Book Engine

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Privacy Policy

Last Updated: January 2026

This Privacy Policy describes how YMMV LLC ("Company," "we," "us," or "our") collects, uses, discloses, and protects your personal information when you use Book Engine (the "Service"), accessible at bookengine.xyz. By accessing or using the Service, you acknowledge that you have read, understood, and agree to be bound by this Privacy Policy.

If you have questions about this Privacy Policy or wish to exercise your privacy rights, contact us at support@bookengine.xyz.

1. Information We Collect

1.1 Information You Provide Directly

We collect information you voluntarily provide when using our Service, including:

  • Account Information: Username, email address, and password (stored in hashed form using industry-standard bcrypt encryption)
  • Profile Information: Author name, publisher name, and publisher URL you choose to provide
  • Book Generation Inputs: Plot descriptions, author names, title selections, and other creative inputs you submit for book generation
  • User Preferences: Writing tone preferences and other settings you configure
  • Payment Information: When you make purchases, payment details are collected and processed directly by Stripe, Inc. We store only your Stripe customer identifier, not your full payment card details
  • Communications: Information you provide when contacting our support team

1.2 Information Collected Automatically

When you access or use the Service, we automatically collect certain information, including:

  • Activity Logs: We log user actions including login events, logout events, book creation, book completion, subscription changes, and other account activities
  • Device and Connection Information: IP address, browser type and version, user agent string, operating system, and device identifiers
  • Usage Data: Pages visited, features used, timestamps, referring URLs, and interaction patterns
  • Session Information: Authentication tokens and session identifiers necessary to maintain your logged-in state

1.3 Information from Third Parties

We may receive information from third-party services we integrate with, including:

  • Stripe: Payment confirmation, subscription status, and transaction identifiers
  • Analytics Providers: Aggregated usage statistics and behavioral analytics

2. How We Use Your Information

We use the information we collect for the following purposes:

  • Service Provision: To create and manage your account, process book generation requests, deliver generated content, and provide customer support
  • AI Processing: Your plot descriptions and creative inputs are transmitted to third-party artificial intelligence services (including Anthropic's Claude API, OpenRouter, and OpenAI) solely for the purpose of generating your requested book content
  • Payment Processing: To process subscriptions, one-time purchases, and manage billing through Stripe
  • Communication: To send transactional emails including password reset links, book completion notifications, and important service announcements
  • Security and Fraud Prevention: To detect, prevent, and respond to security incidents, fraud, abuse, and violations of our Terms and Conditions
  • Service Improvement: To analyze usage patterns, diagnose technical issues, and improve the functionality and user experience of the Service
  • Legal Compliance: To comply with applicable laws, regulations, legal processes, or governmental requests

3. Generated Content and AI Processing

3.1 Your Inputs. When you submit plot descriptions, author names, and other creative inputs, this information is processed by third-party AI services to generate your book content. We transmit only the information necessary for content generation.

3.2 Generated Books. The books generated using your inputs are stored on our servers and associated with your account. You retain ownership of the generated content as described in our Terms and Conditions.

3.3 NSFW Content. If you use NSFW book generation features, your age verification confirmation timestamp is recorded. NSFW content is processed by separate AI services (OpenRouter/Grok models) and is subject to the same privacy protections as regular content. We do not review, share, or publicly display your generated NSFW books.

3.4 AI Provider Data Practices. Third-party AI providers may have their own data retention and processing policies. We encourage you to review the privacy policies of Anthropic, OpenRouter, and OpenAI for information about how they handle data transmitted through their APIs.

4. Third-Party Services and Data Sharing

We share your information with third parties only as described below:

4.1 Service Providers

  • Stripe, Inc.: Payment processing and subscription management. Stripe's privacy policy is available at stripe.com/privacy
  • Anthropic (Claude API): AI-powered text generation for regular book content
  • OpenRouter: AI-powered text generation for NSFW book content
  • OpenAI: Supplementary AI processing for certain utility functions
  • Mixpanel: Analytics and usage tracking to understand how users interact with our Service. Mixpanel's privacy policy is available at mixpanel.com/legal/privacy-policy
  • Email Service Provider: Transactional email delivery for password resets and notifications

4.2 Legal and Safety Disclosures

We may disclose your information if we believe in good faith that such disclosure is necessary to:

  • Comply with applicable laws, regulations, legal processes, or governmental requests
  • Enforce our Terms and Conditions or other agreements
  • Protect the rights, property, or safety of YMMV LLC, our users, or the public
  • Detect, prevent, or address fraud, security, or technical issues

4.3 Business Transfers

In the event of a merger, acquisition, reorganization, bankruptcy, or sale of all or a portion of our assets, your information may be transferred as part of that transaction. We will notify you via email and/or prominent notice on the Service of any change in ownership or uses of your personal information.

