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.
npx skills add tomkrikorian/visionOSAgents --skill realitykit-ecs-systemsgit clone --depth 1 https://github.com/tomkrikorian/visionOSAgentsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/tomkrikorian/visionosagents/realitykit-ecs-systems)<a href="https://agentmods.dev/skills/tomkrikorian/visionosagents/realitykit-ecs-systems"><img src="https://agentmods.dev/badge/skills/tomkrikorian/visionosagents/realitykit-ecs-systems/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/tomkrikorian/visionosagents/realitykit-ecs-systems"><img src="https://agentmods.dev/badge/skills/tomkrikorian/visionosagents/realitykit-ecs-systems.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00083 | $0.00583 |
| Opus 5 | $0.00042 | $0.00292 |
| Sonnet 5 | $0.00017 | $0.00117 |
| Haiku 4.5 | $0.00008 | $0.00058 |
Grade A, and why
realitykit-ecs-systems 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 11d 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.
How it starts
The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
RealityKit ECS Systems
Quick Start
- First verify that a documented RealityKit component cannot solve the
problem; use
realitykit-visionos-developercomponent selection when unsure. - Use a custom
Componentfor per-entity state and a customSystemfor continuous or multi-entity behavior. - Register custom components and systems once during app startup before any scene, asset, or Reality Composer Pro content that depends on them loads.
- Keep per-frame work in systems, not SwiftUI body code or ad hoc timers.
- Load the full ECS guide only when implementing or debugging real custom ECS code.
Load References When
| Reference | When to Use |
|---|---|
references/systemandcomponentcreation.md |
Implement a complete custom component/system registration, query, and update-order pattern. |
references/custom-components.md |
Define custom per-entity data and registration behavior. |
references/custom-systems.md |
Implement custom systems, queries, per-frame behavior, and update loops. |
Cross-Routing
- Use
realitykit-visionos-developerfor general component choice, entity loading, input, attachments, anchoring, portals, sync, and localUSDStageComponent. - Use
realitykit-rendering-materialswhen custom ECS only exists to drive materials, lights, post-processing, LOD, splats, or other visual state. - Use
realitykit-animation-physicswhen custom ECS interacts with animation, character motion, navigation, collision, physics, particles, or cloth. - Use
realitykit-audio-spatialwhen systems coordinate entity-owned audio.
Guardrails
- Prefer documented components before custom ECS.
- Register before loading scenes that reference the custom types.
- Keep system queries narrow and update only the entities that need work.
- Do not store SwiftUI-only state in RealityKit components unless entity ownership is intentional.
- Summarize registration order and query shape when changing ECS code.
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 11d ago First seen · 58 lines · 83 tokens per session scan A 24129eb2d197
realitykit-ecs-systems is a skill published in the GitHub repository tomkrikorian/visionOSAgents (61 stars, last pushed 2mo ago), licensed MIT. It adds 83 tokens to every session and 583 once invoked, about $0.0004 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.
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