# <PROJECT-NAME>_IS_TOP_LEVEL

New in version 3.21.

A boolean variable indicating whether the named project was called in a top level `CMakeLists.txt` file.

To obtain the value from the most recent call to `project()` in the current directory scope or above, see the `PROJECT_IS_TOP_LEVEL` variable.

The variable value will be true in:

- the top-level directory of the project

- the top-level directory of an external project added by `ExternalProject`

The variable value will be false in:

- a directory added by `add_subdirectory()`

- a directory added by `FetchContent`