petdex: Skill for Claude Code

.agents/skills/coss-particles/SKILL.md

coss-particles is a skill for Claude Code, Codex from crafter-station/petdex. It costs 46 tokens per session (12,105 once invoked), scanned A, original, MIT.

A searchable catalogue of 484 copy-and-paste UI patterns built from COSS interface components. It includes examples such as forms, dialogs, tabs, buttons, calendars, and other common interface parts.

In plain words
What is it for?
It is for locating and adapting ready-made UI code for features such as forms with validation, dialogs, tabs, and other web interface components.
Why use it?
It helps developers find an existing interface pattern instead of designing and coding one from scratch. Each pattern has a description and a URL for its source code.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is crafter-station/petdex's own configuration. It tells Claude Code and Codex how to work on petdex itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything petdex configures →

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is node apps/ui/scripts/generate-particle-index.cjs.

About the project

Petdex is a gallery, installer, and desktop application for animated pets that accompany coding agents. People browse and submit pets through its website, install them with a command-line tool, and use the desktop app to display reactions to agent activity. The catalogue includes skills and instructions for creating or using these pets with supported coding agents.

crafter-station/petdex · 4,052 stars · on GitHub · petdex.dev

Reuse

Borrowing it

Nothing to install: this file belongs to crafter-station/petdex. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/crafter-station/petdex/main/.agents/skills/coss-particles/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/crafter-station/petdex

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for coss-particles

README.md
[![agentmods](https://agentmods.dev/badge/skills/crafter-station/petdex/coss-particles/github.svg)](https://agentmods.dev/skills/crafter-station/petdex/coss-particles)
Your own site
<a href="https://agentmods.dev/skills/crafter-station/petdex/coss-particles"><img src="https://agentmods.dev/badge/skills/crafter-station/petdex/coss-particles/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.

agentmods 80×15 button for coss-particles

Your own site · 80×15
<a href="https://agentmods.dev/skills/crafter-station/petdex/coss-particles"><img src="https://agentmods.dev/badge/skills/crafter-station/petdex/coss-particles.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 12,105 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00046 $0.12105
Opus 5 $0.00023 $0.06052
Sonnet 5 $0.00009 $0.02421
Haiku 4.5 $0.00005 $0.01210

Measured 9d ago against content hash 742bad15e56a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

coss-particles 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.agents/skills/coss-particles/SKILL.md · 738 lines

How it starts

The opening of the file, as written. The whole thing — 738 lines — stays where its author put it; the contents beside it link to each section on GitHub.

COSS UI Particles Index

Particles are copy-paste-ready UI patterns built on coss primitives. Browse them visually at https://coss.com/ui/particles.

How to use this skill

  1. Describe the UI you need (e.g. "a form with validation", "a dialog with a form inside", "tabs with icons").
  2. Search this index for matching particles by component type and description.
  3. Fetch the JSON URL to get the full source code of the particle.
  4. Adapt the particle code to your needs.

JSON URL pattern

Each particle has a JSON manifest at:

https://coss.com/ui/r/<particle-name>.json

For example: https://coss.com/ui/r/p-accordion-1.json

Source code

Particle source files live in this repo at apps/ui/registry/default/particles/.

Updating this index

Run the generator script from the coss repo root:

node apps/ui/scripts/generate-particle-index.cjs

Total: 484 particles across 52 component types

Component types

Read the full file on GitHub · 738 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. 9d ago First seen · 738 lines · 46 tokens per session scan A 742bad15e56a

Subscribe to this mod's changes

coss-particles is a skill published in the GitHub repository crafter-station/petdex (4,052 stars, last pushed yesterday), licensed MIT. It adds 46 tokens to every session and 12,105 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.

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