QFPay Payment API Skill

Overview

QFPay API is a comprehensive payment solution that offers various payment methods to meet the needs of different businesses. This skill provides complete API integration guidelines including environment configuration, request formats, signature generation, payment types, supported currencies, and status codes.

Environment Configuration

QFPay API is accessible via three main environments:

Environment	Base URL	Description
Sandbox	https://openapi-int.qfapi.com	For simulating payments without real fund deduction
Testing	https://test-openapi-hk.qfapi.com	Real payment flow but linked to test accounts (no settlement)
Production	https://openapi-hk.qfapi.com	Real live payments with actual settlement

Important Notes:

• Transactions in Testing environment using test accounts will NOT be settled
• Always ensure refunds are triggered immediately for test transactions
• Mixing credentials or endpoints across environments will result in signature or authorization errors

Environment Variables Setup

Configure these environment variables before using the API:

export QFPAY_APPCODE="your_app_code_here"
export QFPAY_KEY="your_client_key_here"
export QFPAY_MCHID="your_merchant_id"  # Optional, depends on account setup
export QFPAY_ENV="sandbox"  # Options: prod, test, sandbox

API Usage Guidelines

Rate Limiting

To ensure fair usage and optimal performance:

• Limit: Maximum 100 requests per second (RPS) and 400 requests per minute per merchant
• Exceeding Limit: API responds with HTTP 429 (Too Many Requests)

Best Practices

1. Batch Requests: Use batch processing to minimize individual requests
2. Efficient Queries: Utilize filtering and pagination
3. Caching: Implement response caching to avoid repeated requests
4. Monitoring: Track API usage and implement logging for request patterns

Error Handling

When receiving HTTP 429:

1. Pause further requests for a specified duration
2. Implement exponential backoff for retries
3. Log errors for monitoring

Traffic Spike Management

For anticipated traffic spikes (e.g., promotional events), contact:

• Technical Support: technical.support@qfpay.com

Request Format

HTTP Request

POST /trade/v1/payment

Public Payment Request Parameters

Attribute	Required	Type	Description
txamt	Yes	Int(11)	Transaction amount in cents (100 = $1). Suggest > 200 to avoid risk control
txcurrcd	Yes	String(3)	Transaction currency. See Currencies section for full list
pay_type	Yes	String(6)	Payment type code. See Payment Types section
out_trade_no	Yes	String(128)	External transaction number. Must be unique per merchant account
txdtm	Yes	String(20)	Transaction time format: YYYY-MM-DD hh:mm:ss
auth_code	Yes (CPM only)	String(128)	Authorization code for scanning barcode/QR. Expires within one day
expired_time	No (MPM only)	String(3)	QR expiration in minutes. Default: 30, Min: 5, Max: 120
goods_name	No	String(64)	Item description. Max 20 chars, UTF-8 for Chinese. Required for App payments
mchid	No	String(16)	Merchant ID. Required if assigned, must NOT be included if not assigned
udid	No	String(40)	Unique device ID for internal tracking
notify_url	No	String(256)	URL for asynchronous payment notifications

HTTP Header Requirements

Field	Required	Description
X-QF-APPCODE	Yes	App code assigned to merchant
X-QF-SIGN	Yes	Signature generated per signature algorithm
X-QF-SIGNTYPE	No	Signature algorithm. Use SHA256 or defaults to MD5

Content Specifications

• Character Encoding: UTF-8
• Method: POST/GET (depends on endpoint)
• Content-Type: application/x-www-form-urlencoded

Response Format

Success Response Structure

{
  "respcd": "0000",
  "respmsg": "success",
  "data": {
    "txamt": "100",
    "out_trade_no": "20231101000001",
    "txcurrcd": "HKD",
    "txstatus": "SUCCESS",
    "qf_trade_no": "9000020231101000001",
    "pay_type": "800101",
    "txdtm": "2023-11-01 10:00:00"
  }
}

Response Fields

Field	Type	Description
respcd	String(4)	Return code. "0000" means success
respmsg	String(64)	Message description of respcd
data	Object	Payment transaction data

Data Object Fields

Field	Type	Description
txamt	String	Transaction amount in cents
out_trade_no	String	Merchant's original order number
txcurrcd	String	Currency code (e.g., HKD)
txstatus	String	Payment status: SUCCESS, FAILED, PENDING
qf_trade_no	String	QFPay's unique transaction number
pay_type	String	Payment method code
txdtm	String	Payment time (YYYY-MM-DD HH:mm:ss)

Signature Verification

Response may include X-QF-SIGN and X-QF-SIGNTYPE headers. Verify by:

1. Extracting data fields in sorted order
2. Concatenating as key1=value1&key2=value2&...
3. Appending client key
4. Generating MD5 hash and comparing

Signature Generation

All API requests must include a digital signature in the HTTP header:

X-QF-SIGN: <your_signature>

Step-by-Step Guide

Step 1: Sort Parameters

Sort all request parameters by parameter name in ASCII ascending order.

