API Acceptable Use Policy

This Acceptable Use Policy (AUP) covers the use of the Nexus Mods API in all third party websites, applications or other use cases. As an extension of our Fair Use Policy, it is meant to inform developers of what is and is not acceptable when it comes to requesting and using data from our services. 

We provide an open API for developers and their applications to interact with our database. This access is offered freely in the spirit of facilitating the development of modding-related applications for the benefit of the modding community.

It is the responsibility of the application developer to ensure their compliance with the standards laid out in this document. Failure to meet these standards, intentionally or otherwise, may result in the Nexus Mods team taking action to prevent further use of our data by your application. 

Personal API keys

All users have the ability to generate a Personal API key, from the API Access page. This is intended to allow users to experiment with our API without using the keys assigned to a registered application. 

We tolerate the use of your personal API key with applications that are in the testing stage of development or are intended for personal use only. Please note that as soon as a public-facing application has left the testing stage and is intended to be utilised by a wider audience (i.e. end-users rather than a select group of testers) you should contact support@nexusmods.com to register your application as described in the registration process in this document.

We do not endorse or support the use of personal API keys in lieu of API keys generated for a public-facing application outside of the testing scenario described above and reserve the right to prevent abuse of personal API keys where applicable.

Registration process

In cases where your application is intended to be public-facing, we require you to contact the Nexus Mods support team once you have a testing build of the application which demonstrates the intended usage of our API. This will allow us to ensure not only that your application complies with this policy, but that it further does not consume an excess amount of API requests (which may result in users being rate limited).

In order to get your application registered, please follow these simple steps:

  1. Contact our support team (support@nexusmods.com) and include a testing build of your application which can be used with a personal API key. 
  2. Make any necessary changes to your application, then send us a name, short description and logo for your application. This will be displayed on the API Access page. All logos should be reasonably high resolution and be visible when displayed on a dark background. 
  3. Your application will then be issued a "slug" for use with the SSO.

Registered applications are listed on the API Access page accessible via the site preferences. Users have the ability to revoke the API key issued to your application at any time. 

Once your application has been registered you will be able to take advantage of our Single Sign-On (SSO) system. Although this is not a requirement, it is the most convenient way for users to add their API key to your application.

Please note that us registering an application does not imply an endorsement of the application, nor do we take any responsibility for the application functioning as intended. 

API access and open source

In the spirit of fostering cooperation between developers and in the modding community in general, we provide an open API and we release all of our software and tools as open source. 

Therefore, we strongly encourage any applications using our API to make use of open-source licensing, too. We reserve the right to deny registration to any applications if we have doubts about the nature of the application itself, the way our data and our users’ data is handled, or that the underlying code is fully complying with this policy.

Including the source code with your registration request will allow us to gain a better understanding of your application's intended purpose and may speed up the registration process.

Request Headers

When sending requests to the Nexus Mods API, we ask that you add appropriate information to the request header which identifies your application. Specifically including these fields:

Application-Version (e.g. "1.2.0") Please ensure this reflects the current release.
Application-Name (eg. "Vortex") Please keep this consistent across versions of your application.

This information will allow us to track usage of your application and inform you of any odd usage patterns which may be caused by a bug in the software. 

Unacceptable Usage

The following describes a number of example scenarios where the API or data retrieved from the API are being used improperly. Applications accessing our services in a comparable way may be actively blocked from using our API.

  • Fetching data en-masse with the intent to rehost this information on your own service (i.e. scraping).
  • Storing user API keys on your own server and/or using them without the action being initiated by the user. 
  • Using personal API keys for a public-facing application.
  • Sending request metadata which is either blank or impersonates another application. 

Please note that this is a non-exhaustive list and that we reserve the right to deem any usage which is detrimental to the modding community or Nexus Mods unacceptable at our sole discretion, with or without providing a reason.