Privacy Policy
Your prompts and notes stay yours.
Effective date: 30 April 2026 · Last updated: 30 April 2026
The short version: Four Line does not collect, transmit, or share any personal data, browsing activity, prompts, notes, or AI conversations. Everything happens locally inside your browser. We have no servers that receive anything from the extension.
1. Who we are
Four Line is a Chrome browser extension developed and operated by Four Line ("we", "us", "our"). Our primary website is fourline.ai. This Privacy Policy describes how the Four Line extension handles information.
2. What this policy covers
This policy applies only to the Four Line browser extension distributed via the Chrome Web Store and the assets it loads (icons, scripts bundled inside the extension package). It does not cover the public website at fourline.ai, which has its own privacy notice, nor any third-party AI service you choose to open inside the workspace — each AI provider has its own privacy policy that governs your direct interaction with them.
3. What we do not collect
We have intentionally designed Four Line so that the following information never leaves your computer and is never seen by us:
The text of any prompt you type into the broadcast bar or into an AI service's chat box.
The text of any AI response shown inside Four Line.
Any prompt or note you save to your local Library.
Any image you paste or upload into a note.
The list of AI services you have configured, the groups you have arranged them into, or the URL of the page each one is on.
Browsing history, URL list, tab list, or referrers from sites outside the workspace.
Account credentials, cookies, session tokens, or autofill data from any AI service.
IP address, device identifiers, advertising identifiers, telemetry, or usage analytics.
Crash reports or error reports.
The extension contains no analytics SDKs, no tracking pixels, no fingerprinting code, and no remote code execution paths. The JavaScript that runs in your browser is exactly the JavaScript shipped in the .crx package — auditable in the Chrome Web Store source listing.
4. What is stored locally on your device
Four Line uses the standard Chrome localStorage and chrome.storage.local APIs to remember your workspace between sessions. This data is written to your local browser profile and is never transmitted off-device. We cannot read it. The stored items are:
Workspace state — the AI services you have added, their group assignments, which group is active, which tab is focused, your theme preference, and your sidebar position.
Prompt library — prompts you save (title and body) for reuse across AI services.
Notes library — notes you write (title, rich-text body, project assignment, timestamps). Images you paste or upload are embedded as base64 data URLs inside the note's body and never leave your device.
Per-tab URL — the current URL of each AI service pane so the extension can reopen it on the same page next time (for example, keeping a Gemini account on /u/2).
Pending captures — when you right-click a selection on any webpage and choose "Save to Four Line as Prompt" or "Save to Four Line as Note", the highlighted text and the title you provide are queued in chrome.storage.local until the Four Line tab is open and can move the item into your library. The queue is then cleared.
You can clear all of this at any time by removing the extension from chrome://extensions, or by using the Reset button in Four Line Settings. There is no cloud copy.
5. Permissions and why we ask for them
Four Line requests the minimum set of Chrome permissions needed for its workspace to function. Each one is used solely on your local device and only for the feature listed below:
declarativeNetRequest and declarativeNetRequestWithHostAccess — strip the X-Frame-Options and CSP frame-ancestors response headers on the AI service domains so they will render inside the extension's split-view iframes. Without this, the side-by-side workspace would be impossible. We do not read, log, or modify your network traffic in any other way.
webNavigation — detects when you navigate inside an embedded AI service (for example, opening a saved Claude conversation, or switching a Gemini account to /u/2). Used only to remember the URL of each pane locally so the workspace restores it on next launch.
contextMenus — adds the "Save to Four Line as Prompt" and "Save to Four Line as Note" right-click items. They only do anything when you click them.
storage — persists your workspace, prompt library, notes library, and the small pending-captures queue. Without this you would lose your setup every time the browser closed.
activeTab and scripting — used so that when you right-click a text selection and choose to save it, Four Line can ask you for a title via a small window.prompt() dialog inside the tab where you right-clicked. activeTab grants temporary access only on that one tab, only at the moment you invoked the menu. We use scripting only to call window.prompt(). No remote code is loaded or executed.
Host permissions for AI service domains — required for the four reasons above to apply on the right pages. Each domain is listed explicitly: chatgpt.com, openai.com, claude.ai, anthropic.com, gemini.google.com, aistudio.google.com, accounts.google.com, grok.com, kimi.ai, kimi.com, moonshot.cn. We do not request <all_urls> or any wildcard above these.
6. Content scripts we inject into AI service pages
Four Line injects four small scripts into the AI service pages it embeds. They run only on those domains, never on other websites, and never transmit anything off your device.
anti-framebusting — stops AI sites from detecting that they are inside an iframe and refusing to render. Reads no user data.
url-tracker — detects in-page URL changes (single-page-app navigation) so Four Line can remember which Claude / Gemini / etc. page you were on. The URL is sent to the extension's own background process and saved locally. Nothing is transmitted off the device.
broadcast-receiver — listens for a "broadcast prompt" message from the Four Line workspace and types that prompt into the AI service's input field. Active only when you press the broadcast Send button. The text it injects is the text you typed into the broadcast bar — Four Line does not read or extract anything from the AI page itself.
selection-saver — provides a small floating "Save as Prompt / Save as Note" toolbar when you select text inside an AI pane. The selected text is captured only when you click one of those buttons, and only with a title you confirm.
7. Network requests
The Four Line extension itself does not make any outbound network requests. It does not contact our servers, third-party servers, or any remote endpoint while running. The only network activity that occurs is initiated by you, when you load an AI service inside one of the panes — that traffic flows directly between your browser and the AI provider, exactly as it would if you opened the site in a normal tab.
8. Third-party AI services
Four Line is a workspace that embeds third-party AI services. When you log in to any of them through Four Line, you are interacting directly with that service over a normal HTTPS connection using your own account. Their privacy policies and terms apply to that interaction. Four Line has no visibility into the content of those conversations and we have no business relationship with these providers. Links to the privacy policies of the default services Four Line ships with:
ChatGPT (OpenAI): openai.com/policies/privacy-policy
Claude (Anthropic): anthropic.com/legal/privacy
Gemini and AI Studio (Google): policies.google.com/privacy
Grok (xAI): x.ai/legal/privacy-policy
Kimi (Moonshot AI): kimi.com/privacy
9. Children
Four Line is a general-purpose productivity tool not directed at children under the age of 13. We do not knowingly collect personal information from children — and given that we do not collect personal information at all, this is also literally true. The AI services Four Line embeds may have their own age policies; please check theirs.
10. Changes to this policy
If we materially change how the extension handles data, we will publish an updated version of this page with a new "Last updated" date and bump the extension's version number. If a future version of Four Line ever introduces a feature that requires sending data off-device (for example, an opt-in cross-device sync), that feature will be opt-in, clearly labelled in the user interface, and described in this policy before the version is published.
11. Your rights and controls
Because Four Line does not transmit or retain any data about you, there is no remote dataset to access, correct, port, or delete. You can fully exercise control by:
Using the Export button in Settings to download a JSON file of your tabs, groups, prompts, and notes.
Using the Reset button in Settings to erase everything Four Line has stored locally.
Removing the extension from chrome://extensions — this also clears its local storage.
Deleting individual prompts, notes, or projects from inside the Library.
If you are in the European Union, the United Kingdom, California, or another jurisdiction with statutory data-subject rights, those rights apply only to data we hold about you — and we hold none. We will respond to verifiable requests under any applicable law.
12. How to reach us
Questions, feedback, or security reports: write to hello@fourline.ai or open an issue at our repository linked from fourline.ai. For Chrome Web Store policy concerns, you can also use the "Report abuse" link on the extension's listing.