store-routing-credentials

Instructions

Implementation Reference

• src/tools/store-credentials.ts:10-30 (handler)

  Handler function that stores L402 payment credentials (macaroon + preimage) on the RoutingClient instance after a user pays a Lightning invoice.

  export async function handleStoreRoutingCredentials(
    args: {
      macaroon: string
      preimage: string
    },
    routingClient: RoutingClient,
  ) {
    console.error('Storing L402 routing credentials')
  
    routingClient.storeL402Credentials(args.macaroon, args.preimage)
  
    return {
      content: [{
        type: 'text' as const,
        text: JSON.stringify({
          success: true,
          message: 'L402 credentials stored. Subsequent routing calls will authenticate automatically.',
        }),
      }],
    }
  }

• src/tools/store-credentials.ts:45-51 (schema)

  Input schema using Zod validation: 'macaroon' (base64 string, 1-4096 chars) and 'preimage' (hex string, 1-128 chars), with idempotent annotation.

  inputSchema: {
    macaroon: z.string().min(1).max(4096).regex(/^[A-Za-z0-9+/=]+$/, 'Must be valid base64')
      .describe('The macaroon from the payment_required response'),
    preimage: z.string().min(1).max(128).regex(/^[0-9a-fA-F]+$/, 'Must be valid hex')
      .describe('The payment preimage obtained after paying the invoice'),
  },
  annotations: { readOnlyHint: false, idempotentHint: true },

• src/tools/store-credentials.ts:36-55 (registration)

  Registers the 'store-routing-credentials' tool with the MCP server, wiring the Zod schema and handler.

  export function registerStoreCredentialsTool(server: McpServer, routingClient: RoutingClient): void {
    server.registerTool(
      'store-routing-credentials',
      {
        description:
          'Store L402 payment credentials (macaroon + preimage) after paying a routing invoice. ' +
          'Call this after the user has paid the Lightning invoice returned by a payment_required response. ' +
          'Once stored, all subsequent routing calls (score-venues, get-isochrone, get-directions) ' +
          'will authenticate automatically.',
        inputSchema: {
          macaroon: z.string().min(1).max(4096).regex(/^[A-Za-z0-9+/=]+$/, 'Must be valid base64')
            .describe('The macaroon from the payment_required response'),
          preimage: z.string().min(1).max(128).regex(/^[0-9a-fA-F]+$/, 'Must be valid hex')
            .describe('The payment preimage obtained after paying the invoice'),
        },
        annotations: { readOnlyHint: false, idempotentHint: true },
      },
      async (args) => handleStoreRoutingCredentials(args, routingClient),
    )
  }

• src/index.ts:44-44 (registration)

  Main entry point where the store-credentials tool is registered via registerStoreCredentialsTool.

  registerStoreCredentialsTool(server, routingClient)

• src/routing.ts:32-34 (helper)

  RoutingClient method that delegates to L402State.store() to persist the macaroon and preimage in memory.

  storeL402Credentials(macaroon: string, preimage: string): void {
    this.l402.store(macaroon, preimage)
  }