Task 12: Add Related Work section (Section 21) to methodology covering EcoLogits, CodeCarbon, AI Energy Score, Green Algorithms, Google/Jegham published data, UNICC framework, and social cost research. Task 13: Add specific citations and links for cognitive deskilling (CHI 2025, Springer 2025, endoscopy study), linguistic homogenization (UNESCO), and algorithmic monoculture (Stanford HAI). Task 14: Add Related Tools section to toolkit README linking EcoLogits, CodeCarbon, and AI Energy Score. Also updated toolkit energy values to match calibrated methodology. |
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Claude Code Impact Toolkit
Track the environmental and financial cost of your Claude Code conversations.
What it does
A PreCompact hook that runs before each context compaction, capturing:
- Token counts (actual from transcript or heuristic estimate)
- Cache usage breakdown (creation vs. read)
- Energy consumption estimate (Wh)
- CO2 emissions estimate (grams)
- Financial cost estimate (USD)
Data is logged to a JSONL file for analysis over time.
Install
# Project-level (recommended)
cd your-project
./path/to/impact-toolkit/install.sh
# Or user-level (applies to all projects)
./path/to/impact-toolkit/install.sh --user
Requirements: bash, jq, python3.
View results
.claude/hooks/show-impact.sh # all sessions
.claude/hooks/show-impact.sh <session_id> # specific session
How it works
The hook fires before Claude Code compacts your conversation context. It reads the conversation transcript, extracts token usage data from API response metadata, and calculates cost estimates using:
- Energy: 0.1 Wh/1K input tokens, 0.5 Wh/1K output tokens (midpoint of range calibrated against Google and Jegham et al., 2025)
- PUE: 1.2 (data center overhead)
- CO2: 325g/kWh (US grid average for cloud regions)
- Cost: $15/M input tokens, $75/M output tokens
Cache-read tokens are weighted at 10% of full cost (they skip most computation).
Related tools
This toolkit measures a subset of the costs covered by
impact-methodology.md. For more precise environmental measurement,
consider these complementary tools:
- EcoLogits — Python library that tracks per-query energy and CO2 for API calls to OpenAI, Anthropic, Mistral, and others. More precise than our estimates for environmental metrics.
- CodeCarbon — Measures GPU/CPU energy for local training and inference workloads.
- Hugging Face AI Energy Score — Benchmarks model energy efficiency. Useful for choosing between models.
These tools focus on environmental metrics only. This toolkit and the methodology also cover financial, social, epistemic, and political costs.
Limitations
- All numbers are estimates with low to medium confidence.
- Energy-per-token figures are calibrated against published research (Google, Aug 2025; Jegham et al., May 2025), not official Anthropic data.
- The hook only runs on context compaction, not at conversation end. Short conversations that never compact will not be logged.
- This toolkit only works with Claude Code. The methodology itself is tool-agnostic.
- See
impact-methodology.mdfor the full methodology, uncertainty analysis, and non-quantifiable costs.
Files
impact-toolkit/
install.sh # installer
hooks/pre-compact-snapshot.sh # PreCompact hook
hooks/show-impact.sh # log viewer
README.md # this file
License
MIT. See LICENSE in the repository root.