Fast Chapter: The Voice-First Desktop Studio for Drafting Books Fast

Most writing apps are optimized for typing, not thinking out loud. Fast Chapter takes the opposite direction. It is designed for people who naturally explain ideas with their voice first, then refine with text.

Fast Chapter is a local-first Electron desktop app for drafting long-form books chapter by chapter. It combines structured project scaffolding, audio capture, transcription workflows, LaTeX writing, and practical file management into one coherent workspace.

Current scope (verified as of February 24, 2026): local account management, per-book workspaces, chapter-first LaTeX scaffolding, recording and transcription organization, in-app compile and preview, and Codex-assisted write-book sessions.

The Core Problem It Solves

Book writing is rarely linear. Most authors jump between rough voice notes, structural decisions, partial chapter drafts, and cleanup work. Traditional editors often force all of this into one generic document space. That creates friction, especially when a project gets larger.

Fast Chapter addresses this by treating a book as a real project tree, not as one giant note:

• Each chapter has its own folder and .tex file.
• Voice material is separated from manuscript files but linked by naming and folder conventions.
• Compilation and preview are first-class parts of daily writing, not an afterthought.
• File operations stay inside project boundaries, which protects the workspace from accidental path escapes.

What Happens When You Create a Book

New books are scaffolded automatically with a deterministic structure. This is one of the biggest quality-of-life wins in the app because it eliminates setup overhead and keeps projects consistent from day one.

Fast Chapter creates:

• book.json
• main.tex
• cover-page.tex
• back-page.tex
• chapters/chapter-1/chapter-1.tex
• chapters/chapter-1/assets/
• recordings/
• transcriptions/

The app also keeps main.tex synchronized with chapter includes. When chapters are added, moved, or modified through project operations, the top-level manuscript structure remains aligned with the current folder state.

Voice Workflow That Stays Organized

The voice pipeline is not just a record button. It is a folder-aware workflow that keeps source material easy to locate later, which becomes critical once you have dozens of recordings.

Recordings and text outputs are organized by intent:

• recordings/initial-outline/
• recordings/chapters/chapter-N/
• recordings/miscellaneous/
• transcriptions/initial-outline/
• transcriptions/chapters/chapter-N/
• transcriptions/miscellaneous/

Inside the recording dialog, writers can:

• Capture mic audio directly in-app.
• Choose recording type (initial outline, chapter, loose note).
• Attach manual transcript text as immediate context.
• Save and continue without breaking flow.

This gives you both a human-readable paper trail and a machine-processable source set for later drafting or automation.

OpenAI Transcription Pipeline

When an OpenAI key is configured and auto-transcription is enabled, Fast Chapter queues background transcription jobs for saved audio. The implementation uses:

• POST /v1/audio/transcriptions
• Model: gpt-4o-transcribe

The Writing Bench Experience

The workspace is split into practical lanes:

• Left: project navigator with tree actions
• Center: editor and file-level writing flow
• Right: voice workflow panel with recording, transcription, and job visibility

For manuscript work, the app supports:

• Editable text files (.tex, .txt, .md, .json, .yaml, .yml).
• Audio file preview directly in the editor area.
• Save actions with optional auto-compile for LaTeX files.
• Manual compile when you want deterministic control.

The compile path targets main.tex and can use latexmk or pdflatex, with in-app PDF preview and compile log tail visibility when needed.

Project Explorer That Feels Like a Real File Tool

Fast Chapter includes more than basic file CRUD. It supports behaviors expected in serious desktop workflows:

• Create file and folder
• Rename, delete, move
• Upload files and full folders
• Drag-and-drop internal moves
• External drop upload
• Multi-select and bulk delete/move

All operations are path-safe and constrained inside the current book root. This matters for reliability and security, especially in apps that expose filesystem actions through renderer-initiated IPC.

Write Book Mode (Codex-Assisted)

The most ambitious feature in the current version is Write Book, a guided generation workflow that turns existing project context into a chapter-by-chapter writing process.

The flow is structured in stages:

1. Checklist evaluation (chapter coverage, voice material presence, seed text checks)
2. Codex environment validation
3. Session start and live log streaming
4. Sequential chapter turns
5. Final verification pass for main.tex

Important implementation detail: this runs in a scoped runtime with workspace-write sandboxing and network access disabled for the Codex thread execution context. In other words, it is designed to be inspectable and constrained, not opaque.

The app also supports prompt-template personalization for key write-book phases, so authors can keep defaults or define custom variants and switch active templates without changing code.

Local-First by Design

Fast Chapter stores user and book data locally in a configurable working directory. The app can automatically normalize selections into a dedicated FastChapterCWD location so data remains predictable and portable.

This local-first design has practical benefits:

• Your manuscript files remain normal filesystem assets.
• You can inspect, back up, and version them with your own tooling.
• You are not blocked by cloud outages to continue drafting.
• Sensitive writing material stays under your direct control.

Technology Stack

• Electron main + preload process model
• React 18 + Vite + TypeScript renderer
• Tailwind CSS and shadcn-style UI primitives
• Typed IPC contract across main, preload, and renderer boundaries
• Node.js 20+ runtime requirement

This architecture keeps the app fast to iterate while preserving desktop capabilities such as filesystem orchestration, process execution for compilers, and secure bridge APIs.

What Makes Fast Chapter Different

Fast Chapter is not trying to be a universal writing platform. Its value comes from focus:

• Book-length workflows, not generic note-taking.
• Voice-first capture with structured outputs.
• LaTeX-native project structure from the beginning.
• Transparent operational flows that are inspectable by the writer.
• Practical developer-grade features for file operations and automation.

That combination is rare. Most tools do one or two of these things well. Fast Chapter brings them together in one desktop process.

Get Started

GitHub: https://github.com/maestromaximo/FastChapter

Releases: https://github.com/maestromaximo/FastChapter/releases

Desktop build workflow: https://github.com/maestromaximo/FastChapter/actions/workflows/build-desktop.yml

npm install
npm run dev

If your best ideas come out faster when you speak them first, Fast Chapter is built for exactly that workflow.