Introduction

Invex.StructuredText is a family of strongly-typed C# libraries for generating structured YAML text files — specifically GitHub Actions workflows, Dependabot configurations, and Azure DevOps Pipelines — using a fluent, type-safe API with a unified expression system.

Why generate YAML from C#?

CI/CD configuration files grow quickly. Hand-written YAML suffers from:

• No compile-time validation — typos in keys, indentation mistakes, and invalid values are only discovered when the pipeline runs (or fails to parse).
• No refactoring support — renaming a job, output, or variable means find-and-replace across files and hoping you caught every reference.
• Duplication — YAML has limited reuse mechanisms, so common patterns get copy-pasted between workflows.
• Stringly-typed expressions — ${{ }} and $( ) expressions are opaque strings to your editor.

Invex.StructuredText solves these problems by letting you define your pipelines as C# object graphs:

• Full IntelliSense and compile-time validation for every property
• Models closely follow the official schemas (GitHub workflow schema, Dependabot v2 schema, Azure Pipelines YAML schema)
• A single, platform-agnostic expression system that compiles down to GitHub's ${{ }} syntax or Azure DevOps macro/runtime expression syntax
• Deterministic, cleanly formatted YAML output that is easy to diff and review

The packages

Package	What it provides
Invex.StructuredText	The core: StructuredTextWriter (indentation-aware text writer) and the TextExpression system
Invex.StructuredText.GithubActions	GithubActionWriter, DependabotConfigWriter, GithubExpressionFormatter, and full model types
Invex.StructuredText.AzureDevopsPipelines	DevopsPipelineWriter, DevopsExpressionFormatter, and full model types

Both platform packages depend on the core package, so installing either one gives you everything you need.

A taste

using Invex.StructuredText.GithubActions;
using Invex.StructuredText.GithubActions.GithubActionModel;

var workflow = new GithubAction
{
    Name = "CI",
    On =
    [
        new On.Push
        {
            Branches = ["main"],
            BranchesIgnore = null,
            Tags = null,
            TagsIgnore = null,
            Paths = null,
            PathsIgnore = null,
        },
    ],
    Jobs =
    [
        new Job
        {
            Name = new RawExpression("build"),
            RunsOn = new() { Labels = [new RawExpression("ubuntu-latest")] },
            Steps =
            [
                new Step.UsesStep { Uses = new RawExpression("actions/checkout@v4") },
                new Step.RunStep { Run = [new RawExpression("dotnet build -c Release")] },
            ],
        },
    ],
};

var writer = new GithubActionWriter();
writer.Write(workflow);

File.WriteAllText(".github/workflows/ci.yml", writer.TextWriter.ToString());

Where to go next

• Getting Started — install the packages and generate your first file
• Expressions — learn the unified expression system
• GitHub Actions — workflow generation in depth
• Dependabot — dependabot.yml generation
• Azure DevOps Pipelines — pipeline generation in depth
• Architecture — how the pieces fit together