Introduction

Atom is a build automation framework for .NET that lets you define your entire build pipeline in C#. Instead of maintaining separate YAML or script files, you write strongly-typed build logic alongside your application code, gaining full IDE support — IntelliSense, refactoring, and step-through debugging.

Key Concepts

Concept	Description
Build Definition	A C# class that declares your targets, parameters, and build configuration.
Target	A named unit of work (compile, test, pack, deploy, etc.) with optional dependencies on other targets.
Parameter	A value that can be supplied via the command line, environment variable, appsettings.json, or a secrets provider.
Module	A NuGet package that adds reusable targets, parameters, or service registrations to your build.
Workflow	An optional layer that maps targets to CI/CD jobs and generates platform-specific YAML (GitHub Actions, Azure DevOps).

Package Overview

Atom is split into several NuGet packages so you only pull in what you need:

Package	Purpose
Invex.Atom.Build	Core framework — build definitions, targets, parameters, hosting.
Invex.Atom.Workflows	Workflow definitions, triggers, and YAML generation.
Invex.Atom.Module.*	First-party modules (Dotnet, GitVersion, AzureKeyVault, etc.).
Invex.Atom.Tool	The atom .NET global tool for running builds from the command line.

Foundational Libraries

Several lower-level building blocks live in their own repositories and are published as standalone packages. You don't normally reference these directly — they are pulled in transitively by Invex.Atom.Build — but their types surface through Atom (for example via IBuildAccessor.RootedFileSystem and IBuildAccessor.ProcessRunner):

Package	Purpose
Invex.FileSystem	IRootedFileSystem, RootedPath, path providers, and file transformations.
Invex.Process	IProcessRunner for executing external tools.
Invex.SemanticVersion	Semantic versioning utilities.
Invex.StructuredText	Structured text / YAML writing used by the workflow generators.

How It Works

1. You create a C# project (or a single .cs file) that references the Atom packages.
2. You define a class decorated with [BuildDefinition] that inherits from BuildDefinition (or WorkflowBuildDefinition if you need CI/CD generation).
3. Inside that class you declare targets — lambda-based definitions that describe what to execute, their dependencies, required parameters, and produced artifacts.
4. You run the build with dotnet run -- <TargetName> (or via the atom global tool).
5. If you use WorkflowBuildDefinition, running the Gen target emits platform-specific YAML that invokes your same build on CI.

Next Steps

→ Your First Build