getSwiftCode.ts•54.8 kB
import { Tool, ToolResult } from '../types/tool.js';
export const getSwiftCodeTool: Tool = {
name: 'ldk_get_swift_code',
description: 'Get Swift code examples for specific LDK operations',
inputSchema: {
type: 'object',
properties: {
operation: {
type: 'string',
enum: [
'channel_manager_setup',
'peer_connection',
'event_handling',
'persistence',
'network_sync',
'fee_estimation',
'routing',
'background_tasks'
],
description: 'Type of operation to get Swift code for'
}
},
required: ['operation']
},
execute: async (args: any): Promise<ToolResult> => {
const codeExamples: Record<string, string> = {
channel_manager_setup: `
// Complete ChannelManager setup in Swift using LDK
import LightningDevKit
class LDKManager {
private var channelManager: Bindings.ChannelManager!
private var channelManagerConstructor: Bindings.ChannelManagerConstructor!
private var keysManager: Bindings.KeysManager!
private var chainMonitor: Bindings.ChainMonitor!
private var networkGraph: Bindings.NetworkGraph!
private var scorer: Bindings.MultiThreadedLockableScore!
private var router: Bindings.DefaultRouter!
private var peerManager: Bindings.PeerManager!
private var logger: Bindings.Logger!
func initialize(network: Bindings.Network, seed: [UInt8]) async throws {
// 1. Initialize Keys Manager
let timestampSeconds = UInt64(Date().timeIntervalSince1970)
let timestampNanos = UInt32(timestampSeconds * 1000 * 1000)
keysManager = Bindings.KeysManager(
seed: seed,
startingTimeSecs: timestampSeconds,
startingTimeNanos: timestampNanos
)
// 2. Initialize Fee Estimator
let feeEstimator = MyFeeEstimator()
// 3. Initialize Logger
let logger = MyLogger()
// 4. Initialize Broadcaster
let broadcaster = MyBroadcaster()
// 5. Initialize Persister
let persister = MyPersister()
// 6. Initialize Filter (for light clients)
let filter = MyFilter()
// 7. Initialize Chain Monitor
chainMonitor = Bindings.ChainMonitor(
chainSource: filter,
broadcaster: broadcaster,
logger: logger,
feeEstimator: feeEstimator,
persister: persister
)
// 8. Initialize Network Graph
let serializedGraph = loadNetworkGraph() // Load from disk if exists
if let graphBytes = serializedGraph {
let readResult = Bindings.NetworkGraph.read(ser: graphBytes, arg: logger)
if readResult.isOk() {
networkGraph = readResult.getValue()!
} else {
networkGraph = Bindings.NetworkGraph(network: network, logger: logger)
}
} else {
networkGraph = Bindings.NetworkGraph(network: network, logger: logger)
}
// 9. Initialize Router
let decayParams = Bindings.ProbabilisticScoringDecayParameters.initWithDefault()
let probabilisticScorer = Bindings.ProbabilisticScorer(
decayParams: decayParams,
networkGraph: networkGraph,
logger: logger
)
scorer = Bindings.MultiThreadedLockableScore(score: probabilisticScorer.asScore())
// 10. Initialize Channel Manager
let channelMonitors = loadChannelMonitors() // Load from disk
let serializedManager = loadChannelManager() // Load from disk if exists
let constructorParams = Bindings.ChannelManagerConstructionParameters(
config: Bindings.UserConfig.initWithDefault(),
entropySource: keysManager.asEntropySource(),
nodeSigner: keysManager.asNodeSigner(),
signerProvider: keysManager.asSignerProvider(),
feeEstimator: feeEstimator,
chainMonitor: chainMonitor,
txBroadcaster: broadcaster,
logger: logger,
router: Bindings.DefaultRouter(
networkGraph: networkGraph,
logger: logger,
randomSeedBytes: keysManager.asEntropySource().getSecureRandomBytes(),
scorer: scorer,
scoreParams: Bindings.ProbabilisticScoringFeeParameters.initWithDefault()
)
)
if let managerBytes = serializedManager, !managerBytes.isEmpty {
// Restart - load from serialized
do {
channelManagerConstructor = try Bindings.ChannelManagerConstructor(
channelManagerSerialized: managerBytes,
channelMonitorsSerialized: channelMonitors,
networkGraph: Bindings.NetworkGraphArgument.instance(networkGraph),
filter: filter,
params: constructorParams
)
} catch {
// Fresh start if loading fails
channelManagerConstructor = createFreshChannelManager(params: constructorParams)
}
} else {
// Fresh start
channelManagerConstructor = createFreshChannelManager(params: constructorParams)
}
channelManager = channelManagerConstructor.channelManager
// 11. Sync to chain tip
await syncToChainTip()
// 12. Start background processing
channelManagerConstructor.chainSyncCompleted(persister: MyEventHandler())
}
private func createFreshChannelManager(params: Bindings.ChannelManagerConstructionParameters) -> Bindings.ChannelManagerConstructor {
let (blockHash, blockHeight) = getChainTip()
return Bindings.ChannelManagerConstructor(
network: network,
currentBlockchainTipHash: blockHash,
currentBlockchainTipHeight: blockHeight,
netGraph: networkGraph,
params: params
)
}
}`.trim(),
peer_connection: `
// Peer connection management in Swift
import LightningDevKit
class PeerConnectionManager {
private let peerManager: PeerManager
private var connections: [String: TcpPeerHandler] = [:]
init(channelManagerConstructor: ChannelManagerConstructor) {
self.peerManager = channelManagerConstructor.peerManager
}
func connectToPeer(pubkey: String, address: String, port: UInt16) async throws {
guard let pubkeyData = Data(hexString: pubkey),
pubkeyData.count == 33 else {
throw PeerError.invalidPubkey
}
// Check if already connected
let connectedPeers = peerManager.getPeerNodeIds()
if connectedPeers.contains(where: { $0.0 == pubkeyData.bytes }) {
print("Already connected to peer")
return
}
// Create TCP connection handler
let tcpHandler = TCPPeerHandler(
peerManager: peerManager,
socketAddress: address,
port: port
)
// Initiate connection
let connected = await tcpHandler.connect()
guard connected else {
throw PeerError.connectionFailed
}
// Store connection
connections[pubkey] = tcpHandler
// Start message processing
tcpHandler.startMessageHandling()
}
func disconnectPeer(pubkey: String) {
guard let pubkeyData = Data(hexString: pubkey),
pubkeyData.count == 33 else {
return
}
peerManager.disconnectByNodeId(nodeId: pubkeyData.bytes)
connections.removeValue(forKey: pubkey)
}
func listConnectedPeers() -> [(pubkey: String, address: String)] {
return peerManager.getPeerNodeIds().compactMap { peer in
let pubkey = Data(peer.0).hexString
if let connection = connections[pubkey] {
return (pubkey: pubkey, address: connection.remoteAddress)
}
return nil
}
}
}
// TCP Connection Handler
class TCPPeerHandler {
private let peerManager: PeerManager
private let socketAddress: String
private let port: UInt16
private var connection: NWConnection?
