Focus — Jev-powered distraction blocker

Stay productive. Focus uses TypeSafe's Jev System One classification model (docs) through OpenRouter's Decisions API to decide whether a domain is distracting, and blocks it.

How it works

1. On each top-frame navigation (webNavigation.onBeforeNavigate + tabs.onUpdated fallback for SPAs), the background service worker extracts the domain.
2. Allowlist / blocklist overrides win first. Fresh cached verdicts (7 days) win second.
3. Otherwise it calls Jev via OpenRouter:

POST https://openrouter.ai/api/alpha/decisions
Authorization: Bearer <OPENROUTER_API_KEY>
Content-Type: application/json

{
  "model": "typesafe/jev-1.13",
  "state": "Domain: youtube.com\nFull URL: https://www.youtube.com/\nPage title: YouTube\nUser goal: stay productive…",
  "questions": {
    "site_category": {
      "type": "choice",
      "instructions": "Is visiting this website productive for focused work, or is it distracting?",
      "criteria": {
        "productive": "Work, study, documentation, coding, email, calendar, maps, …",
        "distracting": "Social media feeds, short-video doomscrolling, entertainment, gaming, gambling, …"
      }
    }
  }
}

4. If answers.site_category.choice === "distracting" and P(distracting) >= threshold (default 0.6), the tab is redirected to blocked.html, which shows the probability, confidence, and model.
5. Without an API key (or if the API fails), a small offline heuristic list keeps the extension useful until you configure a key.

This mirrors the TypeSafe POST /v1/systemone shape ({ state, model, questions } with a Choice classification primitive); OpenRouter just serves it at /api/alpha/decisions with OpenRouter auth.

Files

File	Purpose
manifest.json	Shared MV3 manifest (Chrome, Firefox, and Safari), permissions, options page
background.js	Navigation interception, Jev classification, caching, blocking
popup.html / popup.js	Toolbar popup: current-site verdict, enable toggle, allow/block, re-check
options.html / options.js	Extension dialog: OpenRouter API key, model, threshold, lists, cache
blocked.html / blocked.js	Block interstitial
styles.css	Shared dark theme
icons/	Extension icons
scripts/package-safari.sh	Generates the macOS Safari host app and Xcode project

Install (Chrome / Edge / Brave)

1. Open chrome://extensions, enable Developer mode.
2. Load unpacked → select this Focus folder.
3. Click the 🎯 toolbar icon → Settings & API key.
4. Paste your OpenRouter key (from openrouter.ai → Keys) → Save settings → Test API key.
5. Browse. Distracting domains redirect to the Focus blocked page.

Install (Firefox)

1. Open about:debugging#/runtime/this-firefox → Load Temporary Add-on → pick manifest.json.
2. Open Add-ons → Focus → Preferences to set the API key.

Install (Safari 15.4+)

The Safari version uses the same JavaScript, HTML, and CSS as Chrome, so its filtering, settings, cache, popup, and blocked page behave identically. The packaging script removes Safari's unsupported options_ui.open_in_tab preference from its staged manifest only.

Temporary development install

1. In Safari, open Settings → Advanced and enable Show features for web developers.
2. Open Settings → Developer, enable Allow unsigned extensions, then click Add Temporary Extension… and select this Focus folder.
3. Open Settings → Extensions → Focus and allow access to All Websites.
4. Open the Focus toolbar popup and configure the API key as above.

Safari removes temporary extensions after 24 hours or when Safari quits.

Build a macOS app

Install the full Xcode app, then run:

BUNDLE_IDENTIFIER=com.example.Focus ./scripts/package-safari.sh

This creates a macOS host app and Xcode project under build/safari. Open the generated project, select your development team if signing is required, and run the Focus (macOS) scheme. Enable Focus and grant All Websites access in Safari's extension settings.

Use a unique reverse-DNS BUNDLE_IDENTIFIER ending in .Focus that belongs to your Apple developer account. The script refuses to overwrite an existing output directory so it does not discard Xcode signing configuration. To generate a fresh project, remove the old output directory and run the command again.

The script stages only extension runtime files and asks Apple's safari-web-extension-packager (or its older safari-web-extension-converter name) to generate the native wrapper. The wrapper is generated rather than committed so all browsers continue to share one behavior implementation.

Configure

• Model: typesafe/jev-1.13 (pinned, default) or ~typesafe/jev-latest (auto-update).
• Threshold: minimum P(distracting) to block. Lower = stricter.
• Allowlist / blocklist: one domain per line, www. stripped, subdomains match.
• Cache: per-domain verdicts are cached for 7 days.

Privacy

• The API key is stored in chrome.storage.sync and sent only to https://openrouter.ai. Safari implements this storage area locally but does not sync it between devices.
• Each new domain sends { domain, full URL, page title } as Jev state. No page content is sent.