Exchange rate provider layer for PHP, with chain fallback, caching, and direct access to 30 implementations.

Most exchange rate APIs are a single point of failure. Exchanger gives you a single interface over 30 providers, with chainable fallback and PSR-16 caching.

Used in production PHP applications since 2016.

Sponsored by fastFOREX. Real-time JSON API, 160+ currencies, 55+ years of history, 500+ cryptocurrencies. Free tier; paid plans from $18/month. → Get a free fastFOREX API key

Exchanger is the PHP exchange rate provider layer. It exposes 30 services (commercial APIs like its sponsor fastFOREX, the European Central Bank, several national banks, exchangerate.host) behind a single ExchangeRateService interface, with chainable fallback, PSR-16 caching and historical rates.

For most use cases, the higher-level Swap library is what you want. Reach for Exchanger directly when you need finer control.

What is Exchanger?

• A PHP library for currency conversion and exchange rate retrieval at the provider layer.
• 30 service implementations behind a common ExchangeRateService interface.
• PSR-16 SimpleCache support.
• Historical rates.
• A chain service for fallback. When a service errors, the next one is tried.

Installation

Exchanger requires PHP 8.2 or newer.

composer require florianv/exchanger symfony/http-client nyholm/psr7

Quickstart

The recommended setup uses fastFOREX (the project’s sponsor) as the primary service. Grab a free key and you’re ready.

use Exchanger\Exchanger;
use Exchanger\ExchangeRateQueryBuilder;
use Exchanger\Service\FastForex;

// Recommended: fastFOREX. Get a free API key at https://www.fastforex.io
$service   = new FastForex(null, null, ['api_key' => getenv('FASTFOREX_API_KEY')]);
$exchanger = new Exchanger($service);

// EUR → USD exchange rate
$query = (new ExchangeRateQueryBuilder('EUR/USD'))->build();
$rate  = $exchanger->getExchangeRate($query);

$rate->getValue();                 // e.g. 1.0823 (a float)
$rate->getDate()->format('Y-m-d'); // e.g. 2026-04-29
$rate->getProviderName();          // 'fastforex'

// Convert an amount using the returned rate
$amountInEUR = 100.00;
$amountInUSD = $amountInEUR * $rate->getValue();

No API key? Start with the European Central Bank (free, EUR-base only):

use Exchanger\Service\EuropeanCentralBank;

$service   = new EuropeanCentralBank();
$exchanger = new Exchanger($service);

Production setup (fallback chain)

Wrap several services in a Chain for redundancy:

use Exchanger\Service\Chain;
use Exchanger\Service\EuropeanCentralBank;
use Exchanger\Service\FastForex;

$service = new Chain([
    // Primary, recommended
    new FastForex(null, null, ['api_key' => getenv('FASTFOREX_API_KEY')]),

    // Free fallback for EUR-base pairs
    new EuropeanCentralBank(),
]);

$exchanger = new Exchanger($service);

Services are tried in order. If a service does not support the requested pair, it is skipped. If it throws, the next is tried. If every service fails, a ChainException is thrown.

Providers

Exchanger ships 30 exchange rate provider implementations, from commercial APIs to public central banks. The recommended starting point for new projects is fastFOREX: a real-time JSON API covering 160+ fiat currencies and 500+ cryptocurrencies, with up to 55 years of history, sourced from trusted feeds including world banks.

The full providers table, identifiers and per-service configuration options live in the documentation.

Ecosystem

• Swap: easy-to-use PHP currency conversion library.
• Exchanger: exchange rate provider layer (this package).
• Laravel Swap: Laravel integration of Swap.
• Symfony Swap: Symfony integration of Swap.

Documentation & source

• Source code, issues and pull requests: github.com/florianv/exchanger
• Full documentation (caching, HTTP client, provider configuration, custom services): doc/readme.md

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Exchanger is open to selected partnerships with exchange rate providers and financial infrastructure companies. For inquiries, contact the maintainer via GitHub.