curl --location --request POST '/offers//buy' \
--header 'Idempotency-Key;' \
--header 'Content-Type: application/json' \
--data-raw '{
"customer_id": "7f2a1b2c-1111-2222-3333-aaaaaaaaaaaa",
"quantity": 10
}'{
"purchase_id": "p-1234",
"status": "ACCEPTED",
"accepted_at": "2025-09-17T19:00:00Z"
}