Example:

Parameter	Value
mchid	ZaMVg12345
txamt	100
txcurrcd	HKD

Sorted result:

mchid=ZaMVg12345&txamt=100&txcurrcd=HKD

Step 2: Append Client Key

Append your secret client_key to the string.

If client_key = abcd1234:

mchid=ZaMVg12345&txamt=100&txcurrcd=HKDabcd1234

Step 3: Hash the String

Hash using MD5 or SHA256 (SHA256 recommended):

SHA256("mchid=ZaMVg12345&txamt=100&txcurrcd=HKDabcd1234")

Step 4: Add to Header

X-QF-SIGN: <your_hashed_signature>

Important Notes

• Do NOT insert line breaks, tabs, or extra spaces
• Parameter names and values are case-sensitive
• Double-check parameter order and encoding if signature fails

Code Examples

Python

import os
import hashlib

APPCODE = os.getenv('QFPAY_APPCODE')
KEY = os.getenv('QFPAY_KEY')

def generate_signature(params, key):
    """Generate MD5 signature"""
    keys = list(params.keys())
    keys.sort()
    query = []
    for k in keys:
        if k not in ('sign', 'sign_type') and (params[k] or params[k] == 0):
            query.append(f'{k}={params[k]}')
    
    data = '&'.join(query) + key
    md5 = hashlib.md5()
    md5.update(data.encode('utf-8'))
    return md5.hexdigest().upper()

def generate_signature_sha256(params, key):
    """Generate SHA256 signature"""
    keys = list(params.keys())
    keys.sort()
    query = []
    for k in keys:
        if k not in ('sign', 'sign_type') and (params[k] or params[k] == 0):
            query.append(f'{k}={params[k]}')
    
    data = '&'.join(query) + key
    sha256 = hashlib.sha256()
    sha256.update(data.encode('utf-8'))
    return sha256.hexdigest().upper()

Payment Types

The pay_type parameter specifies which payment method to use. This affects transaction routing and UI requirements.

Note: Not all pay_type values are enabled for every merchant. Contact technical.support@qfpay.com for clarification.

Supported Payment Types

Code	Description
800008	CPM for WeChat, Alipay, UnionPay QuickPass, PayMe
800101	Alipay MPM (Overseas Merchants)
800108	Alipay CPM (Overseas & HK Merchants)
801101	Alipay Web Payment (Overseas)
801107	Alipay WAP Payment (Overseas)
801110	Alipay In-App Payment (Overseas)
800107	Alipay Service Window H5 Payment
801501	Alipay MPM (HK Merchants)
801510	Alipay In-App (HK Merchants)
801512	Alipay WAP (HK Merchants)
801514	Alipay Web (HK Merchants)
800201	WeChat MPM (Overseas & HK)
800208	WeChat CPM (Overseas & HK)
800207	WeChat JSAPI Payment (Overseas & HK)
800212	WeChat H5 Payment
800210	WeChat In-App Payment (Overseas & HK)
800213	WeChat Mini-Program Payment
801008	WeChat Pay HK CPM (Direct Settlement, HK)
801010	WeChat Pay HK In-App (Direct Settlement, HK)
805801	PayMe MPM (HK Merchants)
805808	PayMe CPM (HK Merchants)
805814	PayMe Web Payment (HK Merchants)
805812	PayMe WAP Payment (HK Merchants)
800701	UnionPay QuickPass MPM
800708	UnionPay QuickPass CPM
800712	UnionPay WAP Payment (HK)
800714	UnionPay PC-Web Payment (HK)
802001	FPS MPM (HK Merchants)
803701	Octopus MPM (HK Merchants)
803712	Octopus WAP Payment (HK)
803714	Octopus PC-Web Payment (HK)
802801	Visa / Mastercard Online
802808	Visa / Mastercard Offline
806527	ApplePay Online
806708	UnionPay Card Offline
806808	American Express Card Offline

