Postman Integration

REPLACE EXAMPLE CREDENTIALS

The code examples below use placeholder credentials. You MUST replace them with your actual values from the merchant portal:

• PSTG6ELOB2YXKO4ZHRQ6NKTSBY → Your actual API Key
• MpkvVlXvYTZVPPJ0LReNA-g_yC7V7foe4UAj7tgWJSM → Your actual API Secret
• 1000 → Your actual Merchant ID (in the URL path)

Setup Steps

1. Create a new request in Postman
2. Set the request method and URL
3. Configure the request body (for POST requests)
4. Add a pre-request script to calculate the signature

Request Body Setup (Create Order)

Before adding the pre-request script, you need to configure the request body in Postman:

Step 1: Configure URL

Method: POSTURL: https://api.paystablecoin.global/api/v1/merchants/{merchantId}/orders

Replace {merchantId} with your actual Merchant ID (e.g., 1002)

Step 2: Configure Body

1. In Postman, click on the Body tab
2. Select raw format
3. Select JSON from the dropdown menu
4. Enter the following example:

{
  "merchantOrderId": "TEST_ORDER_{{$timestamp}}",
  "orderAmount": {
    "value": "99.99",
    "currency": "USD"
  },
  "expiresAt": "2025-12-31T23:59:59Z",
  "returnUrl": "https://yoursite.com/payment/success",
  "paymentMethod": {
    "supportedCurrencies": ["USDT", "USDC"],
    "preferredChain": "TRON"
  }
}

POSTMAN VARIABLES

You can use {{$timestamp}} in Postman to auto-generate unique order IDs. Postman will replace this with the current Unix timestamp.

REQUIRED FIELDS

The following fields are required for order creation:

• merchantOrderId - Your unique order ID
• orderAmount - Amount object with value and currency
• expiresAt - Order expiration time (UTC, ISO 8601 format)
• returnUrl - Customer redirect URL after payment

Optional fields:

• description - Order description
• callbackUrl - Server-to-server webhook URL
• customer - Customer information
• items - Line items
• metadata - Custom metadata

See API Reference for all available fields.

Step 3: Add Pre-request Script

Now that your request body is configured, add the pre-request script below to automatically calculate the signature.

Pre-request Script for POST Requests (Create Order)

// Configuration
const apiKey = 'PSTG6ELOB2YXKO4ZHRQ6NKTSBY';
const secretKey = 'MpkvVlXvYTZVPPJ0LReNA-g_yC7V7foe4UAj7tgWJSM';

// Generate timestamp (milliseconds)
const timestamp = Date.now().toString();

// Get request details
const method = pm.request.method;
const url = pm.request.url.toString();
const urlObj = new URL(url);
const path = urlObj.pathname;

// Get request body and replace Postman variables
let body = pm.request.body.raw;

// Replace {{$timestamp}} with actual value BEFORE signing
body = body.replace(/\{\{\$timestamp\}\}/g, timestamp);

// Minify JSON (remove extra spaces)
body = JSON.stringify(JSON.parse(body));

// Update the request body
pm.request.body.raw = body;

// Calculate request body hash (SHA256)
const bodyHash = CryptoJS.SHA256(body).toString(CryptoJS.enc.Base64);

// Build signature string
const signatureParts = [timestamp, method, path, bodyHash];
const stringToSign = signatureParts.join('\n');

console.log('=== Signature Calculation ===');
console.log('Timestamp:', timestamp);
console.log('Method:', method);
console.log('Path:', path);
console.log('Body Hash:', bodyHash);
console.log('String to Sign:', stringToSign.replace(/\n/g, ' | '));

// Calculate HMAC-SHA256 signature
const signature = CryptoJS.enc.Base64.stringify(CryptoJS.HmacSHA256(stringToSign, secretKey));

console.log('Signature:', signature);

// Set request headers
pm.request.headers.add({
	key: 'Content-Type',
	value: 'application/json'
});
pm.request.headers.add({
	key: 'X-Api-Key',
	value: apiKey
});
pm.request.headers.add({
	key: 'X-Timestamp',
	value: timestamp
});
pm.request.headers.add({
	key: 'X-Signature',
	value: signature
});

Query Order Setup

For querying orders, the setup is simpler since GET requests don't have a request body.

