Licensing warning from LuckyPennySoftware.MediatR included in template

[mheidari988]

Hi @jasontaylordev , thanks for the Clean Architecture template, it’s been very helpful.

After installing the template and building a fresh project, I noticed the following warning at startup:

You do not have a valid license key for the Lucky Penny software MediatR.
This is allowed for development and testing scenarios.
If you are running in production you are required to have a licensed version.

This appears to come from LuckyPennySoftware.MediatR.

I wanted to ask whether the inclusion of a licensed third-party MediatR package is intentional in the template, or if this warning is unexpected/unintended.

Specifically:

Is this dependency required for the template to function as designed? because one year ago I used your template for a project and there was not such a warning.

Is there an alternative (license-free) option that users are expected to swap in?

I ask mainly because the template is often used as a starting point for production systems, and unexpected licensing requirements can be surprising for new users.

Thanks again for your work, and happy to follow any recommended approach.

[jasontaylordev]

Hi @mheidari988,

Yes, this warning is expected - MediatR went commercial in mid-2025. I covered this in my announcement here: #1346

The key points:

• MediatR remains free for individuals and companies with less than $5 million USD in annual revenue
• The warning you're seeing is just informational - it doesn't block anything
• For development and testing, no license is required regardless of company size
• If your organization exceeds the revenue threshold and is running in production, you'd need a commercial license from mediatr.io

For the vast majority of users (especially those using this template as a learning resource or for smaller projects), there's nothing you need to do. The free tier covers most use cases.

I discussed my reasoning for continuing to use MediatR and AutoMapper in the announcement - essentially, the maturity, documentation, and community support of these libraries outweighs the licensing considerations for enterprise projects where the cost would be negligible anyway.

Hope that clarifies things!

[fernandopj-tecnol]

@jasontaylordev Unfortunately, this commercial license has a wider impact.

This entire project has been picked up as a reference for many LLM Coding Agens (I've seen it with Gemini and GTPOSS). Many bootstrap projects at this point are using it.
A client has been almost affected by it. A developer suggested a dotnet app with the MediatR package, unaware of licensing. This client far exceeds the limitation. Their logs caught it before going to production.
As a warning for other like me who found this discussion, below is a fragment of a Bedrock agent reasoning for keeping the software even after being questioned by the user.

Please don't consider my posting here as a criticism, I mean it as a warning for other developers using AI to code .NET projects.

---

About the "LuckyPennySoftware.MediatR" Error:

The error message you're seeing ("warn: LuckyPennySoftware.MediatR.License[0]...") indicates that there's a proprietary or third-party package named "LuckyPennySoftware.MediatR" installed in your environment, which is not the standard MediatR library.

This is likely due to:

• A previous installation of a commercial/proprietary version of MediatR
• A corrupted package cache
• An incorrect package reference in your local environment

How to Resolve the Warning:

1. Clear the package cache:

   dotnet nuget locals all --clear

2. Rebuild the project:

   dotnet restore
   dotnet build

3. Ensure you're using the standard MediatR package: The project files correctly reference <PackageReference Include="MediatR" Version="14.1.0" /> which is the legitimate, open-source version.