docs: rewrite README with comprehensive feature documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: hlsitechio

README.md

@@ -1,6 +1,6 @@
 # T3 Code
 
-T3 Code is a minimal web GUI for coding agents. Currently Codex-first, with Claude Code support coming soon.
+T3 Code is a modern web GUI for coding agents. Currently Codex-first, with Claude Code support coming soon.
 
 ## How to use
 
@@ -11,13 +11,99 @@ T3 Code is a minimal web GUI for coding agents. Currently Codex-first, with Clau
 npx t3
 ```
 
-You can also just install the desktop app. It's cooler.
+You can also install the desktop app for the full experience.
 
 Install the [desktop app from the Releases page](https://github.com/pingdotgg/t3code/releases)
 
+## Features
+
+### Integrated Terminal
+- GPU-accelerated rendering via WebGL (xterm.js + `@xterm/addon-webgl`)
+- Optimized I/O with debounced input/output buffering
+- Per-thread terminal sessions with persistent history
+- Fallback to DOM renderer when WebGL is unavailable
+
+### Browser Integration (Desktop)
+- Built-in browser view powered by Chrome DevTools Protocol (CDP)
+- Navigate, observe, interact, and extract content from web pages
+- Element observation with attribute, label, and text extraction
+- Screenshot capture and action execution (click, type, scroll)
+- Side-by-side or stacked layout with the chat view
+
+### Canvas (React Code Preview)
+- Live React component preview with Babel JSX transform
+- Thread-level canvas state with file management (`App.jsx`, `styles.css`, `canvas.md`)
+- Device preview modes: Desktop, Tablet, Mobile
+- Agent-driven streaming updates to canvas files
+
+### Lab Workspace
+- Experimental workspace surfaces for new layouts and interactions
+- Browser + chat side-by-side (responsive stacking on smaller screens)
+- Thread-specific lab instances
+
+### Document Upload
+- Attach documents to chat threads (`.txt`, `.md`, `.pdf`, `.docx`)
+- Up to 16 documents per thread, 8 MB per file
+- Automatic text extraction from PDFs and Word documents
+- Document context injected into agent prompts (32K char limit)
+
+### Code Formatting
+- Automatic Prettier formatting for code blocks in chat
+- Supports JavaScript, TypeScript, HTML, CSS, Markdown, YAML, and more
+- 7 Prettier plugins with graceful fallback
+
+### IDE Integrations
+- Open projects directly in your editor of choice:
+  - **Cursor** — `cursor`
+  - **VS Code** — `code`
+  - **Windsurf** — `windsurf`
+  - **OpenCode** — `opencode`
+  - **Zed** — `zed`
+  - **File Manager** — system default
+
+### GitHub Integration
+- OAuth Device Flow authentication (RFC 8628) — no PAT required
+- GitHub CLI (`gh`) token support
+- Personal Access Token manual entry
+- Configurable GitHub actions automation, PR auto-merge, and security workflows
+
+### MCP Server Infrastructure
+- App Operator MCP server for project context, canvas mutations, and action execution
+- Lab Browser MCP server for browser observation, actions, and screenshot capture
+- Standard Model Context Protocol for agent tool integration
+
+### Project Management
+- Multi-project sidebar with favorites and thread previews
+- Thread status tracking (Working, Completed, Pending Approval)
+- Project onboarding with branch, worktree, and environment mode options
+- Folder picker integration for adding new projects
+
+### Settings
+- 8 configurable sections: Appearance, Codex, Canvas, Models, GitHub, Responses, Keybindings, Safety
+- Searchable settings with section navigation
+- Keyboard shortcuts editor
+- Model and reasoning effort selection
+- Service tier configuration (Auto/Fast/Flex)
+
+### Provider Health
+- Startup-time Codex CLI health checks (version + auth probes)
+- Minimum version enforcement (>=0.37.0)
+- Status indicators: Ready, Limited, Attention
+
+## Architecture
+
+T3 Code is a monorepo built with:
+
+- **Desktop** — Electron 40.6 with CDP browser integration
+- **Server** — Node.js with Effect-ts service composition
+- **Web** — React + Vite 8 + TanStack Router
+- **Contracts** — Shared schemas (Effect Schema) for type-safe RPC
+- **Shared** — Common utilities and models
+- **Package Manager** — Bun 1.3.9
+
 ## Some notes
 
-We are very very early in this project. Expect bugs.
+We are very early in this project. Expect bugs.
 
 We are not accepting contributions yet.