Direct API Payment Integration
This document introduces the integration process of direct API payment integration mode.
In direct API integration mode, merchants need to build their own payment pages, such as cashier page, payment result page, etc. Therefore, this mode requires merchants to invest more R&D costs.
For more information about direct API integration mode, please refer to Overview of Integration Modes.
1. Integration Preparation
Upload test merchant public key，get the platform public key, AppID, test merchant number and other integration information；
Configure the callback address (WebHook), including the payment result callback address, refund result callback address, and so on;
Understand the principles of request message signing and verification, for generating a
signsignature string for each HTTP request Header.
2. Interaction Process
%%{init: {
'theme': 'base',
'themeVariables': {
'primaryColor': '#e6f0ff',
'primaryTextColor': '#333',
'primaryBorderColor': '#5b9bd5',
'lineColor': '#888',
'actorMargin': 40,
'noteBkgColor': '#0056b3',
'noteTextColor': '#ffffff',
'noteBorderColor': '#004a99'
}
}}%%
sequenceDiagram
participant User as User
participant Client as Merchant Client
participant MServer as Merchant Server
participant PMServer as PayerMax Server
participant Channel as Payment Channel
Wallet/Bank, etc.
%% 1. Order and Initiate Payment
User->>Client: 1.1 Select product and place order
Client-->>User: 1.2 Return merchant checkout page
User->>Client: 1.3 Fill in payment info
Confirm payment
Client->>MServer: 1.4 Initiate payment
MServer->>PMServer: 1.5 Create payment
Call Direct API payment interface
PMServer->>Channel: 1.6 Payment request
Channel-->>PMServer: 1.7 Return request result
PMServer-->>MServer: 1.8 Return request result
May include redirectURL
%% 2. Trigger User Authentication
rect rgb(235, 245, 255)
Note over User, Channel: User Authentication
MServer-->>Client: 1.9 Return request result
May include redirectURL
Client->>Client: 2.0 Redirect to redirectURL, initiate authentication
e.g., Wallet Login / 3DS Auth, etc.
User->>Client: 2.1 Enter authentication info
Client->>Channel: 2.2 Send authentication request
Channel->>Channel: 2.3 Authentication processing
Channel->>Client: 2.4 Redirect to merchant page
Channel->>PMServer: 3.1 Payment result notification
end
%% 3. Obtain Payment Result
rect rgb(235, 245, 255)
Note over MServer, PMServer: Obtain Payment Result
Note over MServer, PMServer: Via Payment Result Notification
PMServer->>MServer: 4.1 Asynchronous notification of payment result
MServer->>MServer: 4.2 Update payment status
MServer-->>PMServer: 4.3 Return response
Note over MServer, PMServer: Via Payment Order Query
MServer->>PMServer: 5.1 Query payment order
PMServer-->>MServer: 5.2 Return payment order information
MServer->>MServer: 5.3 Update payment status
end
%% 4. Display Results
Client->>MServer: 6.1 Get payment result
Client->>Client: 6.2 Display payment result
3. Interface List
| Associative Interaction Timing | Calling direction | Interface PATH |
| 1.3 Create a payment, call the cashier's order interface | Merchant -> PayerMax | /orderAndPay |
| 4.1 Asynchronous notification of payment results | PayerMax -> Merchant | /collectResultNotifyUrl |
| 5.1 Querying Payment Transactions | Merchant -> PayerMax | /orderQuery |
4. Environmental Information
Test environment request address：https://
pay-gate-uat.payermax.com/aggregate-pay/api/gateway/<Interface PATH>Integrated Environment：https://
pay-gate.payermax.com/aggregate-pay/api/gateway/<Interface PATH>
5. Integration Steps
5.1 Create Payment
Create a payment by callingDirect API Payment/orderAndPay API interface, initiating an HTTP POST request.
Note:
Merchants can specify the payment close time in seconds for a single payment via the interface entry expireTime, the value must be greater than 1800 (30 minutes) and less than 86400 (24 hours). If the value passed in is less than 1800, the system will reset to the minimum value of 30min; if the value passed in is greater than 86400, the system will reset to the maximum value of 86400. If the merchant does not specify it, the exact time to close the payment will be different depending on the payment method used.
