1---2name: jecs3description: Use when building ECS-based games in Roblox with roblox-ts using jecs for entities, components, queries, and relationships4---56> Based on jecs v0.9.0, generated 2026-01-2978High-performance Entity Component System for Luau/roblox-ts. Features entity9relationships, archetype storage, 800k entities at 60fps.1011## Core References1213| Topic | Description | Reference |14| ---------------- | ------------------------------------------------------ | ------------------------------------------ |15| World & Entities | World creation, entities, components, tags, singletons | [core-basics](references/core-basics.md) |16| Queries | Query system, filters (with/without), caching | [core-queries](references/core-queries.md) |1718## Features1920| Topic | Description | Reference |21| --------------------- | ------------------------------------------------------ | -------------------------------------------------------------- |22| Pairs & Relationships | Entity pairs, ChildOf, wildcards, relationship queries | [feature-pairs](references/feature-pairs.md) |23| Component Hooks | OnAdd, OnChange, OnRemove lifecycle hooks | [feature-hooks](references/feature-hooks.md) |24| Signals | Multiple listeners with added/changed/removed signals | [feature-signals](references/feature-signals.md) |25| Cleanup Traits | OnDelete, OnDeleteTarget, cascade deletion policies | [feature-cleanup-traits](references/feature-cleanup-traits.md) |2627## Best Practices2829| Topic | Description | Reference |30| --------------- | ------------------------------------------------- | ------------------------------------------------------------------------------ |31| Archetypes | Archetype storage, transitions, fragmentation | [best-practices-archetypes](references/best-practices-archetypes.md) |32| Change Tracking | Delta detection, dirty flags, networking patterns | [best-practices-change-tracking](references/best-practices-change-tracking.md) |3334## Advanced3536| Topic | Description | Reference |37| ------------ | ------------------------------------------- | ------------------------------------------ |38| Advanced API | Preregistration, bulk ops, TypeScript types | [advanced-api](references/advanced-api.md) |