Quickstart - Pillar8 Docs

This guide walks you through integrating Pillar8 into your checkout to start receiving decision packages. The integration is lightweight and requires no changes to your existing payment stack.

Add Pillar8 to Checkout

Install the Pillar8 client in your checkout environment.The component:

Captures checkout context (device, country, cart, payment methods)
Sends a request to the Pillar8 decision engine
Receives a decision package in real time

Call the Optimize API

Your checkout integration sends a request to:POST /api/shopify/checkout-optimize

Example Request

{
  "shop_domain": "example.myshopify.com",
  "cart_value": 85,
  "currency_code": "EUR",
  "country_code": "DE",
  "device_type": "mobile",
  "checkoutToken": "abc123",
  "default_fops": ["card", "paypal", "klarna"],
  "presented_payment_methods": ["card", "paypal", "klarna"]
}

Receive Decision Package

Pillar8 returns a decision package for the checkout session.

Example Response

{
  "status": "ok",
  "ab_variant": "optimize",
  "was_optimized": true,
  "shadow_engine": {
    "scored": [
      { "code": "paypal", "score": 0.82 },
      { "code": "card", "score": 0.74 }
    ]
  },
  "gating_passed": true
}

Apply the Decision

Use the decision package to:

Display an advisory recommendation to the shopper
Highlight or emphasize specific payment methods
Adjust checkout behavior

Send Transaction Outcome (Webhook)

Configure your backend to send transaction outcomes to Pillar8.POST /api/shopify/webhooks/order-completedThis enables Pillar8 to:

Learn from actual payment outcomes
Improve future decisions
Measure impact

Typical integration time: a few hours to a couple of days

What Does Not Change

Your PSP integrations remain unchanged
Your orchestration layer remains unchanged
Your payment routing remains unchanged

Pillar8 operates before payment execution.

Next Steps

See API for full endpoint definitions
Review Architecture to understand system flow
Check Platforms → Shopify for platform-specific details

How It Works

​Example Request

​Example Response

​What Does Not Change

​Next Steps

Example Request

Example Response

What Does Not Change

Next Steps