Yoma MMQR

Yoma MMQR is Yoma Bank's MMQR gateway: it issues ready-made QR images that customers scan with any MMQR wallet.

Call	What it does	Returns
`yoma.Initiate(ctx, data)`	Check out the order and generate its first QR	`*QrPayment`
`yoma.RenewQR(ctx, orderID)`	Generate a new QR for a checked-out order	`*QrPayment`
`yoma.Status(ctx, reference)`	Check a QR's payment status	`*PaymentStatusResult`
`yoma.HandleCallback(request)`	Verify the callback	`*PaymentCallback`

Responses shows what Yoma MMQR puts in each result.

How it works

Yoma checks each order out once, then issues QR codes that each stay payable for 120 seconds.

Yoma MMQR: token, checkout, QR, renewal, result

Initiating a Payment

import (
	"fmt"

	myanmarpayments "github.com/laranex/go-myanmar-payments/v4"
	"github.com/laranex/go-myanmar-payments/v4/yomammqr"
)

yoma, err := yomammqr.New(
	yomammqr.Config{
		MerchantID:     "...",
		ClientID:       "...",
		ClientSecret:   "...",
		WebhookHashKey: "...",
		APIVersion:     "v1rc",
		TimeoutSeconds: 30,
	},
	nil, // default HTTP client
	nil, // in-memory token cache; share this gateway across requests
)
if err != nil {
	return err
}

data := yomammqr.PaymentData{
	OrderID:     fmt.Sprintf("ORDER_%d", order.ID),
	Amount:      myanmarpayments.Kyat(10000),
	Description: fmt.Sprintf("Order #%d", order.ID),
}

payment, err := yoma.Initiate(ctx, data)
if err != nil {
	return err
}

// Store payment.Reference with the order for status checks.

src := payment.QRImageDataURI("")
fmt.Fprintf(w, `<img src="%s" alt="Scan with any MMQR wallet">`, src)

yomammqr.PaymentData

Field	Type	Required	Rules
`OrderID`	`string`	Yes	Unique order number, at most 20 characters
`Amount`	`myanmarpayments.Amount`	Yes	Whole kyat, greater than 0, e.g. `Kyat(10000)`. Yoma documents no decimals or currency
`Description`	`string`	Yes	At most 50 characters

QR Image

QRImage is an already rendered base64 PNG of the payment slip: display it as is, no QR library needed.

Handling Callbacks

import (
	"net/http"

	myanmarpayments "github.com/laranex/go-myanmar-payments/v4"
)

// POST /payments/yoma/callback
request, err := myanmarpayments.NewCallbackRequestFromHTTP(r)
if err != nil {
	http.Error(w, "invalid callback", http.StatusBadRequest)
	return
}
callback, err := yoma.HandleCallback(request)
if err != nil {
	http.Error(w, "invalid callback", http.StatusBadRequest)
	return
}

if callback.IsSuccessful() {
	// callback.OrderID is your orderNumber
}

callback.Acknowledgement.Write(w)

The callback URL is registered with Yoma, not sent per order. When WebhookSecret is configured, callbacks must carry it in the X-Webhook-Secret header. The hash is checked with HMAC-SHA256 keyed with your order number plus WebhookHashKey.

QR Lifetime and Renewal

A QR is payable for 120 seconds (yomammqr.QRLifetime); payment.ExpiresAt tells you when. Yoma accepts each order number once, so never call Initiate again for the same order. Renew the QR instead:

import "fmt"

payment, err := yoma.RenewQR(ctx, fmt.Sprintf("ORDER_%d", order.ID))
if err != nil {
	return err
}

// Store the new payment.Reference: the previous one stops working.

Each renewal retires the previous Reference; only the newest one answers status checks.

Status Checks

// reference is the payment.Reference you stored
result, err := yoma.Status(ctx, reference)
if err != nil {
	return err
}

if result.IsSuccessful() {
	// the QR was paid
}

Status takes the QR's Reference, not your OrderID. An expired QR returns StatusExpired instead of an error.

Responses

What Yoma MMQR puts in each field. See Results and PaymentCallback & Status for the full structs. On error the result is nil. A field the gateway didn't send is "". Raw holds plain Go values (JSON numbers become json.Numbers).

`Initiate()` → `*myanmarpayments.QrPayment`

Field / Method	Yoma MMQR value
`Flow()`	`FlowQR`
`OrderID`	Your `data.OrderID` (Yoma `orderNumber`)
`QRString`	Always `""`
`QRImage`	Yoma `qrString`, a base64 PNG of the payment slip. Always set
`ExpiresAt`	Now + 120 seconds (`yomammqr.QRLifetime`). Always set
`Reference`	Yoma `refLabel`, e.g. `100000083331`. Pass it to `Status`. Always set
`Raw`	The `qr/generate` response: `refLabel`, `qrString`, `errorCode` (`nil`), `errorDescription`
`QRImageDataURI("")`	`data:image/png;base64,…`

Initiate checks the order out (payment/checkout), then generates its first QR; the result comes from the generate call.

