Control your Razer device's RGB, effects, and settings — from the terminal or the browser. No extra software, no drivers, no background process.
I got really tired of the Razer app and other things always running in the background, so I wrote this small Python app. It talks to the device directly over USB-HID, sets the color, and exits.
No install at all? There's also a browser version — same protocol over WebHID. Just open it in Chrome/Edge and click Connect. See Browser app.
- Nothing runs in the background — it sets the lighting and quits.
- Zero dependencies — pure Python standard library.
- Windows & Linux — picks the right HID backend automatically.
- Saves to the mouse's onboard memory, so the color sticks with no software running — including on the Viper Mini, where Razer hides this feature.
Needs uv — it brings its own Python, so there's nothing else to install.
Windows
powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"
uv syncLinux / macOS
curl -LsSf https://astral.sh/uv/install.sh | sh
uv syncuv sync sets up the venv and Python 3.14 (still zero dependencies).
uv run python src/main.py # list devices, or open the menu in a terminal
uv run python src/main.py red # solid color (name, ff0000, or '255,0,0')
uv run python src/main.py spectrum # on-device effect
uv run python src/main.py breathing 00ff88
uv run python src/main.py reactive ff0000 # light up on keypress/click (multi-zone)
uv run python src/main.py starlight 00ff88 # twinkling stars (multi-zone)
uv run python src/main.py off # solid black
uv run python src/main.py red -d all # every connected Razer device
uv run python src/main.py -m # interactive menu-d picks a device by list number (-d 2), product id (-d 008a), or all. The color saves to onboard memory by default; add --temp to apply it just once.
Other device-internal settings (stored on the device, no software needed afterward):
uv run python src/main.py --brightness 60 # brightness 0-100
uv run python src/main.py --dpi 1600 # mouse DPI (or --dpi 1600,800 for x,y)
uv run python src/main.py --poll 1000 # polling: 8000/4000/2000/1000/500/250/125 Hz (HyperPolling)
uv run python src/main.py --info # read battery, firmware, serial, DPI, HzThe browser app additionally has a per-key keyboard editor and a per-zone mouse editor (logo, scroll wheel, side strips, underglow), plus scroll-wheel modes, game/macro toggles, and named profiles (saved in the browser).
Save the lighting of all your devices under a name, then bring it back with one command — and have a profile apply automatically when a game starts (reverting to default when it exits):
uv run python src/main.py red # set things up how you like them...
uv run python src/main.py --profile save default # ...and snapshot that as the fallback
uv run python src/main.py 00ff88 && uv run python src/main.py --profile save fps
uv run python src/main.py --profile load fps # apply a profile (list / delete too)
uv run python src/main.py --game add cs2.exe fps # while CS2 is in the foreground -> [fps]
uv run python src/main.py --watch # watch & auto-switch (ctrl-c to stop)Profiles live in docs/profiles.txt and the game map in docs/games.txt — both plain, editable text. If any game mappings exist, the startup launcher keeps watching after logon, so game detection works with zero extra setup (--startup install). Detection is the foreground app on Windows (UWP/Store games included) and a process scan on Linux (Wine/Proton titles are matched best-effort by their .exe name).
Some wireless Razer headsets keep their equalizer in the headset's own DSP, set over a vendor HID interface — so RazerKit can set it with no Synapse and no audio driver:
uv run python src/main.py -d 0555 --eq game # flat | game | music | movie
uv run python src/main.py -d 0555 --eq 0,0,-2,0,3,3,2,1,0,0 # 10 custom band gainsVerified protocol for the BlackShark V2 Pro (1532:0555) only; other headsets either use a host-side DSP in Synapse (nothing on-device to set) or an uncaptured protocol — --force lets you try anyway. Wired Kraken-family EQ ("THX Spatial") is host software, not the headset, so no tool can set it device-side.
Blade laptops expose performance mode and the battery charge limit over the same USB-HID protocol (the keyboard MCU bridges to the embedded controller), so RazerKit drives them too — no Synapse. Performance mode also sets the firmware fan curve; there's deliberately no manual fan-rpm knob (a bad fixed speed is a thermal risk).
uv run python src/main.py --perf gaming # balanced | gaming | creator (also sets the fan curve)
uv run python src/main.py --charge 80 # cap charging at 50-95% (--charge off = no limit)
uv run python src/main.py --info # also shows perf mode / fan rpm / charge limit on a BladeGPU MUX / Optimus switching is not possible from any userland tool — on 2023+ Blades (Advanced Optimus) the switch lives in NVIDIA Control Panel → Manage Display Mode (NVIDIA has declined to expose an API; Razer removed it from Synapse on these models on purpose), and on older Blades it's a firmware setting + reboot. What RazerKit can do is power the dGPU off/on at the device level ("Eco", the same approach ASUS G-Helper uses) — saves battery when you're on iGPU-only work:
uv run python src/main.py --gpu status # list iGPU/dGPU and their state (+ MUX guidance)
uv run python src/main.py --gpu eco # power the NVIDIA dGPU off (admin, Windows)
uv run python src/main.py --gpu on # bring it backDon't want to install anything — not even Python? Open the web version in Chrome or Edge, click Connect, pick your device, and set colors/effects. It speaks the exact same Razer HID protocol from the browser via WebHID.
- Same 281-model table, same color/effect builders as the CLI.
- Runs entirely client-side — nothing is uploaded, no background process.
- Or run it locally:
python -m http.serverin the repo, then openhttp://localhost:8000/frontend/.
Chrome blocks WebHID on protected (mouse/keyboard) HID collections, so a few devices whose control interface is a plain mouse collection may be refused by the browser — the app tells you when that happens. The CLI has no such restriction.
Windows — works out of the box. If other RGB software is running, close it first — it can re-apply its own profile and overwrite your color.
Linux — you need write access to /dev/hidraw*. Either run with sudo, or add a udev rule once:
echo 'SUBSYSTEM=="hidraw", ATTRS{idVendor}=="1532", MODE="0660", TAG+="uaccess"' \
| sudo tee /etc/udev/rules.d/99-razer.rules
sudo udevadm control --reload && sudo udevadm triggerRe-apply your saved colors at every logon (replays settings.txt):
Windows — no admin needed. Drops a hidden RazerRGB.vbs in your Startup folder; it appears in Task Manager → Startup apps as RazerRGB, where you can toggle it too.
uv run python src/main.py --startup install
uv run python src/main.py --startup remove # undoLinux — no admin needed (adds a ~/.config/autostart entry):
uv run python src/main.py --startup install
uv run python src/main.py --startup remove # undoA built-in MCP server lets Claude (or any MCP client) change your lighting — still dep-free, pure stdlib over stdio.
uv run python src/mcp_server.pyTools: list_devices, set_color, set_effect, get_polling_rate. For Claude Code, the included .mcp.json registers it automatically — open the project and approve the razerkit server when prompted (or run /mcp). Then just ask: "set my mouse to ff1e00".
Verified on the Razer Viper Mini; ~260 other models are included. Some may need a tweak — --txn / --led are there for tuning. Effects like wave need a multi-zone device; single-LED mice (Viper Mini) say so instead of doing nothing.
If this saved you from running Synapse in the background, consider sponsoring on GitHub — it keeps projects like this maintained.