Special Remarks

• 801101: Transaction amount must be greater than 1 HKD
• 802001: This payment method does not support refunds

Supported Currencies

All codes follow ISO 4217 format (3-letter uppercase):

Code	Description
AED	Arab Emirates Dirham
CNY	Chinese Yuan
EUR	Euro
HKD	Hong Kong Dollar
IDR	Indonesian Rupiah
JPY	Japanese Yen
MMK	Myanmar Kyat
MYR	Malaysian Ringgit
SGD	Singapore Dollar
THB	Thai Baht
USD	United States Dollar
CAD	Canadian Dollar
AUD	Australian Dollar

Note: Some payment methods may only support HKD. Verify with your integration manager before non-HKD transactions.

Status Codes

Standard respcd values returned by QFPay API:

Code	Description
0000	Transaction successful
1100	System under maintenance
1101	Reversal error
1102	Duplicate request
1103	Request format error
1104	Request parameter error
1105	Device not activated
1106	Invalid device
1107	Device not allowed
1108	Signature error
1125	Transaction already refunded
1136	Transaction does not exist or not operational
1142	Order already closed
1143	Order not paid, password being entered
1145	Processing, please wait
1147	WeChat Pay transaction error
1150	T0 billing method does not support cancellation
1155	Refund request denied
1181	Order expired
1201	Insufficient balance
1202	Incorrect or expired payment code
1203	Merchant account error
1204	Bank error
1205	Transaction failed, try again later
1212	Please use UnionPay overseas payment code
1241	Store does not exist or status incorrect
1242	Store not configured correctly
1243	Store has been disabled
1250	Transaction forbidden
1251	Store configuration error
1252	System error making order request
1254	Problem occurred, resolving issue
1260	Order already paid
1261	Order not paid
1262	Order already refunded
1263	Order already cancelled
1264	Order already closed
1265	Transaction cannot be refunded (11:30pm-0:30am)
1266	Transaction amount wrong
1267	Order information mismatch
1268	Order does not exist
1269	Insufficient unsettled balance for refund
1270	Currency does not support partial refund
1271	Transaction does not support partial refund
1272	Refund amount exceeds maximum refundable
1294	Transaction non-compliant, prohibited by bank
1295	Connection slow, waiting for network response
1296	Connection slow, try again later
1297	Banking system busy
1298	Connection slow, do not repeat payment if already paid
2005	Customer payment code incorrect or expired
2011	Transaction serial number repeats

Usage Examples

Complete Payment Flow (Python)

import os
import requests
import hashlib
import datetime
import time

# Load configuration from environment variables
APPCODE = os.getenv('QFPAY_APPCODE')
KEY = os.getenv('QFPAY_KEY')
MCHID = os.getenv('QFPAY_MCHID')
ENV = os.getenv('QFPAY_ENV', 'test')

# Environment URLs
ENV_URLS = {
    'prod': 'https://openapi-hk.qfapi.com',
    'test': 'https://test-openapi-hk.qfapi.com',
    'sandbox': 'https://openapi-int.qfapi.com'
}

BASE_URL = ENV_URLS.get(ENV, ENV_URLS['test'])

def generate_signature(params, key, sign_type='SHA256'):
    """Generate signature for QFPay API request"""
    keys = list(params.keys())
    keys.sort()
    query = []
    for k in keys:
        if k not in ('sign', 'sign_type') and (params[k] or params[k] == 0):
            query.append(f'{k}={params[k]}')
    
    data = '&'.join(query) + key
    
    if sign_type == 'SHA256':
        sha256 = hashlib.sha256()
        sha256.update(data.encode('utf-8'))
        return sha256.hexdigest().upper()
    else:
        md5 = hashlib.md5()
        md5.update(data.encode('utf-8'))
        return md5.hexdigest().upper()

def create_payment(amount, currency, pay_type, goods_name, notify_url=None):
    """Create a payment request"""
    params = {
        'txamt': str(amount),
        'txcurrcd': currency,
        'pay_type': pay_type,
        'out_trade_no': f"ORDER{int(time.time() * 10000)}",
        'txdtm': datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
        'goods_name': goods_name
    }
    
    if MCHID:
        params['mchid'] = MCHID
    
    if notify_url:
        params['notify_url'] = notify_url
    
    signature = generate_signature(params, KEY)
    
