# Gateway overview

The **Ethen Gateway** is the developer control plane for model requests. Lifecycle for this release: **public beta** (not GA). Claims below match certification evidence and the portfolio registry.

## How it works

1. Authenticate with an Ethen Gateway API key (`Authorization: Bearer <key>`).
2. Resolve the model against the Gateway catalog — or, for `ethen/*` smart
   aliases, resolve the alias to a concrete provider/model via the smart router
   ([Smart routing](/docs/gateway/smart-routing)).
3. Enforce project scope, rate/concurrency/budget limits when configured.
4. Call an upstream adapter (OpenAI, Anthropic, Vercel AI Gateway, …) using server credentials or caller-supplied keys where allowed.
5. Return an OpenAI-compatible completion shape with an `ethen` metadata namespace.
6. Record usage against dated price records only — never OCR-only or expired prices.

## Endpoints

| Endpoint | Method | Auth | Purpose |
|---|---|---|---|
| `/api/gateway/v1/chat/completions` | POST | API key required | Chat completion (stream and non-stream) |
| `/api/gateway/v1/models` | GET | Public catalog | List catalog models |
| `/api/gateway/v1/providers` | GET | Public catalog | List provider metadata (no secrets) |

## Authentication

```http
Authorization: Bearer <ethen_gateway_api_key>
```

Unauthenticated chat completion requests must fail closed (401/403 JSON). See [Authentication](/docs/gateway/authentication) and [Gateway quickstart](/docs/gateway/quickstart).

## Provider readiness

Gateway launch paths with current certification receipts (as of M9 evidence):

- OpenAI
- Anthropic
- Vercel AI Gateway (upstream adapter)

**Not** Gateway launch-ready in this release documentation:

- Gemini (no Gateway certification receipt)
- Exa (Research support; not a Gateway launch provider)
- Ollama (local read-only certification only)

Details: [Certification status and known limits](/docs/resources/certification-and-limits).

## Pricing honesty

Estimated cost uses only versioned `official_provider` price records with retrieval and expiry dates. Stale or OCR-only rows fail closed and must not be billed.

## Maturity

:::note
Gateway is **public beta**. Multi-instance limiter and invoice-fixture reconciliation are certified; live paid invoice matching and Gate K independent review remain **BLOCKED** where noted in certification evidence.
:::

## Related

- [Gateway quickstart](/docs/gateway/quickstart)
- [Providers, routing, and fallbacks](/docs/gateway/providers)
- [Deprecations](/docs/resources/deprecations)