LevelUp.Strategos.Ontology 3.0.0

Strategos.Ontology

Type-safe ontology definition layer for domain modeling. Map your existing C# types into a unified semantic graph of Object Types, Properties, Links, Actions, Events, and Interfaces — validated at compile time, queryable at runtime.

Installation

dotnet add package LevelUp.Strategos.Ontology
dotnet add package LevelUp.Strategos.Ontology.Generators

Quick Start

using Strategos.Ontology;

public class TradingOntology : DomainOntology
{
    public override string DomainName => "trading";

    protected override void Define(IOntologyBuilder builder)
    {
        builder.Object<Position>(obj =>
        {
            obj.Key(p => p.Id);
            obj.Kind(ObjectKind.Entity);
            obj.Property(p => p.Symbol).Required();
            obj.Property(p => p.UnrealizedPnL).Computed()
               .DerivedFrom(p => p.Quantity, p => p.AverageCost);

            obj.HasMany<TradeOrder>("Orders").Inverse("Position");

            obj.Action("ExecuteTrade")
               .Requires(p => p.Status == PositionStatus.Active)
               .RequiresSoft(p => p.UnrealizedPnL > -10000)
               .Modifies(p => p.Quantity)
               .CreatesLinked<TradeOrder>("Orders");

            obj.Lifecycle<PositionStatus>(p => p.Status, lc =>
            {
                lc.State(PositionStatus.Pending).Initial();
                lc.State(PositionStatus.Active);
                lc.State(PositionStatus.Closed).Terminal();
                lc.Transition(PositionStatus.Pending, PositionStatus.Active)
                  .TriggeredByAction("Activate");
            });
        });
    }
}

Registration

services.AddOntology(options =>
{
    options.AddDomain<TradingOntology>();
    options.UseObjectSetProvider<MyObjectSetProvider>();
    options.UseActionDispatcher<MyActionDispatcher>();
});

Runtime Queries

Inject IOntologyQuery to query the ontology at runtime:

// Which actions are valid given current state?
var facts = new ActionFacts(
    properties:
    [
        KeyValuePair.Create(
            "Status",
            PredicateLiteral.Enum("PositionStatus", "Active")),
    ]);
var candidates = query.GetCandidateActions("trading", "Position", facts);

// Structured constraint report with failure reasons
var report = query.GetActionConstraintReport("trading", "Position", facts);

// What would ExecuteTrade affect?
var effects = query.TracePostconditions("Position", "ExecuteTrade");

// Derivation impact analysis
var affected = query.GetAffectedProperties("Position", "Quantity");

Features

• Fluent DSL: Expression-tree-based builder for type-safe ontology definitions
• Compile-Time Validation: Roslyn AONT diagnostics catch authoring and contract errors at build time
• Object Types: Map existing C# types with keys, properties, links, actions, events
• IS-A Hierarchy: IsA<TParent>() for type subsumption and inheritance queries
• Typed action contracts: Closed hard/soft predicates, explicit guarantees, exact sequential composition proofs, and tri-state runtime discovery
• Lifecycle: State machine declarations with action/event-triggered transitions
• Derivation Chains: Transitive property dependency tracking across domains
• Interfaces: Polymorphic queries across domain boundaries
• Extension Points: Controlled cross-domain link attachment
• Inverse Links: Bidirectional traversal with symmetry validation

Documentation

• Platform Architecture — Ontology Layer
• API Reference

License

MIT