API Documentation

Authentication

All requests require your merchant_code and must be signed using MD5. Include the signature in the request body.

Signature generation:

1. Sort all non-empty parameters by key
2. Join as key=value&key2=value2&
3. Append key=YOUR_SECRET_KEY
4. MD5 hash → uppercase

Base URL

https://api.cowpay.co/v2/

All endpoints accept application/json and return JSON.

1. Create Payin Order

Initiate a deposit request. Returns a payment URL for the customer.

POST /payin

Request Parameters

Parameter	Type	Required	Description
merchant_code	String	Yes	Your merchant ID
country_code	String	Yes	Use `BD`
order_no	String	Yes	Unique order ID from your system
order_amount	String	Yes	Integer only (no decimals)
pay_type	String	Yes	See Pay Types below
notify_url	String	Yes	Webhook URL for result
return_url	String	No	Redirect after payment

Success Response

{
  "code": "0",
  "message": "success",
  "status": true,
  "order_no": "YOUR_ORDER_123",
  "plat_order_no": "D281335...",
  "pay_url": "https://payment.example.com/..."
}

Payin Pay Types

Type	Description
bkash	bKash agent account
nagad	Nagad agent account
bkash-native	bKash native account
bkash-merchant	bKash merchant account
bkash-send-money	bKash personal (Send Money)
nagad-send-money	Nagad personal (Send Money)

2. Check Payin Status

POST /payin/query

Required: merchant_code, country_code, order_no

Important: Always use the order_amount returned in the response as the final settled amount.

3. Payin Webhook

We send a POST request with JSON body when payment status changes. Reply with the plain string success.

{
  "sign": "169071F3858ECF55...",
  "transdata": {
    "code": 0,
    "order_no": "YOUR_ORDER_123",
    "order_status": "success",
    "order_amount": "1500.000000",
    "plat_order_no": "C25188...",
    "pay_type": "bkash-send-money"
  }
}

4. Create Payout Order

POST /withdraw

Parameter	Type	Required	Description
merchant_code	String	Yes	Your merchant ID
country_code	String	Yes	`BD`
order_no	String	Yes	Unique order ID
order_amount	String	Yes	Integer only
pay_type	String	Yes	`bkash` or `nagad`
bank_code	String	Yes	`bkash` or `nagad`
bank_card_no	String	Yes	11-digit phone (starts with 0)
bene_name	String	Yes	Payee full name
notify_url	String	Yes	Webhook URL

Important: If the payout request fails or times out, always verify the final status via the Query API before retrying. Never assume failure.

5. Check Payout Status

POST /withdraw/query

Required parameters: merchant_code, country_code, order_no, sign

6. Balance Query

POST /balance

{
  "code": 0,
  "message": "success",
  "status": true,
  "BD": {
    "balance": "10000",
    "canPayoutBalance": "8500",
    "payoutingAmount": "1000",
    "freezeAmount": "500",
    "currency": "BDT"
  }
}

Order Status Values

Payin

paying — Payment in progress
success — Payment successful
failed — Order failed

Payout

payouting — Payout in process
success — Payout successful
failed — Payout failed