

End of support notice: On May 20, 2026, AWS will end support for AWS IoT Events. After May 20, 2026, you will no longer be able to access the AWS IoT Events console or AWS IoT Events resources. For more information, see [AWS IoT Events end of support](https://docs.aws.amazon.com/iotevents/latest/developerguide/iotevents-end-of-support.html).

# Creating a Lambda function in AWS IoT Events
<a name="alarms-create-lambda"></a>

AWS IoT Events provides a Lambda function that enables alarms to send and receive email and SMS notifications.

## Requirements
<a name="alarms-lambda-requirements"></a>

The following requirements apply when you create a Lambda function for alarms:
+ If your alarm sends SMS notifications, ensure Amazon SNS is configured to deliver SMS messages.
  + For more information, see the following documentation:
    + [Mobile text messaging with Amazon SNS](https://docs.aws.amazon.com/sns/latest/dg/sns-mobile-phone-number-as-subscriber.html) and [Origination identities for Amazon SNS SMS messages](https://docs.aws.amazon.com/sns/latest/dg/channels-sms-originating-identities.html) in the *Amazon Simple Notification Service Developer Guide*.
    + [What is AWS End User Messaging SMS?](https://docs.aws.amazon.com/sms-voice/latest/userguide/what-is-sms-mms.html) in the *AWS SMS User Guide*.
+ If your alarm sends email or SMS notifications, you must have an IAM role that allows AWS Lambda to work with Amazon SES and Amazon SNS.

  

  Example policy:

------
#### [ JSON ]

****  

  ```
  {
      "Version":"2012-10-17",		 	 	 
      "Statement": [
          {
              "Effect": "Allow",
              "Action": [
                  "ses:GetIdentityVerificationAttributes",
                  "ses:SendEmail",
                  "ses:VerifyEmailIdentity"
              ],
              "Resource": "*"
          },
          {
              "Effect": "Allow",
              "Action": [
                  "sns:Publish",
                  "sns:OptInPhoneNumber",
                  "sns:CheckIfPhoneNumberIsOptedOut",
                  "sms-voice:DescribeOptedOutNumbers"
              ],
              "Resource": "*"
          },
          {
              "Effect": "Deny",
              "Action": "sns:Publish",
              "Resource": "arn:aws:sns:*:*:*"
          },
          {
            "Effect" : "Allow",
            "Action" : [
              "logs:CreateLogGroup",
              "logs:CreateLogStream",
              "logs:PutLogEvents"
            ],
            "Resource" : "*"
          }
      ]
  }
  ```

------
+ You must choose the same AWS Region for both AWS IoT Events and AWS Lambda. For the list of supported Regions, see [AWS IoT Events endpoints and quotas](https://docs.aws.amazon.com/general/latest/gr/iot-events.html) and [AWS Lambda endpoints and quotas](https://docs.aws.amazon.com/general/latest/gr/lambda-service.html) in the *Amazon Web Services General Reference*.

For more information, see [What is AWS Lambda?](https://docs.aws.amazon.com/lambda/latest/dg/welcome.html) in the *AWS Lambda Developer Guide*.

