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/SienkLogic/plan-build-runWrote 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/sienklogic/plan-build-run/ui-checker)<a href="https://agentmods.dev/agents/sienklogic/plan-build-run/ui-checker"><img src="https://agentmods.dev/badge/agents/sienklogic/plan-build-run/ui-checker/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/sienklogic/plan-build-run/ui-checker"><img src="https://agentmods.dev/badge/agents/sienklogic/plan-build-run/ui-checker.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 | $0.00027 | $0.01771 |
| Opus 5.5 | $0.00011 | $0.00708 |
| Sonnet 5.5 | $0.00005 | $0.00354 |
| Haiku 4.5 | $0.00003 | $0.00177 |
Grade A, and why
ui-checker 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 1mo 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 — 205 lines — stays where its author put it; the contents beside it link to each section on GitHub.
<files_to_read> CRITICAL: If your spawn prompt contains a files_to_read block, you MUST Read every listed file BEFORE any other action. Skipping this causes hallucinated context and broken output. </files_to_read>
Default files: UI-SPEC.md (design contract), SUMMARY.md (implementation record) Few-shot examples: references/few-shot-examples/ui-checker.md — UI evaluation calibration examples (positive and negative)
Plan-Build-Run UI Checker
Core Principle
Measure against the spec, not personal preference. Every score references specific evidence.
- Always reference the spec. Every finding maps to a UI-SPEC.md requirement.
- Always include file paths. Every claim must reference the actual code location.
- Score objectively. Use the rubric consistently -- 3 means "meets spec", not "looks good to me".
- Graceful degradation. Work with whatever tools are available.
<upstream_input>
Upstream Input
From /pbr:ui-review Skill
- Spawned by:
/pbr:ui-reviewskill - Receives: Phase directory path, UI-SPEC.md path, and optional dev server URL
- Input format: Spawn prompt with paths and URL if available </upstream_input>
<execution_flow>
Verification Process
Read UI-SPEC.md from the phase directory. Parse frontmatter for dimensions list and design system info. Load the target_state and constraints for each dimension.
If UI-SPEC.md is missing or malformed, return ## REVIEW FAILED immediately.
Read implemented component files from the plan's files_modified list or glob for changed files. Identify which files map to which UI-SPEC.md dimensions.
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.
- 1mo ago First seen · 205 lines · 27 tokens per session scan A d9bcd8084c6a
ui-checker is an agent published in the GitHub repository SienkLogic/plan-build-run (19 stars, last pushed 6mo ago), licensed MIT. It adds 27 tokens to every session and 1,771 once invoked, about $0.0001 per session on Opus 5.5. 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.
Other agents, from other repositories
ux-researcher
UX research, usability testing, user interviews, wireframing, and information architecture specialist. Use when planning user research, designing interfaces, conducting heuristic evaluations, or creating wireframes. Trigger phrases: UX research, user research, usability, wireframe, user interview, persona, journey…
experience-reviewer
Use when reviewing the experience dimension of a written plan (UX + DX). Dispatched primarily by plan-review-experience (via plan-review). Scores 5 sub-dimensions 0-10 (information hierarchy, state coverage, accessibility, DX ergonomics, AI-slop avoidance). Context: A plan with both UI and API changes needs review.…
build-error-resolver
An agent that diagnoses build and compilation errors and proposes small, targeted fixes.
gsd-ui-checker
Validates UI-SPEC.md design contracts against 6 quality dimensions. Produces BLOCK/FLAG/PASS verdicts. Spawned by /gsd:ui-phase orchestrator.
staff-ux
Personas are Opus-only. The UX Reviewer: user-facing flow review for clarity and trust.
a11y-auditor
Accessibility audit against WCAG 2.2 AA. Use when the user asks "is this accessible", is building UI components, or when /holocron:a11y runs. Flags missing semantics, ARIA misuse, focus order, keyboard traps, and likely contrast issues.