var remoteAddress: String {
return "\\(socketAddress):\\(port)"
}
init(peerManager: PeerManager, socketAddress: String, port: UInt16) {
self.peerManager = peerManager
self.socketAddress = socketAddress
self.port = port
}
func connect() async -> Bool {
let host = NWEndpoint.Host(socketAddress)
let port = NWEndpoint.Port(rawValue: self.port)!
connection = NWConnection(host: host, port: port, using: .tcp)
let connected = await withCheckedContinuation { continuation in
connection?.stateUpdateHandler = { state in
switch state {
case .ready:
continuation.resume(returning: true)
case .failed(_), .cancelled:
continuation.resume(returning: false)
default:
break
}
}
connection?.start(queue: .global())
}
return connected
}
func startMessageHandling() {
receiveMessage()
}
private func receiveMessage() {
connection?.receive(minimumIncompleteLength: 1, maximumLength: 65536) { data, _, isComplete, error in
if let data = data, !data.isEmpty {
// Process received data through peer manager
let result = self.peerManager.readEvent(
peerDescriptor: self.getDescriptor(),
data: [UInt8](data)
)
if result.isOk() {
// Continue receiving
self.receiveMessage()
}
}
if isComplete || error != nil {
// Connection closed
self.handleDisconnection()
}
}
}
private func handleDisconnection() {
// Clean up
connection?.cancel()
connection = nil
}
private func getDescriptor() -> SocketDescriptor {
// Implementation of socket descriptor for this connection
return MySocketDescriptor(connection: connection!)
}
}`.trim(),
event_handling: `
// Comprehensive event handling in Swift
import LightningDevKit
import BitcoinDevKit
class LDKEventHandler: Bindings.EventHandler {
private let channelManager: Bindings.ChannelManager
private let wallet: BitcoinDevKit.Wallet
private let keysManager: Bindings.KeysManager
init(channelManager: Bindings.ChannelManager, wallet: BitcoinDevKit.Wallet, keysManager: Bindings.KeysManager) {
self.channelManager = channelManager
self.wallet = wallet
self.keysManager = keysManager
super.init()
}
override func handleEvent(event: Bindings.Event) {
switch event.getValueType() {
case .FundingGenerationReady:
handleFundingGeneration(event.getValueAsFundingGenerationReady()!)
case .PaymentClaimable:
handlePaymentClaimable(event.getValueAsPaymentClaimable()!)
case .PaymentSent:
handlePaymentSent(event.getValueAsPaymentSent()!)
case .PaymentFailed:
handlePaymentFailed(event.getValueAsPaymentFailed()!)
case .PaymentPathSuccessful:
handlePaymentPathSuccessful(event.getValueAsPaymentPathSuccessful()!)
case .PaymentPathFailed:
handlePaymentPathFailed(event.getValueAsPaymentPathFailed()!)
case .PaymentForwarded:
handlePaymentForwarded(event.getValueAsPaymentForwarded()!)
case .ChannelReady:
handleChannelReady(event.getValueAsChannelReady()!)
case .ChannelClosed:
handleChannelClosed(event.getValueAsChannelClosed()!)
case .SpendableOutputs:
handleSpendableOutputs(event.getValueAsSpendableOutputs()!)
case .HTLCIntercepted:
handleHTLCIntercepted(event.getValueAsHTLCIntercepted()!)
