gwittebolle/claude-carbon
216 stars · Last commit 2026-10-16
claude-carbon: track the carbon footprint of your Claude Code sessions
README preview
<p><img src="docs/banner.png" width="100%" alt="claude-carbon, free and open source: the CO2 of your Claude Code sessions, in the terminal and in the Claude app. Eight pixel molecules from dark blue to dark red, a terminal whose status line reads 8.2gCO2, and the /carbon-panel pane: this session's molecule and CO2, the last 30 days as tiles and warming stripes, a button for the yearly card"></p> [](https://github.com/gwittebolle/claude-carbon/stargazers) [](LICENSE) [](https://github.com/gwittebolle/claude-carbon/releases) [](https://www.npmjs.com/package/claude-carbon) [](https://github.com/gwittebolle/claude-carbon/actions/workflows/ci.yml) claude-carbon is an open source Claude Code plugin that tracks the carbon footprint of your sessions: a live CO2 estimate computed locally from your token usage, in the terminal status line and in the Code tab of the Claude desktop app, next to the session's API-equivalent cost. In the desktop app, `/carbon-panel` opens a pane with a pixel molecule coloured by this session's CO2 against the median of your past sessions, your usage over the period you pick, its warming stripes, and a button for your yearly card. ## What claude-carbon does - `/carbon-panel`: a pane in the Claude desktop app with your CO2 molecule, your usage and the warming stripes of your sessions (in a terminal, the session in the band above the prompt). See [the mod](#the-mod-carbon-panel-and-the-co2-of-each-answer) - Adds a live CO2 estimate to the Claude Code status line, and the session's CO2 under the prompt in the Claude desktop app, each next to the session's API-equivalent cost - Persists each session to a local SQLite database, so history survives the 30-day transcript purge - Backfills historical data from existing `~/.claude` transcripts - Slash commands: `/carbon-report` (text), `/carbon-card` (PNG), `/carbon-pr` (footprint of a pull request) - A README badge with your all-time total, and a public methodology with every factor sourced > **About the `$` figure.** It is an API equivalent: what your session would cost at Anthropic's pay-as-you-go API list prices. On a Pro or Max subscription you do not pay it; it shows the value of what you used, next to its CO2. See [How it works](#how-it-works).