click-integration

Click Payment Integration — Expert Guide

This skill makes you a super-expert on Click payment system integration in Uzbekistan. Every page from docs.click.uz is captured in the reference files below — nothing is cut or summarized.

Quick Reference

Item	Value
Payment page URL	https://my.click.uz/services/pay
Merchant API endpoint	https://api.click.uz/v2/merchant/
Merchant cabinet	https://merchant.click.uz
Documentation	https://docs.click.uz
SHOP API Protocol	HTTP/HTTPS POST, application/x-www-form-urlencoded
Merchant API Protocol	HTTPS, application/json (also supports application/xml)
Currency	UZS, amounts in so'm (NOT tiyin — unlike Payme!)
Amount format	float with 2 decimal places (e.g., 1000.00)
SHOP API auth	MD5 sign_string hash
Merchant API auth	SHA1 digest in Auth header
Checkout.js CDN	https://my.click.uz/pay/checkout.js
Android SDK	https://github.com/click-llc/android-msdk

Choosing the Right Integration Method

Click offers multiple ways to accept payments. Read the appropriate reference file for full details.

1. SHOP API — "Click calls YOUR server" (most common)

• User pays via Click → Click sends Prepare/Complete to your server
• You implement 1 callback endpoint handling 2 actions
• Read: references/02-shop-api-requests.md

2. Payment Button/Link — "Redirect user to Click"

• Simple link/form redirects user to my.click.uz payment page
• Works with SHOP API callback on your server
• Read: references/05-payment-button.md

3. Inline Checkout — "Pay on YOUR site without redirect"

• Embed checkout.js widget — payment form opens as overlay
• No redirect to my.click.uz needed
• Read: references/06-inline-checkout.md

4. Merchant API — "YOU call Click's server"

• Create invoices, check payment status, refund, card tokens
• Supplements SHOP API, not a replacement
• Read: references/08-merchant-api-requests.md

5. CLICK Pass — "QR-code POS payment"

• Merchant scans QR from user's Click app
• For physical retail, kiosks
• Read: references/10-click-pass.md

6. Telegram Bot Payments

• Accept payments inside Telegram via Click provider
• Uses Telegram Bot API with Click provider_token
• Read: references/12-telegram-payments.md

7. Mobile SDK / Deep Links

• Android SDK library or deep link integration (Android + iOS)
• Read: references/13-mobile-sdk.md

Decision Matrix

Method	Who initiates	Where user pays	Best for
SHOP API + Payment Button	User clicks link	Click web/app	E-commerce, web
SHOP API + Inline Checkout	User on your site	Overlay on your site	SPA, custom UX
Merchant API Invoice	Merchant sends invoice	User confirms in Click app	Subscriptions, push billing
Merchant API Card Token	Merchant charges token	No user interaction	Recurring, card-on-file
CLICK Pass	Merchant scans QR	Already in Click app	Physical retail, POS
Telegram Payments	User in Telegram	Telegram payment UI	Telegram bots
Mobile SDK / Deep Link	User in your app	Click app or browser	Mobile apps

Sign String Formulas (SHOP API)

Request	Formula
Prepare (action=0)	MD5(click_trans_id + service_id + SECRET_KEY + merchant_trans_id + amount + action + sign_time)
Complete (action=1)	MD5(click_trans_id + service_id + SECRET_KEY + merchant_trans_id + merchant_prepare_id + amount + action + sign_time)

CRITICAL: Parameters concatenated WITHOUT separators. Use constant-time comparison (e.g., crypto.timingSafeEqual).

