---
title: Stack
---

## Framework

- [Next.js](https://nextjs.org/) 15 (App Router)
- [React](https://react.dev/) 19
- [TypeScript](https://www.typescriptlang.org/)

## Containerization and runtime

- [Docker](https://www.docker.com/) (linux/amd64 and linux/arm64)
- Shared entrypoint that runs DB migrations by default and can bootstrap embedded SeaweedFS before app startup

## Next.js client

- UI: [Tailwind CSS](https://tailwindcss.com), [Headless UI](https://headlessui.com), [@tailwindcss/typography](https://tailwindcss.com/docs/typography-plugin)
- Interactions: `react-dnd`, `react-dropzone`
- Authentication: [Better Auth](https://www.better-auth.com/) client SDK
- Local storage/cache: [Dexie.js](https://dexie.org/) (IndexedDB)
- Document rendering:
  - PDF: [react-pdf](https://github.com/wojtekmaj/react-pdf), [pdf.js](https://mozilla.github.io/pdf.js/)
  - EPUB: [react-reader](https://github.com/gerhardsletten/react-reader), [epubjs](https://github.com/futurepress/epub.js/)
  - Markdown/Text: [react-markdown](https://github.com/remarkjs/react-markdown), [remark-gfm](https://github.com/remarkjs/remark-gfm)
- Text preprocessing/matching: [compromise](https://github.com/spencermountain/compromise), [cmpstr](https://github.com/remsky/cmpstr)

## Next.js server

- APIs: Route Handlers for sync, blob/content access, migrations, audiobook export, TTS/Whisper proxying
- State sync: request-based today (not realtime push updates)
- Authentication: [Better Auth](https://www.better-auth.com/) server handlers/adapters
- Metadata DB: [Drizzle ORM](https://orm.drizzle.team/) with SQLite (`better-sqlite3`) by default and optional Postgres (`pg`)
  - App tables are manually maintained in Drizzle schema files
  - Auth tables are auto-generated by the [Better Auth](https://www.better-auth.com/) CLI and migrated alongside app tables via Drizzle
- Blob storage: embedded [SeaweedFS](https://github.com/seaweedfs/seaweedfs) (`weed mini`) by default, or external S3-compatible storage via AWS SDK v3
- Audio/processing pipeline: OpenAI-compatible TTS providers, [ffmpeg](https://ffmpeg.org/) for audiobook assembly, optional [whisper.cpp](https://github.com/ggerganov/whisper.cpp) for word timestamps

## Tooling and testing

- ESLint
- TypeScript
- [Playwright](https://playwright.dev/) end-to-end tests
- Drizzle migration/generation scripts