default:
print("Unhandled event type: \\(event.getValueType())")
}
}
private func handleFundingGeneration(_ event: Bindings.Event.FundingGenerationReady) {
Task {
do {
let outputScript = Script(rawOutputScript: event.getOutputScript())
let amount = event.getChannelValueSatoshis()
// Build funding transaction
let txBuilder = try TxBuilder()
.addRecipient(script: outputScript, amount: amount)
.feeRate(satPerVbyte: 5.0)
.enableRbf()
let psbt = try txBuilder.finish(wallet: wallet)
let signed = try wallet.sign(psbt: psbt, signOptions: nil)
let fundingTx = signed.extractTx()
// Provide to channel manager
channelManager.fundingTransactionGenerated(
temporaryChannelId: event.getTemporaryChannelId(),
counterpartyNodeId: event.getCounterpartyNodeId(),
fundingTransaction: fundingTx.serialize()
)
// Broadcast transaction
try await broadcastTransaction(fundingTx)
// Notify UI
NotificationCenter.default.post(
name: .channelPendingFunding,
object: nil,
userInfo: ["channelId": event.getTemporaryChannelId().toHex()]
)
} catch {
print("Funding generation failed: \\(error)")
}
}
}
private func handlePaymentClaimable(_ event: Bindings.Event.PaymentClaimable) {
let paymentHash = event.getPaymentHash()
let amountMsat = event.getClaimableAmountMsat()
let purpose = event.getPurpose()
// Claim the payment
channelManager.claimFunds(paymentPreimage: event.getPaymentPreimage())
// Update UI
DispatchQueue.main.async {
NotificationCenter.default.post(
name: .paymentReceived,
object: nil,
userInfo: [
"paymentHash": paymentHash.toHex(),
"amountMsat": amountMsat,
"description": purpose.description ?? ""
]
)
}
// Show notification
LightningNotificationService.notifyPaymentReceived(
amountMsat: amountMsat,
description: purpose.description
)
}
private func handlePaymentSent(_ event: Bindings.Event.PaymentSent) {
let paymentHash = event.getPaymentHash()
let paymentPreimage = event.getPaymentPreimage()
let feePaidMsat = event.getFeePaidMsat()?.getValue() ?? 0
// Update payment record
PaymentStore.shared.markPaymentSucceeded(
paymentHash: paymentHash.toHex(),
preimage: paymentPreimage.toHex(),
feeMsat: feePaidMsat
)
// Update UI
DispatchQueue.main.async {
NotificationCenter.default.post(
name: .paymentSent,
object: nil,
userInfo: [
"paymentHash": paymentHash.toHex(),
"feeMsat": feePaidMsat
]
)
}
}
private func handleSpendableOutputs(_ event: Bindings.Event.SpendableOutputs) {
let outputs = event.getOutputs()
Task {
do {
// Get sweep address
let address = try wallet.getAddress(addressIndex: .new)
let script = try Address(
address: address.address.asString(),
network: .testnet
).scriptPubkey().toBytes()
// Build sweep transaction
let result = keysManager.spendSpendableOutputs(
descriptors: outputs,
outputs: [],
changeDestinationScript: script,
feerateSatPer1000Weight: 1000,
locktime: nil
)
if result.isOk(), let tx = result.getValue() {
// Broadcast
try await broadcastTransaction(Data(tx))
print("Swept \\(outputs.count) spendable outputs")
}
} catch {
print("Failed to sweep outputs: \\(error)")
}
}
}
}
// Notification extensions
extension Notification.Name {
static let channelPendingFunding = Notification.Name("ldkChannelPendingFunding")
static let paymentReceived = Notification.Name("ldkPaymentReceived")
static let paymentSent = Notification.Name("ldkPaymentSent")
static let channelReady = Notification.Name("ldkChannelReady")
static let channelClosed = Notification.Name("ldkChannelClosed")
}`.trim(),
persistence: `
// Channel and state persistence in Swift
import LightningDevKit
import Foundation
class LDKPersistence: Persist, Persister {
private let documentsDirectory: URL
private let channelMonitorDirectory: URL
private let channelManagerPath: URL
private let networkGraphPath: URL
private let scorerPath: URL
init() throws {
// Setup directories
documentsDirectory = FileManager.default.urls(
for: .documentDirectory,
in: .userDomainMask
).first!
let ldkDirectory = documentsDirectory.appendingPathComponent("ldk")
channelMonitorDirectory = ldkDirectory.appendingPathComponent("channel_monitors")
channelManagerPath = ldkDirectory.appendingPathComponent("channel_manager.bin")
networkGraphPath = ldkDirectory.appendingPathComponent("network_graph.bin")
scorerPath = ldkDirectory.appendingPathComponent("scorer.bin")
// Create directories
try FileManager.default.createDirectory(
at: channelMonitorDirectory,
withIntermediateDirectories: true
)
}
// MARK: - Persist Protocol (for ChannelMonitor)
override func persistNewChannel(
channelId: OutPoint,
data: ChannelMonitor,
updateId: MonitorUpdateId
) -> ChannelMonitorUpdateStatus {
let channelIdHex = channelId.toChannelId().toHex()
let monitorPath = channelMonitorDirectory
.appendingPathComponent("\\(channelIdHex).bin")
do {
let serialized = data.write()
try Data(serialized).write(to: monitorPath)
// Backup to iCloud
backupToICloud(data: Data(serialized), filename: "\\(channelIdHex).bin")
return .completed
} catch {
