GreenCalculus MCP¶
Sourced greenhouse-gas emission factors and audit-traced carbon calculations as an MCP server - every value comes back with its exact source cell and a pinned data version, so an agent hands back a number a person can cite and a machine can reproduce instead of a guess. The server is remote-first: point your client at the URL with a Bearer key, or use the thin stdio/Docker bridge for clients that can only spawn local processes.
Server type: Remote (Streamable HTTP, hosted) with stdio/Docker bridge
Auth: Bearer API key (free key at greencalculus.com)
Endpoint: https://mcp.greencalculus.com
Official registry: com.greencalculus/api
Tools: 11 (factor lookup/search/resolve + 8 calculators)
Category: Compliance / ESG
Built by: jeremiahsay (GitHub, MIT)
Why This Matters for Operators¶
CSRD and supplier ESG programs have turned carbon numbers from marketing copy into audited disclosures - and most of the numbers floating around are LLM guesses with no source. GreenCalculus attacks exactly that failure mode: every factor carries its source and version, explain_absence says why a factor does not exist instead of returning nothing, and the calculators are explicit about what they omit (for example, embodied-carbon runs flag missing lifecycle stages under EN 15978). The output is reproducible: same inputs, same pinned data version, same number - which is what an auditor actually wants.
The factor tools close the researcher's loop: search the corpus by free text, resolve a messy real-world description ("cubic meter of ready-mix concrete in France") to the best-matching factor, and fetch one factor by key with provenance. The emission-factor data returned by the API carries the license of its underlying source, named in every response.
Tools & Capabilities¶
| Tool | What it does |
|---|---|
lookup_factor |
Fetch one emission factor by key, with its source and version |
search_factors |
Search the factor corpus by free text |
resolve_factor |
Map a messy real-world description to the best-matching factor |
explain_absence |
Say why a factor does not exist, rather than returning nothing |
calculate_activity |
Activity to emissions, with unit conversion and GHG Protocol scope |
calculate_electricity |
Location-based and market-based electricity |
calculate_embodied |
Embodied carbon (EN 15978), explicit about missing lifecycle stages |
calculate_pcaf |
PCAF financed emissions, with the audit trail |
calculate_freight |
Freight by mode, distance and load |
calculate_spend |
Spend-based EEIO |
calculate_business_travel |
Business travel across modes |
Installation¶
claude mcp add --transport http greencalculus https://mcp.greencalculus.com --header "Authorization: Bearer YOUR_KEY"
For stdio-only clients: npx -y greencalculus-mcp with GREENCALCULUS_API_KEY, or Docker (docker run -i --rm -e GREENCALCULUS_API_KEY greencalculus/mcp - the -i flag is required and -t must be omitted). GC_API_KEY is accepted as an alias for the key variable.
Configuration¶
{
"mcpServers": {
"greencalculus": {
"url": "https://mcp.greencalculus.com",
"headers": { "Authorization": "Bearer YOUR_KEY" }
}
}
}
Free keys at greencalculus.com. A REST API with docs and Python/JS SDKs is also published (greencalculus.com/developers).
Business Relevance¶
- CSRD-reporting companies get audit-traced calculations with pinned data versions and named sources instead of unauditable LLM math.
- Supply-chain and procurement teams calculate freight, spend and activity emissions inside the agent that runs their vendor analysis.
- Financial institutions use the PCAF tool for financed-emissions estimates with a full audit trail.
- Sustainability consultants resolve messy client descriptions to correct factors with provenance, and explain gaps honestly.