The Locke Extension.
It holds your prompts to ChatGPT, Claude, Gemini and eight other AI services in the browser, so Locke can screen them on your device before they're sent. Free.
The extension is a separate install from the Locke desktop app, which does the scanning. Install both.
Three steps
- 1
Install the extension and the Locke desktop app
Install both. They find each other automatically.
- 2
Use AI sites as you always have
On ChatGPT, Claude, Gemini and eight other AI services, the extension holds your prompt in the page when you submit it.
- 3
Locke screens it on your device
The desktop app screens supported held requests locally and answers allow, redact or block. Coverage depends on request path and transport (limits below).
- Scanning runs on your device. The extension needs no account. The desktop app signs in.
- No remote screening or background analytics. Local operational records are kept.
- Runs on every website. Only requests the desktop app classifies as AI are screened. The rest pass unchanged.
- Protected requests fail closed by default. Disabled-site settings, explicit bypasses and unsupported paths limit coverage.
Where it screens, and where it can't
Locke knows these AI services by name and always screens their prompt requests.
Screened: eleven services
Some sites are limited to selected paths, and not every upload or transport is covered. A listed host does not mean every request is screened. Microsoft Copilot browser chat is not screened by the extension: it uses a WebSocket the extension cannot hold.
- OpenAI / ChatGPTchatgpt.com · chat.openai.com · platform.openai.com
- Anthropic / Claudeclaude.ai · claude.com · console.anthropic.com
- Google Gemini / AI Studiogemini.google.com · aistudio.google.com
- xAI / Grokgrok.com · console.x.ai
- Perplexityperplexity.ai
- DeepSeekchat.deepseek.com
- Mistral / Le Chatchat.mistral.ai
- Alibaba Qwenchat.qwen.ai
- Meta AImeta.ai
- DuckDuckGo Duck.aiduck.ai
- Kagi Assistantassistant.kagi.com
Not screened: search boxes on six hosts
The extension runs here, but a search box submits by navigating, and the navigation leaves before page code can see it. Nothing typed into these boxes is screened, and no switch suggests otherwise. Screening them needs a different design (a warning you confirm before the page leaves) and is deferred. Other requests from these pages are classified as usual.
www.google.com · www.bing.com · duckduckgo.com · kagi.com · you.com · search.brave.com
Two of them also carry chat: duckduckgo.com and kagi.com serve Duck.ai and Kagi Assistant, which are screened normally. Their search boxes are not.
What it can read, and where it has gaps
The page hooks can read request headers and copy body data while deciding whether a request is in scope. Only qualifying held requests go to the desktop app for screening. Some supported AI pages upload attachments straight to object storage on another host. Those uploads can be held too.
Coverage has gaps for prompts in navigations or query strings, WebSockets, traffic from workers and unsupported upload forms. Read the current coverage notes before relying on it for a particular site or task.
The desktop app's HTTPS discovery and router are a separate path, with broader potential reach. The extension's fixed host permissions don't describe it. See the Locke Privacy Policy for local processing, retention and controls.
Common questions
Do I need the Locke desktop app too?
Yes. The extension holds requests. The desktop app scans and redacts them locally. If it isn't running, protected requests are blocked.
What data does the extension process?
Request bodies, including supported file uploads, and metadata such as the method, destination, path/query and page-set headers. Requests with a body, on any website, go through native messaging to the desktop app on the same computer, not to Sonomos servers. The app screens the ones it classifies locally as AI and releases the rest unchanged. Stored locally: disabled-site choices, session status/counters, and a rolling 100-entry operational audit log that can include diagnostic URLs and source paths. Local connection checks carry browser/version information, and Chromium registration adds the extension ID. The desktop app separately uses account, licensing, settings and optional support services, described in the Locke Privacy Policy.
Which AI sites does it screen?
Any AI site it recognises. The extension runs on every site and the desktop app classifies requests locally, so unlisted AI services are screened too. Eleven listed services are always screened on their prompt paths: ChatGPT, Claude, Gemini and AI Studio, Grok, Perplexity, DeepSeek, Le Chat, Qwen, Meta AI, Duck.ai, Kagi Assistant, and the OpenAI, Anthropic and xAI developer consoles. Microsoft Copilot (copilot.microsoft.com) is not: its chat runs over a WebSocket the extension cannot hold. We plan to add this in a future release.
Does it screen what I type into a search box?
No. A search box submits by navigating, and a navigation leaves before any page code runs. The same goes for the address bar, a browser's default search engine and a ?q= link. The extension screens request bodies sent by the page's own script. Screening navigation-borne prompts needs a different design and is deferred.
Where do I get it?
From the Chrome Web Store (which also serves Brave and Vivaldi), Microsoft Edge Add-ons or Firefox Add-ons. The buttons here and in the desktop app open those listings. Check a listing against the extension IDs at the bottom of this page. It is a separate install from the desktop app, which does the scanning: without the app running, protected requests are blocked rather than screened.
Only these listings are ours
Check that the ID in the store URL matches before you install.
- Chrome
- jkpchenllbgfknebokdncegdddknnbpp
- Edge
- lfmmhkkghindbnphkkfbhiinnanmmgjo
- Firefox
- locke-extension
Covered by the Locke Privacy Policy and the EULA. How Locke keeps this secure
