Privacy Policy & Security Policy

1. Introduction & Who We Are

Briefklar is an AI-powered document analysis platform built to help migrants, expats, international students, and anyone navigating official correspondence in a foreign country. We analyse government letters, administrative documents, and official notices — translating complex bureaucratic language into plain, actionable explanations across 30+ languages.

This document sets out both our Privacy Policy and our Security Policy. Together, they explain what data we collect, why we collect it, how we protect it, and your rights as a user.

2. Data We Collect

We collect only what is necessary to provide the service. Below is a full account of every category of data Briefklar collects.

2.1 Account Data

When you create an account via Clerk (our authentication provider), we receive and store:

• Full name and email address
• Authentication method (email/password or social login)
• Account creation timestamp
• Preferred language and country settings

2.2 Document Data

When you upload a letter or document for analysis:

• The document file (image, PDF, or text) is processed and stored temporarily in a private, encrypted storage bucket
• OCR-extracted text from your document
• AI-generated analysis, explanation, and suggested reply
• Upload timestamp and document metadata (type, size)
• Urgency level, deadline dates, and required actions identified by the AI

2.3 Usage Data

• Pages visited and features used within the app
• Number of letters processed per billing period (for plan enforcement)
• Dashboard visit count (used only to recommend the best notification method)
• Device type and browser (for compatibility purposes)

2.4 Subscription & Payment Data

Payment processing is handled entirely by Stripe. Briefklar never sees or stores your card details.

• Subscription plan (Free, Pro, or Family)
• Subscription status and billing period
• Stripe Customer ID (a reference identifier, not payment data)
• Subscription start and end dates

2.5 Notification & Consent Data

If you opt in to deadline reminders, we collect and store:

• Your consent decision and the timestamp it was given
• Your preferred notification method (email, browser push, or in-app)
• Your notification email address (may differ from your login email)
• Browser push subscription endpoint (encrypted at rest)
• A hashed version of your IP address at consent time (SHA-256 — never the raw IP)
• Consent withdrawal timestamp if you later opt out

2.6 Referral & Partner Data

If you join the Briefklar Partner Program:

• Full legal name
• IBAN (for commission payouts)
• Tax ID — Steuernummer or USt-IdNr (required under German tax law)
• Partner terms acceptance timestamp
• Commission records, referral records, and payout history

Commission and payout records are kept for 10 years under German commercial law (Handelsgesetzbuch § 257).

2.7 Security & Technical Data

• SHA-256 hashed IP addresses (for rate limiting and security — never raw IP)
• API request timestamps and response codes (for monitoring)
• Rate limit counters (reset hourly)
• Error logs (no personal content included)

3. Legal Basis for Processing

We process your data only where we have a lawful legal basis under GDPR Article 6.

4. How We Use Your Data

4.1 Core Service Delivery

• Processing and analysing your uploaded documents using AI (Anthropic Claude)
• Generating plain-language explanations in your chosen language
• Generating formal reply letters in the official language of the document
• Enforcing usage limits per subscription plan
• Providing letter history and document management

4.2 Notifications & Deadline Tracking

• Sending deadline reminders via your chosen method (email, browser push, or in-app bell)
• Using your visit count only to recommend the most suitable notification method
• Visit count and behavioral signals are never used for marketing, advertising, or profiling

4.3 Payments & Subscriptions

• Processing subscription payments via Stripe
• Enforcing plan-based credit limits
• Calculating and paying affiliate commissions to Partner Program members

4.4 Security & Abuse Prevention

• Rate limiting API requests to prevent abuse (max 10 uploads/hour per user)
• Validating uploaded files to prevent malicious uploads
• Detecting and blocking prompt injection attempts
• Monitoring for unusual activity patterns

5. Notification System & GDPR Compliance

5.1 Consent-First Architecture

Briefklar's deadline reminder system is built on a consent-first model. No notification detection, no signal analysis, and no browser push prompt will ever appear until you have explicitly clicked “Yes, remind me” on our consent screen. Dismissing the screen or clicking “No thanks” means zero notification activity occurs.

5.2 Smart Method Detection

After you give consent, the system checks three signals to recommend the best notification method:

• Browser push notification support and permission status
• Whether you have a verified email address on your account
• How many times you have visited the dashboard (visit count)

These signals are used solely to recommend a method. You can override the recommendation at any time.

