customerio-hello-world

# Customer.io Hello World ## Overview Create a minimal working Customer.io integration: identify a user (create/update their profile), track an event, and send a transactional email. This covers the three fundamental Customer.io operations. ## Prerequisites - `customerio-node` installed (`npm install customerio-node`) - `CUSTOMERIO_SITE_ID` and `CUSTOMERIO_TRACK_API_KEY` configured - `CUSTOMERIO_APP_API_KEY` configured (for transactional email example) ## Instructions ### Step 1: Identify a User (Create/Update Profile) ```typescript // hello-customerio.ts import { TrackClient, RegionUS } from "customerio-node"; const cio = new TrackClient( process.env.CUSTOMERIO_SITE_ID!, process.env.CUSTOMERIO_TRACK_API_KEY!, { region: RegionUS } ); // identify() creates the user if they don't exist, or updates if they do. // The first argument is your internal user ID (immutable — use DB primary key). await cio.identify("user-123", { email: "hello@example.com", // Required for email campaigns first_name: "Jane", last_name: "Doe", plan: "pro", created_at: Math.floor(Date.now() / 1000), // Unix seconds, NOT milliseconds }); console.log("User identified in Customer.io"); ``` **Key rules:** - `id` (first arg) should be your immutable database ID — never use email as ID - `email` attribute is required if you want to send email campaigns - `created_at` must be Unix timestamp in **seconds** (not ms) — `Math.floor(Date.now() / 1000)` - All custom attributes are ...