Samples

Real-world integration samples for API, Worker, Minimal API, and keyed dispatch scenarios.

API sample

// Handlers (CreateOrderHandler, OrderCreatedEventHandler) are discovered
// and registered automatically by the source generator.
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddNetMediate();

var app = builder.Build();
app.MapPost("/orders", async (IMediator mediator, CreateOrder command, CancellationToken ct) =>
{
    var created = await mediator.Request<CreateOrder, OrderCreated>(command, ct);
    return Results.Ok(created);
});

app.Run();

Worker sample

// SyncCommandHandler is discovered and registered automatically by the source generator.
var builder = Host.CreateApplicationBuilder(args);
builder.Services.AddNetMediate();
builder.Services.AddHostedService<Worker>();

await builder.Build().RunAsync();

public sealed class Worker(IMediator mediator) : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            await mediator.Send(new SyncCommand(), stoppingToken);
            await Task.Delay(TimeSpan.FromMinutes(1), stoppingToken);
        }
    }
}

Minimal API sample

// CreateOrderHandler is discovered and registered automatically by the source generator.
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddNetMediate();

var app = builder.Build();
app.MapPost("/orders", async (IMediator mediator, CreateOrder command, CancellationToken ct) =>
{
    var created = await mediator.Request<CreateOrder, OrderCreated>(command, ct);
    return Results.Ok(created);
});

app.Run();

Keyed dispatch sample

Register handlers under routing keys and dispatch selectively at runtime. The key flows through the entire pipeline, making it available to every behavior for contextual decisions such as queue selection or tenant routing.

// Registration — handlers share a message type but differ by key
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddNetMediate(configure =>
{
    configure.RegisterCommandHandler<DefaultOrderHandler, ProcessOrder>();        // null key → "__default"
    configure.RegisterCommandHandler<PriorityOrderHandler, ProcessOrder>("priority"); // keyed
});

var app = builder.Build();

// Dispatch to the default (null-key) handler
app.MapPost("/orders", async (IMediator mediator, ProcessOrder cmd, CancellationToken ct) =>
{
    await mediator.Send(cmd, ct);
    return Results.Accepted();
});

// Dispatch to the "priority" handler
app.MapPost("/orders/priority", async (IMediator mediator, ProcessOrder cmd, CancellationToken ct) =>
{
    await mediator.Send("priority", cmd, ct);
    return Results.Accepted();
});

app.Run();

Default routing key

A null key (the default when no key is passed) is normalized internally to "__default". Avoid using that literal string as your own routing key.

NativeAOT

Keyed registration uses IKeyedServiceProvider internally and is not NativeAOT-compatible. Use it only when NativeAOT is not required.