TinyMediator 1.1.1

TinyMediator

A lightweight implementation of the Mediator pattern—with built-in source generation for automatic handler registration. Designed for minimal boilerplate and fast compile-time discovery.

Installation

via Nuget:

Install-Package TinyMediator

This will register both the mediator classes and the source-generating analyzer.

Features

This library is intended to be clean and purpose-built, without fluff. But it does include:

• ✅ A mimimal mediator abstraction, supporting "fire-and-forget" and typed responses
• ✅ Source-generated DI registration (no reflection)
• ✅ Configurable handler lifetimes (scoped by default)
• ✅ No unnecessary marker interfaces

Basic Usage

1. Define a Request and Handler

public class Ping { }

public class PingHandler : IRequestHandler<Ping, Pong>
{
    public Task<Pong> Handle(Ping request, CancellationToken cancellationToken)
        => Task.FromResult(new Pong());
}

2. Register Handlers Automatically

Add this line (or equivalent) to your Program.cs and all of your IRequestHandler implementations will be automatically registered from the generated source at compile time.

services.AddTinyMediatorHandlers();

3. Send Requests

var response = await mediator.Send(new Ping());

Handler Lifetimes

By default, handlers are registered with a scoped lifetime for easy use of scoped services like HttpClients and DbContexts. If you want your handler to have a different lifetime, you can declare that:

[HandlerLifetime(TinyMediator.ServiceLifetime.Singleton)]
public class PingHandler : IRequestHandler<Ping, Pong>
{
    public Task<Pong> Handle(Ping request, CancellationToken cancellationToken)
        => Task.FromResult(new Pong());
}

What's Inside

Contributions

There are many robust (and complicated, or commercial) libraries out there that implement the Mediator pattern. I made this library for the simplest use cases and wanted source generation to automate registrations without using reflection. If this is generally useful to others I might be surprised, but any suggestions or contributions are welcome.

License

MIT - Use, modify, and distribute it freely in open source and commercial projects.