LDK MCP Server

Instructions

Input Schema

Input Schema (JSON Schema)

Implementation Reference

• src/tools/generateMnemonic.ts:26-293 (handler)

  The execute function implementing the core logic of the 'ldk_generate_mnemonic' tool: processes input args, generates mnemonic and seed via WalletService, and returns structured JSON with Swift iOS integration example.
  execute: async (args: any): Promise<ToolResult> => { try { // Convert wordCount to strength if provided let strength = args.strength; if (args.wordCount) { strength = args.wordCount === 12 ? 128 : 256; } const mnemonic = walletService.generateMnemonic(strength || 256); const seedBuffer = walletService.mnemonicToSeed(mnemonic); const wordCount = mnemonic.split(' ').length; return { content: [{ type: 'text', text: JSON.stringify({ success: true, mnemonic, wordCount, seed: seedBuffer.toString('hex'), swiftExample: ` // Swift code for secure mnemonic generation in your iOS app import SwiftUI import CryptoKit import LightningDevKit class MnemonicGenerator { enum MnemonicLength: Int { case words12 = 128 case words24 = 256 var wordCount: Int { switch self { case .words12: return 12 case .words24: return 24 } } } static func generateMnemonic(length: MnemonicLength = .words24) throws -> [String] { // Generate entropy let entropyBytes = length.rawValue / 8 var entropy = Data(count: entropyBytes) let result = entropy.withUnsafeMutableBytes { bytes in SecRandomCopyBytes(kSecRandomDefault, entropyBytes, bytes.baseAddress!) } guard result == errSecSuccess else { throw WalletError.entropyGenerationFailed } // Convert to mnemonic let mnemonic = Mnemonic.toMnemonic(entropy: [UInt8](entropy)) guard let words = mnemonic else { throw WalletError.mnemonicGenerationFailed } return words.components(separatedBy: " ") } static func mnemonicToSeed(words: [String], passphrase: String = "") -> Data { let mnemonic = words.joined(separator: " ") let seed = Mnemonic.toSeed(phrase: mnemonic, password: passphrase) return Data(seed) } } // SwiftUI view for secure mnemonic display struct MnemonicSetupView: View { @State private var mnemonicWords: [String] = [] @State private var currentStep: SetupStep = .generate @State private var verificationWords: Set<Int> = [] @State private var verificationInput: [Int: String] = [:] @State private var showError = false enum SetupStep { case generate case display case verify case complete } var body: some View { VStack(spacing: 0) { // Progress indicator ProgressBar(currentStep: currentStep) .padding() // Content Group { switch currentStep { case .generate: GenerateView(onGenerate: generateMnemonic) case .display: DisplayView(words: mnemonicWords, onContinue: { setupVerification() currentStep = .verify }) case .verify: VerifyView( words: mnemonicWords, verificationIndices: Array(verificationWords), verificationInput: $verificationInput, onVerify: verifyMnemonic ) case .complete: CompleteView() } } .padding() Spacer() } .navigationTitle("Wallet Setup") .navigationBarBackButtonHidden(currentStep != .generate) .alert("Verification Failed", isPresented: $showError) { Button("Try Again") { } } message: { Text("Please check the words and try again.") } } func generateMnemonic() { do { mnemonicWords = try MnemonicGenerator.generateMnemonic() currentStep = .display } catch { // Handle error } } func setupVerification() { // Select random words to verify verificationWords = Set((0..<mnemonicWords.count).shuffled().prefix(3)) verificationInput = [:] } func verifyMnemonic() { var allCorrect = true for index in verificationWords { let expectedWord = mnemonicWords[index] let inputWord = verificationInput[index]?.lowercased().trimmingCharacters(in: .whitespacesAndNewlines) if inputWord != expectedWord { allCorrect = false break } } if allCorrect { saveMnemonicSecurely() currentStep = .complete } else { showError = true } } func saveMnemonicSecurely() { // Save to keychain with biometric protection Task { do { let seed = MnemonicGenerator.mnemonicToSeed(words: mnemonicWords) _ = try await BiometricLightningAuth.protectSeedWithBiometrics(seed: seed) // Clear mnemonic from memory mnemonicWords = [] verificationInput = [:] } catch { // Handle error } } } } struct DisplayView: View { let words: [String] let onContinue: () -> Void @State private var hasScreenshot = false var body: some View { VStack(spacing: 24) { // Warning VStack(spacing: 12) { Image(systemName: "exclamationmark.triangle.fill") .font(.largeTitle) .foregroundColor(.orange) Text("Write Down Your Recovery Phrase") .font(.title2) .fontWeight(.semibold) Text("Write these words on paper. Never share them with anyone.") .font(.callout) .foregroundColor(.secondary) .multilineTextAlignment(.center) } // Mnemonic grid LazyVGrid(columns: [ GridItem(.flexible()), GridItem(.flexible()), GridItem(.flexible()) ], spacing: 12) { ForEach(Array(words.enumerated()), id: \\.offset) { index, word in WordCell(number: index + 1, word: word) } } .padding() .background(Color(UIColor.secondarySystemBackground)) .cornerRadius(12) // Screenshot warning Toggle("I have written down all words", isOn: $hasScreenshot) .toggleStyle(CheckboxToggleStyle()) Button(action: onContinue) { Text("Continue to Verification") .frame(maxWidth: .infinity) } .buttonStyle(.borderedProminent) .controlSize(.large) .disabled(!hasScreenshot) } } } struct WordCell: View { let number: Int let word: String var body: some View { HStack(spacing: 8) { Text("\\(number).") .font(.caption) .foregroundColor(.secondary) .frame(width: 20, alignment: .trailing) Text(word) .font(.system(.body, design: .monospaced)) .fontWeight(.medium) } .padding(.vertical, 8) .padding(.horizontal, 12) .frame(maxWidth: .infinity, alignment: .leading) .background(Color(UIColor.tertiarySystemBackground)) .cornerRadius(8) } }`.trim() }, 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 }; } }
• src/tools/generateMnemonic.ts:9-25 (schema)

  Input schema for the tool defining optional parameters for mnemonic strength or word count.
  inputSchema: { type: 'object', properties: { strength: { type: 'number', enum: [128, 256], description: 'Mnemonic strength (128 = 12 words, 256 = 24 words)', default: 256 }, wordCount: { type: 'number', enum: [12, 24], description: 'Number of words in mnemonic (12 or 24)', default: 24 } } },
• src/index.ts:38-62 (registration)

  Registration of the generateMnemonicTool in the central tools array used by the MCP server for tool discovery and execution dispatching.
  const tools = [ generateInvoiceTool, payInvoiceTool, getChannelStatusTool, getNodeInfoTool, backupStateTool, keychainTestTool, backgroundTestTool, pushNotificationTool, biometricAuthTool, createChannelTool, closeChannelTool, getBalanceTool, decodeInvoiceTool, listPaymentsTool, estimateFeeTool, generateMnemonicTool, deriveAddressTool, getSwiftCodeTool, getArchitectureTool, testScenarioTool, networkGraphTool, eventHandlingTool, chainSyncTool, ];
• src/services/walletService.ts:19-21 (helper)

  Supporting WalletService method that generates the BIP39 mnemonic phrase using the bip39 library, called by the tool handler.
  generateMnemonic(strength: 128 | 256 = 256): string { return bip39.generateMnemonic(strength); }