Billing Alarm
Four CloudWatch billing alarms — $10 / $50 / $100 monthly plus a $5/day spike detector — publishing to one SNS email topic. Must be deployed in us-east-1.
What you can build with this
A spend safety net for the whole AWS account. AWS publishes an EstimatedCharges metric (total month-to-date spend, updated a few times a day); the three monthly alarms email you as it crosses $10, $50, and $100, and the Daily Spend alarm uses metric math (day-over-day DIFF) to catch a single-day spike of $5+ even while total spend is still under every monthly threshold. Costs ~nothing itself: 4 alarms fit inside CloudWatch's always-free tier of 10, and the first 1,000 SNS emails per month are free.
Deployment timing
After you run the deploy command, resources come online at different times. Check the validation steps in order.
| Resource | Ready in |
|---|---|
| Stack (SNS topic + 4 alarms) | 1–2 min |
| Email delivery active | Immediately after you click "Confirm subscription" |
| First billing datapoint (alarms leave INSUFFICIENT_DATA) | Up to 24 h |
| Ongoing metric updates | A few times per day (~every 6 h) |
CloudFormation parameters
These are the values you will fill in when deploying the exported template. Changing these does not break the template — that is the point.
| Parameter | What to provide | Example |
|---|---|---|
| Environment | Environment tag applied to resources (does not rename them) | dev |