💀 Dead Code Detector (AI-Powered)

A VS Code extension that uses Claude AI to find dead code that traditional static analysis misses.

What it detects

Category	Examples
🚫 Unreachable Logic	Code after return, impossible if conditions, catch blocks that hide errors
🔌 Unused APIs	Exported functions never called, orphaned classes, unused variables
🚩 Obsolete Feature Flags	const FEATURE_X = false guards, hardcoded toggles, deprecated flag checks

Setup

1. Install dependencies

npm install

2. Add your Anthropic API key

Option A — Settings UI:

1. Open VS Code Settings (Cmd+, / Ctrl+,)
2. Search for "Dead Code"
3. Paste your key into Dead Code Detector: Anthropic Api Key

Option B — Environment variable:

export ANTHROPIC_API_KEY=sk-ant-...

3. Run the extension

Press F5 in VS Code to open a new Extension Development Host window.

Usage

Action	How
Analyze current file	Cmd+Shift+D / Ctrl+Shift+D
Analyze current file	Right-click → "Dead Code: Analyze Current File"
Analyze workspace	Command Palette → "Dead Code: Analyze Entire Workspace"
Clear diagnostics	Command Palette → "Dead Code: Clear All Diagnostics"

Results appear as:

• Inline squiggles in the editor (Problems panel)
• Results panel (opens beside your editor) with filtering, severity badges, and jump-to-line

Configuration

// settings.json
{
  "deadCode.anthropicApiKey": "sk-ant-...",
  "deadCode.severity": "warning",        // error | warning | information | hint
  "deadCode.checks": {
    "unreachableLogic": true,
    "unusedApis": true,
    "obsoleteFeatureFlags": true
  }
}

Supported Languages

• JavaScript / TypeScript (.js, .ts, .jsx, .tsx)
• Python (.py)

Project Structure

src/
  extension.ts      # Entry point, command registration, diagnostics
  analyzer.ts       # Claude API call + prompt engineering
  resultsPanel.ts   # Webview results panel (HTML/CSS/JS)
package.json        # Extension manifest, commands, config schema
tsconfig.json

Architecture

User triggers command
        ↓
extension.ts → reads file + config
        ↓
analyzer.ts → calls claude-sonnet-4 with structured prompt
        ↓
Claude returns JSON array of issues
        ↓
extension.ts → creates VS Code Diagnostics (squiggles)
        ↓
resultsPanel.ts → renders filterable HTML panel

Extending

To add a new language, add it to activationEvents and isSupportedLanguage() in extension.ts.

To add a new check category, update the system prompt in analyzer.ts and add the category to the DeadCodeResult type.