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Swift Examples

Complete, production-ready code examples for integrating Kixago API in Swift applications. Perfect for iOS/macOS apps and backend services! 🍎

Quick Start​

Installation (Swift Package Manager)​

// Package.swift
// swift-tools-version:5.9
import PackageDescription

let package = Package(
    name: "KixagoExample",
    platforms: [
        .iOS(.v15),
        .macOS(.v12)
    ],
    dependencies: [
        // No external dependencies needed for basic usage!
        // Optional: For advanced features
        .package(url: "https://github.com/apple/swift-log.git", from: "1.5.0"),
    ],
    targets: [
        .executableTarget(
            name: "KixagoExample",
            dependencies: [
                .product(name: "Logging", package: "swift-log"),
            ]
        )
    ]
)

Basic Examples​

Example 1: Simple Request (iOS/macOS)​

import Foundation

struct DeFiScore: Codable {
    let defiScore: Int
    let riskLevel: String
    let riskCategory: String
    
    enum CodingKeys: String, CodingKey {
        case defiScore = "defi_score"
        case riskLevel = "risk_level"
        case riskCategory = "risk_category"
    }
}

struct RiskProfile: Codable {
    let walletAddress: String
    let totalCollateralUsd: Double
    let totalBorrowedUsd: Double
    let globalHealthFactor: Double
    let globalLtv: Double
    let defiScore: DeFiScore?
    
    enum CodingKeys: String, CodingKey {
        case walletAddress = "wallet_address"
        case totalCollateralUsd = "total_collateral_usd"
        case totalBorrowedUsd = "total_borrowed_usd"
        case globalHealthFactor = "global_health_factor"
        case globalLtv = "global_ltv"
        case defiScore = "defi_score"
    }
}

// Simple async/await example
func getRiskProfile(walletAddress: String, apiKey: String) async throws -> RiskProfile {
    let url = URL(string: "https://api.kixago.com/v1/risk-profile/\(walletAddress)")!
    
    var request = URLRequest(url: url)
    request.setValue(apiKey, forHTTPHeaderField: "X-API-Key")
    request.setValue("application/json", forHTTPHeaderField: "Accept")
    request.timeoutInterval = 30
    
    let (data, response) = try await URLSession.shared.data(for: request)
    
    guard let httpResponse = response as? HTTPURLResponse,
          httpResponse.statusCode == 200 else {
        throw URLError(.badServerResponse)
    }
    
    let profile = try JSONDecoder().decode(RiskProfile.self, from: data)
    return profile
}

// Usage in SwiftUI
import SwiftUI

struct ContentView: View {
    @State private var profile: RiskProfile?
    @State private var isLoading = false
    
    var body: some View {
        VStack {
            if isLoading {
                ProgressView("Loading...")
            } else if let profile = profile {
                Text("DeFi Score: \(profile.defiScore?.defiScore ?? 0)")
                Text("Risk Level: \(profile.defiScore?.riskLevel ?? "N/A")")
                Text("Health Factor: \(String(format: "%.2f", profile.globalHealthFactor))")
            } else {
                Button("Load Profile") {
                    Task {
                        isLoading = true
                        defer { isLoading = false }
                        
                        do {
                            profile = try await getRiskProfile(
                                walletAddress: "0xf0bb20865277aBd641a307eCe5Ee04E79073416C",
                                apiKey: ProcessInfo.processInfo.environment["KIXAGO_API_KEY"] ?? ""
                            )
                        } catch {
                            print("Error: \(error)")
                        }
                    }
                }
            }
        }
        .padding()
    }
}

Example 2: Complete Type Definitions​

// Models.swift
import Foundation

struct TokenDetail: Codable {
    let token: String
    let amount: Double
    let usdValue: Double
    let tokenAddress: String
    
    enum CodingKeys: String, CodingKey {
        case token
        case amount
        case usdValue = "usd_value"
        case tokenAddress = "token_address"
    }
}

struct LendingPosition: Codable {
    let `protocol`: String
    let protocolVersion: String
    let chain: String
    let userAddress: String
    let collateralUsd: Double
    let borrowedUsd: Double
    let healthFactor: Double
    let ltvCurrent: Double
    let isAtRisk: Bool
    let collateralDetails: [TokenDetail]?
    let borrowedDetails: [TokenDetail]?
    let lastUpdated: Date
    
