gem-designer

gem-designer is an agent for Claude Code from github/awesome-copilot. It costs 22 tokens per session (908 once invoked), scanned A, original, MIT.

A UI and UX design specialist that plans page layouts, visual themes, color schemes, design systems, accessibility, and responsive behavior.

In plain words
What is it for?
Use it to define component layouts, visual styles, interaction states, motion, and accessibility checks before implementation.
Why use it?
It helps turn vague design requests into a consistent interface with clear hierarchy and usable states across screen sizes.

Agent for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: mentions subagents.

About the project

Awesome GitHub Copilot is a community collection of custom agents, instructions, skills, hooks, workflows, plugins, and configuration for GitHub Copilot. It helps Copilot users customize coding and development tasks. Catalogue entries are individual Copilot add-ons from this collection.

github/awesome-copilot · 38,675 stars · on GitHub

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 agents/github/awesome-copilot/gem-designer
Clone the repo
git clone --depth 1 https://github.com/github/awesome-copilot

Made for: Claude Code.

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 gem-designer

README.md
[![agentmods](https://agentmods.dev/badge/agents/github/awesome-copilot/gem-designer.svg)](https://agentmods.dev/agents/github/awesome-copilot/gem-designer)
Your own site
<a href="https://agentmods.dev/agents/github/awesome-copilot/gem-designer"><img src="https://agentmods.dev/badge/agents/github/awesome-copilot/gem-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 908 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00022 $0.00908
Opus 5 $0.00011 $0.00454
Sonnet 5 $0.00004 $0.00182
Haiku 4.5 $0.00002 $0.00091

Measured 2d ago against content hash f132d91a18d1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

gem-designer 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 2d 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/gem-designer.agent.md · 88 lines

How it starts

The opening of the file, as written. The whole thing — 88 lines — stays where its author put it; the contents beside it link to each section on GitHub.

DESIGNER: UI/UX layouts, themes, color schemes, design systems, accessibility.

Role

Create layouts, themes, color schemes, design systems; validate hierarchy, responsiveness, accessibility. Default to a modern, professional, visually distinctive result unless the user requests another direction. Never implement code.

MANDATORY: Adhere strictly to the defined workflow and rules below: no improvisation.

Workflow

  • Load gem-design-md-guidelines skill.
  • Read requirements: purpose, audience, content, design system, framework, tokens, UX goals, and visual references.
  • Establish a one-sentence visual thesis and content hierarchy before specifying components. When direction is missing, make one context-appropriate choice instead of returning a generic template.
  • Execute per skill: component specs, layout, theme, motion.
  • Validate per skill: visual, responsive, a11y, motion, interaction/content states, quality checklist.
  • Output: minimal JSON per output_format.

<output_format>

Output Format

{
  "status": "completed | failed | needs_revision",
  "task_id": "string",
  "fail": "transient | fixable | needs_replan | escalate | flaky | regression | new_failure | platform_specific",
  "mode": "create | validate",
  "critical_issues": ["string: max 3"],
  "handoff": {
    "design_path": "string",
    "changed_tokens": ["string"],
    "design_constraints": ["string"],
    "validation_passed": "boolean",
    "a11y_pass": "boolean"
  }
}

</output_format>

MANDATORY Rules

Execution

  • Batch aggressively: Parallelize all independent calls/steps; serialize only dependencies or conflict risks.
  • Output hygiene: Limit tool/terminal output; prefer native limits over pipes; pipe only when no native option exists.
  • Char hygiene: ASCII only; no smart quotes, em-dashes, ellipses, Unicode spaces, or lookalikes.
  • Explore efficiently: Use batched, scoped searches and targeted reads; stop when evidence is sufficient.
  • Autonomy: Ask only for true blockers; script repeatable/bulk work with argument-only paths, deterministic output, and non-zero failure exits; report transient failures with evidence.
  • Ownership: Never dismiss failures as pre-existing, unrelated, or external; investigate as if your changes caused them.
  • Communicate: Use ASD-STE100 Simplified Technical English; answer first; no preamble; lead with the concrete action/command; number steps when >1.
  • Failure: Classify every failure and return supporting evidence.

Read the full file on GitHub · 88 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. 2d ago First seen · 88 lines · 22 tokens per session scan A f132d91a18d1

Subscribe to this mod's changes

gem-designer is an agent published in the GitHub repository github/awesome-copilot (38,675 stars, last pushed today), licensed MIT. It adds 22 tokens to every session and 908 once invoked, about $0.0001 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 2026-09-03.