2 min read
Send a key per operation
Generate a unique key (a UUID) for each distinct write, and reuse that same key only when retrying that same request.
curl -sS -X POST https://hub.credicorp.co.uk/public/v1/enquiries \
-H 'Content-Type: application/json' \
-H 'Idempotency-Key: 5f2c9a1e-8b3d-4a7c-9e21-0d6f1b2c3a4e' \
-d '{"form":"contact-us","fields":{"consent":"yes"}}'What the server does
On first receipt it processes and records the result under the key. On a replay with the same key and same body, it returns the stored result — no duplicate. A same key with a different body returns 409 idempotency_key_reused.
Combine with backoff
Pair keys with jittered backoff so a timeout-then-retry is both safe and well-behaved.
Frequently asked questions
How long is a key remembered?
Long enough to cover a sensible retry window. Reuse the same key only for genuine retries of the identical request; generate a fresh key for anything new.
What if I reuse a key with a different body?
You get a 409 idempotency_key_reused. Keys are bound to the request they first accompanied. See that error.
Funding for UK limited companies
Credicorp lends to your company, not to you personally — short-term working capital with no personal guarantee. See what your business could access.