Generac AWS Notifier

Monitor your Generac generators and propane tank monitors with AWS EventBridge, Lambda, and receive notifications via SNS or SES when status changes occur.

This project is adapted from the ha-generac Home Assistant integration, repurposed as a standalone AWS service focused on status monitoring and notifications.

Features

• Automated Monitoring: Periodic checks of generator status via AWS EventBridge
• State Tracking: Stores previous state in DynamoDB to detect changes
• Flexible Notifications: Send alerts via SNS or SES (email)
• Comprehensive Alerts:
  • Generator status changes (Ready, Running, Exercising, etc.)
  • Connectivity changes
  • Maintenance alerts
  • Warning conditions
  • Low battery voltage
• Configurable: Customize check frequency and notification preferences
• Infrastructure as Code: Deploy with AWS SAM

Architecture

EventBridge Schedule (every 5 min)
           ↓
    Lambda Function
           ↓
    Generac API (MobileLink)
           ↓
    DynamoDB (state storage)
           ↓
    SNS/SES (notifications)

Prerequisites

1. Generac MobileLink Account: Active account at https://app.mobilelinkgen.com/
2. AWS Account: With permissions to create Lambda, DynamoDB, EventBridge, SNS, and SES resources
3. AWS SAM CLI: Install AWS SAM CLI
4. Python 3.13+: For local development/testing

Getting the Session Cookie

The Generac API requires authentication via a session cookie (username/password login is blocked by CAPTCHA):

1. Log into https://app.mobilelinkgen.com/ and navigate to one of your devices
2. Open browser Developer Tools (right-click → Inspect)
3. Go to the Network tab and refresh the page
4. Click the first request in the list (should match your device ID in the URL)
5. In the Headers tab, scroll down to find the Cookie field
6. Copy the entire cookie value (it will be very long, thousands of characters)

Important: Keep this cookie secure. Store it in AWS Secrets Manager or parameter store for production use.

Deployment

1. Clone the Repository

git clone https://github.com/landonix/generac-aws-notifier.git
cd generac-aws-notifier

2. Store Session Cookie in AWS Secrets Manager

Store your session cookie securely in AWS Secrets Manager:

aws secretsmanager create-secret \
  --name generac-notifier/session-cookie \
  --secret-string "YOUR_VERY_LONG_SESSION_COOKIE_HERE" \
  --region us-east-1

Important: Replace YOUR_VERY_LONG_SESSION_COOKIE_HERE with the actual cookie you copied from step 1.

3. Deploy with SAM

# Build the application
sam build

# Deploy with your email configuration
sam deploy \
  --guided \
  --parameter-overrides \
    SesToEmails="[email protected]" \
    SesFromEmail="[email protected]"

On first deployment, SAM will ask you questions:

• Stack name: generac-notifier (or choose your own)
• AWS Region: us-east-1 (or your preferred region)
• Confirm changes: Y
• Allow SAM CLI IAM role creation: Y
• Save arguments to configuration: Y

After the first deployment, you can simply run:

sam build && sam deploy

4. Verify Email Addresses (for SES)

If using SES in sandbox mode, you must verify recipient email addresses:

aws ses verify-email-identity --email-address [email protected]

Check your inbox for a verification email from AWS.

Configuration Options

Deployment Parameters

Parameter	Required	Default	Description
SecretName	No	generac-notifier/session-cookie	AWS Secrets Manager secret name containing session cookie
CheckSchedule	No	rate(5 minutes)	EventBridge schedule expression
SnsTopicArn	No	-	SNS topic ARN for notifications
SesFromEmail	No	-	From email address for SES
SesToEmails	No	-	Comma-separated recipient emails
NotifyOnStatusChange	No	true	Enable status change notifications
NotifyOnConnectivityChange	No	true	Enable connectivity notifications
NotifyOnMaintenanceAlert	No	true	Enable maintenance alert notifications
NotifyOnWarning	No	true	Enable warning notifications
NotifyOnLowBattery	No	true	Enable low battery notifications
LowBatteryThreshold	No	12.0	Battery voltage threshold (volts)

