Borrowing it
Nothing to install: this file belongs to MasterPlayspots/motionspec. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/MasterPlayspots/motionspec/main/AGENTS.mdgit clone --depth 1 https://github.com/MasterPlayspots/motionspecWrote 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/instructions/masterplayspots/motionspec/agents-md)<a href="https://agentmods.dev/instructions/masterplayspots/motionspec/agents-md"><img src="https://agentmods.dev/badge/instructions/masterplayspots/motionspec/agents-md/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/instructions/masterplayspots/motionspec/agents-md"><img src="https://agentmods.dev/badge/instructions/masterplayspots/motionspec/agents-md.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 | $0.02207 | $0.02207 |
| Opus 5.5 | $0.00883 | $0.00883 |
| Sonnet 5.5 | $0.00441 | $0.00441 |
| Haiku 4.5 | $0.00221 | $0.00221 |
Grade A, and why
motionspec AGENTS.md 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 18d 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 — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md — how a coding agent should use MotionSpec
This file is for AI coding agents (Claude Code, Cursor, Copilot, Codex, Cline, …) working in a repository that builds a web UI. It says what MotionSpec is, when to reach for it, which commands exist, and — just as important — what it does not check.
What MotionSpec is
MotionSpec is an MIT-licensed npm package (motionspec) with two parts:
- A deterministic motion compiler. You write a small JSON spec (
specVersion "1.0") that picks primitives from a fixed catalog of 40 (18 loops, 10 hover/press, 12 scroll). The compiler validates it fail-closed (45MS-*error codes) and emits vanilla-GSAP JavaScript plus CSS. Same spec → byte-identical output. Every build carries aprefers-reduced-motionguard, and every continuous loop gets a pause path (html[data-ms-paused]+animation-play-state: paused) by construction. - A static motion-accessibility audit of a live URL: it fetches the HTML and linked stylesheets and scans the CSS text. No headless browser.
It is not the Android MotionSpec class, not Motion.dev / Framer Motion, not usemotion.com,
and not a video generator.
When to use it
Use MotionSpec when you are about to add or change animation or transitions in a web UI — scroll reveals, parallax, hover effects, loaders, marquees, hero loops — or when you are asked whether a page's motion is accessible.
Do not use it as a general accessibility checker. Its scope is motion: WCAG 2.2.2 (Pause, Stop, Hide — Level A) and 2.3.3 (Animation from Interactions — Level AAA).
The rules an agent should follow, with or without MotionSpec
- Respect
prefers-reduced-motion. Every animation and transition you write must be disabled or reduced under@media (prefers-reduced-motion: reduce)(CSS) or behindmatchMedia('(prefers-reduced-motion: reduce)')(JS). This maps to WCAG 2.3.3 (AAA); it is a best practice, not a Level A fix. - Provide a pause for motion that starts automatically and runs longer than 5 seconds,
including
infiniteanimations (WCAG 2.2.2, Level A). Aprefers-reduced-motionguard alone does not satisfy 2.2.2 — the user needs a visible pause/stop control or an equivalent mechanism. - Never flash content more than 3 times per second (WCAG 2.3.1, Level A). MotionSpec does not audit flashing — you have to check this yourself.
- Animate
transformandopacity, not layout properties (width,top,background…). - Prefer the catalog primitive over hand-written keyframes when one exists; if none fits, write CSS/JS by hand and still apply rules 1–4.
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.
- 18d ago Changed · +12 lines · +282 tokens per session 5d5902324e2a
- 1mo ago First seen · 137 lines · 1,925 tokens per session scan A cd9d376066fb
motionspec AGENTS.md is an instructions file published in the GitHub repository MasterPlayspots/motionspec (1 stars, last pushed yesterday), licensed MIT. It adds 2,207 tokens to every session, about $0.0088 per session on Opus 5.5. 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 2026-09-08.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.