Budgets & Cost

Cost is one of the five pillars, and Axis makes it observable: AtfBudget creates AWS Budgets with cost thresholds that publish to SNS, defaulting to reuse the observability alert topic so budget alerts land in the same Slack/Teams channel as everything else.

Why budget is off by default

AWS Budgets is account-global and us-east-1-bound. In a repo where the same example deploys across many nightly environments, budgets would collide — so the budget toggle defaults off in every starter and example. Turn it on deliberately, per account, when you want cost alerts.

cdk synth --context feature.budget=on

Topic reuse vs. dedicated

By default AtfBudget reuses the observability alert topic’s ARN from SSM (observability/alertTopicArn). If you have no observability stack, dedicatedTopic: true makes the budget stack mint its own topic and grant budgets.amazonaws.com publish rights.

Threshold tiers

Per-budget thresholds support cost, RI/SP-utilization, and usage budget types, each validated at synth. A malformed budget throws an [Axis] error rather than deploying a no-op alert.

Where to go next

• AtfBudget for the config surface.
• Observability & Alerting for the alert topic budget reuses.