diff --git a/Cargo.toml b/Cargo.toml
index 43b3dab..b2920b4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,6 +32,10 @@ name = "rust4d"
 version = "0.1.0"
 edition = "2021"
 
+[lib]
+name = "rust4d"
+path = "src/lib.rs"
+
 [[bin]]
 name = "rust4d"
 path = "src/main.rs"
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..711814e
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,5 @@
+//! Rust4D - 4D Rendering Engine
+//!
+//! This library module exports the configuration system for integration tests.
+
+pub mod config;
diff --git a/src/main.rs b/src/main.rs
index d4c0e35..1dc0ccf 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -326,35 +326,3 @@ fn main() {
     let mut app = App::new();
     event_loop.run_app(&mut app).expect("Event loop error");
 }
-
-#[cfg(test)]
-mod integration_tests {
-    use super::config::AppConfig;
-    use serial_test::serial;
-
-    #[test]
-    #[serial]
-    fn test_env_override() {
-        std::env::set_var("R4D_WINDOW__TITLE", "Test From Env");
-        let config = AppConfig::load().unwrap();
-        println!("Window title: {}", config.window.title);
-        assert_eq!(config.window.title, "Test From Env");
-        std::env::remove_var("R4D_WINDOW__TITLE");
-    }
-
-    #[test]
-    #[serial]
-    fn test_user_config_loading() {
-        // Remove env var to test file-based config
-        std::env::remove_var("R4D_WINDOW__TITLE");
-
-        // Debug: print current dir and check if files exist
-        let cwd = std::env::current_dir().unwrap();
-        println!("Current dir: {:?}", cwd);
-        println!("config/default.toml exists: {}", cwd.join("config/default.toml").exists());
-        println!("config/user.toml exists: {}", cwd.join("config/user.toml").exists());
-
-        let config = AppConfig::load().unwrap();
-        println!("Window title from file: {}", config.window.title);
-    }
-}
diff --git a/tests/config_integration.rs b/tests/config_integration.rs
new file mode 100644
index 0000000..857d01b
--- /dev/null
+++ b/tests/config_integration.rs
@@ -0,0 +1,38 @@
+//! Integration tests for configuration loading
+//!
+//! Tests that verify config loading from files and environment variables.
+
+use rust4d::config::AppConfig;
+use serial_test::serial;
+
+#[test]
+#[serial]
+fn test_env_override() {
+    std::env::set_var("R4D_WINDOW__TITLE", "Test From Env");
+    let config = AppConfig::load().unwrap();
+    println!("Window title: {}", config.window.title);
+    assert_eq!(config.window.title, "Test From Env");
+    std::env::remove_var("R4D_WINDOW__TITLE");
+}
+
+#[test]
+#[serial]
+fn test_user_config_loading() {
+    // Remove env var to test file-based config
+    std::env::remove_var("R4D_WINDOW__TITLE");
+
+    // Debug: print current dir and check if files exist
+    let cwd = std::env::current_dir().unwrap();
+    println!("Current dir: {:?}", cwd);
+    println!(
+        "config/default.toml exists: {}",
+        cwd.join("config/default.toml").exists()
+    );
+    println!(
+        "config/user.toml exists: {}",
+        cwd.join("config/user.toml").exists()
+    );
+
+    let config = AppConfig::load().unwrap();
+    println!("Window title from file: {}", config.window.title);
+}