Broker

One of the use cases that Nexus allows you to build is a broker platform, more specifically a portal/app on which customers can buy and sell crypto-currencies. Thanks to our solution, you will be able to design and develop your service without the need to worry about the lower-level inner workings of crypto exchanges, performing transactions and compliance. Just call our APIs and it will be done for you!

Another advantage of employing Nexus as a middle layer interface concerns the customer's experience: for instance, on the hot wallet provided to you different crypto-currencies can be stored. If you have enough funds there and a customer decides to buy an amount that you already have available, they will experience near instant delivery! Not enough funds? No worries, our Tradebot can help you to automatically keep a specific amount of funds always available to offer an even slicker experience to your customers.

Below you can see a general diagram showing how this model would work for you and your customers.

One important aspect to keep in mind concerns the compliance risk: indeed, in this model the crypto-currency can be received from external sources as well, meaning that an higher risk has to be taken into account and more careful compliance checks should be carried out to avoid incurring into frauds and /or losses.

Account

This term in Nexus has a different meaning from the usual one. When we talk about an Account, we mean a pair of Withdraw and Deposit address, explained in more detail in the subsections below.

Native Accounts

An account using the native crypto of its blockchain, e.g. ETH on Ethereum.

Non-Native Accounts

An account able to use a non-native crypto on its blockchain, e.g. USDT on Ethereum, in addition to its native crypto.

Withdraw address

The withdraw address is the one the Customer provides once they want to have an account on your platform. Basically, this will be their private wallet, where they will receive the crypto-currency bought through the system.

Deposit address

Upon the creation of an Account, Nexus automatically assigns a deposit address to couple together with the withdraw one. This address will be used to receive the crypto send by the customer.

Transactions

Buy

What happens when one of your customer wants to buy crypto-currency on Nexus? The figure below describes on a high level the workflow needed to accomplish that.

In Nexus, a buy transaction can pass through as many as 8 statuses. However, not all transactions reach the final completed status.

• BuyInitiated: The customer starts the buy process, receiving information on price, fee and crypto-currency amounts. These are temporary "frozen", in order to give the customer the time to execute the payment on their side.
• SendDelay: The crypto-currency amount is locked in the Nexus hot wallet, in order to guarantee the delivery to the customer. To define how the SendDelay status works for every crypto-currency, please refer to the Pricing section.
• Sending: In the same way of the SendDelay status, Sending also reserves the crypto-currency amount on the Nexus hot wallet. This status is reached when the payment signal has been received from the payment method chosen by the customer. Nexus will then execute the blockchain transaction to move the crypto-currency to the customer's wallet.
• ToCancel: The status indicates that the customer has requested to cancel their payment. At this stage, the system is still processing the cancellation, which may take some time. If the cancellation is successful, the transaction status will update to BuyCancelled. However, if the wallet has already processed the payment before the cancellation is finalized, the transaction may still move to BuyCompleted.
• BuyCancelled: This status is automatically assigned after a buy transaction has been Initiated, but in the following 30 minutes the payment signal has not been received from the payment method chosen by the customer.
• BuyCompleted: Once the blockchain transaction has been successfully completed, the status is updated from Sending to BuyCompleted. Once this status is reached, the buy transaction has been finally completed.
• Deleted: The status Deleted is used when the system receives a transaction from a customer, but before the transaction reaches a final status such as BuyCompleted, the customer’s account is not active. In this case, the transaction cannot proceed to completion and is instead marked as deleted.
• ByIncasso: The ByIncasso status indicates that a BUY transaction has been initiated, and the cryptocurrency has already been delivered to the customer, but the payment has not yet been settled. This status is typically set manually by an Operator after a period of non-settlement, indicating that the customer still owes the payment. It serves as a flag for outstanding debt and may impact the customer's ability to initiate new transactions, such as imposing limits or restrictions.

As long as the transaction status is not BuyCompleted, it can be set to Blocked or be Cancelled. The Blocked status can be used to park transactions that are not trusted, even when the payment arrives (typically in the case of fraud). Afterwards, they can be set again to Sending or be Cancelled. The Cancelled status will also be automatically set When Initiated transactions do not receive a payment confirmation within 30 minutes.

NOTE

After each transaction status update, a callback function is offered by Nexus to your backend system. The callback URL can be set for each Payment method in the settings.

Sell

Now that your customers are happy with the profit yielded by the crypto-currencies they bought, it is time for them to cash out and receive the corresponding amount in their bank account. Again, the figure below shows the necessary steps to achieve such goal.

