LocalGist

Turns a lease, a plan-renewal notice, or a terms update into a plain-language brief — computed on your device, never uploaded anywhere.

Date: 2026-08-24 Form factor: Browser extension (Manifest V3) Browser surface: toolbar popup, context menu, on-demand content script (chrome.scripting), chrome.storage Status: Prototype

What it is

LocalGist reads whatever page you're stuck on — an insurance plan-renewal notice, a lease addendum, a terms-of-service update, an HR benefits portal — and turns it into a short brief: a TL;DR, the concrete facts (dates, dollar amounts, requirements), and a "worth a second look" list for the clauses people tend to skim past. It runs the summary through Chrome's built-in on-device model (Gemini Nano, via the LanguageModel API that shipped out of origin trial in Chrome 138), so the page text never leaves the browser.

Why it has to be an extension

The document you need briefed almost never lives on a site you control — it's your insurer's member portal, your landlord's tenant system, your bank's terms page. A website can call the on-device model on its own content, but it can't reach into a tab open on someone else's domain and read what's there. LocalGist's popup asks chrome.scripting to inject content.js into whichever tab is active when you click "Brief this page," which extracts the readable text and hands it to the on-device model running in the popup's own context. That combination — cross-origin page access plus the on-device model — only exists inside the browser process.

Who it serves

Anyone who's clicked "I agree" without reading, then wondered later what they agreed to. The direct version: someone renewing a health plan, signing a lease, or hitting a "we've updated our terms" banner, who wants the three facts that changed without reading four pages of policy language to find them.

Why it could be profitable

The free tier costs nothing to run per brief — the inference happens on the user's own hardware, not on a server LocalGist pays for, which is a real structural advantage over the cloud-AI summarizer extensions competing for the same shelf space. The paid tier ($4/month or $30/year) is what needs a backend LocalGist doesn't have yet: a saved brief vault across all documents you've read, a "re-check and diff" against a URL you briefed before, and a cloud fallback for the minority of devices where Gemini Nano isn't available. Mozilla shut down Fakespot in July 2025 and ReviewMeta went offline in early 2026, which says something about how fragile cloud-dependent browser tools are when the underlying API or funding disappears — an on-device product doesn't have that failure mode. The honest caveat: this is a utility people reach for occasionally, not daily, so the free tier has to be good enough to build the habit before the paid vault has anything to sell.

The demand signal is closer to "people keep getting burned by not reading" than "people are asking for this exact tool." A 2026 survey found 70% of respondents had forgotten to cancel a free trial at least once, and separately 42% of consumers admit they've forgotten about a subscription entirely while still being charged for it — the underlying behavior (agree now, deal with consequences later) is well documented even without a dedicated survey on this exact product category.

How to load it in Chrome

1. Open chrome://extensions and turn on Developer mode.
2. Click Load unpacked and select this folder's extension/ directory.
3. Visit any page with real text on it, click the LG icon in the toolbar, and press Brief this page. On a browser without the on-device model downloaded yet, the popup says so instead of guessing — check chrome://on-device-internals to see model status.

How to try the demo

1. Open index.html in any modern browser — no server needed, the sample data is embedded inline for file:// compatibility.
2. Click the LG icon in the mock toolbar, then Brief this page.

The demo always shows the sample brief, since a plain browser tab loading index.html has no on-device model to call — the same fallback path a real install would hit on unsupported hardware. The mock page's insurance notice stands in for whatever content.js would have scraped from a live tab.

Permissions, and why each one

There's no host_permissions entry and no persistent content_scripts block — content.js only ever runs when the user explicitly asks for a brief.

What's in this prototype

• Toolbar popup that extracts the current tab's text, feature-detects the on-device model, and renders a TL;DR, key points, and a flagged "worth a second look" list.
• Context-menu entry that queues an extraction in the background so the brief is ready the next time the popup opens.
• Honest fallback states: a clear message when the on-device model isn't available, and a separate one when the model call itself fails.
• Demo harness with a mock insurance-notice page and the same popup UI, running the same popup.js.
• Paid-tier UI (saved brief vault, upgrade button) is visible but not wired to real checkout or sync — this prototype has no backend.

Roadmap

• Saved brief vault with a lightweight sync backend, so a brief from one device shows up on another.
• Re-check a previously briefed URL and diff it against the saved version, so a quiet ToS edit doesn't slip by.
• A cloud-model fallback for devices that can't run Gemini Nano, gated behind the paid tier since it's the one part of this product with real inference cost.
• Bulk-brief mode for HR and legal teams reviewing many offer letters or vendor contracts at once.

Sources

• Get started with built-in AI | Chrome for Developers — Gemini Nano hardware/OS requirements and the on-device privacy guarantee.
• The Prompt API | Chrome for Developers — the LanguageModel API this extension calls, stable from Chrome 138.
• Subscription Fatigue Statistics 2026 | Readless — 70% of people have forgotten to cancel a free trial at least once.
• Eighth Circuit Vacates the FTC's "Click to Cancel" Rule | WilmerHale — federal cancellation-disclosure rule was struck down in July 2025, leaving state auto-renewal laws as the active backstop.
• Fakespot Chrome Extension Alternative | ReviewAI — Fakespot's July 2025 shutdown and ReviewMeta going offline in early 2026, cited for the cloud-dependency risk argument above.