Privacy Policy for SankeyStone

Last Updated: September 1, 2025

1. Introduction

This Privacy Policy describes how SankeyStone ("we," "our," or "the extension") handles information when you use our Chrome browser extension. We are committed to protecting your privacy and being transparent about our data practices.

2. Information We Collect and Store

2.1 Local Storage Only

SankeyStone stores the following information locally on your device only using Chrome's local storage APIs:

• API Keys: Third-party service API keys (e.g., OpenAI, Anthropic) that you provide
• User Preferences: Your settings and configuration preferences
• Extension State: Information needed for the extension to function properly

2.2 No Server-Side Data Collection

We do NOT collect, transmit, store, or process any of your data on our servers. All data remains on your local device.

3. How We Use Your Information

The locally stored information is used solely to:

• Enable the extension's core functionality
• Authenticate with third-party APIs using your provided keys
• Remember your preferences and settings
• Provide a consistent user experience

4. Third-Party Services

When you use SankeyStone, the extension may communicate directly with third-party services using your API keys:

• AI Services: OpenAI, Anthropic, or other AI providers you configure
• Data Handling: Any data sent to these services is subject to their respective privacy policies
• Direct Communication: The extension communicates directly from your browser to these services

5. Data Security

We implement the following security measures:

• Local Storage: All sensitive data is stored locally using Chrome's secure storage APIs
• No Transmission: Your API keys and personal data are never transmitted to our servers
• Encryption: Chrome's built-in storage encryption protects your locally stored data

6. Data Retention and Deletion

• Retention: Data is retained locally until you manually delete it or uninstall the extension
• Deletion: You can delete your data at any time through the extension's settings
• Uninstallation: All locally stored data is automatically removed when you uninstall the extension

7. Permissions

SankeyStone requests the following Chrome permissions:

• Storage: To store your API keys and preferences locally
• Active Tab: To interact with the current web page when you use the extension
• Host Permissions: To communicate with third-party AI services

8. Children's Privacy

SankeyStone is not intended for use by children under 13. We do not knowingly collect information from children under 13.

9. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. When we do, we will:

• Update the "Last Updated" date at the top of this policy
• Notify users of significant changes through the extension or our GitHub repository

10. Your Rights

Since all data is stored locally on your device, you have complete control over your information:

• Access: You can view all stored data through the extension's settings
• Modification: You can modify or update your data at any time
• Deletion: You can delete specific data or all data through the extension settings
• Portability: Your data is stored in standard formats on your device

11. Open Source

SankeyStone is open source software. You can:

• Review our source code on GitHub: https://github.com/Kurlan/SankeyStone
• Verify our privacy practices by examining the code
• Report issues or contribute improvements

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This privacy policy is effective as of the date listed above and applies to all users of the SankeyStone Chrome extension.