RAMBOCARD GUIDE · 2026-07-29
RamboCard API Idempotency and Retry Safety for Card Issuing
How RamboCard API merchants should use idempotency keys to avoid duplicate cards, duplicate top-ups and duplicate ledger entries.
API overview
Every create-card and top-up operation needs an idempotency strategy before production launch.
RamboCard explains wallet funding, card issuing, card top-ups, service fees, notifications and reconciliation in one product workflow.
Why retries happen
Networks timeout, browsers resubmit, mobile connections drop and upstream issuers can return delayed results. Without idempotency, the same user action can create two cards or two card top-ups.
Recommended key design
Use a stable idempotency key per business action, not per HTTP retry. Store request payload hash, response status, created object and expiration window. Reject conflicting payloads that reuse the same key.
Ledger safety
Ledger entries should use business object IDs and event IDs so replaying an API response or webhook does not move money twice. Reserve deduction, quota consumption and card funding must be atomic.
User experience
If a retry is still processing, the user should see processing state instead of a second button click. If the upstream returns no card number, the platform should roll back local pre-deductions unless a usable card is confirmed.
Launch checklist
- Confirm the relevant RamboCard account, wallet, card, API merchant or transaction record before taking action.
- Keep RamboToken USDT wallet records, platform USD records, card balances and API merchant reserve records separate.
- Show fees, minimums, card program status and restrictions before the user confirms a financial operation.
- Send email notifications for material wallet movement, card charges, failed payments, low balance, refunds, chargebacks and card status changes where the platform receives the event.
- Use backend policy as the source of truth. Frontend pages should explain, display and refresh state, not create financial authority by themselves.
FAQ
Can idempotency be optional?
Not for production money movement. It is a core safety control.
How long should keys be stored?
Store them long enough to cover client retries, webhook delays and support review windows.
What if the same key has a different payload?
Reject it as a conflict to avoid unpredictable state.