Callbacks

Crypto2B can generate notifications for the client's system with information about operations (for example, deposits, withdrawals, service operations, address checks). Callbacks are used for this.

Setup

If the client wants to use the callback mechanism to track the processing status of operations, the callback URL must be configured in the personal account.

Then, while processing crypto payments, Crypto2B will send JSON-formatted notifications to this URL with all the necessary information about the transaction.

Callback content

Crypto2B callbacks contain all the important information about the transaction:

• operation type
• processing status
• currency
• address
• amount
• transaction hash in the blockchain
• number of confirmations
• fee

and so on

Callback examples

Deposit

{
  "data": {
    "type": "Deposit",
    "id": 123456,
    "status": "Success",
    "date": "2024-01-15T10:30:00Z",
    "clientDepositId": "client-deposit-001",
    "error": null,
    "instrument": {
      "currencyShortName": "USDT",
      "transportProtocol": "trc20"
    },
    "address": {
      "address": "TExampleDepositAddress1234567890abc",
      "tag": null,
      "foreignId": "user-12345",
      "senderAddress": "TExampleSenderAddress0987654321xyz"
    },
    "transaction": {
      "approach": "FullProcessing",
      "hash": "abc123def456abc123def456abc123def456abc123def456abc123def456abcd",
      "amount": 1000.50,
      "confirmations": 21,
      "amlRiskGrade": "Low"
    },
    "fees": [
      {
        "type": "Commercial",
        "currencyShortName": "USDT",
        "transportProtocol": "trc20",
        "amount": 5.00
      }
    ]
  }
}

Withdrawal

{
  "data": {
    "type": "Withdrawal",
    "id": 789012,
    "status": "Success",
    "date": "2024-01-15T14:45:00Z",
    "paymentOrderId": "withdrawal-order-001",
    "foreignId": "user-withdrawal-789",
    "error": null,
    "instrument": {
      "currencyShortName": "BTC",
      "transportProtocol": "btc"
    },
    "address": {
      "address": "bc1qexamplewithdrawaladdress000000000000000",
      "tag": null
    },
    "transaction": {
      "approach": "FullProcessing",
      "hash": "00000000000000000000abcdef1234567890abcdef1234567890abcdef123456",
      "amount": 0.05,
      "confirmations": 6,
      "amlRiskGrade": null
    },
    "fees": [
      {
        "type": "Commercial",
        "currencyShortName": "BTC",
        "transportProtocol": "btc",
        "amount": 0.0001
      },
      {
        "type": "Technical",
        "currencyShortName": "BTC",
        "transportProtocol": "btc",
        "amount": 0.00005
      }
    ]
  }
}

Service Operation

{
  "data": {
    "type": "Service",
    "id": 345678,
    "soType": "Common",
    "status": "Success",
    "date": "2024-01-15T16:00:00Z",
    "error": null,
    "instrument": {
      "currencyShortName": "ETH",
      "transportProtocol": "erc20"
    },
    "sender": "0x0000000000000000000000000000000000000001",
    "recipient": "0x0000000000000000000000000000000000000002",
    "transaction": {
      "hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
      "amount": 2.5,
      "confirmations": 35
    },
    "technicalFee": {
      "currencyShortName": "ETH",
      "transportProtocol": "erc20",
      "amount": 0.002
    }
  }
}

Address Check

{
  "data": {
    "type": "AddressCheck",
    "checkId": "550e8400-e29b-41d4-a716-446655440000",
    "address": "TJYeasypBnB2x5hLTpYPQZ6YR9ZL3hLj6b",
    "status": "Completed",
    "amlRiskGrade": "Low",
    "description": "Exchange wallet",
    "currency": "USDT",
    "protocol": "Tron",
    "feeAmount": 0.5,
    "feeCurrencyShortName": "USDT",
    "timestamp": "2024-01-15T10:30:00Z",
    "errorCode": null,
    "errorMessage": null
  }
}

Field description

Field	Description
type	Operation type: Deposit, Withdrawal, Service, AddressCheck
id	Unique operation identifier in the system
status	Operation processing status
date	Date and time of the operation (ISO 8601)
instrument	Information about the currency and protocol
address	Transaction address and additional parameters
transaction	Blockchain transaction details
fees	Array of fees (commercial, technical)
error	Error message (if any)

Fields specific to deposits

Field	Description
clientDepositId	Deposit ID in the client's system
address.foreignId	External user identifier
address.senderAddress	Sender address

Fields specific to withdrawals

Field	Description
paymentOrderId	Payment order ID
foreignId	External operation identifier

Fields specific to service operations

Field	Description
soType	Service operation type (for example, Common)
sender	Sender address
recipient	Recipient address
technicalFee	Technical fee for the operation

Address check callback fields

The address check callback does not contain the common id, date, instrument, address, transaction and fees fields. Its structure is described in the Address Check section.

Important note

Deduplication

Keep in mind that, due to implementation specifics, the same callback may sometimes be sent more than once. Always track transaction identifiers to avoid double spending and similar issues.