GreenCalculus SDKs

Official client libraries for the GreenCalculus API — sourced greenhouse-gas emission factors and audit-traced calculations. Every value comes back with the exact place in the source it came from and the data version it was read at, so you return citable numbers instead of guesses.

Not writing code? The same corpus is a spreadsheet formula: the Google Sheets add-on has been listed and Google-verified since 11 September 2026 — see sheets/.

Try it with no API key

The corpus is open to read. Nothing to sign up for:

pip install greencalculus

from greencalculus import GreenCalculus

gc = GreenCalculus()                                    # no key

f = gc.factor("grid.gbr.electricity.location_based")
print(f["value"], f["unit"])                       # 0.13096 kg CO2e per kWh
print(f["factor"]["source"]["cell_ref"])           # 'UK electricity'!E25
print(f["factor"]["citation"]["proof_url"])        # a page anyone can check it on

That citation line is a published specification — five fields, the upstream publisher named before us, and free for anyone to implement, including against their own data.

import { GreenCalculus } from "greencalculus";

const gc = new GreenCalculus();                         // no key
const f = await gc.factor("grid.gbr.electricity.location_based");
console.log(f.value, f.unit, f.factor.source.cell_ref);

Don't know the key? Search for it — also keyless:

for row in gc.search("diesel litre")["factors"]:
    print(row["key"], row["factor"]["value"], row["factor"]["unit"])

A free key (no card) adds the seven calculation engines and as_of= version pinning:

gc = GreenCalculus(api_key="gc_live_...")
r = gc.ghg_activity(activity={"value": 1000, "unit": "kWh"},
                    factor_key="grid.gbr.electricity.location_based")
print(r["emissions"]["value"], r["source"]["id"])

Language	Package	Install
Python	./python	pip install greencalculus
JavaScript / TypeScript	./js	npm install greencalculus
Google Sheets	./sheets	=GC_FACTOR("grid.gbr.electricity.location_based")
Postman	./postman	import the collection

What you get

• 16,000+ sourced factors across grid, fuels, freight, refrigerants, AFOLU, CBAM, construction and spend-based EEIO. Every value returns its source reference, licence and uncertainty.
• Seven calculation engines — GHG Protocol activity, PCAF financed emissions, embodied EN 15978, electricity, freight, spend-based, business travel. The full working, never just a total.
• Reproducible — a deterministic receipt hash on every result, and as_of= pins any factor to a past data version so a figure re-runs identically in an audit.
• Checkable by the reader — every factor has a permanent verification page showing the publisher, the document, the exact place within it and whether it may be republished.
• Agent-native — the same data over MCP at mcp.greencalculus.com.

Use it from an AI agent (MCP)

GreenCalculus runs as a remote MCP server, so Claude — or any MCP client — can look up a factor or run a calculation mid-conversation and hand back the source with the answer, not just a number.

{ "mcpServers": { "greencalculus": { "url": "https://mcp.greencalculus.com", "headers": { "Authorization": "Bearer gc_live_..." } } } }

12 tools: lookup_factor · lookup_factors · search_factors · resolve_factor · explain_absence · calculate_activity · calculate_embodied · calculate_pcaf · calculate_electricity · calculate_freight · calculate_spend · calculate_business_travel

lookup_factors batches a list of keys into one call instead of one per key; explain_absence answers why a factor you expected is not there, which is usually the question behind "do you have X?".

Listed on the official MCP registry as com.greencalculus/api and on Smithery. Discovery (listing tools) is open; calling a tool needs a free key.

Missing a factor? Think a number is wrong?

• Request a factor — the corpus grows from these.
• Report a wrong value — a carbon figure that is quietly wrong is worse than one that is missing. Every factor's verification page names the cell we read; if it doesn't say what we say it says, tell us in public.
• Discussions — questions, ideas, and what you've built.

Links

• Docs: https://greencalculus.com/developers/docs
• OpenAPI 3.1 spec: spec/openapi.json · live at https://api.greencalculus.com/openapi.json
• Data rights, continuity & redistribution: https://greencalculus.com/developers/trust
• Status: https://greencalculus.com/developers/status
• Contributing: CONTRIBUTING.md · Security: SECURITY.md

MIT licensed. The licence covers these clients; emission-factor data carries the licence of its underlying source, named in every response.