@getalby/paidmcp/build/callbacks.js

Charge for your MCP Server tools using Nostr Wallet Connect

export function paidCallback(cb, charge, wallet, storage) {
    return async (args, extra) => {
        if (!args.payment_hash ||
            !(await storage.isValid(args.payment_hash)) ||
            !(await wallet.verifyPayment(args.payment_hash))) {
            const chargeArgs = await charge(args);
            const { payment_request, payment_hash } = await wallet.requestInvoice({
                satoshi: chargeArgs.satoshi,
                description: chargeArgs.description,
            });
            await storage.setValid(payment_hash, true);
            const result = {
                payment_instructions: "Payment required. Pay the payment_request and try the same request again with the payment_hash set to continue.",
                payment_request,
                payment_hash,
            };
            return {
                content: [
                    {
                        type: "text",
                        text: JSON.stringify(result),
                    },
                ],
                structuredContent: result,
            };
        }
        // only allow one request per payment
        await storage.setValid(args.payment_hash, false);
        return cb(args, extra);
    };
}