Namespace VpnHood.AppLib.Abstractions.Billing

Classes

AppBilling

The in-app purchase capability of an account provider. Purchasing always needs both sides: the store that collects the payment and the backend that reconciles the order and delivers access. Which products the store is asked to price is the backend's answer too — GetProductIds(CancellationToken).

BillingException

A store billing failure in store-agnostic vocabulary. Every IBillingProvider translates its store's own errors into a BillingErrorCode here, so nothing above the provider — the app, the client API, the UI — ever learns which store failed or how that store spells its errors. Data carries the code and the store's own message across the client API (the UI reads Data["BillingErrorCode"] / Data["StoreMessage"]).

PurchaseAttribution

What the store must be told before it takes a payment, so the order comes back tied to its buyer — and so a store token stolen from one device cannot be redeemed into another account.

A type rather than a bare string because it is what IOrderProcessor answers and what IBillingProvider is then handed: on neither side is there a parameter or property name to say which of a purchase's several ids is meant, so the type says it.

PurchaseParams

What the buyer chose. Everything the app attaches on the buyer's behalf travels beside it, in PurchaseAttribution, so this carries nothing the caller is not entitled to set.

PurchaseProof

The store's own evidence that a purchase happened — a Play purchase token, an App Store signed transaction (JWS). A pointer, not a claim: the backend presents it back to the store's API and believes the store's answer, never this string.

A type rather than a bare string because it is what IBillingProvider answers, and a return value has no parameter name to say which of a purchase's several strings is meant. The order id is the tempting wrong one, and it fails at the backend rather than here.

StoreIds

Well-known store ids — the billing counterpart of AuthProviders, and the same kind of contract: a free-form lowercase STRING self-declared by the app's IBillingProvider, deliberately not an enum, so a third-party store can introduce its own id without a change to this library.

The id is consumed verbatim by the account backend: it selects which app row a purchase belongs to, which store API re-verifies the proof, and which subscriptions this device may manage. Changing one is a breaking change on the wire.

SubscriptionPlan

Represents a subscription's plan as the store prices it, in the currency the store quotes.

Interfaces

IBillingProvider

The calls that take the window get null where none is open, as in the desktop service: a store whose sheet needs one fails then, and the web store, whose checkout the UI opens, needs none.

IOrderProcessor

Backend-specific purchase reconciliation. The billing provider talks to the platform store; the order processor talks to the account backend before and after the store purchase.

Enums

BillingErrorCode

The store-agnostic vocabulary for billing failures. Providers translate their store's own error codes into these; the UI branches on nothing finer. Anything a store can say that has no user-meaningful bucket here is Unknown — the store's own message still travels with the exception for display and logs, it just never becomes a branch.

PurchaseState

Specifies where the store's payment flow stands.