PixelPilot uiux-mcp-setup.instructions.md

Configuration guidance for connecting Chrome DevTools and Lighthouse through the Model Context Protocol, a way for tools and agents to exchange commands and results. It includes setup details for automated browser-based interface and performance checks.

In plain words
What is it for?
Use it to configure Chrome DevTools for accessibility checks and Lighthouse CLI for website performance assessments in OpenCode.
Why use it?
It explains how to connect the browser tools needed for repeatable audits instead of checking every page manually. The setup supports headless Chrome, which runs without a visible browser window.

Instructions file for GitHub Copilot

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 instructions/dev-lou/pixelpilot/uiux-mcp-setup
Clone the repo
git clone --depth 1 https://github.com/dev-lou/PixelPilot

Made for: GitHub Copilot.

Per session 1,097 This file is loaded in full into every session.
When invoked 1,097 The same file — it is already loaded in full.
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 $0.01097 $0.01097
Opus 5 $0.00549 $0.00549
Sonnet 5 $0.00219 $0.00219
Haiku 4.5 $0.00110 $0.00110

Measured 2d ago against content hash 8a17fd823a6c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

PixelPilot uiux-mcp-setup.instructions.md 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 2d 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.

vscode/.github/instructions/uiux-mcp-setup.instructions.md · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OpenCode UI/UX 2026 — MCP Server Setup

This document provides concrete configuration snippets for setting up Model Context Protocol (MCP) servers for Chrome DevTools and Lighthouse CLI. These configurations are essential for automating UI/UX audits and performance assessments within the OpenCode design system. Both tools are free and open source, ensuring broad accessibility and cost-effectiveness.

1. Chrome DevTools MCP Configuration

This configuration enables the uiux-audit-automation.md skill to interact with Chrome DevTools for automated accessibility (axe-core) scans and other UI/UX audits. The MCP server facilitates programmatic control over a headless Chrome instance, allowing for consistent and repeatable testing.

opencode.json Snippet

Add the following object to the servers array within your opencode.json file. Ensure the port is unique if you have other MCP servers running.

{
  "name": "chrome-devtools-mcp",
  "type": "devtools",
  "port": 9222, // Default Chrome DevTools port
  "args": [
    "--headless=new",
    "--disable-gpu",
    "--remote-debugging-port=9222",
    "--no-sandbox" // Required for some environments, use with caution
  ],
  "chromePath": "/usr/bin/google-chrome" // Adjust based on your Chrome installation path
}

Verification Steps

After adding the configuration and restarting your MCP client, you can verify the server is running and accessible using the /mcp list command:

/mcp list

You should see chrome-devtools-mcp listed among the active servers. You can also try to connect to localhost:9222 in your browser to confirm the headless Chrome instance is listening.

Troubleshooting Tips

  • Chrome Path: Ensure chromePath points to the correct executable for your system. Common paths include /usr/bin/google-chrome, /usr/bin/chromium-browser, or /Applications/Google Chrome.app/Contents/MacOS/Google Chrome on macOS.
  • Permissions: If you encounter permission errors, ensure the user running the MCP server has execute permissions for the Chrome executable. The --no-sandbox flag can resolve some issues in containerized environments but should be used judiciously due to security implications.
  • Port Conflicts: If port 9222 is already in use, choose another available port and update the port and remote-debugging-port values accordingly.

Read the full file on GitHub · 91 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. 2d ago First seen · 91 lines · 1,097 tokens per session scan A 8a17fd823a6c

Subscribe to this mod's changes

PixelPilot uiux-mcp-setup.instructions.md is an instructions file published in the GitHub repository dev-lou/PixelPilot (2 stars, last pushed 4mo ago), licensed MIT. It adds 1,097 tokens to every session, about $0.0055 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.