Estimate Payment Amount

POST

/rates/calculate/

Calculate the equivalent amount in a target cryptocurrency based on a source amount and currency. This endpoint is useful for showing users how much cryptocurrency they need to pay for a fiat amount.

Authentication

Requires OAuth 2.0 authentication with read scope.

Request Body

Parameter	Type	Required	Description
`amount`	decimal	Yes	The amount to convert
`from_currency`	string	Yes	Source currency code (e.g., "USD")
`to_currency`	string	Yes	Target currency code (e.g., "USDTERC20")
`is_fee_paid_by_user`	boolean	No	Whether user pays the fee (default: true)

Example Request

curl -X POST https://api.cryptofuse.io/rates/calculate/ \
  -H "Authorization: Bearer your_access_token" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 100.00,
    "from_currency": "USD",
    "to_currency": "USDTERC20",
    "is_fee_paid_by_user": true
  }'

Response

Success Response (200 OK)

{
  "from_currency": "USD",
  "from_amount": "100.00",
  "to_currency": "USDTERC20",
  "to_amount": "100.050000",
  "exchange_rate": "0.9999",
  "fee_amount": "0.050000",
  "fee_currency": "USDTERC20",
  "total_amount": "100.050000",
  "rate_expires_at": "2025-01-15T10:05:00Z",
  "calculation_timestamp": "2025-01-15T10:00:00Z"
}

Response Fields

Field	Type	Description
`from_currency`	string	Source currency code
`from_amount`	string	Source amount
`to_currency`	string	Target cryptocurrency code
`to_amount`	string	Converted amount (before fees)
`exchange_rate`	string	Exchange rate used
`fee_amount`	string	Fee amount (if user pays)
`total_amount`	string	Total amount user needs to pay
`rate_expires_at`	datetime	When this rate expires

Error Responses

400 Bad Request

{
  "error": {
    "code": "invalid_request",
    "message": "Invalid request parameters",
    "details": {
      "amount": ["Must be greater than 0"]
    }
  }
}

422 Unprocessable Entity

{
  "error": {
    "code": "invalid_currency",
    "message": "Currency not supported",
    "details": {
      "currency": "FAKECOIN",
      "supported_currencies": ["USDTERC20", "USDCERC20", "DAIERC20"]
    }
  }
}

Supported Currency Pairs

From Currencies (Fiat)

USD - US Dollar
EUR - Euro
GBP - British Pound

To Currencies (Crypto)

USDTERC20 - Tether USD on Ethereum
USDCERC20 - USD Coin on Ethereum
DAIERC20 - DAI Stablecoin on Ethereum
ETH - Ethereum
WETH - Wrapped Ethereum

Fee Calculation

When is_fee_paid_by_user is true:

Base Amount: 100.00 USD
Exchange Rate: 0.9999 (1 USD = 0.9999 USDT)
Converted Amount: 99.99 USDT
Network Fee: 0.05 USDT
Transaction Fee: 0.01 USDT (0.01%)
Total Fee: 0.06 USDT
Total Amount: 100.05 USDT

When is_fee_paid_by_user is false:

Base Amount: 100.00 USD
Exchange Rate: 0.9999
Converted Amount: 99.99 USDT
Fees paid by merchant
User Pays: 99.99 USDT

Rate Validity

Exchange rates are updated every minute
Rates are typically valid for 5 minutes
Always check rate_expires_at field
For volatile pairs, rates may expire sooner

Usage Examples

E-commerce Checkout

// Show customer how much crypto to pay for $100 order
async function calculateCryptoAmount(orderAmount) {
  const response = await fetch('https://api.cryptofuse.io/rates/calculate/', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${accessToken}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      amount: orderAmount,
      from_currency: 'USD',
      to_currency: 'USDTERC20',
      is_fee_paid_by_user: true
    })
  });

  const data = await response.json();
  
  // Display to customer
  console.log(`Pay ${data.total_amount} ${data.to_currency}`);
  console.log(`Exchange rate: 1 USD = ${data.exchange_rate} USDT`);
  console.log(`Includes ${data.fee_amount} USDT in fees`);
}

Gaming/Casino Deposits

def show_deposit_options(deposit_usd):
    """Show player crypto deposit amounts for different currencies."""
    
    currencies = ['USDTERC20', 'USDCERC20', 'DAIERC20']
    options = []
    
    for currency in currencies:
        response = requests.post(
            'https://api.cryptofuse.io/rates/calculate/',
            json={
                'amount': deposit_usd,
                'from_currency': 'USD',
                'to_currency': currency,
                'is_fee_paid_by_user': True
            },
            headers={'Authorization': f'Bearer {access_token}'}
        )
        
        if response.status_code == 200:
            data = response.json()
            options.append({
                'currency': currency,
                'amount': data['total_amount'],
                'expires': data['rate_expires_at']
            })
    
    return options

# Show deposit options for $100
deposit_options = show_deposit_options(100.00)
for option in deposit_options:
    print(f"Deposit {option['amount']} {option['currency']}")

Important Notes

This endpoint does not create a payment - it only calculates amounts
Use the calculated amount within the validity period
Actual payment amount may differ slightly due to rate changes
For stablecoins (USDT, USDC, DAI), rates are typically near 1:1 with USD
Network congestion may affect fee calculations