Privacy Policy

Effective June 11, 2026

Quillstone is a desktop application from Cove Technology, Inc. ("we", "us"). Quillstone is offline-first: your books, characters, audio, images, and settings are stored only on your Mac unless you explicitly turn on a feature that contacts an outside service. We do not run analytics, telemetry, or crash reporting, and we do not operate a server that holds your content.

What stays on your device

All manuscripts, outlines, characters, covers, generated images, narration audio, and exports.
Your data-folder location (you choose it on first run).
API keys you enter, stored encrypted on your Mac (AES-GCM, key derived from your Mac's hardware ID, file permissions 0600). Keys are not transmitted to us.
Local AI model files you download.

What leaves your device — only when you enable it

Each of these is off by default or requires you to supply a key, and is shown with a toggle in Settings:

Cloud language models (OpenAI, Anthropic): if you enter an API key and use cloud drafting/editing/fact-check, the relevant text is sent to that provider under their privacy policy. We are not a party to that data.
ElevenLabs narration (optional): if enabled, the text to be narrated is uploaded to ElevenLabs.
Web search (Brave) / online fact-check (OpenAI): when you run a search or enable per-book fact-checking, your query is sent to that provider.
Model downloads (Hugging Face / CivitAI): when you choose to download a model, the request goes to that host.
Software updates (Sparkle): the app fetches an update feed from updates.quillstone.io to check for new versions — a standard HTTPS request that includes only what your OS/network stack normally sends.
License validation: when you activate Quillstone Pro, a single request goes to our payment processor (Lemon Squeezy) to validate your license key. Only the license key and a device identifier are sent — never your book content.

We do not sell data. We do not build advertising profiles. We do not receive your book content.

Children

Quillstone is not directed to children under 13. An optional 18+ gate restricts mature content; it is off by default.

Your choices

Turn any outbound feature off in Settings.
Delete your data by removing your data folder (Settings → Maintenance shows its location).
Export or back up your library at any time (Settings → Maintenance).

Changes & contact

We will post changes here with a new effective date. Questions: support@quillstone.io.

Quillstone is made by Neural Operations, a Cove Technology, Inc. product. · Terms of Use · quillstone.io