unity-ecs

A Unity guide for deciding whether to use ECS, Jobs, or Burst, which are Unity tools for processing large amounts of game data efficiently. It also explains mixed designs and gradual migration from MonoBehaviour code.

In plain words
What is it for?
Use it when evaluating ECS or DOTS, handling thousands of entities, using Jobs or Burst, managing native memory, or moving an existing MonoBehaviour system toward ECS.
Why use it?
It helps developers judge whether data-oriented tools will solve a real performance problem or add unnecessary complexity.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/thearcforge/hades/unity-ecs
Any agent
npx skills add TheArcForge/Hades --skill unity-ecs
Clone the repo
git clone --depth 1 https://github.com/TheArcForge/Hades

Made for: Claude Code, Codex.

Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,930 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00034 $0.05930
Opus 5 $0.00017 $0.02965
Sonnet 5 $0.00007 $0.01186
Haiku 4.5 $0.00003 $0.00593

Measured 2d ago against content hash d77a537cec8f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

unity-ecs scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

ClaudeCodePlugin/skills/unity-ecs/SKILL.md · 694 lines

How it starts

The opening of the file, as written. The whole thing — 694 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Unity ECS / DOTS

Decision framework for adopting Unity's Data-Oriented Technology Stack. Covers when ECS, Jobs, and Burst deliver meaningful value vs. when they add cost without benefit, how to apply each layer independently, and a proven incremental migration path from MonoBehaviour to full ECS.

When to Apply

Activate when the conversation involves:

  • Evaluating whether to use ECS, Jobs, or Burst for a new system
  • A MonoBehaviour simulation that is hitting CPU performance limits
  • Questions about IComponentData, SystemBase, ISystem, IJobParallelFor, or BurstCompile
  • Deciding on a hybrid approach (MonoBehaviour logic driving entity data via Baking)
  • Migrating an existing MonoBehaviour-based system toward DOTS
  • Any mention of entity counts in the thousands or tens of thousands
  • NativeContainer allocation or disposal questions

Do NOT activate for general performance questions not involving entities — those go to hades:unity-performance. Do NOT activate for architecture questions about scene or prefab structure — those go to hades:unity-architect.

Project Context Check

Before making ECS recommendations, gather context so advice matches the actual project state.

  1. Check for existing ECS usage:

    • Call graph_query(edgeKind: "references", edgeTargetNamePattern: "IComponentData", edgeTargetKind: "Class") — reveals whether ECS components already exist. If they do, advice must be consistent with those patterns.
    • Call graph_query(edgeKind: "references", edgeTargetNamePattern: "SystemBase", edgeTargetKind: "Class") and the same with edgeTargetNamePattern: "ISystem" — identifies existing ECS systems. Presence of ISystem (unmanaged) suggests a performance-first stance; SystemBase suggests an earlier adoption or more managed-style code.
  2. Understand project scale and targets:

    • Call get_project_summary() — reveals platform targets (mobile vs. PC/console), project age, and team size. ECS has a steep learning curve; on a solo mobile project with a 6-month timeline, it is rarely appropriate.

Read the full file on GitHub · 694 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 694 lines · 34 tokens per session scan A d77a537cec8f

Subscribe to this mod's changes

unity-ecs is a skill published in the GitHub repository TheArcForge/Hades (27 stars, last pushed 6d ago), licensed MIT. It adds 34 tokens to every session and 5,930 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories