Guidance for building interfaces with coss UI, a library of reusable controls such as buttons, dialogs, forms, menus, and tabs.

Use it to choose and combine coss components, build common interface patterns, or troubleshoot their behavior.

It helps avoid incorrect imports, inaccessible controls, and composition mistakes when using coss or moving from similar UI libraries.

coss — Skill for Claude Code and Codex by usekaneo: Guidance for building interfaces with coss UI, a library…

About the project

Kaneo is an open-source project-management application for organizing work with kanban boards, issues, and issue tracking. Teams use it to manage projects, and its self-hosted design lets them keep the application and data under their control. The catalogue contains skills, rules, instructions, and an MCP integration for working with Kaneo.

usekaneo/kaneo · 8,954 stars · on GitHub · kaneo.app

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/usekaneo/kaneo/coss

Any agent

npx skills add usekaneo/kaneo --skill coss

Clone the repo

git clone --depth 1 https://github.com/usekaneo/kaneo

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/usekaneo/kaneo/coss.svg)](https://agentmods.dev/skills/usekaneo/kaneo/coss)

Your own site

<a href="https://agentmods.dev/skills/usekaneo/kaneo/coss"><img src="https://agentmods.dev/badge/skills/usekaneo/kaneo/coss.svg" alt="Measured on agentmods" height="20"></a>

Per session 80 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,176 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.

Model	Per session	Once invoked
Fable 5.1	$0.00080	$0.01176
Opus 5	$0.00040	$0.00588
Sonnet 5	$0.00016	$0.00235
Haiku 4.5	$0.00008	$0.00118

Measured 6d ago against content hash 693a15960cbc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

coss 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 6d 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

2 near-identical copies found in the catalogue:

coss — 95% identical, 2 lines differ
coss — 95% identical, 1 lines differ

.agents/skills/coss/SKILL.md · 117 lines

How it starts

The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.

coss ui

coss ui is a component library built on Base UI with a shadcn-like developer experience plus a large particle catalog.

What this skill is for

Use this skill to:

pick the right coss primitive(s) for a UI task
write correct coss usage code (imports, composition, props)
avoid common migration mistakes from shadcn/Radix assumptions
reference particle examples to produce practical, production-like patterns

Source of truth

coss components docs: apps/ui/content/docs/components/*.mdx
- https://github.com/cosscom/coss/tree/main/apps/ui/content/docs/components
coss particle examples: apps/ui/registry/default/particles/p-*.tsx
- https://github.com/cosscom/coss/tree/main/apps/ui/registry/default/particles
coss particles catalog: https://coss.com/ui/particles
docs map for agents: https://coss.com/ui/llms.txt

Out of scope

Maintaining coss monorepo internals/build pipelines.
Editing registry internals unless explicitly requested.

Principles for agent output

Use existing primitives and particles first before inventing custom markup.
Prefer composition over custom behavior reimplementation.
Follow coss naming and APIs from docs exactly.
Keep examples accessible and production-realistic.
Prefer concise code that mirrors coss docs/particles conventions.
Assume Tailwind CSS v4 conventions in coss examples and setup guidance.

Critical usage rules

Always apply before returning coss code:

Do not invent coss APIs. Verify against component docs first.
For trigger-based primitives (Dialog, Menu, Select, Popover, Tooltip), follow each primitive's documented trigger/content hierarchy and composition API; do not mix patterns across components.
Preserve accessibility labels and error semantics.
Consult primitive-specific guides for component invariants and edge cases.
For manual install guidance, include all required dependencies and local component files referenced by imports.
Prefer styled coss exports first; use *Primitive exports only when custom composition/styling requires it.

Read the full file on GitHub · 117 lines

Files

What ships with it

59 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.

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.

6d ago First seen · 117 lines · 80 tokens per session scan A 693a15960cbc

Subscribe to this mod's changes

coss is a skill published in the GitHub repository usekaneo/kaneo (8,954 stars, last pushed yesterday), licensed MIT. It adds 80 tokens to every session and 1,176 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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