What is RuleFlow?

RuleFlow is a lightweight, developer-friendly rule engine for .NET. You define rules with a fluent API, run them through IRuleEngine, and inspect outcomes—including explainability so you can see what ran, in what order, and why.

Why use it

• Small surface area: rules, rule sets, execution options—no ceremony
• Deterministic execution with priorities, optional groups, and stop rules
• Explainability built in: flat execution records, hierarchical trees, JSON and text formatters
• Debug DTO + JSON — ToDebugView() / ToDebugJson() for structured, UI-friendly execution output
• Async conditions and actions, runtime context, and optional JSON-backed definitions

Key features

Lightweight	Focused API; core types are easy to learn and test
Developer-friendly	Fluent Rule / RuleSet builders; familiar C# lambdas
Explainability	RuleResult with RuleExecution, ActionExecution, and formatters
Debug DTO + JSON	ToDebugView() and ToDebugJson() for structured, UI-friendly execution output
Observability	Optional metrics, custom observers, zero overhead when disabled

Documentation

Topic	Description
Getting started	Install, minimal example, run the playground
Rules	When, Then, ThenIf, Because, priority
Rule sets	RuleSet, groups, ordering
Explainability	RuleExecution, ActionExecution, debug string, debug DTO and JSON
Execution options	Stop on first match, filters, groups, explain toggle
Observability	Metrics, custom observers, performance monitoring
Persistence	RuleDefinition, registry, JSON definitions
Dynamic conditions	ConditionNode, operators, nested field paths
ASP.NET Core integration	AddRuleFlow() and DI

Versioning and NuGet

Versions follow SemVer tags: vMAJOR.MINOR.PATCH (for example v0.1.0). Pushing a tag triggers the publish workflow; set the NUGET_API_KEY secret in the repository.

GitHub Pages

In the repository settings, enable Pages: Deploy from a branch, branch main, folder /docs. This site is Markdown in docs/ with the default Jekyll integration.

Releases

See the full changelog on GitHub: https://github.com/rubenrichtering/RuleFlow/CHANGELOG.md

Source and playground

Examples in this documentation mirror the RuleFlow.ConsoleSample scenarios under samples/RuleFlow.ConsoleSample/Playground/Scenarios/.