Protect an endpoint

First, you need to create the routes (for this example, we'll create a create post endpoint).

You need a GET endpoint (PostController.create()) to display the form and a POST (PostController.processCreate()) to handle the request.

Register the CsrfValidationMiddleware on your post endpoint:

    //...
    middlewares: [new CsrfMiddleware()]
    //...

In your controller:

    public async create({ request, response }: HttpContext) {
        const csrfToken = response.generateCsrfToken(request)
        response = response.setCsrfCookie({ request, response }, csrfToken)

        return response.setResponse({
            contentType: "text/html",
            body: render("./src/templates/path/to/template.html", {
                csrfInput: response.csrfHTMLInput(csrfToken)
            })
        })
    }

    public async processCreate({ request, response }: HttpContext) {
        // ...
    }

In the template:

    <!-- ... -->

    <form action="#" method="post">
        {{csrfInput}}

        <!-- ... -->
    </form>

    <!-- ... -->

What's happening in this example?

First, the user will load the form, and the server will add a little hidden input contening the token in the form.

When the user submits the form, the CsrfMiddleware gets the token and verifies it. If the token isn't defined or the token is invalid (doesn't matches with the request id csrf token or it is expired), a 403 page expired exception is raised.

If the token is valid, the process continues.