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

# Authentication

> How to authenticate with the Rekko AI API.

All API requests require authentication. Pass your API key as a Bearer token in the `Authorization` header.

## Bearer token

```bash theme={null}
Authorization: Bearer rk_free_your_key_here
```

<CodeGroup>
  ```bash cURL theme={null}
  curl https://api.rekko.ai/v1/markets \
    -H "Authorization: Bearer rk_free_your_key_here"
  ```

  ```python Python theme={null}
  import httpx

  client = httpx.Client(
      base_url="https://api.rekko.ai/v1",
      headers={"Authorization": "Bearer rk_free_your_key_here"},
  )

  markets = client.get("/markets").json()
  ```

  ```javascript JavaScript theme={null}
  const resp = await fetch("https://api.rekko.ai/v1/markets", {
    headers: { Authorization: "Bearer rk_free_your_key_here" },
  });
  const markets = await resp.json();
  ```
</CodeGroup>

## Key prefixes

| Prefix     | Plan             |
| ---------- | ---------------- |
| `rk_free_` | Free tier        |
| `rk_pro_`  | Pro subscription |

## Getting a key

Sign up at the [dashboard](https://rekko.ai/dashboard) or via the API:

```bash theme={null}
curl -X POST https://api.rekko.ai/v1/customers/signup \
  -H "Content-Type: application/json" \
  -d '{"email": "you@example.com", "name": "Your Name"}'
```

<Warning>
  Your API key is shown **only once** in the signup response. Store it securely.
</Warning>

## Key rotation

Rotate your key from the [dashboard](https://rekko.ai/dashboard). The old key is revoked immediately.

## Error responses

| Status                  | Meaning                                           |
| ----------------------- | ------------------------------------------------- |
| `401 Unauthorized`      | Missing or invalid API key                        |
| `403 Forbidden`         | Valid key but insufficient tier for this endpoint |
| `429 Too Many Requests` | Rate limit or monthly quota exceeded              |

All errors return JSON:

```json theme={null}
{
  "detail": "Invalid or expired API key"
}
```

## Alternative auth methods

### RapidAPI

If you subscribe via [RapidAPI](/integrations/rapidapi/overview), use RapidAPI's standard headers instead of a Bearer token. Rekko validates the `x-rapidapi-proxy-secret` automatically.

### x402 Micropayments

For crypto-native agents, you can pay per-request with USDC on Base L2. See [x402 payments](/integrations/x402/overview).