Merchant API Authentication

Auth: {merchant_user_id}:{digest}:{timestamp}

• digest = SHA1(timestamp + secret_key)
• timestamp = UNIX timestamp (10-digit seconds)

Error Codes Summary (SHOP API)

error	error_note	Description
0	Success	OK
-1	SIGN CHECK FAILED!	Signature verification failed
-2	Incorrect parameter amount	Wrong amount
-3	Action not found	Unknown action
-4	Already paid	Duplicate payment
-5	User does not exist	Order/user not found
-6	Transaction does not exist	Payment record not found
-7	Failed to update user	DB/balance update error
-8	Error in request from click	Malformed request
-9	Transaction cancelled	Previously cancelled

Merchant API HTTP Error Codes

Code	Description
200, 201	OK
400	Bad request (malformed data or URI)
401	Not authorized (auth error)
403	Forbidden (method not allowed)
404	Not found (method not found)
406	Not acceptable (invalid data type)
410	Gone (deprecated method)
500	Internal server error
502	Service is down or being upgraded

Before You Start — Setup Checklist

1. Register with Click and sign contract with connected bank
2. Receive credentials: merchant_id, service_id, SECRET_KEY, merchant_user_id
3. Get access to merchant cabinet at merchant.click.uz
4. Set Prepare URL and Complete URL in merchant cabinet → Сервисы → pencil icon
5. Request service activation from Click support (disabled by default!)
6. If NOT on TAS-IX: provide domain + IP + port for firewall whitelisting
7. Static IP required — notify Click before changing

Critical Implementation Rules

1. Single callback endpoint — one URL for both Prepare (action=0) and Complete (action=1)
2. Content-Type is form-urlencoded — SHOP API sends application/x-www-form-urlencoded, NOT JSON
3. Amounts in SO'M — NOT tiyin! Float format: 50000.00
4. Always verify sign_string with constant-time comparison
5. Check error field in requests — if Click sends error ≤ -1, respond with error -9
6. Protect against duplicate click_trans_id processing
7. Verify merchant_prepare_id in Complete matches Prepare record
8. Complete error=0 → fulfill order; error<0 → cancel order
9. Fiscalization mandatory for more than 1 IKPU code
10. Service must be activated by Click support before real payments
11. IP must be static — notify Click before any change
12. Log click_paydoc_id — shown in user's SMS, needed for support queries

Common Gotchas

• Callback URLs must be publicly accessible — localhost won't work in production
• Prepare URL validation — merchant cabinet validates format; must be valid HTTPS URL
• sign_string concatenation — NO separators between params
• merchant_prepare_id overflow — use proper integer, Date.now() % 2147483647 causes collisions
• Response must always be JSON with all required fields, even on error
• After successful Complete (error=0) — response CANNOT be error (except -4 or -9)
• If fulfillment fails after successful Complete — respond success, then cancel via Merchant API reversal

Reference Files — Complete docs.click.uz Mirror

Each file corresponds 1:1 to a docs.click.uz page. Nothing is cut.

SHOP API

• references/01-shop-api-overview.md — General provisions, terms, flow diagram
• references/02-shop-api-requests.md — Prepare & Complete full spec with code examples
• references/03-shop-api-errors.md — All error codes (Click-side and merchant-side)
• references/04-shop-api-testing.md — Testing software, scenarios, report generation

Payment Integration

• references/05-payment-button.md — Payment link URL and HTML form (with redirect)
• references/06-inline-checkout.md — checkout.js widget, createPaymentRequest() JS API

Merchant API

• references/07-merchant-api-overview.md — General provisions, terms, flow diagram, contract info
• references/08-merchant-api-requests.md — All endpoints: invoice, payment status, reversal, card token
• references/09-merchant-api-errors.md — HTTP status codes

Additional

• references/10-click-pass.md — QR-code POS payments, confirm mode
• references/11-fiscalization.md — OFD submit_items, submit_qrcode, get fiscal data
• references/12-telegram-payments.md — Bot setup, sendInvoice, pre_checkout_query, live mode
• references/13-mobile-sdk.md — Android SDK, iOS deep links, return_url handling
• references/14-server-examples.md — Official PHP, Django repos + community Node.js/TypeScript
• references/15-cms-plugins.md — WooCommerce, OpenCart, Drupal, 1C-Bitrix, Joomla, CS-Cart