[1]

Stripe API Reference (2015-08-29 17:39:09 +09:00 版) https://stripe.com/docs/api#idempotent_requests

To safely retry an API request without accidentally performing the same operation twice, you can attach a unique key to any POST request made to the Stripe API via the Idempotency-Key: <key> header.

[2]

Stripe API Reference (2016-12-16 17:59:49 +09:00) https://stripe.com/docs/api#idempotent_requests

To perform an idempotent request, attach a unique key to any POST request made to the API via the Idempotency-Key: <key> header.

[3] Stripe API Reference - Idempotent Requests, 2021-01-21T04:44:29.000Z https://stripe.com/docs/api/idempotent_requests?lang=curl