# Website Carbon Estimate

> Website Carbon Estimate is a paid API for AI agents from api.strale.io, paid per call via x402, $0.054001/call, status unknown (last checked 2026-09-15).

Estimates CO2 emissions per page view for a given website URL using the Website Carbon methodology, returning an A–F rating and annual emissions estimate.

## Facts

- Endpoint: GET https://api.strale.io/x402/website-carbon-estimate
- Price: $0.054001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-strale-io-3c0a1edb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7l2HdhZpqFw4iL3JIa2yc

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 api-strale-io-3c0a1edb
```

Example prompt: What's the carbon footprint of example.com per page view? Give me the Website Carbon rating and annual CO2 estimate.

## When to prefer this

Use this endpoint when you need a standardized, methodology-backed sustainability score for a website and want a letter grade (A–F) alongside numerical CO2 estimates. Prefer this over generic carbon calculators when you need the widely recognized Website Carbon rating specifically.

## Known failure modes

- Invalid or unreachable URL returns an error
- Missing required 'url' query parameter returns validation error
- Rate limiting or payment failure returns 402 or 429
- Domain resolves but page is inaccessible, leading to incomplete data

## How this service works

Estimate CO2 emissions per page view using the Website Carbon methodology. Returns rating A-F, annual estimate.

## Output

Returns a carbon rating on an A–F scale, estimated CO2 grams per page view, and an annual CO2 emissions estimate for the given website URL, calculated using the Website Carbon methodology.

## Example request

```json
{
 "url": "https://www.example.com"
}
```

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-strale-io-3c0a1edb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)