Klaviyo Local Dev Loop

Overview

Set up a fast, reproducible local development workflow for Klaviyo integrations with hot reload, SDK mocking, and integration tests. The loop keeps three concerns separate: a lazily-instantiated SDK client singleton, mocked unit tests that never hit the network, and live integration tests gated behind an opt-in flag so they only run in CI.

Prerequisites

• Completed klaviyo-install-auth setup (provides your private API key)
• Node.js 18+ with npm or pnpm on the PATH
• klaviyo-api package installed as a project dependency
• tsx and vitest installed as dev dependencies for hot reload and tests

Instructions

Follow six steps to stand up the loop. The full file contents for each step — project layout, .env templates, package.json scripts, and the client singleton — live in full walkthrough. The complete test files live in test examples.