print("Failed to persist new channel: \\(error)")
return .permanentFailure
}
}
override func updatePersistedChannel(
channelId: OutPoint,
update: ChannelMonitorUpdate?,
data: ChannelMonitor,
updateId: MonitorUpdateId
) -> ChannelMonitorUpdateStatus {
// For simplicity, we'll just persist the full monitor
// In production, you might want to store updates separately
return persistNewChannel(
channelId: channelId,
data: data,
updateId: updateId
)
}
// MARK: - Persister Protocol (for ChannelManager)
override func persistManager(channelManager: ChannelManager) -> Result_NoneIOErrorZ {
do {
let serialized = channelManager.write()
try Data(serialized).write(to: channelManagerPath)
return Result_NoneIOErrorZ.initWithOk()
} catch {
return Result_NoneIOErrorZ.initWithErr(e: .init())
}
}
override func persistGraph(networkGraph: NetworkGraph) -> Result_NoneIOErrorZ {
do {
let serialized = networkGraph.write()
try Data(serialized).write(to: networkGraphPath)
return Result_NoneIOErrorZ.initWithOk()
} catch {
return Result_NoneIOErrorZ.initWithErr(e: .init())
}
}
override func persistScorer(scorer: WriteableScore) -> Result_NoneIOErrorZ {
do {
let serialized = scorer.write()
try Data(serialized).write(to: scorerPath)
return Result_NoneIOErrorZ.initWithOk()
} catch {
return Result_NoneIOErrorZ.initWithErr(e: .init())
}
}
// MARK: - Loading Methods
func loadChannelMonitors() -> [[UInt8]] {
var monitors: [[UInt8]] = []
do {
let files = try FileManager.default.contentsOfDirectory(
at: channelMonitorDirectory,
includingPropertiesForKeys: nil
)
for file in files where file.pathExtension == "bin" {
let data = try Data(contentsOf: file)
monitors.append([UInt8](data))
}
} catch {
print("Failed to load channel monitors: \\(error)")
}
return monitors
}
func loadChannelManager() -> [UInt8]? {
do {
let data = try Data(contentsOf: channelManagerPath)
return [UInt8](data)
} catch {
return nil
}
}
func loadNetworkGraph() -> [UInt8]? {
do {
let data = try Data(contentsOf: networkGraphPath)
return [UInt8](data)
} catch {
return nil
}
}
func loadScorer() -> [UInt8]? {
do {
let data = try Data(contentsOf: scorerPath)
return [UInt8](data)
} catch {
return nil
}
}
// MARK: - iCloud Backup
private func backupToICloud(data: Data, filename: String) {
guard let containerURL = FileManager.default.url(
forUbiquityContainerIdentifier: nil
) else { return }
let backupDirectory = containerURL
.appendingPathComponent("Documents")
.appendingPathComponent("ldk_backup")
do {
try FileManager.default.createDirectory(
at: backupDirectory,
withIntermediateDirectories: true
)
let backupPath = backupDirectory.appendingPathComponent(filename)
try data.write(to: backupPath)
} catch {
print("iCloud backup failed: \\(error)")
}
}
}
// Extension for automatic persistence
extension ChannelManager {
func setupAutoPersistence(persister: LDKPersistence) {
// Persist after every update
Timer.scheduledTimer(withTimeInterval: 30, repeats: true) { _ in
_ = persister.persistManager(channelManager: self)
}
}
}`.trim(),
network_sync: `
// Network synchronization in Swift
import LightningDevKit
class NetworkSynchronizer {
private let channelManager: ChannelManager
private let chainMonitor: ChainMonitor
private let rapidGossipSync: RapidGossipSync?
private var syncTimer: Timer?
init(channelManager: ChannelManager, chainMonitor: ChainMonitor, networkGraph: NetworkGraph, logger: Logger) {
self.channelManager = channelManager
self.chainMonitor = chainMonitor
self.rapidGossipSync = RapidGossipSync(networkGraph: networkGraph, logger: logger)
}
// MARK: - Chain Sync (Electrum/Esplora)
func syncWithElectrum(client: ElectrumClient) async throws {
// Get relevant transactions to monitor
let relevantTxIds = getRelevantTransactions()
// Check for reorgs
let unconfirmedTxs = try await client.checkReorgs(txIds: relevantTxIds)
for txid in unconfirmedTxs {
channelManager.asConfirm().transactionUnconfirmed(txid: txid)
chainMonitor.asConfirm().transactionUnconfirmed(txid: txid)
}
// Get confirmed transactions
let confirmedTxs = try await client.getConfirmedTransactions(
addresses: getWatchedAddresses()
)
for tx in confirmedTxs {
let header = try await client.getBlockHeader(height: tx.height)
let txData = [(tx.position, tx.rawTx)]
channelManager.asConfirm().transactionsConfirmed(
header: header,
txdata: txData,
height: tx.height
)
chainMonitor.asConfirm().transactionsConfirmed(
header: header,
txdata: txData,
height: tx.height
)
}
// Update to chain tip
let (tipHash, tipHeight) = try await client.getChainTip()
channelManager.asConfirm().bestBlockUpdated(
header: tipHash,
height: tipHeight
)
chainMonitor.asConfirm().bestBlockUpdated(
header: tipHash,
height: tipHeight
)
}
// MARK: - Rapid Gossip Sync
func syncGossip() async {
guard let rgs = rapidGossipSync else { return }
let lastSync = networkGraph.getLastRapidGossipSyncTimestamp() ?? 0
let url = URL(string: "https://rapidsync.lightningdevkit.org/snapshot/\\(lastSync)")!
