Next.js + Klaviyo integration

Plandalf has no native Klaviyo steps. A Next.js client component opens the checkout; after payment a Send Webhook step can post to Klaviyo's events API directly or to a route handler in your app. Klaviyo flows can also post to a Plandalf catch URL to enrol a profile in a promo.

1. Add the provider and a client button

   Wrap the root layout's children in a client provider that loads the Plandalf script with next/script. Render the checkout button only after the SDK's ready callback has fired, so server rendering never touches window.

2. Sign identity for logged-in users

   If buyers have accounts, sign a Plandalf customer JWT on your server with sub, email and name, and pass it with plandalf.identify(token) before opening checkout. Keep the signing key off the client.

3. Create a Klaviyo private key

   Make a key with the events write scope, and the profiles write scope if you will also import profiles. Put it in a server-only environment variable.

4. Write the route handler

   Accept a POST with a shared secret header, then call Klaviyo's create event endpoint with the revision header, a metric named Plandalf Purchase, the email, a properties object and the amount as value. Return quickly, since Klaviyo answers 202 for queued events.

5. Send the webhook from Plandalf

   Start a sequence on Checkout Completed, add Send Webhook to your handler's URL with the secret in Headers, and a JSON payload using {{trigger.customer_email}}, {{trigger.total_amount}} and {{trigger.invoice_number}}.

6. Build the Klaviyo flow

   In Klaviyo make a flow triggered by the Plandalf Purchase metric. Test with a Stripe test card and Run on test purchases switched on.

• Klaviyo's events API answers 202, which only means the event was queued. Check the Klaviyo profile's activity before assuming a flow ran.
• Klaviyo describes flow webhooks as one-way and requires multi-factor authentication and a Manager, Admin or Owner role to add one.
• Send Webhook has a 30 second reply window and no signature. Verify the secret header and dedupe by invoice number in your handler.
• Unreleased SDK repairs are noted in the Next.js guide for cleanup and countdown ownership, so test route changes against your deployed script.
• A refund does not remove anything in Klaviyo by itself. Add a sequence on Invoice Refunded that posts a refund event if flows should react.

Does Next.js integrate with Klaviyo?

Plandalf has no Klaviyo connector. Your Next.js app opens the Plandalf checkout, and after payment a Send Webhook step or a route handler of yours sends the purchase to Klaviyo's API.

How do I send Plandalf purchases to Klaviyo from Next.js?

Build a Checkout Completed sequence with Send Webhook pointing at a route handler, and have the handler call Klaviyo's create event endpoint with your private key and a metric name.

Can I skip the route handler?

You can call Klaviyo directly from Send Webhook if it can send the headers and content type Klaviyo requires. A handler gives you control over the body, and Zapier's Webhooks are the other relay.

Checked October 26, 2026 against Plandalf's own setup guides and the vendor documentation: Klaviyo API: create event, Klaviyo API: create or update profile, Klaviyo help: understanding webhooks in flows.