How can I get foreign exchange rates thru an API by using PHP or Ajax?

I need a foreign exchange rate API in PHP for my recent project, in which I need updates after 60 sec.I also need metals like Gold, Silver etc latest exchange rates. So anyone who can I guide me for a PHP endpoint providing latest exchange rates. Any help will be highly appreciated.

I'll strongly recommend you CurrencyFreaks API. It provides foreign currency exchange rate endpoint in multiple languages including PHP and Ajax. It's prominent features are:

• Data is updated every 60 sec.
• You can change the ‘Base’ currency.
• It provides currency exchange rates for 179 currencies worldwide including currencies, metals (Gold, Silver, Palladium, Platinum), and cryptocurrencies.
• Supported codes for the endpoints are Shell, Node.js, Java, Python, PHP, Ruby, JS, C#, Go, C, Swift.

Here's the latest exchange rates endpoint using PHP:

setUrl('https://api.currencyfreaks.com/latest
    ?apikey=YOUR_APIKEY
    &base=GBP
    &symbols=EUR,USD,PKR,INR');
$request->setMethod(HTTP_Request2::METHOD_GET);
$request->setConfig(array(
  'follow_redirects' => TRUE
));
try {
  $response = $request->send();
  if ($response->getStatus() == 200) {
    echo $response->getBody();
  }
  else {
    echo 'Unexpected HTTP status: ' . $response->getStatus() . ' ' .
    $response->getReasonPhrase();
  }
}
catch(HTTP_Request2_Exception $e) {
  echo 'Error: ' . $e->getMessage();
}

For Ajax:

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function() {
  if(this.readyState === 4) {
    console.log(this.responseText);
  }
});

xhr.open("GET", "https://api.currencyfreaks.com/latest
    ?apikey=YOUR_APIKEY
    &base=GBP
    &symbols=EUR,USD,PKR,INR");

xhr.send();

You can also get foreign exchange rate endpoint in other programming languages from here: https://currencyfreaks.com/documentation.html#Latest

I hope this solution will help for your recent project.