# greencalculus/greencalculus-mcp [Health: Active]

**Category:** 🌳 Environment & Nature  
**Repository:** https://github.com/greencalculus/greencalculus-mcp  
**GitHub Stars:** 0  
**npm Downloads (last month):** 178  
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**Directory Page:** https://allmcps.com/mcp/greencalculus-greencalculus-mcp

## Description
Greenhouse-gas emission factors and carbon calculations (activity, embodied EN 15978, PCAF financed emissions) with source references and data versions.

## Tools
Capabilities this server exposes over MCP:

- **lookup_factor** — Fetch one emission factor by key, with its source and version
- **lookup_factors** — Fetch many factors by key in one call — a portfolio is one request, not one per factor
- **search_factors** — Search the 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 → 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

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "greencalculus-mcp": {
    "command": "npx",
    "args": ["-y","greencalculus-mcp"],
    "env": {
      "GREENCALCULUS_API_KEY": "",
      "GC_API_KEY": "",
      "GREENCALCULUS_MCP_URL": "",
      "GREENCALCULUS_MCP_TIMEOUT_MS": ""
    }
  }
}
```

**Requires environment variables:** `GREENCALCULUS_API_KEY`, `GC_API_KEY`, `GREENCALCULUS_MCP_URL`, `GREENCALCULUS_MCP_TIMEOUT_MS` — the values above are empty placeholders; fill in real credentials before running (see the repository for what each one is for).

## Documentation

## What greencalculus/greencalculus-mcp MCP server does

greencalculus/greencalculus-mcp MCP server exposes GreenCalculus greenhouse-gas data and calculation operations to MCP-compatible AI clients. It covers emission-factor lookup, factor search and resolution, activity-based emissions, electricity, embodied carbon under EN 15978, PCAF financed emissions, freight, spend-based EEIO, and business travel.

Responses include the source reference for each value and a pinned data version. This supports workflows where an emissions result needs to be cited, reviewed, or reproduced later. Returned emission-factor data carries the licence of its underlying source, which is identified in the response.

## How it works

The hosted service is available at `https://mcp.greencalculus.com`. A remote-MCP client can connect directly with an Authorization bearer token. The npm package and container image are thin stdio bridges: they forward JSON-RPC messages to the remote endpoint and return the remote response without special-casing individual methods.

The available operations include single and batch factor lookup, free-text search, mapping an informal description to a factor, and explanations when a factor is absent. Calculation tools handle unit conversion and GHG Protocol scope for activity data, location- and market-based electricity, lifecycle stages for embodied carbon, PCAF financed emissions, freight by mode and load, spend-based EEIO, and travel modes.

## Setup and configuration

For a remote client, configure the MCP URL and send `Authorization: Bearer YOUR_KEY`. For clients that only launch local processes, use `npx -y greencalculus-mcp` with `GREENCALCULUS_API_KEY`, or run `ghcr.io/greencalculus/greencalculus-mcp` through Docker. Docker must run with `-i` and without `-t`, because standard input and output carry the JSON-RPC stream.

`GREENCALCULUS_MCP_URL` changes the default endpoint, and `GREENCALCULUS_MCP_TIMEOUT_MS` controls the per-request timeout; the default is 120000 milliseconds. `GC_API_KEY` is accepted as an alias for the API key, but `GREENCALCULUS_API_KEY` takes precedence. Diagnostics are written to stderr, while stdout is reserved for JSON-RPC messages.

## Tools and capabilities

The twelve documented tools are:

- `lookup_factor` and `lookup_factors` retrieve one factor or multiple factors by key.
- `search_factors` searches the factor corpus by free text.
- `resolve_factor` matches a messy real-world description to a likely factor.
- `explain_absence` explains why a requested factor is unavailable.
- `calculate_activity` converts activity data into emissions with units and scope.
- `calculate_electricity` calculates location-based and market-based electricity emissions.
- `calculate_embodied` calculates EN 15978 embodied carbon and identifies missing lifecycle stages.
- `calculate_pcaf` calculates financed emissions with an audit trail.
- `calculate_freight`, `calculate_spend`, and `calculate_business_travel` cover freight, EEIO spend, and travel calculations.

These capabilities place the greencalculus/greencalculus-mcp MCP server in the Environment & Nature category for applications that need traceable carbon accounting rather than unsupported estimates.

## Limitations and notes

A key is not required for `initialize`, `tools/list`, `search_factors`, or `explain_absence`; other tools require one. The package is a bridge to the remote service, not a local copy of the calculation engine or factor corpus. The MIT licence covers the bridge, while data returned by the API follows the licence of its named source.

_Full upstream README: https://allmcps.com/mcp/greencalculus-greencalculus-mcp/readme_