Lightning Tools MCP Server

Instructions

Implementation Reference

• src/tools/request_invoice.ts:26-46 (handler)

  The handler function that executes the tool: creates a LightningAddress from the input, fetches LNURL data, requests an invoice with the given amount, description, and payer data, then returns the invoice as JSON text content.

  async (params) => {
    const ln = new LightningAddress(params.lightning_address);
  
    // fetch the LNURL data
    await ln.fetch();
  
    const invoice = await ln.requestInvoice({
      satoshi: params.amount,
      comment: params.description || undefined,
      payerdata: params.payer_data || undefined,
    });
  
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(invoice, null, 2),
        },
      ],
    };
  }

• src/tools/request_invoice.ts:9-25 (schema)

  Zod schema defining the input parameters: lightning_address (string), amount (number in sats), optional description (string), optional payer_data (object).

  {
    lightning_address: z
      .string()
      .describe("the recipient's lightning address"),
    amount: z.number().describe("amount in sats"),
    description: z
      .string()
      .describe("note, memo or description describing the invoice")
      .nullish(),
    payer_data: z
      .object({})
      .passthrough()
      .describe(
        "metadata to include with the payment such as the payer's name"
      )
      .nullish(),
  },

• src/tools/request_invoice.ts:5-48 (registration)

  The registerRequestInvoiceTool function that registers the "request_invoice" tool on the MCP server using server.tool with name, description, input schema, and handler.

  export function registerRequestInvoiceTool(server: McpServer) {
    server.tool(
      "request_invoice",
      "Request an invoice from a lightning address",
      {
        lightning_address: z
          .string()
          .describe("the recipient's lightning address"),
        amount: z.number().describe("amount in sats"),
        description: z
          .string()
          .describe("note, memo or description describing the invoice")
          .nullish(),
        payer_data: z
          .object({})
          .passthrough()
          .describe(
            "metadata to include with the payment such as the payer's name"
          )
          .nullish(),
      },
      async (params) => {
        const ln = new LightningAddress(params.lightning_address);
  
        // fetch the LNURL data
        await ln.fetch();
  
        const invoice = await ln.requestInvoice({
          satoshi: params.amount,
          comment: params.description || undefined,
          payerdata: params.payer_data || undefined,
        });
  
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(invoice, null, 2),
            },
          ],
        };
      }
    );
  }

• src/index.ts:28-28 (registration)

  Invocation of the registerRequestInvoiceTool function in the main server constructor to add the tool to the MCP server instance.

  registerRequestInvoiceTool(this._server);