Privacy Policy — NODUS HN Radar

🔍 1. Overview

NODUS HN Radar is a fully local-first browser extension. It enhances reading experience on news.ycombinator.com and surfaces rising posts via the public Hacker News API. There is no server, no account, no login, no cloud sync, and no telemetry.

This is a sibling product to the main NODUS extension (AI conversation capture) and to NODUS YT Radar. Each has its own separate privacy policy:

Main NODUS — privacy.html
YT Radar — yt-radar-privacy.html
HN Radar — this document

HN Radar connects to three endpoints — two belonging to Hacker News itself, and one small NODUS server used only for a footer promotion:

required news.ycombinator.com

The site you are reading. The content script enhances pages you load yourself — no proactive fetching.

required hacker-news.firebaseio.com

Hacker News's public Firebase API. Used to fetch trending lists (Top / Show / Ask / Best) and individual item details for the Radar dashboard.

new · v0.16.15 worker-ph-radar.mmcarvalho-dev.workers.dev

Powers a rotating banner in the extension's footer that cross-promotes other NODUS extensions (e.g. PH Radar). The extension sends only an opaque promotion ID when a banner is shown or clicked, used solely to count aggregate impressions/clicks. No personal data, browsing history, or Hacker News content is ever sent to this server.

💾 2. Data stored locally on your device

All of the following is stored in chrome.storage.local and never sent anywhere unless described in Section 3.

settings

Your preferences: theme, font size, reading width, highlight toggles, interface language, translation settings, zebra color/intensity, etc.

visited

Map of HN post IDs you have clicked from the front page, with timestamps. Used to gray out visited posts. 30-day TTL with auto-pruning.

pinned

Posts you explicitly pinned via the 📌 icon: id, title, url, domain, score snapshot, comments count, age text, tags, and pinned timestamp.

collapsedCards

Map of pinned card IDs that you collapsed in the side panel, so the state persists across sessions.

recentTags

List of the last 40 tag names you used, for the autocomplete suggestions when adding a new tag.

mutedDomains

List of domains you chose to mute. Posts from those domains are hidden in the Radar.

radar

Snapshots of HN post data (score, comment count) over time, used to compute velocity. Auto-pruned: only posts currently in trending lists are kept.

opActiveCache

Cache of "Original Poster has replied" detection results per post ID. 10-minute TTL.

comments_<postId>

Cached top comments for posts you hovered to preview. 10-minute TTL.

Uninstalling the extension automatically clears all of the above. There is no user account, no email collection, and no way for NODUS to identify you from any of this data.

🌐 3. External endpoints explained

The extension only fetches from three domains, all declared in host_permissions and visible to your browser before install.

3a. Hacker News website

https://news.ycombinator.com/* content script only

The content script injects CSS and small DOM enhancements (pin buttons, type badges, translation buttons) on pages you load yourself. The extension does not proactively fetch HN pages in the background.

Data sent to HN by the extension: none beyond what your browser already sends when you load the site.

3b. Hacker News public Firebase API

https://hacker-news.firebaseio.com/v0/topstories.json required

Returns the array of currently trending post IDs. Same source the official HN front page uses.

Data sent: nothing identifying — just the request.

…/v0/{best,show,ask}stories.json required when tab active

Same as above for the Best, Show HN and Ask HN tabs of the Radar dashboard.

…/v0/item/<id>.json required per post

Fetches public details for each post or comment shown in the Radar or in a hover preview.

Data sent: the post ID. No identifier of you.

Hacker News and Y Combinator may log these requests according to their own policies. The extension itself adds no headers, cookies, or auth.

3c. NODUS ecosystem cross-promo (worker-ph-radar)

GET https://worker-ph-radar.mmcarvalho-dev.workers.dev/cross-promo?target=hn-radar required for footer banner

Fetches the pool of active NODUS ecosystem promotions to show in the extension's footer (e.g. an ad for PH Radar). Refreshed at most every 10 minutes, cached locally in between.

Data sent: nothing identifying — just the request. No post IDs, browsing data, or HN content.

POST …/cross-promo/impression · POST …/cross-promo/click optional · technical/interaction only

Sent when a footer promotion is shown or clicked, purely to count aggregate impressions/clicks for that promotion.

Data sent: a single opaque promotion ID (e.g. cross-hn-to-ph). No user identifier, IP-based profile, or personal data of any kind is attached or stored against you.

🌐 4. In-browser translation

Translations happen entirely on your device. HN Radar uses Chrome's built-in Translator API (Chrome 138+), which downloads a small language model locally on first use and translates text without sending it to any server.

This means:

No text leaves your browser when translating.
No API key, no cost, no usage tracking.
Translation works offline once the language pair model is downloaded.
Cache of translations is local-only and cleared with the extension.

If your browser does not support the Translator API (Firefox or older Chrome), the translation features simply do nothing — there is no fallback to any cloud translation service.

🚫 5. What we never do

Sell your data to any third party
Send anything that identifies you to NODUS servers (only an opaque promotion ID, for the footer banner's aggregate stats)
Track which posts you read, click, or pin
Track websites you visit outside news.ycombinator.com
Use third-party analytics or advertising SDKs
Read or store your HN comments, replies, or account data
Access microphone, camera, clipboard, or downloads
Inject ads or affiliate links
Require an account, login, or email
Sync your tags, pins, or preferences to any cloud

⚖️ 6. Your rights (LGPD / GDPR / CCPA)

HN Radar is compliant with the Brazilian LGPD, the EU GDPR, and compatible with CCPA. Since all data is local and the extension does no profiling or cross-site tracking, most rights are exercised directly through your browser.

Rights you have

Access — All local data is visible at chrome://extensions → HN Radar → Inspect views → Application → Storage
Deletion — Uninstalling the extension clears everything. You can also clear just the extension's data in your browser settings
Portability — Local data is plain JSON in chrome.storage.local; you can export it from DevTools
Opt-out — Disable the Lens master toggle at any time to stop all DOM modifications. Close the side panel to stop Radar fetches

Legal basis for processing

Reading the public HN site and the public HN Firebase API is processed under legitimate interest (delivering the reading-layer feature you opted into by installing the extension). No personally identifying data is processed at all.

✉️ 7. Contact

For privacy questions or feature requests:

📧 Email

[email protected]

🌐 Project site

nodus-ai.app/hn-radar

This policy may be updated when new features are added. Material changes will be noted in the extension's release notes on the Chrome Web Store and Firefox AMO. Continued use after a policy change constitutes acceptance of the updated policy.