    enum CodingKeys: String, CodingKey {
        case `protocol`
        case protocolVersion = "protocol_version"
        case chain
        case userAddress = "user_address"
        case collateralUsd = "collateral_usd"
        case borrowedUsd = "borrowed_usd"
        case healthFactor = "health_factor"
        case ltvCurrent = "ltv_current"
        case isAtRisk = "is_at_risk"
        case collateralDetails = "collateral_details"
        case borrowedDetails = "borrowed_details"
        case lastUpdated = "last_updated"
    }
}

struct ComponentScore: Codable {
    let componentScore: Double
    let weight: Double
    let weightedContribution: Double
    let reasoning: String
    
    enum CodingKeys: String, CodingKey {
        case componentScore = "component_score"
        case weight
        case weightedContribution = "weighted_contribution"
        case reasoning
    }
}

struct ScoreBreakdown: Codable {
    let healthFactorScore: ComponentScore
    let leverageScore: ComponentScore
    let diversificationScore: ComponentScore
    let volatilityScore: ComponentScore
    let protocolRiskScore: ComponentScore
    let totalInternalScore: Double
    
    enum CodingKeys: String, CodingKey {
        case healthFactorScore = "health_factor_score"
        case leverageScore = "leverage_score"
        case diversificationScore = "diversification_score"
        case volatilityScore = "volatility_score"
        case protocolRiskScore = "protocol_risk_score"
        case totalInternalScore = "total_internal_score"
    }
}

struct RiskFactor: Codable {
    let severity: String
    let factor: String
    let description: String
    let impactOnScore: Int
    
    enum CodingKeys: String, CodingKey {
        case severity
        case factor
        case description
        case impactOnScore = "impact_on_score"
    }
}

struct Recommendations: Codable {
    let immediate: [String]
    let shortTerm: [String]
    let longTerm: [String]
    
    enum CodingKeys: String, CodingKey {
        case immediate
        case shortTerm = "short_term"
        case longTerm = "long_term"
    }
}

struct LiquidationScenario: Codable {
    let event: String
    let newHealthFactor: Double
    let status: String
    let timeEstimate: String?
    let estimatedLoss: String?
    
    enum CodingKeys: String, CodingKey {
        case event
        case newHealthFactor = "new_health_factor"
        case status
        case timeEstimate = "time_estimate"
        case estimatedLoss = "estimated_loss"
    }
}

struct LiquidationSimulation: Codable {
    let currentHealthFactor: Double
    let liquidationThreshold: Double
    let bufferPercentage: Double
    let scenarios: [LiquidationScenario]
    
    enum CodingKeys: String, CodingKey {
        case currentHealthFactor = "current_health_factor"
        case liquidationThreshold = "liquidation_threshold"
        case bufferPercentage = "buffer_percentage"
        case scenarios
    }
}

struct DeFiScore: Codable {
    let defiScore: Int
    let riskLevel: String
    let riskCategory: String
    let color: String
    let scoreBreakdown: ScoreBreakdown
    let riskFactors: [RiskFactor]
    let recommendations: Recommendations
    let liquidationSimulation: LiquidationSimulation
    let calculatedAt: Date
    
    enum CodingKeys: String, CodingKey {
        case defiScore = "defi_score"
        case riskLevel = "risk_level"
        case riskCategory = "risk_category"
        case color
        case scoreBreakdown = "score_breakdown"
        case riskFactors = "risk_factors"
        case recommendations
        case liquidationSimulation = "liquidation_simulation"
        case calculatedAt = "calculated_at"
    }
}

struct RiskProfileResponse: Codable {
    let walletAddress: String
    let totalCollateralUsd: Double
    let totalBorrowedUsd: Double
    let globalHealthFactor: Double
    let globalLtv: Double
    let positionsAtRiskCount: Int
    let lastUpdated: Date
    let aggregationDuration: String
    let lendingPositions: [LendingPosition]
    let defiScore: DeFiScore?
    let aggregationErrors: [String: String]?
    
    enum CodingKeys: String, CodingKey {
        case walletAddress = "wallet_address"
        case totalCollateralUsd = "total_collateral_usd"
        case totalBorrowedUsd = "total_borrowed_usd"
        case globalHealthFactor = "global_health_factor"
        case globalLtv = "global_ltv"
        case positionsAtRiskCount = "positions_at_risk_count"
        case lastUpdated = "last_updated"
        case aggregationDuration = "aggregation_duration"
        case lendingPositions = "lending_positions"
        case defiScore = "defi_score"
        case aggregationErrors = "aggregation_errors"
    }
}

