AutoMapperLite 4.4.0

<p align="center"> <picture> <source media="(prefers-color-scheme: dark)" srcset="docs/assets/logo-dark.png"> <img src="docs/assets/logo-light.png" alt="AutoMapperLite" width="360"> </picture> </p>

<p align="center"> <strong>v4.4.0</strong> · <a href="LICENSE">MIT License</a> · net6.0 – net10.0 · <a href="https://automapperlite.atkhssn.info">automapperlite.atkhssn.info</a> </p>

AutoMapperLite

A lightweight, customizable object-to-object mapping library for .NET projects. Designed to simplify DTO and entity mapping with easy-to-use profiles, support for nested properties, and flexible configuration — created and maintained by Atik Hassan.

Targets net6.0, net7.0, net8.0, net9.0, and net10.0.

4.4.0 is the current official release. All prior versions (4.0.2 and earlier) are deprecated — see CHANGELOG.md for release history.

📖 Full documentation (Getting Started, API reference, usage guide, performance, FAQ, comparison): automapperlite.atkhssn.info.

Features

• Simple, lightweight object mapping between source and destination types.
• Supports nested object mapping, including nested List<T> properties whose item types have a registered map.
• Fluent profile-based configuration similar to AutoMapper.
• Supports ForMember and ForPath for custom member and nested member mappings.
• Supports collection mapping to List<T>, arrays, and common collection interfaces (IList<T>, ICollection<T>, IReadOnlyList<T>, IReadOnlyCollection<T>, IEnumerable<T>).
• Integration via Dependency Injection (DI) — IMapperConfig and IMapper are both registered as singletons, since neither holds per-request state.
• Thread-safe: mapping configuration and the mapper itself can be used concurrently.
• Designed as a small NuGet package for internal project use.

Installation

Install the NuGet package in your project:

dotnet add package AutoMapperLite --version 4.4.0

1. Register AutoMapperLite in your DI container

In your Program.cs or startup configuration:

using System.Reflection;

var builder = WebApplication.CreateBuilder(args);

// Register all profiles from the executing assembly
builder.Services.AddAutoMapperLite(Assembly.GetExecutingAssembly());

var app = builder.Build();

2. Create Mapping Profiles

Define your mappings by creating classes inheriting from Profile and override Configure method:

using AutoMapperLite;
using AutoMapperLite.Interfaces;

public class MyMappingProfile : Profile
{
    public override void Configure(IMapperConfig config)
    {
        // Basic map
        config.CreateMap<Country, CountryViewModel>();

        // ForMember/ForPath functions must return the already-mapped value, not the raw
        // source sub-object — the library does not implicitly convert types for you. When
        // the source and destination property types differ (as here: Country vs.
        // CountryViewModel), map through the mapper itself inside the function.
        var mapper = new Mapper(config);

        // Map with ForMember for direct property mapping
        config.CreateMap<Organization, OrganizationViewModel>()
            .ForMember(dest => dest.CountryViewModel, src => mapper.Map<CountryViewModel>(src.Country));

        // Map with ForPath for nested properties
        config.CreateMap<Location, LocationViewModel>()
            .ForPath(dest => dest.OrganizationViewModel.CountryViewModel, src => mapper.Map<CountryViewModel>(src.Organization.Country));
    }
}

3. Inject and Use Mapper

Inject IMapper in your classes and map objects easily:

public class MyService
{
    private readonly IMapper _mapper;

    public MyService(IMapper mapper)
    {
        _mapper = mapper;
    }

    public LocationViewModel GetLocationViewModel(Location location)
    {
        return _mapper.Map<LocationViewModel>(location);
    }
}

API Overview

CreateMap<TSource, TDestination>()

Defines a mapping between source and destination types.

ForMember(destinationMember, sourceFunc)

Configures mapping for a single direct property of the destination object.

• destinationMember: Expression to specify a destination property (e.g. dest => dest.CountryViewModel)
• sourceFunc: Function to select source property/value.

ForPath(destinationPath, sourceFunc)

Configures mapping for nested properties within the destination object.

• destinationPath: Expression specifying a nested destination property path (e.g. dest => dest.OrganizationViewModel.CountryViewModel.Name)
• sourceFunc: Function to select source property/value.

When to use ForMember vs ForPath?

Supported Features

• Map single objects and collections (List<T>, arrays, IList<T>, ICollection<T>, IReadOnlyList<T>, IReadOnlyCollection<T>, IEnumerable<T>).
• Auto-mapping properties with the same name and compatible types.
• Custom member mapping via ForMember and ForPath.
• Nested object instantiation and mapping.
• DI-friendly registration with extension method AddAutoMapperLite.
• Profiles discovery from assemblies.

Folder Structure

AutoMapperLite/
│
├── Core/
│ ├── Mapper.cs # Core mapper logic and reflection
│ └── MapperConfig.cs # Mapping registry (CreateMap / GetMap / HasMap)
│
├── Mapping/
│ ├── MapBuilder.cs # Fluent mapping configuration builder (ForMember / ForPath)
│ └── Profile.cs # Base Profile class for defining maps
│
├── Interfaces/
│ ├── IMapper.cs # Mapper interface
│ └── IMapperConfig.cs # Mapper configuration interface
│
├── Extensions/
│ └── ServiceCollectionExtensions.cs # DI extension methods
│
├── AutoMapperLite.Tests/ # xUnit test project
├── AutoMapperLite.Benchmarks/ # BenchmarkDotNet benchmark project
├── docs/ # Static documentation site (deploys to automapperlite.atkhssn.info)
│
├── README.md # This documentation file
├── CHANGELOG.md # Release history
├── LICENSE # MIT License
├── CONTRIBUTING.md # Contribution guidelines
├── CODE_OF_CONDUCT.md # Contributor Covenant
├── SECURITY.md # Vulnerability reporting policy
└── AutoMapperLite.csproj # Library project file

Contributing

This package is designed for internal or commercial use in your projects. Feel free to fork, modify, and enhance as needed. Pull requests and suggestions are welcome — see CONTRIBUTING.md for how to get started, and CODE_OF_CONDUCT.md for community expectations.

For reporting security vulnerabilities, see SECURITY.md.

License

AutoMapper Lite is open-source software licensed under the MIT License.

You are free to use, modify, distribute, and use this software commercially, subject to the conditions of the MIT License.

Frequently Asked Questions

Is AutoMapperLite free and open source? Yes — MIT licensed, free for personal and commercial use. See License.

Which .NET versions are supported? net6.0, net7.0, net8.0, net9.0, and net10.0.

Is it thread-safe? Yes — configuration (CreateMap) and mapping (Map) can both be used concurrently; see the concurrency tests in AutoMapperLite.Tests.

How does it compare to AutoMapper or Mapster? AutoMapperLite is intentionally smaller in scope — no LINQ projection support, no convention/coercion engine, just CreateMap/ForMember/ForPath compiled into cached delegates per type pair. Choose it when you want a minimal-dependency mapper for straightforward DTO/entity mapping; choose AutoMapper or Mapster for large projects needing LINQ ProjectTo, value converters, or maximum raw throughput — see the real, measured comparison.

More questions answered in the full FAQ.

Contact

Project: AutoMapperLite · GitHub

Author: Atik Hassan · atik.hassan@outlook.com

Thank you for using AutoMapperLite! Happy Mapping 😊