Last updated: August 2026
LayerGlyph is a local-first reading-memory tool. Your Kindle highlights, notes, book reviews/reflections, reading status, tags, bookmarks, and other private reading content are stored primarily in the Chrome extension's local IndexedDB on your device. A LayerGlyph account is not required for the core product or for the Notion connection described below.
Notion is optional and does not require a LayerGlyph account. When you choose to connect Notion, LayerGlyph opens Notion's authorization flow. LayerGlyph's server-side relay handles only the OAuth/token control-plane work needed to protect the Notion client secret; it does not receive your books, highlights, notes, reviews, or other reading payloads.
After you choose a Notion destination and start a sync, the Chrome extension sends the selected LayerGlyph book/highlight content directly to Notion's API. The current integration is one-way from LayerGlyph to Notion. Optional automatic Notion sync is a separate setting and runs only while Chrome can execute the extension.
Disconnecting removes the local Notion connection state and attempts to revoke the connection. It does not automatically delete pages already created in your Notion workspace.
During Kindle import, after the in-product disclosure is acknowledged through the import action, LayerGlyph may contribute a minimal book-catalog record to LayerGlyph: marketplace/locale, ASIN, visible title, visible author, a validated cover URL when available, source, and schema/disclosure versions. Highlight text, notes, reviews/reflections, tags, reading status, Amazon credentials, user identifiers, and backup contents are not included in that catalog contribution.
When you use book search or cover/metadata lookup, bounded bibliographic fields such as a title, author, ISBN, or provider identifier may be sent to the selected metadata provider (for example Open Library, NDL Search, or openBD). Private highlight/note/review text is not sent to those providers.
Recommendation-signal sharing is separate from Notion, catalog contribution, backup, and authentication. Its scopes are off by default and require explicit opt-in. When an enabled release and an enabled scope allow transmission, LayerGlyph sends only allow-listed, minimized derived signals such as bounded reading-status or book/topic identifiers. Raw highlight text, note text, private reflections/reviews, private tags, and raw search text are excluded.
LayerGlyph may use limited product analytics only where the relevant analytics gate is enabled. Reading-content text is not sent to analytics, sold to third parties, shared with advertisers, or used to train AI models.
The current core product and Notion integration do not require a LayerGlyph account. Any future or separately offered account/cloud feature is independent from local reading storage and requires its own user action. Cloud backup and multi-device content sync are not enabled as part of the current local-first core release.
The production Store package does not request broad all-site access. Host access is limited to the Kindle Notebook, LayerGlyph's own production web origins, Notion's API, and bounded book-metadata/cover providers required by user-facing book lookup features.
Depending on the feature you explicitly use, LayerGlyph may communicate with Amazon Kindle, Notion, Vercel-hosted LayerGlyph services, Supabase-hosted bounded service endpoints, Open Library/Internet Archive, NDL Search, openBD, and limited analytics infrastructure. Each path is feature-scoped; authorization for one destination does not grant consent for another.
LayerGlyph's use and transfer of information received from Chrome APIs complies with the Chrome Web Store User Data Policy, including the Limited Use requirements. Chrome user data is used only to provide or improve the user-facing LayerGlyph features described here and is not used for personalized advertising, creditworthiness, or sale to data brokers.
You can delete local books, highlights, reviews/reflections, bookmarks, and other local records from LayerGlyph. Removing the extension or clearing its site data may remove locally stored data, so use the JSON backup before doing so when you need a recovery copy. Data already exported to a third-party destination such as Notion is governed by that destination and must be deleted there as needed.
Questions about this policy? Email yutaro.private@gmail.com.