Credentials
| Field | Where to find it |
|---|---|
| API security key | In the NMI merchant portal under Settings → Security Keys. Create a private key with the API permission. |
| Processor ID | Only if your account has several processors and you want a specific one. |
NMI uses the same address for test and production; your test account’s key makes a sandbox gateway. Test connection checks the key without a transaction.
Operations
| OrderCard | NMI type |
|---|---|
| Purchase | sale |
| Authorize | auth |
| Capture | capture |
| Void | void |
| Refund | refund |
| Verify | validate |
Merchant-initiated and recurring charges are sent as stored-credential charges, referencing the card’s first customer-initiated transaction.
Surcharging
OrderCard adds the surcharge from the rate set on the gateway and sends it in NMI’s surcharge field, with the total in amount.
3-D Secure
A 3-D Secure result sent with a charge goes in NMI’s cardholder_auth field (verified for status Y, attempted for A), with cavv, three_ds_version and directory_server_id. A 3-D Secure 1 result also sends xid. NMI sets the ECI itself from cardholder_auth.