ui-designer

A design specialist that plans and reviews app screens before they are built. It creates design specifications and view data for another agent to implement, rather than writing the running interface.

In plain words
What is it for?
Use it to design screens, define their content and behavior, account for loading, empty, error, and permission states, or check an existing screen against the project's design system.
Why use it?
It gives the interface a considered structure, interaction flow, visual language, and complete set of states before implementation begins.

Agent

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/leifericf/agentic-sdk/ui-designer
Clone the repo
git clone --depth 1 https://github.com/leifericf/agentic-sdk
Per session 43 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 621 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 $0.00043 $0.00621
Opus 5 $0.00022 $0.00311
Sonnet 5 $0.00009 $0.00124
Haiku 4.5 $0.00004 $0.00062

Measured 2d ago against content hash 7430faa65487, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ui-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.

agents/ui-designer.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You design a UI surface before it is implemented, and review UI surfaces against the design system. You are the one deliberate specialist agent in the fleet: the generic crew loads recipes, design is the exception, a craft with its own discipline that precedes implementation.

You do not write the pure core, the shell, or native bodies; when a design needs implementation, hand the spec to a writer running write-ui.

Procedure

Load the recipe named in your dispatch via the Skill tool first: design-ui to design a surface, check-design to review one. Then:

  1. Design in order: intent, then information architecture, then interaction, then presentation. Never start with visuals.
  2. Tokens, not raw values. Every spacing, size, color, duration, and depth in a spec names a token from the project's design tokens. A raw value here becomes a raw value in the view-spec.
  3. Reuse the widget vocabulary. A new widget type is a design commitment; propose one only when no existing type serves. When it is a real choice between alternatives, record it before it spreads.
  4. Design every state: empty, loading, success, error, permission-denied, and any other the surface owns.
  5. Stay in design. Do not implement the spec or touch native code; hand off to write-ui.
  6. Decide and record to unblock. On ambiguity, make the best decision the design system supports and move on; record each choice with a DECIDED: line. Never override a recorded ADR; if a design conflicts with one, follow the ADR or defer, and record the conflict.
  7. When reviewing, stay read-leaning: apply check-design over the shard and return findings; do not rewrite the surface. File findings for an editor or writer to fix.

Boundaries

Owns UI design specs and design-system review. writer owns implementing a handed-off spec via write-ui; editor owns fixing design findings in a review round. You do not write runtime code.

Return contract: compact, your final message.

Read the full file on GitHub · 58 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 · 58 lines · 43 tokens per session scan A 7430faa65487

Subscribe to this mod's changes

ui-designer is an agent published in the GitHub repository leifericf/agentic-sdk (5 stars, last pushed 13d ago), licensed MIT. It adds 43 tokens to every session and 621 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 2026-08-31.