Templates

MonadicSharp.Templates is a .NET template package that scaffolds production-ready projects with MonadicSharp pre-configured.

Installation

dotnet new install MonadicSharp.Templates

Verify installation:

dotnet new list | grep monadic

monadic-api

A Minimal API project with:

• Result<T> on all service methods
• EF Core 8 + AppDbContext
• UserService that returns Result<User> — ready to extend
• Match in endpoints to map errors to HTTP status codes

dotnet new monadic-api -n MyApi
cd MyApi
dotnet run

Project structure

MyApi/
├── Data/
│   └── AppDbContext.cs
├── Models/
│   └── User.cs
├── Services/
│   └── UserService.cs       ← returns Result<T>
└── Program.cs               ← endpoints use Match

Example endpoint (from the template)

app.MapPost("/users", async (CreateUserRequest req, UserService svc) =>
{
    var result = await svc.CreateAsync(req);
    return result.Match(
        onSuccess: user  => Results.Created($"/users/{user.Id}", user),
        onFailure: error => error.Type switch
        {
            ErrorType.Validation => Results.BadRequest(error.Message),
            ErrorType.Conflict   => Results.Conflict(error.Message),
            _                    => Results.Problem(error.Message)
        });
});

monadic-clean

A Clean Architecture solution with CQRS:

• Domain, Application, Infrastructure, API layers
• Command and Query handlers that return Result<T>
• IUserRepository with Result-aware EF Core implementation
• Email value object with validation via Result<T>

dotnet new monadic-clean -n MyApp
cd MyApp
dotnet build

Solution structure

MyApp/
├── src/
│   ├── MyApp.Domain/
│   │   ├── Entities/User.cs
│   │   ├── Repositories/IUserRepository.cs
│   │   └── ValueObjects/Email.cs         ← Result<Email> factory
│   ├── MyApp.Application/
│   │   ├── Users/Commands/               ← CreateUser, UpdateUser, DeleteUser
│   │   └── Users/Queries/                ← GetUserById, GetAllUsers
│   ├── MyApp.Infrastructure/
│   │   ├── Data/AppDbContext.cs
│   │   └── Repositories/UserRepository.cs
│   └── MyApp.Api/
│       ├── Controllers/UsersController.cs ← Match at the boundary
│       └── Program.cs
└── MyApp.sln

Example command handler

public async Task<Result<UserDto>> Handle(CreateUserCommand command)
{
    var email = Email.Create(command.Email);  // Result<Email>
    if (email.IsFailure) return email.Error;

    return await _repository
        .ExistsAsync(email.Value)
        .Bind(exists => exists
            ? Result<User>.Failure(Error.Conflict("Email already registered"))
            : Result<User>.Success(new User(command.Name, email.Value)))
        .Bind(user => _repository.AddAsync(user))
        .Map(user  => new UserDto(user));
}

AI assistant setup

Both templates include:

• .cursorrules — Cursor IDE generates MonadicSharp code by default
• .github/copilot-instructions.md — GitHub Copilot follows MonadicSharp patterns
• claude-system-prompt.md — Claude system prompt for MonadicSharp-first suggestions

No configuration needed — open the project and the AI assistant is already guided.

Uninstall

dotnet new uninstall MonadicSharp.Templates