Customer.io Install & Auth

Overview

Set up Customer.io SDK and configure authentication credentials for email, push, SMS, and in-app messaging automation.

Prerequisites

Node.js 18+ or Python 3.10+
Package manager (npm, pnpm, or pip)
Customer.io account with API access
Site ID and API Key from Customer.io dashboard

Instructions

Step 1: Install SDK

# Node.js (Track API)
npm install customerio-node

# Node.js (Journeys Track API - recommended)
npm install @customerio/track

# Python
pip install customerio

Step 2: Configure Authentication

# Set environment variables
export CUSTOMERIO_SITE_ID="your-site-id"
export CUSTOMERIO_API_KEY="your-api-key"

# Or create .env file
cat >> .env << 'EOF'
CUSTOMERIO_SITE_ID=your-site-id
CUSTOMERIO_API_KEY=your-api-key
EOF

Step 3: Verify Connection

import { TrackClient, RegionUS } from '@customerio/track';

const client = new TrackClient(
  process.env.CUSTOMERIO_SITE_ID,
  process.env.CUSTOMERIO_API_KEY,
  { region: RegionUS }
);

// Test by identifying a user
await client.identify('test-user', { email: 'test@example.com' });
console.log('Customer.io connection successful');

Output

Installed SDK package in node_modules or site-packages
Environment variables or .env file with Site ID and API Key
Successful connection verification output

Error Handling

| Error | Cause | Solution | |-------|-------|----------| | Invalid API Key | Incorrect or expired key | Verify key in Customer.io Settings > API Credentials | | Invalid Site ID | Wrong site identifier | Check Site ID in Customer.io Settings | | 401 Unauthorized | Authentication failed | Ensure both Site ID and API Key are correct | | Network Error | Firewall blocking | Ensure outbound HTTPS to track.customer.io allowed | | Module Not Found | Installation failed | Run npm install or pip install again |

Examples

TypeScript Setup

import { TrackClient, RegionUS, RegionEU } from '@customerio/track';

// US region (default)
const client = new TrackClient(
  process.env.CUSTOMERIO_SITE_ID!,
  process.env.CUSTOMERIO_API_KEY!,
  { region: RegionUS }
);

// EU region
const euClient = new TrackClient(
  process.env.CUSTOMERIO_SITE_ID!,
  process.env.CUSTOMERIO_API_KEY!,
  { region: RegionEU }
);

Python Setup

import os
from customerio import CustomerIO

cio = CustomerIO(
    site_id=os.environ.get('CUSTOMERIO_SITE_ID'),
    api_key=os.environ.get('CUSTOMERIO_API_KEY')
)

Resources

Next Steps

After successful auth, proceed to customerio-hello-world for your first API call.