Decimal Format

Understand how numerical values are formatted in API responses

Overview

Roxom APIs use standardized decimal formatting to ensure precision and consistency across all financial data. Understanding these formats is crucial for accurate calculations and data interpretation.

Precision Standards

All monetary and price values in Roxom APIs follow these precision standards:

Data Type	Decimal Places	Example
Prices	8	`12345.67890123`
Quantities	8	`1000.50000000`
Balances	8	`9999.99999999`
Percentages	4	`15.2500`
Rates	8	`0.00012345`

String Representation

Example Response

{
  "balance": "1234.56789012",
  "price": "45.67800000",
  "quantity": "100.00000000",
  "feeRate": "0.00100000"
}

Parsing Guidelines

JavaScript/TypeScript

// ❌ Don't use parseFloat (precision loss)
const price = parseFloat("12.34567890"); // 12.345678899999999

// ✅ Use a decimal library
import Decimal from 'decimal.js';
const price = new Decimal("12.34567890"); // Exact precision

// ✅ Or use BigInt for integer calculations
const priceInSatoshis = BigInt("1234567890"); // For 8 decimal places

Python

# ❌ Don't use float (precision loss)
price = float("12.34567890")  # 12.345678899999999

# ✅ Use Decimal for exact precision
from decimal import Decimal
price = Decimal("12.34567890")  # Exact precision

# Example calculation
quantity = Decimal("100.50000000")
total = price * quantity  # Exact result

Java

// ❌ Don't use double (precision loss)
double price = Double.parseDouble("12.34567890");

// ✅ Use BigDecimal for exact precision
import java.math.BigDecimal;
BigDecimal price = new BigDecimal("12.34567890");

// Example calculation with proper scale
BigDecimal quantity = new BigDecimal("100.50000000");
BigDecimal total = price.multiply(quantity);

Currency Pairs and Precision

Different trading pairs may have specific precision requirements:

Major Pairs (8 decimal places)

{
  "BTC/USD": {
    "price": "45000.12345678",
    "minQuantity": "0.00000001"
  }
}

Minor Pairs (6 decimal places)

{
  "ETH/USDT": {
    "price": "3000.123456",
    "minQuantity": "0.000001"
  }
}

Formatting for Display

When displaying values to users, consider appropriate rounding:

// For prices - show relevant decimal places
function formatPrice(priceString, symbol) {
  const price = new Decimal(priceString);
  
  if (symbol.includes('USD')) {
    return price.toFixed(2); // $45,000.12
  } else if (symbol.includes('BTC')) {
    return price.toFixed(8); // 0.12345678 BTC
  }
}

// For balances - avoid trailing zeros
function formatBalance(balanceString) {
  return new Decimal(balanceString).toString(); // Removes trailing zeros
}

Validation

Always validate decimal inputs before sending to the API:

from decimal import Decimal, InvalidOperation

def validate_decimal(value, max_places=8):
    try:
        decimal_value = Decimal(str(value))
        
        # Check decimal places
        if decimal_value.as_tuple().exponent < -max_places:
            raise ValueError(f"Too many decimal places (max {max_places})")
            
        return str(decimal_value)
    except InvalidOperation:
        raise ValueError("Invalid decimal format")

# Example usage
try:
    valid_price = validate_decimal("12.34567890")  # ✅ Valid
    invalid_price = validate_decimal("12.123456789")  # ❌ Too many decimals
except ValueError as e:
    print(f"Validation error: {e}")

Common Pitfalls

Floating Point Arithmetic

Never use native floating-point arithmetic for financial calculations:

// ❌ Wrong - precision loss
0.1 + 0.2 === 0.3; // false!

// ✅ Correct - use decimal library
new Decimal(0.1).plus(0.2).equals(0.3); // true

JSON Parsing

Configure JSON parsers to preserve numerical precision:

import json
from decimal import Decimal

# ❌ Default parsing loses precision
data = json.loads('{"price": "12.34567890"}')
# price becomes float

# ✅ Custom parser preserves strings
def decimal_parser(obj):
    for key, value in obj.items():
        if key in ['price', 'quantity', 'balance']:
            obj[key] = Decimal(value)
    return obj

data = json.loads('{"price": "12.34567890"}', object_hook=decimal_parser)

Database Storage

Use appropriate decimal/numeric types in databases:

-- ✅ Correct - exact precision
CREATE TABLE balances (
    user_id INT,
    amount DECIMAL(20,8)  -- 20 total digits, 8 decimal places
);

-- ❌ Wrong - precision loss
CREATE TABLE balances (
    user_id INT,
    amount FLOAT  -- Approximate, not exact
);

Next Steps

Market Data

Learn how decimal formatting applies to market data endpoints

Last modified on October 9, 2026