Global USE flags

Flag	Description	Packages
X		5
cuda	Enable accelerated video encoding on NVIDIA hardware	3
debug		5
doc		4
examples		4
ffmpeg		2
gnome		2
inotify	Use the Linux kernel inotify subsystem to notice changes to mpd music library	2
introspection		2
jack		2
nls		2
openal		2
opencl	Allow OpenCL Graphics Acceleration. This may require extra graphics card drivers.	2
opengl		2
pipewire	PipeWire support	4
pulseaudio	Enable support for audio sink/source through pulseaudio modules	3
python	Use <pkg>dev-lang/python</pkg> to process source and documentation source files	2
sndfile		2
systemd	Enable support for systemd socket activation	4
tbb	Use threading building blocks library from <pkg>dev-cpp/tbb</pkg>.	2
test		6
vaapi		2
vulkan		2
wayland		5
x264	Enable software H.264 encoding via <pkg>media-libs/x264</pkg>	2
zeroconf		2
zlib		2

Local USE flags

app-emulation

proton-ge-custom-meta

Flag	Description
kde

wine-mono

Flag	Description
shared	Install pre-unpacked files which do not need to be copied into the Wine prefix

app-misc

hermes-agent

Flag	Description
anthropic	Native Anthropic provider SDK (lazy-installable upstream)
edge-tts	Edge TTS voice backend (lazy-installable upstream)
mcp	MCP client/tool support via dev-python/mcp 2.x
telegram	Telegram messaging platform adapter (lazy-installable upstream)

dev-libs

json-c

Flag	Description
cpu_flags_x86_rdrand
static-libs
threads

dev-python

headroom-ai

Flag	Description
proxy	Install runtime deps for the Headroom proxy server and MCP server (headroom proxy). Upstream also wants sqlite-vec for the memory vector index; it is not packaged here and that feature degrades gracefully at runtime.
reports	Install deps for report generation
spreadsheet	Install deps for .xlsx/.xls ingestion

dev-util

nvidia-cuda-toolkit

Flag	Description
clang
debugger
nsight
profiler
rdma
sanitizer

games-action

polymc

Flag	Description
lto	Enable link-time optimization
qt6	Build with Qt6 support instead of the default Qt5

games-util

gamemode

Flag	Description
elogind

gnome-base

gconf

Flag	Description
ldap	Build backend which enables default mail accounts, addressbooks and calendars for Evolution to be configured using each user's LDAP entry."
policykit

media-gfx

blender

Flag	Description
${PYTHON_REQUIRED_USE}
alembic	Add support for Alembic through <pkg>media-gfx/alembic</pkg>.
bullet	Enable Bullet (Physics Engine).
collada	Add support for Collada interchange format through <pkg>media-libs/opencollada</pkg>.
color-management	Enable color management via <pkg>media-libs/opencolorio</pkg>.
cycles	Build cycles renderer (requires <pkg>media-libs/openimageio</pkg> and <pkg>dev-libs/boost</pkg>).
cycles-bin-kernels
dds	Adds DDS textures support to Blender.
embree	Use embree to accelerate certain areas of the Cycles render engine.
experimental
fftw
fluid	Adds fluid simulation support via the built-in Mantaflow library.
gmp
headless	Build without graphical support (renderfarm, server mode only).
hip
hiprt
jemalloc
jpeg2k
man
manifold
nanovdb	Enable nanoVDB support in Cycles. Uses less memory than regular openVDB when rendering.
ndof	Enable NDOF input devices (SpaceNavigator and friends).
oidn	Enable OpenImageDenoiser Support
openexr
openimageio	Enable OpenImageIO Support
openpgl
opensubdiv	Add rendering support form OpenSubdiv from Dreamworks Animation through <pkg>media-libs/opensubdiv</pkg>.
openvdb	Enable openvdb for volumetric processing, like the voxel remesher. Also enables volumetric GPU preview rendering for Nvidia cards.
optix	Add support for NVIDIA's OptiX Raytracing Engine.
osl	Add support for OpenShadingLanguage scripting.
pdf
potrace	Add support for converting bitmaps into Grease pencil line using the potrace library.
pugixml	Enable PugiXML support (Used for OpenImageIO, Grease Pencil SVG export)
renderdoc
rubberband
sdl
tiff
truetype
valgrind	Add support for memory debugging using <pkg>dev-util/valgrind</pkg>
webp

