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PAYREX POS
Developer Documentation

Payrex Platform Docs

Learn how to integrate Payrex POS into your retail environment, manage inventory via API, and extend functionality with plugins.

Introduction

PAYREX is a unified Point of Sale operating system designed for high-volume retail environments. Unlike traditional cloud-based POS systems that rely heavily on consistent internet connectivity, Payrex uses a Local-First architecture.

This ensures zero downtime during sales, instant search results for inventory, and complete data ownership. Synchronization with the cloud happens asynchronously in the background.

Performance Note

Payrex is optimized to handle inventories of up to 1,000,000 SKUs with sub-50ms search latency on standard hardware.

Installation

Payrex POS is distributed via the Soltrix Cloud CDN. For enterprise deployments, we provide native installers for Windows (.msi) and macOS (.dmg), along with a headless setup script for Linux-based kiosks.

Note: Native installation requires a valid Enterprise License Key. If you do not have a key, please contact Soltrix Sales for a trial evaluation.

Linux / macOS (Headless)

# Install via Soltrix Package Registry

bash
curl -sL https://pkg.soltrixstudios.com/payrex/install.sh | sudo bash -s -- --key YOUR_LICENSE_KEY

Windows PowerShell

# Verify certificate and execute

powershell
irm https://pkg.soltrixstudios.com/payrex/install.ps1 | iex

Architecture

The system consists of three main components:

  • The Core: A Rust-based engine that handles hardware I/O (scanners, printers) and the local SQLite database.
  • The Interface: A high-performance React frontend optimized for touchscreens.
  • The Sync Agent: A background process that ensures eventual consistency with the Payrex Cloud.

API Reference

Payrex POS exposes a local REST API (defaulting to port 8080) allowing for tight integration with custom web-dashboards, loyalty tablets, or automated inventory scripts.

Create Transaction

POST /v1/transactions

json
{
  "transaction_id": "tx_998271",
  "clerk_id": "EMP-04",
  "items": [
    { "sku": "SOL-TSHIRT-L", "price": 25.00, "qty": 1 },
    { "sku": "SOL-STKR-PK", "price": 5.50, "qty": 2 }
  ],
  "tax_rate": 0.08,
  "payment": { "method": "STRIPE_TERMINAL", "status": "PENDING" }
}

Inventory Query

GET /v1/inventory/:sku

json
{
  "sku": "SOL-TSHIRT-L",
  "name": "Soltrix Studios Signature Tee",
  "stock_level": 42,
  "last_synced": "2026-05-01T12:00:00Z"
}

Hardware Integration

Payrex utilizes a Native Driver Bridge written in Rust to interface directly with industry-standard peripherals via USB, Serial, and Network.

Thermal Printers

Native support for ESC/POS protocols. Optimized for Star Micronics and Epson TM-series.

Barcode Scanners

High-speed HID and Serial input mapping with customizable regex prefixes.

Security & Compliance

Payrex is built for enterprise security. We implement End-to-End Encryption (E2EE) for all cloud sync traffic and full RBAC for local terminal access.

  • Argon2id Hashing: All local clerk pins are hashed using state-of-the-art cryptographic functions.
  • PCI-DSS Ready: We never store raw credit card data. All payments are handled via encrypted hardware tokens.
  • Audit Logs: Every transaction and price override is cryptographically signed and immutable.