# Authentication

Send your key in the `Authorization` header on every request:

```
Authorization: Bearer wm_live_…
```

- **Live keys** (`wm_live_…`) run on your account's credit.
- **Test keys** (`wm_test_…`) are free and return real results, but are limited to 10 requests a minute, 100 a day and 10 MB sources. Use them while you build.

Keys belong to an account. Create, name and revoke them at [watermark.ws/developers](https://watermark.ws/developers); a key is shown in full only when it is created. A revoked key stops working at once.

Keep keys on your server. Anyone with a live key can spend your credit.

[`GET /v1/account`](https://api.watermark.ws/docs/reference.md#get-account) shows the account behind a key: its balance, tier, and the key's limits.