Rork Max でつくるカスタムAIキーボード拡張機能：iOS Keyboard Extension 実装ガイド

import UIKit
 
class KeyboardViewController: UIInputViewController {
    
    private var hostingController: UIHostingController<KeyboardView>?
    
    // App Groupsから設定を読み込む
    private let sharedDefaults = UserDefaults(
        suiteName: "group.com.yourcompany.aikeyboard"
    )
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupKeyboardView()
    }
    
    private func setupKeyboardView() {
        let keyboardView = KeyboardView(
            hasFullAccess: hasFullAccess,
            onTextInsert: { [weak self] text in
                // テキストを現在のテキストフィールドに挿入
                self?.textDocumentProxy.insertText(text)
            },
            onTextDelete: { [weak self] in
                self?.textDocumentProxy.deleteBackward()
            },
            onNextKeyboard: { [weak self] in
                self?.advanceToNextInputMode()
            },
            onAIRequest: { [weak self] prompt, completion in
                self?.requestAICompletion(prompt: prompt, completion: completion)
            }
        )
        
        let hosting = UIHostingController(rootView: keyboardView)
        addChild(hosting)
        view.addSubview(hosting.view)
        hosting.view.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            hosting.view.topAnchor.constraint(equalTo: view.topAnchor),
            hosting.view.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            hosting.view.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            hosting.view.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])
        hosting.didMove(toParent: self)
        hostingController = hosting
    }
    
    // MARK: - AI補完リクエスト
    private func requestAICompletion(prompt: String, completion: @escaping (String) -> Void) {
        guard hasFullAccess else {
            completion("フルアクセスが必要です")
            return
        }
        
        guard let apiKey = sharedDefaults?.string(forKey: "claude_api_key"),
              \!apiKey.isEmpty else {
            completion("APIキーが設定されていません")
            return
        }
        
        Task {
            do {
                let result = try await AIService.complete(prompt: prompt, apiKey: apiKey)
                await MainActor.run { completion(result) }
            } catch {
                await MainActor.run { completion("エラーが発生しました") }
            }
        }
    }
}

import SwiftUI
 
struct KeyboardView: View {
    let hasFullAccess: Bool
    let onTextInsert: (String) -> Void
    let onTextDelete: () -> Void
    let onNextKeyboard: () -> Void
    let onAIRequest: (String, @escaping (String) -> Void) -> Void
    
    @State private var suggestions: [String] = []
    @State private var currentInput: String = ""
    @State private var isLoadingAI: Bool = false
    @State private var selectedLayout: KeyboardLayout = .qwerty
    
    var body: some View {
        VStack(spacing: 0) {
            // AIサジェストバー
            SuggestionBar(
                suggestions: suggestions,
                isLoading: isLoadingAI,
                hasFullAccess: hasFullAccess,
                onSelect: { suggestion in
                    onTextInsert(suggestion)
                    suggestions = []
                    currentInput = ""
                }
            )
            
            // キー配列
            KeyGrid(
                layout: selectedLayout,
                onKeyTap: { key in
                    handleKeyTap(key)
                }
            )
            
            // ツールバー
            KeyboardToolbar(
                hasFullAccess: hasFullAccess,
                onNextKeyboard: onNextKeyboard,
                onDelete: onTextDelete,
                onReturn: { onTextInsert("\n") }
            )
        }
        .background(Color(UIColor.systemGroupedBackground))
    }
    
    private func handleKeyTap(_ key: KeyType) {
        switch key {
        case .character(let char):
            onTextInsert(char)
            currentInput += char
            // 3文字以上入力されたらAI補完をリクエスト
            if currentInput.count >= 3 && hasFullAccess {
                fetchAISuggestions()
            }
        case .delete:
            onTextDelete()
            if \!currentInput.isEmpty {
                currentInput.removeLast()
            }
        case .return:
            onTextInsert("\n")
            currentInput = ""
            suggestions = []
        case .space:
            onTextInsert(" ")
            currentInput = ""
            suggestions = []
        }
    }
    
    private func fetchAISuggestions() {
        guard \!isLoadingAI else { return }
        isLoadingAI = true
        
        onAIRequest(currentInput) { result in
            // 結果を改行で分割して最大3件
            let items = result.components(separatedBy: "\n")
                .map { $0.trimmingCharacters(in: .whitespaces) }
                .filter { \!$0.isEmpty }
                .prefix(3)
            suggestions = Array(items)
            isLoadingAI = false
        }
    }
}

import Foundation
 
struct AIService {
    
    static func complete(prompt: String, apiKey: String) async throws -> String {
        let endpoint = URL(string: "https://api.anthropic.com/v1/messages")\!
        
