# Licensing and Redistribution
## Content
Document Solutions Image Viewer can be used under the following licenses:
* No License
* Evaluation License
* Production License
# No License
When downloaded, the product works with full features in unlicensed mode. The product has the following limitations when it is used without license.
| **Scenarios** | **Licensing Watermark** |
| --------- | ------------------- |
| In the development mode, that is on deploying the application on local host, a banner with the following text is displayed on the left hand side corner: | *"Powered by Document Solutions Image Viewer.*
*You can deploy this EVALUATION version locally.*
*Temporary license keys are available for testing.*
*Email [us.sales@mescius.com](mailto:us.sales@mescius.com)*" |
| In the production mode, that is on deploying the application on a web server or domain, an error panel with the following message appears: | *"License Not Found.*
*You need a valid license key to run Document Solutions Image Viewer.*
*Temporary keys are available for evaluation.*
*If you purchased a license, your key is in your purchase confirmation email.*
*Email [us.sales@mescius.com](mailto:us.sales@mescius.com) to get your temporary key or if you need assistance with an existing license."* |
# Evaluation License
DsImageViewer is available to users for free evaluation for 30 days. To evaluate the product, you can write to us at [us.sales@mescius.com](mailto:us.sales@mescius.com) and obtain an evaluation license key for the specified domain. The evaluation license key expires after 30 days from the day it was generated.
| **Scenarios** | **Licensing Watermark** |
| --------- | ------------------- |
| With evaluation license, you can use all the features of the product, while it displays a banner displaying the following text: | *"Powered by Document Solutions Image Viewer.*
*Your temporary license key expires in {0} day(s)."* |
| Once the evaluation license expires, all toolbar buttons get disabled and an error panel with the following message appears: | *"Powered by Document Solutions Image Viewer.*
*Your temporary license key has expired.*
*Contact [us.sales@mescius.com](mailto:us.sales@mescius.com) for help.*" |
| If you wish to evaluate DsImageViewer without the evaluation banner on the local host before deploying it on the production server, you can request a special evaluation license by writing to us at [us.sales@mescius.com](mailto:us.sales@mescius.com). This license lets you use all the features of the control without any banner or error frame in the development mode. If you deploy the same to a production server, nothing is displayed in the viewer and error panel showing the following text gets displayed: | *"License Not Found*
*You need a valid license key to run Document Solutions Image Viewer.*
*Temporary keys are available for evaluation.*
*If you purchased a license, your key is in your purchase confirmation email.*
*Email [us.sales@mescius.com](mailto:us.sales@mescius.com) if you need assistance.*" |
# Production License
You get the production license issued at the time of purchase of [Document Solutions for Imaging](https://developer.mescius.com/document-solutions/dot-net-imaging-api). Once you apply a valid license key to the product, you can use all the features of DsImageViewer without any limitations, banner, error or watermark. However, if you apply license key registered for different domain or product is applied, following licensing watermarks appear.
| **Scenarios** | **Licensing Watermark** |
| --------- | ------------------- |
| A license key is specific to the domain it was generated for. Although in the development mode, all the product features work as usual, DsImageViewer appears blank when deployed on a different domain and the product displays an error frame with the following text: | *"Invalid License Key*
*This license key is for another Hostname(s).*
*Please verify the correct license for this site.*
*If you need assistance, please contact [us.sales@mescius.com](mailto:us.sales@mescius.com).*" |
| If an invalid license key is entered, nothing is displayed in the viewer. | *"Invalid License Key*
*Contact [us.sales@mescius.com](mailto:us.sales@mescius.com) to purchase a Document Solutions Image Viewer license.*" |
| If key for a different product is used, nothing is displayed in the viewer. | *"This license key is for a different MESCIUS product.*
*Contact [us.sales@mescius.com](mailto:us.sales@mescius.com) to purchase a Document Solutions Image Viewer license."* |
| If key for an older version product is used, nothing is displayed in the viewer. | *"This license key is for an older (\) version of Document Solutions Image Viewer.*
*Contact [us.sales@mescius.com](mailto:us.sales@mescius.com) to update your license."* |
# Apply License
To apply license key to a **DsImageViewer** instance, you can set the long string license key obtained through e-mail to **LicenseKey** property of the **DsImageViewer** class. You must set this property before the code that references the JavaScript files and even before you create and initialize the viewer.
```
// Add your license
DsImageViewer.LicenseKey = 'YOUR LICENSE KEY';
// Add your code
const viewer = new DsImageViewer("#viewer1");
```