> ## Documentation Index
> Fetch the complete documentation index at: https://developer.hellgate.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> The Authentication API issues OAuth2 access tokens for Hellgate Cloud Platform services.

The Authentication API issues the **OAuth2 access tokens** used to call Hellgate Cloud Platform services. You
exchange a **client ID** and **client secret** for a token using the **client-credentials** grant, then send
the token as a bearer token on each request.

## Token endpoint

The token endpoint is hosted at `https://auth.eu1.hellgate.cloud`.

## Authentication

Send your client ID and client secret to the token endpoint using **HTTP Basic** authentication. The
**Request an access token** operation describes the request and response in full.

Tokens are scoped to an **audience** — the service instance they may call — and carry the **scopes** that gate
individual endpoints. The `audience` and `scope` parameters are both required on every token request; there
are no defaults, and each must fall within the limits provisioned on your client. For how a specific product
validates the token and which scopes and audience it requires, see that product's access guide — for example,
[Specter Authentication](/products/specter/authentication).