SDKs

QPay provides official SDKs for 11 languages, plus a cURL reference collection. Each SDK is a standalone package with identical functionality, covering all QPay V2 API endpoints.

Common Features

Every SDK includes:

Automatic token management — Access tokens are obtained, cached, and refreshed transparently. You never need to call auth endpoints manually.
Type-safe models — Strongly typed request and response objects in every language.
Structured error handling — Dedicated error types with HTTP status codes, QPay error codes, messages, and raw response bodies.
Full API coverage — Invoices (create, simple, ebarimt, cancel), payments (get, check, list, cancel, refund), and ebarimt operations (create, cancel).
Environment variable support — Load configuration from QPAY_* environment variables with a single function call.
Custom HTTP client support — Bring your own HTTP client for timeouts, proxies, or testing.

Available SDKs

Language	Package	Registry	Install Command
Go	`qpay-go`	pkg.go.dev	`go get github.com/qpay-sdk/qpay-go`
JavaScript / TypeScript	`qpay-js`	npm	`npm install qpay-js`
Python	`qpay-py`	PyPI	`pip install qpay-py`
PHP	`usukhbayar/qpay-php`	Packagist	`composer require usukhbayar/qpay-php`
Java	`qpay-java`	Maven Central	Maven / Gradle
Ruby	`qpay-sdk`	RubyGems	`gem install qpay-sdk`
.NET (C#)	`QPay`	NuGet	`dotnet add package QPay`
Dart / Flutter	`qpay`	pub.dev	`dart pub add qpay`
Swift	`QPay`	SPM	Swift Package Manager
Rust	`qpay`	crates.io	`cargo add qpay`
cURL	`qpay-curl`	GitHub	Shell scripts (no install)

Environment Variables

All SDKs read the same set of environment variables:

Variable	Required	Description
`QPAY_BASE_URL`	Yes	QPay API base URL (e.g., `https://merchant.qpay.mn`)
`QPAY_USERNAME`	Yes	QPay merchant username
`QPAY_PASSWORD`	Yes	QPay merchant password
`QPAY_INVOICE_CODE`	Yes	Default invoice code for your merchant
`QPAY_CALLBACK_URL`	Yes	URL that QPay calls after a payment is completed

API Coverage

All SDKs implement every operation in the QPay V2 API:

Operation	Method	Endpoint	Description
Get Token	POST	`/v2/auth/token`	Authenticate with Basic Auth and get access/refresh tokens
Refresh Token	POST	`/v2/auth/refresh`	Refresh an expired access token using the refresh token
Create Invoice	POST	`/v2/invoice`	Create a detailed invoice with all available options
Create Simple Invoice	POST	`/v2/invoice`	Create an invoice with minimal required fields
Create Ebarimt Invoice	POST	`/v2/invoice`	Create an invoice with tax (ebarimt) information
Cancel Invoice	DELETE	`/v2/invoice/{id}`	Cancel an existing unpaid invoice
Get Payment	GET	`/v2/payment/{id}`	Retrieve full payment details by payment ID
Check Payment	POST	`/v2/payment/check`	Check if a payment has been made for an invoice
List Payments	POST	`/v2/payment/list`	List payments with date range and pagination
Cancel Payment	DELETE	`/v2/payment/cancel/{id}`	Cancel a card payment
Refund Payment	DELETE	`/v2/payment/refund/{id}`	Refund a card payment
Create Ebarimt	POST	`/v2/ebarimt_v3/create`	Create an electronic tax receipt for a payment
Cancel Ebarimt	DELETE	`/v2/ebarimt_v3/{id}`	Cancel an electronic tax receipt

Typical Integration Flow

Create an invoice — Call createSimpleInvoice with an amount and description. You get back a QR image and bank app deep links.
Display to the user — Show the QR code or open a bank app deep link on mobile.
Poll for payment — Periodically call checkPayment with the invoice ID to see if payment has been received.
Receive callback — QPay sends a POST request to your callback_url when payment completes.
Issue ebarimt — Optionally call createEbarimt to generate an electronic tax receipt.

GitHub Organization

All SDK repositories are hosted under the qpay-sdk GitHub organization.