Безопасная проверка повторных запросов с PostgreSQL

Оригинал

Replay-Safe Verification with PostgreSQL

Email verification looks simple until a request times out at the worst possible moment. The API may have stored a token, queued a message, and then lost the connection before returning 201 Created. The client retries because it cannot tell whether the operation failed or only the response was lost. That retry is not a new intent; its a new delivery attempt. A useful backend design makes both attempts converge on one verification workflow. The result is fewer duplicate messages, fewer invalidate