Create Payment/orderAndPay API Example of an interface request:
curl --request POST \
--url https://pay-gate-uat.payermax.com/aggregate-pay/api/gateway/orderAndPay \
--header 'Accept: application/json' \
--header 'Content-Type: application/json' \
--header 'sign: FPFVT3o227JrFRbqu19boZCpVVTF9KznxyRawUmxpfXilHV/0yK46haPhAjNu1hPUMy7Vw/ILXhfzffNm4Fj0apWknlTY9OJxnSoQxS9BTFtc61tn5yV1q69x/kkBl82/qwg+XTJ4fOzy7Mar3VaC1E2PlDA6RkkKBUyNE6RYgsdB+Su7an4+4HVTNAnoe74WyvBgxTLMNg28igBTdqxaO3w/UBY6ObVp7vkqkQGdL1Y+HgmMYaAVwrM3+ALWGId0sJ+YqTY4WJ+0xCRGhaSnybiIjZsQEYyID68WNUfuavDLDsEhaMm/HfQvf5p0R1Ltovp3wwJnEbQcjY458iX5A==' \
--data '{
"version": "1.4",
"keyVersion": "1",
"requestTime": "2025-05-21T07:56:20.657+00:00",
"appId": "test81af1bdd45c4be5318305e279061",
"merchantNo": "TEST20118706753",
"data": {
"outTradeNo": "test598684645",
"subject": "Women's Long Skirts",
"integrate": "Direct_Payment",
"totalAmount": "74.99",
"currency": "USD",
"country": "AU",
"userId": "84645",
"language": "en",
"reference": "2476598332645",
"frontCallbackURL": "https://your.com/checkout-2/order-received/84645",
"notifyUrl": "https://your.com/?wc-api=wc_payermaxcallback",
"terminalType": "WEB",
"paymentDetail": {
"paymentMethodType": "CARD",
"cardInfo": {
"cardIdentifierNo": "455803****0807",
"cardHolderFullName": "test holder",
"cardExpirationMonth": "08",
"cardExpirationYear": "19",
"cvv": "808"
},
"buyerInfo": {
"firstName": "Deborah",
"lastName": "Swinstead",
"email": "your@gmail.com",
"phoneNo": "0609 031 114",
"address": "Test Address",
"city": "Holden Hill",
"region": "SA",
"zipCode": "5088",
"clientIp": "211.52.321.225",
"userAgent": "Mozilla/5.0 (iPad; CPU OS 18_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/22E252 [FBAN/FBIOS;FBAV/513.1.0.55.90;FBBV/735017191;FBDV/iPad13,16;FBMD/iPad;FBSN/iPadOS;FBSV/18.4.1;FBSS/2;FBID/tablet;FBLC/en_GB;FBOP/5;FBRV/737247184]"
}
},
"goodsDetails": [
{
"goodsId": "49373",
"goodsName": "Women's Long Skirts",
"quantity": "2",
"price": "38",
"goodsCategory": "skirt",
"showUrl": "https://your.com/product/womens-floral-print-elastic-high-waist-pleated-ruffle-flowy-long-skirts/"
}
],
"shippingInfo": {
"firstName": "test",
"lastName": "test",
"email": "test@gmail.com",
"phoneNo": "0609 031 114",
"address1": "Test Address",
"address2": "un",
"address3": "Test Address, SA 5088",
"city": "Holden Hill",
"region": "SA",
"state": "SA",
"country": "AU",
"zipCode": "5088"
},
"billingInfo": {
"firstName": "test",
"lastName": "test",
"email": "test@gmail.com",
"phoneNo": "0609 031 114",
"address1": "Test Address",
"address2": "un",
"address3": "Test Address, SA 5088",
"city": "Holden Hill",
"region": "SA",
"state": "SA",
"country": "AU",
"zipCode": "5088"
},
"envInfo": {
"deviceLanguage": "en-AU",
"screenHeight": "1180",
"screenWidth": "820"
}
}
}'Create Payment/orderAndPay API Example of an interface response:
{
"msg": "Success.",
"code": "APPLY_SUCCESS",
"data": {
"outTradeNo": "test598684645",
"tradeToken": "T20290323107917693601854",
"status": "SUCCESS"
}
}In order to protect the security of user payment, PayerMax or payment channels may initiate additional user authentication process, common ones are 3DS in card payment, user login for wallet payment and so on. If the user authentication is initiated, the interface response will additionally return redirectUrl and data.status=PENDING, and the user can use redirectUrl to redirect to the corresponding page, where the user can complete the authentication.
5.2 Jump to User Authentication
Create Payment/orderAndPay API The interface response redirectUrl indicates the user authentication page URL, after the merchant receives the response, it can redirect the jump, and the user completes the authentication information filling and submitting in this page.
5.3 Get Payment Result
5.3.1 Adoption of notification of payment results
See Get Payment Result Integration - Adoption of Payment Result Notification.
5.3.2 Inquiry via Payment Orders
See Get Payment Result Integration - Inquiry via payment order.
6. Test Go Live
After the merchant has completed the above integration steps, he/she can initiate the actual payment request for preliminary testing and validation, please refer to Integration Testing - Start a test for the specific steps.
After the test is passed and before the final release, the merchant must contact PayerMax technical support to submit the order information for the test so that PayerMax can check the request logs and data to confirm that you have correctly integrated the relevant capabilities, as described in Integration Testing - Initiate Acceptance.
After passing the acceptance test, the merchant can configure integration information for production environments and prepare for the opening of the volume.
In addition, under Acquiring Product Integration, there are integration documents for the various payment methods supported by PayerMax, which contain instructions for testing each payment method.
7. Troubleshooting
For response errors during testing or acceptance, you can refer to Troubleshooting - Error Code. Meanwhile, in FAQs, we summarize and list all kinds of common problems and how to deal with them.
You can also contact PayerMax technical support team directly for any questions during integration, testing and acceptance.