Web Integration Guide v1.1.2

1. Change Log

1.1 V1.0.0

Initial release.

1.2 V1.0.1-V1.0.7

(Removed)

1.3 V1.0.9

Specify transaction options for DPT DIRECT and DPT HOSTED mode.

1.4 V1.0.10

Update transaction options for WECHATPAY DIRECT (JSAPI) mode.

1.5 V1.0.11

Update transaction options for ALIPAY DIRECT (WAP) mode.

1.6 V1.0.12

Update transaction options for ALIPAY DIRECT (APP, MINI_APP) mode.

1.7 V1.1.0

Introduce card tokenization supportability for Customer-Initiated Transactions (CIT) and Merchant-Initiated Transactions (MIT) for DIRECT mode.

• New APIs to support card token creation, retrieval, and deletion.
• Update transaction options for DIRECT mode.

1.8 V1.1.1

• Specify transaction options for DPT DIRECT and DPT HOSTED mode to support fraud detection.
• Adjusted formatting

1.9 V1.1.2

• Updated parameter descriptions for WECHATPAY DIRECT (JSAPI) mode and added parameter descriptions for WECHATPAY DIRECT (MWEB) mode
• Added detailed explanation of the returnUrl parameter in Appendix 9.8 to clarify its usage and integration process.

2. PCI Compliance

To accept card payment in Direct Mode, you must submit a copy of your PCI-DSS certificate (for all relevant SAQs) to FOMO Pay to clear relevant compliance requirements.

For more information for SAQs, please visit:
https://www.pcisecuritystandards.org/documents/Understanding_SAQs_PCI_DSS_v3.pdf

3. Sequence Diagram

3.1 Hosted Mode

3.2 Direct Mode

4. Security and Encryption

4.1 Transport Security

Transport Layer Security (TLS) 1.2

4.2 Message Authentication

RFC 7617 HTTP Basic Authentication (https://tools.ietf.org/html/rfc7617)

The following key is required:

1. MID (<MID>) generated by FOMO Pay.
2. Pre-Shared Key (<PSK>) generated by FOMO Pay.

Please ensure <PSK>never leaves your server and managed by trusted parties only. Failing to do so will result in unauthorized access to your account. If you believe your <PSK>is lost, contact FOMO Pay immediately.

HTTP Authorization header is required in all requests. The Authorization header is constructed as follow.

Authorization: <AuthorizationType> <BasicCredentials>

<AuthorizationType>: fixed value Basic (without quote).

<BasicCredentials>: generated as follow.

Base64(<MID>:<PSK>)

Example:

Merchant setup:

Calculation:

Calculate <BasicCredentials> from:

Base64("100000000000001:E00F270DE323E2B187532D8E4B306EB2841AF0BFF08132BAB7F0E62BED6419BB")

Which yields:

MTAwMDAwMDAwMDAwMDAxOkUwMEYyNzBERTMyM0UyQjE4NzUzMkQ4RTRCMzA2RUIyODQxQUYwQkZGMDgxMzJCQUI3RjBFNjJCRUQ2NDE5QkI=

Authorization header:

Authorization: Basic MTAwMDAwMDAwMDAwMDAxOkUwMEYyNzBERTMyM0UyQjE4NzUzMkQ4RTRCMzA2RUIyODQxQUYwQkZGMDgxMzJCQUI3RjBFNjJCRUQ2NDE5QkI=

Include Authorization header in every request you send to FOMO Pay. Never include this header when you send request to other non-FOMO Pay servers.

