{"ok":true,"provider":"sumup","cutover":[],"webhook":{"url":"https://sumup.entroupix.com/webhook","expects":{"contentType":"application/json","method":"POST","example":{"payload":{"id":"chk_xyz123","checkout_reference":"ext_ref_001","transaction_id":"txn_456","client_transaction_id":"txn_456"}},"keyFields":[{"path":"payload.id","type":"string","meaning":"Primary transaction/checkout identifier; fallback to transaction_id or client_transaction_id if missing"},{"path":"payload.transaction_id","type":"string","meaning":"Alternative transaction identifier (reader/card transactions)"},{"path":"payload.checkout_reference","type":"string","meaning":"External reference provided at creation (externalReference in CreateChargeInput)"},{"path":"payload.client_transaction_id","type":"string","meaning":"Client transaction ID (used for reader/card; fallback identifier if id missing"}]}}}