Privacy

Privacy Policy — Mostly Right browser extension

This Privacy Policy explains what the Mostly Right browser extension ("the extension", "we", "us") collects, why, and the choices you have. It is published by Mostly Right Inc.

The extension has a single purpose: to show live and forecast weather data next to weather-related prediction markets on Kalshi and Polymarket. This policy covers the extension only.

Summary

• —The extension works without an account, and most of what it does happens locally in your browser.
• —We collect pseudonymous usage analytics by default, including an approximate location derived from your IP address. This is not anonymous, it is never sold, and you can turn it off at any time in the extension's Settings.
• —We collect your email address — and optionally a Telegram handle or phone number — only if you choose to submit a data-coverage request or sign up for notifications.
• —We do not collect your trades, balances, payment details, passwords, browsing history, or the contents of the pages you visit.

1. What we collect, and when

a) Usage analytics (on by default; opt-out available)

To understand how the extension is used and to improve it, we collect pseudonymous product-analytics events through our analytics provider, PostHog. These events record actions taken in the extension, for example: the extension was installed; the weather panel was shown; a covered or uncovered market was viewed; a forecast model was changed; the forecast detail view was opened; a coverage request or notification sign-up was made; or an error occurred.

Each event is tied to a pseudonymous identifier generated by our backend — not your name, and not credentials you provide. As part of receiving these events over the internet, PostHog derives an approximate location (such as country, region, and city) from your IP address, and the IP address is retained for this location analytics. Because IP-derived location is personal data, this analytics is pseudonymous with location — it is not anonymous.

Analytics events never include your email address, any free text you type into our forms, your Telegram handle or phone number, or the contents of any market page.

This is on by default and you can turn it off at any time: open the extension's panel, go to Settings, and switch off "Share usage data." When off, no further analytics events are sent.

b) Information you choose to give us (optional)

The extension never requires an account. If — and only if — you choose to use one of these features, we collect:

• —Coverage requests ("Request data"): your email address and the free-text description of the market or data you want, along with the market you were viewing.
• —Notification sign-ups (waitlist): your email address, and/or a Telegram handle, and/or a phone number, depending on how you ask to be notified, along with the market you were viewing.

This information is stored in our backend (Supabase) so we can respond to your request or notify you. We use it for that purpose only.

c) Information stored only on your device

Your preferences (temperature unit, selected forecast model, the forecast trend-line toggle, and your analytics opt-out choice) and short-lived caches of weather data already fetched for the open market are stored locally in your browser. This information stays on your device and is not transmitted to us. Your analytics opt-out is stored locally on a per-device basis and does not sync across your devices.

2. What we do NOT collect

• —No financial or trading data. Although the extension runs on Kalshi and Polymarket, it does not read or collect your trades, positions, balances, order history, or any payment information. It only identifies which weather market is on screen so it can show the matching weather data.
• —No passwords or credentials.
• —No browsing history. The extension detects in-page navigation only on Kalshi and Polymarket so it can refresh the panel for the market you're viewing; it does not record or transmit the pages you browse elsewhere.
• —No page content. The current market page is read locally to identify the market and its weather station; that page content is not transmitted off your device.
• —No health data, and no personal communications.

3. Third-party weather data sources

To populate the panel, the extension's background service worker retrieves weather data from public sources: NOAA / National Weather Service aviation weather (aviationweather.gov), the Iowa Environmental Mesonet (mesonet.agron.iastate.edu), Open-Meteo (open-meteo.com), and, for Polymarket, Polymarket's public market metadata API (gamma-api.polymarket.com) to map a market to its weather station.

These are outbound requests for weather and market-metadata only — we do not send your email, your form text, or your analytics identity to them. As with any web request, the receiving service necessarily sees the connecting IP address, and each provider's handling of that request is governed by its own privacy policy.

4. Who we share data with

We do not sell your data, and we do not share it for advertising. We use a small number of service providers (data processors) strictly to operate the extension:

• —PostHog — product analytics (the usage events and IP-derived location described in §1a).
• —Supabase — our backend, which stores the coverage requests and notification sign-ups you choose to submit (§1b).

We may disclose information if required by law, or to protect our rights, users, or the public.

5. Your choices and controls

• —Turn off analytics: Extension panel → Settings → switch off "Share usage data."
• —Delete your saved contact: The extension's Settings include a control that clears the email/Telegram/phone contact saved for notifications, both locally and from our backend on a best-effort basis.
• —Access, correction, or deletion: To request access to, correction of, or deletion of information associated with you (including coverage requests or notification sign-ups), contact us at [email protected]. Depending on where you live, you may have rights under laws such as the EU/UK GDPR or the CCPA/CPRA; we honor applicable requests.
• —Uninstalling the extension stops all collection and removes locally stored preferences and caches.

6. Data retention

We keep analytics data only as long as needed for product analysis, and contact information (email/Telegram/phone) for as long as needed to respond to your request or to send the notifications you asked for, after which it is deleted on request or when no longer needed. Locally stored preferences and caches remain on your device until you clear them or uninstall the extension.

7. Children

The extension is intended for adults using prediction-market sites and is not directed to children. We do not knowingly collect personal information from children.

8. International users

We operate from the United States, and information may be processed in the United States and other countries where our service providers operate. By using the extension you understand that your information may be processed in these locations.

9. Changes to this policy

We may update this policy as the extension evolves. We will revise the "Last updated" date above and, for material changes, take reasonable steps to make the update noticeable. The Chrome Web Store listing's privacy disclosures will be kept consistent with this policy.

10. Contact

Questions or requests about this policy or your data: