Wave Pay

Wave Pay (Pay with Wave API v1.3) sends the customer to Wave's payment page to pay with their WavePay wallet.

Call	What it does	Returns
wave.Initiate(ctx, &data)	Redirect to Wave's payment page	*RedirectPayment
wave.HandleCallback(request)	Verify the callback	*PaymentCallback

Wave Pay has no status API in this package: the callback is the only payment result.

Responses shows what Wave Pay puts in each result.

How it works

Wave sends the customer back to your return URL and posts the result to your callback URL separately.

Wave Pay: payment request, authenticate, result

Initiating a Payment

import (
	"fmt"
	"net/http"

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

wave, err := wavepay.New(wavepay.Config{
	MerchantID:        "...",
	SecretKey:         "...",
	MerchantName:      "My Shop",
	BaseURL:           wavepay.ProductionURL,
	BaseRedirectURL:   wavepay.ProductionURL,
	TimeToLiveSeconds: 300,
}, nil)
if err != nil {
	return err
}

data := wavepay.PaymentData{
	OrderID:     fmt.Sprintf("ORDER_%d", order.ID),
	CallbackURL: "https://shop.test/payments/wave/callback",
	ReturnURL:   fmt.Sprintf("https://shop.test/orders/%d", order.ID),
	Description: fmt.Sprintf("Order #%d", order.ID),
	Items: []wavepay.Item{
		{Name: "Product A", Amount: myanmarpayments.Kyat(6000)},
		{Name: "Product B", Amount: myanmarpayments.Kyat(4000)},
	},
}

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

// Store data.MerchantReferenceID with the order: Initiate filled it in.

http.Redirect(w, r, payment.URL, http.StatusFound)

Payments post as JSON, in MMK, to {BaseURL}/payment; the customer goes to {BaseRedirectURL}/authenticate?transaction_id=….

wavepay.PaymentData

Field	Type	Required	Rules
OrderID	string	Yes	Your order ID, at most 100 characters: letters, digits, _ and - only. One order can have several payment attempts
CallbackURL	string	Yes	Absolute http or https URL that Wave posts the result to, at most 255 characters
ReturnURL	string	Yes	Absolute http or https URL Wave sends the customer back to, at most 255 characters. Not proof of payment
Description	string	Yes	Shown to the customer, at most 255 characters
Items	[]wavepay.Item	Yes	At least one item
Amount	myanmarpayments.Amount	No	Whole kyat, greater than 0 (Wave doesn't accept decimals). Unset charges the sum of the items. Wave only accepts MMK
MerchantReferenceID	string	No	Unique ID of this attempt, at most 100 characters: letters, digits, _ and - only. Empty means a random ID
MerchantName	string	No	Business name shown on Wave's page for this payment. Empty uses Config.MerchantName; a name made only of whitespace is rejected
TimeToLiveSeconds	*int	No	Seconds the customer has to pay this payment, greater than 0, e.g. seconds := 600 then TimeToLiveSeconds: &seconds. nil uses Config.TimeToLiveSeconds; 0 is rejected
AdditionalField3, AdditionalField4, AdditionalField5	string	No	Extra information, at most 50 characters each, sent as additional_field_3–5 and echoed in the callback's additionalField3–5. Empty is not sent

Length limits count UTF-8 bytes. wavepay.Item has a Name and an Amount in whole kyat, greater than 0. The items are summed with exact integer arithmetic, never floats; data.ResolvedAmount() returns the total that will be charged.

Per-Payment Merchant Name and Time to Live

MerchantName and TimeToLiveSeconds override the wavepay.Config values for one payment, including in the request hash.

seconds := 600
data := wavepay.PaymentData{
	OrderID:           fmt.Sprintf("ORDER_%d", order.ID),
	CallbackURL:       "https://shop.test/payments/wave/callback",
	ReturnURL:         fmt.Sprintf("https://shop.test/orders/%d", order.ID),
	Description:       fmt.Sprintf("Order #%d", order.ID),
	Items:             []wavepay.Item{{Name: "Concert ticket", Amount: myanmarpayments.Kyat(25000)}},
	MerchantName:      "My Shop Events",
	TimeToLiveSeconds: &seconds,
}

Merchant Reference ID

Wave rejects a reused merchant_reference_id (409 Record already exists), so every attempt, including a retry of the same order, needs a new one. Leave it empty to get a fresh random ID, and store it: Wave marks orderId as optional in callbacks, while merchantReferenceId is always present. Initiate takes a pointer and writes the generated ID to data.MerchantReferenceID once data passes validation.

