AutoMapper

AutoMapper, a widely used object-object mapping library in the .NET ecosystem, has officially become a commercial product as of July 2, 2025. Jimmy Bogard, its creator, announced the launch of commercial editions for both AutoMapper and MediatR under a new company, Lucky Penny Software. The move aims to create a sustainable model for the long-term maintenance and development of these projects. The GitHub repository has been transferred to a new organization: LuckyPennySoftware/AutoMapper.

Why the Change?

The reasons for commercialization remain as Bogard previously outlined. As a solo consultant, he lacked the sponsored time he once had to dedicate to his open-source work. He concluded that the previous model was not sustainable for the projects' future growth.

"Taking time to see how things have been going on all fronts, I had a bit of a shock looking at my OSS work. I realized that model is not sustainable for the long-term success of these projects... I need to be able to pay for my time to work on these projects, and get direct feedback from paying clients..."

- Jimmy Bogard (Source)

Commercialization aims to fund dedicated time for improving the libraries, building the community, and responding to user needs more effectively.

Licensing and Pricing

AutoMapper has adopted a dual-license model: the Reciprocal Public License 1.5 (RPL-1.5) and a commercial license. The new commercial versions, starting with AutoMapper v15.0, are released on NuGet under this dual-license agreement.

The commercial license is tier-based on the number of developers:

• Standard: 1-10 developers
• Professional: 11-50 developers
• Enterprise: Unlimited developers

A free Community edition is also available for:

• Companies and individuals with less than $5,000,000 in gross annual revenue.
• Non-profits with less than $5,000,000 in annual budget.
• Educational and non-production environments.

A license key is required for auditing purposes but usage is not restricted by a missing or invalid key. For detailed pricing, see the official pricing page.

Previous versions of AutoMapper remain under their original licenses and are available in an archive repository.

Community Reaction to Initial Announcement

The initial announcement on GitHub Discussions (Source) and Reddit (Source) sparked conversation. While some expressed understanding, acknowledging the challenges of maintaining large OSS projects, others voiced concerns, particularly given AutoMapper's widespread use.

Suggestions for the commercial model emerged, including a hybrid or "conditionally free" open-source (cFOSS) license, where smaller entities could use it freely, while larger organizations might pay a fee (Source). This feedback appears to have influenced the final tiered model with a generous free community license.

Alternatives

The news prompted discussions about alternatives (Source):

1. Mapperly:

   • A .NET source generator that creates mapping code at compile time.
   • Pros: High performance (no runtime reflection), generated code is readable and debuggable, provides compile-time warnings for unmapped properties. Licensed under Apache 2.0.
   • Cons: Introduces a dependency (though only build-time), relies on source generator capabilities.

2. Mapster:

   • A fast, flexible, and type-safe object mapper for .NET. Licensed under MIT.
   • Pros: High performance, flexible, and type-safe.
   • Cons: Requires manual updates if object structures change.

3. Manual Mapping:

   • Simply writing the mapping code directly in C#.
   • Pros: Maximum control, no external dependency, clear and debuggable code. Often considered simpler in the long run despite initial boilerplate.
   • Cons: Can involve writing repetitive code, requires manual updates if object structures change.

Conclusion

AutoMapper's transition to a commercial model is now complete, providing a clear path for its future development and support. With a dual-license model that includes a free community tier, many users will be unaffected financially. However, larger organizations will need to purchase a license to use the latest versions, prompting them to evaluate the cost against the benefits or consider alternatives like Mapperly or manual mapping.

Links and References

• Jimmy Bogard: AutoMapper and MediatR Commercial Editions Launch Today
• AutoMapper Official Site: https://automapper.io/
• Jimmy Bogard: AutoMapper and MediatR Going Commercial
• GitHub: LuckyPennySoftware/AutoMapper
• GitHub (old repository): AutoMapper/AutoMapper
• GitHub: AutoMapper is going commercial (Discussion)
• Reddit: Automapper going commercial
• Reddit: Migrate out of automapper?
• Alternative: Mapperly
• Alternative: Mapster