Silverback

Silverback is a message bus and broker integration library for .NET. It helps you build event-driven architectures and asynchronous workflows with first-class support for Apache Kafka and MQTT.

Silverback aims to be both high-level (consistent configuration and developer experience) and broker-aware. Kafka is a first-class citizen: features like partition-based parallelism, keys/partitioning, tombstones, Schema Registry integration, idempotency, and transactions are surfaced where they matter, instead of being abstracted away.

Why Silverback

• Kafka-first, not Kafka-only – a consistent API across brokers, while still leveraging Kafka-specific capabilities.
• Reliable by design – transactional outbox, error policies, and storage-backed features.
• Operational usability – structured logging, diagnostics, and tracing.
• Built-in cross-cutting features – headers, validation, encryption, chunking, batching.
• Testability – in-memory broker mocks and end-to-end helpers.

Documentation, guides, and samples are available here: https://silverback-messaging.net

Project Status

Continuous Build

Sonar Build

Quality Metrics

Activity

Getting Started

Silverback is modular – reference only what you need.

Packages

Core:

• Silverback.Core – message bus and core messaging components.
• Silverback.Core.Model – message semantics for event-driven/CQRS scenarios.

Broker integration:

• Silverback.Integration.Kafka – Kafka support.
• Silverback.Integration.Mqtt – MQTT support.

Optional features:

• Silverback.Core.Rx – Rx.NET integration.
• Silverback.Newtonsoft – Newtonsoft.Json serialization.
• Silverback.Kafka.SchemaRegistry – Confluent Schema Registry integration.

Storage (for outbox, client-side offsets, distributed locks):

• Silverback.Storage.PostgreSql
• Silverback.Storage.Sqlite
• Silverback.Storage.EntityFramework
• Silverback.Storage.Memory

Testing:

• Silverback.Integration.Kafka.Testing
• Silverback.Integration.Mqtt.Testing

Supported .NET Versions

Starting with v5, Silverback targets the latest .NET LTS version only.

Quick Example (Kafka)

services.AddSilverback()
    .WithConnectionToMessageBroker(options => options.AddKafka())
    .AddKafkaClients(clients => clients
        .WithBootstrapServers("PLAINTEXT://localhost:9092")
        .AddProducer(producer => producer
            .Produce<MyMessage>(endpoint => endpoint.ProduceTo("my-topic")))
        .AddConsumer(consumer => consumer
            .Consume<MyMessage>(endpoint => endpoint.ConsumeFrom("my-topic"))));

Usage

See the docs site for guides, API reference, and runnable examples:

• https://silverback-messaging.net

Repository Solutions and Tools

Solutions

Solution	Contents
Silverback.sln	Library source projects, unit and E2E tests, and code/documentation generators
Silverback.Samples.sln	Runnable usage examples; see the samples guide
Silverback.Tests.Extended.sln	Interactive testbench, real-broker integration and stress tests, general benchmarks and version comparisons, with references to the library sources

Testing and Development Tools

Tool	Purpose
Interactive testbench	Windows WPF application for producing messages and managing Docker consumers
Integration tests	xUnit tests against real Kafka and MQTT brokers, including stress workloads and diagnostic controls
Benchmarks	General performance benchmarks and current-versus-historical Silverback comparisons
UpdateOlderVersions.ps1	Scaffold another historical benchmark project
coverage.ps1	Build and test the main solution with coverage, then generate and open an HTML report
docker-compose.yaml	Local Kafka, Schema Registry, MQTT and PostgreSQL infrastructure, with administration UIs
nuget/Update.ps1	Build local Silverback packages for package-based development and samples
.NET tool manifest	Repository-local ReportGenerator installation used by the coverage script

Code and Documentation Generators

The four generator applications are included in the main solution and write generated content to standard output. Shared generator support lives in Silverback.Tools.Generators.Common.

Tool	Purpose
KafkaConfigProxies	Generate Kafka configuration wrappers and builders; also supports Schema Registry configuration
MqttConfigProxies	Generate MQTT configuration wrappers and builders
Docs.Headers	Generate message-header reference tables
Docs.LogEvents	Generate log-event reference tables
docs/build.ps1	Build and serve the DocFX documentation locally; run from the docs directory
docs/publish.ps1	Publish the generated site through a separate gh-pages checkout; supports -NoPush

Build automation is defined in the main pipeline, the Sonar pipeline, and the samples/extended-tests pipeline.

Contributing

See CONTRIBUTING.md.

License

MIT License. See LICENSE.