Step 1: Configure URL

Method: GETURL: https://api.paystablecoin.global/api/v1/merchants/{merchantId}/orders/{merchantOrderId}

Replace:

• {merchantId} with your Merchant ID (e.g., 1002)
• {merchantOrderId} with the order ID you want to query (e.g., TEST_ORDER_123)

Step 2: No Body Required

GET requests don't need a request body. Leave the Body tab empty or select none.

Step 3: Add Pre-request Script

Pre-request Script for GET Requests (Query Order)

// Configuration
const apiKey = 'PSTG6ELOB2YXKO4ZHRQ6NKTSBY';
const secretKey = 'MpkvVlXvYTZVPPJ0LReNA-g_yC7V7foe4UAj7tgWJSM';

// Generate timestamp (milliseconds)
const timestamp = Date.now().toString();

// Get request details
const method = pm.request.method;
const url = pm.request.url.toString();
const urlObj = new URL(url);
const path = urlObj.pathname;

// Build signature string (GET requests have no body)
const signatureParts = [timestamp, method, path];
const stringToSign = signatureParts.join('\n');

console.log('=== Signature Calculation ===');
console.log('Timestamp:', timestamp);
console.log('Method:', method);
console.log('Path:', path);
console.log('String to Sign:', stringToSign.replace(/\n/g, ' | '));

// Calculate HMAC-SHA256 signature
const signature = CryptoJS.enc.Base64.stringify(CryptoJS.HmacSHA256(stringToSign, secretKey));

console.log('Signature:', signature);

// Set request headers
pm.request.headers.add({
	key: 'X-Api-Key',
	value: apiKey
});
pm.request.headers.add({
	key: 'X-Timestamp',
	value: timestamp
});
pm.request.headers.add({
	key: 'X-Signature',
	value: signature
});

Complete Example: Create Your First Order

Follow these steps to create your first order using Postman:

1. Create New Request

1. Open Postman
2. Click New → HTTP Request
3. Name it "Create Order"

2. Configure Request

• Method: POST
• URL: https://api.paystablecoin.global/api/v1/merchants/1002/orders (Replace 1002 with your Merchant ID)

3. Add Request Body

1. Go to Body tab
2. Select raw and JSON
3. Paste this example:

{
  "merchantOrderId": "MY_ORDER_{{$timestamp}}",
  "orderAmount": {
    "value": "99.99",
    "currency": "USD"
  },
  "expiresAt": "2025-12-31T23:59:59Z",
  "returnUrl": "https://yoursite.com/payment/success",
  "paymentMethod": {
    "supportedCurrencies": ["USDT", "USDC"],
    "preferredChain": "TRON"
  }
}

4. Add Pre-request Script

1. Go to Pre-request Script tab
2. Paste the POST pre-request script from above
3. Update apiKey and secretKey with your actual credentials

5. Send Request

Click Send. You should receive a response like:

{
  "code": "00000",
  "message": "Success",
  "data": {
    "orderId": "20251202000100100000030000000139",
    "merchantId": "1002",
    "merchantOrderId": "MY_ORDER_1764662113279",
    "status": "INIT",
    "checkoutUrl": "https://checkout.paystablecoin.global/...",
    "createdAt": "2025-12-02T15:55:14Z",
    "expiresAt": "2025-12-31T23:59:59Z",
    "orderAmount": {
      "value": "99.99",
      "currency": "USD"
    }
  }
}

SUCCESS!

If you see "code": "00000" and "status": "INIT", your order was created successfully! You can use the checkoutUrl to complete the payment.

Troubleshooting

Common Errors

Error: "Invalid signature"

• Check that your apiKey and secretKey are correct
• Ensure the JSON body has no extra spaces (Postman should handle this automatically)
• Verify your system time is synchronized

Error: "Invalid or expired timestamp"

• Your computer clock may be out of sync
• Timestamp must be within ±5 minutes of server time

Error: "Missing required field: expiresAt"

• Make sure your request body includes all required fields
• Check for typos in field names

Error: "Invalid parameter: merchantId"

• Verify you're using the correct Merchant ID in the URL
• Check that the Merchant ID matches your credentials

Related Documentation

• Signature Algorithm - Learn signature calculation principles
• Important Notes - Check JSON format requirements