`RenewQR()` → `*myanmarpayments.QrPayment`

The same values as Initiate() for the orderID you passed, with a new QRImage, Reference and ExpiresAt. The previous Reference stops answering status checks.

`Status()` → `*myanmarpayments.PaymentStatusResult`

Field	Yoma MMQR value
`OrderID`	Always `""`: Yoma only returns the reference
`Status`	`paymentStatus` mapped case-insensitively, see Statuses. `StatusExpired` for a `QR EXPIRED` error
`GatewayStatus`	Yoma `paymentStatus`, trimmed, e.g. `SUCCESS`. `QR EXPIRED` for an expired QR
`GatewayReference`	Yoma `refLabel`, falling back to the reference you passed. Always set
`Amount`	Always `""`: Yoma's status response has no amount
`Raw`	The `payment/check-status` response: `refLabel`, `paymentStatus`, `errorCode`, `errorDescription`

`HandleCallback()` → `*myanmarpayments.PaymentCallback`

Field	Yoma MMQR value
`OrderID`	Yoma `orderNumber` (your `OrderID`)
`Status`	`status` mapped case-insensitively, see Statuses
`GatewayStatus`	Yoma `status`, trimmed, as sent, e.g. `success`
`GatewayReference`	Always `""`: Yoma's callback has no reference
`Amount`	Always `""`: Yoma's callback has no amount
`Raw`	The verified body: `orderNumber`, `status`, `hashValue`
`Acknowledgement`	HTTP `200`, empty body, `Content-Type: text/plain`

Statuses

Yoma value	`PaymentStatus`
`success` (callback), `SUCCESS` (status)	`StatusSuccessful`
`PENDING`	`StatusPending`
`fail` (callback), `FAILED` (status)	`StatusFailed`
`QR EXPIRED` error	`StatusExpired`
anything else	`StatusUnknown`

Access Tokens

Yoma authenticates with an OAuth token that lasts hours. The gateway keeps it in the token cache, shares one token request between concurrent calls, and fetches a new token, retrying once, when Yoma answers 401. The shared token request runs without any one call's cancellation and is bounded by the HTTP client timeout, so canceling one call's ctx never fails the others; that call stops waiting and returns an *APIError. yoma.ForgetToken() drops the cached token, e.g. after rotating the client secret.

The token is cached under myanmar-payments.yoma-mmqr.token.<sha256(baseURL|clientID)>, the same key every Laranex SDK uses, so services in different languages can share one cache, for Yoma's expires_in minus 60 seconds (at least 60 seconds). expires_in is read from its leading digits, so 28800.0 is 28800 seconds; a missing or non-positive value means 3600.

Errors

Call	Returns	When
`Initiate()`	`*InvalidPaymentDataError`	`data.Validate()` fails. Nothing is sent
`Initiate()`	`*APIError`	The token request fails, Yoma answers with an HTTP error or an `errorCode` (e.g. `PAYMENT ALREADY EXISTS`), `checkOutStatus` isn't `true`, or there is no `qrString` or `refLabel`
`RenewQR()`	`*APIError`	As `Initiate()`, without the checkout
`Status()`	`*APIError`	The token request fails, or Yoma answers with an HTTP error or any `errorCode` other than `QR EXPIRED`
`HandleCallback()`	`*SignatureVerificationError`	`X-Webhook-Secret` is missing or wrong (when `WebhookSecret` is set), `orderNumber` is missing, `status` holds an object or array, or `hashValue` doesn't match

The error types live in the root myanmarpayments package. Yoma reports business errors with HTTP 200 and an errorCode; *APIError carries it in GatewayCode and Yoma's errorDescription in GatewayMessage. When Yoma can't be reached or ctx is canceled, the calls return *APIError, which unwraps to the cause (errors.Is(err, context.DeadlineExceeded)).

Yoma MMQR ​

How it works ​

Initiating a Payment ​

yomammqr.PaymentData ​

QR Image ​

Handling Callbacks ​

QR Lifetime and Renewal ​

Status Checks ​

Responses ​

Initiate() → *myanmarpayments.QrPayment ​

RenewQR() → *myanmarpayments.QrPayment ​

Status() → *myanmarpayments.PaymentStatusResult ​

HandleCallback() → *myanmarpayments.PaymentCallback ​

Statuses ​

Access Tokens ​

Errors ​