Privacy Policy

Last updated: November 30, 2024

This Privacy Policy explains how Diff ("we", "us", or "our") handles your information when you use our desktop note-taking application. We built Diff with privacy as a core principle — your data stays on your device.

Contact: mikolajkacki98@gmail.com
Jurisdiction: London, United Kingdom

1. The Short Version

  • Your notes never leave your device unless you explicitly send them to an AI provider

  • Analytics are on by default but only track anonymous feature usage — not your content

  • You bring your own API keys for AI features — we never see your content or keys

  • We don't have servers that store your notes, files, or personal data

2. What Stays on Your Device (We Never See This)

All of the following is processed and stored locally on your device only:

Data Where It's Stored Notes, text, and formatting Local database Attachments and media Local filesystem Search queries and history Local database AI-generated summaries Local database Semantic embeddings Local database App settings and preferences Local config files OAuth tokens (GitHub, Linear, Slack) macOS Keychain* AI provider API keys macOS Keychain

We have no access to this data. It never touches our servers.

*Slack OAuth requires a one-time server handshake — see Section 4.2 for details. The token is not stored on our server.

3. What We Collect

3.1 Analytics (Enabled by Default)

We use PostHog (EU-hosted, GDPR-compliant) to collect anonymous usage data:

What we collect:

  • Randomly generated device ID (not linked to you personally)

  • License key (as anonymous identifier, when applicable)

  • Feature usage events (e.g., "note created", "search performed", "AI enhancement used")

What we DO NOT collect:

  • Note content or text

  • Search queries or keywords

  • File names or attachments

  • Your name, email, or IP address

  • Anything that could identify you

Opt-out: Settings → General → Analytics → Toggle Off

3.2 License Purchases

When you purchase a license through Lemon Squeezy:

  • Your payment is processed entirely by Lemon Squeezy

  • We receive only your license key and purchase confirmation

  • We never see your payment details, billing address, or personal information

See: Lemon Squeezy Privacy Policy

4. Third-Party Services

4.1 AI Providers (Direct Connection)

When you use AI features (semantic search, summaries, enhancements):

  1. You provide your own API key — stored in your system keychain

  2. Your device connects directly to your chosen AI provider (OpenAI, Anthropic, Voyage AI, etc.)

  3. We never see or intercept your content or API communications

Your responsibility: Review your AI provider's privacy policy:

4.2 Integrations

GitHub and Linear:

  • OAuth authentication happens directly between your device and the provider

  • Access tokens are stored in your system keychain

  • Your device fetches data directly from their APIs

Slack:

  • OAuth authentication is routed through our server (hosted on Railway) to complete the handshake

  • We do not store your Slack token — it is returned to your device and stored in your system keychain

  • After authentication, your device communicates directly with Slack's API

For all integrations, we never store or have ongoing access to your tokens or data.

4.3 Analytics Provider

Provider Purpose Location Policy PostHog Anonymous usage analytics EU posthog.com/privacy

4.4 Payment Provider

Provider Purpose Policy Lemon Squeezy License purchases lemonsqueezy.com/privacy

5. Data Security

Local Security

  • Data stored in local database on your device

  • Sensitive credentials stored in macOS Keychain

  • Backend server binds to 127.0.0.1 (localhost only — no remote access)

Network Security

  • All third-party API calls use HTTPS encryption

  • No cloud sync — your data doesn't traverse our infrastructure

Your Responsibility

  • Secure your device (password, disk encryption, physical access)

  • Protect your API keys and OAuth tokens

  • Maintain backups of your local data

6. Data Retention

Local Data

Your data remains on your device until you delete it. Uninstalling Diff does not automatically remove your database.

To fully delete your data:

  • ~/Library/Application Support/Diff/

Analytics Data

PostHog retains anonymised data per their retention policy. Contact us to request deletion.

7. Your Rights (GDPR)

You have the right to:

Right How to Exercise Access Request what analytics data we hold (minimal, anonymised) Deletion Request deletion of analytics data Opt-out Disable analytics in Settings Portability Export your local database Objection Object to analytics processing

Contact: mikolajkacki98@gmail.com

8. What We Don't Do

  • Sell your data

  • Share your data for advertising

  • Train AI models on your content

  • Store your notes on our servers

  • Track you across websites

  • Collect personal identifiers

9. Children

Diff is not intended for children under 13. We do not knowingly collect information from children under 13.

10. Changes

We may update this policy. Material changes will be announced in the app. Continued use after changes constitutes acceptance.

11. Contact

Privacy inquiries: mikolajkacki98@gmail.com
Website: getdiff.dev

Version 1.0 — November 30, 2024

Privacy Policy

Privacy Policy