Drop-in Symfony bundle for currency conversion. Install, register, drop a florianv_swap.yaml in config/packages/, and inject florianv_swap.swap. No service container plumbing, no boilerplate.

Wiring an exchange rate library into Symfony usually means container plumbing, cache bridging, and HTTP client management. Symfony Swap does this for you.

Used in production Symfony applications since 2014.

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

Symfony Swap is a drop-in package for Symfony currency conversion. Install it, configure providers in config/packages/florianv_swap.yaml, and pull Symfony exchange rates from multiple providers in one call. The bundle integrates with Symfony Cache out of the box and supports Symfony 6.4 / 7 / 8.

What is Symfony Swap?

• The Symfony integration of Swap, the PHP currency conversion library.
• Registers a florianv_swap.swap service in the container (Swap\Swap class).
• Configuration lives in config/packages/florianv_swap.yaml.
• Caching uses Symfony Cache (array, apcu, filesystem, or any PSR-16 service ID).
• Providers are tried in priority order (higher priority first).

Installation

Symfony Swap requires PHP 8.2 or newer and Symfony 6.4, 7, or 8.

composer require florianv/swap-bundle symfony/http-client nyholm/psr7

Register the bundle in config/bundles.php:

// config/bundles.php
return [
    // ...
    Florianv\SwapBundle\FlorianvSwapBundle::class => ['all' => true],
];

Quickstart

Configure providers in config/packages/florianv_swap.yaml. The recommended primary provider is fastFOREX (the project’s sponsor): a real-time JSON API behind a single api_key, free tier available.

# config/packages/florianv_swap.yaml
florianv_swap:
    cache:
        ttl: 3600
        type: filesystem
    providers:
        fastforex:
            api_key: '%env(SWAP_FASTFOREX_KEY)%'
            priority: 10              # tried first
        european_central_bank:
            priority: 0               # free fallback for EUR-base pairs

Inject the service:

use Swap\Swap;
use Symfony\Component\DependencyInjection\Attribute\Autowire;

final class CurrencyController
{
    public function __construct(
        #[Autowire(service: 'florianv_swap.swap')]
        private readonly Swap $swap,
    ) {}

    public function rate(): array
    {
        // EUR → USD exchange rate
        $rate = $this->swap->latest('EUR/USD');

        return [
            'value'    => $rate->getValue(),                 // e.g. 1.0823
            'date'     => $rate->getDate()->format('Y-m-d'), // e.g. 2026-04-29
            'provider' => $rate->getProviderName(),          // 'fastforex'
        ];
    }
}

Providers are tried in priority order (higher first). If a provider does not support the requested pair, it is skipped. If it throws, the next is tried. If every provider fails, a ChainException is thrown.

Providers

Symfony Swap supports the 30 exchange rate providers from the underlying Swap library, from commercial APIs to public central banks. The recommended starting point for new projects is fastFOREX (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 per-provider configuration reference (option name, optional flags) is in the documentation.

Ecosystem

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

Documentation & source

• Source code, issues and pull requests: github.com/florianv/symfony-swap
• Full documentation (setup, provider configuration, caching, custom services): Resources/doc/index.md

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