Doc77 — Local Document Preview & Management · Markdown · PDF · MCP Server · LAN Sharing

Document viewer | Document manager | Markdown reader | PDF viewer | Code viewer | Knowledge base | Local document server

Open-source · Free · Cross-platform · Mobile-ready · Zero-config · 📦 Desktop app

Doc77 is a lightweight local document previewer, MCP file-operation bridge, and AI conversation-driven document management agent. Your browser is the workbench — supports Windows / macOS / Linux / WSL. Also available as an Electron desktop app for non-technical users, double-click to use. Can be safely exposed to the internet with password protection.

In read-only mode it's a multi-project showcase; in write mode it's an intelligent steward that asks for your approval — every file operation is confirmed by you before execution, backed by built-in security review, atomic transaction rollback, and cross-drive fault tolerance.

Preview

Dashboard	Document Preview

Login	Mobile

Use Cases

Scenario	Description
📚 Personal Knowledge Base	Point to a local folder and browse it like a knowledge base. A lightweight alternative to Obsidian / Notion, with your files always under your control
📝 Technical Writing	Write Markdown with instant preview. TTS read-back for proofing. MDX and Mermaid diagram support — a documentation engineer's tool
🎓 Academic Research	Manage papers (PDF) + notes (MD) + experimental code in one project directory. AI summarization for quick literature scanning
🏠 NAS / Home Server	Run doc77 on your NAS, access your document library from any device in the house. Password-protected. Unified entry for photos, docs, e-books
💼 Remote Work	VPN into your office computer and browse documents from a browser — no remote desktop needed. Bandwidth-efficient, memory-light
🔧 Ops Troubleshooting	View logs and config files on a server. With MCP, let AI assist in diagnostics. The approval mechanism ensures no accidental damage
🎤 Technical Interviews	Share a code or design doc link with candidates in one click. Their browser renders it directly — no screen sharing required
🐳 Docker Deployment	Mount a document volume and start the container. CI/CD artifact docs become instantly previewable
📡 LAN Meeting Sharing	One person runs doc77 start --bind 0.0.0.0, everyone on the LAN opens it in their browser. Review requirements docs or design proposals on your own device
📱 Mobile Access	Phone/tablet adaptive UI — browse project docs during commutes or at client sites. Responsive design, consistent experience across desktop and mobile
🔄 Win+WSL Hybrid	Write code in WSL, work in Windows. Skip SSH or terminal less — doc77 start --bind 0.0.0.0 and preview from your Windows browser or phone
🤖 Agent / MCP Development	Built-in MCP Server (stdio + HTTP) with 8 tools exposing filesystem capabilities. Debug agents while watching file changes and approving write operations from the Web UI
🪟 Windows Productivity	Completely free document preview tool. Markdown, PDF, Office, code highlighting all in one place
🗄️ Multi-project Management	Register once, remember forever. Dashboard for unified switching. Favorites, recent files, global search, directory tree — browse local docs like an IDE
🔒 Secure Team Sharing	One-click LAN sharing + password protection. Documents stay on your device, never land on anyone else's. Approval workflow keeps write operations under control
⚡ Zero-config Document Portal	npm install -g → doc77 register → open browser. No nginx, no Apache, three minutes to your own private document portal

Current Focus

Doc77 prioritizes preview experience, complemented by lightweight editing. Text files can be quickly edited and saved in-page (with external change conflict detection); heavy editing launches VS Code or your system editor with one click. Current focus:

• 🚀 Performance — Instant startup, smooth with large files
• 🐛 Stability — Multi-platform compatibility, eliminate experience bugs
• ✨ Preview Quality — Format support, reading tools, AI assistance pushed to the limit

