1
Connect read-only
Add an AWS account through a cross-account IAM role (read-only). GCP and OCI use the same pattern. We never gain write access to your accounts.
read-only IAM · STS:AssumeRole
Savings History
A continuous, immutable log of every realised cost reduction — with the recommendation that triggered it, who applied it, and the cloud bill line that proves it.
- Weekly & monthly views
- Per-team attribution
- CSV / PDF export
lumicost.com — savings-history
By the numbers
Savings Historyin 4 numbers
totalCost + potentialSavings per account
0
daily cost snapshot
downsize · terminate · RI switch · …
0
recommendation types tracked
SHA-256, append-only
0
integrity hash chain
write access denied by design
0
ways to edit a past entry
How it works
Three steps. No agents. No surprises.
2
Apply or dismiss
When you act on a recommendation in Lumicost — apply, dismiss, send to Jira — we capture the actor, the resource id, and a JSON snapshot of the state before and after.
actor · resourceId · before/after
3
Snapshot the bill
Each day a CostHistory row records totalCost and potentialSavings per account. The audit log lets you trace each event back to the action that caused it.
daily · per-account
What's inside
A continuous, immutable log of every realised cost reduction — with the recommendation that triggered it, who applied it, and the cloud bill line that proves it.
01
Prove ROI to finance, not just engineering
Most FinOps tools tell you what you could save. Lumicost tells you what you actually saved. Every accepted recommendation is reconciled against the next billing cycle, so the ROI you report is the ROI that hit the bill.
02
Immutable, audit-ready timeline
Every entry in the history is append-only and cryptographically chained — useful for SOC 2 control CC7.2 (change management) and ISO 27001 A.12.1.2.
03
Attribution that survives reorgs
Saving credit follows the team that owned the resource at the moment of the action — not the team that owns it today. Reorgs no longer rewrite financial history.
Capabilities
Everything you need on day one.
- Daily cost & savings snapshot
- Append-only audit log
- SHA-256 integrity hash chain
- beforeState / afterState JSON diff
- Filter by user · entity · action
- Per-tenant isolation
- API access via API key
- Pairs with SIEM export (Enterprise)
Before vs after Lumicost
Night and day.
Without Lumicost
- 'Estimated savings' nobody can prove
- Console deletes events after a fixed window
- 'Did anyone touch this?' takes hours of Slack
With Lumicost
- Each action recorded with actor and JSON diff
- Append-only log under your tenant
- Filter by user, entity or action in seconds
Where teams use it
Three ways teams put it to work.
Quarterly board readout
Export a PDF showing $483K saved across 6 quarters, broken down by team and cloud — without spreadsheet archaeology.
Engineer performance reviews
Surface the 5 engineers who unlocked the most realised savings this half — with proof, not anecdotes.
Forecast vs. actual
Compare predicted vs. realised savings per recommendation type — so the next forecast is calibrated to your stack, not industry benchmarks.
From the field
“We chose append-only with a SHA-256 chain because savings without a paper trail are just a story. The audit log is the receipt.”
Plays nice with your stack
AWSGCPAzureOracle CloudKubernetesTerraformPulumiSlackJiraLinearGitHubGitLabDatadogSplunkOpenTelemetryPagerDutyNetSuiteSAPAWSGCPAzureOracle CloudKubernetesTerraformPulumiSlackJiraLinearGitHubGitLabDatadogSplunkOpenTelemetryPagerDutyNetSuiteSAP
FAQ
Frequently asked questions
How is the saving amount calculated?
We compare the cloud bill line for the affected resource in the 30 days before the change with the 30 days after, normalised by usage to remove organic growth or shrinkage.
Can the history be edited?
No. Entries are append-only. If a recommendation is later reversed, that produces a new entry — the original record is preserved.
Keep exploring
Try it free.
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