LDK MCP Server

Instructions

Implementation Reference

• src/tools/getChannelStatus.ts:19-236 (handler)

  Main execution logic for the ldk_channel_status tool: fetches channels from LightningService, filters offline channels if requested, computes balance summaries, formats response with channel details and SwiftUI example code.
  execute: async (args: any): Promise<ToolResult> => { try { const channels = await lightningService.getChannelStatus(); const filteredChannels = args.includeOffline === false ? channels.filter(c => c.isUsable) : channels; const totalCapacity = channels.reduce((sum, c) => sum + c.capacityMsat, 0); const totalLocal = channels.reduce((sum, c) => sum + c.localBalanceMsat, 0); const totalRemote = channels.reduce((sum, c) => sum + c.remoteBalanceMsat, 0); return { content: [{ type: 'text', text: JSON.stringify({ success: true, summary: { totalChannels: channels.length, usableChannels: channels.filter(c => c.isUsable).length, totalCapacitySats: Math.floor(totalCapacity / 1000), totalLocalSats: Math.floor(totalLocal / 1000), totalRemoteSats: Math.floor(totalRemote / 1000) }, channels: filteredChannels.map(c => ({ channelId: c.channelId, shortChannelId: c.shortChannelId, remotePubkey: c.remotePubkey, state: c.state, isUsable: c.isUsable, capacitySats: Math.floor(c.capacityMsat / 1000), localBalanceSats: Math.floor(c.localBalanceMsat / 1000), remoteBalanceSats: Math.floor(c.remoteBalanceMsat / 1000) })), swiftExample: ` // Swift code to display channel status in your iOS app import SwiftUI import LightningDevKit struct ChannelListView: View { @State private var channels: [ChannelDetails] = [] @State private var isLoading = true var body: some View { NavigationView { List { // Summary Section Section("Summary") { HStack { Label("Total Capacity", systemImage: "bolt.circle") Spacer() Text("\\(totalCapacitySats) sats") .foregroundColor(.secondary) } HStack { Label("Local Balance", systemImage: "arrow.up.circle") .foregroundColor(.green) Spacer() Text("\\(totalLocalSats) sats") .foregroundColor(.secondary) } HStack { Label("Remote Balance", systemImage: "arrow.down.circle") .foregroundColor(.blue) Spacer() Text("\\(totalRemoteSats) sats") .foregroundColor(.secondary) } } // Channels Section Section("Channels (\\(usableChannels)/\\(channels.count))") { ForEach(channels, id: \\.channelId) { channel in ChannelRow(channel: channel) } } } .navigationTitle("Lightning Channels") .refreshable { await loadChannels() } .overlay { if isLoading { ProgressView() } } } .task { await loadChannels() } } var totalCapacitySats: Int { channels.reduce(0) { $0 + Int($1.channelValueSatoshis) } } var totalLocalSats: Int { channels.reduce(0) { $0 + Int($1.balanceMsat / 1000) } } var totalRemoteSats: Int { channels.reduce(0) { total, channel in total + Int(channel.channelValueSatoshis) - Int(channel.balanceMsat / 1000) } } var usableChannels: Int { channels.filter { $0.isUsable }.count } func loadChannels() async { isLoading = true defer { isLoading = false } // Get channels from LDK let channelManager = LDKManager.shared.channelManager channels = channelManager.listChannels() } } struct ChannelRow: View { let channel: ChannelDetails var body: some View { VStack(alignment: .leading, spacing: 8) { // Channel state indicator HStack { Circle() .fill(channel.isUsable ? Color.green : Color.orange) .frame(width: 10, height: 10) Text(channelStateText) .font(.caption) .foregroundColor(.secondary) Spacer() if let scid = channel.getShortChannelId() { Text(scid.description) .font(.caption2) .foregroundColor(.secondary) } } // Balance bar GeometryReader { geometry in ZStack(alignment: .leading) { // Background RoundedRectangle(cornerRadius: 4) .fill(Color.gray.opacity(0.2)) .frame(height: 20) // Local balance RoundedRectangle(cornerRadius: 4) .fill(Color.green) .frame( width: geometry.size.width * localBalanceRatio, height: 20 ) } } .frame(height: 20) // Balance text HStack { Text("\\(localBalanceSats) sats") .font(.caption) .foregroundColor(.green) Spacer() Text("\\(remoteBalanceSats) sats") .font(.caption) .foregroundColor(.blue) } } .padding(.vertical, 4) } var channelStateText: String { if channel.isUsable { return "Active" } else if channel.isChannelReady { return "Ready" } else { return "Pending" } } var localBalanceSats: Int { Int(channel.balanceMsat / 1000) } var remoteBalanceSats: Int { Int(channel.channelValueSatoshis) - localBalanceSats } var localBalanceRatio: Double { Double(channel.balanceMsat) / Double(channel.channelValueSatoshis * 1000) } }`.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/getChannelStatus.ts:9-18 (schema)

  Input schema defining optional 'includeOffline' boolean parameter for the tool.
  inputSchema: { type: 'object', properties: { includeOffline: { type: 'boolean', description: 'Include offline/unusable channels', default: true } } },
• src/index.ts:38-62 (registration)

  Registration of all tools including getChannelStatusTool in the central tools array used by MCP server handlers.
  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/lightningService.ts:168-170 (helper)

  Helper method in LightningService that provides the raw list of channels, invoked by the tool handler.
  async getChannelStatus(): Promise<Channel[]> { return Array.from(this.channels.values()); }