ui-checker

ui-checker is an agent for Claude Code from SienkLogic/plan-build-run. It costs 27 tokens per session (1,771 once invoked), scanned A, original, MIT.

A user-interface review agent that compares an implementation with the requirements in UI-SPEC.md, a document describing how the interface should work and look.

In plain words
What is it for?
Use it to inspect a completed interface, score whether it meets its design contract, and identify specific gaps with file paths.
Why use it?
It replaces subjective visual feedback with findings tied to the written specification and actual code locations. It can also use visual checks when a browser-based review is available.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the pbr plugin — 45 skills, 71 commands, 18 agents, 3 hooks shipped together

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/sienklogic/plan-build-run/ui-checker
Clone the repo
git clone --depth 1 https://github.com/SienkLogic/plan-build-run

Made for: Claude Code.

Or install pbr, the plugin that ships this one along with the rest of its 45 skills, 71 commands, 18 agents, 3 hooks.

Wrote 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.

agentmods badge for ui-checker

README.md
[![agentmods](https://agentmods.dev/badge/agents/sienklogic/plan-build-run/ui-checker.svg)](https://agentmods.dev/agents/sienklogic/plan-build-run/ui-checker)
Your own site
<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="Measured on agentmods" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,771 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 5.1 $0.00027 $0.01771
Opus 5 $0.00014 $0.00886
Sonnet 5 $0.00005 $0.00354
Haiku 4.5 $0.00003 $0.00177

Measured 6d ago against content hash d9bcd8084c6a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

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 6d 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.

plugins/pbr/agents/ui-checker.md · 205 lines

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-review skill
  • 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.

Read the full file on GitHub · 205 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. 6d ago First seen · 205 lines · 27 tokens per session scan A d9bcd8084c6a

Subscribe to this mod's changes

ui-checker is an agent published in the GitHub repository SienkLogic/plan-build-run (17 stars, last pushed 5mo ago), licensed MIT. It adds 27 tokens to every session and 1,771 once invoked, about $0.0001 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.

Related

Other agents, from other repositories

providers

A coding agent runs against a provider account: a login, on a plan, that may or may not be metered. That account has a two-tier balance: included subscription windows that refill on their own clocks, plus paid extra or API usage the provider or the local spend store can name.

rimio-ai/rimz · 0 tokens

model

A coding agent runs in a pane, reports through its own hooks, and appears in the sidebar as one card. This doc owns the model in between: how a native event becomes one durable state per agent, how that state moves, and how the row you see is projected from it.

rimio-ai/rimz · 0 tokens

adapter

Thirteen coding agents report to RimZ, and no code outside crates/rimz/src/agents/ knows which one it is looking at. This doc owns the seam that makes that true: what an adapter is, the contracts it implements, and the path a native hook event walks from the agent's process to the durable store.

rimio-ai/rimz · 0 tokens

adapter_copilot

GitHub Copilot CLI reports through native camelCase command hooks installed as one RimZ-owned user file at $COPILOTHOME/hooks/rimz.json, falling back to /.copilot/hooks/rimz.json. Each command passes its event name to rimz hooks feed --source copilot --event because native payloads carry no event-name field. Hook…

rimio-ai/rimz · 0 tokens

adapter_cursor

Cursor runs as agent or its cursor-agent alias; cursor names the IDE and is intentionally outside binary discovery. RimZ installs additive user hooks in /.cursor/hooks.json and a canonical command statusline in /.cursor/cli-config.json, launches a verified resolved path or the provider-unique cursor-agent alias, and…

rimio-ai/rimz · 0 tokens

adapter_opencode

This doc is the single home for everything OpenCode-specific. OpenCode's integration surface is an in-process TypeScript plugin, so the adapter ships plugin.ts, embedded at compile time and installed as /.config/opencode/plugin/rimz.ts. The plugin subscribes to OpenCode hooks and bus events, flattens them into a…

rimio-ai/rimz · 0 tokens