Your Local PC Copilot

A local-first assistant that runs entirely on your machine, shows its plan before it moves, and acts only once you approve.

Launch the app→ Download for Windows
No account No cloud No telemetry
Nyx
Local
Ask Nyx to do something…↑
Built different

Powerful on your PC. Private by default.

The model, the reasoning and your files never leave the machine. Nyx works offline and keeps every action under your control.

01

Runs fully on-device

Your model runs locally through the QVAC SDK — pick the size that fits your PC. No servers, no API keys, nothing leaves your machine.

02

Plans before it acts

Every task is shown as a clear plan first. Nothing runs until you approve it — you stay in control at all times.

03

Guarded & signed

NetGuard blocks unknown hosts and the validator refuses destructive commands. Every action leaves a signed receipt.

How it works

From request to signed result.

01

Ask

Describe what you want in plain language — no commands to memorize.

02

Review the plan

Nyx breaks it into concrete steps and shows exactly what it will touch.

03

Approve

You confirm. The validator and NetGuard keep risky actions out.

04

Get a receipt

Every run is signed and saved to ./evidence so you can verify it later.

The numbers

Local by design, not by promise.

0%
of inference runs on your device
0
bytes of your data sent to the cloud
0%
of actions require your approval

Open source under Apache-2.0. Read the code, run the verifier, check the signed receipts yourself.

Choose your brain

One app. A model for every PC.

Nyx isn't locked to a single model. Weak laptop or a beast rig — pick the size that runs smoothly on your hardware. On first launch Nyx checks your specs and pre-selects the best fit; you can switch anytime.

Lite
1B params

For older laptops and office PCs with no graphics card.

  • Runs onCPU only
  • Memory3 GB+ RAM
  • FeelInstant, snappy
  • Best forQuick tasks, files, everyday commands
Most people pick this
Balanced
4B params

The sweet spot for most modern laptops and desktops.

  • Runs onCPU or entry GPU
  • Memory8 GB+ RAM
  • FeelFast & noticeably smarter
  • Best forDaily driving, writing, light coding
Pro
8B params

For gaming PCs and workstations with a real GPU.

  • Runs on8–12 GB VRAM GPU
  • Memory16 GB+ RAM
  • FeelDeeper reasoning
  • Best forCoding, multi-step tasks, long context
Standard
3B params

A light step up from Lite for everyday work on typical laptops.

  • Runs onCPU or a basic laptop GPU
  • Memory6 GB+ RAM
  • FeelBalanced speed and quality
  • Best forEveryday assistant tasks
⚡

Built to stay smooth. Nyx runs models through QVAC's on-device runtime with memory-saving quantization (TurboQuant), so even the Lite tier stays responsive on modest hardware and bigger models don't eat all your VRAM. If your PC ever struggles, drop a tier and Nyx keeps up.

Get Nyx

Up and running in about a minute.

One download for Windows. No account, no setup maze — install it, pick a model that fits your PC, and start asking.

Nyx for Windows

Windows 10 / 11 · 64-bit · ~888 MB installer
Download for Windows→

macOS and Linux builds are on the way. Today Nyx is tuned and tested for Windows.

  • CostFree & open source
  • AccountNone needed
  • InternetOnly to download — runs offline after
  • Disk~888 MB app + 0.81–5.03 GB per model
01

Download & install

Grab the installer, run it, click through. No admin gymnastics, no bundled junk — about a minute start to finish.

02

Pick your model

On first launch Nyx reads your hardware and recommends a model that will run smoothly. See which one fits your PC →

03

It downloads once

Your model is fetched a single time (0.81–5.03 GB by tier) and stored locally. After that Nyx works with no internet at all.

04

Just ask

Type what you want in plain words. Nyx shows a plan, you approve, it acts — and every run is signed to ./evidence.

Good questions

Everything you're probably wondering.

Is my data actually private?+
Completely. Everything runs on your machine — your files, your prompts, and the model itself never leave your PC. No account, no cloud, no telemetry. Pull out the network cable and Nyx still works.
Will it slow down or lag my computer?+
Nyx is built to stay light. It runs a model sized for your hardware and only loads it while you're actually using it. On a modest PC, choose the Lite tier and it stays responsive — if things ever feel heavy, drop a tier and it speeds right back up.
What if my PC is weak or a few years old?+
You're covered. Nyx runs on CPU-only machines with 8 GB of RAM using the Lite model. On first launch it checks your specs and recommends the model that will actually run well — no guessing, no trial and error.
Can I choose which model to use?+
Yes — Nyx isn't tied to one model. Start with the recommended pick and switch to a bigger or smaller one whenever you like, right inside the app. Compare the tiers →
Is it safe to let an AI touch my PC?+
Nyx never acts on its own. It shows you a plain-English plan first, and nothing runs until you approve it. A validator blocks destructive commands, NetGuard blocks unknown network access, and every action is signed to ./evidence so you can check exactly what happened.
Do I need to be technical to use it?+
Not at all. You talk to it in normal language — “clean up my downloads”, “why is my PC slow”, “rename these files by date”. There are no commands to memorize.
Is it really free?+
Yes, and it's open source under Apache-2.0. No trial, no subscription, no upsell. You can read the code, run the verifier, and check the signed receipts yourself.
How much space does it need?+
The app itself is about (~888 MB). Each model you pick is downloaded once and stored locally — 0.81 GB for the Lite tier up to 5.03 GB for the Pro tier. You only ever download the models you choose.