> For the complete documentation index, see [llms.txt](https://docs.viesus.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.viesus.com/licensing/overview.md).

# Overview

VIESUS has two deployment models — **on-premise** and **cloud** — covering three distinct licensing mechanisms.

<table><thead><tr><th width="162.199951171875">License type</th><th width="131">Deployment</th><th width="305.4000244140625">Best for</th><th>Details</th></tr></thead><tbody><tr><td><strong>GUID</strong></td><td>On-premise</td><td>Deployments across multiple machines, containers, VMs, or cloud</td><td><a href="/pages/lCiACthr5Ckh7P2QtUsI">GUID licensing</a></td></tr><tr><td><strong>Activation Key</strong></td><td>On-premise</td><td>Trials and fixed on-premise machines</td><td><a href="/pages/aAKBRMjB1lIWaM76DECY">Activation Key licensing</a></td></tr><tr><td><strong>API Key + credits</strong></td><td>Cloud</td><td>API-based integrations, no on-premise install</td><td>See below</td></tr></tbody></table>

***

## On-premise licensing — GUID

A unique GUID is delivered with the software package and passed at runtime to unlock the library. The GUID has no machine binding — the same GUID works on any number of systems simultaneously, including VMs, containers, and cloud instances.

**Used for:** servers, Docker, Kubernetes, cloud infrastructure, anything that scales or moves between hosts.

A GUID license is arranged with Viesus AG — discuss with <info@viesus.com> when arranging your license.

See [GUID](/licensing/guid.md) for the full mechanism, key properties, and how to pass the GUID in each VIESUS interface.

***

## On-premise licensing — Activation Key

An Activation Key is bound to the target machine's hardware. After installation you generate a request file from the target machine and exchange it with Viesus AG for an activation file, which unlocks the library on that machine.

**Used for:** trials, dedicated workstations, fixed on-premise production machines.

See [Activation Key](/licensing/activation-key.md) for the step-by-step activation flow on Windows and Linux, including screenshots.

***

## Choosing between GUID and Activation Key

| Scenario                                         | Use            |
| ------------------------------------------------ | -------------- |
| Servers, VMs, Docker containers, cloud instances | GUID           |
| Deployments that may scale or move               | GUID           |
| Single fixed workstation or production server    | Activation Key |
| Trial or evaluation                              | Activation Key |

Use a GUID when you need to run across multiple machines, in containers, or on cloud infrastructure where the activation hardware would change. Use an Activation Key for trials and fixed on-premise machines.

***

## Cloud licensing

The VIESUS Cloud API uses a different model: **API key authentication** with **credit-based billing**. No library to install, no GUID, no expiry to manage.

**How it works:**

1. Create an account at [viesus.cloud](https://www.viesus.cloud).
2. Generate an API key in the dashboard at `https://www.viesus.cloud/app/api-keys`.
3. Pass the key as `x-api-key` on every API request.
4. Credits are consumed per enhancement.

**Credit model:**

| Feature             | Credits per image |
| ------------------- | ----------------- |
| Color Enhancement   | 1                 |
| Restoration         | 1                 |
| Background Handling | 4                 |
| AI Upscaling        | 4                 |

When multiple features are active, only the highest-cost feature is charged. See [Cloud: Credits](/reference/cloud-api/credits.md) for PDF formulas and subscription tier details.

***

## Contact

**On-premise licensing, renewals, or technical questions:** <info@viesus.com>

**VIESUS Cloud accounts:** [viesus.cloud](https://www.viesus.cloud)

**Software downloads:** [transfer.viesus.com](https://transfer.viesus.com)


---

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