MassTransit Documentation
MassTransit is an open-source distributed application framework for .NET that provides a consistent abstraction on top of supported message transports (RabbitMQ, Azure Service Bus, Amazon SQS, Kafka, ActiveMQ, SQL, and more). It simplifies building event-driven, message-based applications with consumers, sagas, state machines, routing slips, and the outbox pattern.
Documentation Structure
contents/ ├── 2.quick-starts/ # Transport-specific quick start guides (6 files) ├── 3.documentation/ │ ├── 1.concepts/ # Core messaging concepts (10 files) │ ├── 2.configuration/ # Full configuration reference (40 files) │ │ ├── 1.sagas/ # Saga configuration │ │ ├── 2.transports/ # Transport-specific config │ │ ├── 3.middleware/ # Middleware and filters │ │ ├── 4.persistence/ # Saga persistence backends │ │ ├── 6.topology/ # Broker topology │ │ ├── 7.routing-slips/ # Routing slip configuration │ │ └── integrations/ # SignalR, logging, NServiceBus, analyzers │ ├── 3.patterns/ # Messaging patterns (12 files) │ │ ├── 6.saga/ # Saga patterns and state machines │ │ └── 7.routing-slips/ # Routing slip patterns │ └── 6.transports/ # Transport reference docs (7 files) ├── 4.support/ # Upgrade guides and troubleshooting (5 files) └── samples/ # Complete working code samples (5 files)
Topic Guide
| Topic | Key Files |
|---|---|
| Getting started / setup | contents/2.quick-starts/1.in-memory.md, contents/3.documentation/2.configuration/0.index.md |
| Messages and contracts | contents/3.documentation/1.concepts/1.messages.md, contents/3.documentation/2.configuration/serialization.md |
| Consumers | contents/3.documentation/1.concepts/2.consumers.md, contents/3.documentation/2.configuration/1.consumers.md |
| Publishing and sending | contents/3.documentation/1.concepts/3.producers.md |
| Request / response | contents/3.documentation/1.concepts/6.requests.md |
| Exception handling and retry | contents/3.documentation/1.concepts/4.exceptions.md |
| Testing | contents/3.documentation/1.concepts/5.testing.md, contents/3.documentation/2.configuration/test-harness.md |
| Sagas and state machines | contents/3.documentation/3.patterns/6.saga/2.state-machine.md, contents/3.documentation/2.configuration/1.sagas/0.overview.md |
| Saga persistence | contents/3.documentation/2.configuration/4.persistence/entity-framework.md, contents/3.documentation/2.configuration/4.persistence/marten.md, contents/3.documentation/2.configuration/4.persistence/mongodb.md, contents/3.documentation/2.configuration/4.persistence/redis.md |
| RabbitMQ | contents/2.quick-starts/2.rabbitmq.md, contents/3.documentation/2.configuration/2.transports/2.rabbitmq.md, contents/3.documentation/6.transports/2.rabbitmq.md |
| Azure Service Bus | contents/2.quick-starts/3.azure-service-bus.md, contents/3.documentation/2.configuration/2.transports/3.azure-service-bus.md |
| Amazon SQS | contents/2.quick-starts/4.amazon-sqs.md, contents/3.documentation/2.configuration/2.transports/4.amazon-sqs.md |
| Kafka | contents/3.documentation/2.configuration/2.transports/10.kafka.md, contents/3.documentation/6.transports/kafka.md |
| SQL transport / PostgreSQL | contents/2.quick-starts/5.postgresql.md, contents/3.documentation/2.configuration/2.transports/6.sql.md |
| Outbox pattern | contents/3.documentation/3.patterns/10.in-memory-outbox.md, contents/3.documentation/3.patterns/11.transactional-outbox.md, contents/3.documentation/2.configuration/3.middleware/3.outbox.md |
| Job consumers | contents/3.documentation/3.patterns/13.job-consumers.md, contents/samples/job-consumer.md |
| Routing slips / Courier | contents/3.documentation/1.concepts/7.routing-slips.md, contents/3.documentation/2.configuration/7.routing-slips/0.overview.md |
| Middleware and filters | contents/3.documentation/2.configuration/3.middleware/0.index.md, contents/3.documentation/2.configuration/3.middleware/1.filters.md |
| Scheduling | contents/3.documentation/2.configuration/5.scheduling.md |
| Observability / OpenTelemetry | contents/3.documentation/2.configuration/observability.md |
| MultiBus | contents/3.documentation/2.configuration/multibus.md |
| Topology and broker configuration | contents/3.documentation/2.configuration/6.topology/0.index.md, contents/3.documentation/2.configuration/6.topology/deploy.md |
| Upgrading between versions | contents/4.support/4.upgrade.md |
| Troubleshooting | contents/4.support/common-mistakes.md, contents/4.support/show-configuration.md |
When to use
Use this skill when the user asks about:
- Setting up MassTransit with any transport (RabbitMQ, Azure Service Bus, Amazon SQS, Kafka, SQL)
- Defining and consuming messages in .NET
- Publishing and sending messages, request/response patterns
- Writing consumers, including fault consumers and exception handling
- Sagas, state machines, and stateful workflow patterns
- Saga persistence with Entity Framework, MongoDB, Redis, Marten, DynamoDB, etc.
- Outbox pattern (in-memory or transactional) for exactly-once delivery
- Routing slips and activity-based workflows (Courier)
- Job consumers for long-running background work
- Middleware, filters, and pipeline customization
- Message scheduling and delayed delivery
- Topology configuration and broker setup
- Testing MassTransit applications with the test harness
- Observability with OpenTelemetry
- Upgrading MassTransit versions
How to find information
- Use Topic Guide above to identify relevant files
- Read
TOC.mdfor complete file listing by directory - Read specific files from
contents/{path}
