GreenCode CLI (ecocode)

Measure the real energy & CO₂ impact of your code — right from the terminal.

GreenCode gives your codebase an energy class (A–G), like a home appliance, and can actually run your code to measure real CPU energy (mWh) and estimated CO₂.

npx ecocode@latest analyze

No install needed — npx runs the latest version.

Commands

analyze — static estimate of the whole folder (no setup)

Scans the current folder (AST), rates it A–G, and generates an online report.

npx ecocode@latest analyze
npx ecocode@latest analyze --max-files 50

profile <file> — real measurement of ONE file (no setup)

Actually executes a file and measures real user/system CPU → energy (mWh) and CO₂.

npx ecocode@latest profile ./dist/index.js

profile-project — real measurement of the WHOLE project (needs a config)

Runs several real scenarios of your project, each with a weight, and returns a weighted energy KPI for the whole codebase.

npx ecocode@latest init            # creates a starter ecocode.profile.json
# edit the scenarios to point at your real entrypoints, then:
npx ecocode@latest profile-project

Why does profile-project need ecocode.profile.json?

Because it measures real energy by actually running code — and only you know which files represent your app and how much each matters. You declare that once:

{
  "repeat": 3,
  "scenarios": [
    { "name": "API startup", "file": "./dist/server.js", "weight": 3 },
    { "name": "Daily batch", "file": "./dist/jobs/daily.js", "weight": 1 }
  ]
}

• file — a runnable entrypoint (.js / .mjs / .cjs).
• weight — how much that flow matters in real usage (higher counts more in the average).
• repeat — runs per scenario (more runs = less noise).

analyze and profile <file> need no config and work anywhere. Only the weighted whole-project measurement needs the JSON. Run ecocode init to scaffold it.

How energy is estimated

From the real measured CPU time:

Energy_mWh = (CPU_Time_ms × Standard_CPU_Wattage) / 3600

Defaults: Standard CPU power 65 W, grid carbon intensity 442 gCO₂e/kWh. These are transparent model constants (shown in the output), so the numbers are best used for relative comparisons (before/after an optimization) as well as absolute estimates.

Safety

profile and profile-project run code locally. Only profile files you trust.

Links

• Web app & full docs: https://green-code-swart.vercel.app