Glossary

Admin Backend

The authenticated management API used by operators and merchant server-side integrations. It owns organizations, sites, providers, API keys, checkout creation, settings, invoices, reports, and administrative workflows.

Admin Frontend

The browser-based Admin Panel used by operators to configure the gateway and review payments, invoices, clients, settings, reports, and licensing state.

API Key

A bearer credential used by trusted server-side integrations. Organization API keys are scoped to one organization. System API keys are for global administrative automation.

Checkout

A temporary hosted payment session created by the Admin API or Admin Panel. Buyers open the checkout URL on the Main Frontend and complete payment through a provider-backed flow.

Client

The gateway's customer record for a billed party. Clients can be created manually, imported, or inferred from completed checkout and invoice activity.

Credit Note

A legal reversal document that offsets an issued invoice. Credit notes do not mutate the original invoice; they create a separate accounting and tax trail.

External Reference

The merchant-provided order or business identifier attached to checkout and transaction records. Use it to reconcile gateway records with your own system.

IPN

Instant Payment Notification. This is the outbound signed notification sent from the gateway to your application when transaction status changes. It is separate from provider webhooks.

Main Backend

The buyer-facing and provider-facing runtime API. It serves checkout sessions, transaction submission, customer portal APIs, VAT validation, and provider webhook endpoints.

Main Frontend

The buyer-facing hosted checkout and customer portal UI.

Organization

The top-level tenant boundary. Users, sites, providers, API keys, clients, transactions, invoices, and tax settings are scoped to an organization unless explicitly documented otherwise.

Provider

An upstream payment processor or payment method integration, such as Stripe, Mollie, GoCardless, Wise, PayPal, or manual wire transfer.

Provider Webhook

An inbound webhook sent by a payment provider to the Main Backend. Provider webhooks update gateway transaction state and should be configured on the Main Backend host.

Site

A checkout surface within an organization. Sites group branding, provider availability, checkout behavior, custom domains, and webhook signing secrets.

Tax Decision

The persisted explanation of how tax was resolved for a transaction or document. It can include treatment, rule metadata, seller country, buyer country, buyer type, VIES validation metadata, and evidence confidence.

Tax Record

An immutable canonical tax ledger record used by tax reports and exports. Tax records are written for material tax events such as transactions, invoices, credit notes, refunds, and chargebacks.

VAT OSS

EU VAT One Stop Shop. In the gateway, OSS reports aggregate canonical tax records for eligible EU B2C cross-border sales, including refund and chargeback adjustments.

Webhook Signing Secret

The Site-level secret used to sign outbound IPN payloads. Provider webhook secrets are configured separately on provider records.