// Manual polling — you call pollUntilComplete() yourself, no background threads
PortalClient client = new PortalClient(
    PortalClientConfig.create("http://localhost:3000", "token")
);

// Auto-polling — background scheduler, just use done()
PortalClient client = new PortalClient(
    PortalClientConfig.create("http://localhost:3000", "token")
        .autoPolling(500) // poll every 500ms
);

// Webhooks — portal-rest POSTs to your server, just use done()
PortalClient client = new PortalClient(
    PortalClientConfig.create("http://localhost:3000", "token")
        .webhookSecret("my-secret")
);

AsyncOperation<InvoiceStatus> op = client.requestSinglePayment(
    mainKey, List.of(),
    new SinglePaymentRequestContent("Coffee", 1000, Currency.MILLISATS, null, null, null)
);

// blocks until paid/rejected/timeout
InvoiceStatus result = client.pollUntilComplete(op, PollOptions.defaults().timeoutMs(60_000));
System.out.println(result.status); // "paid", "timeout", "user_rejected", ...

// client configured with .autoPolling(500)
AsyncOperation<InvoiceStatus> op = client.requestSinglePayment(...);
op.done().thenAccept(result -> System.out.println(result.status));

// client configured with .webhookSecret("my-secret")
AsyncOperation<InvoiceStatus> op = client.requestSinglePayment(...);
op.done().thenAccept(result -> System.out.println(result.status));

// in your HTTP server's POST /webhook handler:
client.deliverWebhookPayload(rawBody, request.getHeader("X-Portal-Signature"));