        var request = URLRequest(url: endpoint)
        request.httpMethod = "POST"
        request.timeoutInterval = 8  // キーボードは応答性が最優先
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue(apiKey, forHTTPHeaderField: "x-api-key")
        request.setValue("2023-06-01", forHTTPHeaderField: "anthropic-version")
        
        let systemPrompt = """
        あなたはiOSキーボードの文章補完AIです。
        ユーザーが入力している文章の続きを3つ提案してください。
        ルール:
        - 各提案は1行で、改行で区切る
        - 自然な日本語で補完する
        - 元の文章を含めず、続きのみを提案する
        - それぞれの提案は20文字以内
        """
        
        let body: [String: Any] = [
            "model": "claude-haiku-4-5-20251001",  // 軽量・高速モデルを使用
            "max_tokens": 100,
            "system": systemPrompt,
            "messages": [
                ["role": "user", "content": "入力中のテキスト: \(prompt)"]
            ]
        ]
        
        request.httpBody = try JSONSerialization.data(withJSONObject: body)
        
        let (data, response) = try await URLSession.shared.data(for: request)
        
        guard let httpResponse = response as? HTTPURLResponse,
              (200...299).contains(httpResponse.statusCode) else {
            throw AIError.invalidResponse
        }
        
        guard let json = try JSONSerialization.jsonObject(with: data) as? [String: Any],
              let content = json["content"] as? [[String: Any]],
              let firstContent = content.first,
              let text = firstContent["text"] as? String else {
            throw AIError.parsingFailed
        }
        
        return text
    }
    
    enum AIError: Error, LocalizedError {
        case invalidResponse
        case parsingFailed
        case networkUnavailable
        
        var errorDescription: String? {
            switch self {
            case .invalidResponse: return "APIからの応答が無効です"
            case .parsingFailed: return "レスポンスの解析に失敗しました"
            case .networkUnavailable: return "ネットワークに接続できません"
            }
        }
    }
}

// SharedUserDefaults.swift — 両ターゲットで共有するユーティリティ
 
struct SharedUserDefaults {
    static let groupID = "group.com.yourcompany.aikeyboard"
    
    private static var defaults: UserDefaults {
        guard let defaults = UserDefaults(suiteName: groupID) else {
            fatalError("App Groupsが設定されていません。XcodeのCapabilitiesを確認してください。")
        }
        return defaults
    }
    
    // MARK: - APIキーの保存・取得
    // 注意: 本番環境では Keychain を使用すること
    static var claudeAPIKey: String {
        get { defaults.string(forKey: "claude_api_key") ?? "" }
        set { defaults.set(newValue, forKey: "claude_api_key") }
    }
    
    // MARK: - ユーザー設定
    static var aiEnabled: Bool {
        get { defaults.bool(forKey: "ai_enabled") }
        set { defaults.set(newValue, forKey: "ai_enabled") }
    }
    
    static var preferredLanguage: String {
        get { defaults.string(forKey: "preferred_language") ?? "ja" }
        set { defaults.set(newValue, forKey: "preferred_language") }
    }
    
    static var customTemplates: [String] {
        get { defaults.stringArray(forKey: "custom_templates") ?? [] }
        set { defaults.set(newValue, forKey: "custom_templates") }
    }
    
    // MARK: - サブスクリプション状態
    static var isPremiumActive: Bool {
        get { defaults.bool(forKey: "is_premium_active") }
        set { defaults.set(newValue, forKey: "is_premium_active") }
    }
}

import RevenueCat
 
// AppDelegate または App.init() で初期化
func setupRevenueCat() {
    Purchases.configure(withAPIKey: "YOUR_REVENUECAT_API_KEY")
    
    // サブスクリプション状態をApp Groupsに同期
    Purchases.shared.getCustomerInfo { (customerInfo, error) in
        if let error = error {
            print("RevenueCat エラー: \(error.localizedDescription)")
            return
        }
        
        let isPremium = customerInfo?.entitlements["premium"]?.isActive == true
        SharedUserDefaults.isPremiumActive = isPremium
    }
}