Schedule Expressions

Use rate or cron expressions for CheckSchedule:

• rate(5 minutes) - Every 5 minutes
• rate(1 hour) - Every hour
• cron(0 */6 * * ? *) - Every 6 hours
• cron(0 8 * * ? *) - Daily at 8 AM UTC

Monitoring

CloudWatch Logs

View Lambda execution logs:

sam logs -n GeneracMonitorFunction --tail

Or in the AWS Console:

1. Go to CloudWatch → Log groups
2. Find /aws/lambda/generac-notifier-monitor

Manual Invocation

Test the Lambda function manually:

aws lambda invoke \
  --function-name generac-notifier-monitor \
  --payload '{}' \
  response.json

cat response.json

DynamoDB State

View stored device states:

aws dynamodb scan --table-name generac-notifier-device-state

Notification Examples

Status Change

Subject: Generator Alert: Home Generator

Your Generator has reported status changes.

Device: Home Generator
Serial Number: ABC123456

Changes:
  • Status changed: Ready → Running

Current Status:
Status: Running
Connected: Yes
Battery: 13.2V

Timestamp: 2025-10-01T15:30:00Z

Low Battery

Subject: Generator Alert: Home Generator

Your Generator has reported status changes.

Device: Home Generator
Serial Number: ABC123456

Changes:
  • Battery voltage: 13.1V → 11.8V

Current Status:
Status: Ready
Connected: Yes
Battery: 11.8V
Low Battery Warning

Timestamp: 2025-10-01T15:35:00Z

Cost Estimates

Approximate AWS costs (us-east-1, as of 2025):

Service	Usage	Monthly Cost
Lambda	8,640 invocations (5 min intervals)	< $0.01
DynamoDB	On-demand, minimal storage	< $0.25
EventBridge	8,640 events	Free tier
SNS	1,000 notifications	< $0.50
SES	1,000 emails	$0.10
Total		< $1.00/month

Troubleshooting

Session Cookie Expired

If you receive SessionExpiredException errors:

1. Get a new session cookie from Generac MobileLink

2. Update the secret in AWS Secrets Manager:

   aws secretsmanager update-secret \
     --secret-id generac-notifier/session-cookie \
     --secret-string "NEW_COOKIE" \
     --region us-east-1

   The Lambda function will automatically use the new cookie on its next run.

No Notifications Received

1. Check Lambda logs for errors
2. Verify notification settings in parameters
3. For SES: Ensure email addresses are verified
4. For SNS: Check topic subscription confirmation

Lambda Timeout

If checks timeout with many devices:

1. Increase Lambda timeout in template.yaml (Globals → Function → Timeout)
2. Redeploy: sam build && sam deploy

Development

Local Testing

# Install dependencies
pip install -r requirements.txt

# Set environment variables
export GENERAC_SESSION_COOKIE="your_cookie"
export DYNAMODB_TABLE="test-table"

# Run tests
pytest tests/

Project Structure

generac-aws-notifier/
├── src/
│   ├── __init__.py
│   ├── lambda_handler.py      # Main Lambda entry point
│   ├── generac_api.py          # Generac API client
│   ├── models.py               # Data models
│   ├── config.py               # Configuration
│   ├── state_manager.py        # DynamoDB state management
│   └── notifier.py             # Notification logic
├── tests/                      # Unit tests
├── template.yaml               # SAM template
├── requirements.txt            # Python dependencies
└── README.md                   # This file

Cleanup

Remove all AWS resources:

sam delete

This will delete:

• Lambda function
• DynamoDB table (data will be lost!)
• EventBridge rule
• CloudWatch log group
• IAM roles

Credits

This project is adapted from the ha-generac Home Assistant integration by @binarydev, which was originally forked from @bentekkie.

Special thanks to the contributors of the original project for reverse-engineering the Generac MobileLink API.

License

MIT License - See LICENSE file for details

Disclaimer

This is an unofficial project and is not affiliated with, endorsed by, or connected to Generac Power Systems, Inc. Use at your own risk. The Generac MobileLink API is not publicly documented and may change without notice.