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Cloud bills contain millions of line items with no sense of priority. Digest surfaces only the cost changes that matter, ranked by real dollar impact, with AI-generated explanations for each one.
Costory Digest showing a cost breakdown tree with AI-generated summaries for each cost change

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Overview

Digest analyzes your cloud bill at the end of each period and produces a ranked breakdown of every significant cost change. Each change gets an AI-generated incident report from that explains what happened, what caused it, and whether it correlates with known events like deploys or pricing changes. Where it fits in your day-to-day:
  • Replacing manual monthly cost reviews with an automated, shareable report. See the monthly reporting guide.
  • Triaging cost anomalies before they become surprises in the next invoice
  • Giving executive stakeholders a summary they can read without digging into dashboards

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Key terms used in this article

  • Cost Breakdown Tree: The hierarchical structure Digest uses to organize cost data. You configure which dimensions form each level (e.g., Provider > Account > Service). Nodes auto-expand based on cost impact.
  • Billy: Costory’s AI FinOps assistant that analyzes billing data, detects anomalies, and generates incident reports for each node in the tree.
  • Node: A single segment in the cost breakdown tree (e.g., a specific AWS account or GCP service). Each node shows a summary of the cost change and its total dollar impact.
  • View: A saved Cost Explorer configuration. You can feed saved views into Digest for automated analysis.
See the Glossary for a full list of terms.

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Get started

1

Configure the cost breakdown tree

Set up how Digest breaks down your costs. You can change this configuration at any time.
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Current Period
The time window to analyze
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Reference Period
The comparison period to measure changes against
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Tree Structure
The dimensions that form each level of the breakdown. You can use standard columns or to split costs by team, product, or environment.
2

Review the ranked cost changes

Digest produces a tree of all cost changes, ranked by total dollar impact. Nodes auto-expand and auto-collapse based on their relevance, so you see the biggest movers first.
Digest cost breakdown tree showing cost changes ranked by dollar impact across providers and services
Each node includes a one-line summary and the total cost change. Click any node to open its detailed incident report.
3

Read Billy's incident reports

For each node, Billy generates a cost incident report that breaks down the change into:
  • Step changes: sudden shifts in cost level
  • Trends: gradual increases or decreases over time
  • Events: correlated deploys, pricing changes, or custom events
  • Root causes: the specific resources or configurations driving the change
Billy AI-generated cost incident report showing step changes, trends, and root cause analysis
You can edit any Billy-generated report to add your own context and annotations before sharing.
4

Schedule automated delivery

Configure Digest to run automatically on a schedule. Costory generates the report in the background and delivers it when ready, so the entire process is hands-off after the initial setup.
Digest automated scheduling configuration modal in Costory
5

Share with your team

Share a preview of the Digest via Slack or Microsoft Teams. Your team gets a summary of the biggest cost changes without needing to log into Costory.
Digest cost summary shared in a Slack channel showing top cost changes and AI explanations

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Use cases

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Monthly cost reviews

Configure Digest with [Provider, Account, Service] as your tree structure and run it at the end of each month. Share the executive summary with finance or leadership instead of building a report from scratch. See the Monthly Cloud Cost Reporting guide for more detail.

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Cost spike investigation

When an alert fires or someone flags a cost increase, open Digest with a narrower time range (e.g., this week vs. last week). The tree will surface which services and accounts drove the increase, and Billy’s incident reports will point to the likely root cause.

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Team-level cost accountability

Use Virtual Dimensions in the tree structure to break costs down by team. Each team lead can review their node and understand how their infrastructure spend changed, without needing to build their own queries.

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Frequently Asked Questions

You can configure Digest to run on any recurring schedule. Most teams run it monthly to align with billing cycles, but weekly or custom intervals are supported too.
Yes. The cost breakdown tree is fully configurable. You choose the dimensions (provider, account, service, team, environment) and can apply filters to scope the Digest to what matters to your team.
Yes. Digest pulls from all connected cloud providers. You can break down costs by provider as a top-level dimension or group cross-provider costs by service, team, or any other dimension.
Yes. Every Billy-generated report is editable. You can add annotations, context, or corrections before sharing with your team via Slack, Teams, or email.
Slack Reports send a scheduled snapshot of a specific Cost Explorer view to a Slack channel. Digest is broader: it automatically analyzes your entire cost structure, ranks changes by impact, and generates AI explanations for each one. Many teams use both, Digest for monthly reviews and Slack Reports for ongoing team-specific visibility.

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Next Steps

Automate Monthly Reporting

Replace manual monthly cost reviews with AI-generated reports

Cost Explorer

Drill into specific cost changes with full context

Automated Slack Reports

Send recurring cost snapshots to your team’s channels

Executive Cost Reports

Build the dashboards your leadership team wants to see

Decentralize FinOps

Give each squad ownership of their cloud costs

Automate Cloud Budgets

Define per-team budgets and automate alerts when teams exceed targets
Last modified on March 16, 2026