Sub-processors
The complete list of companies that process data as part of The Book Companion, what each one does, and what data it touches. Referenced by the Data Processing Agreement. Changes are announced by email to every author with a live Book Companion before any new sub-processor handles reader data.
Vercel Inc.
USA (functions run in the EU, Frankfurt region)Application hosting and content delivery. Also transient storage of the uploaded book file during processing (deleted automatically when processing completes).
Data involved: All application traffic; the uploaded file during processing only.
Neon Inc.
EU (Frankfurt region)Postgres databases. Each Book Companion gets its own isolated database.
Data involved: Book text, reader accounts, and conversations.
Anthropic PBC
USAThe Claude API generates the AI answers. Anthropic does not train models on API data.
Data involved: Book text and reader questions, sent per request to generate answers.
Resend Inc.
USATransactional email (sign-in links and codes, service notices).
Data involved: Email addresses and sign-in codes only. Never book content, never conversation content.
Where a sub-processor is outside the EU, transfers rest on an adequacy decision or Standard Contractual Clauses in that sub-processor's own data processing agreement.