MasterProse

Privacy Policy

masterprose.com

Effective Date: February 19, 2026
Your privacy matters to us. This Privacy Policy explains what personal information MasterProse collects when you use our AI writing platform at masterprose.com, how we use and protect that information, and what choices you have. Please read this policy carefully. By using the Service, you agree to the practices described here.

1 Who We Are

MasterProse ("we," "us," or "our") operates the AI-assisted book creation platform at masterprose.com. MasterProse is the data controller responsible for your personal information collected through the Service.

For privacy inquiries, you can reach us at privacy@masterprose.com.

2 Information We Collect

2.1 Information You Provide Directly

CategoryExamplesWhen Collected
Account Information Email address, password (hashed), display name, pen name Registration / sign-in
Google Sign-In Data Google account email, name, profile photo URL If you choose Google authentication
Payment Information Billing name, last 4 digits of card (stored by Stripe, not us), billing country Subscription purchase
User Inputs & Projects Book titles, plot summaries, character descriptions, genre selections, all text inputs to AI, your editing of AI-generated prose While using the writing tool
Support Communications Email content, issue descriptions, attachments When you contact support
Community Content Published works, author name, genre tags, content ratings When you publish to Community

2.2 Information Collected Automatically

CategoryExamplesPurpose
Usage Data Chapters generated, illustrations created, words generated, export attempts, features used Usage limit enforcement, subscription management, Creator Credit calculations
Log Data IP address, browser type, operating system, pages visited, timestamps, referring URL Security, debugging, service improvement
Device Information Browser version, screen resolution, language settings Technical compatibility
Firebase Analytics Session duration, feature interaction events (if analytics are enabled) Understanding how users engage with the platform

2.3 Information from Third Parties

We receive limited information from our service providers in the normal course of operating the Service:

3 How We Use Your Information

We use your information only for the purposes described below. We do not sell your personal information to third parties.

PurposeInformation UsedLawful Basis (GDPR)
Providing and operating the Service Account info, user inputs, usage data Contract performance
Processing payments and managing subscriptions Account info, payment info (via Stripe) Contract performance
Enforcing free-tier limits and subscription access Usage data, subscription status Contract performance / Legitimate interest
Generating AI content based on your inputs User inputs (sent to Anthropic API) Contract performance
Operating the Community platform Published works, read-event data Contract performance / Legitimate interest
Calculating Creator Credits Read-event data, account info Contract performance
Communicating with you (account, billing, support) Email address, support messages Contract performance / Legitimate interest
Improving the Service Aggregated usage data, log data Legitimate interest
Security and fraud prevention Log data, IP address, account activity Legitimate interest / Legal obligation
Legal compliance As required Legal obligation
Marketing (only with your consent) Email address Consent
We do not sell your personal information. MasterProse does not sell, rent, or trade your personal information to third-party advertisers or data brokers. We do not use your creative content to train AI models.

4 How We Share Your Information

We share your information only as described below:

4.1 Service Providers

We share information with trusted third-party service providers who help us operate the Service, under contracts that require them to protect your information and use it only for the purposes we specify:

4.2 Community Platform

If you publish a work to the MasterProse Community, that work — including your chosen author name, book title, cover art, and story content — will be visible to other MasterProse users and, potentially, public Community readers. Please only publish content you are comfortable sharing publicly.

4.3 Legal Requirements

We may disclose your information if required to do so by law or in response to valid legal process (such as a subpoena or court order), or if we believe in good faith that disclosure is necessary to protect our rights, protect your safety or the safety of others, investigate fraud, or respond to a government request.

4.4 Business Transfers

If MasterProse is acquired by or merged with another company, your information may be transferred as part of that transaction. We will provide notice before your information becomes subject to a different privacy policy.

4.5 With Your Consent

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

No Advertising Networks MasterProse does not share your information with advertising networks, and we do not display third-party advertisements in the Service.

5 Cookies & Tracking

5.1 What We Use

MasterProse uses the following types of browser storage:

We do not currently use third-party advertising cookies, cross-site tracking cookies, or behavioral targeting technologies.

5.2 Analytics

We may use Firebase Analytics (Google) to understand how users interact with the Service. Firebase Analytics collects anonymized usage events. You can opt out of Firebase Analytics data collection through your browser's "Do Not Track" settings or by using browser privacy extensions. This does not affect core Service functionality.

5.3 Managing Cookies

You can manage or delete browser cookies through your browser settings. Note that clearing authentication cookies will sign you out of the Service and clearing IndexedDB will remove locally cached project data (your cloud-saved data in Firestore will not be affected).

6 AI Processing & Your Content

6.1 How Your Inputs Are Used

When you use MasterProse to generate prose, illustrations, or translations, your User Inputs (plot descriptions, character details, genre selections, etc.) are transmitted to third-party AI APIs (currently Anthropic for prose, image generation services for illustrations) to produce AI-Generated Content. This is necessary for the Service to function.

6.2 We Do Not Train On Your Content

MasterProse does not use your User Inputs, User Content, or AI-Generated Content to train or fine-tune AI models, and we do not provide your creative content to AI providers for training purposes. Our agreements with Anthropic cover API use only. Anthropic's API, by default policy, does not use API inputs to train Anthropic's models. Please review Anthropic's privacy policy at anthropic.com for their current data practices.

