Prerequisites & Installation

Modulus is a .NET global tool that scaffolds production-ready modular monolith solutions. This page covers everything you need to install and start using the CLI.

Prerequisites

.NET 10 SDK

The ModulusKit.Cli tool and every scaffolded solution require the .NET 10 SDK to run the CLI and build generated solutions. You need the SDK installed even if your own application targets an older LTS — the tool itself always runs on .NET 10.

Download .NET 10 SDK

Verify your installation:

dotnet --version
# 10.0.100 or later

Library packages also support .NET 8

The seven ModulusKit.* runtime library packages (Mediator, Mediator.Abstractions, Messaging, Messaging.Abstractions, Messaging.RabbitMq, Messaging.AzureServiceBus, Testing) multi-target net8.0;net10.0, so you can reference them from a .NET 8 LTS project. The CLI tool and its scaffolded solution templates remain .NET 10-only.

Docker (optional)

The generated solution includes integration tests powered by Testcontainers. If you plan to run integration tests locally, you need Docker Desktop or a compatible container runtime.

Not required for getting started

Docker is only needed for integration tests. You can scaffold solutions, build, and run unit tests without it.

Installation

Install the Modulus CLI as a .NET global tool:

dotnet tool install --global ModulusKit.Cli

Verify Installation

After installation, confirm the CLI is available:

modulus version

This outputs the installed version of Modulus. If you receive a "command not found" error, ensure that the .NET global tools directory is on your PATH.

.NET global tools path

The default global tools directory is:

• Windows: %USERPROFILE%\.dotnet\tools
• macOS / Linux: $HOME/.dotnet/tools

Add the appropriate path to your shell profile if it is not already present.

Update

To update to the latest version:

dotnet tool update --global ModulusKit.Cli

Uninstall

To remove Modulus:

dotnet tool uninstall --global ModulusKit.Cli

NuGet Packages

Modulus ships as a CLI tool plus a set of companion library packages. The CLI automatically references the correct packages when scaffolding a solution, so you do not need to install them manually.

Package	Description
ModulusKit.Cli	CLI tool for scaffolding modular monolith solutions
ModulusKit.Mediator	CQRS mediator with pipeline behaviors and Result pattern
ModulusKit.Mediator.Abstractions	Mediator interfaces, Result types, and pipeline contracts
ModulusKit.Messaging	Messaging core with in-memory transport, transactional outbox, and inbox
ModulusKit.Messaging.RabbitMq	RabbitMQ transport for ModulusKit.Messaging
ModulusKit.Messaging.AzureServiceBus	Azure Service Bus transport for ModulusKit.Messaging
ModulusKit.Messaging.Abstractions	Messaging interfaces and integration event contracts
ModulusKit.Generators	Roslyn source generators for handler registration and module discovery
ModulusKit.Analyzers	Roslyn analyzers enforcing modular architecture (MOD001–MOD005)
ModulusKit.Testing	Test harness, in-memory test transport, and outbox/inbox assertion helpers

Abstractions packages

The Abstractions packages contain only interfaces and contracts with zero third-party dependencies. Reference them in your Domain and Application layers to keep those layers clean. The implementation packages (ModulusKit.Mediator and ModulusKit.Messaging) are referenced only in Infrastructure and host projects.

What's Next

Now that Modulus is installed, walk through the end-to-end tutorial to create your first modular monolith solution.

Your First Solution