mcpjam-ui-testing

mcpjam-ui-testing is a skill for Claude Code, Codex from dinglebear-ai/dendrite. It costs 112 tokens per session (1,183 once invoked), scanned A, original, AGPL-3.0.

A testing guide for MCP-UI and MCP Apps interfaces, including widgets and their tool-to-interface data contracts. MCP Apps are applications that expose tools and interactive UI through the Model Context Protocol.

In plain words
What is it for?
Use it to inspect widgets in the Inspector, verify ui:// resources and structuredContent, and run conformance checks for MCP Apps implementations.
Why use it?
It helps find why a widget does not render or why the data exchanged between the server and interface is invalid. It also supports checks against MCP Apps behavior requirements.

Skill for Claude CodeCodex

Part of the testing plugin — 6 skills 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 skills/dinglebear-ai/dendrite/mcpjam-ui-testing
Any agent
npx skills add dinglebear-ai/dendrite --skill mcpjam-ui-testing
Clone the repo
git clone --depth 1 https://github.com/dinglebear-ai/dendrite

Made for: Claude Code, Codex.

Or install testing, the plugin that ships this one along with the rest of its 6 skills.

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 mcpjam-ui-testing

README.md
[![agentmods](https://agentmods.dev/badge/skills/dinglebear-ai/dendrite/mcpjam-ui-testing.svg)](https://agentmods.dev/skills/dinglebear-ai/dendrite/mcpjam-ui-testing)
Your own site
<a href="https://agentmods.dev/skills/dinglebear-ai/dendrite/mcpjam-ui-testing"><img src="https://agentmods.dev/badge/skills/dinglebear-ai/dendrite/mcpjam-ui-testing.svg" alt="Measured on agentmods" height="20"></a>
Per session 112 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,183 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00112 $0.01183
Opus 5 $0.00056 $0.00592
Sonnet 5 $0.00022 $0.00237
Haiku 4.5 $0.00011 $0.00118

Measured 5d ago against content hash 5bebc387a168, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

mcpjam-ui-testing 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 5d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/mcpjam-ui-check.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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/testing/skills/mcpjam-ui-testing/SKILL.md · 87 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Files

What ships with it

6 files 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.

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. 5d ago First seen · 87 lines · 112 tokens per session scan A 5bebc387a168

Subscribe to this mod's changes

mcpjam-ui-testing is a skill published in the GitHub repository dinglebear-ai/dendrite (1 stars, last pushed 8d ago), licensed AGPL-3.0. It adds 112 tokens to every session and 1,183 once invoked, about $0.0006 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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