# Bug Report to Root Cause Brief Sample

## Root Cause Summary

The likely cause is a duplicate invoice-create event emitted during retry before idempotency state is fully committed.

## Severity

High - customer-facing financial duplication with operational impact.

## Impacted Users

- EU pilot merchants retrying checkout updates
- Finance operations handling reconciliation
- Support team fielding repeat tickets

## Fix Recommendation

Enforce idempotency before the retry path can emit a second invoice-create event.

## Prevention Steps

- Add retry/idempotency regression coverage
- Alert on duplicate invoice-create events
- Review retry timing around idempotency commit

## Owner

Billing engineering lead