CSRF Header Pattern

CSRF Header Pattern: free step-by-step lesson with examples, common mistakes, and interview tips — part of jQuery Tutorial on Toolliyo Academy.

8 min read Updated 8/23/2026

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jQuery Tutorial · Lesson 49 of 100

CSRF Header Pattern

Setup & DOM ✓ → Events Effects AJAX → Perf & Integrate → Ship & Projects

Events Effects AJAX · 2 — Interact · ~6 min · AJAX and APIs

What is this?

Anti-forgery tokens stop cross-site form posts. ASP.NET Core often exposes a token in a cookie or hidden field; jQuery should send it as a request header on mutating AJAX calls.

Why should you care?

QueryVerse POST/PUT/DELETE against same-origin APIs will 400 without the CSRF header in typical setups.

See it live — copy this example

Examples include the jQuery 3.7 CDN. Paste into an HTML file or use Run Example to preview.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>QueryVerse</title>
  <style>
    body { font-family: system-ui, sans-serif; margin: 1.25rem; }
    .box { padding: .75rem; border: 1px solid #ccc; border-radius: 8px; margin: .5rem 0; }
    .muted { color: #666; }
    button { margin-right: .35rem; margin-top: .35rem; }
    input, select, textarea { margin: .25rem 0; }
    table { border-collapse: collapse; width: 100%; }
    th, td { border: 1px solid #ddd; padding: .4rem .55rem; text-align: left; }
    .hidden { display: none; }
    .row-odd { background: #f7f7f7; }
    .active { font-weight: 700; }
    .toast { background: #111; color: #fff; padding: .5rem .75rem; border-radius: 6px; }
  </style>
</head>
<body>
  <meta name="csrf-token" content="demo-token-qv-123">
  <button type="button" id="save">Save (mock headers)</button>
  <pre id="out" class="box muted"></pre>
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<script>
$(function () {
  function csrfToken() {
    return $('meta[name="csrf-token"]').attr('content') || '';
  }
  $('#save').on('click', function () {
    var headers = { 'RequestVerificationToken': csrfToken(), 'X-QueryVerse-CSRF': csrfToken() };
    // Demo: we do not POST to a real antiforgery endpoint; we show the header pattern.
    $('#out').text('Would $.ajax with headers:\n' + JSON.stringify(headers, null, 2));
    $.ajaxSetup({
      headers: { 'RequestVerificationToken': csrfToken() }
    });
    $('#out').append('\n\n$.ajaxSetup applied for subsequent QueryVerse calls (demo).');
  });
});
</script>
</body>
</html>

Run Example »

Edit the code below and click Run to see the result in Toolliyo’s live editor.

Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>QueryVerse</title>
  <style>
    body { font-family: system-ui, sans-serif; margin: 1.25rem; }
    .box { padding: .75rem; border: 1px solid #ccc; border-radius: 8px; margin: .5rem 0; }
    .muted { color: #666; }
    button { margin-right: .35rem; margin-top: .35rem; }
    input, select, textarea { margin: .25rem 0; }
    table { border-collapse: collapse; width: 100%; }
    th, td { border: 1px solid #ddd; padding: .4rem .55rem; text-align: left; }
    .hidden { display: none; }
    .row-odd { background: #f7f7f7; }
    .active { font-weight: 700; }
    .toast { background: #111; color: #fff; padding: .5rem .75rem; border-radius: 6px; }
  </style>
</head>
<body>
  <meta name="csrf-token" content="demo-token-qv-123">
  <button type="button" id="save">Save (mock headers)</button>
  <pre id="out" class="box muted"></pre>
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<script>
$(function () {
  function csrfToken() {
    return $('meta[name="csrf-token"]').attr('content') || '';
  }
  $('#save').on('click', function () {
    var headers = { 'RequestVerificationToken': csrfToken(), 'X-QueryVerse-CSRF': csrfToken() };
    // Demo: we do not POST to a real antiforgery endpoint; we show the header pattern.
    $('#out').text('Would $.ajax with headers:\n' + JSON.stringify(headers, null, 2));
    $.ajaxSetup({
      headers: { 'RequestVerificationToken': csrfToken() }
    });
    $('#out').append('\n\n$.ajaxSetup applied for subsequent QueryVerse calls (demo).');
  });
});
</script>
</body>
</html>

Result