Payment signature and sign errors

This page helps verify payment link signature generation and quickly troubleshoot error sign.

Signature algorithm

1. Take parameters: shop_id, amount, currency, order_id.
2. If you send test=1, include test in signature input too.
3. Sort keys (same as PHP ksort).
4. Build query string like PHP http_build_query.
5. Calculate: md5(query + SECRET).

PHP reference example

<?php
$secret = 'YOUR_SECRET';
$data = [
    'shop_id' => 'SHOP_HASH',
    'amount' => '3000',
    'currency' => 'RUB',
    'order_id' => 'ef4c6d4e-660b-4ec8-b32a-31ea523ee758',
    // 'test' => '1', // only if you really send test=1
];
ksort($data);
$query = http_build_query($data);
$sign = md5($query . $secret);
?>

Python example (server-compatible)

import hashlib
from urllib.parse import urlencode

def make_sign(params: dict, secret: str) -> str:
    sorted_params = dict(sorted(params.items(), key=lambda x: x[0]))
    query = urlencode(sorted_params)  # compatible for standard scalar values
    return hashlib.md5((query + secret).encode("utf-8")).hexdigest()

Common reasons for error sign

• amount was signed as 3000 but sent as 3000.0 (or vice versa).
• test was included in signature but not sent in request (or vice versa).
• Wrong secret or wrong shop ID is used.
• Different key order is used during signing.
• Unexpected fields are included in signature input.

Production diagnostics

The admin orders page includes a signature diagnostics panel now. You can filter by shop_id and inspect recent sign-related failures.

Main payment creation docs: /docs/en/payments/create-payment/.