# Node.js (official SDK -- NOT @klaviyo/sdk, that's deprecated)
npm install klaviyo-api

# Python
pip install klaviyo-api

# .env (NEVER commit to git)
KLAVIYO_PRIVATE_KEY=pk_***********************************
KLAVIYO_PUBLIC_KEY=UXxxXx    # Only for client-side endpoints

# .gitignore -- ensure secrets are excluded
echo '.env' >> .gitignore
echo '.env.local' >> .gitignore

// src/klaviyo/client.ts
import { ApiKeySession, ProfilesApi, EventsApi, ListsApi } from 'klaviyo-api';

// Create a session with your private API key
const session = new ApiKeySession(process.env.KLAVIYO_PRIVATE_KEY!);

// Instantiate per-resource API clients
export const profilesApi = new ProfilesApi(session);
export const eventsApi = new EventsApi(session);
export const listsApi = new ListsApi(session);

// src/klaviyo/verify.ts
import { ApiKeySession, AccountsApi } from 'klaviyo-api';

async function verifyKlaviyoConnection(): Promise<void> {
  const session = new ApiKeySession(process.env.KLAVIYO_PRIVATE_KEY!);
  const accountsApi = new AccountsApi(session);

  try {
    const accounts = await accountsApi.getAccounts();
    const account = accounts.body.data[0];
    console.log(`Connected to Klaviyo account: ${account.attributes.contactInformation.organizationName}`);
    console.log(`Account ID: ${account.id}`);
  } catch (error: any) {
    if (error.status === 401) {
      console.error('Invalid API key. Check KLAVIYO_PRIVATE_KEY in your .env file.');
    } else if (error.status === 403) {
      console.error('API key lacks required scopes. Generate a new key with full access.');
    } else {
      console.error(`Connection failed: ${error.status} ${error.message}`);
    }
    process.exit(1);
  }
}

verifyKlaviyoConnection();

# Direct cURL test
curl -X GET "https://a.klaviyo.com/api/profiles/" \
  -H "Authorization: Klaviyo-API-Key pk_***" \
  -H "revision: 2024-10-15" \
  -H "Accept: application/vnd.api+json"

# pip install klaviyo-api
from klaviyo_api import KlaviyoAPI

klaviyo = KlaviyoAPI(
    api_key="pk_***",
    max_delay=60,   # Max retry delay in seconds
    max_retries=3   # Number of retries on 429/5xx
)

# Verify connection
accounts = klaviyo.Accounts.get_accounts()
print(f"Connected: {accounts['data'][0]['attributes']['contact_information']['organization_name']}")