Handling Callbacks

import (
	"net/http"

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

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

if callback.IsSuccessful() {
	// callback.OrderID is your OrderID
	// callback.Raw["merchantReferenceId"] is the attempt's reference
	// callback.GatewayReference is Wave's transactionId
}

callback.Acknowledgement.Write(w)

callback.OrderID falls back to merchantReferenceId when Wave's orderId is missing, null or empty.

Wave hashes the values joined with no separator, so a matching hashValue alone doesn't pin down where one value ends and the next begins. After the hash matches, amount must be a decimal (e.g. 10000 or 10000.00), at least one of orderId and merchantReferenceId must be present, and each one sent may only hold letters, digits, _ and -; otherwise HandleCallback returns *myanmarpayments.SignatureVerificationError. New payments are held to the same ID rules, so every callback for a payment made with this package passes them.

Responses

What Wave Pay puts in each field. See Results and PaymentCallback & Status for the full structs.

Initiate() → *myanmarpayments.RedirectPayment

Field / Method	Wave Pay value
Flow()	FlowRedirect
OrderID	Your data.OrderID
URL	{BaseRedirectURL}/authenticate?transaction_id=… (URL-encoded), e.g. https://payments.wavemoney.io/authenticate?transaction_id=…
GatewayReference	Wave transaction_id. Always set
Raw	Wave's /payment response: message (success), transaction_id

The attempt's MerchantReferenceID is not on the result: read it from data.MerchantReferenceID.

HandleCallback() → *myanmarpayments.PaymentCallback

Field	Wave Pay value
OrderID	Wave orderId, falling back to merchantReferenceId when it is missing, null or empty
Status	status mapped, see Statuses
GatewayStatus	Wave status, trimmed, e.g. PAYMENT_CONFIRMED
GatewayReference	Wave transactionId
Amount	Wave amount, e.g. 10000
Raw	The verified body: status, merchantId, orderId, merchantReferenceId, frontendResultUrl, backendResultUrl, initiatorMsisdn, amount, timeToLiveSeconds, paymentDescription, currency, additionalField1–5, transactionId, paymentRequestId, requestTime, hashValue
Acknowledgement	HTTP 200, empty body, Content-Type: text/plain

Statuses

Only PAYMENT_CONFIRMED means the customer paid.

Wave status	PaymentStatus
PAYMENT_CONFIRMED	StatusSuccessful
BILL_COLLECTION_FAILED, INSUFFICIENT_BALANCE, ACCOUNT_LOCKED	StatusFailed
PAYMENT_REQUEST_CANCELLED	StatusCanceled
TRANSACTION_TIMED_OUT, SCHEDULER_TRANSACTION_TIMED_OUT	StatusExpired
anything else	StatusUnknown

SCHEDULER_TRANSACTION_TIMED_OUT arrives up to 15 minutes after the time-to-live ends.

Errors

Call	Returns	When
Initiate()	*InvalidPaymentDataError	data.Validate() fails. Nothing is sent and data is left untouched. Item errors use items.0.amount keys
Initiate()	*APIError	Wave answers with an HTTP error, a message other than success, or no transaction_id
HandleCallback()	*SignatureVerificationError	hashValue doesn't match, a hashed field holds an object or array, amount isn't a decimal, both orderId and merchantReferenceId are empty, or either holds anything but letters, digits, _ and -

HTTPStatus tells Wave's rejections apart: 400 invalid hash, 404 unknown merchant, 409 reused reference, 422 validation (GatewayCode is VALIDATION_ERROR).