# The Vale App

> The Vale App is a zero-configuration, browser-based documentation linter powered by Vale. It lints Markdown, AsciiDoc, MDX, and HTML with trusted rule sets from Microsoft, Red Hat, GitLab, and Elastic. No installation required—everything runs 100% in your browser for complete privacy.

## Privacy First

Great power. Complete privacy.

The Vale App is designed to protect your work:

- **100% Browser-Based**: Everything runs locally in your browser using WebAssembly
- **Zero Server Contact**: Your documents are never sent to a server
- **No Data Transmission**: Your content never leaves your device
- **Internet Only for Packages**: We only use the internet to download the linter packages you choose
- **Works Offline**: After packages are downloaded, the app works completely offline
- **Local Storage Only**: All preferences and packages are stored in your browser's IndexedDB

## Key Features

- **Zero Configuration**: Works instantly in your browser with no setup, no config files, and no installation
- **Professional Rule Sets**: Access industry-standard style guides from Microsoft, Red Hat, GitLab, and Elastic
- **Multiple Format Support**: Full support for Markdown, MDX, AsciiDoc, and HTML
- **Fast & Modern UI**: Clean interface designed specifically for technical writers and developers

## How It Works

1. Select from pre-configured professional rule packages
2. Write, paste, or upload your documentation
3. Get instant, actionable feedback with suggestions and quick fixes

## Getting Started

- [Home Page](https://thevaleapp.com/): Learn about features and see the app in action
- [Editor](https://thevaleapp.com/editor): Start linting immediately with the online editor
- [Sign Up](https://thevaleapp.com/auth/register): Create a free account to save your preferences

## Technical Details

- **Architecture**: Built with Next.js 16, React 19, and TypeScript
- **Vale Integration**: Uses Vale WASM for client-side linting
- **Package Management**: Downloads and caches Vale rule packages in browser storage
- **Format Processing**: 
  - MDX files are pre-processed with mdx2vast before linting
  - AsciiDoc files are converted to HTML with asciidoctor.js
  - Position mapping ensures errors point to correct locations in source files

## Use Cases

- **Technical Writers**: Quickly check documentation against multiple style guides
- **Developers**: Clean up README.md and contribution docs before pushing
- **Open Source Maintainers**: Provide an easy-to-use style checker for contributors
- **Documentation Teams**: Ensure consistency across product documentation

## Technology Stack

- **Frontend**: Next.js (App Router), React, TypeScript
- **Editor**: Monaco Editor with Shiki syntax highlighting
- **Linting Engine**: Vale compiled to WebAssembly
- **Authentication**: Supabase Auth with GitHub/GitLab OAuth
- **Storage**: IndexedDB for local preference and package caching

## Optional

- [Vale Official Documentation](https://vale.sh): Learn more about the Vale linter
- [GitHub Repository](https://github.com/errata-ai/vale): Vale's open-source repository
- [Supported Style Guides](https://github.com/errata-ai/packages): Browse available Vale packages