do {
let (data, _) = try await URLSession.shared.data(from: url)
let timestamp = UInt64(Date().timeIntervalSince1970)
let result = rgs.updateNetworkGraphNoStd(
updateData: [UInt8](data),
currentTimeUnix: timestamp
)
if result.isOk() {
print("Gossip sync successful")
}
} catch {
print("Gossip sync failed: \\(error)")
}
}
// MARK: - Background Sync
func startBackgroundSync(interval: TimeInterval = 30) {
syncTimer = Timer.scheduledTimer(
withTimeInterval: interval,
repeats: true
) { _ in
Task {
await self.performBackgroundSync()
}
}
}
func stopBackgroundSync() {
syncTimer?.invalidate()
syncTimer = nil
}
private func performBackgroundSync() async {
// Sync chain data
do {
let client = ElectrumClient(server: "electrum.blockstream.info")
try await syncWithElectrum(client: client)
} catch {
print("Chain sync failed: \\(error)")
}
// Sync gossip data
await syncGossip()
// Process pending events
channelManager.processPendingHtlcForwards()
// Persist state
LDKManager.shared.persistState()
}
// MARK: - Helpers
private func getRelevantTransactions() -> [[UInt8]] {
var txIds: [[UInt8]] = []
// Get from channel manager
let channelTxs = channelManager.asConfirm().getRelevantTxids()
txIds.append(contentsOf: channelTxs.map { $0.0 })
// Get from chain monitor
let monitorTxs = chainMonitor.asConfirm().getRelevantTxids()
txIds.append(contentsOf: monitorTxs.map { $0.0 })
return txIds
}
private func getWatchedAddresses() -> [String] {
// Implementation depends on your Filter
return LDKManager.shared.filter.getWatchedAddresses()
}
}
// Electrum Client Helper
class ElectrumClient {
private let server: String
struct ConfirmedTransaction {
let txid: [UInt8]
let rawTx: [UInt8]
let height: UInt32
let position: UInt
}
init(server: String) {
self.server = server
}
func checkReorgs(txIds: [[UInt8]]) async throws -> [[UInt8]] {
// Check if transactions are still confirmed
var unconfirmed: [[UInt8]] = []
for txid in txIds {
let confirmed = try await isTransactionConfirmed(txid: txid)
if !confirmed {
unconfirmed.append(txid)
}
}
return unconfirmed
}
func getConfirmedTransactions(addresses: [String]) async throws -> [ConfirmedTransaction] {
// Fetch transaction history for addresses
var transactions: [ConfirmedTransaction] = []
for address in addresses {
let history = try await getAddressHistory(address: address)
transactions.append(contentsOf: history)
}
return transactions
}
func getChainTip() async throws -> ([UInt8], UInt32) {
// Get current best block
// Implementation depends on Electrum protocol
return ([], 0)
}
// Additional helper methods...
}`.trim(),
fee_estimation: `
// Fee estimation implementation in Swift
import LightningDevKit
class LDKFeeEstimator: FeeEstimator {
private var feeRates: [ConfirmationTarget: UInt32] = [:]
private let minFeeRate: UInt32 = 253 // 1 sat/vbyte
private let defaultFeeRates: [ConfirmationTarget: UInt32] = [
.onChainSweep: 5000, // 20 sat/vbyte
.maxAllowedNonAnchorChannelRemoteFee: 25000, // 100 sat/vbyte
.minAllowedAnchorChannelRemoteFee: 253, // 1 sat/vbyte
.minAllowedNonAnchorChannelRemoteFee: 253, // 1 sat/vbyte
.anchorChannelFee: 1000, // 4 sat/vbyte
.nonAnchorChannelFee: 2000, // 8 sat/vbyte
.channelCloseMinimum: 500, // 2 sat/vbyte
.outputSpendingFee: 3000 // 12 sat/vbyte
]
override init() {
super.init()
self.feeRates = defaultFeeRates
startFeeUpdateTimer()
}
override func getEstSatPer1000Weight(confirmationTarget: ConfirmationTarget) -> UInt32 {
return feeRates[confirmationTarget] ?? defaultFeeRates[confirmationTarget] ?? minFeeRate
}
// Update fees from external source
func updateFeeEstimates() async {
do {
// Fetch from mempool.space API
let url = URL(string: "https://mempool.space/api/v1/fees/recommended")!
let (data, _) = try await URLSession.shared.data(from: url)
struct FeeRecommendation: Codable {
let fastestFee: Int
let halfHourFee: Int
let hourFee: Int
let economyFee: Int
let minimumFee: Int
}
let fees = try JSONDecoder().decode(FeeRecommendation.self, from: data)
// Convert sat/vbyte to sat/1000 weight
// 1 vbyte = 4 weight units, so sat/vbyte * 250 = sat/1000 weight
feeRates[.onChainSweep] = UInt32(fees.fastestFee * 250)
feeRates[.maxAllowedNonAnchorChannelRemoteFee] = UInt32(fees.fastestFee * 250 * 5) // 5x for max
feeRates[.anchorChannelFee] = UInt32(fees.halfHourFee * 250)
feeRates[.nonAnchorChannelFee] = UInt32(fees.halfHourFee * 250)
feeRates[.channelCloseMinimum] = UInt32(fees.economyFee * 250)
feeRates[.outputSpendingFee] = UInt32(fees.hourFee * 250)
// Ensure minimum rates
for (target, _) in feeRates {
if let rate = feeRates[target] {
feeRates[target] = max(rate, minFeeRate)
}
}
print("Updated fee estimates: \\(fees)")
} catch {
print("Failed to update fee estimates: \\(error)")
}
}
private func startFeeUpdateTimer() {
Timer.scheduledTimer(withTimeInterval: 300, repeats: true) { _ in
Task {
await self.updateFeeEstimates()
}
}
// Initial update
Task {
await updateFeeEstimates()
}
}
}
// SwiftUI Fee Estimator View
struct FeeEstimatorView: View {
@StateObject private var feeEstimator = FeeEstimatorViewModel()
var body: some View {
List {
Section("Current Fee Rates") {
FeeRateRow(
