Green Software Engineer for Claude Code

A Claude Code agent and skill that embeds Green Software Foundation sustainability practices directly into your development workflow.

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What's Included

File	Type	Purpose
.claude/agents/green-software-engineer.md	Agent	On-call sustainability consultant for Q&A, architecture advice, and deep code audits
.claude/skills/green-software/SKILL.md	Skill	Passive green review that auto-triggers when writing backend code

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Documentation

Page	Description
Agent Guide	How to invoke @green-software-engineer — use cases, invocation syntax, and knowledge base
Skill Guide	How /green-review works — auto-trigger rules, checklist categories, and output format

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Quick Start

Prerequisites

• Claude Code v1.0 or later — available as a CLI, desktop app, or IDE extension (VS Code, JetBrains)
• A Claude Code subscription (no additional API keys required)

1. Copy the .claude/ folder into your project

your-project/
└── .claude/
    ├── agents/
    │   └── green-software-engineer.md
    └── skills/
        └── green-software/
            └── SKILL.md

Or for personal use across all projects, place them under your global config:

~/.claude/
├── agents/
│   └── green-software-engineer.md
└── skills/
    └── green-software/
        └── SKILL.md

2. Open your project in Claude Code

claude

3. Start using them

Ask the agent a question:

@green-software-engineer what's the greenest way to handle image uploads at scale?

Run an explicit green review:

/green-review

Let the skill work passively — write a new API endpoint or database query and Claude will automatically apply the green review checklist before responding.

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Agent: @green-software-engineer

A senior green software engineer persona grounded in:

• The 8 GSF Principles — GSF (Green Software Foundation) defines eight pillars: Carbon, Electricity, Carbon Intensity, Embodied Carbon, Energy Proportionality, Networking, Demand Shaping, and Measurement & Optimisation
• The SCI Standard (ISO 21031:2024) — SCI (Software Carbon Intensity) is a formula for measuring how much carbon a software system emits per unit of work: SCI = ((E × I) + M) / R
• Green Software Patterns from patterns.greensoftware.foundation

Example invocations:

@green-software-engineer review this API handler for carbon efficiency
@green-software-engineer how would I calculate an SCI score for this service?
@green-software-engineer is polling better or worse than websockets from a green perspective?
@green-software-engineer audit this Terraform config for over-provisioning

→ Full documentation in docs/agent-guide.md

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Skill: /green-review

A structured sustainability review checklist that covers:

• ⚡ Energy Efficiency — loops, lazy vs eager loading, polling patterns
• 🌐 Network Efficiency — payload size, round trips, CDN usage
• 🗄️ Compute & Storage — query optimisation, caching, data retention
• ☁️ Cloud & Infrastructure — provisioning, scale-to-zero, region selection, time-shifting
• 🔋 Hardware & Embodied Carbon — utilisation, managed vs self-managed

Auto-triggers when writing: API endpoints, database queries, cloud config, background jobs, data pipelines, caching logic.

Severity ratings: 🔴 High / 🟡 Medium / 🟢 Low / ✅ Already Green

→ Full documentation in docs/skill-guide.md

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Agent vs Skill — Quick Reference

	Agent	Skill
Invoke with	@green-software-engineer	Auto, or /green-review
Best for	Q&A, architecture, deep audits	Passive guardrail while coding
Runs in	Isolated context window	Your main conversation
Output	Conversational, advisory	Structured checklist

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References

• Green Software Foundation
• GSF Patterns Library
• SCI Specification
• Green Software Practitioner Course
• SCI for AI Standard
• SOFT Framework