    headers = {
        'X-QF-APPCODE': APPCODE,
        'X-QF-SIGN': signature,
        'Content-Type': 'application/x-www-form-urlencoded'
    }
    
    response = requests.post(
        f'{BASE_URL}/trade/v1/payment',
        data=params,
        headers=headers
    )
    
    return response.json()

def query_transaction(out_trade_no):
    """Query transaction status"""
    params = {
        'out_trade_no': out_trade_no,
        'txdtm': datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    }
    
    if MCHID:
        params['mchid'] = MCHID
    
    signature = generate_signature(params, KEY)
    
    headers = {
        'X-QF-APPCODE': APPCODE,
        'X-QF-SIGN': signature,
        'Content-Type': 'application/x-www-form-urlencoded'
    }
    
    response = requests.post(
        f'{BASE_URL}/trade/v1/query',
        data=params,
        headers=headers
    )
    
    return response.json()

def refund_transaction(out_trade_no, txamt, qf_trade_no=None):
    """Process a refund"""
    params = {
        'out_trade_no': out_trade_no,
        'txamt': str(txamt),
        'txdtm': datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    }
    
    if qf_trade_no:
        params['qf_trade_no'] = qf_trade_no
    
    if MCHID:
        params['mchid'] = MCHID
    
    signature = generate_signature(params, KEY)
    
    headers = {
        'X-QF-APPCODE': APPCODE,
        'X-QF-SIGN': signature,
        'Content-Type': 'application/x-www-form-urlencoded'
    }
    
    response = requests.post(
        f'{BASE_URL}/trade/v1/refund',
        data=params,
        headers=headers
    )
    
    return response.json()

# Example usage
if __name__ == '__main__':
    # Create a payment
    result = create_payment(
        amount=100,  # $1.00 HKD
        currency='HKD',
        pay_type='800101',
        goods_name='Test Product'
    )
    print(f"Payment created: {result}")
    
    if result.get('respcd') == '0000':
        out_trade_no = result['data']['out_trade_no']
        
        # Query transaction
        query_result = query_transaction(out_trade_no)
        print(f"Transaction status: {query_result}")

Environment Configuration with Multiple Merchants

import os

# Configuration loader from environment
class QFPayConfig:
    def __init__(self, env='sandbox'):
        self.env = env
        self.appcode = os.getenv(f'QFPAY_{env.upper()}_APPCODE') or os.getenv('QFPAY_APPCODE')
        self.key = os.getenv(f'QFPAY_{env.upper()}_KEY') or os.getenv('QFPAY_KEY')
        self.mchid = os.getenv(f'QFPAY_{env.upper()}_MCHID') or os.getenv('QFPAY_MCHID')
        
    @property
    def base_url(self):
        urls = {
            'prod': 'https://openapi-hk.qfapi.com',
            'test': 'https://test-openapi-hk.qfapi.com',
            'sandbox': 'https://openapi-int.qfapi.com'
        }
        return urls.get(self.env, urls['sandbox'])

# Usage
config = QFPayConfig(env=os.getenv('QFPAY_ENV', 'sandbox'))
print(f"Using base URL: {config.base_url}")

Important Notes

1. Signature Security: Never expose your client_key in frontend code or client-side applications. Always compute signatures on the server side.

2. Order Number Uniqueness: out_trade_no must be unique across all payment and refund requests under the same merchant account.

3. Character Encoding: All requests and responses use UTF-8 encoding.

4. Timeout Handling: For payment requests that don't return promptly, implement a polling mechanism to query transaction status.

5. Async Notifications: Configure notify_url to receive asynchronous payment completion notifications and verify notification signatures.

6. Refund Limitations: FPS (802001) payment type does not support refunds. Confirm business requirements before integration.

7. Amount Format: Amount is in cents. For example, 100 represents 1 HKD.

8. Timezone: The txdtm parameter uses the merchant's local timezone.

9. Environment Variables: Always load sensitive credentials from environment variables, never hardcode them in source files.

Technical Support

For any integration issues, contact:

• Email: technical.support@qfpay.com
• Documentation: https://sdk.qfapi.com
• Postman Collection: https://sdk.qfapi.com/assets/files/qfpay_openapi_payment_request.postman_collection-c8de8c8fe69f3fcd5a7653d41c289a29.json

See Also

• QFPay Developer Center
• Payment Integration Guides
• Checkout Integration