5. Symbols and Abbreviated Terms

5.1 Required Flag

6. Message Types and Specification

6.1 Create an Order (Hosted Mode)

curl -X POST "https://ipg.fomopay.net/api/orders" \  -H "Content-Type: application/json" \  -d '{    "mode": "HOSTED",    "orderNo": "WEB-ORDER-10001",    "subject": "FOMO Pay Demo Order",    "description": "Hosted checkout example",    "amount": "10.00",    "currencyCode": "SGD",    "notifyUrl": "https://merchant.example.com/payments/notify",    "returnUrl": "https://merchant.example.com/payments/return",    "backUrl": "https://merchant.example.com/payments/cancel",    "sourceOfFunds": [      "CARD",      "PAYNOW"    ]  }'

{
  "id": "ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9",
  "subMid": "100000000000002",
  "orderNo": "WEB-ORDER-10001",
  "mode": "HOSTED",
  "subject": "FOMO Pay Demo Order",
  "description": "Hosted checkout example",
  "amount": "10.00",
  "currencyCode": "SGD",
  "status": "CREATED",
  "createdAt": 1711977000,
  "notifyUrl": "https://merchant.example.com/payments/notify",
  "returnUrl": "https://merchant.example.com/payments/return",
  "backUrl": "https://merchant.example.com/payments/cancel",
  "primaryTransactionId": "txn_01HQZ6T50Y7Y8FQ40R8Q9MZ7XM",
  "url": "https://pay.fomopay.net/redirect/ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9"
}

{
  "id": "ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9",
  "subMid": "100000000000002",
  "orderNo": "WEB-ORDER-10001",
  "mode": "HOSTED",
  "subject": "FOMO Pay Demo Order",
  "description": "Hosted checkout example",
  "amount": "10.00",
  "currencyCode": "SGD",
  "status": "CREATED",
  "createdAt": 1711977000,
  "notifyUrl": "https://merchant.example.com/payments/notify",
  "returnUrl": "https://merchant.example.com/payments/return",
  "backUrl": "https://merchant.example.com/payments/cancel",
  "primaryTransactionId": "txn_01HQZ6T50Y7Y8FQ40R8Q9MZ7XM",
  "url": "https://pay.fomopay.net/redirect/ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9"
}

{
  "hint": "req_01HQZ6PXG1PF1R2S1P33H0M2KJ",
  "code": "INVALID_REQUEST",
  "message": "orderNo already exists"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

6.2 Create an Order - (Direct Mode)

curl -X POST "https://ipg.fomopay.net/api/orders" \  -H "Content-Type: application/json" \  -d '{    "mode": "HOSTED",    "orderNo": "WEB-ORDER-10001",    "subject": "FOMO Pay Demo Order",    "description": "Hosted checkout example",    "amount": "10.00",    "currencyCode": "SGD",    "notifyUrl": "https://merchant.example.com/payments/notify",    "returnUrl": "https://merchant.example.com/payments/return",    "backUrl": "https://merchant.example.com/payments/cancel",    "sourceOfFunds": [      "CARD",      "PAYNOW"    ]  }'

{
  "id": "ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9",
  "subMid": "100000000000002",
  "orderNo": "WEB-ORDER-10001",
  "mode": "HOSTED",
  "subject": "FOMO Pay Demo Order",
  "description": "Hosted checkout example",
  "amount": "10.00",
  "currencyCode": "SGD",
  "status": "CREATED",
  "createdAt": 1711977000,
  "notifyUrl": "https://merchant.example.com/payments/notify",
  "returnUrl": "https://merchant.example.com/payments/return",
  "backUrl": "https://merchant.example.com/payments/cancel",
  "primaryTransactionId": "txn_01HQZ6T50Y7Y8FQ40R8Q9MZ7XM",
  "url": "https://pay.fomopay.net/redirect/ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9"
}

{
  "id": "ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9",
  "subMid": "100000000000002",
  "orderNo": "WEB-ORDER-10001",
  "mode": "HOSTED",
  "subject": "FOMO Pay Demo Order",
  "description": "Hosted checkout example",
  "amount": "10.00",
  "currencyCode": "SGD",
  "status": "CREATED",
  "createdAt": 1711977000,
  "notifyUrl": "https://merchant.example.com/payments/notify",
  "returnUrl": "https://merchant.example.com/payments/return",
  "backUrl": "https://merchant.example.com/payments/cancel",
  "primaryTransactionId": "txn_01HQZ6T50Y7Y8FQ40R8Q9MZ7XM",
  "url": "https://pay.fomopay.net/redirect/ord_01HQZ6Q3F1WB4G3WQ7D6A0S9R9"
}

