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.
npx skills add wiolett-industries/marketplace --skill ui-contractgit clone --depth 1 https://github.com/wiolett-industries/marketplaceWrote 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/skills/wiolett-industries/marketplace/ui-contract)<a href="https://agentmods.dev/skills/wiolett-industries/marketplace/ui-contract"><img src="https://agentmods.dev/badge/skills/wiolett-industries/marketplace/ui-contract/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/skills/wiolett-industries/marketplace/ui-contract"><img src="https://agentmods.dev/badge/skills/wiolett-industries/marketplace/ui-contract.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 | $0.00057 | $0.00684 |
| Opus 5 | $0.00028 | $0.00342 |
| Sonnet 5 | $0.00011 | $0.00137 |
| Haiku 4.5 | $0.00006 | $0.00068 |
Grade A, and why
ui-contract 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 11d 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 — 46 lines — stays where its author put it; the contents beside it link to each section on GitHub.
UI Contract
Support production UI within the active workflow and its existing agent budget.
Mockup And Prototype Fast Path
For an explicitly bounded mockup, concept, or prototype, create no durable contract unless requested. Inspect the viewport/objective once; check only clipping, overlap, unreadable copy, broken assets, and major hierarchy failures; use no UI review agent under fast; stop after one successful visual pass. Do not invent production state matrices, breakpoints, or reusable behavior.
Production Define Mode
UI Reuse Gate
Before production JSX, CSS, or layout, inspect the closest screen, shared primitives, layout/responsive patterns, and tokens.
UI Reuse Receipt
Before the first edit, record in ui-contract.md or chat the target, shared path/export, layout precedent, reuse/adapt/none, and planned structural verification; reuse-gate.md defines the exact receipt. Named reuse is an architecture acceptance criterion, not visual equivalence. Resolve its path/export; do not substitute local markup or wrappers without explicit approval. Component reuse alone is insufficient; none needs evidence.
Reuse/adapt the closest primitive and named layout precedent. Do not introduce one-off components, arbitrary font/size/spacing values, or a parallel responsive/layout pattern when an established local pattern covers the need. A “shared components only” constraint forbids custom components/wrappers; compose/adapt or ask. Otherwise, a new primitive needs evidence no candidate fits.
Before substantial undecided production UI implementation, create/update the active plan's ui-contract.md; smaller named-reuse tasks record the receipt in chat. Include only acceptance-relevant details:
- objective and user job;
- surfaces and primary hierarchy/actions;
- typography, spacing, density, color/emphasis, icons, and copy constraints;
- accepted responsive targets;
- relevant loading, error, empty, disabled, partial, hover, focus, and success states;
- accessibility, overflow, and layout-stability constraints;
- reuse decision and any justified new primitive;
- non-goals and review acceptance criteria.
What ships with it
1 file 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.
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.
- 11d ago First seen · 46 lines · 57 tokens per session scan A 426e14b7da4e
ui-contract is a skill published in the GitHub repository wiolett-industries/marketplace (10 stars, last pushed 5d ago), licensed MIT. It adds 57 tokens to every session and 684 once invoked, about $0.0003 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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