@getalby/mcp/build/tools/nwc/pay_invoice.js

MCP server for controlling a Lightning wallet using Nostr Wallet Connect

import { z } from "zod";
export function registerPayInvoiceTool(server, client) {
    server.registerTool("pay_invoice", {
        title: "Pay Invoice",
        description: "Pay a lightning invoice",
        inputSchema: {
            invoice: z.string().describe("The lightning invoice to pay"),
            amount_in_sats: z
                .number()
                .describe("Optional amount in sats, only provide if paying a zero-amount invoice")
                .nullish(),
            metadata: z
                .object({})
                .passthrough()
                .describe("Optional metadata to include with the payment")
                .nullish(),
        },
        outputSchema: {
            preimage: z.string().describe("Payment preimage"),
            fees_paid_in_sats: z.number().nullish().describe("Fees paid in sats"), // TODO: remove nullish once Primal supports it
        },
    }, async (params) => {
        const { fees_paid, preimage, ...result } = await client.payInvoice({
            invoice: params.invoice,
            amount: params.amount_in_sats
                ? params.amount_in_sats * 1000
                : undefined, // Convert sats to millisats for NWC
            metadata: params.metadata || undefined,
        });
        // Convert millisats back to sats in the response
        const convertedResult = {
            ...result,
            preimage: preimage || "", // TODO: once Primal supports preimage, remove this
            fees_paid_in_sats: typeof fees_paid === "number"
                ? Math.ceil(fees_paid / 1000) // Round up fees when converting millisats to sats
                : undefined,
        };
        return {
            content: [
                {
                    type: "text",
                    text: JSON.stringify(convertedResult, null, 2),
                },
            ],
            structuredContent: convertedResult,
        };
    });
}