Idempotency

Send an Idempotency-Key header on POST requests. JCPay caches the first successful response for 24 hours and replays it verbatim on subsequent requests with the same key.

curl -X POST https://jcpay.innoserver.cloud/v1/payments \
  -H "Idempotency-Key: 8f4a2c17-b1d3-4e2f-8a9b-3c5d4e6f7a8b" \
  ...

If a duplicate request arrives while the first is still processing, the duplicate returns 409 conflict. Retry after a moment.

Best practice: use a UUID v4 per logical request. Never reuse a key across different requests — it will return stale data.