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 rondorkerin/gamestack --skill animation-systemsgit clone --depth 1 https://github.com/rondorkerin/gamestackWrote 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/rondorkerin/gamestack/animation-systems)<a href="https://agentmods.dev/skills/rondorkerin/gamestack/animation-systems"><img src="https://agentmods.dev/badge/skills/rondorkerin/gamestack/animation-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/rondorkerin/gamestack/animation-systems"><img src="https://agentmods.dev/badge/skills/rondorkerin/gamestack/animation-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 | $0.00305 | $0.01292 |
| Opus 5 | $0.00152 | $0.00646 |
| Sonnet 5 | $0.00061 | $0.00258 |
| Haiku 4.5 | $0.00030 | $0.00129 |
Grade A, and why
animation-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 9d 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 — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Animation Systems
How to architect the motion system that makes a character or object move: the rig and skinning underneath, the blend/state machine/IK layer that composes authored motion, the procedural and physics-driven layer that makes it fit the world, the compression/cost model that ships it, and the timing decomposition that delivers correct anticipation and follow-through at scale.
Tier: technical craft (→
gamestack-core). Engine-agnostic motion-system architecture, the implementation layer under game-feel-and-juice's animation-timing principles.
When to use this
- Speccing a character motion system: rig, skinning method, blend architecture, IK, procedural/physics motion
- Choosing between authored state machines, blend spaces, and motion matching for a given motion space
- Making generated characters/creatures move plausibly from a finite hand-authored clip+rig library
- Diagnosing sliding/floating feet, a twisting mesh that pinches, popping or moonwalking blends, animation-locked controls, or a motion library over the memory budget
Scope
This skill owns the architecture of the motion system — rig, skinning, blending/state machines/IK, procedural and physics-driven motion, the compression/cost model, and the (anticipation, active, recovery) clip decomposition that delivers timing. Adjacent concerns live in sibling skills:
- The design rules for animation timing — the player-vs-enemy anticipation inversion, follow-through as weight-without-recovery-cost, squash/stretch, the 12 principles, the responsiveness ceiling →
game-feel-and-juice(this skill cites up to it and implements it) - Combat-specific application — telegraphing as fairness, hit-stop per damage tier, enemy/encounter feel →
combat-design - Pose silhouette, readability, signal color →
art-direction-and-readability - The rendering substrate for motion VFX (trails, dissolves, rim-light) →
shaders-and-vfx - Generated content/narrative coherence (vs generated motion) →
procedural-generation/procgen-review
What ships with it
2 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.
- 9d ago First seen · 43 lines · 305 tokens per session scan A 62f0112cd9bc
animation-systems is a skill published in the GitHub repository rondorkerin/gamestack (27 stars, last pushed 2mo ago), licensed MIT. It adds 305 tokens to every session and 1,292 once invoked, about $0.0015 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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asset-spec
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