Add a newsletter sign-up

By the end of this recipe your site has a sign-up box that adds readers to Buttondown or Kit, each credited to the campaign, referrer and landing page that first brought them. A honeypot and a per-address budget keep bots from filling your list with addresses nobody owns.

Remember where visitors land#

A reader's campaign is recorded on the page views before they subscribe, so the cookie that holds it comes first. Follow Keep the first and last touch for the signed cookie and the attribution() middleware.

Subscribe readers#

Follow Run a newsletter list. Its router already installs attribution() from the previous step, and its action hands the reader's touch to the platform with toCampaign, so the campaign arrives with every new subscriber.

Guard the sign-up#

A form with one email field gives a spam score nothing to read, so the honeypot and the budget are the layers that fit. Follow Set a trap no person fills and Budget each address, then mount trap on both subscribe routes and callerBudget("subscribe", 5) on its action, as Mount the guards on the route does. renderSubscribe issues the honeypot fields into the form, and the action answers isFailure(ctx.honeypotOutcome) with "Send it again." before it validates.

Test it#

Test each stage as its guide does: Test against the memory list checks who reached the list, and Test the guards posts a signed honeypot token through the router.

Where to go next#

• Receive and send webhooks — the signatures and replay store behind the confirmation webhook.

• Charge for your app — the same touches credited on a checkout.

• @sdxc/newsletter — the Kit provider's options and every error code.