Refunds credit your wallet. The request_id is meant to make a refund idempotent — replaying the same one should be a no-op. The server ignores it, so every replay credits again.
A gift card is single-use. Redemption reads the "committed" flag, credits, then commits — but there is a gap between the check and the commit. Two redeems of the same code that arrive inside that gap both succeed. Submit GIFT-250 twice quickly.
GIFT-250 · value 250 · committed: False · redeemed 0x