klaviyo

name	klaviyo
description	Klaviyo email/SMS marketing - profiles, events, flows, segmentation
when-to-use	When integrating Klaviyo for email/SMS marketing
user-invocable	false
effort	medium

Klaviyo E-Commerce Marketing Skill

For integrating Klaviyo email/SMS marketing - customer profiles, event tracking, campaigns, flows, and segmentation.

Sources: Klaviyo API Docs | API Reference

---

Why Klaviyo

Feature	Benefit
E-commerce Native	Built for online stores, deep integrations
Event-Based	Trigger flows from any customer action
Segmentation	Advanced filtering on behavior + properties
Email + SMS	Unified platform for both channels
Analytics	Revenue attribution per campaign

---

API Basics

Base URLs

Type	URL
Server-side (Private)	https://a.klaviyo.com/api
Client-side (Public)	https://a.klaviyo.com/client

Authentication

// Server-side: Private API Key
const headers = {
  "Authorization": "Klaviyo-API-Key pk_xxxxxxxxxxxxxxxxxxxxxxxx",
  "Content-Type": "application/json",
  "revision": "2024-10-15",  // API version
};

// Client-side: Public API Key (6 characters)
const publicKey = "XXXXXX";  // Company ID
// Use as query param: ?company_id=XXXXXX

API Key Scopes

Scope	Access
Read-only	View data only
Full	Read + write (default)
Custom	Specific permissions

---

Installation

Node.js

npm install klaviyo-api

// lib/klaviyo.ts
import { ApiClient, EventsApi, ProfilesApi, ListsApi } from "klaviyo-api";

const client = new ApiClient();
client.setApiKey(process.env.KLAVIYO_PRIVATE_KEY!);

export const eventsApi = new EventsApi(client);
export const profilesApi = new ProfilesApi(client);
export const listsApi = new ListsApi(client);

Python

pip install klaviyo-api

# lib/klaviyo.py
from klaviyo_api import KlaviyoAPI

klaviyo = KlaviyoAPI(
    api_key=os.environ["KLAVIYO_PRIVATE_KEY"],
    max_delay=60,
    max_retries=3
)

Direct HTTP (Any Language)

// lib/klaviyo.ts
const KLAVIYO_BASE_URL = "https://a.klaviyo.com/api";

async function klaviyoRequest(
  endpoint: string,
  method: "GET" | "POST" | "PATCH" | "DELETE" = "GET",
  body?: object
) {
  const response = await fetch(`${KLAVIYO_BASE_URL}${endpoint}`, {
    method,
    headers: {
      Authorization: `Klaviyo-API-Key ${process.env.KLAVIYO_PRIVATE_KEY}`,
      "Content-Type": "application/json",
      revision: "2024-10-15",
    },
    body: body ? JSON.stringify(body) : undefined,
  });

  if (!response.ok) {
    const error = await response.json();
    throw new Error(`Klaviyo API error: ${JSON.stringify(error)}`);
  }

  return response.json();
}

---

Profiles (Customers)

Create/Update Profile

// Upsert profile (create or update)
async function upsertProfile(data: ProfileInput) {
  return klaviyoRequest("/profiles", "POST", {
    data: {
      type: "profile",
      attributes: {
        email: data.email,
        phone_number: data.phone, // E.164 format: [phone]
        first_name: data.firstName,
        last_name: data.lastName,
        properties: {
          // Custom properties
          lifetime_value: data.ltv,
          plan: data.plan,
          signup_source: data.source,
        },
        location: {
          city: data.city,
          region: data.state,
          country: data.country,
          zip: data.zip,
        },
      },
    },
  });
}

# Python
def upsert_profile(data):
    return klaviyo.Profiles.create_or_update_profile({
        "data": {
            "type": "profile",
            "attributes": {
                "email": data["email"],
                "first_name": data["first_name"],
                "last_name": data["last_name"],
                "properties": {
                    "plan": data.get("plan"),
                }
            }
        }
    })

Get Profile

async function getProfileByEmail(email: string) {
  const response = await klaviyoRequest(
    `/profiles?filter=equals(email,"${email}")`
  );
  return response.data[0];
}

async function getProfileById(profileId: string) {
  return klaviyoRequest(`/profiles/${profileId}`);
}

