> For the complete documentation index, see [llms.txt](https://omnify.gitbook.io/omnify-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://omnify.gitbook.io/omnify-docs/deep-dive/omnipay.md).

# OmniPay

Omnify's payment suite and infrastructure is all hosted in OmniPay. It paves the way for full payments, receipts, refunds, installments, and instant revenue withdrawals. Accessible from [pay.omnify.finance](http://pay.omnify.finance/) and [app.omnify.finance/payments](https://app.omnify.finance/payments).

<figure><img src="/files/KCyunjU78qg9iGU8NDSl" alt=""><figcaption><p>OmniPay Logo</p></figcaption></figure>

In this section we will cover making payments, paying installments, withdrawing revenues, and checking if a payment was made and if a payment was refunded. Payments are made in the native token of the network you are on. You can find a list of all Omnify services' tiers and fees at [omnify.finance/fees](https://omnify.finance/fees).&#x20;

Start by downloading the [OmniPay interface](https://github.com/OmniKobra/Omnify/blob/main/Omni/Contracts/Omnify/src/interfaces/paymentsInterface.sol) found in our github repo.

### Making a payment

```solidity
function makePayment(
    string memory _id, // payment ID, must not be a duplicate
    uint256 _amount, // amount due in wei
    address _vendor, // vendor address
    bool _isInstallments, // true if payment is a downpayment with installments
    uint256 _fullAmount, // if is installments place the full amount due here, use _amount if full payment (in wei)
    uint8 _installmentPeriod // how many months the installment period is max is 120
) external payable;
```

{% stepper %}
{% step %}

### Define OmniPay variable

```solidity
IPayments99 public omnipay = IPayments99(0xEe47e2484342eA7Bcf13B9e6d4F9d53B28F1b724); // address on Avalanche C-Chain
```

{% endstep %}

{% step %}

### Get Omnify's fee / payment

```solidity
uint256 public feePerPayment = omnipay.feePerPayment();
```

{% endstep %}

{% step %}

### Call `makePayment`&#x20;

<pre class="language-solidity"><code class="lang-solidity"><strong>uint256 public _amount = 1 * 10 ** 15;
</strong><strong>omnipay.makePayment{value: feePerPayment + _amount}(
</strong>'ID1', // payment ID, must not be a duplicate
_amount, // amount due in wei
address(0x6BF6D002b5140b7CE0A0a4993621ecE52271e5f0), // vendor address
false, // true if payment is a downpayment with installments
_amount, // if is installments place the full amount due here, if not use _amount (in wei)
0 // how many months the installment period is max is 120
);
</code></pre>

{% endstep %}
{% endstepper %}

### Checking if a payment was made or refunded via ID

We lookup a payment by its ID from the OmniPay contract by calling `lookupPayment`. The return value is a `Payment` struct containing all details about the payment.

```solidity
struct Payment {
    string id; // payment ID
    uint256 amount; // amount due in Wei
    address customer; // customer address
    address vendor; //  vendor address
    bool isPaid; // true if the payment exists and has been paid
    bool isRefunded; // true if the payment was refunded
    bool isInstallments; // true if the payment contains installments
    uint256 fullAmount; // the full amount of the payment
    uint256 amountPerInstallment; // amount due per month 
    uint8 installmentPeriod; // the installment period in months
    uint8 paidInstallments; // how many installments have been paid 
    uint8 remainingInstallments; // how many installments remain
    uint256 datePaid; // date the payment was made
    uint256 dateLastInstallmentPaid; // date the last installment was paid
}
```

```solidity
IPayments99 public omnipay = IPayments99(0xEe47e2484342eA7Bcf13B9e6d4F9d53B28F1b724);
IPayments99.Payment public payment = omnipay.lookupPayment('ID1'); 
bool public isPaid = payment.isPaid == true; // check if paid
bool public isRefunded = payment.isRefunded == true; // check if refunded
```

### Paying installments

When paying an installment be sure to get the amount per installment of that payment, and the fee Omnify charges per installment.&#x20;

```solidity
IPayments99 public omnipay = IPayments99(0xEe47e2484342eA7Bcf13B9e6d4F9d53B28F1b724);
IPayments99.Payment public payment = omnipay.lookupPayment('ID1');
uint256 public feePerInstallment = omnipay.feePerInstallment();
uint256 public amountPerInstallment = payment.amountPerInstallment;
omnipay.payInstallment{value: amountPerInstallment + feePerInstallment}('ID1');
```

Additionally, if its the last installment it is required to calculate the final installment by subtracting the paid amount so far from the full amount. Replace `amountPerInstallment` with `paidSoFar` and `installmentAmount` .

```solidity
IPayments99 public omnipay = IPayments99(0xEe47e2484342eA7Bcf13B9e6d4F9d53B28F1b724);
IPayments99.Payment public payment = omnipay.lookupPayment('ID1');
uint256 public feePerInstallment = omnipay.feePerInstallment();
uint256 public paidSoFar = payment.paidInstallments * payment.amountPerInstallment;
uint256 public installmentAmount = payment.fullAmount - paidSoFar;
omnipay.payInstallment{value: installmentAmount + feePerInstallment}('ID1');
```

### Withdrawing Revenues

Any vendor can withdraw any amount of their revenues whenever they wish by simply calling `withdrawBalance` , granted they've received payments equal or more than the amount they are trying to withdraw.

```solidity
IPayments99 public omnipay = IPayments99(0xEe47e2484342eA7Bcf13B9e6d4F9d53B28F1b724);
omnipay.withdrawBalance(1 * 10 ** 15);
```

***All our crypto payment needs are covered with OmniPay.*****♾️**