idempotency key
termcloudweb dev
A unique token attached to a request so the server can safely ignore accidental duplicates.
When a client retries because it did not hear back, the idempotency key lets the server recognize "I already did this one" and not, say, charge the card twice. It is the practical mechanism that makes retries safe over an unreliable network.
Also known as: idempotency-key, idempotency token