// Helper extensions
extension RiskProfileResponse {
    /// Check if any positions are at risk
    var hasPositionsAtRisk: Bool {
        positionsAtRiskCount > 0
    }
    
    /// Get positions for a specific chain
    func positions(forChain chain: String) -> [LendingPosition] {
        lendingPositions.filter { $0.chain == chain }
    }
    
    /// Get total collateral for a specific protocol
    func collateral(forProtocol protocol: String) -> Double {
        lendingPositions
            .filter { $0.protocol == `protocol` }
            .reduce(0) { $0 + $1.collateralUsd }
    }
}

Example 3: Type-Safe Client with Error Handling​

// KixagoError.swift
import Foundation

enum KixagoError: LocalizedError {
    case invalidAddress(String)
    case unauthorized
    case rateLimited(retryAfter: Int)
    case serverError(String)
    case apiError(status: Int, message: String)
    case networkError(Error)
    case decodingError(Error)
    
    var errorDescription: String? {
        switch self {
        case .invalidAddress(let addr):
            return "Invalid wallet address: \(addr)"
        case .unauthorized:
            return "Invalid API key"
        case .rateLimited(let seconds):
            return "Rate limit exceeded - retry after \(seconds)s"
        case .serverError(let msg):
            return "Server error: \(msg)"
        case .apiError(let status, let msg):
            return "API error \(status): \(msg)"
        case .networkError(let error):
            return "Network error: \(error.localizedDescription)"
        case .decodingError(let error):
            return "Failed to decode response: \(error.localizedDescription)"
        }
    }
}

// KixagoClient.swift
import Foundation
import os.log

actor KixagoClient {
    private let apiKey: String
    private let baseURL: URL
    private let session: URLSession
    private let logger = Logger(subsystem: "com.kixago", category: "api")
    
    private lazy var decoder: JSONDecoder = {
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        return decoder
    }()
    
    init(apiKey: String, baseURL: String = "https://api.kixago.com") {
        self.apiKey = apiKey
        self.baseURL = URL(string: baseURL)!
        
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 30
        config.timeoutIntervalForResource = 60
        self.session = URLSession(configuration: config)
    }
    
    /// Get risk profile for a wallet address
    func getRiskProfile(walletAddress: String) async throws -> RiskProfileResponse {
        guard !walletAddress.isEmpty else {
            throw KixagoError.invalidAddress("Address cannot be empty")
        }
        
        logger.info("Fetching risk profile for \(walletAddress)")
        
        let url = baseURL.appendingPathComponent("v1/risk-profile/\(walletAddress)")
        
        var request = URLRequest(url: url)
        request.setValue(apiKey, forHTTPHeaderField: "X-API-Key")
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        
        do {
            let (data, response) = try await session.data(for: request)
            
            guard let httpResponse = response as? HTTPURLResponse else {
                throw KixagoError.networkError(URLError(.badServerResponse))
            }
            
            return try await handleResponse(data: data, response: httpResponse)
            
        } catch let error as KixagoError {
            throw error
        } catch {
            throw KixagoError.networkError(error)
        }
    }
    
    private func handleResponse(
        data: Data,
        response: HTTPURLResponse
    ) async throws -> RiskProfileResponse {
        switch response.statusCode {
        case 200:
            do {
                let profile = try decoder.decode(RiskProfileResponse.self, from: data)
                
                // Warn about partial failures
                if let errors = profile.aggregationErrors, !errors.isEmpty {
                    logger.warning("⚠️ Partial failure: \(errors.keys.joined(separator: ", "))")
                }
                
                return profile
                
            } catch {
                throw KixagoError.decodingError(error)
            }
            
        case 400:
            let errorMsg = try? JSONDecoder().decode([String: String].self, from: data)
            throw KixagoError.invalidAddress(errorMsg?["error"] ?? "Invalid request")
            
        case 401:
            throw KixagoError.unauthorized
            
        case 429:
            let retryAfter = response.value(forHTTPHeaderField: "Retry-After")
                .flatMap(Int.init) ?? 5
            throw KixagoError.rateLimited(retryAfter: retryAfter)
            
        case 500:
            throw KixagoError.serverError("Internal server error")
            
        default:
            let errorMsg = try? JSONDecoder().decode([String: String].self, from: data)
            throw KixagoError.apiError(
                status: response.statusCode,
                message: errorMsg?["error"] ?? "Unknown error"
            )
        }
    }
}

