diff --git a/.gitignore b/.gitignore
index 4c1f3b5..1eecd6e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ php/psalm.xml
 php/vendor
 
 php.log
+config.json
diff --git a/config.default.json b/config.default.json
new file mode 100644
index 0000000..64d8bab
--- /dev/null
+++ b/config.default.json
@@ -0,0 +1,6 @@
+{
+	"ROOT_URL": "http://localhost/",
+	"ROOT_DIR": "/var/www/html/",
+	"IMG_DIR": "img/",
+	"THUMBNAIL_DIR": "thumbnails/"
+}
diff --git a/php/get.php b/php/get.php
index e322614..3bdd069 100644
--- a/php/get.php
+++ b/php/get.php
@@ -3,10 +3,11 @@ include_once __DIR__ . "/logging.php";
 include_once __DIR__ . "/cors.php";
 cors();
 
-define("ROOT_URL", "http://localhost/");
-define("ROOT_DIR", "/var/www/localhost/");
-define("IMG_DIR", "img/");
-define("THUMBNAIL_DIR", "thumbnails/");
+$config_data = get_config();
+define("ROOT_URL", $config_data["ROOT_URL"]);
+define("ROOT_DIR", $config_data["ROOT_DIR"]);
+define("IMG_DIR", $config_data["IMG_DIR"]);
+define("THUMBNAIL_DIR", $config_data["THUMBNAIL_DIR"]);
 define("THUMBNAIL_SCRIPT", __DIR__ . "/../scripts/resize-img");
 
 define("IMAGE_EXTENSIONS", [
@@ -116,5 +117,40 @@ function is_image_file_type(string $filename): bool {
 	return false;
 }
 
+function get_config(): array {
+	$config_data = file_exists(__DIR__ . "/../config.json") ?
+		json_decode(file_get_contents(__DIR__ . "/../config.json"), true) : null;
+
+	if (!is_valid_config_data($config_data)) {
+		log_error("Config invalid, falling back to default. Please check config.json");
+
+		$config_data = json_decode(file_get_contents(__DIR__ . "/../config.default.json"), true);
+		if (!is_valid_config_data($config_data))
+			log_error("Default config invalid. Please check or create config.json");
+	}
+	return $config_data;
+}
+
+
+function is_valid_config_data(?array $data): bool {
+	if (!$data) return false;
+	$keys = ["ROOT_URL", "ROOT_DIR", "IMG_DIR", "THUMBNAIL_DIR"];
+	foreach ($keys as $key) {
+		if (!isset($data[$key])) return false;
+		switch ($key) {
+		case "ROOT_URL":
+		case "THUMBNAIL_DIR":
+			break;
+		case "ROOT_DIR":
+			if (!is_dir($data[$key])) return false;
+			break;
+		case "IMG_DIR":
+			if (!is_dir($data["ROOT_DIR"].$data[$key])) return false;
+			break;
+		}
+	}
+	return true;
+}
+
 main();
 ?>