validate-ui-scenario

validate-ui-scenario is a skill for Claude Code, Codex from microsoft/vscode. It costs 75 tokens per session (2,804 once invoked), scanned B, original, MIT.

Use when reproducing a UI bug or verifying a fix by driving a real VS Code window end to end and capturing evidence. Writes a scenario file, runs it against a dev build or installed Insiders, and produces a captioned video, per-step screenshots, a Playwright trace, and an HTML report to attach to an issue or pull…

Skill for Claude CodeCodex

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/microsoft/vscode/validate-ui-scenario
Any agent
npx skills add microsoft/vscode --skill validate-ui-scenario
Clone the repo
git clone --depth 1 https://github.com/microsoft/vscode

Made for: Claude Code, Codex.

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 validate-ui-scenario

README.md
[![agentmods](https://agentmods.dev/badge/skills/microsoft/vscode/validate-ui-scenario.svg)](https://agentmods.dev/skills/microsoft/vscode/validate-ui-scenario)
Your own site
<a href="https://agentmods.dev/skills/microsoft/vscode/validate-ui-scenario"><img src="https://agentmods.dev/badge/skills/microsoft/vscode/validate-ui-scenario.svg" alt="Measured on agentmods" height="20"></a>
Per session 75 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,804 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. 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 $0.00075 $0.02804
Opus 5 $0.00037 $0.01402
Sonnet 5 $0.00015 $0.00561
Haiku 4.5 $0.00007 $0.00280

Measured today against content hash 44874cab7a0e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

validate-ui-scenario scanned grade B with 1 finding 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 today.

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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

| Linux | `sudo apt install ffmpeg` |
.github/skills/validate-ui-scenario/SKILL.md · 244 lines

How it starts

The opening of the file, as written. The whole thing — 244 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Validate UI Scenario

Drives a real VS Code instance through a scenario and records reproducible evidence.

Use this to reproduce a reported bug, to show that a fix works, or to attach a recording to a test-plan item. For deterministic regression coverage that runs on every build, write a smoke test instead (see the smoke-tests skill) — this skill is for one-off, issue-derived validation.

A scenario is a small JavaScript file run by test/scenario/out/runScenario.js. Nothing else has to be configured: the runner launches VS Code, records video and a trace, captures a screenshot at every step boundary, writes the report, and captions the recording with each step and its result.

Prepare

npm install                             # once
npm --prefix test/scenario run compile  # after any change under test/scenario

Check ffmpeg and ffprobe are available before running. The runner looks on PATH and in the usual install locations, so an ffmpeg installed after the editor started is still found. Without them the scenario still runs and keeps the raw recording, but the video is not captioned with step titles. The runner warns at startup; if they are missing, tell the user how to install them rather than silently returning an unannotated video:

Platform Install
Windows winget install Gyan.FFmpeg
macOS brew install ffmpeg
Linux sudo apt install ffmpeg

A new terminal may be needed for PATH to pick them up, or set FFMPEG_PATH and FFPROBE_PATH. An existing run can be annotated afterwards with node test/scenario/out/renderEvidenceChapters.js <run-dir>.

Target Flags Also required Use for
Installed Insiders, else Stable (none — the default) nothing Reproducing a report against shipped behavior
Dev build from this checkout --dev npm run electron, npm run transpile-client Verifying an unmerged change
A specific install --build <app-root> nothing Pinning an exact build
Web --web --headless npm run transpile-client Browser-only behavior

Read the full file on GitHub · 244 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. today First seen · 244 lines · 75 tokens per session scan B 44874cab7a0e

Subscribe to this mod's changes

validate-ui-scenario is a skill published in the GitHub repository microsoft/vscode (190,808 stars, last pushed today), licensed MIT. It adds 75 tokens to every session and 2,804 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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