// Usage Example
Task {
    do {
        let client = KixagoClient(
            apiKey: ProcessInfo.processInfo.environment["KIXAGO_API_KEY"] ?? ""
        )
        
        let profile = try await client.getRiskProfile(
            walletAddress: "0xf0bb20865277aBd641a307eCe5Ee04E79073416C"
        )
        
        if let score = profile.defiScore {
            print("DeFi Score: \(score.defiScore)")
            print("Risk Level: \(score.riskLevel)")
        }
        print("Health Factor: \(String(format: "%.2f", profile.globalHealthFactor))")
        
    } catch {
        print("Error: \(error.localizedDescription)")
    }
}

Caching Implementation​

Example 4: In-Memory Cache with NSCache​

// CachedKixagoClient.swift
import Foundation

actor CachedKixagoClient {
    private let client: KixagoClient
    private let cache = NSCache<NSString, CachedProfile>()
    private let cacheTTL: TimeInterval = 30 // 30 seconds
    
    init(apiKey: String) {
        self.client = KixagoClient(apiKey: apiKey)
        
        // Configure cache limits
        cache.countLimit = 100
        cache.totalCostLimit = 50 * 1024 * 1024 // 50MB
    }
    
    func getRiskProfile(walletAddress: String) async throws -> RiskProfileResponse {
        let cacheKey = NSString(string: walletAddress)
        
        // Check cache
        if let cached = cache.object(forKey: cacheKey),
           cached.isValid {
            print("✅ Cache HIT for \(walletAddress)")
            return cached.profile
        }
        
        print("❌ Cache MISS for \(walletAddress)")
        
        // Fetch from API
        let profile = try await client.getRiskProfile(walletAddress: walletAddress)
        
        // Cache the result
        cache.setObject(
            CachedProfile(profile: profile, ttl: cacheTTL),
            forKey: cacheKey
        )
        
        return profile
    }
}

// Cache wrapper class
private class CachedProfile {
    let profile: RiskProfileResponse
    let timestamp: Date
    let ttl: TimeInterval
    
    init(profile: RiskProfileResponse, ttl: TimeInterval) {
        self.profile = profile
        self.timestamp = Date()
        self.ttl = ttl
    }
    
    var isValid: Bool {
        Date().timeIntervalSince(timestamp) < ttl
    }
}

Real-World Use Cases​

Example 5: Credit Underwriting Service​

// UnderwritingService.swift
import Foundation

enum Decision: String {
    case approved = "APPROVED"
    case declined = "DECLINED"
    case manualReview = "MANUAL_REVIEW"
}

struct UnderwritingDecision {
    let decision: Decision
    let reason: String
    let defiScore: Int?
    let riskCategory: String?
    let maxLoanAmount: Double?
    let conditions: [String]
    
    static func approved(
        reason: String,
        score: Int,
        category: String,
        maxLoan: Double
    ) -> UnderwritingDecision {
        UnderwritingDecision(
            decision: .approved,
            reason: reason,
            defiScore: score,
            riskCategory: category,
            maxLoanAmount: maxLoan,
            conditions: []
        )
    }
    
    static func declined(reason: String, score: Int?) -> UnderwritingDecision {
        UnderwritingDecision(
            decision: .declined,
            reason: reason,
            defiScore: score,
            riskCategory: nil,
            maxLoanAmount: nil,
            conditions: []
        )
    }
    
    static func manualReview(
        reason: String,
        score: Int?,
        conditions: [String]
    ) -> UnderwritingDecision {
        UnderwritingDecision(
            decision: .manualReview,
            reason: reason,
            defiScore: score,
            riskCategory: nil,
            maxLoanAmount: nil,
            conditions: conditions
        )
    }
}

actor UnderwritingService {
    private let client: KixagoClient
    
    init(client: KixagoClient) {
        self.client = client
    }
    
    func underwrite(
        walletAddress: String,
        requestedLoanAmount: Double
    ) async -> UnderwritingDecision {
        // Fetch DeFi profile
        let profile: RiskProfileResponse
        do {
            profile = try await client.getRiskProfile(walletAddress: walletAddress)
        } catch {
            return .manualReview(
                reason: "Error fetching DeFi profile - manual review required",
                score: nil,
                conditions: []
            )
        }
        
        // Check if wallet has DeFi history
        guard let defiScore = profile.defiScore else {
            return .declined(
                reason: "No DeFi lending history found",
                score: nil
            )
        }
        
        let score = defiScore.defiScore
        let riskCategory = defiScore.riskCategory
        let healthFactor = profile.globalHealthFactor
        let collateral = profile.totalCollateralUsd
        
        // Rule 1: Minimum credit score
        if score < 550 {
            return .declined(
                reason: "DeFi credit score too low: \(score)",
                score: score
            )
        }
        
        // Rule 2: Health factor requirement
        if healthFactor > 0 && healthFactor < 1.5 {
            return .declined(
                reason: String(format: "Health factor too low: %.2f (minimum 1.5)", healthFactor),
                score: score
            )
        }
        
        // Rule 3: Collateral requirement (2x loan amount)
        let minCollateral = requestedLoanAmount * 2
        if collateral < minCollateral {
            return .declined(
                reason: String(format: "Insufficient collateral. Need $%.0f, have $%.0f",
                             minCollateral, collateral),
                score: score
            )
        }
        
        // Rule 4: Risk category checks
        if riskCategory == "URGENT_ACTION_REQUIRED" {
            return .declined(
                reason: "Critical risk factors detected - imminent liquidation risk",
                score: score
            )
        }
        
        if riskCategory == "HIGH_RISK" {
            return .manualReview(
                reason: "High risk category - requires underwriter review",
                score: score,
                conditions: defiScore.recommendations.immediate
            )
        }
        
        // Calculate max loan amount (50% of collateral)
        let maxLoan = collateral * 0.5
        
        if requestedLoanAmount > maxLoan {
            return .manualReview(
                reason: "Requested amount exceeds max (50% of collateral)",
                score: score,
                conditions: []
            )
        }
        
        // APPROVED!
        return .approved(
            reason: "Strong DeFi profile - Score \(score), Risk: \(riskCategory)",
            score: score,
            category: riskCategory,
            maxLoan: maxLoan
        )
    }
}

// Usage
Task {
    let client = KixagoClient(
        apiKey: ProcessInfo.processInfo.environment["KIXAGO_API_KEY"] ?? ""
    )
    let service = UnderwritingService(client: client)
    
    let decision = await service.underwrite(
        walletAddress: "0xf0bb20865277aBd641a307eCe5Ee04E79073416C",
        requestedLoanAmount: 500_000
    )
    
    print("Decision: \(decision.decision.rawValue)")
    print("Reason: \(decision.reason)")
}

Example 6: SwiftUI Portfolio Monitoring App​

// PortfolioViewModel.swift
import SwiftUI
import Combine

@MainActor
class PortfolioViewModel: ObservableObject {
    @Published var walletAddress = ""
    @Published var profile: RiskProfileResponse?
    @Published var isLoading = false
    @Published var error: String?
    
    private let client: KixagoClient
    
    init(apiKey: String) {
        self.client = KixagoClient(apiKey: apiKey)
    }
    
    func loadProfile() async {
        isLoading = true
        error = nil
        
        defer { isLoading = false }
        
        do {
            profile = try await client.getRiskProfile(walletAddress: walletAddress)
        } catch {
            self.error = error.localizedDescription
        }
    }
}

// PortfolioView.swift
struct PortfolioView: View {
    @StateObject private var viewModel: PortfolioViewModel
    
    init(apiKey: String) {
        _viewModel = StateObject(wrappedValue: PortfolioViewModel(apiKey: apiKey))
    }
    
    var body: some View {
        NavigationView {
            VStack(spacing: 20) {
                // Wallet input
                TextField("Enter wallet address or ENS", text: $viewModel.walletAddress)
                    .textFieldStyle(.roundedBorder)
                    .autocapitalization(.none)
                    .padding()
                
                Button("Check Credit Score") {
                    Task {
                        await viewModel.loadProfile()
                    }
                }
                .buttonStyle(.borderedProminent)
                .disabled(viewModel.isLoading || viewModel.walletAddress.isEmpty)
                
                // Loading state
                if viewModel.isLoading {
                    ProgressView("Analyzing DeFi positions...")
                }
                
