claude-carbon
A Claude Code plugin that shows a session's CO2 estimate in the status line next to its cost
Low risk
We rate an entry low when it mostly gives the agent instructions and reference material.
Why this level
- It reads local token-usage data and writes it to a local database
- It installs Claude Code hooks; the computation needs no network
Install
In your terminal, with SkillFoxx CLI
npx skillfoxx add plugins/claude-carbonDetects the agents on your machine, checks the risk and pins the version.
Other ways to install
Run one by one in the Claude Code chat
/plugin marketplace add gwittebolle/claude-carbon
/plugin install claude-carbon@claude-carbonInstall the plugin with npx claude-carbon, then restart Claude Code so the estimate appears in the status line. See the report with /carbon-report.
Other ways from the author
npx claude-carbonInstalls and updates the plugin. Restart Claude Code afterward.
This is third-party code. Review the repository files before installing.
What it does
The plugin adds a live CO2 estimate to the Claude Code status line, computed locally from token usage. Each session is stored in a local SQLite database, so history survives the purge of old logs. It backfills from existing transcripts and offers commands: a text report, an image card and the footprint of a single pull request. A README badge can show the all-time total, and the methodology with sourced factors is public.
Who it is for. For developers who want to see the environmental footprint of their Claude Code sessions next to the cost.
Good fit when
- You want a session CO2 estimate right in the status line
- You need an emissions report for a period or a pull request
- You track a team's footprint and want a README badge
Not a fit when
- You do not use Claude Code
- You do not need an emissions estimate and the cost counter is enough
- You do not want to install hooks and a local database
Example request
Show the CO2 emissions report for the last week and build an image cardLimitations
This is an estimate from token usage, not an exact measurement; the factors and methodology are documented in the repository. It works with Claude Code. Installing from a third-party community marketplace may fail on an old pinned version, so the authors recommend their own install commands. MIT licensed.
How to disable. Uninstall the claude-carbon plugin through the plugin manager and, if you like, remove the local database and the README badge.
Security check
- It reads local token-usage data and writes it to a local database
- It installs Claude Code hooks; the computation needs no network
README in short
The README describes an open Claude Code plugin that puts a live CO2 estimate in the status line next to session cost. Data is stored in a local SQLite database and backfilled from existing transcripts. Slash commands give a text report, an image card and a pull-request footprint, and a README badge shows the all-time total. Install via npx or a script for macOS, Linux and WSL, with a separate Windows path. MIT licensed, with an open methodology of factors.
FAQ
Where does the emissions number come from?
It is computed locally from the session's token usage using open factors; the sourced methodology is in the repository.
Does data leave the machine?
No, history is kept in a local SQLite database on your machine.
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