# License

You don't need a license key to install and start Sentinel — see [Install with Docker](/docs/sentinel/install/docker/) to get running. Without one configured, Sentinel automatically runs on a **30-day trial**.

> **Warning:**
>
> A license is **required for production use**. The trial is meant for evaluation — configure a license key (Professional, or Enterprise, see [Pricing](/pricing/)) before relying on Sentinel for real traffic. Paid tiers also unlock capacity and features beyond the trial, such as [multi-replica deployments](/docs/sentinel/operations/clustering/), [SSO](/docs/sentinel/security/sso/), and [OpenTelemetry](/docs/sentinel/operations/monitoring-logging/#opentelemetry-enterprise).

## Configuring your license key

**Through the admin app:** **Admin → License**, enter your key, **Save**.

**Via environment variable:**

```
LICENSE_KEY=your-license-key
```

## License verification (call-home)

By default, Sentinel periodically verifies your license by contacting `eu.altcha.org`. As of version 1.15.0, this sends only minimal, non-telemetry details: application version, Node ID, and process ID.

### Offline verification

If you need to avoid call-home entirely (e.g. an air-gapped deployment), use `LICENSE_JSON` instead of `LICENSE_KEY` — set it to the full contents of the license file attached to your purchase confirmation email:

```
LICENSE_JSON={"...": "..."}
```

## Related

- **[Pricing](/pricing/)** — plan tiers and capacity.
- **[Clustering](/docs/sentinel/operations/clustering/)** — replica limits enforced by your license.
- **[ENV Variables](/docs/sentinel/operations/env-variables/#licensing)** — `LICENSE_KEY` / `LICENSE_JSON` reference.