How to Make a cURL API Request in PHP

Learn how to send API requests using PHP's cURL extension , perfect for third-party API integrations.

📌 What Is cURL?

cURL is a powerful PHP library that allows you to connect and communicate with external servers through URLs. It supports a variety of protocols including HTTP, HTTPS, FTP, and more , making it a key tool for API integration.

🔎 Example 1: Basic GET Request

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://api.example.com/data");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);

echo $response;
?>

This example fetches data from a public API and outputs the response.

🛡️ Adding Headers (Authentication)

<?php
$ch = curl_init("https://api.example.com/user");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
  "Authorization: Bearer YOUR_API_KEY",
  "Accept: application/json"
]);
$response = curl_exec($ch);
curl_close($ch);

$data = json_decode($response, true);
print_r($data);
?>

This snippet demonstrates how to include headers for APIs requiring authentication.

📤 Example 2: POST Request with Data

<?php
$data = [
  "name" => "John",
  "email" => "[email protected]"
];

$ch = curl_init("https://api.example.com/submit");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));

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

echo $response;
?>

This example sends form data as a POST request to an API endpoint.

🧾 Sending JSON Payloads

<?php
$data = json_encode([
  "username" => "demo",
  "password" => "secret"
]);

$ch = curl_init("https://api.example.com/login");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
  "Content-Type: application/json",
  "Content-Length: " . strlen($data)
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);

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

echo $response;
?>

This demonstrates how to send raw JSON using a POST request , a common requirement in modern APIs.

❗ Error Handling

<?php
$ch = curl_init("https://api.example.com/test");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);

if (curl_errno($ch)) {
  echo "cURL error: " . curl_error($ch);
} else {
  echo $response;
}

curl_close($ch);
?>

Always check for errors when working with cURL to ensure robustness.