diff --git a/source.cpp b/source.cpp
new file mode 100644
index 0000000..8b73422
--- /dev/null
+++ b/source.cpp
@@ -0,0 +1,121 @@
+#include <string>
+#include <regex>
+#include <array>
+#include <set>
+#include <cstdio>
+#include <memory>
+#include <iostream>
+#include "picojson.h"
+
+using namespace std;
+
+/* Get output from subprocess */
+string exec(const char * cmd) {
+    array<char, 128> buffer;
+    string result;
+    unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd, "r"), pclose);
+    if (!pipe) { 
+        cerr << "popen() failed!" << '\n';
+    }
+    while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
+        result += buffer.data();
+    }
+    return result;
+}
+
+/* Get env var */
+string get_env_var(const char * varname, string fallback = "") {
+    string result;
+    char * val = getenv(varname);
+    if (val == NULL) {
+        result = fallback;
+    } else {
+        result = val;
+    }
+    return result;
+}
+
+int main() {
+    
+    /* Get SwitchAudioSource path from env var */
+    string cmd = get_env_var("CMDPATH", "/usr/local/bin/SwitchAudioSource");
+    string tmp = cmd + " -af json";
+    const char * json_cmd = tmp.c_str();
+    cmd.append(" -cf cli -t ");
+    string tmp1 = cmd + "input";
+    const char * current_input_cmd = tmp1.c_str();
+    string tmp2 = cmd + "output";
+    const char * current_output_cmd = tmp2.c_str();
+    
+    /* Get currently selected device ids */
+    string raw_current_output = exec(current_input_cmd);
+    string raw_current_input = exec(current_output_cmd);
+    smatch current_output_id;
+    smatch current_input_id;
+    regex rgx("[0-9]{2}");
+    if (!regex_search(raw_current_output, current_output_id, rgx)) {
+        cerr << "current output id not found" << '\n';
+        exit(1);
+    }
+    if (!regex_search(raw_current_input, current_input_id, rgx)) {
+        cerr << "current input id not found" << '\n';
+        exit(1);
+    }
+    set<string> current_devices = {current_output_id[0], current_input_id[0]};
+    
+    /* Parse SwitchAudioSource JSON */
+    string json = regex_replace(exec(json_cmd), regex("\n"), ",");
+    json.pop_back();
+    json.insert(0, "[");
+    json.append("]");
+    picojson::value v;
+    string err = picojson::parse(v, json);
+    if (!err.empty()) {
+        cerr << err << '\n';
+        exit(2);
+    }
+    if (!v.is<picojson::array>()) {
+        cerr << "JSON is not an array" << '\n';
+        exit(3);
+    }
+    
+    /* Construct script filter JSON */
+    picojson::object result;
+    picojson::array items;
+    const picojson::value::array& devices = v.get<picojson::array>();
+    for (picojson::value::array::const_reverse_iterator i = devices.rbegin(); i != devices.rend(); ++i) {
+        
+        const picojson::value::object& device = (*i).get<picojson::object>();
+        string name = device.at("name").get<string>();
+        string nozoom = get_env_var("NOZOOM");        
+        if (nozoom == "true" && name == "ZoomAudioDevice") {
+            continue;
+        }
+        string id = device.at("id").get<string>();
+        string type = device.at("type").get<string>();
+        picojson::object item;
+        picojson::object variables;
+        picojson::object icon;
+        
+        if (current_devices.contains(id)) {
+            item["title"] = picojson::value("\u25c9   "+name);
+            variables["selected"] = picojson::value("true");
+            
+        } else {
+            item["title"] = picojson::value("\u25cb   "+name);
+            variables["selected"] = picojson::value("false");
+        }
+        variables["type"] = picojson::value(type);
+        icon["path"] = picojson::value(type+".icns");
+        item["arg"] = picojson::value(name);
+        item["icon"] = picojson::value(icon);
+        item["variables"] = picojson::value(variables);
+        
+        items.push_back(picojson::value(item));
+    }
+    
+    result["items"] = picojson::value(items);
+    cout << picojson::value(result) << '\n';
+    
+    return 0;
+}