label: "High Priority",
description: "~10 minutes",
satPerVbyte: feeEstimator.highPriority
)
FeeRateRow(
label: "Medium Priority",
description: "~30 minutes",
satPerVbyte: feeEstimator.mediumPriority
)
FeeRateRow(
label: "Low Priority",
description: "~1 hour",
satPerVbyte: feeEstimator.lowPriority
)
FeeRateRow(
label: "Economy",
description: "~24 hours",
satPerVbyte: feeEstimator.economy
)
}
Section("Channel Operations") {
Text("Channel Open: ~\\(feeEstimator.channelOpenCost) sats")
Text("Channel Close: ~\\(feeEstimator.channelCloseCost) sats")
Text("Force Close: ~\\(feeEstimator.forceCloseCost) sats")
}
Section {
HStack {
Text("Last Updated")
Spacer()
Text(feeEstimator.lastUpdated, style: .relative)
.foregroundColor(.secondary)
}
}
}
.navigationTitle("Fee Estimates")
.refreshable {
await feeEstimator.refresh()
}
}
}
struct FeeRateRow: View {
let label: String
let description: String
let satPerVbyte: Int
var body: some View {
HStack {
VStack(alignment: .leading, spacing: 4) {
Text(label)
.font(.headline)
Text(description)
.font(.caption)
.foregroundColor(.secondary)
}
Spacer()
Text("\\(satPerVbyte) sat/vB")
.font(.system(.body, design: .monospaced))
.foregroundColor(.orange)
}
.padding(.vertical, 4)
}
}
class FeeEstimatorViewModel: ObservableObject {
@Published var highPriority: Int = 0
@Published var mediumPriority: Int = 0
@Published var lowPriority: Int = 0
@Published var economy: Int = 0
@Published var lastUpdated = Date()
private let feeEstimator: LDKFeeEstimator
init() {
self.feeEstimator = LDKManager.shared.feeEstimator
updateRates()
}
var channelOpenCost: Int {
// Approximate channel open transaction size: 200 vbytes
return mediumPriority * 200
}
var channelCloseCost: Int {
// Approximate cooperative close: 150 vbytes
return lowPriority * 150
}
var forceCloseCost: Int {
// Force close with justice transaction: 300 vbytes
return highPriority * 300
}
func refresh() async {
await feeEstimator.updateFeeEstimates()
updateRates()
}
private func updateRates() {
// Convert from sat/1000weight to sat/vbyte
highPriority = Int(feeEstimator.getEstSatPer1000Weight(confirmationTarget: .onChainSweep) / 250)
mediumPriority = Int(feeEstimator.getEstSatPer1000Weight(confirmationTarget: .anchorChannelFee) / 250)
lowPriority = Int(feeEstimator.getEstSatPer1000Weight(confirmationTarget: .nonAnchorChannelFee) / 250)
economy = Int(feeEstimator.getEstSatPer1000Weight(confirmationTarget: .channelCloseMinimum) / 250)
lastUpdated = Date()
}
}`.trim(),
routing: `
// Lightning routing implementation in Swift
import LightningDevKit
class LightningRouter {
private let router: Bindings.DefaultRouter
private let networkGraph: Bindings.NetworkGraph
private let scorer: Bindings.MultiThreadedLockableScore
private let logger: Bindings.Logger
init(networkGraph: Bindings.NetworkGraph, scorer: Bindings.MultiThreadedLockableScore, logger: Bindings.Logger, keysManager: Bindings.KeysManager) {
self.networkGraph = networkGraph
self.scorer = scorer
self.logger = logger
self.router = Bindings.DefaultRouter(
networkGraph: networkGraph,
logger: logger,
randomSeedBytes: keysManager.asEntropySource().getSecureRandomBytes(),
scorer: scorer,
scoreParams: Bindings.ProbabilisticScoringFeeParameters.initWithDefault()
)
}
func findRoute(
paymentParams: PaymentParameters,
amountMsat: UInt64,
payerPubkey: [UInt8]
) -> Result_RouteLightningErrorZ {
let channelManager = LDKManager.shared.channelManager
let channels = channelManager.listUsableChannels()
let routeParams = RouteParameters(
paymentParamsArg: paymentParams,
finalValueMsatArg: amountMsat,
maxTotalRoutingFeeMsatArg: amountMsat / 100 // 1% max fee
)
return router.findRoute(
payer: payerPubkey,
routeParams: routeParams,
firstHops: channels,
inflightHtlcs: InFlightHtlcs()
)
}
func findRouteForInvoice(invoice: Bolt11Invoice) -> RouteResult {
guard let paymentParams = paymentParametersFromInvoice(invoice: invoice) else {
return .failure(.invalidInvoice)
}
let amountMsat = invoice.amountMilliSatoshis()?.getValue() ?? 0
guard amountMsat > 0 else {
return .failure(.zeroAmount)
}
let ourNodeId = LDKManager.shared.channelManager.getOurNodeId()
let routeResult = findRoute(
paymentParams: paymentParams.recipientOnion,
amountMsat: amountMsat,
payerPubkey: ourNodeId
)
if let route = routeResult.getValue() {
return .success(RouteInfo(from: route))
} else if let error = routeResult.getError() {
return .failure(.routingError(error.getDescription()))
} else {
return .failure(.unknownError)
}
}
// Route analysis
func analyzeRoute(_ route: Route) -> RouteAnalysis {
let hops = route.getHops()
var totalFees: UInt64 = 0
var totalCltv: UInt32 = 0
var hopDetails: [HopDetail] = []
for (index, hop) in hops.enumerated() {
let fee = hop.getFeeMsat()
totalFees += fee
totalCltv += hop.getCltvExpiryDelta()
hopDetails.append(HopDetail(
nodeId: Data(hop.getPubkey()).hexString,
shortChannelId: hop.getShortChannelId(),
feeMsat: fee,
cltvDelta: hop.getCltvExpiryDelta()
))
}
return RouteAnalysis(
hops: hopDetails,
totalFeeMsat: totalFees,
totalCltvDelta: totalCltv,
successProbability: estimateSuccessProbability(route)
)
}
