Your data
Trade Buty does not collect personal data. All learning progress (read status, quiz results, replay history) is stored locally in your browser's localStorage. No data is sent to our servers unless you choose to log in with email.
Share, invite and AI entry interactions may print a small allowlisted debug event to your browser's developer console. These events stay on your device, are not sent to us, and do not include raw invite codes, email addresses, chapter titles, full URLs or free text.
If a page crashes or an action fails, your browser may send a minimal diagnostic signal to our own same-origin endpoint (/api/error-reports). It carries only a coarse level (fatal / recoverable), a fixed scope name (for example route-error), an error type name, and — for server-rendered crashes — Next.js's opaque digest hash. It never contains the error message, stack trace, page URL, account identity, or any free text you typed. These signals are written to short-lived server logs for debugging only: not stored in our database, not linked to your account, and not used for tracking or advertising.
When you log in via email magic link, your email address is stored by Supabase Auth (our authentication provider, hosted in the US). Your learning progress is synced to Supabase only to enable cross-device access.
We use a single cookie (tb-lang) to remember your language preference. No tracking cookies, no analytics cookies, no third-party cookies.
Supabase (authentication + database), Binance public API (market data), SenseNova (AI chat), SiliconFlow (AI embeddings). Each service is used only when you explicitly interact with the feature.
Download a JSON copy of your local learning progress, quiz results, replay history, and sync status. All local browser storage entries are included.
Local data lives only in your browser's localStorage and stays until you clear site data. Before you log in our servers keep no personal profile — the only request that reaches us without an account is the anonymous crash diagnostic above, which is never persisted to the database. Built-in trims keep the local footprint small: the study-time ledger keeps the most recent 90 days and market replay history keeps the latest 100 rounds.
Cloud data (only after you log in) is kept while your account exists so learning progress survives across devices. Pending offline writes are retried until they sync or the account is removed. To delete everything, sign in and use the account menu → Delete account: it removes all cloud rows for your account (progress, mistake log, quiz scores, replay history, settings) and clears local data on that device.
For privacy concerns, open an issue at github.com/Sun1090/trade-buty.