Code Measure — AI vs Human Contribution Tracker

A VS Code extension that measures lines of code added/removed by AI (Kiro, Copilot, etc.) vs Human across sessions. Works with or without git — uses a local shadow index for non-git projects. Zero external dependencies.

Install

# From the .vsix file (no marketplace needed):
code --install-extension code-measure-1.0.0.vsix

Or in VS Code: Ctrl+Shift+P → "Extensions: Install from VSIX" → select code-measure-1.0.0.vsix

✨ Key Features

🎨 Colored Status Bar (Live Activity Indicator)

┌─────────────────────────────────────────────────────────┐
│ 🟢 GREEN  = Human Input (you are actively typing)       │
│ 🔵 BLUE   = AI Writing (Kiro/agent modifying files)     │
│ ⚪ WHITE  = Idle (no active coding detected)            │
└─────────────────────────────────────────────────────────┘

The status bar color changes in real-time based on who is currently coding. No manual action needed.

🔍 Smart AI vs Human Detection

Uses multiple behavioral signals (inspired by how git detects changes + Code Crawler's approach):

📁 Works WITHOUT Git (Non-GitLab/GitHub Projects)

The extension includes a Local Diff Engine — a git-like shadow index that:

1. Stores content hashes + full line snapshots of all tracked files
2. Computes actual line-level diffs (LCS algorithm, like git diff)
3. Works on ANY project folder, even without .git initialization
4. Uses the same approach as git: stat-based fast path + content-hash slow path

How Git detects changes (and how we replicate it locally):
┌─────────────────────────────────────────────────────────┐
│ 1. Check file stat (mtime + size) — FAST PATH           │
│    → If unchanged, skip                                 │
│ 2. If stat changed, hash content — SLOW PATH            │
│    → If hash same as index, no change                   │
│ 3. If hash differs, compute line diff (LCS/Myers)       │
│    → Get exact +added/-removed per file                 │
│ 4. Update index to new state                            │
└─────────────────────────────────────────────────────────┘

Shadow index stored in .code-measure/shadow-index/ (auto-gitignored).

How It Works

Automatic Mode (Default — No Action Required)

The auto-observer runs passively and:

• Detects when Kiro/AI writes files directly to disk (via FileSystemWatcher)
• Detects when you type in the editor (via onDidChangeTextDocument)
• Computes proper line-level diffs using the shadow index
• Classifies each change as AI or Human based on behavioral signals
• Records everything to .code-measure/ for reports

Manual Session Mode (Optional — For Precise Control)

1. Start Session (AI or Human)
   → Takes git snapshot (commit SHA) or shadow index baseline
2. You/AI write code...
3. End Session
   → Computes diff from snapshot
   → Records lines added/removed per file
   → Attributes to AI or Human
4. View reports, history, percentages

Commands (Ctrl+Shift+P)

Sidebar Panel

The extension adds a "Code Measure" activity bar icon with three views:

• Contribution Summary — AI% vs Human% at a glance, today's stats
• Sessions — List of all recorded sessions with line counts
• File History — Per-file breakdown showing who changed what

Status Bar

Two status bar items:

1. Activity Indicator (colored) — Shows current state:

   • 🟢 Human Input 23s — You're typing
   • 🔵 AI Writing 5s — Agent is modifying files
   • ⚪ Code Measure — Idle

2. Session Indicator — Shows active manual session:

   • 🤖 AI #5 12m30s — AI session running
   • 👤 HUMAN #6 3m — Human session running
   • 📊 Session — No active session

What's Measured

Settings

Data Storage

All data lives in workspace-local .code-measure/ folder:

.code-measure/
├── .gitignore              — Auto-excludes from git
├── sessions.jsonl          — Session records (append-only)
├── changes.jsonl           — Per-file change log (append-only)
├── prompts.jsonl           — Token/prompt tracking
├── project-meta.json       — Sequence counters & metadata
├── active/                 — Active sessions per VS Code instance
│   └── instance-{pid}.json
├── shadow-index/           — Git-like local diff engine
│   ├── index.json          — File metadata (hash, size, mtime)
│   └── blobs/              — Content snapshots for diff
│       └── {hash-prefix}/
│           └── {hash}.lines
└── reports/                — Generated markdown reports
    └── 2026/
        └── July/
            ├── daily-2026-07-05.md
            └── weekly-2026-06-30-to-2026-07-06.md

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                     Code Measure Extension                       │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  ┌──────────────┐  ┌───────────────────┐  ┌────────────────┐  │
│  │ Status Bar   │  │  Auto Observer    │  │  Session Mgr   │  │
│  │ Controller   │  │  (Passive)        │  │  (Manual)      │  │
│  │              │  │                   │  │                │  │
│  │ Green/Blue/  │◄─┤ • FS Watcher     │  │ • Start/End    │  │
│  │ White state  │  │ • Editor Monitor  │  │ • Continue     │  │
│  │              │  │ • Kiro Detector   │  │ • Git Diff     │  │
│  └──────────────┘  │ • Behavior Score  │  └────────────────┘  │
│                    └─────────┬─────────┘                       │
│                              │                                  │
│                    ┌─────────▼─────────┐                       │
│                    │ Local Diff Engine │                       │
│                    │ (Shadow Index)    │                       │
│                    │                   │                       │
│                    │ • Content hashing │                       │
│                    │ • LCS line diff   │                       │
│                    │ • Stat fast-path  │                       │
│                    │ • Blob storage    │                       │
│                    └─────────┬─────────┘                       │
│                              │                                  │
│                    ┌─────────▼─────────┐                       │
│                    │     Storage       │                       │
│                    │ (JSONL files)     │                       │
│                    └──────────────────┘                       │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Key Design Decisions

• No git required — Shadow index provides git-like diffs for any project
• Behavioral classification — Multiple signals weighted for accuracy
• Real-time status bar — See at a glance who's coding right now
• No external deps — Uses only VS Code API + Node.js built-ins
• Debounced processing — Handles Kiro's rapid multi-write patterns
• Content hashing — Accurate change detection (not just line count delta)
• LCS diff algorithm — Same approach as git for accurate +/-
• Multi-instance safe — PID-based session isolation
• Append-only storage — Safe for concurrent writes

Build from Source

cd code_measure
npm install
npm run compile
npm run package
# Produces code-measure-1.0.0.vsix