Your data, our handling rules

This policy explains what Kline Vision collects when you use https://www.klinevision.ai, why we collect it, who we share it with, and what choices you have. If anything below is unclear, contact support@klinevision.ai.

Last updated: 2026-07-13

1. Who we are

Kline Vision ("we", "us", "the Service") is the operator of klinevision.ai, an AI-assisted technical-analysis tool for stock K-line screenshots. The Service is provided for educational and research purposes only and is not investment advice.

2. What we collect

Account data — email address (when you sign up via Supabase magic link or Google OAuth) and a generated user ID. We do not store your password. Uploaded charts — the K-line screenshot you submit for analysis. Images are processed by Google Gemini Vision API and stored alongside the resulting analysis so you can revisit it from your history. Usage data — pages visited, buttons clicked, analysis events, masked session replay events, and basic device info. We use this to understand product usage and to optimize advertising. Payment data — when you subscribe, Stripe collects your card details and customer metadata. We never see or store your card number; we only receive a Stripe customer ID and subscription status. Optional integrations — if you connect Telegram, we store your Telegram chat ID to deliver alerts you opted into.

3. Why we collect it

To run the Service: authenticate you, run AI analysis on your charts, store your history, and deliver subscription features. To bill: process subscription payments via Stripe. To improve the product: anonymous, aggregated metrics about which features are used and where users get stuck. We also use masked session replay to understand navigation and usability issues without sending raw chart images, free-text messages, emails, payment details, magic links, or raw analysis IDs. To show and measure ads: with your consent (where required), we run remarketing and conversion measurement on Meta (Facebook/Instagram) and Google. See section 6.

4. Legal basis (GDPR / UK GDPR)

Performance of contract — to provide the Service you signed up for. Legitimate interest — for security logs, fraud prevention, aggregated product analytics, and masked usability replay. Consent — for advertising cookies and pixels (Meta Pixel, Google Analytics in advertising mode). You can withdraw consent at any time via your browser controls or our cookie banner where shown.

5. Who we share data with

We share only what is necessary, with the following processors: Supabase — authentication and database hosting. Google Gemini API — vision analysis on your uploaded charts. Stripe — payment processing and subscription management. Vercel — application hosting and edge delivery. Google Analytics — usage analytics. PostHog — product analytics and masked session replay. Meta Platforms (Facebook/Instagram) — Meta Pixel and Conversions API for measuring ad performance. EODHD, Tushare, Finnhub — third-party market-data providers for symbol context. Telegram — message delivery if you opted into Telegram alerts. We do not sell your personal data to third parties.

6. Cookies, pixels, and advertising

We use first-party cookies for authentication and session management. We use Google Analytics 4 and PostHog to understand product usage in aggregated, mostly anonymized form. PostHog may record masked session replays so we can debug UX issues; text, form inputs, images, canvas content, and other sensitive areas are masked or blocked before replay capture. We use the Meta Pixel and Conversions API to measure the effectiveness of advertising and to build similar-audience targeting on Meta. The Pixel sends events such as PageView, ViewContent, Lead, and Purchase. Personally identifying values such as email are hashed (SHA-256) before transmission. You can opt out of Meta personalized advertising at https://www.facebook.com/ads/preferences and Google personalized advertising at https://adssettings.google.com.

7. Data retention

Account and subscription records are kept for as long as your account is active and for up to 24 months after deletion to satisfy tax and audit requirements. Uploaded chart screenshots and analysis history are kept until you delete them or close your account. A confirmed research thesis that you delete is hidden immediately from product and notification surfaces, excluded from personal statistics, and physically removed with its verification checks after 30 days. A verified privacy deletion request may remove it sooner. Deleting a thesis does not by itself delete its separate source analysis. Server logs are retained for up to 90 days for security and debugging.

8. Your rights

Depending on where you live, you have the right to access, correct, export, or delete your personal data, and to object to or restrict certain uses. To exercise any of these rights, email support@klinevision.ai from the address on your account. We will respond within 30 days. You may also withdraw advertising consent without affecting access to the Service.

9. International transfers

Some of our processors (Vercel, Stripe, Google, Meta, PostHog, Supabase) may process data in the United States or other regions. Where required, we rely on Standard Contractual Clauses or equivalent safeguards.

10. Children

The Service is not directed at users under 16. We do not knowingly collect data from children. If you believe a child has used the Service, contact us and we will delete the account.

11. Changes to this policy

We may update this policy as the Service evolves. Material changes will be announced on the site and reflected in the "Last updated" date above. Continued use after a change means you accept the updated policy.

12. Contact

Questions, complaints, or data requests: support@klinevision.ai.