5.3 Withdrawing Consent

You can withdraw notification consent at any time in Settings > Notifications. Withdrawal takes effect immediately — no delay, no confirmation email required. Your consent record is retained for 3 years for legal audit purposes, but no further notifications are sent.

5.4 Email Reminders Compliance (German UWG)

Every deadline reminder email sent by Briefklar includes a one-click unsubscribe link. This link works without requiring you to log in. Clicking it immediately disables all email reminders for your account. This complies with both GDPR and the German Gesetz gegen den unlauteren Wettbewerb (UWG).

6. Data Sharing & Third Parties

Briefklar uses a small number of carefully selected third-party services to operate. We share the minimum data necessary with each.

All third-party processors have signed Data Processing Agreements (DPAs) as required by GDPR Article 28. All data processing occurs within the European Union or under adequate transfer mechanisms.

We do not share your data with governments, law enforcement, or any other party except where required by law — in which case we will notify you where legally permitted to do so.

7. Data Retention

We apply soft-delete across all records — data is flagged as deleted and made inaccessible before permanent deletion at the end of the retention period.

8. Your Rights Under GDPR

As a data subject under the GDPR, you have the following rights. All requests are processed within 30 days at no charge.

To exercise any right, contact: privacy@briefklar.de

9. Security Policy

Briefklar has undergone a comprehensive security audit. The following measures are active in production.

9.1 File Upload Security

• Maximum file size: 20 MB per upload
• File type validation using magic number (byte signature) verification — not just file extension
• All uploaded files stored in a private storage bucket with no public URL
• Signed access URLs expire after 1 hour
• File names are sanitised before storage to prevent path traversal attacks

9.2 Input Validation & Sanitisation

• All user inputs validated for length, format, and content on both client and server
• Maximum lengths enforced: names (200 chars), addresses (500 chars), instructions (2,000 chars), letter text (50,000 chars)
• Control characters and null bytes are stripped from all inputs
• Email addresses validated with regex on both client and server

9.3 Prompt Injection Prevention

• All user-submitted text is sanitised before being included in AI prompts
• Dangerous patterns (system:, ignore previous instructions, etc.) are detected and neutralised
• User content is isolated using XML tags to prevent it from being interpreted as instructions

9.4 Rate Limiting

9.5 Data Encryption

• All data in transit encrypted via TLS 1.2+ (HTTPS enforced)
• Database encrypted at rest (Supabase AES-256)
• Web Push notification credentials encrypted before database storage
• IP addresses stored only as SHA-256 hashes — the raw IP address is never written to any database
• Unsubscribe tokens generated using cryptographically secure random bytes

9.6 Authentication & Access Control

• Authentication managed by Clerk — industry-standard session management
• All API routes verify authenticated Clerk session before processing
• Supabase Row Level Security (RLS) enforced — users can only access their own rows
• Admin routes require explicit admin role verification
• Unsubscribe route is the only exception — token-based access without login (GDPR compliance)

9.7 Content Security & Headers

• Content Security Policy (CSP) headers configured to prevent XSS attacks
• Cross-Origin-Opener-Policy (COOP) header set to same-origin
• HSTS (HTTP Strict Transport Security) enforced in production
• Clickjacking protection via X-Frame-Options and CSP frame-ancestors

10. Subscription Plans & Usage Limits

11. Cookies & Tracking

We do not use advertising cookies, tracking pixels, or any analytics cookies. We do not work with advertising networks. Referral attribution cookies are only set after cookie consent is obtained, in compliance with the German TTDSG.

12. Children's Privacy

Briefklar is not directed at children under 16 years of age. We do not knowingly collect personal data from anyone under 16. If you believe a child has provided us with personal data, please contact privacy@briefklar.de immediately and we will delete it.

13. AI Analysis Disclaimer

14. Changes to This Policy

We may update this Privacy & Security Policy from time to time. When we make material changes, we will:

• Display a prominent notice in the app dashboard
• Send an email notification to all registered users
• Update the “Last Updated” date at the top of this document
• Maintain previous versions accessible at briefklar.de/legal/archive

Continued use of Briefklar after the effective date of changes constitutes acceptance of the updated policy. If you do not agree with changes, you may close your account at any time.

15. Contact & Data Requests