mapstermapper/mapster

A fast, fun and stimulating object to object Mapper

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Summary Information

Updated 37 minutes ago
Added to GitGenius on September 13th, 2026
Created on May 30th, 2014
Open Issues & Pull Requests: 81 (+0)
GitHub issues: Enabled
Number of forks: 408
Total Stargazers: 5,168 (+0)
Total Subscribers: 75 (+0)

Repository Insights (GitGenius)

Median issue/PR response: 10.3 days
Mean response time: 222.9 days
90th percentile: 868.3 days
Tracked items: 262

Most active contributors

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How this project is maintained

Around half of the issues opened in the past year never receive a reply. 94% of open issues come from outside the core team, so the backlog reflects real-world use rather than internal planning. Work labelled "configuration problem" is answered fastest, typically in about an hour, while "waiting for info" waits about 3 weeks. Only 2% of issues opened in the past year have been closed. Three people close 87% of everything that gets resolved.

Charts & Analytics

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Issue Activity (beta)

Open issues: 62
New in 7 days: 0
Closed in 7 days: 0
Avg open age: 690 days
Stale 30+ days: 57
Stale 90+ days: 50

Recent activity

Opened in 7 days: 0
Closed in 7 days: 0
Comments in 7 days: 0
Events in 7 days: 0

Top labels

  • bug (43)
  • improvement (31)
  • waiting for info (29)
  • configuration problem (12)
  • feature request (11)
  • help wanted (10)
  • open for PR (4)
  • duplicate (3)

Detailed Description

Mapster is a code generator that automatically creates object-to-object mapping methods for C# applications.

The tool solves the problem of writing repetitive mapping code between domain objects, data transfer objects, and other types. Rather than manually implementing mapping logic, Mapster generates optimized mapping methods at compile time using code generation. This approach eliminates boilerplate while producing performant mapping code tailored to your specific type conversions.

Mapster suits projects that perform frequent object transformations, particularly those using layered architectures with DTOs, Entity Framework integration, or dependency injection patterns. The tool provides specialized packages for common scenarios: integration with Entity Framework Core and EF6, support for immutable types, JSON.NET compatibility, and dependency injection container setup. Teams should adopt it when mapping code represents a significant portion of their codebase or when performance of mapping operations matters. The README does not compare Mapster to alternative mapping libraries.

The project maintains active development with regular updates to its core packages and ecosystem. The tool receives ongoing refinement across its multiple specialized packages, indicating sustained investment in supporting diverse mapping scenarios. Documentation and tooling support remain current, with diagnostic packages available to help developers understand and debug generated mapping code.