# etiqueta0.com auth.md

How AI agents and other automated clients authenticate with etiqueta0.com.

## Audience

AI agents, assistants, scripts and integrations that read data from etiqueta0.com, a Spanish buying guide to
vehicles with the DGT "etiqueta 0" (zero-emission) label.

## Registration

No registration is required. etiqueta0.com does not provision agent accounts, client IDs or API keys, and it does not
run an OAuth authorization server. There is no `/.well-known/oauth-protected-resource` or registration endpoint.

## Supported methods

- **Anonymous (no credentials).** Every public endpoint is read-only and open. Send plain HTTPS `GET` requests with no
  `Authorization` header.

Public endpoints:

| Endpoint | What it returns |
|---|---|
| `GET https://etiqueta0.com/api/ocasion` | Used cars with the etiqueta 0 label for sale right now (JSON) |
| `GET https://etiqueta0.com/api/estado` | Service status (JSON) |
| `GET https://etiqueta0.com/api/openapi` | OpenAPI 3.1 description |
| `GET https://etiqueta0.com/.well-known/api-catalog` | API catalog (RFC 9727) |
| Any page with `Accept: text/markdown` | The page as Markdown |

## Credential use

There are no credentials to obtain, store or send. Do not send tokens or cookies; they are ignored.

Please identify your agent in the `User-Agent` header and keep request rates reasonable: `/api/ocasion` is cached for
60 seconds and updated every 10 minutes, so polling more often brings nothing new.

## Endpoints agents must not use

- `POST /api/solicitud` sends a purchase enquiry to a car seller on behalf of a person. Only submit it when a human has
  explicitly asked you to, with their own name and contact details.
- `/api/redaccion/*` is the private newsroom. It requires a human login and is not available to agents.

## Contact

For higher volumes, other data or a dedicated key: contacto@etiqueta0.com. Documentation:
https://etiqueta0.com/desarrolladores