# fittings EPA Carbon Estimate

> fittings EPA Carbon Estimate is a paid API for AI agents from fittings.sh, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Estimates CO2-equivalent emissions for fuel combustion, electricity consumption, freight transport, or passenger travel using US EPA emission factors

## Facts

- Endpoint: GET https://fittings.sh/v1/epa/carbon-estimate
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fittings-epa-carbon-estimate-02feca53
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1isRptPst3iVuoy6jxSlm

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fittings-epa-carbon-estimate-02feca53
```

Example prompt: Using EPA emission factors, estimate the CO2e for burning 500 units of natural gas as fuel.

## When to prefer this

Choose this endpoint when you need standardized, US EPA-backed CO2e estimates for fuel combustion, electricity use, freight movement, or passenger travel. It is ideal for Scope 1/2/3 emissions accounting, sustainability reporting, and carbon footprint calculations that require defensible, regulation-aligned emission factors. Prefer this over generic carbon calculators when US EPA methodology is explicitly required or when dealing with US-centric energy grids and transport modes.

## Known failure modes

- Missing required 'activity' or 'quantity' query parameters returns a 400 error
- Invalid or unsupported fuel type string for activity=fuel returns an error
- Invalid mode value for freight or passenger-travel activity returns an error
- Unrecognized eGRID subregion for electricity activity may return an error or fall back to national average
- Negative or zero quantity values may return an error or zero result

## How this service works

Estimate CO2e for fuel burned, electricity used, freight moved or a trip taken, using published US EPA emission factors.

## Output

Returns a CO2e (carbon dioxide equivalent) estimate for the specified activity, including the quantity, units, emission factor applied, and the total greenhouse gas output in a standardized unit, based on published US EPA emission factors.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "activity",
      "quantity"
     ],
     "properties": {
      "fuel": {
       "type": "string",
       "description": "activity=fuel: natural-gas | motor-gasoline | diesel | jet-fuel | propane | aviation-gasoline | residual-fuel-oil | biodiesel | ethanol | bituminous-coal | wood"
      },
      "mode": {
       "type": "string",
       "description": "activity=freight: truck | rail | water | air; activity=passenger-travel: car | light-truck | motorcycle | bus | commuter-rail | transit-rail | intercity-rail | air"
      },
      "region": {
       "type": "string",
       "description": "activity=electricity: eGRID subregion, default us"
      },
      "activity": {
       "type": "string",
       "description": "fuel | electricity | freight | passenger-travel"
      },
      "quantity": {
       "type": "number",
       "description": "fuel: units of that fuel; electricity: kWh; freight: short ton-miles; passenger-travel: one-way miles"
      },
      "passengers": {
       "type": "number",
       "description": "passenger-travel only; ignored for vehicle-basis modes"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fittings-epa-carbon-estimate-02feca53/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fittings.sh](https://www.zero.xyz/host/fittings.sh/llms.txt)