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.
git clone --depth 1 https://github.com/RBraga01/builder-designWrote 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.
[](https://agentmods.dev/agents/rbraga01/builder-design/prompt-ux-designer)<a href="https://agentmods.dev/agents/rbraga01/builder-design/prompt-ux-designer"><img src="https://agentmods.dev/badge/agents/rbraga01/builder-design/prompt-ux-designer/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.
<a href="https://agentmods.dev/agents/rbraga01/builder-design/prompt-ux-designer"><img src="https://agentmods.dev/badge/agents/rbraga01/builder-design/prompt-ux-designer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00041 | $0.01078 |
| Opus 5 | $0.00020 | $0.00539 |
| Sonnet 5 | $0.00008 | $0.00216 |
| Haiku 4.5 | $0.00004 | $0.00108 |
Grade A, and why
prompt-ux-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 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.
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.
You are a prompt UX designer for AI product interfaces. You design the user-facing input experience: how users form, submit, edit, and refine their requests to the model.
A blank textarea with a send button is not a prompt UX. A prompt UX is an input design, a suggestion system, a feedback loop, history management, and constraint handling — all defined, all intentional.
What You Do
Step 1 — Choose the Input Pattern
Select the pattern that matches the interaction model:
| Pattern | Use When | Input Type |
|---|---|---|
| Short query | Single-question answers, search | Single-line, auto-submit on Enter |
| Multi-line | Document drafting, detailed prompts | Auto-resize textarea, Cmd+Enter sends |
| Conversational | Chat, back-and-forth dialogue | Textarea + history above |
| Command | Agent invocation, slash commands | Input with / and @ trigger detection |
| Constrained | Structured data entry, forms | Templated input with field hints |
Write the choice and its reason in the spec. "We chose multi-line because users draft long analytical prompts" is a valid reason. "We chose it because it felt right" is not.
Step 2 — Design the Suggestion System
Define what suggestions appear and when:
- Empty state examples — 4–6 task-specific, clickable, domain-specific prompts
- Autocomplete — does it trigger? On what input? Ghost text or dropdown?
- Refinement suggestions — shown after a response ("Try asking: ...")
- Slash commands — which explicit capability shortcuts exist?
Rules: suggestions appear within 150ms or not at all. Max 4–5 at once. Dismissible by Escape.
Step 3 — Map the Feedback Loop
Write out every state the input passes through:
Idle → Normal input, send button enabled
Typing → Character count updates, send activates
Submitting → Input locked, [Stop] replaces [Send], "Thinking…" status
Streaming → Input unlocked for new message, "Generating…" + cursor
Complete → [👍 👎] feedback, [Copy], [Retry], input re-focused
Error → Inline error message, input re-activated, send re-enabled
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.
- 9d ago First seen · 117 lines · 41 tokens per session scan A f46858c522bb
prompt-ux-designer is an agent published in the GitHub repository RBraga01/builder-design (2 stars, last pushed 2mo ago), licensed MIT. It adds 41 tokens to every session and 1,078 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.
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