PayU India Python Integration

Warnings

• breaking 'payu' on PyPI is an HPC workflow scheduling tool — completely unrelated to PayU India payments. 'pip install payu' installs the wrong thing.
  Fix: Use payu_websdk (install from GitHub) or implement hash generation manually with requests.
• breaking Hash formula requires exactly 6 pipe characters between udf5 and salt: key|txnid|amount|productinfo|firstname|email|udf1|udf2|udf3|udf4|udf5||||||salt. Wrong pipe count causes PayU to reject the transaction with 'hash mismatch' error.
  Fix: Count pipes: after udf5 there are 6 consecutive pipes before salt. Use f-string: f'...{udf5}||||||{salt}'
• breaking Amount must be a string with 2 decimal places — not an integer or float. '500.00' not 500 or 500.0. Wrong type causes hash mismatch.
  Fix: amount = f'{float_amount:.2f}' — always format to 2 decimal places as string.
• breaking Hash must be lowercase. SHA512 output must be converted with .lower(). Uppercase hash causes payment failure.
  Fix: hashlib.sha512(hash_str.encode()).hexdigest().lower()
• gotcha Reverse hash verification mandatory after payment. PayU returns hash in reverse order: sha512(SALT|status||||||udf5|udf4|udf3|udf2|udf1|email|firstname|productinfo|amount|txnid|key). Must verify this on your server.
  Fix: Implement reverse hash: salt|status||||||udf5|udf4|...|key and compare with hash returned in PayU callback.
• gotcha Test environment: test.payu.in. Production: secure.payu.in. Using production URL with test keys or vice versa causes connection failure.
  Fix: TEST: POST to https://test.payu.in/_payment. LIVE: POST to https://secure.payu.in/_payment.
• gotcha txnid must be unique for every transaction — max 25 chars, alphanumeric. Duplicate txnid causes 'duplicate transaction' error.
  Fix: Use UUID: import uuid; txnid = str(uuid.uuid4()).replace('-', '')[:25]

Install

• pip install git+https://github.com/payu-india/web-sdk-python.git Python (official PayU web SDK — GitHub only, not on PyPI)

Imports

• Hash generation (manual — recommended approach)

  import hashlib
  
  def generate_payu_hash(key, txnid, amount, productinfo,
                        firstname, email, salt,
                        udf1='', udf2='', udf3='', udf4='', udf5=''):
      """
      PayU hash formula:
      sha512(key|txnid|amount|productinfo|firstname|email|
             udf1|udf2|udf3|udf4|udf5||||||salt)
      Amount must be a string. Hash must be lowercase.
      """
      hash_str = (
          f'{key}|{txnid}|{amount}|{productinfo}|{firstname}|{email}|'
          f'{udf1}|{udf2}|{udf3}|{udf4}|{udf5}||||||{salt}'
      )
      return hashlib.sha512(hash_str.encode('utf-8')).hexdigest().lower()
  
  # Usage
  hash_val = generate_payu_hash(
      key='your_key',
      txnid='unique_txn_001',
      amount='500.00',   # string, in rupees
      productinfo='Widget',
      firstname='John',
      email='john@example.com',
      salt='your_salt'
  )
  print(hash_val)

  Hash must include udf1-udf5 fields (even if empty) followed by exactly 6 pipe characters before salt. Wrong pipe count causes hash mismatch and payment failure.
• payu_websdk Client

  import payu_websdk
  
  # ENV: 'TEST' or 'LIVE'
  client = payu_websdk.Client('YOUR_KEY', 'YOUR_SALT', 'TEST')
  
  # Verify payment status
  result = client.verify_payment('txnid_001')
  print(result)
  
  # Refund
  refund = client.refund_transaction(
      mihpayid='payu_transaction_id',
      token='unique_refund_token',
      amount='100.00'
  )
  print(refund)

  'import payu' imports an HPC scheduling tool, not PayU payments. payu_websdk is the correct import for PayU India SDK.

Quickstart

PayU India — manual hash generation and payment form data preparation.

import hashlib
import requests
import uuid

# PayU credentials from dashboard.payu.in
KEY = 'your_merchant_key'
SALT = 'your_merchant_salt'
ENV = 'test'  # 'test' or 'prod'

BASE_URL = 'https://test.payu.in' if ENV == 'test' else 'https://secure.payu.in'

def generate_hash(key, txnid, amount, productinfo, firstname, email, salt, **udf):
    udf1 = udf.get('udf1', '')
    udf2 = udf.get('udf2', '')
    udf3 = udf.get('udf3', '')
    udf4 = udf.get('udf4', '')
    udf5 = udf.get('udf5', '')
    hash_str = f'{key}|{txnid}|{amount}|{productinfo}|{firstname}|{email}|{udf1}|{udf2}|{udf3}|{udf4}|{udf5}||||||{salt}'
    return hashlib.sha512(hash_str.encode()).hexdigest().lower()

# Create payment params
txnid = str(uuid.uuid4())[:20]
amount = '500.00'  # string, rupees

hash_val = generate_hash(
    KEY, txnid, amount,
    'Widget', 'John', 'john@example.com',
    SALT
)

payment_data = {
    'key': KEY,
    'txnid': txnid,
    'amount': amount,
    'productinfo': 'Widget',
    'firstname': 'John',
    'email': 'john@example.com',
    'phone': '9999999999',
    'surl': 'https://yourapp.com/payment/success',  # success URL
    'furl': 'https://yourapp.com/payment/failure',  # failure URL
    'hash': hash_val,
}
# POST this form data to BASE_URL/_payment
print('POST to:', f'{BASE_URL}/_payment')
print('Params:', payment_data)