> For the complete documentation index, see [llms.txt](https://docs.lmms.io/developer-guides/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lmms.io/developer-guides/core/the-structure-of-the-lmms-core/accessing-to-core-classes.md).

# Accessing to core classes

Class `Engine` provides access to some core classes of LMMS. Here's an example:

```cpp
#include "Engine.h"

void foo()
{
	bpm_t tempo = Engine::getSong()->getTempo();
	int CPULoad = Engine::audioEngine()->cpuLoad();
}
```