Privacy Policy

Kech is a personal audiobook generator and a product of Lynna Labs Ltd, a company registered in England and Wales (company number 17168299), whose registered office is at 71-75 Shelton Street, Covent Garden, London WC2H 9JQ, United Kingdom (https://www.lynnalabs.com). In this Privacy Policy, "we", "us", and "our" refer to Lynna Labs Ltd, and "you" refers to the account holder using Kech.

We are the controller of your personal data under the UK General Data Protection Regulation and the Data Protection Act 2018, registered with the Information Commissioner's Office under reference ZC270880.

Kech is single-user scoped. Every book, chapter, and audio file belongs to one account. There is no sharing, no organizations, and no workspaces.

• To authenticate you and keep you signed in.
• To extract text from your PDF, generate a narration script for each chapter, synthesize audio, and make it available in your library.
• To save and restore your playback position and chapter navigation.
• To operate, secure, debug, and improve the service.
• To take payment, keep accounting records, and meet our legal obligations.
• To give support: an administrator may view your library as you see it to investigate a problem you report or a failure in processing. Every such view is recorded in an audit log.
• We do not sell your data.
• We do not use your content to train our own models, and we do not grant third parties the right to train their models on it (see Section 6).

• Contract: Most processing is needed to provide the service you signed up for: your account, turning your PDFs into audiobooks, playback, and purchases.
• Legitimate interests: Keeping the service secure, preventing abuse, tracking errors, and giving support.
• Legal obligation: Keeping payment and accounting records that tax law requires.

You must only upload PDFs you have the right to adapt into audio, as set out in our Terms of Service. Kech creates a private, personal narration for your own listening. It is not a tool for redistributing or publishing copyrighted works. You are responsible for the material you upload.

• Database: Account records, book and chapter metadata, narration scripts, glossary, and playback progress are stored in a managed PostgreSQL database (Neon).
• Object storage: Source PDFs and generated chapter audio are stored in Amazon S3. Uploads go straight from your browser to S3 using short-lived presigned links, and audio is delivered to your player through Amazon CloudFront using signed links that expire after a few hours.
• Hosting: The application and its background processing run on Vercel.

Some of these providers process data outside the UK, mainly in the United States. Where they do, the transfer is covered by the UK's adequacy regulations (including the UK-US data bridge) or by the standard contractual clauses and UK addendum in each provider's data processing terms.

Kech relies on the following services to operate:

• Google: Provides sign-in. Google receives the information necessary to authenticate you and returns your basic profile. Google's privacy policy applies to that exchange.
• Google Gemini (via the Vercel AI SDK): Where configured as the script model, text extracted from your PDF is sent to the Gemini API to generate the narration script for each chapter. Where configured as the speech provider, the narration script is also sent to the Gemini API to synthesize speech. Google's API data-use terms apply; API content is not used to train Google's models.
• OpenAI (via the Vercel AI SDK): Where configured, used for speech synthesis, and optionally for narration scripts in place of Gemini. Narration scripts — and, where configured, extracted PDF text — are sent to the OpenAI API. OpenAI's API terms apply; API content is not used to train OpenAI's models.
• ElevenLabs: An alternative speech provider. Where configured, narration scripts are sent to the ElevenLabs API to synthesize speech. ElevenLabs' API terms apply.
• Stripe: Handles payment where Kech is configured to charge. Stripe receives your email address and your payment details directly; we never receive or store card details. Stripe's privacy policy applies.
• Neon: Hosts the application database.
• Amazon Web Services (S3 and CloudFront): Stores uploaded PDFs and generated audio, and delivers audio to your player.
• Vercel: Hosts the application and runs the background job queue that processes your books.
• Upstash: Where configured, caches short-lived playback links and rate-limit counters. It holds no PDF text, no narration, and no audio.
• Sentry: Receives error reports so we can find and fix problems. Reports carry internal identifiers, not your name, email address, or book text.

Your account data is retained for as long as your account is open. Book data — the source PDF, extracted text, script, glossary, and audio — is retained until you delete the book or close your account.

Deleting a book removes its database records and its files straight away; stored copies kept for recovery are removed within 7 days. To delete your account and all data associated with it, contact us at the address below and we will do so within 30 days; residual copies in encrypted database backups are purged on the normal backup rotation.

Warning and error logs are deleted after 90 days. Records of the processing each book used are kept for our accounts and are no longer linked to you once your account is deleted. Stripe keeps its own payment records for as long as the law requires.

Kech uses one cookie and a few kinds of browser storage, all needed for the service to work, so we do not ask for consent to them:

• Session cookie: A secure, httpOnly cookie that authenticates your session. It is cleared when you sign out.
• Offline audio: If you choose to keep chapters on your device, their audio is stored in your browser's storage (IndexedDB) so they play without downloading again. You can remove it from a book's chapter list, or by clearing your browser's site data.
• Player state: The book and position you are listening to are kept in this browser tab (sessionStorage), so the player survives a page refresh. It is cleared when the tab closes.
• Theme: Your light or dark mode choice is remembered in your browser (localStorage).

We do not use advertising cookies, cross-site tracking pixels, or third-party analytics.

Traffic is served over HTTPS. Every query and mutation is scoped to the signed-in account, so one account cannot read or modify another account's books, chapters, or playback data. File access goes through short-lived presigned URLs rather than public links. No system is perfectly secure, but we take reasonable measures to protect your data.

Under UK data protection law, you may have the right to access, correct, export, or delete your personal data. You can view your name, email, and sign-in method on the Account page, and delete books yourself from your library at any time. For any other request, contact us and we will respond within one month.

If you are unhappy with how we handle your data, please contact us first. You can also complain to the UK Information Commissioner's Office (ico.org.uk).

Kech is not directed to children and is not intended for use by anyone under 13.

We may update this Privacy Policy as the service evolves. Material changes will be communicated in the app or by email to the address on your account. The date below reflects when the policy was last revised.

Questions about this policy or your data can be sent to hello@lynnalabs.com, or by post to Lynna Labs Ltd, 71-75 Shelton Street, Covent Garden, London WC2H 9JQ, United Kingdom.