{
  "hint": "req_01HQZ6PXG1PF1R2S1P33H0M2KJ",
  "code": "INVALID_REQUEST",
  "message": "orderNo already exists"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

6.3 Query an Order

curl -X GET "https://ipg.fomopay.net/api/orders/string"

{
  "id": "ord_01HQZ8BMN9KQXFM5T7RM0Q45Q0",
  "subMid": "100000000000002",
  "orderNo": "WEB-ORDER-10002",
  "mode": "DIRECT",
  "subject": "Direct payment example",
  "description": "Direct mode payment",
  "amount": "10.00",
  "currencyCode": "SGD",
  "status": "SUCCESS",
  "createdAt": 1711977300,
  "notifyUrl": "https://merchant.example.com/payments/notify",
  "returnUrl": "https://merchant.example.com/payments/return",
  "primaryTransactionId": "txn_01HQZ8CVAJX0B1AAYTRM4Q2FRJ",
  "codeUrl": "000201010212520400005303702540510.005802SG5913FOMO PAY DEMO6009Singapore6304ABCD",
  "threeDSecure": false
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "req_01HQZ8M7SC7V7SCMNH3DG7J8WW",
  "code": "ORDER_NOT_FOUND",
  "message": "orderId does not exist"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

6.4 Create a Refund Transaction - Request

curl -X POST "https://ipg.fomopay.net/api/orders/string/transactions" \  -H "Content-Type: application/json" \  -d '{    "type": "REFUND",    "originalId": "txn_01HQZ8CVAJX0B1AAYTRM4Q2FRJ",    "transactionNo": "REFUND-10001",    "amount": "10.00",    "currencyCode": "SGD",    "subject": "Refund for order WEB-ORDER-10001"  }'

{
  "id": "txn_01HQZ9M3DHK9C6SJQ5RHB94W8M",
  "type": "REFUND",
  "originalId": "txn_01HQZ8CVAJX0B1AAYTRM4Q2FRJ",
  "transactionNo": "REFUND-10001",
  "subject": "Refund for order WEB-ORDER-10001",
  "status": "CREATED",
  "createdAt": 1711977600,
  "amount": "10.00",
  "currencyCode": "SGD"
}

{
  "id": "txn_01HQZ9M3DHK9C6SJQ5RHB94W8M",
  "type": "REFUND",
  "originalId": "txn_01HQZ8CVAJX0B1AAYTRM4Q2FRJ",
  "transactionNo": "REFUND-10001",
  "subject": "Refund for order WEB-ORDER-10001",
  "status": "CREATED",
  "createdAt": 1711977600,
  "amount": "10.00",
  "currencyCode": "SGD"
}

{
  "hint": "req_01HQZ9H3A0N4X5P5A3D5SPX29V",
  "code": "REFUND_AMOUNT_EXCEEDED",
  "message": "refund amount exceeds remaining refundable amount"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

6.5 Query a Transaction

curl -X GET "https://ipg.fomopay.net/api/orders/string/transactions/string"

{
  "id": "txn_01HQZ9M3DHK9C6SJQ5RHB94W8M",
  "type": "REFUND",
  "originalId": "txn_01HQZ8CVAJX0B1AAYTRM4Q2FRJ",
  "transactionNo": "REFUND-10001",
  "subject": "Refund for order WEB-ORDER-10001",
  "status": "SUCCESS",
  "createdAt": 1711977600,
  "amount": "10.00",
  "currencyCode": "SGD",
  "sourceOfFund": "CARD"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "req_01HQZAGD7B2PQJ4GH9T2NEV5CS",
  "code": "TRANSACTION_NOT_FOUND",
  "message": "transactionId does not exist"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

{
  "hint": "string",
  "code": "string",
  "message": "string"
}

6.6 Retrieve Orders

Request

URL

https://ipg.fomopay.net/api/orders?filter=[filter]&range=[range]&sort=[sort]

[filter] (JSON object converted to string)

[range] (JSON list converted to string)

[sort] (JSON list converted to string)

Method

GET

Example:

Retrieve first 10 orders after 20th order created between 1/Jan/2020 00:00 (GMT+8) and 2/Jan/2020 00:00 (GMT+8) with status SUCCESS.

