API reference

This section is generated from the XML documentation comments in the source, so it always matches the shipped release.

Namespaces

Namespace	What lives there
Dispatcher	Message and handler contracts, dispatcher interfaces, Unit, DispatcherOptions, DispatcherTelemetryOptions, and the typed DI registration extensions
Dispatcher.DependencyInjection	The reflection-based Dispatcher implementation and its registration extensions

Frequently used types

Dispatching

• IDispatcher, IQueryDispatcher, ICommandDispatcher, INotificationDispatcher

Messages

• IMessage, IRequest, IQueryBase, ICommandBase
• IQuery<TResponse>, ICommand, ICommand<TResponse>, INotification

Handlers and pipeline

• IQueryHandler<,>, ICommandHandler<>, ICommandHandler<,>, INotificationHandler<>
• IPipelineBehavior<TRequest, TResponse>, RequestHandlerDelegate<TResponse>, Unit

Configuration

• ServiceCollectionExtensions, DispatcherOptions, DispatcherTelemetryOptions

Failures

Exception	Thrown when
HandlerNotFoundException	A query or command has no compatible handler
DuplicateHandlerException	Two handlers are registered for the same handled message type
AmbiguousHandlerException	Two unrelated equally specific candidate handlers match a message
UnsupportedHandlerException	A scanned type implements a handler contract in an unsupported shape
AssemblyScanException	An assembly cannot be scanned for handlers

Note

HandlerNotFoundException ships in Send0xx.Dispatcher and can be thrown by either implementation. The other exception types ship in Send0xx.Dispatcher.DependencyInjection; source generation reports their equivalent route and handler-shape failures as compiler diagnostics at build time.

What is not listed here

The GenerateDispatcher and GenerateDispatcherHandlers attributes do not appear in this reference. The source generator injects them into your own compilation as internal types rather than shipping them as public API, so there is no assembly for DocFX to read them from. The generated registration extension methods are likewise emitted into your project. Both are documented in Source generation.

Tip

Looking for how these types fit together rather than what they are? Start with Getting started.