---
title: "Install & first run"
description: "Read the Sonomos Support Center guide for Install & first run. Download, install, answer three questions, and watch Locke catch something real."
url: "https://sonomos.ai/support/locke/install/"
source: "https://sonomos.ai/support/locke/install/"
---

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](https://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. |

Windows 10 before version 1809 is refused

The floor is **Windows 10 version 1809, build 17763** — every build above it, and all of Windows 11. Below that the installer names your build, says nothing has been installed and nothing on the computer has been changed, and quits. That is deliberate: a screening layer that is not running looks exactly like one that found nothing, so it refuses to install rather than appear to work.

What Windows shows about the publisher

The Windows installer is signed, and the publisher reads **Sonomos, Inc.** — not _Unknown publisher_. That signature is what SmartScreen reads. If Windows does put a warning in front of you, check the publisher line says Sonomos, Inc. before you continue; if it does not, don't run the file. The Linux builds carry no code signature at all — no Linux loader or package manager reads one — so verify those against the SHA-256 published with the release.

If your organization installs software for you

Teams admins can push Locke through the same tooling they use for everything else, with the org policy already applied. If Locke appeared on your machine without you installing it, skip to step 3 — the setup was done for you, and your protection rules come from your admin. See [For team members](https://sonomos.ai/support/locke/members/).

## 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. |

Declining leaves you with a working install

Say no and nothing is elevated and nothing changes. The engine, the detection, the reports and the browser extension all still work. What you lose is capture of desktop and command-line tools. You can run the script later; it is never a surprise prompt mid-session.

Log out and back in afterwards

Group membership only takes effect for new login sessions, so until you do, the proxy cannot join `sonomos-proxy` and capture will not start. Every one of the four operations above is recorded in `~/.sonomos/install-manifest`, including whether it already existed before the script ran — which is how [Uninstall Locke](https://sonomos.ai/support/locke/uninstall/) knows to remove only what Locke actually created.

## 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. |

Tip

Nothing here is permanent, and nothing is hidden forever. The answer only sets the starting point — every control is reachable from Settings whichever one you pick, and you can change your mind at any time.

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.

The first setup screen. Pick the row that sounds like you.

If Windows asks to install a certificate

On Windows the certificate authority is trusted on first run, not at install time, so the operating system's own “you are about to install a certificate” prompt can appear while the app is starting. The certificate is generated on your machine and its private key never leaves it. It exists so Locke can read what a **command-line tool or script** sends to an AI API before it is encrypted.

Declining does **not** turn off browser protection: the extension screens a request inside the page and needs no certificate at all. What you lose is screening of command-line and API traffic. Node tools are a special case — Node ignores the operating system's trust store, so Locke also sets `NODE_EXTRA_CA_CERTS` for new shells. Without it a captured Claude Code or gemini-cli fails with a TLS error that looks exactly like an untrusted certificate.

Security & technical documentation

What that certificate is and how it's generated — and every other security, compliance or technical question — is documented on the Sonomos Trust Centre: [trust.sonomos.ai](https://trust.sonomos.ai) (access-restricted during beta).

## 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.

_The Getting Started card at the top of the Dashboard: a progress bar reading 2 of 3 done, with steps for turning on protection, choosing what to protect, and seeing it protect something real._

Two of three done. The last step ticks itself off the first time Locke catches something in real use.

1. **Turn on protection.** Ticks off when the engine is running. If it isn't, there's a green Start protection button right there.
2. **Choose what to protect.** Ticks off once you've opened [Controls](https://sonomos.ai/support/locke/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.
3. **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.

Walkthrough

### From a fresh install to your first catch