Perform URL encode

Form final URL to query

https://ipg.fomopay.net/api/orders?filter=%7B%22since%22%3A1577808000%2C%22till%22%3A1577894400%2C%22status%22%3A%22SUCCESS%22%7D&range=%5B20%2C30%5D&sort=%5B%22createdAt%22%2C%22ASC%22%5D

Response

When HTTP status code is not 2xx and not 5xx

When HTTP status code is 2xx

Header

Body

A list of objects in JSON. Each object has the following fields

6.7 Retrieve Transactions in an Order

Request

URL

https://ipg.fomopay.net/api/orders/[orderId]/transactions?filter=[filter]&range=[range]&sort=[sort]

[filter] (JSON object converted to string)

[range] (JSON list converted to string)

[sort] (JSON list converted to string)

Method

GET

Example:

Retrieve first 5 refund transactions after 5th transaction with status SUCCESS for order 100500020200101000000000.

Perform URL encode

Form final URL to query

https://ipg.fomopay.net/api/orders/100500020200101000000000/transactions?filter=%7B%22type%22%3A%22REFUND%22%2C%22status%22%3A%22SUCCESS%22%7D&range=%5B5%2C10%5D&sort=%5B%22createdAt%22%2C%22ASC%22%5D

Response

When HTTP status code is not 2xx and not 5xx

When HTTP status code is 2xx

Header

Body

A list of objects in JSON. Each object has the following fields

6.8 Create Token for Credit Card

Request

Response

Request Body

Response Body

Response Status Code

Example:

Request Body

{
  "type": "card",
  "card": {
    "number": "4417123456789113",
    "expiryYear": "28",
    "expiryMonth": "08",
    "nameOnCard": "First Last Name"
  }
}

Response Body

{
  "id": "c19JQHRQyWvgVNKPevtt25fR1p",
  "type": "card",
  "card": {
    "number": "441712xxxxxx9113",
    "expiryYear": "28",
    "expiryMonth": "08",
    "nameOnCard": "First Last Name"
  }
}

6.9 Get Token

Request

Response

Request Body

N/A

Response Body

Response Status Code

6.10 Delete Token

Request

Response

Request Body

N/A

Response Body

N/A

Response Status Code

7. Transaction Status Update Notification

A transaction status update will be sent to client server when any transaction status has changed.

7.1 Security

FOMO Pay will send notification to webhook URL using HTTP POST method in the following format:

Content-Type: application/json
X-FOMOPay-Authorization: FOMOPAY1-HMAC-SHA256 <HMACCredentials>

<payload>

The <HMACCredentials> is in following format (field order might change):

Version=1.1,Credential=<MID>,Nonce=<Nonce>,Timestamp=<Timestamp>,Signature=<Signature>

The verification algorithm is as follows:

1. Client extracts the following HTTP headers from HTTP request.

1. If one or more conditions of the following does not satisfy, reject the request.

• [version] is 1.1
• [credential] is your <MID>
• [nonce] has a length between 16-64 and was not used by gateway notification within 300 seconds
• [timestamp] (UNIX timestamp in seconds) within ±300 seconds of current time

1. Client reads request body [payload] from HTTP request.
2. Client concatenates [payload], [timestamp] and [nonce] to get string [message] to be verified.
3. Client calculate signature (in lowercase hexadecimal) with HMAC-SHA256 using <PSK> as key and [message] as message.
4. Reject if the calculated signature does not match [signature].