Update Profile Properties

async function updateProfileProperties(
  profileId: string,
  properties: Record<string, any>
) {
  return klaviyoRequest(`/profiles/${profileId}`, "PATCH", {
    data: {
      type: "profile",
      id: profileId,
      attributes: {
        properties,
      },
    },
  });
}

// Usage
await updateProfileProperties("profile_id", {
  last_purchase_date: new Date().toISOString(),
  total_orders: 5,
  vip_status: true,
});

---

Events (Tracking)

Track Event (Server-Side)

async function trackEvent(data: EventInput) {
  return klaviyoRequest("/events", "POST", {
    data: {
      type: "event",
      attributes: {
        profile: {
          data: {
            type: "profile",
            attributes: {
              email: data.email,
              // or phone_number, or external_id
            },
          },
        },
        metric: {
          data: {
            type: "metric",
            attributes: {
              name: data.eventName,
            },
          },
        },
        properties: data.properties,
        value: data.value, // For revenue tracking
        unique_id: data.uniqueId, // Deduplication
        time: data.timestamp || new Date().toISOString(),
      },
    },
  });
}

Common E-Commerce Events

// Viewed Product
await trackEvent({
  email: customer.email,
  eventName: "Viewed Product",
  properties: {
    ProductID: product.id,
    ProductName: product.name,
    ProductURL: product.url,
    ImageURL: product.image,
    Price: product.price,
    Categories: product.categories,
  },
});

// Added to Cart
await trackEvent({
  email: customer.email,
  eventName: "Added to Cart",
  properties: {
    ProductID: product.id,
    ProductName: product.name,
    Quantity: quantity,
    Price: product.price,
    CartTotal: cart.total,
    ItemNames: cart.items.map(i => i.name),
  },
  value: product.price * quantity,
});

// Started Checkout
await trackEvent({
  email: customer.email,
  eventName: "Started Checkout",
  properties: {
    CheckoutURL: checkout.url,
    ItemCount: cart.itemCount,
    Categories: cart.categories,
    ItemNames: cart.items.map(i => i.name),
  },
  value: cart.total,
});

// Placed Order
await trackEvent({
  email: customer.email,
  eventName: "Placed Order",
  properties: {
    OrderId: order.id,
    ItemCount: order.itemCount,
    Categories: order.categories,
    ItemNames: order.items.map(i => i.name),
    Items: order.items.map(i => ({
      ProductID: i.productId,
      ProductName: i.name,
      Quantity: i.quantity,
      Price: i.price,
      ImageURL: i.image,
      ProductURL: i.url,
    })),
    BillingAddress: order.billingAddress,
    ShippingAddress: order.shippingAddress,
  },
  value: order.total,
  uniqueId: order.id, // Prevent duplicate orders
});

// Fulfilled Order
await trackEvent({
  email: customer.email,
  eventName: "Fulfilled Order",
  properties: {
    OrderId: order.id,
    TrackingNumber: fulfillment.trackingNumber,
    TrackingURL: fulfillment.trackingUrl,
    Carrier: fulfillment.carrier,
  },
});

// Cancelled Order
await trackEvent({
  email: customer.email,
  eventName: "Cancelled Order",
  properties: {
    OrderId: order.id,
    Reason: cancellation.reason,
  },
  value: -order.total, // Negative value for refunds
});

Client-Side Tracking (JavaScript)

<!-- Add to your site -->
<script async src="https://static.klaviyo.com/onsite/js/klaviyo.js?company_id=XXXXXX"></script>

<script>
  // Identify user
  klaviyo.identify({
    email: "[e-mail]",
    first_name: "John",
    last_name: "Doe",
  });

  // Track event
  klaviyo.track("Viewed Product", {
    ProductID: "prod_123",
    ProductName: "Blue T-Shirt",
    Price: 29.99,
  });

  // Track with value
  klaviyo.track("Added to Cart", {
    ProductID: "prod_123",
    ProductName: "Blue T-Shirt",
    Price: 29.99,
    $value: 29.99,  // Revenue tracking
  });
</script>

---

Lists & Segments

Add Profile to List

async function addToList(listId: string, emails: string[]) {
  return klaviyoRequest(`/lists/${listId}/relationships/profiles`, "POST", {
    data: emails.map(email => ({
      type: "profile",
      attributes: { email },
    })),
  });
}

