Platform & Open Source

GHG Calculator

One emissions engine, three interfaces, no API keys

Role
Author
Year
2026
Status
Open source, MIT licensed
967
embedded emission factors
6
peer-reviewed source databases
3
scopes covered
0
API keys required

The problem

Carbon accounting tools either put the factors behind a subscription or the methodology behind a dashboard. An agent asked to calculate emissions needs both the numbers and the audit trail, offline.

What we built

Decisions That Mattered

1.

Embed the factors

967 emission factors from six free, peer-reviewed sources ship with the package. No key, no network call, no vendor between the calculation and the citation.

2.

Serve the same engine three ways

A CLI for humans, an MCP server for agents, and a Claude Code skill for coding sessions all call one calculation core, so the three interfaces cannot disagree about a number.

3.

Show the derivation

Every result names the factor it matched, the basis on which it matched, and the source database, which makes the output reviewable by someone who did not run it.

4.

Render the report

Interactive HTML reports with maps turn a scope inventory into something a board can read, generated from the same run that produced the JSON.

What this demonstrates

Domain engines packaged for agent consumption, with the citation trail intact.

PythonuvMCPClaude Code skillGHG Protocol

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