media-libs

opensubdiv

Flag	Description
glfw	Build all example files that uses (<pkg>media-libs/glfw</pkg>)
openmp
ptex	Adds support for faster per-face texture mapping through <pkg>media-libs/ptex</pkg>
tutorials	Install the tutorials

openvr

Flag	Description
static

openxr

Flag	Description
layers

wivrn

Flag	Description
gui
nvenc
wireshark-plugins	Build the <pkg>net-analyzer/wireshark</pkg> plugin for the WiVRn protocol

media-sound

mpd

Flag	Description
${DECODER_PLUGINS}
${ENCODER_PLUGINS}
${OUTPUT_PLUGINS}
alsa
ao
audiofile
bzip2
cdio	Use libcdio for ISO9660 parsing support
chromaprint	Enable ChromaPrint / AcoustID support
cue	Enable CUE sheet support
curl	Support for web stream listening
dbus
eventfd	Use the eventfd function in MPD's event loop
expat
faad	Use external faad library for AAC decoding
fifo	Support writing audio to a FIFO
flac
fluidsynth	Enables Fluidsynth MIDI software synthesis (discouraged)
gme	Enables support for <pkg>media-libs/game-music-emu</pkg> for playing various video game music formats.
icu
id3tag	Support for ID3 tags
lame	Support for MP3 streaming via Icecast2
libmpdclient	Enable support for remote mpd databases
libsamplerate
libsoxr	Enable the libsoxr resampler
mad
mikmod
mms
modplug
mpg123	Enable support for mp3 decoding over <pkg>media-sound/mpg123</pkg>
musepack
network	Enables network streaming support
nfs	Enable support for the Network File System
openmpt	OpenMPT decoder plugin
opus
oss
pipe	Support writing audio to a pipe
qobuz	Build plugin to access qobuz
recorder	Enables output plugin for recording radio streams
samba
selinux
sid	Build with SID (Commodore 64 Audio) support
signalfd	Use the signalfd function in MPD's event loop
snapcast	Snapcast audio plugin
sndio	Enable support for the <pkg>media-sound/sndio</pkg> backend
soundcloud	Build plugin to access soundcloud
sqlite
twolame	Support twolame MPEG-2 encoding
udisks
upnp
vorbis
wavpack
webdav	Enable using music from a WebDAV share
wildmidi	Enable MIDI support via wildmidi
zip

net-libs

ixwebsocket

Flag	Description
ssl
ws	Build the ws utility

net-misc

remmina

Flag	Description
appindicator
crypt
cups
gvnc	Enable GVNC plugin using gtk-vnc, suitable for KVM and Vino servers
keyring
kwallet	Enable KDE Wallet plugin
rdp
spice	Support connecting to SPICE-enabled virtual machines
ssh	Enable support for SSH/SFTP protocol
vnc
webkit

sunshine

Flag	Description
libdrm	Enable KMS video capture via <pkg>x11-libs/libdrm</pkg>
svt-av1	Enable software AV1 encoding via <pkg>media-libs/svt-av1</pkg>
trayicon	Enable system tray icon
x265	Enable software HEVC encoding via <pkg>media-libs/x265</pkg>

trackma

Flag	Description
cli
gtk
ncurses
qt5

sci-mathematics

cgal

Flag	Description
demos

sys-kernel

linux-firmware

Flag	Description
bindist
compress-xz	Compress firmware using xz (<pkg>app-arch/xz-utils</pkg>) before installation
compress-zstd	Compress firmware using zstd (<pkg>app-arch/zstd</pkg>) before installation
deduplicate	Create symlinks for all firmware that is duplicate using rdfind
dist-kernel
initramfs	Create and install initramfs for early microcode loading in /boot (only AMD for now)
redistributable	Install also non-free (but redistributable) firmware files
savedconfig	Allows individual selection of firmware files
unknown-license	Install firmware files whose license is unknown

---