// By profile ID
async function addProfileToList(listId: string, profileId: string) {
  return klaviyoRequest(`/lists/${listId}/relationships/profiles`, "POST", {
    data: [{ type: "profile", id: profileId }],
  });
}

Remove from List

async function removeFromList(listId: string, profileId: string) {
  return klaviyoRequest(
    `/lists/${listId}/relationships/profiles`,
    "DELETE",
    {
      data: [{ type: "profile", id: profileId }],
    }
  );
}

Get List Members

async function getListMembers(listId: string, cursor?: string) {
  const params = new URLSearchParams({
    "page[size]": "100",
  });
  if (cursor) {
    params.set("page[cursor]", cursor);
  }

  return klaviyoRequest(`/lists/${listId}/profiles?${params}`);
}

Create List

async function createList(name: string) {
  return klaviyoRequest("/lists", "POST", {
    data: {
      type: "list",
      attributes: { name },
    },
  });
}

---

Campaigns

Get Campaigns

async function getCampaigns(status?: "draft" | "scheduled" | "sent") {
  const params = new URLSearchParams();
  if (status) {
    params.set("filter", `equals(status,"${status}")`);
  }

  return klaviyoRequest(`/campaigns?${params}`);
}

Get Campaign Performance

async function getCampaignMetrics(campaignId: string) {
  return klaviyoRequest(
    `/campaign-recipient-estimations/${campaignId}`,
    "GET"
  );
}

---

Flows (Automations)

Get Flows

async function getFlows() {
  return klaviyoRequest("/flows");
}

async function getFlowById(flowId: string) {
  return klaviyoRequest(`/flows/${flowId}`);
}

Common Flow Triggers

Flow Type	Trigger Event
Welcome Series	Added to List
Abandoned Cart	Added to Cart + No Purchase
Browse Abandon	Viewed Product + No Cart
Post-Purchase	Placed Order
Winback	No Order in X Days
Review Request	Fulfilled Order

---

Webhooks

Create Webhook

async function createWebhook(data: WebhookInput) {
  return klaviyoRequest("/webhooks", "POST", {
    data: {
      type: "webhook",
      attributes: {
        name: data.name,
        endpoint_url: data.url,
        secret_key: data.secret,
        topics: data.topics, // e.g., ["profile.created", "event.created"]
      },
    },
  });
}

Webhook Topics

Topic	Trigger
profile.created	New profile created
profile.updated	Profile properties changed
profile.merged	Profiles merged
event.created	New event tracked
list.member.added	Profile added to list
list.member.removed	Profile removed from list

Verify Webhook Signature

import crypto from "crypto";

function verifyKlaviyoWebhook(
  payload: string,
  signature: string,
  secret: string
): boolean {
  const expectedSignature = crypto
    .createHmac("sha256", secret)
    .update(payload)
    .digest("base64");

  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(expectedSignature)
  );
}

// Express handler
app.post("/webhooks/klaviyo", (req, res) => {
  const signature = req.headers["klaviyo-webhook-signature"] as string;

  if (!verifyKlaviyoWebhook(JSON.stringify(req.body), signature, WEBHOOK_SECRET)) {
    return res.status(401).json({ error: "Invalid signature" });
  }

  const { type, data } = req.body;

  switch (type) {
    case "profile.created":
      handleNewProfile(data);
      break;
    case "event.created":
      handleNewEvent(data);
      break;
  }

  res.status(200).json({ received: true });
});

---

Rate Limits

Window	Limit
Burst	75 requests/second
Steady	700 requests/minute

Handle Rate Limiting

async function klaviyoRequestWithRetry(
  endpoint: string,
  method: "GET" | "POST" | "PATCH" | "DELETE" = "GET",
  body?: object,
  retries = 3
): Promise<any> {
  for (let attempt = 0; attempt < retries; attempt++) {
    const response = await fetch(`${KLAVIYO_BASE_URL}${endpoint}`, {
      method,
      headers: {
        Authorization: `Klaviyo-API-Key ${process.env.KLAVIYO_PRIVATE_KEY}`,
        "Content-Type": "application/json",
        revision: "2024-10-15",
      },
      body: body ? JSON.stringify(body) : undefined,
    });

