Annotations

Annotations let you pin notes to specific dates on your cost timeline. Use them to document events that explain cost movements, like a new service deployment, a traffic spike, a pricing change, or a team restructuring.

When someone on your team investigates a cost spike weeks later, the annotation is already there with context.

Adding an annotation

Annotations are added manually. To create one:

1. Open the Playground or pre-made report and navigate to the date range where the event occurred.

2. Click the + below the bar on a singular day.

3. Enter a description of the event (e.g., "Migrated search indexing to OpenSearch," "Black Friday traffic spike," "Added 3 new dev accounts").

4. Save the annotation.

Annotations are visible to everyone on your team. They appear as markers on the cost timeline in both the Playground and in generated reports.

When to use annotations

Annotations are most useful when cost changes are driven by business decisions or operational events that billing data alone cannot explain. Common use cases:

Event type	Example annotation
Deployment	"Deployed new ML inference pipeline on p4d instances"
Traffic event	"Product Hunt launch, 5x normal traffic"
Team change	"Onboarded data team, 4 new accounts added"
Pricing change	"Switched RDS from on-demand to reserved"
Incident	"Redis cluster failover, 12 hours on backup instances"
External	"AWS price reduction for S3 Standard effective March 1"

Annotations vs. Anomaly Alerts

Annotations are manual and retrospective. You add them to explain something that already happened.

Anomaly Alerts are automatic and proactive. Pump detects unusual spend and notifies you. See Anomalies and Budget Alerts for details.

The two features complement each other: an anomaly alert tells you something changed, and an annotation records why.