PHP Examples

Complete PHP examples for integrating OpenFXRates into your application using cURL and Guzzle.

Installation

Using cURL (Built-in)

cURL comes built-in with PHP. Ensure it's enabled in your php.ini:

extension=curl

Using Guzzle (Recommended)

Install via Composer:

composer require guzzlehttp/guzzle

Example 1: Get Latest Rates (cURL)

Fetch the latest exchange rates using native PHP cURL:

<?php
// Configuration
$apiKey = 'your-api-key-here';
$baseUrl = 'https://api.openfxrates.com';

// Prepare request
$url = $baseUrl . '/latest_rates?base=USD&targets=EUR,GBP,JPY';

// Initialize cURL
$ch = curl_init($url);

// Set cURL options
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'X-API-Key: ' . $apiKey,
    'Content-Type: application/json'
]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);

// Execute request
$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

// Close cURL connection
curl_close($ch);

// Handle response
if ($httpCode === 200) {
    $data = json_decode($response, true);
    
    echo "Base Currency: " . $data['base'] . "\n";
    echo "Date: " . $data['date'] . "\n";
    echo "Rates:\n";
    
    foreach ($data['rates'] as $currency => $rate) {
        echo "  $currency: " . number_format($rate, 4) . "\n";
    }
} else {
    echo "Error: HTTP $httpCode\n";
    echo $response . "\n";
}

Example 2: Get Latest Rates (Guzzle)

Same request using Guzzle HTTP client:

<?php
require 'vendor/autoload.php';

use GuzzleHttp\Client;
use GuzzleHttp\Exception\GuzzleException;

// Configuration
$apiKey = 'your-api-key-here';

try {
    // Create Guzzle client
    $client = new Client([
        'base_uri' => 'https://api.openfxrates.com',
        'timeout'  => 30,
    ]);

    // Make request
    $response = $client->request('GET', '/latest_rates', [
        'query' => [
            'base' => 'USD',
            'targets' => 'EUR,GBP,JPY'
        ],
        'headers' => [
            'X-API-Key' => $apiKey,
        ]
    ]);

    // Parse response
    $data = json_decode($response->getBody(), true);

    echo "Base Currency: " . $data['base'] . "\n";
    echo "Date: " . $data['date'] . "\n";
    echo "Rates:\n";

    foreach ($data['rates'] as $currency => $rate) {
        echo "  $currency: " . number_format($rate, 4) . "\n";
    }

} catch (GuzzleException $e) {
    echo "Request Error: " . $e->getMessage() . "\n";
}

Example 3: Convert Currency

Convert an amount from one currency to multiple target currencies:

<?php
$apiKey = 'your-api-key-here';
$baseUrl = 'https://api.openfxrates.com';

// Conversion parameters
$from = 'USD';
$to = 'EUR,GBP,JPY';
$amount = 100;

// Build URL
$url = $baseUrl . '/convert?' . http_build_query([
    'from' => $from,
    'to' => $to,
    'amount' => $amount
]);

// Initialize cURL
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'X-API-Key: ' . $apiKey
]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Execute
$response = curl_exec($ch);
curl_close($ch);

// Parse and display
$data = json_decode($response, true);

echo "Converting: $amount $from\n";
echo "Results:\n";

foreach ($data['conversions'] as $currency => $convertedAmount) {
    echo "  $currency: " . number_format($convertedAmount, 2) . "\n";
}

Example 4: Get Historical Rates

Fetch exchange rates for a specific date:

<?php
$apiKey = 'your-api-key-here';
$baseUrl = 'https://api.openfxrates.com';

// Historical date
$date = '2024-01-15';
$base = 'USD';

$url = $baseUrl . '/historical_rates?' . http_build_query([
    'base' => $base,
    'date' => $date,
    'targets' => 'EUR,GBP'
]);

// Initialize cURL
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'X-API-Key: ' . $apiKey
]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Execute
$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($httpCode === 200) {
    $data = json_decode($response, true);
    
    echo "Historical Rates for " . $data['date'] . "\n";
    echo "Base: " . $data['base'] . "\n";
    echo "Rates:\n";
    
    foreach ($data['rates'] as $currency => $rate) {
        echo "  $currency: " . number_format($rate, 4) . "\n";
    }
} else {
    $error = json_decode($response, true);
    echo "Error: " . $error['error'] . "\n";
}