private func estimateSuccessProbability(_ route: Route) -> Double {
// Simple probability estimate based on number of hops
let hopCount = route.getHops().count
return max(0.5, 1.0 - (Double(hopCount) * 0.1))
}
}
// Route models
enum RouteResult {
case success(RouteInfo)
case failure(RouteError)
}
enum RouteError {
case invalidInvoice
case zeroAmount
case noRoute
case routingError(String)
case unknownError
}
struct RouteInfo {
let hops: [HopInfo]
let totalFeeMsat: UInt64
let totalAmountMsat: UInt64
init(from route: Route) {
self.hops = route.getHops().map { HopInfo(from: $0) }
self.totalFeeMsat = route.getTotalFees()
self.totalAmountMsat = route.getTotalAmount()
}
}
struct HopInfo {
let pubkey: String
let shortChannelId: UInt64
let feeMsat: UInt64
let cltvExpiryDelta: UInt32
init(from hop: RouteHop) {
self.pubkey = Data(hop.getPubkey()).hexString
self.shortChannelId = hop.getShortChannelId()
self.feeMsat = hop.getFeeMsat()
self.cltvExpiryDelta = hop.getCltvExpiryDelta()
}
}
struct RouteAnalysis {
let hops: [HopDetail]
let totalFeeMsat: UInt64
let totalCltvDelta: UInt32
let successProbability: Double
}
struct HopDetail {
let nodeId: String
let shortChannelId: UInt64
let feeMsat: UInt64
let cltvDelta: UInt32
}
// SwiftUI Route Visualization
struct RouteVisualizationView: View {
let route: RouteInfo
var body: some View {
ScrollView {
VStack(alignment: .leading, spacing: 16) {
// Route summary
VStack(alignment: .leading, spacing: 8) {
Text("Route Summary")
.font(.headline)
HStack {
Label("Total Fee", systemImage: "bitcoinsign.circle")
Spacer()
Text("\\(route.totalFeeMsat / 1000) sats")
.fontWeight(.medium)
}
HStack {
Label("Hops", systemImage: "arrow.right.circle")
Spacer()
Text("\\(route.hops.count)")
.fontWeight(.medium)
}
}
.padding()
.background(Color(UIColor.secondarySystemBackground))
.cornerRadius(12)
// Route path
Text("Route Path")
.font(.headline)
.padding(.top)
ForEach(Array(route.hops.enumerated()), id: \\.offset) { index, hop in
HopView(hop: hop, index: index, isLast: index == route.hops.count - 1)
}
}
.padding()
}
.navigationTitle("Payment Route")
}
}
struct HopView: View {
let hop: HopInfo
let index: Int
let isLast: Bool
var body: some View {
VStack(alignment: .leading, spacing: 0) {
HStack {
// Hop indicator
ZStack {
Circle()
.fill(Color.blue)
.frame(width: 30, height: 30)
Text("\\(index + 1)")
.font(.caption)
.fontWeight(.bold)
.foregroundColor(.white)
}
// Hop details
VStack(alignment: .leading, spacing: 4) {
Text(hop.pubkey.prefix(16) + "...")
.font(.system(.caption, design: .monospaced))
HStack {
Text("Channel: \\(hop.shortChannelId)")
.font(.caption2)
.foregroundColor(.secondary)
Spacer()
Text("Fee: \\(hop.feeMsat) msat")
.font(.caption2)
.foregroundColor(.orange)
}
}
.padding(.leading, 8)
}
if !isLast {
// Connection line
Rectangle()
.fill(Color.blue.opacity(0.3))
.frame(width: 2, height: 30)
.offset(x: 15)
}
}
}
}`.trim(),
background_tasks: `
// iOS Background task implementation for Lightning
import BackgroundTasks
import LightningDevKit
class LightningBackgroundTaskManager {
static let shared = LightningBackgroundTaskManager()
// Task identifiers
static let syncTaskId = "com.yourapp.lightning.sync"
static let monitorTaskId = "com.yourapp.lightning.monitor"
static let maintenanceTaskId = "com.yourapp.lightning.maintenance"
private var activeTasks: Set<BGTask> = []
func registerBackgroundTasks() {
// Register sync task
BGTaskScheduler.shared.register(
forTaskWithIdentifier: Self.syncTaskId,
using: nil
) { task in
self.handleSyncTask(task as! BGProcessingTask)
}
// Register monitor task
BGTaskScheduler.shared.register(
forTaskWithIdentifier: Self.monitorTaskId,
using: nil
) { task in
self.handleMonitorTask(task as! BGAppRefreshTask)
}
// Register maintenance task
BGTaskScheduler.shared.register(
forTaskWithIdentifier: Self.maintenanceTaskId,
using: nil
) { task in
self.handleMaintenanceTask(task as! BGProcessingTask)
}
}
func scheduleBackgroundTasks() {
scheduleSyncTask()
scheduleMonitorTask()
scheduleMaintenanceTask()
}
// MARK: - Sync Task (Heavy processing)
private func scheduleSyncTask() {
let request = BGProcessingTaskRequest(identifier: Self.syncTaskId)
request.requiresNetworkConnectivity = true
request.requiresExternalPower = false
request.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60) // 15 minutes
do {
try BGTaskScheduler.shared.submit(request)
} catch {
print("Failed to schedule sync task: \\(error)")
}
}
private func handleSyncTask(_ task: BGProcessingTask) {
activeTasks.insert(task)
// Schedule next sync
scheduleSyncTask()
// Set expiration handler
task.expirationHandler = {
self.cancelSync()
task.setTaskCompleted(success: false)
self.activeTasks.remove(task)
}
// Perform sync
Task {
let success = await performFullSync()
task.setTaskCompleted(success: success)
self.activeTasks.remove(task)
}
}
private func performFullSync() async -> Bool {
do {
// Initialize LDK if needed
if !LDKManager.shared.isInitialized {
try await LDKManager.shared.initialize()
}
// Sync to chain tip
try await LDKManager.shared.syncToChainTip()
// Process pending events
LDKManager.shared.processPendingEvents()
