Kindle Storyteller

Kindle Storyteller

An iOS app that uses AI to generate on-demand audiobook snippets for Kindle.

*Read the [blog post](https://blog.ryanbbrown.com/p/i-reverse-engineered-kindle-to-build) for a detailed writeup on the technical challenges and how it works.*

https://github.com/user-attachments/assets/de0f5640-5bfc-4f0e-bfa0-ee382e467fc2

0.0 Overview

0.1 Features

• On-demand audiobook generation – Generate audio for any Kindle book from your current reading position
• Multiple TTS providers – Choose between ElevenLabs and Cartesia voices
• Configurable duration – Specify how many minutes of audio to generate (1-8 at a time)
• Auto-seek playback – When resuming, audio automatically seeks to match your current Kindle position
• Bidirectional progress sync – Listening progress syncs back to Kindle in real-time
• LLM text preprocessing – Optional GPT-based cleanup of OCR text before synthesis, including custom pauses for Cartesia
• Audiobook library – Browse and replay previously generated audiobooks
• Background playback – Lock screen controls and background audio support

0.2 Context

I usually read on a Kindle Paperwhite, but when I don't have it with me I use the Kindle app on my phone. Sometimes I want to continue reading after I have to stop using my phone (e.g. I get off the subway and walk to my destination); an audiobook would be perfect for this.

However, I don't normally listen to audiobooks, so I wouldn't want to purchase the audiobook version of my book just for a few minutes of listening when I can't use my phone. Audiobooks on Kindle also only sync with the printed book when Whispersync-for-Voice is enabled. These two factors led me to build this app.

1.0 Components

• ios-app: SwiftUI client that captures Kindle session info, and drives audiobook genertion, listening, and management. See ios-app-architecture.md.
• server: Fastify backend orchestrating Kindle fetches and tex