Inbox InMemory Transport Dispatch

ID: dispatch.inbox.inmemory
Name: Inbox InMemory transport dispatch
Maturity: GA
Summary: Publish leased inbox envelopes through in-process channels for tests and local multi-service pipelines without external brokers.

What It Does

AddInMemoryTransport() registers InMemoryTransportModule at the root, and UseInMemoryDispatch registers TransportInboxDispatchModule as its inbox feature bridge. Messages flow through System.Threading.Channels to a logical destination name. This path is used heavily in integration tests to simulate remote dispatch and pair with InMemory ingress.

Packages

Package	Role
`LiteBus.Inbox.Dispatch.InMemory`	Registration glue
`LiteBus.Inbox.Dispatch`	Shared dispatcher
`LiteBus.Transport.InMemory`	Channel-based transport

Requires

dispatch.transport-core
transport.inmemory
durable-core.inbox

Invariants

Thread-safe within one process; not cross-process.
Requeue on failed consume re-enqueues on the channel (transport invoker).
Same header mapping as broker transports.

Non-Goals

Not for production cross-host messaging.
Does not survive process restarts.

Public Surface

services.AddLiteBus(litebus =>
{
    litebus.AddInMemoryTransport();

    litebus.AddInbox(inbox =>
    {
        inbox.EnableInboxProcessor();
        inbox.UseInMemoryDispatch(options =>
        {
            options.DefaultDestination = "orders.commands";
        });
    });
});

API	Role
`InboxModuleBuilder.UseInMemoryDispatch(Action<TransportInboxDispatcherOptions>? configure = null)`	Registers inbox transport dispatcher that requires the root in-memory transport
`TransportInboxDispatcher.DispatchAsync(InboxEnvelope, CancellationToken)`	Shared publish logic over in-process channel transport

Observability

Signal	Detail
`send {destination}`	Emitted by `InMemoryPublisher` with destination and route tags
`process {destination}`	Paired ingress/consumer in the same process
`litebus.transport.circuit_breaker.*`	Tag `inmemory`; standalone breaker registered by InMemory transport
`litebus.inbox.processor.*`	Standard processor metrics

Activities remain available for test assertions even without external OTLP export.

Deep Docs

Integration-Tests.md

Test Coverage

Covered

Test method	Project
`InboxDispatchExtensions_ShouldRegisterTransportDispatcher`	`LiteBus.Durable.IntegrationTests` (`Registration/`)
`ProcessPendingAsync_ShouldPublishLeasedEnvelopeToInMemoryDestination`	`LiteBus.Durable.IntegrationTests` (`Dispatch/Inbox/InMemory/`)
`ProcessPendingAsync_WhenPersistSkippedAfterDispatch_ShouldRedispatchOnRetry`	`LiteBus.Durable.IntegrationTests` (`Dispatch/Inbox/InMemory/`)

Untested

Inbox dispatch failure and retry path beyond persist-skipped scenario.
Custom route resolver and tenant route strategy branches.
Cross-process delivery, which the in-memory adapter does not support.

Out-of-Scope

Production cross-host messaging
Surviving process restarts