iOS でサブスクリプションを管理非公開プレビュー

import 'dotenv/config';
import express from 'express';
import Stripe from 'stripe';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY || '', {
  apiVersion: '2025-07-30.basil',
});

const app = express();
app.use(express.json());

app.post('/authenticate', async (req, res) => {
  try {
    // Replace with your auth; return 401 if the user is not logged in
    const user = authUser(req);
    if (!user) {
      res.status(401).json({ error: { type: 'no_session_present' } });
      return;
    }

    const customerSession = await stripe.customerSessions.create({
      customer: user.stripeCustomerId,
      components: {
        buy_button: { enabled: true },
        active_entitlements: { enabled: true },
        customer_portal: { enabled: true },
      } as any,
    });

    res.json({
      clientSecret: customerSession.client_secret,
      expiresAt: customerSession.expires_at,
      customer: customerSession.customer as string,
    });
  } catch (err) {
    res.status(500).json({ error: { message: 'Internal server error' } });
  }
});

app.listen(3000);

import Foundation
import BillingSDK
import SwiftUI

class BillingManager {
    static let shared = BillingManager()

    public let billing: BillingSDK

    private init() {
        // Initialize with your publishable key and set how long entitlements can be stale before needing to refresh.
        let configuration = BillingSDK.Configuration(
          publishableKey: "pk_test_…",
          maximumStaleEntitlementsDuration: TimeInterval(60 * 5)
        )
        self.billing = BillingSDK(configuration: configuration)

        // Set up authentication (see below for implementation)
        setupCustomerSessionProvider()

        // Add entitlement change listener (see below for implementation)
        setupEntitlementListener()
    }
}

import Foundation
import BillingSDK

extension BillingManager {
    func setupCustomerSessionProvider() {
        billing.setCustomerSessionProvider { [weak self] in
            await self?.fetchCustomerSession()
        }
    }

    private func fetchCustomerSession() async -> UBCustomerSessionDetails? {
        // Configure request to your backend endpoint
        guard let url = URL(string: "https://your-backend.example.com/customer-session") else {
            print("Invalid URL")
            return nil
        }

        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")

        // Send any additional headers needed to authenticate the user, for example, an auth token.
        request.setValue("Bearer \(authToken)", forHTTPHeaderField: "Authorization")

        do {
            // Make the request
            let (data, response) = try await URLSession.shared.data(for: request)

            guard let httpResponse = response as? HTTPURLResponse else {
                print("Invalid response format")
                return nil
            }

            switch httpResponse.statusCode {
            case 200:
                // Parse the successful response
                let decoder = JSONDecoder()
                decoder.dateDecodingStrategy = .secondsSince1970
                return try decoder.decode(UBCustomerSessionDetails.self, from: data)

            case 401:
                // User not authenticated - SDK will enter unauthenticated state
                print("Authentication required")
                return nil

            default:
                print("Unexpected status code: \(httpResponse.statusCode)")
                return nil
            }
        } catch {
            print("Session provider error: \(error.localizedDescription)")
            return nil
        }
    }

    // Call this method when your user signs out
    func handleSignOut() async {
        await billing.reset() // Clear session data and caches
    }
}

import SwiftUI
import BillingSDK

struct SubscriptionView: View {
    @State private var buyButton: BuyButton?
    @State private var isLoading = true
    @State private var errorMessage: String?

    // Replace with your buy button ID from the Dashboard
    let buttonId = "buy_btn_1Abcdef123456"

    var body: some View {
        VStack {
            if isLoading {
                ProgressView("Loading subscription options...")
            } else if let buyButton = buyButton {
                // Display the prebuilt buy button UI
                // Alternatively the BuyButton class also provides all the data to render
                // a custom UI element.
                buyButton.view()
                    .frame(height: 56)
                    .padding(.horizontal)
            } else if let errorMessage = errorMessage {
                Text("Error: \(errorMessage)")
                    .foregroundColor(.red)
                Button("Retry") {
                    loadBuyButton()
                }
            }
        }
        .onAppear {
            loadBuyButton()
        }
    }

    func loadBuyButton() {
        isLoading = true
        errorMessage = nil

        Task {
            do {
                // Fetch the button from Stripe
                buyButton = try await BillingManager.shared.billing.getBuyButton(id: buttonId)
                isLoading = false
            } catch {
                errorMessage = "Failed to load buy button"
                isLoading = false
            }
        }
    }
}

func checkPremiumAccess() async {
    do {
        let hasPremiumAccess = try await BillingManager.shared.billing.hasEntitlement(lookupKey: "premium_tier")

        if hasPremiumAccess {
            // User has premium access - enable features
            unlockPremiumFeatures()
        } else {
            // User doesn't have access - show upsell
            showPremiumUpsell()
        }
    } catch {
        showErrorMessage("Couldn't verify entitlements status")
    }
}

func loadUserEntitlements() async {
    do {
        // Force refresh ensures we get the latest data from the server
        let entitlements = try await BillingManager.shared.billing.getActiveEntitlements(forceRefresh: true)

        // Map entitlements to app features
        let features = entitlements.map { $0.lookupKey }
        updateAvailableFeatures(features)

    } catch {
        handleError(error)
    }
}

import Foundation
import BillingSDK

extension BillingManager {
    func setupEntitlementListener() {
        billing.onEntitlementsChanged { updatedEntitlements in
            // Update UI based on new entitlements
            DispatchQueue.main.async {
                self.updateAppFeatures(based: updatedEntitlements)
                self.refreshUI()
            }
        }
    }
}

func manageSubscriptionTapped() {
    Task {
        do {
            let portal = try await BillingManager.shared.billing.getCustomerPortal()

            // Show portal within your app (recommended)
            portal.presentCustomerPortal(from: self)

        } catch {
            if let billingError = error as? BillingSDKError {
                switch billingError {
                case .unauthenticated:
                    // User needs to log in first
                    showLoginPrompt()
                default:
                    // Handle other errors
                    showErrorMessage("Could not load subscription management")
                }
            } else {
                showErrorMessage("Could not load subscription management")
            }
        }
    }
}

let portal = try await BillingManager.shared.billing.getCustomerPortal()
portal.redirectToCustomerPortal() // Opens in default browser

func signOut() async {
    // Clear your app's auth state
    UserDefaults.standard.removeObject(forKey: "auth_token")

    // Reset the BillingSDK state
    await BillingManager.shared.billing.reset()

    // Navigate to login screen
    showLoginScreen()
}