Privacy
TrendCast is 100% client-side — no servers, no API keys, no telemetry.
TL;DR
TrendCast does not send your data anywhere. There are no servers, no API keys, no telemetry, no analytics, and no tracking. All data is collected and stored locally in your browser.
What Data Is Collected
TrendCast collects public data from the following sources:
| Source | Data | How | Login needed? |
|---|---|---|---|
| Polymarket | Market contracts, odds, volume | Public Gamma API (fetch()) | No |
| Kalshi | Market contracts, odds, volume | Public v2 API (fetch()) | No |
| Trending posts, scores | .json endpoints + DOM scrape | Optional | |
| X (Twitter) | Trending posts, metrics | DOM content script | Yes |
| TikTok | Trending posts, metrics | DOM content script | Yes |
| BBC | Headlines, summaries | Public RSS feed | No |
| CNN | Headlines, summaries | Public RSS feed | No |
| Yahoo Finance | Headlines | Public RSS / DOM | No |
| Google Finance | Headlines | Public RSS / DOM | No |
Where Data Is Stored
All collected data is stored in chrome.storage.local (or
browser.storage.local on Firefox). This is:
- Local to your browser — not synced to any cloud.
- Subject to your browser’s storage limits — typically 10 MB for extensions.
- Automatically pruned — TrendCast keeps a configurable number of history entries (default: 168 = 7 days of hourly data) and removes the oldest entries automatically.
You can check storage usage at any time via the popup’s storage indicator.
What Has Network Access
The extension’s host_permissions in the manifest declare which domains it
can access. These are limited to:
polymarket.com/gamma-api.polymarket.comkalshi.com/external-api.kalshi.comreddit.comx.com/twitter.comtiktok.combbc.com/bbc.co.ukcnn.comfinance.yahoo.comgoogle.com
No other domains are accessed. You can verify this by inspecting the manifest source.
What Is NOT Collected
- ❌ No browsing history
- ❌ No passwords or form data
- ❌ No personal information
- ❌ No telemetry or usage analytics
- ❌ No IP address logging
- ❌ No fingerprinting
Data Export and Deletion
- Export — Use the Export dropdown (CSV/JSON) in the dashboard header to download all collected data.
- Delete — Uninstall the extension to remove all stored data. You can
also clear it via
chrome://extensions→ TrendCast → “Remove”.
Open Source
TrendCast is open source under the MIT license. You can audit every line of code at GitHub.