                // Error state
                if let error = viewModel.error {
                    Text(error)
                        .foregroundColor(.red)
                        .padding()
                }
                
                // Success state
                if let profile = viewModel.profile {
                    ProfileCard(profile: profile)
                }
                
                Spacer()
            }
            .navigationTitle("DeFi Credit Score")
        }
    }
}

struct ProfileCard: View {
    let profile: RiskProfileResponse
    
    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            // Credit Score
            if let score = profile.defiScore {
                HStack {
                    Text("\(score.defiScore)")
                        .font(.system(size: 64, weight: .bold))
                        .foregroundColor(colorForScore(score.color))
                    
                    VStack(alignment: .leading) {
                        Text(score.riskLevel)
                            .font(.headline)
                        Text(score.riskCategory)
                            .font(.caption)
                            .foregroundColor(.secondary)
                    }
                }
            }
            
            Divider()
            
            // Portfolio Stats
            HStack {
                VStack(alignment: .leading) {
                    Text("Collateral")
                        .font(.caption)
                        .foregroundColor(.secondary)
                    Text("$\(formatted(profile.totalCollateralUsd))")
                        .font(.headline)
                }
                
                Spacer()
                
                VStack(alignment: .trailing) {
                    Text("Debt")
                        .font(.caption)
                        .foregroundColor(.secondary)
                    Text("$\(formatted(profile.totalBorrowedUsd))")
                        .font(.headline)
                }
            }
            
            HStack {
                VStack(alignment: .leading) {
                    Text("Health Factor")
                        .font(.caption)
                        .foregroundColor(.secondary)
                    Text(String(format: "%.2f", profile.globalHealthFactor))
                        .font(.headline)
                        .foregroundColor(healthFactorColor(profile.globalHealthFactor))
                }
                
                Spacer()
                
                VStack(alignment: .trailing) {
                    Text("LTV")
                        .font(.caption)
                        .foregroundColor(.secondary)
                    Text(String(format: "%.1f%%", profile.globalLtv))
                        .font(.headline)
                }
            }
            
            // Recommendations
            if let recommendations = profile.defiScore?.recommendations,
               !recommendations.immediate.isEmpty {
                Divider()
                
                Text("⚠️ Immediate Actions")
                    .font(.headline)
                
                ForEach(recommendations.immediate, id: \.self) { action in
                    Text("• \(action)")
                        .font(.caption)
                        .foregroundColor(.orange)
                }
            }
        }
        .padding()
        .background(Color(.systemGray6))
        .cornerRadius(12)
        .padding()
    }
    
    private func formatted(_ value: Double) -> String {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.maximumFractionDigits = 0
        return formatter.string(from: NSNumber(value: value)) ?? "0"
    }
    
    private func colorForScore(_ colorName: String) -> Color {
        switch colorName {
        case "green": return .green
        case "blue": return .blue
        case "yellow": return .yellow
        case "orange": return .orange
        case "red": return .red
        default: return .primary
        }
    }
    
    private func healthFactorColor(_ hf: Double) -> Color {
        if hf >= 2.0 { return .green }
        if hf >= 1.5 { return .blue }
        if hf >= 1.2 { return .yellow }
        if hf >= 1.0 { return .orange }
        return .red
    }
}

Concurrent Processing​

Example 7: Batch Fetching with TaskGroup​

// BatchProcessor.swift
import Foundation

actor BatchProcessor {
    private let client: KixagoClient
    
    init(client: KixagoClient) {
        self.client = client
    }
    
    func getMultipleProfiles(
        walletAddresses: [String]
    ) async -> [String: Result<RiskProfileResponse, Error>] {
        await withTaskGroup(
            of: (String, Result<RiskProfileResponse, Error>).self
        ) { group in
            // Add tasks for each wallet
            for address in walletAddresses {
                group.addTask {
                    do {
                        let profile = try await self.client.getRiskProfile(
                            walletAddress: address
                        )
                        return (address, .success(profile))
                    } catch {
                        return (address, .failure(error))
                    }
                }
            }
            
