Overview

Welcome to the Payment Gateway documentation. The Payment Gateway is a self-hosted platform for accepting online payments, managing invoices, and configuring tax-related workflows under your own infrastructure and brand.

One of the main strategic advantages of the platform is continuity. Your payment history, invoice records, and buyer-facing billing data stay in your own system even when payment provider terms, risk decisions, or commercial models change.

Core Capabilities

• Multi-provider payments: Accept cards, wallets, local payment methods, direct debits, and transfer-based flows through a unified interface, including Stripe, Mollie, GoCardless, Wise, PayPal, and wire transfer.
• Payment data boundary: In the intended provider-hosted or tokenized card flow, the gateway is designed not to store raw PAN/CVC values.
• Persistent history and invoicing: Keep one payment and invoice history across provider changes, with gapless numbering, PDF invoice customization, and configured ZUGFeRD/Factur-X, Peppol BIS 3.0 XML, and XRechnung outputs. Finalized buyer documents are downloaded through the customer portal.
• Multi-tenant organizations: Full role-based access control for teams with a dedicated Admin Panel.
• Configurable tax engine: Effective-dated tax rates, tax rules, VAT ID validation, EU VAT OSS reporting, tax snapshots, and canonical tax records for reporting and auditability.
• Customer portal: A branded, self-service portal for buyers to access invoices, preview upcoming recurring charges, and manage subscription cancellation on your configured hosted portal domain or your own mapped portal domain.

Portal Experience

The buyer-facing customer portal is deployment-specific. Product documentation uses first-party domains only as examples; self-hosted customers can map their own domains and branding.

Application hostnames on the hosted stack (dashboard, api, secure, webhook under payment-gateway.app) are summarized in Hostnames & DNS conventions.

Operations

• Flexible deployment: Docker Compose or rootless Podman on Linux, with automated upgrade tooling.
• License activation: Self-hosted installations activate with a license key and periodically synchronize signed entitlement state. Runtime enforcement uses the local signed state described in the deployment guide.
• Data lifecycle controls: Organization-level retention settings plus GDPR-oriented backup and restore runbooks.

Commercial Model

• One implementation: Integrate once against your own gateway surface and keep providers replaceable behind it.
• Custom provider additions: Additional payment providers can be added for 100 EUR one-time per provider.
• Invoice output flexibility: PDF invoice customization and related billing adjustments are available for teams that need tailored output.

Getting Started

• Hostnames & DNS conventions - Hosted *.payment-gateway.app layout and deployment hostname variables.
• Self-Hosted Installation - Install the stack with Docker Compose, required domains, activation, and updates.
• Quick Start - Set up your first hosted checkout flow.
• Server integration checklist - Hostnames, webhooks, Admin API, IPN.
• Integration Recipes - Practical checkout, webhook, IPN, reconciliation, and tax export flows.
• Features & User Guide - How to use the platform as a merchant.
• Customer Portal - Buyer document access, payment links, and recurring cancellation.
• Recurring Schedules - Subscription invoice generation, review, and auto-issue behavior.
• Tax Configuration Examples - Scenario-based VAT, OSS, reverse-charge, and gross/net pricing setup.
• API Reference - REST API documentation for programmatic integration.
• Payment Data Boundary - Payment-data handling assumptions and operational evidence.
• Licensing Operations - Runtime license states, activation, support-window sync, and recovery actions.
• Architecture & Components - How the system fits together technically.
• Deployment - Self-hosting installation guide.