Privacy Policy

Effective date: 24 March 2026

The short version: Crux stores your decisions on your device. Your conversation text is sent to Google's Gemini AI to generate responses. We do not serve ads, or sell your data, and data collection is anonymous and solely for the purpose of improving Crux. If you sign in with Apple, we store your name and email only for account management.

Who We Are

Crux is developed by Matthew Chrisp. Crux is a decision-coaching app that helps you think through complex life decisions using AI-guided conversation. This policy explains exactly what data the app handles and where it goes.

Data Stored on Your Device

All of your decision data is stored locally on your device using Apple's SwiftData framework. This includes:

• Your decisions — the title, current phase, and final outcome of each decision session
• Conversation history — every message you send and every AI response, stored so you can resume and review past sessions
• Decision tree structure — the options, sub-options, upsides, downsides, and impact ratings you develop during each session
• Session counters — the number of free sessions used and paid sessions available, stored in UserDefaults

This data lives on your device and is not uploaded to our servers. If you delete the app, this data is permanently erased.

Data Sent to Google's Gemini AI

Crux uses Google's Gemini AI (via the Firebase AI SDK) to power the decision-coaching conversation. When you send a message, the following is transmitted to Google's servers over an encrypted HTTPS connection:

• Your conversation history — all messages in the current decision session, so the AI has context to provide meaningful responses
• Your decision tree — the options, sub-options, and their relationships, so the AI can reference them accurately
• Your impact ratings — when you adjust the importance or severity ratings on options, these adjustments are shared so the AI can acknowledge where your assessment differs from its initial read
• System instructions — the coaching methodology that guides the AI's behaviour (these do not contain your personal information)

The content of your decisions — what you're weighing, why it matters, how you feel about it — is transmitted to Google as part of this process. Google's use of this data is governed by Google Cloud's Terms of Service and the Firebase Terms of Service.

What is not sent to the AI: your name, email address, Apple ID, device identifiers, or any data from previous decision sessions. Each decision session's data is self-contained.

Sign in with Apple

Crux offers optional Sign in with Apple for account management. If you choose to sign in, we request:

• Your name — provided by Apple on your first sign-in only
• Your email address — you can choose to share your real email or use Apple's private relay address

This information is stored in Firebase Authentication, a Google service, solely for account identification. We do not use it for marketing, share it with third parties, or combine it with your decision data. Apple only shares your name and email on your first sign-in; subsequent logins do not retransmit this information.

If you opt in to product update emails via the toggle in your Profile, we store your email address locally on your device for future use. We do not currently send marketing emails, but by opting in you consent to receiving occasional product updates at the email associated with your Apple ID. You can opt out at any time from the Profile screen.

Sign in is not required to use Crux. You can use the app without creating an account.

In-App Purchases

Crux offers consumable in-app purchases (decision sessions) through Apple's StoreKit framework. All payment processing is handled entirely by Apple. We do not receive, store, or have access to your payment details, credit card number, or Apple ID password. We only know whether a purchase was completed successfully so we can credit your account with a session.

Analytics and Tracking

Crux collects anonymous usage analytics to improve the app. This includes which stages of the decision process are completed, how long each stage takes, the general category of the decision (e.g. Career, Relationship — classified by the AI without sharing your actual decision content), and engagement events like viewing option cards or sharing a decision. No conversation text, decision details, branch names, or personally identifiable information is included in analytics. Analytics data is processed by Firebase Analytics and is not linked to your identity. You can opt out of analytics at any time in the Profile settings.

Data We Do Not Collect

Crux does not access or collect:

• Location data
• Contacts or address book
• Photos or camera
• Health or fitness data
• Financial information (beyond purchase receipts handled by Apple)
• Browsing history
• Device sensor data

Data Retention

On your device: Your decision data is stored locally for as long as you keep the app installed. Deleting the app permanently removes all local data, including decisions, conversation history, and session counters.

Firebase Authentication: Your account data (name and email) is retained until you delete your account. You can delete your account from the Profile screen within the app, which removes your Firebase authentication record and all local data.

Gemini AI: Conversation data sent to Google's Gemini API is subject to Google's data retention policies. Crux does not control how long Google retains API request data. Refer to Google Cloud's data policies for details.

Account Deletion

You can delete your account at any time from the Profile screen in the app. Account deletion:

• Permanently deletes all decisions, conversation history, and decision trees from your device
• Resets your session counters
• Removes your Firebase authentication account (name and email)

This action cannot be undone.

Children's Privacy

Crux is not directed at children under 17. We do not knowingly collect personal information from children. If you believe a child has used the app to process personal information, please contact us and we will take steps to address it.

Security

All data transmitted between Crux and external services (Firebase Authentication, Gemini AI, Apple StoreKit) is encrypted in transit using HTTPS/TLS. Sign in with Apple uses cryptographic nonce verification to prevent replay attacks. Local data is stored using Apple's SwiftData framework with the default device-level encryption provided by iOS.

International Data Transfers

Your conversation data is processed by Google's Gemini AI and Firebase services, which may operate on servers located outside your country of residence. By using Crux, you acknowledge that your data may be transferred to and processed in countries other than your own.

Changes to This Policy

If we make material changes to this privacy policy, we will update the effective date at the top of this page. We encourage you to review this policy periodically.