            // Collect results
            var results: [String: Result<RiskProfileResponse, Error>] = [:]
            for await (address, result) in group {
                results[address] = result
            }
            
            return results
        }
    }
}

// Usage
Task {
    let client = KixagoClient(
        apiKey: ProcessInfo.processInfo.environment["KIXAGO_API_KEY"] ?? ""
    )
    let batch = BatchProcessor(client: client)
    
    let wallets = [
        "0xWallet1...",
        "0xWallet2...",
        "0xWallet3..."
    ]
    
    let results = await batch.getMultipleProfiles(walletAddresses: wallets)
    
    for (wallet, result) in results {
        switch result {
        case .success(let profile):
            let score = profile.defiScore?.defiScore ?? 0
            print("✅ \(wallet): Score \(score)")
        case .failure(let error):
            print("❌ \(wallet): \(error.localizedDescription)")
        }
    }
}

Testing​

Example 8: Unit Tests with XCTest​

// KixagoClientTests.swift
import XCTest
@testable import KixagoExample

final class KixagoClientTests: XCTestCase {
    var mockSession: URLSessionMock!
    var client: KixagoClient!
    
    override func setUp() async throws {
        mockSession = URLSessionMock()
        client = KixagoClient(
            apiKey: "test-key",
            session: mockSession
        )
    }
    
    func testGetRiskProfileSuccess() async throws {
        // Arrange
        let mockResponse = """
        {
            "wallet_address": "0xTest123",
            "total_collateral_usd": 100000.0,
            "total_borrowed_usd": 30000.0,
            "global_health_factor": 3.2,
            "global_ltv": 30.0,
            "positions_at_risk_count": 0,
            "last_updated": "2025-01-15T12:00:00Z",
            "aggregation_duration": "1.234s",
            "lending_positions": [],
            "defi_score": {
                "defi_score": 750,
                "risk_level": "Very Low Risk",
                "risk_category": "VERY_LOW_RISK",
                "color": "green",
                "score_breakdown": {
                    "health_factor_score": { "component_score": 100, "weight": 0.4, "weighted_contribution": 40, "reasoning": "" },
                    "leverage_score": { "component_score": 100, "weight": 0.3, "weighted_contribution": 30, "reasoning": "" },
                    "diversification_score": { "component_score": 20, "weight": 0.15, "weighted_contribution": 3, "reasoning": "" },
                    "volatility_score": { "component_score": 100, "weight": 0.1, "weighted_contribution": 10, "reasoning": "" },
                    "protocol_risk_score": { "component_score": 95, "weight": 0.05, "weighted_contribution": 4.75, "reasoning": "" },
                    "total_internal_score": 87.75
                },
                "risk_factors": [],
                "recommendations": {
                    "immediate": [],
                    "short_term": [],
                    "long_term": []
                },
                "liquidation_simulation": {
                    "current_health_factor": 3.2,
                    "liquidation_threshold": 1.0,
                    "buffer_percentage": 220.0,
                    "scenarios": []
                },
                "calculated_at": "2025-01-15T12:00:00Z"
            }
        }
        """
        
        mockSession.mockData = mockResponse.data(using: .utf8)
        mockSession.mockResponse = HTTPURLResponse(
            url: URL(string: "https://api.kixago.com")!,
            statusCode: 200,
            httpVersion: nil,
            headerFields: nil
        )
        
        // Act
        let profile = try await client.getRiskProfile(walletAddress: "0xTest123")
        
        // Assert
        XCTAssertEqual(profile.walletAddress, "0xTest123")
        XCTAssertEqual(profile.defiScore?.defiScore, 750)
        XCTAssertEqual(profile.globalHealthFactor, 3.2, accuracy: 0.01)
    }
    
    func testGetRiskProfileUnauthorized() async {
        // Arrange
        mockSession.mockResponse = HTTPURLResponse(
            url: URL(string: "https://api.kixago.com")!,
            statusCode: 401,
            httpVersion: nil,
            headerFields: nil
        )
        mockSession.mockData = """
        {"error": "Invalid API key"}
        """.data(using: .utf8)
        
