A store switching to Klaviyo flows
A shop that sells through a Plandalf checkout wants its post-purchase flows in Klaviyo but cannot cut over the newsletter on a single day. New buyers land in both lists until the Klaviyo flows are proven.
Native on one side, webhook on the other
Mailchimp + Klaviyo integration
A Plandalf checkout writes the buyer to Mailchimp natively and to Klaviyo through its API, so both lists fill while you decide which one wins.
No credit card required. No coding required.
Mailchimp
KlaviyoDoes Mailchimp integrate with Klaviyo?
Plandalf does not sync Mailchimp with Klaviyo. It can write one purchase to both: native Mailchimp steps, plus a Send Webhook step that calls Klaviyo's API. A Klaviyo flow can post a profile to a Plandalf catch URL, and a Mailchimp subscribe can start a sequence that forwards the contact.
What moves between Mailchimp and Klaviyo
| Event | From and to | Through | What happens |
|---|---|---|---|
| Checkout completed | Plandalf → Mailchimp | Native step | Add or Update Contact, Add Tags to Contact and Record Event are the built-in steps. Purchases arrive in Mailchimp as events on the contact, not as ecommerce orders. |
| Checkout completed | Plandalf → Klaviyo | Webhook | A Send Webhook step posts a profile to Klaviyo's profile import endpoint. Klaviyo wants an Authorization header that begins Klaviyo-API-Key, a revision header and a content type of application/vnd.api+json, and the body is a JSON:API document of type profile. |
| Consent to marketing | Plandalf → Klaviyo | Webhook | The profile import request has no field for marketing consent. Subscribing someone is a second call to Klaviyo's bulk subscribe endpoint, which records the consent you pass and honours the target list's double opt-in setting. |
| Contact subscribed | Mailchimp → Klaviyo | Webhook | The native Mailchimp trigger starts a sequence whose Send Webhook step creates or updates the Klaviyo profile for the new audience member. |
| Flow webhook | Klaviyo → Plandalf | Webhook | A Klaviyo flow's Webhook action posts JSON to a Plandalf catch URL. Klaviyo allows only POST, requires HTTPS and lets you add headers, and only events that can trigger a flow can feed it. |
| Invoice refunded | Plandalf → Mailchimp | Native step | Remove access on refund takes the Mailchimp tag off. Klaviyo has no Plandalf step, so clearing a property or list there is a webhook call you add yourself. |
Keep Mailchimp running while Klaviyo fills up
This is the overlap setup for a shop or creator moving lists. You need a Mailchimp key and a Klaviyo private API key with permission to write profiles.
Connect Mailchimp in Plandalf
Go to Automation, Marketplace, find Mailchimp and paste the API key with its
-us21style suffix. Check you see Mailchimp connected.Make a private key in Klaviyo
Create a private API key with profile write access, and a second scope for subscriptions if you plan to record consent. Keep it out of any page or email.
Build the sequence
Under My Sequences choose Plandalf, Checkout Completed and your offer. Pick a recent checkout on the Test tab.
Add the Mailchimp steps
Add Mailchimp, Add or Update Contact and a tag step, with
{{trigger.customer_email}}as the email. Put the offer name in a tag so a Customer Journey can aim at it.Add the Klaviyo call
Add Send Webhook with POST to Klaviyo's profile import address. Set the three headers, then write the JSON payload with
email,first_nameandlast_nameinside the profile attributes.Compare the two profiles
Run both tests with your own email, then open the contact in Mailchimp and the profile in Klaviyo. When Klaviyo is the winner, delete the Mailchimp steps; the sequence keeps working without them.
What sellers do with Mailchimp and Klaviyo
Creators who keep Mailchimp for the archive
Years of subscribers and journeys live in Mailchimp, while the new product launches are built in Klaviyo. Tagging the buyer in Mailchimp keeps the old segments honest, and the Klaviyo profile feeds the new ones.
Limits and gotchas
- Klaviyo documents a burst limit of 75 requests a second, a steady limit of 750 a minute and a 100KB payload cap on profile import, which is plenty for one buyer per request.
- Importing a profile does not subscribe it. Send the subscribe call only for buyers who agreed to marketing email, because that request states their consent.
- Plandalf has no Klaviyo app. The private key lives in the Send Webhook step's headers, so use a key scoped to what the step needs.
- A Klaviyo flow webhook is POST-only and needs HTTPS, and Klaviyo requires two-step authentication for the people who add or edit webhooks.
- Mailchimp's journey events carry no revenue, so keep the order total in an event property or in the Klaviyo profile properties.
Mailchimp and Klaviyo: common questions
- Does Mailchimp integrate with Klaviyo?
- Plandalf does not connect them to each other. It can write the same buyer to both, using native Mailchimp steps and a Send Webhook call to Klaviyo's API. Klaviyo's own integrations list is the place to look for a direct link.
- How do I connect Mailchimp to Klaviyo?
- With Plandalf, build a sequence on Checkout Completed that has Mailchimp steps and a Send Webhook step aimed at Klaviyo's profile import endpoint. The recipe on this page lists the headers.
- Can I migrate from Mailchimp to Klaviyo with Plandalf?
- Plandalf does not move existing contacts. It keeps new buyers flowing into both tools during the overlap so neither list goes stale while you rebuild automations in Klaviyo.
- Will Klaviyo know the buyer agreed to emails?
- Only if you tell it. Profile import creates the profile; a separate subscribe request records consent and should be used only for buyers who opted in.
Guides for this pair
Start your 14-day free trialMore from Mailchimp and Klaviyo
- Mailchimp + ActiveCampaignOne Plandalf checkout tags the buyer in Mailchimp with a built-in step and adds them to ActiveCampaign through a webhook call.
- Mailchimp + DripMailchimp and Drip both have built-in Plandalf steps, so one checkout can fill both while you move your automations across.
- Mailchimp + FlodeskTag the buyer in Mailchimp with a native step and put them in a Flodesk segment with a Send Webhook call, from the same checkout.
- Shopify + KlaviyoKlaviyo handles your Shopify orders itself. Plandalf adds an offer beside the cart and writes its buyers into Klaviyo as events through Send Webhook.
- Stripe + KlaviyoStripe takes the payment, Plandalf runs the checkout, and a Send Webhook step can hand the purchase to Klaviyo as an event.
- Webflow + KlaviyoWebflow hosts the buy button, Plandalf takes payment, and a Send Webhook step can push the buyer or the order into Klaviyo.
Checked October 26, 2026 against Plandalf's own setup guides and the vendor documentation: Klaviyo API: create or update profile (profile import), Klaviyo API: bulk subscribe profiles, Klaviyo: how to add a webhook action to a flow.