Privacy Policy - Substack Insights Browser Extension
Last updated: December 2, 2024

Overview
Substack Insights is a browser extension that provides analytics for Substack creators. We are committed to your privacy and operate on a privacy-first, local-only processing model.

What We Collect
Nothing. We collect zero data.

This extension:

❌ Does NOT collect personal information
❌ Does NOT track your browsing
❌ Does NOT send data to external servers
❌ Does NOT use analytics or telemetry
❌ Does NOT require an account or email address
❌ Does NOT store data remotely
How the Extension Works
Local Processing Only
All analytics processing happens entirely in your browser. When you analyze your Substack publication:

The extension accesses your Substack publication data using your existing Substack session
Data is processed locally in your browser's memory
Analytics results are displayed to you
Nothing is transmitted to external servers
Browser Storage
The extension uses your browser's local storage to:

Cache your most recent analytics results (stored locally on your device)
Remember your preferences and settings (stored locally on your device)
This data:

Never leaves your device
Can be cleared at any time through browser settings
Is only accessible to you
Substack Authentication
To fetch your publication data, the extension:

Uses your existing Substack session cookie (substack.sid)
Accesses Substack's API directly from your browser
Does NOT store or transmit your session cookie to any third party
Permissions Explanation
The extension requires these permissions:

cookies: To access your Substack session for authentication
storage: To save analytics results and preferences locally on your device
downloads: To enable exporting analytics data as CSV/ZIP files
host_permissions for *.substack.com: To fetch your publication data from Substack's API
These permissions are used only for the functionality described and never for tracking or data collection.

Third-Party Services
Substack API
The extension communicates directly with Substack's API to fetch your publication data. This communication:

Happens directly from your browser to Substack
Uses your existing Substack authentication
Is subject to Substack's Privacy Policy
No Other Third Parties
We do not use:

Analytics services (e.g., Google Analytics)
Error tracking services
Advertising networks
Social media tracking pixels
Any other third-party data collection tools
Data Export
When you export your analytics data:

Files are generated locally in your browser
Downloads are saved to your device
No data is transmitted to external servers
You have complete control over exported files
Open Source
This extension is open source. You can:

Review the complete source code
Verify our privacy claims
Audit data handling practices
Contribute to development
Source code: [Link to your repository if public]

Children's Privacy
This extension does not knowingly collect information from anyone, including children under 13.

Your Rights
You have complete control over your data:

Access: All data is stored locally on your device
Deletion: Clear browser storage to remove all extension data
Portability: Export your analytics anytime
Control: Uninstall the extension to remove all associated data
No Tracking or Profiling
We do not:

Build profiles of users
Track usage patterns
Collect behavioral data
Share data with third parties
Use cookies for tracking purposes
Security
Your data security is maintained through:

Local-only processing (no data transmission)
No server-side storage
Use of browser security features
Read-only access to Substack data
Secure communication with Substack via HTTPS
Changes to This Policy
We may update this Privacy Policy to reflect changes in the extension. Updates will be posted with a new "Last updated" date. Material changes will be communicated through the extension update notes.

Data Collection Consent
As stated in our Firefox Add-ons listing, this extension declares:

data_collection_permissions: { required: ["none"] }
This formally declares that we collect no data through Mozilla's data collection systems.

Contact
Questions about this Privacy Policy? Contact us at:

Email: [Your support email]
Website: https://substackinsights.com
Firefox Add-ons: [Link to your Firefox listing]
Legal Compliance
This extension complies with:

GDPR (General Data Protection Regulation)
CCPA (California Consumer Privacy Act)
Firefox Add-on Privacy Policies
Since we collect no personal data, there is no data to be subject to these regulations.

Summary: This extension is completely privacy-first. All processing happens locally in your browser. We collect nothing, track nothing, and transmit nothing. Your Substack data stays yours.