> ## Documentation Index
> Fetch the complete documentation index at: https://docs.layerx1.com/llms.txt
> Use this file to discover all available pages before exploring further.

# One key, both protocols.

> Every request is authenticated with a key that starts with lx1_. How you present it depends on which protocol you are speaking.

## Getting a key

Keys are created and revoked in the dashboard under `/dashboard/keys`. A key is shown
once at creation — store it somewhere safe. Keys are always prefixed `lx1_`.

<Note>
  Treat keys as secrets. Set them through environment variables rather than committing
  them, and rotate from the dashboard if one leaks.
</Note>

## How to present the key

| Protocol                           | Endpoint               | Header                          |
| ---------------------------------- | ---------------------- | ------------------------------- |
| Anthropic Messages                 | `/v1/messages`         | `x-api-key: lx1_...`            |
| OpenAI Chat Completions            | `/v1/chat/completions` | `Authorization: Bearer lx1_...` |
| OpenAI Responses                   | `/v1/responses`        | `Authorization: Bearer lx1_...` |
| Embeddings / Completions / Batches | `/v1/...`              | `Authorization: Bearer lx1_...` |

The Anthropic endpoint also accepts `Authorization: Bearer lx1_...` as an alternative to
`x-api-key`, which is convenient when a client only lets you set one auth header.

## Examples

```sh title="Anthropic — x-api-key" theme={null}
curl https://api.layerx1.com/v1/messages \
  -H "x-api-key: lx1_your_key" \
  -H "content-type: application/json" \
  -d '{"model":"lx1-gpt-oss-120b","max_tokens":256,"messages":[{"role":"user","content":"Hi"}]}'
```

```sh title="OpenAI — Authorization: Bearer" theme={null}
curl https://api.layerx1.com/v1/chat/completions \
  -H "authorization: Bearer lx1_your_key" \
  -H "content-type: application/json" \
  -d '{"model":"lx1-gpt-oss-120b","messages":[{"role":"user","content":"Hi"}]}'
```

## Failure modes

* A missing or malformed key returns `401` with an `error` body shaped for the protocol
  you called.
* A valid key naming a model that does not exist in the catalog returns `404` — check the
  id against `GET /v1/models`.

See [Errors](/errors) for the full status-code reference and body shapes.