Documentation › APP_REGISTRY

Application Registry

LeonOS 4 discovers runnable applications from package metadata instead of a compiled-in application path table. At boot image creation, the build system writes manifest.ini next to each staged executable:

[app]
id=notepad
name=Notepad
version=system
category=Desktop applications
exec=notepad.elf
icon=notepad.bmp
entry=1
terminal=0
system=1
hidden=0
open_with=1
extensions=.txt,.md,.log
commands=notepad

exec and icon are package-relative paths. The runtime rejects paths that escape the package directory. Older <package>.app.ini files remain accepted as a compatibility fallback, but new images use manifest.ini.

The registry scans /usr/lib/leonos/apps. Shells, the desktop start menu, file associations, icons, GUI launch, and API installation all consume the same records. API packages write their manifest after extraction, so a newly installed application becomes discoverable without rebuilding the system.

Applications and SDK clients can include <leonos/app.h> and use:

leonos_app_registry_refresh();
leonos_app_registry_resolve("notepad", path, sizeof(path));
leonos_app_registry_default_for_extension(".txt", path, sizeof(path));

The public SDK header is installed at devtools/include/leonos/app.h.