Capabilities

Module	Details
Multi-format Preview	Markdown (GFM/KaTeX/Mermaid/PlantUML/Footnotes/Admonitions), PDF, Word/Excel, 44+ code languages with syntax highlighting, image Lightbox, JS/Python sandbox execution
Reading Tools	TTS read-aloud, auto-scroll, reading progress, in-doc search (Ctrl+F), global search, outline panel, bookmarks, recent files
Multi-tab & Editing	Multiple document tabs (LRU render cache), drag-and-drop temp file preview, lightweight text editing (external change conflict detection), one-click VS Code launch
AI Assistant	Natural language conversation (SSE streaming), doc summarization, smart categorization, batch operation planning. Supports DeepSeek/OpenAI/Qwen/Kimi/Doubao/GLM and custom endpoints
MCP & Approval	MCP Server (stdio + HTTP) with 8 tools exposing filesystem; all write operations queued for approval, CLI and Web dual-channel
Transaction Rollback	Pre-flight check + Shadow backup + reverse-order rollback. Failed batch operations auto-recover, orphaned shadow GC
Export & Share	Self-contained HTML export (inline styles and images, preserves light/dark theme), LAN read-only sharing links (with TTL, QR code, one-click revoke)
Offline Translation	Opus-MT ONNX models fully local (en↔zh), auto-language detection, translate-on-select + long-doc segment translation, no data leaves your machine
Multilingual UI	English / 简体中文 built-in, auto-detects browser and system language, extensible via ~/.doc77/locales/<lang>.json — add any language
Project Import	Obsidian vault ([[wikilink]] resolution), Git project batch scan, VS Code workspace import, tech-stack tag recognition
Mobile Companion	Scan QR code from Dashboard to open mobile view, mDNS LAN discovery, adaptive mobile UI
Electron Desktop	Windows / macOS / Linux one-click install, native file dialogs, system tray, vendor resources built-in (default port 28888)
Modular Plugins	AI / MCP / Translation optional installation (doc77 i ai / doc77 i translate), lightweight by default, expand on demand
Security	Path sandboxing, sensitive file filtering, envelope encryption (DEK), 10 one-time recovery codes, brute-force protection, session management, audit logging, password-protected external exposure
Offline-ready	doc77 vendor-install caches all CDN dependencies locally, fully functional without internet

Installation

Desktop (Recommended for non-technical users)

Platform	Download
Windows	📦 Doc77-Setup.exe
macOS	📦 Doc77.dmg
Linux	📦 Doc77.AppImage

Double-click to install, desktop shortcut launches the app. Native file dialog to select folders, ready out of the box.

CLI (Recommended for developers)

npm install -g idoc77                # Install
doc77 register ./my-docs --name "My Docs"   # Register a project
doc77 start                          # Start (127.0.0.1:27777)
doc77 start --bind 0.0.0.0           # Or allow LAN access

Command Reference

Core Commands

Command	Description
doc77 start [--port <n>] [--bind <addr>]	Start Web Dashboard (default port 27777; desktop 28888)
doc77 register <path> [--name <n>]	Register a project directory
doc77 list [--json]	List all registered projects
doc77 remove <id>	Remove a project by ID (does not delete source files)
doc77 update <id> [--name <n>] [--path <p>]	Update project name or path
doc77 status	Check service status

Configuration

Command	Description
doc77 config set <key> <value>	Set a config value
doc77 config get <key>	Get a config value
doc77 config list	List all config
doc77 config set-password	Set an access password (first time)
doc77 config change-password	Change access password
doc77 config reset-password	Reset password using recovery code
doc77 config reset-password --force	Force reset (clears encrypted config)
doc77 config recovery-codes	Regenerate recovery codes

Common config keys:

Key	Description	Default
ai.enabled	Enable AI assistant	false
ai.token	AI API token	—
ai.base_url	AI API base URL	https://api.deepseek.com
ai.model	Model name	deepseek-v4-pro
editor.default	Default editor	vscode
locale.language	UI/AI/CLI global language (empty = auto-detect)	—
translate.enabled	Enable offline translation	true
translate.mirror	Mirror download for models (hf-mirror.com)	false
export.share.ttl_hours	Share link TTL (hours)	24

MCP Service

Command	Description
doc77 mcp serve [--http] [--port <n>]	Start MCP service (stdio or HTTP transport)

Task Approval

Command	Description
doc77 approve --list	List pending approval tasks
doc77 approve --accept <task_id>	Approve a task
doc77 approve --reject <task_id>	Reject a task
doc77 approve --accept --all	Batch approve all
doc77 approve --reject --all	Batch reject all

Lock Management

Command	Description
doc77 lock status	View active project locks
doc77 lock release <project_id>	Manually release a project lock

Offline Support

# Download all CDN resources locally (~16MB)
doc77 vendor-install

# Skip Pyodide (Python runtime), save ~12MB
doc77 vendor-install --no-pyodide

# Download offline translation models (en↔zh, ~80MB each)
doc77 vendor-install --translate en-zh
doc77 vendor-install --translate zh-en

Resources are cached in ~/.doc77/vendor/ and auto-detected on restart. Re-running skips already-downloaded files.

