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

# Authentication

> All server-to-server endpoints require a bearer API key.

All server-to-server endpoints require a partner API key, sent as a bearer token:

```
Authorization: Bearer <YOUR_API_KEY>
```

## Getting a key

Reach out to your Thrad contact to issue an API key for your partner / advertiser account. Keep keys server-side only — never embed them in browser code or mobile binaries.

## Errors

| Status                     | Reason                              |
| -------------------------- | ----------------------------------- |
| `401 Missing bearer token` | No `Authorization` header.          |
| `401 Invalid API key`      | Token doesn't match any active key. |