        // Act & Assert
        do {
            _ = try await client.getRiskProfile(walletAddress: "0xTest123")
            XCTFail("Expected unauthorized error")
        } catch KixagoError.unauthorized {
            // Expected
        } catch {
            XCTFail("Unexpected error: \(error)")
        }
    }
    
    func testRiskProfileHelperMethods() {
        // Arrange
        let profile = RiskProfileResponse(
            walletAddress: "0xTest",
            totalCollateralUsd: 100000,
            totalBorrowedUsd: 30000,
            globalHealthFactor: 3.2,
            globalLtv: 30.0,
            positionsAtRiskCount: 1,
            lastUpdated: Date(),
            aggregationDuration: "1s",
            lendingPositions: [
                LendingPosition(
                    protocol: "Aave",
                    protocolVersion: "V3",
                    chain: "Ethereum",
                    userAddress: "0xTest",
                    collateralUsd: 100000,
                    borrowedUsd: 30000,
                    healthFactor: 3.2,
                    ltvCurrent: 30.0,
                    isAtRisk: false,
                    collateralDetails: nil,
                    borrowedDetails: nil,
                    lastUpdated: Date()
                )
            ],
            defiScore: nil,
            aggregationErrors: nil
        )
        
        // Act & Assert
        XCTAssertTrue(profile.hasPositionsAtRisk)
        XCTAssertEqual(profile.positions(forChain: "Ethereum").count, 1)
        XCTAssertEqual(profile.collateral(forProtocol: "Aave"), 100000, accuracy: 0.01)
    }
}

// Mock URLSession for testing
class URLSessionMock: URLSession {
    var mockData: Data?
    var mockResponse: URLResponse?
    var mockError: Error?
    
    override func data(for request: URLRequest) async throws -> (Data, URLResponse) {
        if let error = mockError {
            throw error
        }
        
        return (mockData ?? Data(), mockResponse ?? URLResponse())
    }
}

Best Practices​

✅ DO​

  • Use async/await for concurrency - Modern Swift concurrency
  • Use Actor for thread-safe clients - Eliminate data races
  • Implement proper error types - Custom LocalizedError enum
  • Use Codable for JSON - Type-safe serialization
  • Handle optional values - Always unwrap safely
  • Use os.log or Logger - Structured logging
  • Cache responses - Use NSCache or custom actor-based cache
  • Use environment variables - Never hardcode API keys
  • Write unit tests - Mock URLSession for testing

❌ DON'T​

  • Don't use force unwrap (!) - Use optional binding or guard
  • Don't block main thread - Use Task or async
  • Don't ignore errors - Always handle with do-catch or Result
  • Don't use Double for precise values - Consider Decimal for money
  • Don't expose API keys - Use Xcode schemes or environment
  • Don't create new URLSession per request - Reuse session
  • Don't skip error context - Provide meaningful error messages

Performance Tips​

URLSession Configuration​

let config = URLSessionConfiguration.default
config.timeoutIntervalForRequest = 30
config.timeoutIntervalForResource = 60
config.requestCachePolicy = .useProtocolCachePolicy
config.httpMaximumConnectionsPerHost = 4

let session = URLSession(configuration: config)

Efficient JSON Decoding​

// Decode only what you need
struct MinimalProfile: Codable {
    let walletAddress: String
    let defiScore: Int?
    
    enum CodingKeys: String, CodingKey {
        case walletAddress = "wallet_address"
        case defiScore = "defi_score"
    }
    
    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        walletAddress = try container.decode(String.self, forKey: .walletAddress)
        
        // Nested score extraction
        if let scoreContainer = try? container.nestedContainer(
            keyedBy: ScoreCodingKeys.self,
            forKey: .defiScore
        ) {
            defiScore = try scoreContainer.decode(Int.self, forKey: .score)
        } else {
            defiScore = nil
        }
    }
    
    private enum ScoreCodingKeys: String, CodingKey {
        case score = "defi_score"
    }
}

Next Steps​

🤖 Kotlin Examples

🔷 Go Examples

✨ Best Practices

Need Help?​

  • Code not working? Email [email protected] with code snippet
  • Want a Swift SDK? Coming Q2 2025 - watch our GitHub
  • Found a bug? Report it
  • iOS/macOS specific issues? Check our

Why Swift for DeFi?​

Swift is excellent for building crypto apps because:

  • 🍎 Native iOS/macOS development - 150M+ potential users
  • ⚡ Performance - Compiled, type-safe, memory-efficient
  • 🔒 Modern concurrency - async/await, actors, structured concurrency
  • 🛡️ Type safety - Optionals prevent null crashes
  • 📱 SwiftUI - Build beautiful UIs fast
  • 🌐 Cross-platform - iOS, macOS, watchOS, visionOS

Popular crypto wallets using Swift:

  • Rainbow Wallet
  • Coinbase Wallet (iOS)
  • Trust Wallet (iOS)
  • MetaMask Mobile (parts)

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