4.4 With Your Consent

We may share your information for other purposes with your explicit consent.

5. Cookies and Tracking Technologies

5.1 Cookies We Use. The Service uses cookies and similar technologies for the following purposes:

  • Essential Cookies: Required for authentication, session management, and security. These cannot be disabled without breaking core functionality.
  • Analytics Cookies: Used by Mixpanel to collect usage data and help us understand how users interact with the Service.

5.2 Managing Cookies. You can control cookies through your browser settings. Note that disabling essential cookies will prevent you from using authenticated features of the Service.

5.3 Do Not Track. We do not currently respond to "Do Not Track" browser signals, as there is no industry-standard interpretation of such signals.

6. Data Retention

6.1 Account Data. We retain your account information and generated books for as long as your account remains active. If you request account deletion, we will delete or anonymize your personal information within 30 days, except as required for legal compliance or legitimate business purposes.

6.2 Activity Logs. Activity logs containing IP addresses and user agent information are retained for security and fraud prevention purposes and may be kept for up to 24 months.

6.3 Payment Records. Transaction records are retained as required for accounting, tax, and legal compliance purposes, typically for 7 years.

6.4 Backups. Deleted data may persist in encrypted backups for a limited period before being permanently removed.

7. Data Security

We implement appropriate technical and organizational measures to protect your personal information, including:

  • Password hashing using bcrypt with appropriate cost factors
  • HTTPS encryption for all data transmitted between your browser and our servers
  • Secure token-based authentication for password reset functionality
  • Access controls limiting employee access to personal information
  • Regular security assessments and monitoring

However, no method of transmission over the Internet or electronic storage is completely secure. While we strive to protect your personal information, we cannot guarantee absolute security.

8. Your Privacy Rights

Depending on your location, you may have certain rights regarding your personal information:

8.1 General Rights

  • Access: Request a copy of the personal information we hold about you
  • Correction: Request correction of inaccurate or incomplete personal information
  • Deletion: Request deletion of your personal information, subject to legal retention requirements
  • Data Portability: Request a copy of your data in a structured, machine-readable format
  • Withdraw Consent: Where processing is based on consent, withdraw that consent at any time

8.2 California Residents (CCPA/CPRA)

If you are a California resident, you have additional rights under the California Consumer Privacy Act and California Privacy Rights Act:

  • Right to know what personal information is collected, used, shared, or sold
  • Right to delete personal information held by us and by our service providers
  • Right to opt-out of the sale or sharing of personal information (we do not sell personal information)
  • Right to non-discrimination for exercising your privacy rights
  • Right to correct inaccurate personal information
  • Right to limit use and disclosure of sensitive personal information

To exercise these rights, contact us at support@bookengine.xyz. We will verify your identity before processing your request.

8.3 European Economic Area, United Kingdom, and Switzerland (GDPR)

If you are located in the EEA, UK, or Switzerland, you have rights under the General Data Protection Regulation, including:

  • Right of access, rectification, erasure, and data portability
  • Right to restrict or object to processing
  • Right to withdraw consent
  • Right to lodge a complaint with a supervisory authority

Legal Basis for Processing: We process your personal information based on: (a) your consent; (b) performance of a contract with you; (c) compliance with legal obligations; and (d) our legitimate interests in operating and improving the Service, provided such interests are not overridden by your rights.

International Transfers: Your information may be transferred to and processed in the United States, where our servers are located. We rely on Standard Contractual Clauses and other lawful transfer mechanisms where required.

9. Children's Privacy

The Service is not intended for children under the age of 13 (or 16 in the EEA). We do not knowingly collect personal information from children under these ages. If we become aware that we have collected personal information from a child under the applicable age, we will take steps to delete such information promptly.

NSFW features are strictly limited to users who are at least 18 years of age.

If you believe a child has provided us with personal information, please contact us at support@bookengine.xyz.

10. Changes to This Privacy Policy

We may update this Privacy Policy from time to time to reflect changes in our practices, technologies, legal requirements, or other factors. If we make material changes, we will notify you by email (sent to the address associated with your account) or by posting a prominent notice on the Service at least 30 days before the changes take effect.

Your continued use of the Service after the effective date of the revised Privacy Policy constitutes your acceptance of the changes. We encourage you to review this Privacy Policy periodically.

11. Contact Information

If you have questions, concerns, or requests regarding this Privacy Policy or our privacy practices, please contact us:

YMMV LLC
Email: support@bookengine.xyz

For privacy-related inquiries, please include "Privacy" in your email subject line.