a day ago
- The author investigates the first instance of idempotency keys, unique identifiers that ensure duplicate API messages are ignored.
- Claude AI initially claimed Stripe introduced idempotency keys around 2011, but later retracted, noting Stripe popularized the header circa 2015.
- Earlier concepts include Amazon EC2's ClientToken and the 2005 POST Once Exactly specification using unique POST URLs.
- Transport-level standards like OASIS ebXML and WS-ReliableMessaging also aimed at exactly-once processing via message deduplication.
- The earliest electronic example found is from Birrell and Nelson's 1984 paper on RPC at Xerox PARC, which used a call identifier to eliminate duplicate packets.
- Historical precursors like Incan quipu and tally sticks are mentioned but excluded as they don't involve electronic computers.