Currencies API Guide: Real-Time and Historical Exchange Rate Data

Why Exchange Rate Data Matters

Access to consistent and accurate exchange rates is critical for trading platforms, payment processors, fintech applications, and analytics systems. Whether you're supporting crypto-fiat conversions, cross-border payments, or historical auditing, reliable data is essential for precision, compliance, and performance.

This guide covers how the Currencies API delivers both real-time and historical FX data — along with how to use it across various applications.

What Are Exchange Rates?

Exchange rates define the value of one currency relative to another. This applies to:

• Crypto-to-crypto pairs (e.g., ETH/BTC)
• Crypto-to-fiat pairs (e.g., BTC/USD)
• Fiat-to-fiat pairs (e.g., EUR/JPY)

Rates are influenced by trading volume, market depth, exchange-specific pricing models, regulations, and market behavior.

Why Rates Differ Between Platforms

Exchange rate discrepancies occur due to:

• Differing order book liquidity across exchanges
• Fee structures and spreads applied by platforms
• Geographic and regulatory constraints
• Timing differences and data quality
• Arbitrage behavior and user demand

A unified API that aggregates and normalizes data helps maintain consistency across use cases.

Common Use Cases for Exchange Rate Data

Currencies API supports a wide range of real-world applications across multiple industries:

• Remittance Services: Deliver accurate real-time FX rates for money transfers. Use historical data for audits, dispute resolution, and regulatory reporting.
• Travel & Hospitality: Convert booking prices in real time at checkout. Use timestamped historical rates for refunds, reconciliations, and multi-currency reporting.
• E-commerce & Marketplaces: Display prices in local currencies based on current FX rates. Automate currency conversion for global product catalogs and billing systems.
• Trading & Investment Platforms: Feed real-time rates into trading UIs, backtesting tools, and portfolio trackers. Support both fiat and crypto markets.
• DeFi & Web3: Integrate live FX rates into smart contracts, on-chain oracles, and liquidity management tools.
• Financial Services & Banking: Support multi-currency wallets, payment processing, and compliance tools with accurate and auditable exchange rates.

Real-Time and Historical Data

Real-Time Exchange Rates

• 100ms update intervals
• Bid, ask, mid-market, and VWAP pricing
• Streaming support via WebSocket and FIX
• Delivered via REST, WebSocket, and JSON-RPC
• Suitable for pricing engines, trading interfaces, and conversions at checkout

Historical Exchange Rates

• Time series data with granularity from 1 second to 1 day
• OHLC format and VWAP available
• 14+ years of data
• Supports auditing, backtesting, and reconciliation workflows
• Delivered via REST API with flexible parameters

Developer Best Practices

When working with exchange rate data:

• Timestamp validation: Always use the latest rates for live operations
• Error handling: Implement fallback logic in case of downtime or latency
• Rate limits: Throttle requests to match your plan
• Data verification: Ensure pricing accuracy before using in financial workflows

Example Queries

Get a Specific Exchange Rate

1{
2  "time_period_start": "2016-01-01T00:00:00.0000000Z",
3  "time_period_end": "2016-01-01T00:01:00.0000000Z",
4  "rate_open": 430.58,
5  "rate_high": 430.58,
6  "rate_low": 430.58,
7  "rate_close": 430.58
8}

Get All Current Rates for a Base Asset

1{
2  "asset_id_base": "BTC",
3  "rates": [...],
4  "time": "2017-08-09T14:31:37.0520000Z"
5}
6

Get Historical Time Series Data

1{
2  "time": "2025-02-13T10:07:38.2687211Z",
3  "asset_id_base": "BTC",
4  "asset_id_quote": "USD",
5  "rate": 10000
6}
7

Start Using Exchange Rate Data

The Currencies API provides unified access to both live and historical exchange rate data — with low latency, full auditability, and support for crypto and fiat pairs.

Explore the docs or get an API key to begin integrating accurate FX data into your system.