    if (response.status === 429) {
      const retryAfter = parseInt(response.headers.get("Retry-After") || "5");
      await new Promise(r => setTimeout(r, retryAfter * 1000));
      continue;
    }

    if (!response.ok) {
      throw new Error(`Klaviyo error: ${response.status}`);
    }

    return response.json();
  }

  throw new Error("Max retries exceeded");
}

---

Pagination

async function getAllProfiles() {
  const profiles = [];
  let cursor: string | undefined;

  do {
    const params = new URLSearchParams({ "page[size]": "100" });
    if (cursor) {
      params.set("page[cursor]", cursor);
    }

    const response = await klaviyoRequest(`/profiles?${params}`);
    profiles.push(...response.data);

    cursor = response.links?.next
      ? new URL(response.links.next).searchParams.get("page[cursor]")
      : undefined;
  } while (cursor);

  return profiles;
}

---

Filtering & Sorting

// Filter by date
const recentEvents = await klaviyoRequest(
  `/events?filter=greater-than(datetime,2024-01-01T00:00:00Z)`
);

// Filter by property
const vipProfiles = await klaviyoRequest(
  `/profiles?filter=equals(properties.vip_status,true)`
);

// Multiple filters (AND)
const filtered = await klaviyoRequest(
  `/profiles?filter=and(equals(properties.plan,"pro"),greater-than(properties.ltv,1000))`
);

// Sorting
const sorted = await klaviyoRequest(
  `/profiles?sort=-created`  // Descending by created date
);

// Sparse fieldsets (only return specific fields)
const sparse = await klaviyoRequest(
  `/profiles?fields[profile]=email,first_name,properties`
);

---

Integration Patterns

E-Commerce Order Sync

// After order is placed
async function syncOrderToKlaviyo(order: Order) {
  // 1. Upsert customer profile
  await upsertProfile({
    email: order.customerEmail,
    firstName: order.customerFirstName,
    lastName: order.customerLastName,
    phone: order.customerPhone,
  });

  // 2. Update lifetime metrics
  await updateProfileProperties(
    await getProfileIdByEmail(order.customerEmail),
    {
      last_order_date: new Date().toISOString(),
      total_orders: order.customerOrderCount,
      lifetime_value: order.customerLifetimeValue,
    }
  );

  // 3. Track order event
  await trackEvent({
    email: order.customerEmail,
    eventName: "Placed Order",
    properties: {
      OrderId: order.id,
      Items: order.items,
      // ... other properties
    },
    value: order.total,
    uniqueId: order.id,
  });
}

Subscription Status Sync

// When subscription changes
async function syncSubscriptionStatus(user: User, status: string) {
  await updateProfileProperties(user.klaviyoProfileId, {
    subscription_status: status,
    subscription_plan: user.plan,
    subscription_updated_at: new Date().toISOString(),
  });

  await trackEvent({
    email: user.email,
    eventName: `Subscription ${status}`,
    properties: {
      plan: user.plan,
      mrr: user.mrr,
    },
    value: status === "cancelled" ? -user.mrr : user.mrr,
  });
}

---

Environment Variables

# .env
KLAVIYO_PRIVATE_KEY=pk_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
KLAVIYO_PUBLIC_KEY=XXXXXX
KLAVIYO_WEBHOOK_SECRET=your_webhook_secret

Add to credentials.md:

'KLAVIYO_PRIVATE_KEY': r'pk_[a-f0-9]{32}',
'KLAVIYO_PUBLIC_KEY': r'[A-Z0-9]{6}',

---

Checklist

Setup

• Klaviyo account created
• Private API key generated
• Public API key noted (company ID)
• API revision set in headers

Integration

• Profile sync on signup/update
• Key events tracked (view, cart, order)
• Order events include Items array
• Revenue tracked with $value
• Unique IDs for deduplication

Testing

• Test profile creation
• Test event tracking
• Verify events in Klaviyo dashboard
• Test webhook delivery
• Test rate limit handling

---

Anti-Patterns

• Missing email/phone - Every profile needs at least one identifier
• Duplicate events - Use unique_id for orders/transactions
• Missing Items array - Required for product recommendations
• Client-side only - Server-side tracking is more reliable
• Ignoring rate limits - Implement exponential backoff
• Hardcoded API keys - Use environment variables
• Missing revenue tracking - Include $value for ROI attribution