diff --git a/flake.nix b/flake.nix
index f768299..b60af57 100644
--- a/flake.nix
+++ b/flake.nix
@@ -9,6 +9,30 @@
       system = "x86_64-linux";
     };
   in {
+    packages.x86_64-linux = {
+      # Define the default package, which will build the C++ app
+      default = pkgs.stdenv.mkDerivation {
+        pname = "cli";
+        version = "0.1.0";
+
+        # Source directory containing the C++ code
+        src = ./.;
+
+        # Build dependencies (e.g., compilers)
+        buildInputs = [ pkgs.gcc pkgs.libusb1 ];
+
+        # Build commands
+        buildPhase = ''
+          mkdir -p $out/bin
+          g++ -o $out/bin/cli src/cli.cpp src/usb_thingy.cpp -lusb-1.0
+        '';
+
+        # Optional: installation phase, if additional steps are needed
+        #installPhase = ''
+        #  # Nothing extra needed here; the binary is already in $out/bin
+        #'';
+      };
+    };
     devShells.x86_64-linux = {
       default = pkgs.mkShell {
         propagatedBuildInputs = with pkgs; [
diff --git a/src/cli.cpp b/src/cli.cpp
index 5b96fec..f3c32c3 100644
--- a/src/cli.cpp
+++ b/src/cli.cpp
@@ -1 +1,116 @@
-#include <usb_thingy.h>
\ No newline at end of file
+#include "usb_thingy.h"
+
+#include <getopt.h>
+#include <iostream>
+#include <string.h>
+
+#define CHK(X)          \
+    if ((r = (X)) != 0) \
+        return r;
+
+int main(int argc, char *argv[])
+{
+    // Define the long options
+    static struct option long_options[] = {
+        {"help", no_argument, nullptr, 'h'},
+        {"battery-capacity", no_argument, nullptr, 'c'},
+        {"battery-status", no_argument, nullptr, 's'},
+        {nullptr, 0, nullptr, 0}};
+
+    /*static struct option long_options[] = {
+        {"help", no_argument, nullptr, 'h'},
+        {"battery-capacity", no_argument, nullptr, 'c'},
+        {"battery-status", required_argument, nullptr, 's'},
+        {nullptr, 0, nullptr, 0}
+    };*/
+
+    int option_index = 0;
+    int opt;
+    bool getBatteryStatus = false;
+    bool getBatteryCapacity = false;
+
+    if (Connection::getInstance().findDevice())
+    {
+        std::cerr << "ERROR: Device not found!";
+        return 1;
+    }
+
+    // Parse command-line arguments
+    while ((opt = getopt_long(argc, argv, "hcs:", long_options, &option_index)) != -1)
+    {
+        switch (opt)
+        {
+        case 'h':
+            std::cout << "Usage: " << argv[0] << " [options]\n"
+                      << "Options:\n"
+                      << "  -h, --help              Show this help message\n"
+                      << "  -c, --battery-capacity  Print battery capacity\n"
+                      << "  -s, --battery-status    Print battery status\n";
+            return 0;
+        case 'c':
+            getBatteryCapacity = true;
+            break;
+        case 's':
+            getBatteryStatus = true;
+            break;
+        case '?': // Handle unknown options
+            std::cerr << "Unknown option. Use --help to see the usage.\n";
+            return 1;
+        default:
+            break;
+        }
+    }
+
+    // Display the parsed arguments
+    if (getBatteryCapacity)
+    {
+        unsigned char dat[8];
+        memset(dat, 0, 8 * sizeof(unsigned char));
+
+        unsigned char _data[8] = {0x05, 0x90, 0, 0, 0, 0, 0, 0};
+
+        ssize_t r;
+        CHK(Connection::getInstance().open());
+        CHK(Connection::getInstance().setReport(0x0305, (unsigned char *)_data, 8));
+        CHK(Connection::getInstance().getReport(0x0305, (unsigned char *)dat, 8));
+        CHK(Connection::getInstance().close());
+
+        if (dat[2] == 0x10 && dat[3] == 0x01)
+            return -1;
+
+        std::cout << (int)dat[3] << "\n";
+        return 0;
+    }
+    if (getBatteryStatus)
+    {
+        unsigned char dat[8];
+        memset(dat, 0, 8 * sizeof(unsigned char));
+
+        unsigned char _data[8] = {0x05, 0x90, 0, 0, 0, 0, 0, 0};
+
+        ssize_t r;
+        CHK(Connection::getInstance().open());
+        CHK(Connection::getInstance().setReport(0x0305, (unsigned char *)_data, 8));
+        CHK(Connection::getInstance().getReport(0x0305, (unsigned char *)dat, 8));
+        CHK(Connection::getInstance().close());
+
+        if (dat[2] == 0x10 && dat[3] == 0x01)
+        {
+            std::cout << "loading"
+                      << "\n";
+            return 0;
+        }
+
+        std::cout << "discharging"
+                  << "\n";
+        return 0;
+    }
+
+    // Handle non-option arguments
+    for (int i = optind; i < argc; i++)
+    {
+        std::cout << "Non-option argument: " << argv[i] << "\n";
+    }
+
+    return 0;
+}
\ No newline at end of file