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FusionMD — Privacy Policy

DataIsland Software LLC  ·  Last updated: 20 May 2026

FusionMD is a Markdown document studio for macOS. This policy explains what FusionMD accesses, what leaves your device, and what is stored locally.

Summary

FusionMD does not collect personal data. Your documents are stored locally as .fusiondoc files (plain Markdown with metadata). Document content is never sent to DataIsland. AI features are opt-in — either on-device via Apple Intelligence (nothing leaves your Mac) or via OpenRouter (with your own API key and your explicit consent). FusionMD has no server, no account, and no analytics.

Your Documents

FusionMD stores documents as .fusiondoc files on your Mac, in locations you choose. The format is plain Markdown with a small JSON metadata header — your content is always recoverable without FusionMD. Documents are never transmitted to DataIsland.

What Leaves Your Device

OpenRouter (Optional — Opt-In Only)

FusionMD can optionally use the OpenRouter API to provide AI writing assistance. This feature:

  • Is disabled by default
  • Requires you to supply your own OpenRouter API key in Settings → AI
  • Sends the active document or selected text to OpenRouter's servers when you invoke an AI action (generate, refine, summarise, etc.)
  • Is governed by OpenRouter's privacy policy

DataIsland does not receive or store any document content sent through OpenRouter. Your API key is stored only in your macOS Keychain.

Apple Intelligence (Optional — Opt-In Only)

On supported hardware (Apple Silicon Mac, macOS 26, Apple Intelligence enabled), FusionMD can use Apple Intelligence for AI writing assistance. Apple Intelligence processes everything on-device. No document content leaves your Mac via this path. Apple Intelligence is governed by Apple's privacy policy.

No Other Outbound Network Activity

When neither AI feature is enabled, FusionMD makes no outbound network connections. It is a fully offline-capable application.

What Is Stored Locally

  • Documents — stored as .fusiondoc files in user-chosen locations
  • Templates — stored as .fusiontemplate files
  • Settings and preferences — stored in UserDefaults, local only
  • OpenRouter API key (if provided) — stored in macOS Keychain
  • Recent documents list — stored in UserDefaults, local only

None of this data is synced to iCloud by FusionMD or transmitted to DataIsland. (If you store documents in an iCloud-backed folder, iCloud's own sync applies under Apple's privacy policy.)

Analysis Tools

FusionMD includes eight document analysis tools (proofreader, readability, style clarity, grammar, etc.). All analysis runs locally on your Mac using system frameworks and built-in rules. No document content is sent to any server to perform analysis.

IDML Export

IDML export generates a structured file on your Mac from your document content. The export process is local. No document content is transmitted to DataIsland or any server.

What FusionMD Does Not Do

  • Does not send document content to DataIsland or any server (except OpenRouter if enabled)
  • Does not require an account or login
  • Does not collect analytics or send crash reports to DataIsland
  • Does not share any data with third parties for advertising
  • Does not sync documents to any DataIsland cloud service

Children's Privacy

FusionMD is not directed at children under 13. We do not knowingly collect information from children.

Changes to This Policy

If we make material changes to this policy, we will update the "Last updated" date above. Continued use of FusionMD after changes constitutes acceptance of the updated policy.

Contact

Questions about this policy:
support@dataisland.com
DataIsland Software LLC

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