Start here
Install & first run
Download, install, answer three questions, and you're protected. The whole thing takes about two minutes, and the only decision that matters is the first one.
1. Download and install
Get the installer for your operating system from sonomos.ai/downloads. Locke runs on x64 Windows and Linux. macOS is coming soon.
| Platform | File | How to install |
|---|---|---|
| Windows x64 | Locke-<version>-win-x64.exe | Double-click it. There is no wizard — no directory chooser, no component page, and no administrator prompt. It installs into your own user profile and opens when it finishes. |
| Linux x64 (Debian, Ubuntu) | Locke-<version>-linux-x64.deb | Install it with your package manager: sudo apt install ./Locke-<version>-linux-x64.deb. There is no automatic updater on Linux — download and install a newer package to update. |
| Linux x64 (Fedora, RHEL, openSUSE) | Locke-<version>-linux-x64.rpm | Install it with your package manager: sudo dnf install ./Locke-<version>-linux-x64.rpm (or zypper). There is no automatic updater on Linux — download and install a newer package to update. |
2. Linux: one privileged step, run by you
On Linux, installing Locke needs no privilege at all — the app unpacks and verifies its own engine into your home directory (~/.local/share/sonomos/app) the first time it runs, as you, with no password. Screening your browser needs nothing more than that plus the extension.
Screening your desktop and command-line traffic is the part that needs root, and it is a separate command with its own name so that elevating is something you choose after reading what it does:
~/.local/share/sonomos/app/locke/setup-capture.sh
It prints every command in full, then asks once. Four privileged operations, one password prompt:
| It does this | Because |
|---|---|
Creates the system groups sonomos-proxy and sonomos-bypass, and adds you to them | The traffic redirect has to exclude the proxy's own outbound traffic, and it does that by group id. Without it the proxy's egress is redirected back into itself. |
Installs a root-owned helper at /usr/local/libexec/sonomos-redirect | A tiny script that does nothing but add and remove one firewall table. Root-owned so you cannot edit it — which is what makes the next line safe. |
Installs /etc/sudoers.d/sonomos-redirect | Lets you run exactly that helper's redirect-on and redirect-off, and nothing else, without a password. Not a convenience: the redirect is disarmed automatically at shutdown, where there is no terminal to type a password into, and a redirect left armed over a stopped Locke breaks all HTTPS on the machine. |
| Adds this device's certificate authority to the system trust store | The proxy has to terminate TLS to see what a command-line tool is sending. The certificate is generated on this machine and its private key never leaves it. |
3. The setup questions
The first time you open Locke it asks how much of the machinery you want to see. This is the only question in setup you should think about for more than a second.
| If you pick | You're saying | The app then |
|---|---|---|
| Keep it simple | Just protect me — pick smart defaults and stay out of my way. | Hides the advanced controls, chooses everything for you, and explains things without jargon. |
| I set this up for others | I look after privacy or compliance for a team and need to show it's working. | Leads with the compliance and reporting surfaces, and keeps the settings overridable. |
| I want full control | I'm technical — give me the settings, rules, and raw config. | Shows everything, including the custom-rule editor and the Sandbox, up front. |
After that, setup does the rest itself. The detection engine and its models came inside the installer — there is nothing to download and no size or tier to pick. On Windows it runs where the installer put it; on Linux the app unpacks and checksum-verifies it into your home directory. There is no key to create, and setup does not ask you for one: a detected value is replaced by a one-way token derived from the value itself, so there is nothing to generate, store or lose.
The last thing setup does is ask the engine to scan one line of sample text, and show you what it caught. That is worth reading precisely: it proves the detection engine is installed, running on this machine, and detecting. It is a direct scan, so it does not exercise capture — nothing was intercepted from a browser or a command line to produce it, and a green result here is not proof that either capture path is working. That proof is section 5, and it takes a real request from a real app.
What you'll see
The Locke setup wizard on its first step, offering three choices: Keep it simple, I set this up for others, and I want full control.
4. The Getting Started card
When setup finishes you land on the Dashboard with a checklist at the top. It tracks real progress, not clicks — each item ticks off when the thing has genuinely happened.
Welcome to Locke
Two of three done. The last step ticks itself off the first time Locke catches something in real use.
- Turn on protection. Ticks off when the engine is running. If it isn't, there's a green Start protection button right there.
- Choose what to protect. Ticks off once you've opened Controls and seen the list of AI apps and sites Locke is watching. The defaults are sensible — this step is about knowing what they are.
- See it protect something real. Ticks off when Locke masks something in actual use — not the sample from setup. This is the step worth waiting for.
Dismiss the card with Got it whenever you like. You can bring it back from Support › Replay the welcome guide.
5. Prove it works
Open ChatGPT, Claude, or any other protected app, and send a message with something recognizably yours in it — your own email address is the easy test. Then come back to the Dashboard. The item appears in the live feed marked masked, and the third checklist step ticks off.
From a fresh install to your first catch
1Setup has finished and you're on the Dashboard. The status card is grey — protection isn't running yet — and the checklist is waiting.
Read all 5 steps as text
- Setup has finished and you're on the Dashboard. The status card is grey — protection isn't running yet — and the checklist is waiting.
- Click Start protection on the status card.
- The card turns green and reads Protected. Step one of the checklist ticks off. Locke is now watching every protected app and site.
- Now go and use an AI tool normally — send ChatGPT a message with your email address in it. Locke masks it on the way out.
- Back on the Dashboard, the catch is in the live feed, the counters have moved, and the last checklist step is done. Nothing else to set up.
What using it looks like from here
Nothing. That's the intended answer. Locke starts with your computer, sits in the corner of the screen as a small status dot, and masks as it goes. The app is there when you want to check on it, change what's protected, or pull a report — not something you need to visit.
The rest of this guide is a tour of what's inside for when you do. Start with The window. When you want it gone, Uninstall Locke says exactly what removal reverses on each platform, and what it cannot reverse for you.
A day in: protection on, items caught, nothing to do.
