> ## 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.

# Authentication

> Akhdar partner APIs use server-to-server authentication with X-API-Key.

Akhdar partner APIs use server-to-server authentication. Send your partner API key in the `X-API-Key` header when calling Contributions and Delivery Emissions operations. Customer applications must never use this credential or call these operations directly.

Akhdar issues a partner API key to your integration team after API access is granted. This page explains how to use a key but does not manage keys.

## Request headers

* `X-API-Key` is required for Contributions and Delivery Emissions operations.
* `X-Correlation-ID` is optional. When provided, it is echoed on every response.
* `Idempotency-Key` is required for delivery-emissions estimate creation, contribution confirmation, and emissions-association creation.

`Idempotency-Key` is the transport request-idempotency header. Reusing the same header with the same canonical payload returns the original result. Reusing it with conflicting immutable request data returns `idempotency_conflict`.

## Authentication errors

A missing, malformed, invalid, or revoked key returns HTTP `401` with the `unauthorized` code.

A write attempted while the partner is suspended returns HTTP `403` with the `partner_suspended` code.

For response formats and recovery guidance, see [Errors & Recovery](/errors-and-recovery).