curl --request POST \
--url https://testapi.fractalpay.com/api/v1/preauth/update \
--header 'Authorization: Basic <encoded-value>' \
--header 'Content-Type: application/json' \
--data '
{
"merchant_key": "{{merchant_key}}",
"transaction_id": "txn_77c9a625a3",
"last_authorized_amount": "10.00",
"new_authorized_amount": "11.00",
"order_id": "5467"
}
'{
"result": true,
"message": "Amount Updated Successfully",
"data": {
"Status": "Approved",
"Account": "0043",
"Brand": "Visa",
"AuthCode": "",
"Authorized": "11.00",
"transaction_id": "txn_77c9a625a3",
"orderid": "5467"
}
}Update Pre-Authorization
Increases or decreases the authorized amount on an existing preauthorization. If new_authorized_amount is greater than last_authorized_amount, an incremental authorization is issued and a preauth.increment webhook fires. If new_authorized_amount is less, a partial reversal is issued and a preauth.decrement webhook fires. last_authorized_amount must match the current authorized amount on the record.
curl --request POST \
--url https://testapi.fractalpay.com/api/v1/preauth/update \
--header 'Authorization: Basic <encoded-value>' \
--header 'Content-Type: application/json' \
--data '
{
"merchant_key": "{{merchant_key}}",
"transaction_id": "txn_77c9a625a3",
"last_authorized_amount": "10.00",
"new_authorized_amount": "11.00",
"order_id": "5467"
}
'{
"result": true,
"message": "Amount Updated Successfully",
"data": {
"Status": "Approved",
"Account": "0043",
"Brand": "Visa",
"AuthCode": "",
"Authorized": "11.00",
"transaction_id": "txn_77c9a625a3",
"orderid": "5467"
}
}Authorizations
Use your Fractal API credentials.
Username = Client ID Password = Secret Key
Sandbox credentials can be generated from the Test Portal.
Body
The merchant's unique API key.
"{{merchant_key}}"
The guid of the existing preauthorization to update. Always use the original preauthorization transaction ID — not the ID returned by a previous update.
"txn_77c9a625a3"
The current authorized amount. Must match the amount on record or the request returns an Amount mismatch error.
"10.00"
The target authorized amount. Greater than last_authorized_amount triggers an increment; less triggers a decrement.
"11.00"
Your order reference.
"5467"