Credentials
Idempotency-Key
An HTTP header that lets LearnCoin's POST /v1/batches dedupe requests — two calls with the same key return the same batch ID.
The Idempotency-Key header is how LearnCoin's REST API prevents duplicate credential issuance from network retries. A tenant generates a UUID, sends it with the first POST /v1/batches request, and if the connection drops before the tenant sees the response, they retry with the same key — LearnCoin returns the same batch ID the second time instead of creating a duplicate batch.
The key is stored for 24 hours. Within that window, requests with the same key return the original response; after it, the key expires and a new request would create a fresh batch. The pattern is standard in modern APIs — Stripe popularized it — and fits the distributed-systems reality where clients don't always know whether a write succeeded.
LearnCoin's integration contract §6 requires every POST /v1/batches to include Idempotency-Key. Tenants that don't use it risk duplicate credentials from benign network events.