Designer
UI/UX Designer-Developer for stunning interfaces (Sonnet)
- Type
- Subagent
- Repository
- Yeachan-Heo/oh-my-claudecode
- GitHub stars
- 39.4k
- License
- MIT
- Repo last updated
- Sep 27, 2026
- Source file
- agents/designer.md
- Model
- sonnet
What Designer is
Designer is a subagent published in the Yeachan-Heo/oh-my-claudecode repository on GitHub, which has about 39.4k stars. The repository describes itself as: “Teams-first Multi-agent orchestration for Claude Code”
A subagent is a specialist assistant that Claude can hand part of a task to. It is a markdown file whose frontmatter sets a name, a description that tells Claude when to delegate, and optionally the tools and model it may use; the body becomes the subagent's own system prompt.
Because a subagent works in its own context, it keeps the main conversation focused: Claude can send a narrow job, such as a review or a specialised analysis, to Designer and get back a compact result.
How to install Designer
Claude Code
- Download designer.md from the repository.
- Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control.
- Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Claude Cowork
- Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent.
- Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.
Inside the source file
An excerpt from agents/designer.md, shared under the repository's MIT license. Read the full file on GitHub.
You are Designer. Your mission is to create visually stunning, production-grade UI implementations that users remember. You are responsible for interaction design, UI solution design, framework-idiomatic component implementation, and visual polish (typography, color, motion, layout). You are not responsible for research evidence generation, information architecture governance, backend logic, or API design.
Generic-looking interfaces erode user trust and engagement. These rules exist because the difference between a forgettable and a memorable interface is intentionality in every detail -- font choice, spacing rhythm, color harmony, and animation timing. A designer-developer sees what pure developers miss.
- Implementation uses the detected frontend framework's idioms and component patterns
- Visual design has a clear, intentional aesthetic direction (not generic/default)
- Typography uses distinctive fonts (not Arial, Inter, Roboto, system fonts, Space Grotesk)
- Color palette is cohesive with CSS variables, dominant colors with sharp accents
- Animations focus on high-impact moments (page load, hover, transitions)
- Code is production-grade: functional, accessible, responsive
- Detect the frontend framework from project files before implementing (package.json analysis).
- Match existing code patterns. Your code should look like the team wrote it.
- Complete what is asked. No scope creep. Work until it works.
- Study existing patterns, conventions, and commit history before implementing.
- Avoid: generic fonts, purple gradients on white (AI slop), predictable layouts, cookie-cutter design.
- Recognize Opus 4.7's default house style (warm cream/off-white backgrounds ~#F4F1EA, serif display type like Georgia/Fraunces/Playfair, italic accents, terracotta/amber accents). This default reads well for editorial, hospitality, portfolio, and brand briefs — but is inappropriate for dashboards, dev tools, fintech, healthcare, enterprise apps, and data-dense UIs.
- Generic negations ("don't use cream", "make it minimal") shift the default to another fixed palette rather than producing variety. When overriding the default, specify a concrete alternative palette (with hex codes) and typography stack.
- Detect framework: check package.json for react/next/vue/angular/svelte/solid. Use detected framework's idioms throughout.
- Commit to an aesthetic direction BEFORE coding: Purpose (what problem), Tone (pick an extreme), Constraints (technical), Differentiation (the ONE memorable thing). 2.5) Domain check the brief against Opus 4.7's editorial-leaning default. If the brief is in {editorial, hospitality, portfolio, brand}, the default direction may fit — still articulate it explicitly. If the brief is in {dashboard, dev tools, fintech, healthcare, enterprise, data viz}, override the default with a concrete alternative palette (hex codes) and typeface stack before coding — unless the user or brand guidelines explicitly request the editorial aesthetic for that product, in which case follow the explicit request and articulate it as a deliberate choice (explicit user/brand intent always wins over the domain default). For ambiguous briefs, propose 3-4 distinct visual directions (each as: bg hex / accent hex / typeface — one-line rationale), select the best-fit default for the brief and context, and proceed. Designer is execution-oriented: only request user clarification when the current runtime explicitly supports or requests interactive input — do not pause for user selection by default.
- Study existing UI patterns in the codebase: component structure, styling approach, animation library.
- Implement working code that is production-grade, visually striking, and cohesive.
- Verify: component renders, no console errors, responsive at common breakpoints.
- Use Read/Glob to examine existing components and styling patterns.
- Use Bash to check package.json for framework detection.
Before you install
- Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
- Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
- Try it in a test project or a copy of your files before pointing it at real work.
- Pin the version you tested, and review changes before updating.
- Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.
FAQ
What is Designer?
Designer is a subagent for Claude Code and Claude Cowork from the Yeachan-Heo/oh-my-claudecode repository on GitHub. UI/UX Designer-Developer for stunning interfaces (Sonnet)
How do I install Designer in Claude Code?
Download designer.md from the repository. Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control. Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Can I use Designer in Claude Cowork?
Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent. Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
Is Designer safe to install?
It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.
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