Privacy policy

我们存了什么、为什么存、怎么删 · 运营主体：QuantCard · 联系：hello@quantcard.cc · 更新于 2026-10-12

1. What we collect

• Account data: your e-mail address, a salted password hash (scrypt, N=16384), and — if you subscribe — a Paddle subscription reference. We do not see or store card numbers, CVC or bank details; those go to Paddle.
• API keys: stored as a SHA-256 hash plus a 4-character masked hint so you can recognise them. The plaintext key is shown exactly once, at issue time, and is unrecoverable afterwards.
• Usage records: for each billed card we keep the parameters you submitted (source, symbol, timeframe, date range, strategy, cost settings), the resulting verdict numbers, the cost in cards, and a timestamp. This is what makes "same parameters ⇒ cache hit ⇒ not billed again" work, and what lets you re-read a conclusion months later.
• Session cookie: one HttpOnly, SameSite=Lax cookie for the account page. No advertising trackers, no analytics scripts, no third-party cookies on any page.
• Transient IP data: the source IP of each request is used for a per-minute rate-limit bucket held in memory only. It is not written to the database and disappears on process restart.

2. What we never collect

No exchange accounts, no API keys to any exchange, no withdrawal addresses, no trade history from your broker, no KYC documents. The Service reads only public market data (Bybit and Binance public candle endpoints) and, if you ask for it, public funding-rate history.

3. Why we use it

To compute the cards you request, enforce quotas, keep a cache so you are not charged twice, prevent abuse, and satisfy our own accounting obligations. We do not sell or rent personal data, and we do not use it to train anything.

4. Where it lives, who else sees it

The application database (SQLite) runs on our own infrastructure hosted in the United States (Fly.io), encrypted at rest by the volume provider; DNS is served by Cloudflare; payment events arrive from Paddle over HTTPS with an HMAC signature we verify. Sub-processors are therefore: Fly.io (hosting), Cloudflare (DNS/CDN), Paddle (payments). Each is bound by its own terms; we share no personal data beyond what those services need to operate.

5. Retention and deletion

• Cancel a subscription: the account and its cards stay readable (so you can export them and so a future repurchase has history); the API key is refused and quota drops to zero.
• Ask for deletion at hello@quantcard.cc: we delete your user row, sessions, keys and usage rows within 30 days. Paddle keeps transaction records under its own tax-retention obligations.
• Published falsification cards contain market statistics only — no customer identifiers.

6. Your rights

You can request a copy of everything we hold about you, correction, or erasure by writing to the address above; we answer within 30 days and we do not charge. If you are in the EU/UK you also have the right to complain to your supervisory authority; if you are in California, we do not "sell" personal data as CCPA defines it.

7. Security, honestly

Passwords are salted and hashed; keys are hashed; webhook payloads are signature-verified with a timestamp window and replayed events are ignored; quotas are reserved atomically before any computation. No system is immune — if you believe we have been affected by a breach that touches your data, we will tell you what happened and what it exposes.