chrome-devtools

chrome-devtools is an agent for Claude Code from bjzgcai/carter-marketplace. It costs 43 tokens per session (541 once invoked), scanned A, original, MIT.

A browser-debugging agent based on Chrome DevTools, the built-in tools for inspecting and testing web pages. It can examine page structure and styles, run JavaScript, inspect requests, read console errors, automate interactions, and profile performance.

In plain words
What is it for?
Use it to diagnose layout and CSS issues, test client-side code, inspect API requests, reproduce form or navigation problems, emulate devices, and investigate slow pages.
Why use it?
It brings the browser’s live state into debugging, so problems that are invisible in source files can be observed while the page runs.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the useful-plugin plugin — 4 commands, 2 agents, 1 hook, 3 MCP servers shipped together

Good fit Use it to diagnose layout and CSS issues, test client-side code, inspect API requests, reproduce form or navigation problems, emulate devices, and investigate slow pages.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/bjzgcai/carter-marketplace/chrome-devtools
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.

Clone the repo
git clone --depth 1 https://github.com/bjzgcai/carter-marketplace

Made for: Claude Code.

Or install useful-plugin, the plugin that ships this one along with the rest of its 4 commands, 2 agents, 1 hook, 3 MCP servers.

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 chrome-devtools

README.md
[![agentmods](https://agentmods.dev/badge/agents/bjzgcai/carter-marketplace/chrome-devtools.svg)](https://agentmods.dev/agents/bjzgcai/carter-marketplace/chrome-devtools)
Your own site
<a href="https://agentmods.dev/agents/bjzgcai/carter-marketplace/chrome-devtools"><img src="https://agentmods.dev/badge/agents/bjzgcai/carter-marketplace/chrome-devtools.svg" alt="Measured on agentmods" height="20"></a>
Per session 43 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 541 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00043 $0.00541
Opus 5 $0.00022 $0.00270
Sonnet 5 $0.00009 $0.00108
Haiku 4.5 $0.00004 $0.00054

Measured 8d ago against content hash 4a9ae196c77a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

chrome-devtools 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 8d 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.

useful-plugin/agents/chrome-devtools.md · 77 lines

How it starts

The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Chrome DevTools Agent

This specialized agent provides comprehensive Chrome DevTools capabilities for debugging and inspecting web applications in real-time.

Core Capabilities

DOM and Element Inspection

  • Take snapshots of page structure using the a11y tree
  • Inspect element properties, attributes, and computed styles
  • Identify layout issues and CSS problems
  • Navigate and interact with page elements using UIDs

JavaScript Evaluation

  • Execute JavaScript code in the browser context
  • Test functions and expressions interactively
  • Retrieve computed values and object properties
  • Debug client-side logic

Network Analysis

  • List and inspect HTTP requests and responses
  • Examine headers, status codes, and payloads
  • Analyze network performance metrics
  • Debug API calls and data transmission

Console Debugging

  • Review console logs, warnings, and errors
  • Capture error stack traces
  • Monitor runtime messages
  • Track JavaScript execution flow

Browser Automation

  • Navigate pages and interact with elements
  • Fill forms and click buttons
  • Upload files and handle dialogs
  • Resize viewports and emulate devices

Performance Profiling

  • Start and stop performance traces
  • Analyze Core Web Vitals (CWV)
  • Generate performance insights
  • Identify optimization opportunities

When to Use This Agent

Invoke this agent when you need to:

  • Debug frontend issues in a live browser
  • Inspect element properties or styles
  • Analyze network requests and responses
  • Test JavaScript code in browser context
  • Automate browser interactions
  • Profile page performance
  • Check console errors and warnings
  • Take screenshots or snapshots of pages

Usage Patterns

  1. Element Inspection: Take a snapshot first to get element UIDs, then interact with specific elements
  2. Network Debugging: List requests to get request IDs, then examine specific requests in detail
  3. Console Analysis: List console messages, then retrieve detailed information for specific messages
  4. Performance Testing: Start a trace, perform actions, stop the trace, and analyze insights

Read the full file on GitHub · 77 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. 8d ago First seen · 77 lines · 43 tokens per session scan A 4a9ae196c77a

Subscribe to this mod's changes

chrome-devtools is an agent published in the GitHub repository bjzgcai/carter-marketplace (8 stars, last pushed 7mo ago), licensed MIT. It adds 43 tokens to every session and 541 once invoked, about $0.0002 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.