> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pillar8.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Constraints

This page describes what Pillar8 changes and what it does not.

## What Pillar8 Changes

Pillar8 changes checkout decisioning by introducing a real-time decision layer that evaluates each session independently and returns a decision package to influence shopper behavior.

## What Pillar8 Does Not Change

<Columns cols={2}>
  <Card title="Not Changed" icon="lock">
    * PSP integrations
    * Orchestration layers
    * Payment routing
    * Payment processing
  </Card>
</Columns>

## Data Scope

Pillar8 uses checkout-level context including:

* Device type
* Country and currency
* Cart value
* Available payment methods
* Transaction outcome

<Note>
  The optimize API does not require cardholder data.
</Note>

## Platform Constraints

Execution depends on checkout environment capabilities.

**Supported in all environments:**

* Advisory UI
* Highlighting
* Merchant-controlled execution

**Additional capabilities:** Some environments may support deeper control over payment method ordering and presentation.

## Compliance and Data Handling

Pillar8 operates outside payment processing and does not require access to sensitive payment credentials.

<Callout icon="shield" color="#22C55E">
  **No cardholder data** (PAN, CVV) required for decisioning\
  **No payment credentials** stored or processed by Pillar8\
  **Outside PCI scope** — decisioning layer operates independently\
  **Standard data protection** practices supported
</Callout>

Pillar8 processes only checkout-level and transactional metadata needed for optimization. Merchants retain full control of payment processing and compliance obligations.

## Risk Profile

Pillar8 is designed to be lightweight and low-risk:

* Minimal integration effort
* No changes to payment infrastructure
* No processor replacement dependency
* No PCI scope expansion for decisioning