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# 🧪 Get Vehicle Carbon Emissions

GET https://api.catenatelematics.com/v2/intelligence/emission/vehicles/{vehicle_id}

Estimate a vehicle's CO2 emissions over a date window from odometer-derived miles traveled and an emission factor based on the vehicle's GVWR class and fuel type, decoded from its VIN via the NHTSA vPIC registry.

**Method:** Tank-to-wheel (tailpipe combustion) only — does not include upstream well-to-tank fuel-production emissions. See `method` on the response.

**Factors:** kg CO2/vehicle-mile by GVWR class, from the EPA GHG Emission Factors Hub (Table 8, distance-based method, January 2025 edition): Class 1 (Passenger Car) 0.297, Class 1-2a (Light-Duty Truck) 0.394, Class 2b-8 (Medium-/Heavy-Duty Truck) 1.298 — https://www.epa.gov/system/files/documents/2025-01/ghg-emission-factors-hub-2025.pdf . See `factor_version` on the response for which table version produced a given figure. Electric and CNG vehicles aren't covered by this table and return a null factor/co2.

**Window:** Defaults to the trailing 30 days. Supply `from_date` and `to_date` to request a custom range (max 90 days).

**Nullability:** `miles_traveled`/`co2_kg` are null when an odometer reading isn't available at both boundaries of the window. `gvwr_class`/`fuel_type`/`vehicle_class_bucket`/`emission_factor_kg_per_mile` are null when the vehicle has no VIN on file or the VIN couldn't be decoded. `vehicle_class_bucket`/`emission_factor_kg_per_mile`/`co2_kg` are also null when `fuel_type` isn't covered by the factor table (electric, CNG). These are independent of each other.

Reference: https://catena.ferndocs.com/api-reference/intelligence/emissions/get-vehicle-carbon-emissions

## Authentication

- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Request

### Path parameters

- `vehicle_id` (string, required)

### Query parameters

- `from_date` (date, optional, nullable) — Inclusive start of the emissions window. **Format:** YYYY-MM-DD **Default:** 30 days before yesterday. **Restriction:** `to_date - from_date` cannot exceed 90 days.
- `to_date` (date, optional, nullable) — Inclusive end of the emissions window. **Format:** YYYY-MM-DD **Default:** yesterday. **Restriction:** `to_date - from_date` cannot exceed 90 days.

## Response

### 200

Successful Response

- `vehicle_id` (string, required) — Catena vehicle identifier.
- `window` (VehicleEmissionWindow, required) — Date range used for the estimate.
- `vin` (string, required, nullable) — VIN on file for the vehicle. Null if none is recorded.
- `miles_traveled` (double, required, nullable) — Odometer-derived miles traveled over the window. Null if an odometer reading is missing at either boundary.
- `gvwr_class` (string, required, nullable) — Raw GVWR value decoded from the VIN via NHTSA vPIC (e.g. 'Class 8: 33,001 lb and above'). Null if the VIN is missing/undecodable or NHTSA is unavailable.
- `fuel_type` (string, required, nullable) — Raw FuelTypePrimary value decoded from the VIN via NHTSA vPIC (e.g. 'Diesel', 'Electric'). Null under the same conditions as gvwr_class.
- `vehicle_class_bucket` (enum, required, nullable) — Emission-factor bucket the GVWR class mapped to. Null under the same conditions as gvwr_class, if GVWR didn't match a recognized class, or if fuel_type isn't covered by this factor table (electric, CNG).
  - Allowed values: `1`, `1-2a`, `2b-8`
- `emission_factor_kg_per_mile` (double, required, nullable) — Emission factor applied (kg CO2 / vehicle-mile). Null under the same conditions as vehicle_class_bucket.
- `co2_kg` (double, required, nullable) — Estimated CO2 emissions in kg: miles_traveled x emission_factor_kg_per_mile. Null if either input is null.
- `method` ("tailpipe_only", optional, default: tailpipe_only) — Emissions accounting method used. v1: always tank-to-wheel tailpipe combustion, no upstream fuel-production emissions.
- `factor_version` (string, optional, default: v2) — Version identifier for the emission-factor table used to compute this estimate.

## Errors

### 400 Bad Request Error

Bad Request

- `code` (integer, optional, default: 400)
- `message` (string, optional, default: Bad Request)
- `detail` (string, optional, nullable)

### 401 Unauthorized Error

Unauthorized

- `code` (integer, optional, default: 401)
- `message` (string, optional, default: Unauthorized)
- `detail` (string, optional, nullable)

### 403 Forbidden Error

Forbidden

- `code` (integer, optional, default: 403)
- `message` (string, optional, default: Forbidden)
- `detail` (string, optional, nullable)

### 404 Not Found Error

Not Found

- `code` (integer, optional, default: 404)
- `message` (string, optional, default: Not Found)
- `detail` (string, optional, nullable)

### 405 Method Not Allowed Error

Method Not Allowed

- `code` (integer, optional, default: 405)
- `message` (string, optional, default: Method Not Allowed)
- `detail` (string, optional, nullable)

### 409 Conflict Error

Conflict

- `code` (integer, optional, default: 409)
- `message` (string, optional, default: Conflict)
- `detail` (string, optional, nullable)

### 422 Unprocessable Entity Error

Unprocessable Entity

- `code` (integer, optional, default: 422)
- `message` (string, optional, default: Invalid Request Body)
- `detail` (list of ValidationErrorDetail, optional, nullable)

### 429 Too Many Requests Error

Too Many Requests

- `code` (integer, optional, default: 429)
- `message` (string, optional, default: Too Many Requests)
- `detail` (RetryAfterDetail, optional, nullable)

### 500 Internal Server Error

Internal Server Error

- `message` (string, optional, default: Internal Server Error)

### 501 Not Implemented Error

Not Implemented

- `code` (integer, optional, default: 501)
- `message` (string, optional, default: Not Implemented)
- `detail` (string, optional, nullable)

## Types

### VehicleEmissionWindow

Date range covered by an emission response.

- `from_date` (date, required) — Inclusive start of the emissions window (YYYY-MM-DD).
- `to_date` (date, required) — Inclusive end of the emissions window (YYYY-MM-DD).

### ValidationErrorDetail

- `path` (string, required)
- `input` (string, required)
- `message` (string, required)
- `error_type` (string, required)

### RetryAfterDetail

- `retry_after_seconds` (integer, required)
- `message` (string, required)

## Examples

**Response**

```json
{
  "vehicle_id": "string",
  "window": {
    "from_date": "2023-01-15",
    "to_date": "2023-01-15"
  },
  "vin": "string",
  "miles_traveled": 1.1,
  "gvwr_class": "string",
  "fuel_type": "string",
  "vehicle_class_bucket": "1",
  "emission_factor_kg_per_mile": 1.1,
  "co2_kg": 1.1,
  "method": "tailpipe_only",
  "factor_version": "v2"
}
```

**SDK Code**

```python
import requests

url = "https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id"

headers = {"Authorization": "Bearer <token>"}

response = requests.get(url, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id';
const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.get("https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id")
  .header("Authorization", "Bearer <token>")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id");
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://api.catenatelematics.com/v2/intelligence/emission/vehicles/vehicle_id")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```