# Authentication

Unified search infrastructure for AI

> API Base URL  https://api.anysearch.com

The AnySearch search API (/v1/*) supports flexible authentication. You can decide whether to send an API key based on where you are in your product lifecycle:

| Mode | Header format | Quota & rate limit policy |
| --- | --- | --- |
| Anonymous | No Authorization header | Rate-limited per client IP and metered against the daily free quota |
| Authenticated | Authorization: Bearer YOUR_ANYSEARCH_API_KEY | Billed against the paid quota attached to the key, with higher concurrency limits |

> Heads up: If you send an Authorization header but the key is invalid, disabled, or expired, the gateway returns 401 Unauthorized or 403 Forbidden — it will not silently fall back to anonymous mode.