Add a cookie consent banner to a Rails app

Cookbook · platform · Last verified 12 November 2026 · View raw markdown (for agents)

In short: paste the live snippet directly after <head> in app/views/layouts/application.html.erb, above csrf_meta_tags, stylesheet_link_tag and javascript_importmap_tags.

Confirmed on a Rails app: the snippet is the first script in the rendered page's <head>.

You need #

• A Cookie Compliance AppID and the live snippet from MCP install.getSnippet or dashboard Integrations → Manual Integration (a new app uses /v2/hu-banner.min.js; an existing app keeps the URL in that snippet). A domain added in the dashboard is published automatically; if the status check still says the app is not published yet, or after later edits, click Publish Now, then copy the snippet. A snippet copied before publishing must be copied again. No account yet? Sign up (free plan, no card); with MCP, call help.startSignup.
• Edit access to app/views/layouts/application.html.erb (and any other layout your pages use).

Where it goes #

1. Copy the live snippet (see above).

2. Open app/views/layouts/application.html.erb and paste the snippet directly after <head>:

   <head>
     <%# Cookie Compliance: first script on the page (paste live snippet here) %>
     <script>
         var huOptions = { "appID": "YOUR_APP_ID", "currentLanguage": "en", "blocking": true, "globalCookie": false };
     </script>
     <script src="https://cdn.hu-manity.co/v2/hu-banner.min.js" type="text/javascript" charset="utf-8"></script>
   
     <title><%= content_for(:title) || "My App" %></title>
     <%= csrf_meta_tags %>
     <%= stylesheet_link_tag :app %>
     <%= javascript_importmap_tags %>
   </head>
   

3. Reload a page. Your trackers stay as they are.

In the stock Rails 8.1 layout, <%= yield :head %> sits before the stylesheet and importmap tags, so a content_for :head block also lands ahead of every script. Check the rendered page to confirm the order in your own layout.

If the snippet is currently at the end of <head>, move it up to directly after <head>.

What the order controls #

The banner holds recognised trackers that load after it until the visitor chooses, in regions whose rule requires consent first. A script placed above the snippet runs straight away, and a script you mark data-hu-category="1" is treated as essential. What runs before consent is your decision, so keep analytics and pixels below the snippet.

Confirm the result #

Build or render the site, then view the page source of the output (not the browser's Elements panel): the huOptions script and hu-banner.min.js are the first two <script> tags in <head> of the rendered page, with no async or defer, and the importmap and your analytics tags come after them.

Then run the browser checks in plain-html in a private window (banner shows, no tracking cookies before the visitor chooses in a region whose rule requires consent first, trackers start after Allow) and, for the full procedure, verify-install. Test from a region your strictest rule covers (for example the EU), or confirm region rules are off.

Gotchas #

• More than one layout. If some pages use a different layout, put the snippet in a shared partial (<%= render "shared/cookie_banner" %>) and render it directly after <head> in each layout.
• Keep a single consent banner. Remove any other one, so visitors see one clear choice.
• Use your own AppID, and copy the snippet again after switching banner engine in the dashboard: changing the setting alone does not update a pasted snippet.

More help #

• Where to put the Cookie Compliance snippet — the placement rule, for the site owner.
• Banner not displayed — what to check when the banner does not show.