4tune Privacy Policy
This policy describes how the 4tune browser extension ("4tune," "we," "the extension") handles your data. It's written to be accurate and specific to how 4tune actually works, not generic boilerplate.
The short version
4tune has no server, no backend, and no database of its
own. Everything it stores — your API keys, your cached
balances, your preferences — lives only in your own browser, on
your own device, using Chrome's built-in chrome.storage.local
API. We (the developer) never see it, never receive it, and have
no way to access it. The only places your data ever travels to
are:
- The trading/exchange platforms you connect (Trading 212, Alpaca, Binance, Kraken) — because 4tune needs to ask them for your balance, using an API key you provide.
- Frankfurter (frankfurter.dev) — a free, public currency-exchange-rate service, and only to ask for exchange rates (e.g. "what is 1 EUR in USD"). No personal or financial data is sent to Frankfurter — just currency codes.
That's the entire list. No analytics, no advertising networks, no third-party tracking, no data broker, nothing else.
What data 4tune accesses and stores
| Data | Where it's stored | Why |
|---|---|---|
| API keys/secrets you enter for each platform | chrome.storage.local (your device only) |
To authenticate requests to that platform on your behalf |
| Cached account balances, positions, and fees | chrome.storage.local (your device only) |
So the popup/dashboard can display your portfolio without re-fetching every time |
| Daily portfolio value snapshots (up to 365 days) | chrome.storage.local (your device only) |
To power the performance trend charts |
| Preferences (theme, display currency, refresh interval, view selections) | chrome.storage.local (your device only) |
To remember your settings between sessions |
4tune does not access your browsing history, the content of other websites you visit, your bookmarks, your other browser tabs, or anything outside of what's listed above. Its permissions are scoped specifically to the API domains of the platforms it connects to (Trading 212, Alpaca, Binance, Kraken, Frankfurter) — it cannot read or modify other websites.
How your data is used
Solely to display your own portfolio information back to you: fetching balances, computing totals and profit/loss, converting currencies, and rendering charts. Nothing is used for any purpose beyond what's visibly happening in the extension's own interface.
Who your data is shared with
Only the parties listed in the table above, and only because you directed 4tune to talk to them by entering your own API key for that platform. We (the developer) do not operate a server that receives, stores, logs, or has visibility into any of this data. There is nothing for us to share, sell, or be breached, because we never have it in the first place.
We do not use or share your data for advertising, retargeting, or any interest-based purpose, and no human — including us — reads your data. We comply with the Chrome Web Store's Limited Use requirements: data 4tune accesses is used only to provide the portfolio-tracking functionality described here and in the extension's own listing, and for no other purpose.
Data retention and deletion
Because everything is stored locally on your device, deleting your data is entirely in your control, in a few ways:
- Disconnect a single platform: click the ⚙ on any platform's card and use the "Disconnect" option — this immediately removes that platform's stored key and cached data.
- Reset performance history: the dashboard has a "Reset history" control that clears stored trend/snapshot data.
- Uninstall the extension: Chrome automatically deletes all of
chrome.storage.localfor an extension when it's uninstalled — this removes everything 4tune ever stored, immediately and completely.
There is no account to close and no request to send us, because there is no copy of your data anywhere except your own browser.
Security
- All communication between 4tune and the platforms it connects to (and Frankfurter) happens over HTTPS.
- 4tune's guide explicitly recommends creating read-only API keys for every platform, with trading/withdrawal permissions left disabled — this limits what could go wrong even in a worst case.
- Because there is no server, there is no central database of user API keys that could be breached in the way a typical SaaS product's could. The realistic risk surface is the security of your own device and browser profile, same as any locally-stored browser data.
Children's privacy
4tune is not intended for use by anyone under the age of 18, or the age of legal majority in their jurisdiction if higher. We do not knowingly collect data from children.
Your rights (GDPR and similar)
Because 4tune stores data only on your own device and we have no copy of it, most data-subject rights (access, rectification, erasure, portability) are inherently already fully in your hands — you can view, edit, or delete anything 4tune stores at any time through the extension itself, or by uninstalling it. If you have questions about this, contact us using the details below.
Changes to this policy
If this policy changes, we'll update the "Last updated" date above. Since 4tune has no accounts or login, we don't have a way to email you directly about changes — check this page periodically, or watch the extension's Chrome Web Store listing for version notes.
Contact
4tune.tracker@gmail.com
This policy is a draft prepared with AI assistance based on 4tune's actual code and architecture. It is not legal advice. Given this product handles financial API credentials and GDPR applies to EU users, have this reviewed by a qualified lawyer before publishing or submitting to the Chrome Web Store.