Example:

Merchant setup:

Notification received at notifyUrl:

Assume current time is 1/Jan/2020 00:02 (GMT+8)

Content-Type: application/json
X-FOMOPay-Authorization: FOMOPAY1-HMAC-SHA256 Version=1.1,Credential=100000000000001,Nonce=b39c7ec8fa58be1041eb3921c9ceb98b,Timestamp=1577808000,Signature=596ecb8f2636ff88eea7b4d4b4841ae822eaa4f1eea9cb1ce1da2953c9db0b05

{"orderId":"100500020200101000000000","orderNo":"order-20200101-000005","transactionId":"100510120200101000000000","transactionNo":"partialrefund-02"}

Verification:

1. Client extracts the following data from HTTP request.

[version] = 1.1
[credential] = 100000000000001
[nonce] = b39c7ec8fa58be1041eb3921c9ceb98b
[timestamp] = 1577808000
[signature] = 596ecb8f2636ff88eea7b4d4b4841ae822eaa4f1eea9cb1ce1da2953c9db0b05

1. Verify the following conditions.

• [version] is 1.1 (true)
• [credential] is your <MID> (true)
• [nonce] has a length between 16-64 and was not used by gateway notification within 300 seconds (true)
• [timestamp] (UNIX timestamp in seconds) within ±300 seconds of current time (true)

1. Client reads request body [payload] from HTTP request (please DO NOT parse the JSON).

{"orderId":"100500020200101000000000","orderNo":"order-20200101-000005","transactionId":"100510120200101000000000","transactionNo":"partialrefund-02"}

1. Client concatenates [payload], [timestamp] and [nonce] to get string [message] to be verified.

{"orderId":"100500020200101000000000","orderNo":"order-20200101-000005","transactionId":"100510120200101000000000","transactionNo":"partialrefund-02"}1577808000b39c7ec8fa58be1041eb3921c9ceb98b

1. Client calculates signature (in lowercase hexadecimal) with HMAC-SHA256 using <PSK> as key and [message] as message.

Calculated signature = 596ecb8f2636ff88eea7b4d4b4841ae822eaa4f1eea9cb1ce1da2953c9db0b05

1. Reject if the calculated signature does not match [signature].

Calculated signature matches the [signature] received. Merchant server shall reply with HTTP 200 OK immediately at this point. Please continue your business logic after the reply is sent.

7.2 Notification Request

POST notifyUrl
Content-Type: application/json

notifyUrl is the callback URL provided in the order creation request.

7.3 Notification Response

HTTP Status Code

200

HTTP redirection will NOT be followed. HTTP status code 301 (Moved Permanently) or 302 (Found) will be considered as notification failure.

HTTP status code 204 (No Content) will also be considered as notification failure.

Response HTTP body shall not exceed 5 KiB in size, its content will be ignored.

Merchant server shall query latest order status / transaction status using orderId and transactionId received depending on needs.

8. Fraud Detection

High-risk merchants who need to process card payments and perform fraud detection might be required to provide the following fields, and we will handle the fraud detection process.

This section is intended to provide specific clarification on the fraud detection process. These fields are specifically highlighted here as they are required for enabling fraud detection. For detailed parameter integration, please refer to Appendices 9.4 and 9.5.

Direct Mode

Hosted Mode

9. Appendix

9.1 List of Source of Fund

9.2 Order Status

9.3 Transaction Status

9.4 Transaction Options (HOSTED mode)

[1] Please find below for data types for each key.

[2] Please approach FOMO Pay for detailed KYC requirements.

9.5 Transaction Options (DIRECT mode)

[*] Please include returnUrl in request if url in Response Fields is mandatory or conditional.

[*] Transaction timeout may not work with some of the source of funds due to the following reasons. Do not infer transaction status even if the transaction appears to be timed out. Instead, always use transaction status retrieved from FOMO Pay.

• Some sourceOfFunds use different start time from order creation time for timeout calculations (which renders timeouts less useful)
• Some sourceOfFunds accept timeouts but do not follow timeouts accurately
• Some sourceOfFunds do not accept timeouts at all

[1] Zero-padding or leading zero is a valid and supported convention for representing months. E.g. Both “8” and “08” (for August) are supported.

[2] Description of 3-D Secure Options.

[3] Please approach FOMO Pay for configuration and instructions on getting openid.

[4] Response field will be an object named payReq in the following format.

[5] Response field will be an object named payReq in the following format.

[6] Please include returnUrl in request. Response field will be an object named payReq in the following format.

[7] Please approach FOMO Pay for detailed KYC requirements.

[8] Please find data types below for each key.

[9] Please find the allowed paymentMethodType below.

[10] Response field will be an object named payReq in the following format.

[11] Response field will be an object named payReq in the following format.

[12] txnType options will be based on whether a regular card transaction, customer-initiated transaction or a merchant-initiated transaction is done.

[13] Data types and fields for the card and token object. The card and token objects are used to initiate CIT or MIT transactions. It is recommended that only one; either the card or token object be sent at payload. If both are sent, the card object will take precedence to initiate the card transaction.

Card

Token

[14] Additional fields and specification for threeDSecure field for MIT.

[15] Sample request body for MITs

1st Transaction

where threeDSecure is enforced and merchantInitiated is false

{
  "mode": "DIRECT",
  "orderNo": "TEST_MIT001",
  "subject": "FOMOPAY UAT TEST",
  "description": "FOMOPAY UAT TEST",
  "backUrl": "https://fomopay.com/",
  "returnUrl": "https://fomopay.com/",
  "notifyUrl": "http://localhost:443",
  "currencyCode": "SGD",
  "amount": "12.34",
  "sourceOfFund": "CARD",
  "transactionOptions": {
    "timeout": 300,
    "txnType": "RECURRING",
    "ip": "167.163.152.53",
    "threeDSecure": "enforced",
    "merchantInitiated": false,
    "token": {
      "id": "c1FbwzRxQ6xMj3EWvydzkV0SkA"
    }
  }
}

2nd Transaction and onwards

where threeDSecure is disabled, merchantInitiated is true, and merchantInitiatedReason plus originalId (the primaryTransactionId of the 1st transaction) are required

{
  "mode": "DIRECT",
  "orderNo": "TEST_MIT002",
  "subject": "FOMOPAY UAT TEST",
  "description": "FOMOPAY UAT TEST",
  "backUrl": "https://fomopay.com/",
  "returnUrl": "https://fomopay.com/",
  "notifyUrl": "http://localhost:443",
  "currencyCode": "SGD",
  "amount": "12.34",
  "sourceOfFund": "CARD",
  "transactionOptions": {
    "timeout": 300,
    "txnType": "RECURRING",
    "ip": "167.163.152.53",
    "threeDSecure": "disabled",
    "merchantInitiated": true,
    "merchantInitiatedReason": "NO_SHOW",
    "token": {
      "id": "c1FbwzRxQ6xMj3EWvydzkV0SkA"
    },
    "originalId": "100510020231010227133206"
  }
}

[16] Please find the allowed payerType below.

[17] payer fields based on payerType.

9.6 Data Types

TPaymentAddress

TPaymentItem

[1] Please see below for amount format.

TBusiness

TBusinessID

TBusinessAddress

TIndividual

TIndividualID

TIndividualAddress

9.7 PayerUserAgent

Payer's http user-agent.

Mozilla/5.0 (iPhone; CPU iPhone OS 17_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.6 Mobile/15E148 Safari/604.1

9.8 returnUrl

The returnUrl parameter behaves differently for WeChatPay's JSAPI and MWEB integration modes.

1. JSAPI Mode：Optional

• If provided:
  FOMO Pay will host a payment landing page. After the user completes the payment on this page, they will be redirected to the specified returnUrl.
• If not provided:
  FOMO Pay will directly return the necessary parameters (TPayReqJsapi) for initiating the payment through WeChat's JSAPI. Merchants need to handle the payment flow using these parameters.

2. MWEB Mode：Not Supported

• The returnUrl parameter cannot be passed in MWEB mode. If provided, the request will be rejected.

For other sources of fund, returnUrl in request should be included if url in Response Fields is mandatory or conditional. See appendix 9.5.