jscan

A code quality analyzer for JavaScript/TypeScript vibe coders.

Building with Cursor, Claude, or ChatGPT? jscan performs structural analysis to keep your codebase maintainable.

Working with Python? Check out pyscn

Quick Start

# Run analysis without installation
npx jscan analyze src/

Demo

jscan-demo.mp4

Features

One command scores your whole codebase (0-100 with an A-F grade) and generates an HTML report that shows what to fix first.

jscan looks at your code from five angles:

• 🧹 Dead code - unreachable code, unused imports/exports, and orphan files you can safely delete
• 📋 Duplicate code - copy-pasted and structurally similar code worth merging (Type 1-4 clone detection)
• 🌀 Complexity - functions that are hard to read and test (cyclomatic complexity)
• 🏗️ Dependencies - circular imports and unstable module dependencies (Martin metrics, DOT graph export)
• 🧩 Class design - classes that depend on too much (CBO coupling)

Parallel execution • Built with Go + tree-sitter

AI Agent Integration

jscan ships Agent Skills that teach AI coding agents when and how to run each analysis: health checks, refactoring, architecture review, and CI-friendly reports.

Agent Skills (Recommended)

uvx add-skills ludo-technologies/jscan

This installs the Skills into your project. They work with Claude Code, Cursor, Codex, Gemini CLI, and many other agents (add --agent cursor etc. to target one, --global for all projects).

Then just ask your agent:

1. "Analyze the code quality of the src/ directory"

2. "Find duplicate code and help me refactor it"

3. "Show me complex code and help me simplify it"

Claude Code Plugin (Optional)

claude plugin marketplace add ludo-technologies/jscan
claude plugin install jscan@jscan-marketplace

The plugin installs the same Agent Skills through Claude Code's plugin system.

Installation

# Install globally with npm (recommended)
npm install -g jscan

Alternative installation methods

Build from source

git clone https://github.com/ludo-technologies/jscan.git
cd jscan
go build -o jscan ./cmd/jscan

Go install

go install github.com/ludo-technologies/jscan/cmd/jscan@latest

Common Commands

jscan analyze

Run comprehensive analysis with HTML report

jscan analyze src/                              # All analyses with HTML report
jscan analyze --format json src/                # Generate JSON report
jscan analyze --select complexity src/          # Only complexity analysis
jscan analyze --select deadcode src/            # Only dead code analysis
jscan analyze --select complexity,deadcode,clone src/  # Multiple analyses

jscan check

Fast CI-friendly quality gate

jscan check src/                         # Quick pass/fail check

jscan init

Create configuration file

jscan init                               # Generate jscan.config.json

jscan deps

Dependency visualization

jscan deps src/ --format dot | dot -Tsvg -o deps.svg

💡 Run jscan --help or jscan <command> --help for complete options

Configuration

Create a jscan.config.json or .jscanrc.json in your project root:

{
  "complexity": {
    "low_threshold": 10,
    "medium_threshold": 20,
    "enabled": true
  },
  "dead_code": {
    "enabled": true,
    "min_severity": "warning"
  },
  "output": {
    "format": "text",
    "show_details": true
  }
}

⚙️ Run jscan init to generate a configuration file with core options

Roadmap

• TypeScript-specific analysis features (type-aware dead code, generic complexity)
• Vue / JSX single-file component support
• IDE / editor integrations
• Watch mode for continuous analysis

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Documentation

📚 Development Guide • Architecture • Testing • Contributing

Enterprise Support

For commercial support, custom integrations, or consulting services, contact us at contact@ludo-tech.org

License

MIT License — see LICENSE

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Built with ❤️ using Go and tree-sitter