Subscription

Subscriptions and in-app purchases through RevenueCat, behind a small async API.

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Overview

An app talks to one protocol, SubscriptionUseCase, instead of the store's own types. It covers what a paywall needs: read the entitlement, list the products, buy one, and keep the answer current as renewals and expiries arrive.

• Entitlements that survive a launch, so a cold start with no network does not turn a paying customer into a free one
• Local and authoritative entitlement reads, kept deliberately separate, and told apart in the value itself rather than by convention
• Purchase, restore, and sign-in flows
• An AsyncStream of entitlement changes, including ones the app did not cause
• A separate SubscriptionUI product with a paywall skeleton that keeps the billed amount the most prominent price on screen
• Sendable throughout, with an actor holding the state

Usage

import Subscription

let useCase = SubscriptionUseCaseImpl(
    configuration: SubscriptionConfiguration(apiKey: apiKey, entitlementId: "premium"),
    entitlementCache: FileEntitlementCache(url: entitlementFileURL)
)

if try await useCase.checkSubscriptionStatus().isActive {
    unlockPremium()
}

checkSubscriptionStatus() asks the store and is the read to trust when it decides whether someone keeps access. getSubscriptionStatus() is the instant counterpart, answering from what the device already knows.

That knowledge outlives the process. Every reading the store confirms is written to the EntitlementCache you supply, and a launch that cannot reach the store starts from it rather than from "not subscribed" — honoured for gracePeriod past the expiration date, and reported as .lastKnown(at:) so the caller can tell it apart from an answer the store just gave.

switch status.verification {
case .confirmed:            break   // The store answered in this launch.
case .lastKnown(let date):  break   // Running on what it said at `date`.
case .unverified:           break   // Nothing known yet — not the same as not subscribed.
}

There is no default cache, because the place belongs to the app: a file, an app group's UserDefaults, or the keychain. InMemoryEntitlementCache opts out, at the cost the first bullet describes.

Paywall

SubscriptionUI is a separate product carrying the parts of a paywall that are the same in every app. It depends on no design system and chooses no colour, typeface or background.

import SubscriptionUI

PaywallView(
    pages: [PaywallPage(id: "unlock") { UnlockArtwork() }],
    links: PaywallLegalLinks(terms: termsURL, privacy: privacyURL),
    onEntitled: { dismiss() }
)

It loads the current offering, puts the annual plan first and preselects it, pages through whatever pages you give it, and carries the restore button and the two legal links. The price that will be billed is the largest text in every plan row and there is no parameter that can change that, which is App Store Review 3.1.2(c) enforced by construction rather than by documentation.

Documentation

API documentation and Getting Started

The Getting Started guide covers the App Store Connect and RevenueCat dashboard setup that has to be in place first, choosing where the entitlement is kept, building a paywall, and what cannot be tested on a simulator.

Requirements

• iOS 17.0+ / macOS 14.0+
• Swift 6.0+
• RevenueCat SDK 5.14.0+

Installation

Add the package to your Package.swift:

dependencies: [
    .package(url: "https://github.com/no-problem-dev/swift-subscription.git", from: "2.0.0")
]

Or in Xcode, File > Add Package Dependencies... with https://github.com/no-problem-dev/swift-subscription.

License

MIT