diff --git a/src/patrix/core/Config.h b/src/patrix/core/Config.h
index b60e853..d15a746 100644
--- a/src/patrix/core/Config.h
+++ b/src/patrix/core/Config.h
@@ -15,14 +15,14 @@ class Config final {
 
   const String path;
 
-  JsonDocument config;
-
   unsigned long dirty = 0;
 
   bool doForceNextHexBuffer = true;
 
 public:
 
+  JsonDocument json;
+
   explicit Config(String path) : path(std::move(path)) {
     //
   }
@@ -37,8 +37,8 @@ public:
       return;
     }
     if (!deserialize(file)) {
-      config.clear();
-      config = config.to<JsonObject>();
+      json.clear();
+      json = json.to<JsonObject>();
     }
     file.close();
   }
@@ -50,10 +50,10 @@ public:
       error("Failed to open file for config write: %s", path.c_str());
       return;
     }
-    const auto size = measureJson(config);
-    if (serializeJson(config, write) == size) {
+    const auto size = measureJson(json);
+    if (serializeJson(json, write) == size) {
       char buffer[256];
-      serializeJson(config, buffer, sizeof buffer);
+      serializeJson(json, buffer, sizeof buffer);
       info("Config written: %s => %s", path.c_str(), buffer);
     } else {
       error("Failed to write config: %s", path.c_str());
@@ -68,19 +68,24 @@ public:
     }
   }
 
+  template<typename T>
+  bool has(const char *key) {
+    return json[key].is<T>();
+  }
+
   template<typename T>
   T get(const char *key, T fallback) {
-    if (config[key].is<T>()) {
-      return config[key].as<T>();
+    if (json[key].is<T>()) {
+      return json[key].as<T>();
     }
     warn("Config key \"%s\" not found!", key);
     return fallback;
   }
 
   bool setIfNot(const char *key, const int value) {
-    auto changed = !config[key].is<int>();
+    auto changed = !json[key].is<int>();
     if (!changed) {
-      changed = config[key].as<int>() != value;
+      changed = json[key].as<int>() != value;
     }
     if (changed) {
       set(key, value);
@@ -90,9 +95,9 @@ public:
   }
 
   bool setIfNot(const char *key, const double value) {
-    auto changed = !config[key].is<double>();
+    auto changed = !json[key].is<double>();
     if (!changed) {
-      changed = config[key].as<double>() != value;
+      changed = json[key].as<double>() != value;
     }
     if (changed) {
       set(key, value);
@@ -102,26 +107,44 @@ public:
   }
 
   template<typename T>
-  void set(const char *key, T value) {
-    config[key] = value;
-    dirty = max(1UL, millis()); // avoid special value zero (=> not dirty)
+  void set(const String& key, T value) {
+    json[key] = value;
+    dirty = millis();
+    if (dirty == 0) {
+      // avoid special value zero (=> not dirty)
+      dirty--;
+    }
+  }
+
+  unsigned long getAutoWriteInMillis() const {
+    if (dirty == 0) {
+      return 0;
+    }
+    return CONFIG_WRITE_DELAY_MILLIS - (millis() - dirty);
+  }
+
+  time_t getAutoWriteAtEpoch() const {
+    if (dirty == 0) {
+      return 0;
+    }
+    return time(nullptr) + static_cast<long>(getAutoWriteInMillis() / 1000);
   }
 
 private:
 
   bool deserialize(File file) {
-    if (deserializeJson(config, file) != DeserializationError::Ok) {
+    if (deserializeJson(json, file) != DeserializationError::Ok) {
       error("Failed to deserialize config: %s", file.path());
       return false;
     }
-    if (!config.is<JsonObject>()) {
+    if (!json.is<JsonObject>()) {
       error("Config not a json-object: %s", file.path());
       return false;
     }
     char buffer[256];
-    serializeJson(config, buffer, sizeof buffer);
+    serializeJson(json, buffer, sizeof buffer);
     info("Config loaded: %s => %s", path.c_str(), buffer);
-    config = config.as<JsonObject>();
+    json = json.as<JsonObject>();
     return true;
   }