6.3 Storage of Generated Content

Your completed book projects — including AI-generated prose and illustrations — are stored in your private Firestore account space, accessible only to you (and to us as necessary to operate the Service). Projects are not publicly accessible unless you choose to publish to the Community.

7 Community & Public Content

If you publish a work to the MasterProse Community, you should be aware that:

Exercise care about any personal information you choose to include in the narrative content of published works, as that content becomes publicly accessible.

8 Data Retention

We retain your personal information for as long as your account is active or as needed to provide the Service. Specifically:

9 Security

We implement reasonable technical and organizational measures to protect your personal information against unauthorized access, alteration, disclosure, or destruction. These measures include:

No method of transmission over the Internet or electronic storage is 100% secure. While we strive to protect your information using commercially reasonable means, we cannot guarantee absolute security. In the event of a data breach affecting your rights and freedoms, we will notify you and applicable regulators as required by law.

10 Children's Privacy

The Service is not directed to children under the age of 13, and we do not knowingly collect personal information from children under 13 without verifiable parental consent. Users between 13 and 17 may use the Service only with verifiable parental or guardian consent.

If we become aware that we have collected personal information from a child under 13 without proper consent, we will take steps to delete that information promptly. If you believe we have inadvertently collected information from a child under 13, please contact us at privacy@masterprose.com.

11 Your Rights & Choices

Depending on where you live, you may have certain rights regarding your personal information. Regardless of your location, we offer the following choices to all users:

Access

Request a copy of the personal information we hold about you.

Correction

Update or correct inaccurate personal information through your account settings or by contacting us.

Deletion

Request deletion of your account and personal data. We will honor this within 30 days, subject to legal retention requirements.

Data Portability

Export your book projects at any time using the Service's built-in export functionality.

Marketing Opt-Out

Unsubscribe from promotional emails at any time using the unsubscribe link in any email, or by contacting us. Transactional emails (receipts, security alerts) cannot be opted out of while your account is active.

Account Closure

Close your account at any time by contacting support@masterprose.com. This will also cancel any active subscription at the end of the current billing period.

To exercise any of these rights, contact us at privacy@masterprose.com. We will respond within 30 days (or shorter where required by law). We may need to verify your identity before processing certain requests.

12 California Privacy Rights (CCPA / CPRA)

If you are a California resident, the California Consumer Privacy Act (CCPA) as amended by the California Privacy Rights Act (CPRA) provides you with additional rights regarding your personal information.

12.1 Categories of Personal Information Collected

In the past 12 months, we have collected the following categories of personal information as defined by CCPA: Identifiers (email, IP address); Commercial information (subscription records, payment history); Internet or network activity (log data, usage data); Geolocation data (general location from IP address); Inferences drawn from other information (subscription tier, feature preferences).

12.2 Your California Rights

12.3 How to Submit a California Rights Request

Email: privacy@masterprose.com with subject line "California Privacy Request." You may also contact the California Department of Consumer Affairs, Consumer Assistance Unit, 1625 North Market Blvd., Suite N 112, Sacramento, CA 95834, telephone (800) 952-5210.

13 EU/EEA & UK Privacy Rights (GDPR / UK GDPR)

If you are located in the European Union, European Economic Area, or United Kingdom, you have rights under the General Data Protection Regulation (GDPR) or UK GDPR, including:

13.1 Lawful Basis for Processing

We process your personal data under the following lawful bases: (a) Contract performance — processing necessary to provide the Service you subscribed to; (b) Legitimate interests — security monitoring, fraud prevention, service improvement; (c) Legal obligation — tax and financial record keeping; (d) Consent — marketing communications (you may withdraw consent at any time).

13.2 Data Protection Contact

For GDPR-related requests or to lodge a complaint: privacy@masterprose.com. You also have the right to lodge a complaint with your local supervisory authority (e.g., the ICO in the UK, or your national data protection authority in the EU).

14 International Data Transfers

MasterProse is based in the United States. If you access the Service from outside the U.S., your information will be transferred to and processed in the United States, which may have different data protection laws than your country.

For transfers from the EU/EEA or UK to the U.S., we rely on appropriate safeguards as required by GDPR, including: Standard Contractual Clauses (SCCs) incorporated in our agreements with service providers such as Google and Stripe who participate in international data transfer frameworks; and the UK International Data Transfer Addendum where applicable.

By using the Service from outside the U.S., you acknowledge and consent to the transfer of your information to the U.S. as described in this Policy.

15 Third-Party Links

The Service may contain links to third-party websites or services (such as KDP Publishing guides or payment portals). These third-party sites have their own privacy policies, and we are not responsible for their content or practices. We encourage you to review the privacy policies of any third-party sites you visit.

16 Changes to This Policy

We may update this Privacy Policy from time to time to reflect changes in our practices, technology, legal requirements, or other factors. When we make material changes, we will notify you by email or by posting a prominent notice on the Service at least 14 days before the change takes effect. The "Effective Date" at the top of this Policy reflects when it was last updated.

Your continued use of the Service after the updated Policy takes effect constitutes your acceptance of the changes. If you do not agree to the updated Policy, you should stop using the Service and may close your account.

17 Contact Us

If you have any questions, concerns, or requests regarding this Privacy Policy or how we handle your personal information, please contact us:

MasterProse — Privacy Team
Email: privacy@masterprose.com
General Support: support@masterprose.com
Website: masterprose.com

We aim to respond to all privacy inquiries within 30 days.