Privacy Policy

Korean Diary AI ("we", "us") is operated by Jaeho Chung. This policy explains what information we collect, how we use it, and the choices you have. Business location is disclosed upon request without delay (see Commerce Disclosure).

Account information: your email address and, if you sign in with Google, the basic profile information (name, email, avatar) Google provides via OAuth.

Content you submit: the Korean diary entries and text you submit for correction, and the corrections, natural-expression suggestions, and learning summaries generated from them.

Usage and billing data: your Korean level, daily correction counts, subscription plan, and Stripe-related billing identifiers (customer ID, subscription ID, plan, expiration date). We never store your full card number — Stripe handles payment details directly.

Analytics data: page views and product usage events collected via Google Analytics 4, PostHog, and Microsoft Clarity (cookies and similar technologies), used to understand how the Service is used and to improve it.

To provide the Service — authenticate you, store your diary entries and corrections, enforce daily free-plan limits, and process subscription payments.

To generate corrections — your submitted diary text is sent to Anthropic's Claude API for AI-based correction. This text is processed to return grammar corrections, natural alternatives, and a learning summary, and is subject to Anthropic's own data-handling terms as our processor.

To operate the business — process payments via Stripe, communicate with you about your account, and analyze aggregate usage trends via GA4, PostHog, and Clarity.

We share data only with the service providers needed to operate Korean Diary AI, each acting as a data processor on our behalf:

• Supabase — hosts our database and authentication (stores your account, diary entries, and corrections).

• Anthropic (Claude API) — receives the diary text you submit, in order to generate corrections.

• Stripe — processes payments and stores billing/payment details.

• Google — provides OAuth sign-in if you choose to continue with Google.

• Google Analytics 4, PostHog, Microsoft Clarity — receive usage/analytics events and cookies.

We do not sell your personal information.

Your account and diary entries are retained for as long as your account is active.

Free plan: entries older than 7 days are hidden from your History view (a soft filter), but are not deleted — upgrading to Pro restores full access to your history.

Pro / Annual plan: your full writing history is retained and accessible without the 7-day limit for as long as your subscription (or account) remains active.

If you delete your account or request deletion (see Section 7), we delete your diary entries and personal data from our active database, except where retention is required for legal, tax, or fraud-prevention purposes (e.g., billing records).

We use cookies and similar technologies from Google Analytics 4, PostHog, and Microsoft Clarity to understand aggregate usage and improve the Service. You can control cookies through your browser settings; disabling them may affect analytics but not core functionality.

You may request access to, correction of, or deletion of your personal data at any time by emailing kdiaryai.help@gmail.com. We will respond and act on verified requests without undue delay.

You may also delete individual diary entries yourself from within the app, or cancel your subscription at any time from account settings.

Our service providers (Supabase, Anthropic, Stripe, Google, GA4, PostHog, Clarity) may process data outside your country of residence. Each provider maintains its own safeguards for cross-border data transfer.

Korean Diary AI is not directed at children under 13, and we do not knowingly collect personal information from them.

We may update this Privacy Policy from time to time. Material changes will be reflected by updating the date below.

Questions or requests regarding this Privacy Policy can be sent to kdiaryai.help@gmail.com.