At times, the app just needs to send a single text message (AWS Transactional SMS may help here), at times it may need to text different groups of people (AWS doesn't seem to have a solution for this use case). It all depends on what the user is doing on the app.
I have explored the possibility of using SNS, but it requires users to be subscribed to a topic, which doesn't work for my use case. I have explored the possibility of using AWS Pinpoint, but it also doesn't seem to apply to my use case. I could use Twilio, but I would prefer to stay within AWS (Additionally, Twilio runs on AWS)
What is the best way to send text messages in the USA through AWS that doesn't require subscription to a topic?

Answer 1

If someone seeking for the answer of this Qn:
You can send SMS in 2 ways in AWS SNS.
Subscribe to a topic that is created in AWS SNS and send sms to all those numbers who had the subscription
Send SMS directly to a mobile number
What you need is the 2nd one.
I will demonstrate here how to do that with Ruby language.
Install the gem aws sns:
gem install aws-sdk-sns
require 'aws-sdk-sns'
1.Set SNS client
#sns_client = Aws::SNS::Client.new(
region: ENV['AWS_SNS_REGION'],
access_key_id: ENV['AWS_SNS_ACCESS_KEY'],
secret_access_key: ENV['AWS_SNS_SECRET_KEY']
)
2.Set SNS client attributes
#sns_client.set_sms_attributes({
attributes: {
'DefaultSenderID' => SENDER_ID,
'DefaultSMSType' => SMS_TYPE
}
})
3.Publish SMS
otp = (1000..9999).to_a.sample
#sns_client.publish({
phone_number: #mobile_no,
message: "#{OTM_MSG} #{otp}"
})
thats it!
OTM_MSG: ‘Your message comes here’
SMS_TYPE : ‘Transactional’ or ‘Promotional’
If you want to send OTP / bank transactions, then it is ‘Transactional’. Else if you want to send some promotional sms of your product then it is ‘Promotional’
SENDER_ID: is the sender id that you have already registered if you want to use your own sender id.
If you don't have sender id skip the step 2 - Set SNS client attributes
AWS_SNS_REGION, AWS_SNS_ACCESS_KEY, AWS_SNS_SECRET_KEY - are the credentials of your AWS account from where you would like to use SNS.
See the AWS documentation for this here:
https://docs.aws.amazon.com/sns/latest/dg/sms_publish-to-phone.html
It also provides code for Java language.
If you want to know more I have written an article here:
https://railsdrop.com/2021/03/04/aws-sns-how-to-send-sms/

Answer 2

Use the Publish action from the SNS service to send a text to a single phone without a topic. You could repeatedly call Publish to send texts to multiple phones.
https://docs.aws.amazon.com/sns/latest/dg/sms_publish-to-phone.html
Use the CreateTopic, Subscribe, and Publish actions from the SNS service to send a text to a multiple phones at once (uses a Topic).
https://docs.aws.amazon.com/sns/latest/dg/sms_publish-to-topic.html