> ## Documentation Index
> Fetch the complete documentation index at: https://docs.akhdar-sa.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Use {baseUrl} for the environment-specific base URL provided to the partner integration team. Do not invent an API hostname.
> x-akhdar-* fields are publication provenance only. Do not treat them as partner integration instructions.

# Create a delivery-emissions estimate

> Creates an optional educational Well-to-Wheel delivery-emissions estimate. An estimate is
not environmental impact by itself and is not required to confirm a contribution.

**Inputs**
- Supported vehicle categories: `motorcycle_gasoline`, `car_gasoline`.
- Distance: `0 < distance_km <= 200`, at most three decimal places.
- `Idempotency-Key` is required.

**Factors**
- `motorcycle_gasoline`: `143.23 g CO₂e/km`
- `car_gasoline`: `207.51 g CO₂e/km`

**Calculation and display**
- `raw_emissions_gco2e = distance_km × emission_factor_gco2e_per_km`
- `estimated_emissions_kgco2e = raw_emissions_gco2e ÷ 1000`
- Customer display uses two decimals and round-half-up. Values below `0.01 kg CO₂e` are
  shown as `<0.01`, never `0.00`.

Unassociated estimates expire after 24 hours. If a confirmed contribution already exists
for the same partner, environment, and `partner_order_ref`, this request may create the
association. You can also associate later with
`POST /v1/impact-transactions/{transaction_id}/emissions-associations`. After association,
the immutable snapshot is the reporting record.

Reusing `Idempotency-Key` with the same canonical payload returns the original estimate.
A conflicting payload returns `idempotency_conflict`. Do not use `partner_order_ref` alone
as the estimate identity.




## API Specification

The full API specification for this endpoint is available in the [documentation index](https://docs.akhdar-sa.com/llms.txt).