Backtest a cost alert before it goes live
Preview how often an alert would have fired over the past weeks before turning it on, so alerts stay rare and useful.
Runs in
Claude · Slack
First optimization recommendation
The next day
ROI
Pays for itself with the first recommendation you act on
Playbook
What the agent does
From what Costory notices to what you decide. Costory suggests the next step in conversation, and you decide whether to go ahead.
Costory notices
A new alert is proposed, by you or by the agent.
Costory investigates
01
Describe the condition
For example a rolling 7-day sum above a threshold, or a jump versus the trailing average.
02
Backtest
preview_alert returns firing days, per-group fires and the notification count after dedup.
03
Tune
Adjust thresholds and grouping until the alert fires only when it matters.
04
Create
Send it to the right Slack or Teams channel.
Where you see it
Claude
You decide
You approve the alert after seeing how often it would have fired.
Why it matters
Most cost alerts are either too noisy or never fire. Teams mute them within a month.
Who it’s for
Platform engineers, FinOps leads
Where it runs
Claude · Slack
What you get
What lands in front of your team
Fewer false alarms
Thresholds tuned on your history.
Per-group alerts
One alert covers every team.
The right channel
Slack, Teams or email.
Sources and assistants
What it connects
Data sources
Example prompts
Or drive it yourself
Backtest
Backtest an alert on EC2 spend per team that fires when daily cost rises more than 25% above the trailing 7 days. How often would it have fired?
FAQ
Questions about this playbook
How fresh is the data?
Costory refreshes billing data every morning. Providers deliver billing exports with some delay, so a change usually shows up within a day or two.
How long does this playbook take to set up?
Connecting your billing data and the Costory MCP takes under 30 minutes with Terraform or CloudFormation. The playbook itself takes minutes: pick the scope, the trigger and the Slack channel. The first billing data lands the next day, and the agent starts from there.
Can we adjust what the agent does?
Yes. You choose the trigger, the scope (team, service, environment), the channel and the format, and you can pause or change it at any time.
Does Costory change anything in our cloud accounts?
No. Costory reads billing exports and the metrics you connect, and has no write access to your cloud. Actions it takes create Costory objects only: alerts, reports, dashboards and events. Your team stays in control of every change.
Step-by-step guide in the Costory docs
Related playbooks
Run these alongside it
Costory notices
A team's spend deviates from its baseline.
Route cost alerts to the owning team's channel
Each team gets its own alerts in its own Slack or Teams channel, scoped to the services it owns.
See the playbook
Costory notices
Spend on a team, service or account deviates from its baseline.
Investigate a cost spike and find the deploy behind it
When spend moves, the agent finds the deploy, team and service behind it, checks incidents and provider events from the same window, and posts the likely cause.
See the playbook
Costory notices
A team's forecast crosses a budget threshold.
Team budgets with forecast-based alerts
Monthly budgets per team, with Slack or email alerts when actual spend or the end-of-month forecast crosses a threshold.
See the playbook
Put this playbook on call
Included in every plan, from €250/month. 30-day free trial: connect in under 30 minutes, get your first optimization recommendation the next day.
First optimization recommendation
The next day
ROI
Pays for itself with the first recommendation you act on
Setup
About 30 minutes
Data residency
EU
Access
Read-only on your cloud