Inlet Reference

Overview

Inlet is the Mississippi composition and source-generation layer. For the relationship between domain metadata, generated types, and host registrations, see Generated Application Contracts.

Applies To

• Mississippi.Inlet.Abstractions
• Mississippi.Inlet.Client
• Mississippi.Inlet.Gateway
• Mississippi.Inlet.Runtime

Verified Client Registration Surface

These client-side Inlet extensions compose on IReservoirBuilder. Full Mississippi client apps reach them through ClientBuilder.Reservoir(...).

Method	Receiver	Purpose
AddInletClient()	IReservoirBuilder	Register the client projection registry, ProjectionsFeatureState, IInletStore, and IProjectionUpdateNotifier
AddProjectionPath<T>(path)	IReservoirBuilder	Add an explicit projection-path mapping
AddInletBlazor()	IReservoirBuilder	Add the Blazor-specific registration extension point
AddInletBlazorSignalR(...)	IReservoirBuilder	Configure SignalR-driven projection refresh
AddSignalRConnectionFeature()	IReservoirBuilder	Register the SignalR connection state feature

Source code:

• InletClientRegistrations.cs
• InletBlazorRegistrations.cs
• SignalRConnectionRegistrations.cs

InletBlazorSignalRBuilder

AddInletBlazorSignalR(...) configures a dedicated InletBlazorSignalRBuilder.

Configure it inside that callback. Once its registrations are built, further configuration or another build attempt throws InvalidOperationException; a read-only parent service collection also prevents configuration. This keeps deferred projection factories bound to the configuration that was registered.

Member	Purpose
AddProjectionFetcher<TFetcher>()	Use a custom IProjectionFetcher implementation
ScanProjectionDtos(params Assembly[] assemblies)	Enable automatic projection DTO discovery and the auto fetcher
WithHubPath(hubPath)	Set the SignalR hub path
WithRoutePrefix(prefix)	Set the HTTP projection route prefix used by the auto fetcher

AddInletBlazorSignalR(...) also adds the SignalR connection feature automatically during Build().

Source code:

• InletBlazorSignalRBuilder.cs

Generated Client Method Shapes

The current Inlet client generators emit builder-based client registrations.

Generator	Generated method shape	Receiver
Command client generator	Add{Aggregate}AggregateFeature()	IReservoirBuilder
Saga client generator	Add{Saga}SagaFeature()	IReservoirBuilder
Projection client generator	AddProjectionsFeature()	IReservoirBuilder
Domain client generator	Add{Domain}Client()	ClientBuilder

Source code:

• CommandClientRegistrationGenerator.cs
• SagaClientRegistrationGenerator.cs
• ProjectionClientRegistrationGenerator.cs
• DomainClientRegistrationGenerator.cs

Verified Ownership Boundary

• Shared abstractions for projection paths and related metadata
• Client support for projection state and subscriptions
• Gateway support for generated APIs and SignalR delivery
• Runtime support for discovery and generated registrations
• Source generators that align those layers

Related But Separate Areas

• Aqueduct owns the real-time backplane.
• Reservoir owns the client-state model.
• Domain Modeling owns domain behavior.

Defaults And Constraints

This reference covers the verified subsystem boundary and the current client-side builder surface. Inlet client registrations assume a Reservoir builder exists; full Mississippi client apps create that builder by starting with UseMississippi(...) and then using Reservoir(...).

Failure Behavior

Client terminal attachment uses BuilderValidationException with stable diagnostic codes and remediation text. See Client Composition for the attachment contract and failure behavior.

For generator and runtime registration failure behavior, refer to the Inlet Operations page. Generator misalignment typically surfaces at compile time.

Summary

Use this page as the current active reference for Inlet's builder-based client registrations and the generated client method shapes that compose through ClientBuilder and IReservoirBuilder.

Next Steps

• Read Inlet Concepts.
• Read How To Compose Inlet In Mississippi Client Apps for startup composition guidance.
• Use the Spring Sample to see Inlet composition patterns in practice.