Callbacks

Callback are essential part of the flow, notifications for important events which you need to bind to and listen.

Here is the structure of the callbacks you'll receive when there is in an update to a transaction:

key	explanation
uuid	uuid of the transaction in NexaStake
reference_number	reference number of the transaction in your system
payment_method	id of the payment method
blockchain_txId	id of the transaction in the blockchain
chain	name of the chain
address	the receiver address
counterAddress	the sender address
sandbox	indicates if the transaction is sandbox or not
paid_amount	the actual amount paid confirmed from the blockchain
fiat_paid_amount	the actual paid amount confirmed from the blockchain converted to fiat
fiat_amout	the amount in fiat
fiat_currency	the fiat currenct
converted_amount	the converted amount from the fiat currency into the blockchain token
fee	platform fee
safe	if transaction is marked as safe in our AML/CTF checks
payment_method_name	Name of the payment method in our system
blockchain	Name of the blockchain
status	enum TransactionStatus : int { case PENDING = 0; case CONFIRMED = 1; case CANCELED = 2; case UNDERPAID = 3; case REFUNDED = 4; case UNSAFE_TO_PROCESS = 5; }
created_at	Date on which the transaction was created
customer	Details of the transaction customer

Here is the same in actual response send from us as an example:

{
  "uuid": "b9d2d8c3-10f5-4825-b738-e6d822c3ec78",
  "reference_number": "trc20-73dsiUPVrNcgkEMV6JwAiBzkYAbgXw",
  "payment_method": 1,
  "blockchain_txId": "b2560f41aa5fb8ab1463af8c2bb7371448d63167c5b74014b53959140f7b7d0d",
  "chain": "tron-testnet",
  "address": "TUwojPNpnDqXkJhksFKxAAgYj7F2SseUb8",
  "counterAddress": "TYfDaL7Fvop7vJ26m9N5aUi2W6fGbutPdf",
  "sandbox": 1,
  "paid_amount"; 1.20,
  "fiat_paid_amount": 56,
  "fiat_amount": null,
  "fiat_currency": null,
  "converted_amount": 21.57,
  "fee": 3.3,
  "safe": 1,
  "payment_method_name": "TokenDeposit",
  "blockchain_name": "Tron",
  "status": 1,
  "created_at": "2025-07-15T17:41:33.000000Z",
  "customer": {
    "uuid": "cc0a2b2c-592f-4293-8ad9-5a5d9fee2997",
    "name": "Misho Pie",
    "email": "[email protected]"
  }
}

Important note!

NexaStake will make up to 5 tries to send a callback to your system until it receives Response status code from your system - 200 After those 5 tries are attempted and if we never receive success response code from your side we will stop further retries on that transaction notification.

Our system will also send notification email to the brand owner that there was failed transaction with detailed explanation.