As in the Buy transaction, also selling crypto-currencies is done in steps. The following are the available statuses in Nexus and their meaning.

• SellInitiated: when the customer initiates a Sell transaction, they will receive information about the price, fees and payout value. The information yielded are reserved and "frozen" for an amount of time, which you can define for every payment method. Note: if your customer fails to actually send the crypto within this time-frame, the previously mentioned data will be updated at the time of reception (only if the price change is negative for the broker).
• Confirming: transitional status in which the hot wallet notifies Nexus about the number of confirmations on the blockchain, after the customer has sent the crypto-currency to their deposit wallet.
• ToPayout: when the desired number of confirmations on the blockchain has been reached, the customer may receive the payment on his/her bank account.
• PayoutOnHold: status that can be used for compliance and blockchain latency purposes or if customer's' limits are reached. E.g: to mark transactions that need further investigation or in case a transaction was received too late.
• PayoutConfirming: intermediate status that can be used to implement a 4-eyes security mechanism, with Nexus as a backend.
• Blocked: if the customer chose to use a very low mining fee, it is possible for a transaction to take days or even weeks to get confirmed. If it takes more than 2 hours to get a confirmation, a transaction will be automatically assigned this status. When the confirmation rounds are eventually completed the status will be automatically updated to ToPayout. However, the price will be updated with the current one at time of confirmation (only if the price change is negative for the broker).
• SellCancelled: this status is automatically assigned after a Sell transaction has been Initiated, but in the following 30 minutes no crypto-currency has been transferred.
• SellCompleted: final status that confirm that the Sell transaction has been successfully carried out.
• Deleted: The status Deleted is used when the system receives a transaction from a customer, but before the transaction reaches a final status such as BuyCompleted, the customer’s account is not active. In this case, the transaction cannot proceed to completion and is instead marked as deleted.
• Returned: The status indicated that a transaction with status PayoutOnHold has been sent back to the customer as a crypto transaction. In this case, the value is returned in cryptocurrency with the possibility of being adjusted for the current market price. Once the return is processed, the transaction is marked as Returned
• GiftSending: Transitional status in which Nexus is sending crypto from the hot wallet to the customer’s receiving address.
• GiftCompleted: Final status that confirm that the gift transaction has been successfully carried out.

Customers can also send crypto-currency directly to their Deposit address without creating a Sell transaction. In this case, Nexus will automatically detect a change in the deposit address balance and create a Sell transaction with the Confirming status. The price, fees and payout values are the ones from the moment of reception of such amount.

Merchant

What if for example a store or a person only accepts fiat, but a customer wants to pay in crypto. The Broker solution offers the option to create a Merchant transaction for this specific scenario. Merchant transactions enable a customer to pay a merchant, which only accepts fiat, in crypto. This is possible by allowing the customer to send the crypto amount to the address provided by Nexus. After it has been sent, Nexus recognizes this and updates the transaction with the necessary information to enable you to pay out the corresponding fiat amount to the merchant's bank account, allowing the customer to pay in crypto, and the merchant to be paid in fiat.

A Merchant transaction is similar to a Sell transaction and share the same transaction statuses as explained with the Sell transaction, but unlike a Sell transactions, a customer cannot send crypto-currency directly to a Deposit address without a Merchant transaction being created first. A Sell and Merchant transaction also differs in the sense that instead of the corresponding fiat amount of the crypto sold by the customer being paid out to the customer, it should be paid out to the merchant.

NOTE

When creating a Merchant transaction, the merchant's account needs to be specified and not the customer. It is not necessary to have an account for the customer in Nexus. A Merchant account can be created manually via the portal by creating a customer with the merchant's details, and selecting to create a Merchant account for that customer on the customer view.

Gift

There might be cases in which you want to reward your customers (loyalty, constructive feedback etc.) with an amount in crypto-currency or fiat currency. In Nexus such operation is possible through a gift transaction, which has to be carried out by one of your Operators. To carry out such operation, the following details need to be provided. Nexus then determines the following for each Gift:

• Fees: Nexus does not calculate any Fees for Gift transaction.
• Price: If the Gift is in Cryptocurrency, Nexus requests the buy price from the Price Exchange.
• Payout Amount: Nexus multiplies the requested amount with the sell price and subtracts the Fees from the result.

Tradebot

Terminology and detailed explanations have been separated. You can follow the links below:

• For the general concept and setup flow, see Tradebot overview
• For broker-specific behavior and settings, see Tradebot — Broker model