Supported Formats

Format	Extensions	Read Mode
Markdown	.md .mdx .markdown	✅ TTS/Search/Outline/Progress
Mermaid	.mermaid .mmd	✅
Code (~44 langs)	.ts .js .py .go .rs .java .c .cpp .html .css .json …	✅ Syntax highlighting
PDF	.pdf	✅ Browser-native + fullscreen
Images (9 types)	.png .jpg .gif .svg .webp .avif .bmp .ico	✅ Lightbox zoom/nav
Word	.docx	✅ mammoth.js rendering
Excel	.xlsx .xls	✅ SheetJS + tab switching
JavaScript	.js	✅ Sandbox execution
Python	.py	✅ Pyodide WASM execution
Unsupported	.mp4 .zip .exe .shp .psd …	❌ File info card + show in folder

Markdown Features

Feature	Example	Status
Headers / Bold / Italic / Strikethrough	# H1, **b**, *i*, ~~del~~	✅ GFM
Lists (nested / ordered / unordered)	1., - , indent	✅ GFM
Task lists	- [x] - [ ]	✅ GFM
Tables (with alignment)	`	:---
Blockquotes / Horizontal rules	> quote, ---	✅ GFM
Images / Links / Image links	, [text](url)	✅ Local paths auto-rewrite to API
Code blocks + syntax highlighting	```python	✅ highlight.js (44+ languages)
Copy-to-clipboard button	hover top-right	✅
Math (inline / block)	$E=mc^2$, $$\int$$	✅ KaTeX
Mermaid diagrams	```mermaid	✅ Flow / Sequence / Gantt / Class / State / Pie
PlantUML diagrams	```plantuml	✅ kroki.io (offline falls back to source)
Emoji shortcuts	:smile: :rocket: :heart:	✅
Highlight marks	==highlight==	✅ <mark>
Footnotes	[^1] [^2]	✅
GitHub admonitions	> [!NOTE] > [!WARNING]	✅
Collapsible sections	<details><summary>	✅ Native HTML
Heading anchors	## My Heading → #my-heading	✅
Raw HTML	<kbd>, <sup>, <audio>, <video>	✅ Browser-native
Definition lists	Term : definition	❌
Auto TOC	[TOC]	⚠️ Outline panel replaces this

Offline Availability

Doc77 uses a vendor system for CDN → local fallback. doc77 vendor-install downloads resources to ~/.doc77/vendor/. The Electron desktop build bundles vendor resources at build time (extraResources).

Feature	Library	CLI vendor-install	Electron Built-in	Offline Fallback
Tailwind CSS	tailwind.js	✅	✅	3s timeout → unstyled
highlight.js	highlight.min.js	✅	✅	Code blocks lose highlighting
Mermaid	mermaid.min.js	✅	✅	Shows source
KaTeX	katex.min.js	✅	✅	Shows LaTeX source
XLSX	xlsx.mini.min.js	✅	✅	.xlsx not previewable
DOCX	mammoth.browser.min.js	✅	✅	.docx not previewable
Python	pyodide.js + wasm	⚠️ ~12MB extra	❌ Not bundled	.py not executable
PlantUML	kroki.io	❌ Needs internet	❌ Needs internet	Shows source

One-Command Restart

./scripts/restart.sh              # Default port 27777
./scripts/restart.sh --port 8080  # Custom port

To bind 0.0.0.0 for external access, use doc77 start --bind 0.0.0.0 (a password will be required).

Design Philosophy

1. Documents stay where they are — never copy or upload user files, read-only access to local paths
2. Preview ≠ Edit — let professional tools (VS Code / Typora) handle editing, let Doc77 handle preview
3. Register once, manage forever — register a project directory once, it's remembered permanently
4. Lightweight first — single process, SQLite, zero-config, out of the box
5. Conversation-driven — natural language interaction, AI-assisted planning, human final decision

Documentation

Document	Description
System Architecture	Complete design document
Architecture Review	Tech stack verification & architecture review
Implementation Plan	40 tasks, 9 phases detailed plan
Implementation Status	Real-time development progress
Changelog	Version history

Tech Stack

Component	Choice
Runtime	Node.js >= 22.x
Language	TypeScript ^5.8
Web Framework	Express 5.x
Database	SQLite (sql.js)
MCP Protocol	@modelcontextprotocol/sdk
Frontend	Vanilla HTML + CSS + JS (marked, Mermaid, highlight.js) + browser-native PDF / HTML preview
Build	tsup + pnpm workspaces
Test	Vitest

Project Structure

doc77/
├── packages/
│   ├── core/          # @doc77/core  Preview engine + FS abstraction + Express Server
│   ├── mcp/           # @doc77/mcp   MCP service layer + security guard + transaction system
│   ├── ai/            # @doc77/ai    AI provider + Agent core + Chat API
│   ├── cli/           # doc77 CLI    Command-line entry
│   ├── electron/      # Desktop shell (tray / native dialogs / port 28888)
│   └── doc77/         # idoc77 meta-package for npm publishing
├── docs/
│   ├── design/        # Design docs
│   ├── analysis/      # Analysis reports
│   └── planning/      # Implementation planning
├── scripts/           # Tool scripts
├── CLAUDE.md          # Project conventions
└── README.md          # This file

Privacy & Security

• All data stored locally in ~/.doc77/
• AI tokens encrypted in SQLite
• No file content sent to external servers (unless you manually enable AI features)
• Password-protected access supported

License

MIT License