Repository files navigation

A lightweight and straightforward mediator implementation for .NET applications, facilitating in-process messaging with minimal setup.

Package	Version	Popularity
NetDevPack.SimpleMediator

If you found this project helpful or it assisted you in any way, please give it a star. It helps to support the project and the developers.

You can find complete example projects demonstrating how to use the SimpleMediator in the/samples folder.

These include:

• ✅ Basic usage withSend andPublish
• ✅ Modular application structure
• ✅ Manual and automatic registration of handlers

Feel free to explore and run them to see how the mediator works in different scenarios.

You can install the SimpleMediator package via NuGet Package Manager or the .NET CLI:

dotnet add package NetDevPack.SimpleMediator

To reference only the contracts for SimpleMediator, which includes:

• IRequest (including generic variants)
  • Represents a command or query that expects a single response
• INotification
  • Represents an event broadcast to multiple handlers (if any)

This example demonstrates how to combine aRequest (command/query) and aNotification (event) in a real-world use case.

✅ This scenario uses onlyMicrosoft.Extensions.DependencyInjection.Abstractions for DI registration — no framework-specific packages.

publicclassCreateCustomerCommand:IRequest<string>{publicstringName{get;set;}}publicclassCustomerCreatedEvent:INotification{publicGuidCustomerId{get;}publicCustomerCreatedEvent(GuidcustomerId){CustomerId=customerId;}}

publicclassCreateCustomerHandler:IRequestHandler<CreateCustomerCommand,string>{privatereadonlyIMediator_mediator;publicCreateCustomerHandler(IMediatormediator){_mediator=mediator;}publicasyncTask<string>Handle(CreateCustomerCommandrequest,CancellationTokencancellationToken){varid=Guid.NewGuid();// Simulate persistence...// Publish eventawait_mediator.Publish(newCustomerCreatedEvent(id),cancellationToken);return$"Customer '{request.Name}' created with ID{id}";}}publicclassSendWelcomeEmailHandler:INotificationHandler<CustomerCreatedEvent>{publicTaskHandle(CustomerCreatedEventnotification,CancellationTokencancellationToken){Console.WriteLine($"Sending welcome email to customer{notification.CustomerId}");returnTask.CompletedTask;}}

You can register everything manually if you want full control:

services.AddSingleton<IMediator,Mediator>();services.AddTransient<IRequestHandler<CreateCustomerCommand,string>,CreateCustomerHandler>();services.AddTransient<INotificationHandler<CustomerCreatedEvent>,SendWelcomeEmailHandler>();

Or use assembly scanning with:

services.AddSimpleMediator();

publicclassCustomerAppService{privatereadonlyIMediator_mediator;publicCustomerAppService(IMediatormediator){_mediator=mediator;}publicasyncTask<string>CreateCustomer(stringname){returnawait_mediator.Send(newCreateCustomerCommand{Name=name});}}

When theCreateCustomer method is called:

1. CreateCustomerHandler handles the request
2. It creates and persists the customer (simulated)
3. It publishes aCustomerCreatedEvent
4. SendWelcomeEmailHandler handles the event

This structure cleanly separatescommands (which change state and return a result) fromnotifications (which communicate to the rest of the system that something happened).

• Lightweight: Minimal dependencies and straightforward setup.
• In-Process Messaging: Facilitates in-process communication between components.
• Handler Registration: Automatically registers handlers from specified assemblies.

NetDevPack.SimpleMediator targets .NET Standard 2.1, and is compatible with .NET Core 3.1+, .NET 5+, .NET 6+, .NET 7+, .NET 8, and newer versions of the .NET runtime.

NetDevPack.SimpleMediator was developed byEduardo Pires under the MIT license.