browser-debugging

browser-debugging is a skill for Claude Code, Codex from MadAppGang/claude-code. It costs 71 tokens per session (4,295 once invoked), scanned A, original, MIT.

A browser-based testing and debugging guide for checking whether a web interface works and looks as expected. It covers visual comparisons, console errors, network requests, user interactions, and regression checks in Chrome.

In plain words
What is it for?
Use it to validate implemented UI features, reproduce browser bugs, inspect console and network activity, and compare a page with a design reference.
Why use it?
It helps find problems that may only appear in a real browser, such as broken interactions, layout changes, or failed requests.

Skill for Claude CodeCodex

Part of the dev plugin — 47 skills, 12 commands, 14 agents 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/madappgang/claude-code/browser-debugging
Any agent
npx skills add MadAppGang/claude-code --skill browser-debugging
Clone the repo
git clone --depth 1 https://github.com/MadAppGang/claude-code

Made for: Claude Code, Codex.

Or install dev, the plugin that ships this one along with the rest of its 47 skills, 12 commands, 14 agents.

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 browser-debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/madappgang/claude-code/browser-debugging.svg)](https://agentmods.dev/skills/madappgang/claude-code/browser-debugging)
Your own site
<a href="https://agentmods.dev/skills/madappgang/claude-code/browser-debugging"><img src="https://agentmods.dev/badge/skills/madappgang/claude-code/browser-debugging.svg" alt="Measured on agentmods" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,295 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 $0.00071 $0.04295
Opus 5 $0.00036 $0.02148
Sonnet 5 $0.00014 $0.00859
Haiku 4.5 $0.00007 $0.00430

Measured yesterday against content hash 73aa096d90b2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

browser-debugging 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 yesterday.

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/dev/skills/frontend/browser-debugging/SKILL.md · 614 lines

How it starts

The opening of the file, as written. The whole thing — 614 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Browser Debugging

This Skill provides comprehensive browser-based UI testing, visual analysis, and debugging capabilities using Claude-in-Chrome Extension MCP tools and optional external vision models via Claudish.

When to Use This Skill

Claude and agents (developer, reviewer, tester, ui-developer) should invoke this Skill when:

  • Validating Own Work: After implementing UI features, agents should verify their work in a real browser
  • Design Fidelity Checks: Comparing implementation screenshots against design references
  • Visual Regression Testing: Detecting layout shifts, styling issues, or visual bugs
  • Console Error Investigation: User reports console errors or warnings
  • Form/Interaction Testing: Verifying user interactions work correctly
  • Pre-Commit Verification: Before committing or deploying code
  • Bug Reproduction: User describes UI bugs that need investigation

Prerequisites

Required: Claude-in-Chrome Extension

This skill requires Claude-in-Chrome Extension MCP. The extension provides browser automation tools directly through Claude.

Check if available: The tools are available when the extension is installed and active. Look for mcp__claude-in-chrome__* tools in your available MCP tools.

Optional: External Vision Models (via OpenRouter)

For advanced visual analysis, use external vision-language models via Claudish:

# Check OpenRouter API key
[[ -n "${OPENROUTER_API_KEY}" ]] && echo "OpenRouter configured" || echo "Not configured"

# Install claudish
npm install -g claudish

For best visual analysis of UI screenshots, use these models via Claudish:

Tier 1: Best Quality (Recommended for Design Validation)

Model Strengths Cost Best For
qwen/qwen3-vl-32b-instruct Best OCR, spatial reasoning, GUI automation, 32+ languages ~$0.06/1M input Design fidelity, OCR, element detection
google/gemini-2.5-flash Fast, excellent price/performance, 1M context ~$0.05/1M input Real-time validation, large pages
openai/gpt-4o Most fluid multimodal, strong all-around ~$0.15/1M input Complex visual reasoning

Read the full file on GitHub · 614 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. yesterday First seen · 614 lines · 71 tokens per session scan A 73aa096d90b2

Subscribe to this mod's changes

browser-debugging is a skill published in the GitHub repository MadAppGang/claude-code (279 stars, last pushed 5mo ago), licensed MIT. It adds 71 tokens to every session and 4,295 once invoked, about $0.0004 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 2026-09-03.

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