// Update network graph
await LDKManager.shared.syncNetworkGraph()
// Check for incoming payments
let receivedPayments = await checkIncomingPayments()
if !receivedPayments.isEmpty {
notifyPaymentsReceived(receivedPayments)
}
// Persist state
LDKManager.shared.persistState()
return true
} catch {
print("Background sync failed: \\(error)")
return false
}
}
// MARK: - Monitor Task (Lightweight)
private func scheduleMonitorTask() {
let request = BGAppRefreshTaskRequest(identifier: Self.monitorTaskId)
request.earliestBeginDate = Date(timeIntervalSinceNow: 30 * 60) // 30 minutes
do {
try BGTaskScheduler.shared.submit(request)
} catch {
print("Failed to schedule monitor task: \\(error)")
}
}
private func handleMonitorTask(_ task: BGAppRefreshTask) {
activeTasks.insert(task)
// Schedule next monitor
scheduleMonitorTask()
task.expirationHandler = {
task.setTaskCompleted(success: false)
self.activeTasks.remove(task)
}
// Quick monitor check
Task {
let hasUpdates = await performQuickMonitor()
if hasUpdates {
// Schedule immediate sync if needed
scheduleSyncTask()
}
task.setTaskCompleted(success: true)
self.activeTasks.remove(task)
}
}
private func performQuickMonitor() async -> Bool {
// Quick check for channel updates or payments
guard let lastBlockHeight = UserDefaults.standard.object(forKey: "lastBlockHeight") as? UInt32 else {
return true // Need sync
}
// Check current block height
let currentHeight = await getCurrentBlockHeight()
return currentHeight > lastBlockHeight + 6 // More than 1 hour of blocks
}
// MARK: - Maintenance Task
private func scheduleMaintenanceTask() {
let request = BGProcessingTaskRequest(identifier: Self.maintenanceTaskId)
request.requiresNetworkConnectivity = false
request.requiresExternalPower = false
request.earliestBeginDate = Date(timeIntervalSinceNow: 24 * 60 * 60) // Daily
do {
try BGTaskScheduler.shared.submit(request)
} catch {
print("Failed to schedule maintenance task: \\(error)")
}
}
private func handleMaintenanceTask(_ task: BGProcessingTask) {
activeTasks.insert(task)
// Schedule next maintenance
scheduleMaintenanceTask()
task.expirationHandler = {
task.setTaskCompleted(success: false)
self.activeTasks.remove(task)
}
// Perform maintenance
Task {
await performMaintenance()
task.setTaskCompleted(success: true)
self.activeTasks.remove(task)
}
}
private func performMaintenance() async {
// Clean up old data
cleanupOldPayments()
// Compact database
compactPersistentStorage()
// Prune network graph
pruneNetworkGraph()
// Backup critical data
await performBackup()
}
// MARK: - Helpers
private func checkIncomingPayments() async -> [Payment] {
// Check for new payments since last check
let lastCheck = UserDefaults.standard.object(forKey: "lastPaymentCheck") as? Date ?? Date.distantPast
let payments = await LDKManager.shared.getPaymentsSince(date: lastCheck)
UserDefaults.standard.set(Date(), forKey: "lastPaymentCheck")
return payments.filter { $0.direction == .inbound }
}
private func notifyPaymentsReceived(_ payments: [Payment]) {
for payment in payments {
LightningNotificationService.notifyPaymentReceived(
amountMsat: UInt64(payment.amountMsat),
description: payment.description
)
}
}
private func cancelSync() {
// Cancel ongoing sync operations
LDKManager.shared.cancelSync()
}
private func cleanupOldPayments() {
// Remove payments older than 90 days
let cutoffDate = Date().addingTimeInterval(-90 * 24 * 60 * 60)
PaymentStore.shared.deletePaymentsBefore(date: cutoffDate)
}
private func compactPersistentStorage() {
// Compact LDK persistent storage
LDKManager.shared.compactStorage()
}
private func pruneNetworkGraph() {
// Remove old network graph data
let networkGraph = LDKManager.shared.networkGraph
let currentTime = UInt64(Date().timeIntervalSince1970)
networkGraph.removeStaleChannels(currentUnixTimestamp: currentTime)
}
private func performBackup() async {
do {
let backup = try await LDKManager.shared.createBackup()
try await BackupManager.shared.saveToICloud(backup)
} catch {
print("Backup failed: \\(error)")
}
}
private func getCurrentBlockHeight() async -> UInt32 {
// Fetch from your block source
return 800000 // Placeholder
}
}
// App Delegate Integration
extension AppDelegate {
func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
// Register background tasks
LightningBackgroundTaskManager.shared.registerBackgroundTasks()
// Schedule initial tasks
LightningBackgroundTaskManager.shared.scheduleBackgroundTasks()
return true
}
func applicationDidEnterBackground(_ application: UIApplication) {
// Schedule background tasks when entering background
LightningBackgroundTaskManager.shared.scheduleBackgroundTasks()
}
}`.trim()
};
try {
const code = codeExamples[args.operation];
if (!code) {
throw new Error(`Unknown operation: ${args.operation}`);
}
return {
content: [{
type: 'text',
text: JSON.stringify({
success: true,
operation: args.operation,
swiftCode: code
}, null, 2)
}]
};
} catch (error) {
return {
content: [{
type: 'text',
text: JSON.stringify({
success: false,
error: error instanceof Error ? error.message : 'Unknown error'
}, null, 2)
}],
isError: true
};
}
}
};