Example 5: List All Currencies

Fetch all available currencies:

<?php
$apiKey = 'your-api-key-here';
$baseUrl = 'https://api.openfxrates.com';

$url = $baseUrl . '/currencies';

// Initialize cURL
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'X-API-Key: ' . $apiKey
]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Execute
$response = curl_exec($ch);
curl_close($ch);

// Parse and display
$data = json_decode($response, true);

echo "Available Currencies: " . count($data['currencies']) . "\n\n";

foreach ($data['currencies'] as $currency) {
    echo $currency['code'] . " - " . $currency['name'];
    if (isset($currency['symbol'])) {
        echo " (" . $currency['symbol'] . ")";
    }
    echo "\n";
}

Example 6: Error Handling

Comprehensive error handling for API requests:

<?php
class OpenFXRatesClient {
    private $apiKey;
    private $baseUrl = 'https://api.openfxrates.com';

    public function __construct($apiKey) {
        $this->apiKey = $apiKey;
    }

    public function getLatestRates($base, $targets = null) {
        $params = ['base' => $base];
        if ($targets) {
            $params['targets'] = $targets;
        }

        return $this->makeRequest('/latest_rates', $params);
    }

    private function makeRequest($endpoint, $params = []) {
        $url = $this->baseUrl . $endpoint . '?' . http_build_query($params);

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'X-API-Key: ' . $this->apiKey
        ]);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);

        // Handle cURL errors
        if ($curlError) {
            throw new Exception("Request failed: $curlError");
        }

        // Handle HTTP errors
        if ($httpCode !== 200) {
            $error = json_decode($response, true);
            $message = $error['message'] ?? 'Unknown error';
            throw new Exception("HTTP $httpCode: $message");
        }

        return json_decode($response, true);
    }
}

// Usage
try {
    $client = new OpenFXRatesClient('your-api-key');
    $rates = $client->getLatestRates('USD', 'EUR,GBP,JPY');
    print_r($rates);
} catch (Exception $e) {
    echo "Error: " . $e->getMessage() . "\n";
}

Example 7: Caching Rates

Cache rates to avoid unnecessary API calls:

<?php
class CachedOpenFXRatesClient {
    private $client;
    private $cacheDir = './cache';
    private $cacheTTL = 3600; // 1 hour

    public function __construct($client) {
        $this->client = $client;
        if (!is_dir($this->cacheDir)) {
            mkdir($this->cacheDir, 0755, true);
        }
    }

    public function getLatestRates($base, $targets = null) {
        $cacheKey = 'rates_' . $base . '_' . ($targets ?? 'all');
        $cachePath = $this->cacheDir . '/' . $cacheKey . '.json';

        // Check cache
        if (file_exists($cachePath)) {
            $cacheTime = filemtime($cachePath);
            if (time() - $cacheTime < $this->cacheTTL) {
                return json_decode(file_get_contents($cachePath), true);
            }
        }

        // Fetch from API
        $rates = $this->client->getLatestRates($base, $targets);

        // Save to cache
        file_put_contents($cachePath, json_encode($rates));

        return $rates;
    }
}

// Usage
$client = new OpenFXRatesClient('your-api-key');
$cached = new CachedOpenFXRatesClient($client);

$rates = $cached->getLatestRates('USD', 'EUR,GBP');

Best Practices

Use Environment Variables - Store API keys in environment variables, not in code
Error Handling - Always handle API errors gracefully
Caching - Cache rates to reduce API calls
Timeouts - Set reasonable timeouts for requests
Validation - Validate currency codes before requesting
Rate Limiting - Monitor rate limit headers and back off when needed

Next Steps

JavaScript Examples → - Frontend and Node.js examples
Python Examples → - Python and data science examples
API Reference → - Full endpoint documentation

Installation​

Using cURL (Built-in)​

Using Guzzle (Recommended)​

Example 1: Get Latest Rates (cURL)​

Example 2: Get Latest Rates (Guzzle)​

Example 3: Convert Currency​

Example 4: Get Historical Rates​

Example 5: List All Currencies​

Example 6: Error Handling​

Example 7: Caching Rates​

Best Practices​

Next Steps​