Webhook in PHP: Overview, Advantages, Use Cases & Real-World Example

<?php
// webhook.php

$input = @file_get_contents("php://input");
$data = json_decode($input, true);

// Optional: Verify Razorpay signature (for security)
$signature = $_SERVER['HTTP_X_RAZORPAY_SIGNATURE'];
$secret = "your_secret_key";

function verifySignature($data, $signature, $secret) {
    $generated = hash_hmac('sha256', $data, $secret);
    return hash_equals($generated, $signature);
}

if (verifySignature($input, $signature, $secret)) {
    // Process the event
    $event = $data['event'];

    if ($event == "payment.captured") {
        $payment_id = $data['payload']['payment']['entity']['id'];
        $amount = $data['payload']['payment']['entity']['amount'];

        // Store payment or trigger order processing
        file_put_contents("logs.txt", "Payment received: $payment_id - ₹" . ($amount / 100));
    }
    http_response_code(200);
} else {
    // Invalid Signature
    http_response_code(403);
    echo "Signature verification failed.";
}

// receive_sales_webhook.php
$input = json_decode(file_get_contents("php://input"), true);

if (!empty($input['orderNumber'])) {
    $partyName = addslashes($input['partyName']);
    $orderNumber = addslashes($input['orderNumber']);
    $voucherAmount = floatval($input['voucherAmount']);
    $orderDate = strtotime($input['orderDate']);

    $con = mysqli_connect("localhost", "root", "", "your_db");
    $sql = "INSERT INTO pbi_tallySalesList (partyName, orderNumber, tVoucherAmount, orderDate)
            VALUES ('$partyName', '$orderNumber', '$voucherAmount', '$orderDate')";
    mysqli_query($con, $sql);

    http_response_code(200);
    echo "Sales record received.";
} else {
    http_response_code(400);
    echo "Invalid webhook data.";
}

// webhook_stock_update.php
$data = json_decode(file_get_contents("php://input"), true);

if (isset($data['product_id'], $data['new_stock'])) {
    $productId = intval($data['product_id']);
    $stock = intval($data['new_stock']);

    $con = mysqli_connect("localhost", "root", "", "your_db");
    $update = "UPDATE product_inventory SET stock = $stock WHERE product_id = $productId";
    mysqli_query($con, $update);

    echo "Stock updated.";
} else {
    http_response_code(422);
    echo "Missing fields";
}

// google_form_webhook.php
$input = json_decode(file_get_contents("php://input"), true);
$name = $input['name'] ?? '';
$feedback = $input['message'] ?? '';

$con = mysqli_connect("localhost", "root", "", "your_db");
mysqli_query($con, "INSERT INTO feedbacks (name, message) VALUES ('$name', '$feedback')");
echo "Thank you for your feedback!";

$data = ['zone' => 'North', 'target' => 100000, 'actual' => 54000];
$ch = curl_init("https://yourinternalapi.com/notify_target.php");
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);