## CloudFormation template
<a name="cfn-template"></a>

Use the following CloudFormation template to create your Lambda function.

```
AWSTemplateFormatVersion: '2010-09-09'
Description: 'Notification Lambda for Alarm Model'
Resources:
  NotificationLambdaRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: sts:AssumeRole
      Path: "/"
      ManagedPolicyArns:
        - 'arn:aws:iam::aws:policy/AWSLambdaExecute'
      Policies:
        - PolicyName: "NotificationLambda"
          PolicyDocument:
            Version: "2012-10-17"		 	 	 
            Statement:
              - Effect: "Allow"
                Action:
                  - "ses:GetIdentityVerificationAttributes"
                  - "ses:SendEmail"
                  - "ses:VerifyEmailIdentity"
                Resource: "*"
              - Effect: "Allow"
                Action:
                  - "sns:Publish"
                  - "sns:OptInPhoneNumber"
                  - "sns:CheckIfPhoneNumberIsOptedOut"
                  - "sms-voice:DescribeOptedOutNumbers"
                Resource: "*"
              - Effect: "Deny"
                Action:
                  - "sns:Publish"
                Resource: "arn:aws:sns:*:*:*"
  NotificationLambdaFunction:              
    Type: AWS::Lambda::Function
    Properties:
      Role: !GetAtt NotificationLambdaRole.Arn
      Runtime: python3.7
      Handler: index.lambda_handler
      Timeout: 300
      MemorySize: 3008
      Code:
        ZipFile: |
          import boto3
          import json
          import logging
          import datetime
          logger = logging.getLogger()
          logger.setLevel(logging.INFO)
          ses = boto3.client('ses')
          sns = boto3.client('sns')
          def check_value(target):
            if target:
              return True
            return False

          # Check whether email is verified. Only verified emails are allowed to send emails to or from.
          def check_email(email):
            if not check_value(email):
              return False
            result = ses.get_identity_verification_attributes(Identities=[email])
            attr = result['VerificationAttributes']
            if (email not in attr or attr[email]['VerificationStatus'] != 'Success'):
                logging.info('Verification email for {} sent. You must have all the emails verified before sending email.'.format(email))
                ses.verify_email_identity(EmailAddress=email)
                return False
            return True

          # Check whether the phone holder has opted out of receiving SMS messages from your account
          def check_phone_number(phone_number):
            try:
              result = sns.check_if_phone_number_is_opted_out(phoneNumber=phone_number)
              if (result['isOptedOut']):
                  logger.info('phoneNumber {} is not opt in of receiving SMS messages. Phone number must be opt in first.'.format(phone_number))
                  return False
              return True
            except Exception as e:
              logging.error('Your phone number {} must be in E.164 format in SSO. Exception thrown: {}'.format(phone_number, e))
              return False

          def check_emails(emails):
            result = True
            for email in emails:
                if not check_email(email):
                    result = False
            return result

          def lambda_handler(event, context):
            logging.info('Received event: ' + json.dumps(event))
            nep = json.loads(event.get('notificationEventPayload'))
            alarm_state = nep['alarmState']
            default_msg = 'Alarm ' + alarm_state['stateName'] + '\n'
            timestamp = datetime.datetime.utcfromtimestamp(float(nep['stateUpdateTime'])/1000).strftime('%Y-%m-%d %H:%M:%S')
            alarm_msg = "{} {} {} at {} UTC ".format(nep['alarmModelName'], nep.get('keyValue', 'Singleton'), alarm_state['stateName'], timestamp)
            default_msg += 'Sev: ' + str(nep['severity']) + '\n'
            if (alarm_state['ruleEvaluation']):
              property = alarm_state['ruleEvaluation']['simpleRule']['inputProperty']
              default_msg += 'Current Value: ' + str(property) + '\n'
              operator = alarm_state['ruleEvaluation']['simpleRule']['operator']
              threshold = alarm_state['ruleEvaluation']['simpleRule']['threshold']
              alarm_msg += '({} {} {})'.format(str(property), operator, str(threshold))
            default_msg += alarm_msg + '\n'

            emails = event.get('emailConfigurations', [])
            logger.info('Start Sending Emails')
            for email in emails:
              from_adr = email.get('from')
              to_adrs = email.get('to', [])
              cc_adrs = email.get('cc', [])
              bcc_adrs = email.get('bcc', [])
              msg = default_msg + '\n' + email.get('additionalMessage', '')
              subject = email.get('subject', alarm_msg)
              fa_ver = check_email(from_adr)
              tas_ver = check_emails(to_adrs)
              ccas_ver = check_emails(cc_adrs)
              bccas_ver = check_emails(bcc_adrs)
              if (fa_ver and tas_ver and ccas_ver and bccas_ver):
                ses.send_email(Source=from_adr,
                               Destination={'ToAddresses': to_adrs, 'CcAddresses': cc_adrs, 'BccAddresses': bcc_adrs},
                               Message={'Subject': {'Data': subject}, 'Body': {'Text': {'Data': msg}}})
                logger.info('Emails have been sent')

            logger.info('Start Sending SNS message to SMS')
            sns_configs = event.get('smsConfigurations', [])
            for sns_config in sns_configs:
              sns_msg = default_msg + '\n' + sns_config.get('additionalMessage', '')
              phone_numbers = sns_config.get('phoneNumbers', [])
              sender_id = sns_config.get('senderId')
              for phone_number in phone_numbers:
                  if check_phone_number(phone_number):
                    if check_value(sender_id):
                      sns.publish(PhoneNumber=phone_number, Message=sns_msg, MessageAttributes={'AWS.SNS.SMS.SenderID':{'DataType': 'String','StringValue': sender_id}})
                    else:
                      sns.publish(PhoneNumber=phone_number, Message=sns_msg)
                    logger.info('SNS messages have been sent')
```