Obsolete Methods

MassTransit retains a lot of older methods to avoid breaking builds when upgrading to new versions. While these methods should still work as they did previously, they don't represent the current usage guidelines.

Since obsolete method warnings can be ignored, they have been added to many methods that are completely usable but not recommended.


The UseRetry middleware method was replaced by UseMessageRetry. The only scenario where the previous method should be used is in specific message pipelines where retry within the same consumer or saga context is preferred.

Consumer Definitions

The ConfigureConsumer, ConfigureSaga, ConfigureExecuteActivity, and ConfigureCompensateActivity methods in consumer, saga, and activity definitions have a new overload that adds the IRegistrationContext parameter.

The IRegistrationContext interface implements IServiceProvider as well, so there is no need to inject it into the constructor.

The IRegistrationContext argument should be passed to methods that accept it, or that may have previously accepted IServiceProvider, to ensure the correct context is used for the bus and to ensure message scope is properly handled.

For example, the outbox now requires IRegistrationContext as an argument.

protected override void ConfigureSaga(IReceiveEndpointConfigurator configurator, 
    ISagaConfigurator<JobAttemptSaga> sagaConfigurator,
    IRegistrationContext context)
    configurator.UseMessageRetry(r => r.Intervals(100, 1000, 2000, 5000));

    // use the new overload, not the obsolete one


The original test harness has been deprecated, use AddMassTransitTestHarness instead. The current test harness is covered in the Testing documentation. Additional methods including AddConsumerTestHarness, AddSagaTestHarness, and AddSagaStateMachineTestHarness are not used with the new test harness.


Transports have their own UsingXxx methods, such as UsingRabbitMq. To ensure the container and all supporting bus components are properly configured, the UsingXxx methods should be used.

Instance, Data (Saga State Machines)

The Automatonymous properties Instance and Data have been superseded by Saga and Message to be consistent with MassTransit terminology.

Job Service Configuration

The job service configuration was drastically simplified in v8.1 - eliminating the need to configure the service instance. See the updated documentation for details.