Product Site | Payment Gateway | Demo Exchange | Bureau de Change
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API Installation Manual



LimitlexPAY allows users to interact with payment gateway platform programmatically via HTTP API (view, add and cancel payments as well as check if payment was successful). Service URL:


Webhook / Instant Payment Notification (IPN)

Webhook Notifications URL can be set to notify when payments status changes.

Performing a call

API calls are generated with URL, followed by endpoint URL and request data. Each API call requires:

  • pos_id

For localization you can use locale parameter:

  • locale


API calls are authenticated using HTTP Basic access authentication. You can generate your API key in your Account.

Error handling

On error there will be err element in result. Err value contains error description.

API reference

API calls are performed by sending a HTTP request to URL starting with link, followed by endpoint URL and request data.

GET/GetRate/?pos_id={pos_id}&invoice_currency={invoice_currency}&invoice_amount={invoice_amount}&currency= {currency}&accept_zero_confirmations={accept_zero_confirmations}returns {invoice_amount, invoice_currency, currency, rate, amount_exchange, network_processing_fee, amount, fast_transaction_fee, fast_transaction_fee_currency, wait_time}
GET /StartPayment/?pos_id={pos_id}&invoice_currency={invoice_currency}&invoice_amount={invoice_amount}&currency={currency}&reference_no={reference_no} &accept_zero_confirmations={accept_zero_confirmations}returns {payment_id, invoice_amount, invoice_currency, currency, rate, amount_exchange, network_processing_fee, amount, fast_transaction_fee, fast_transaction_fee_currency, wait_time, address, payment_deeplink, payment_deeplink_alt, qr, qr_alt, qr_img, qr_alt_img, access_token, access_url}
GET/CheckPayment/?pos_id={pos_id}&currency={currency} &payment_id={payment_id}&address={address}returns {reference_no, invoice_amount, invoice_currency, currency, amount, payment, confirmations, min_confirmations, confirmed, wait_time, status}
GET/CancelPayment/?pos_id={pos_id}&currency={currency}&payment_id= {payment_id}&address={address}returns {cancelled}
GET/GetCurrencyList/returns [{currency, description}...]
GET /GetTransactions/?offset={offset}&limit={limit}returns [{status, pos_id, payment_id, invoice_currency, invoice_amount, currency, amount, address, type,payment, refund, refund_amount_opened, refund_status, invoice_date, inserted, confirmed, cancelled, double_spending_alert, accept_zero_confirmations, item_name, access_token}...]

Replace {text} with request data: (e.g {pos_id} -> POS1 , {invoice_currency} -> EUR)

pos_idPoint of service identification number for your reference (e.g. POS1, WEB1, ...)
payment_id Payment ID received from StartPayment
reference_noOptional reference number for your record (e.g. invoice or order number)
invoice_no -- deprecated --
invoice_currencyCurrency code for FIAT currency on invoice (EUR, USD..)
invoice_amount Amount on invoice for FIAT currency
currencyCryptocurrency symbol (BTC, ETH..)
accept_zero_confirmations Confirms small payment on zero confirmations (use only when POS is under video surveillance)
userSet user id (available for customers with multiple user accounts)
offsetHow many payments to skip (optional, default 0)
limitLimit how many payments to request (optional, default 20, max 50)
locale Set locale string for requested localization
rateExchange rate
amount_exchangeAmount to exchange to get value on the invoice
network_processing_feeAmount needed to transfer cryptocurrency from merchant to exchange
amountTotal amount to pay
fast_transaction_feeMinimum TX fee/Gas price for fast transacion.
fast_transaction_fee_currency Currency for fast_transaction_fee (e.g.: BTC/byte, Gwei/Gas)
addressAddress for payment
payment_deeplink Deeplink to open wallet app
qrString for qr code that includes cryptocurrency, address and amount
qr_altAlternative string for qr code for legacy wallets including address only
qr_imgURL for qr code image download
qr_alt_img URL for qr_alt code image download
access_tokenAccess token for check payment access
access_urlPublic URL for check payment preview
paymentRecevied amount of payment
confirmationsReceived confirmations of payment
min_confirmations Minimum confirmations to wait (this is informal data. Allways wait till confirmed=true)
wait_timeExpected time to wait
confirmed Is transaction successful and confirmed
cancelledIs cancellation successful
statusStatus info for user about payment status

Return values

API returns results in JSON format.

Get rate

Display informational rate and amount to customer. Should be refreshed on GUI every five seconds till StartPayment is called.



"invoice_amount": "48.25",
"invoice_currency": "EUR",
"currency": "BTC",
"rate": "6467.18",
"amount_exchange": "0.00701574",
"network_processing_fee": "0.00000152",
"amount": "0.00701726",
"fast_transaction_fee": "0.00000009",
"fast_transaction_fee_currency": "BTC/Byte",
"wait_time": "5 seconds"

Start payment

StartPayment is called when customer confirms that will pay in crypto. New address is generated and returned. On return invoice should be finished and transfer window displayed in one edge.



"invoice_amount": "48.25",
"invoice_currency": "EUR",
"currency": "BTC",
"rate": "6467.35",
"amount_exchange": "0.00701496",
"network_processing_fee": "0.00000152",
"amount": "0.00701648",
"fast_transaction_fee": "0.00000009",
"fast_transaction_fee_currency": "BTC/Byte",
"wait_time": "5 seconds",
"address": "33P6AnQfheFxnajXQwFas5jyo1nuhTY4M8",
"qr": "bitcoin:33P6AnQfheFxnajXQwFas5jyo1nuhTY4M8?amount=0.00843504",
"qr_alt": "33P6AnQfheFxnajXQwFas5jyo1nuhTY4M8",
"qr_img": "",
"qr_alt_img": ""

Check payment

CheckPayment checks the payment to blockchain and returns if transaction is confirmed or not. It shoud be refreshed periodically till confirmed=true or CancelPayment must be called if payment will not be made.



"reference_no": "12-23-456",
"invoice_amount": "48.25",
"invoice_currency": "EUR",
"currency": "BTC",
"amount": "0.00668125",
"payment": "0.00000000",
"confirmations": 0,
"min_confirmations": 0,
"confirmed": false,
"status": "Waiting for transaction.",
"wait_time": "5 seconds"

Cancel payment

It is very important that payment is Canceled if transfer will not be made from any reason.



"cancelled": true

Get a list of currencies

GetCurrencyList returns array of currencies for current user.




Get a list of transactions

GetTransactions returns array of transactions for current user.



"status": "Confirmed",
"pos_id": "POS1",
"payment_id": "123e4567-e89b-12d3-a456-426614174000",
"invoice_currency": "EUR",
"invoice_amount": "100",
"currency": "BTC",
"amount": "0.01729569",
"address": "33P6AnQfheFxnajXQwFas5jyo1nuhTY4M8",
"type": "Sell",
"payment": 0.01729569,
"refund": "",
"refund_amount_opened": "",
"refund_status": null,
"invoice_date": null,
"inserted": "2020-03-27 11:00:00",
"confirmed": null,
"cancelled": "2020-03-27 11:00:00",
"double_spending_alert": null,
"accept_zero_confirmations": false,
"item_name": "",

Webhook / Instant Payment Notification (IPN)

Setup webhook notifications URL to be notified when payment status changes.

Payment data is sent in JSON format in the HTTP message body.

Your server URL:

You can setup your webhook notifications URL in your profile under payment settings.

HTTP message body data:


Use a CheckPayment API call to get status information about the payment.
Security warning: when using a reference_no always validate if matches with reference_no in CheckPayment API resposne.