Stripe Charging Twice? Add an Idempotency Key

A dropped connection or a retried webhook can cause the same payment request to fire more than once — without protection, Stripe processes each one as a separate, real charge.

The fix:

pass an Idempotency-Key header with a unique value per logical transaction. If the same key is sent twice, Stripe recognizes the duplicate and returns the original result instead of charging again. One header, and this entire failure mode goes away.