What is chrome-devtools-mcp?

A connection that lets a coding agent inspect and control Chrome through an MCP server. It can expose browser information such as console messages, network traffic, screenshots, traces, the page structure, and DOM state.

Use it to debug and automate ASP.NET Core, Blazor, WebAssembly, or other .NET web interfaces in Chrome.

It lets an agent investigate a running web application at browser level instead of examining server code alone. This is useful for problems that only appear when the page loads or interacts with the browser.

chrome-devtools-mcp — Skill for Claude Code and Codex by managedcode

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.

Any agent

npx skills add managedcode/dotnet-skills --skill chrome-devtools-mcp

Clone the repo

git clone --depth 1 https://github.com/managedcode/dotnet-skills

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/managedcode/dotnet-skills/chrome-devtools-mcp/github.svg)](https://agentmods.dev/skills/managedcode/dotnet-skills/chrome-devtools-mcp)

Your own site

<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/chrome-devtools-mcp"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/chrome-devtools-mcp/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/chrome-devtools-mcp"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/chrome-devtools-mcp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 130 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,074 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. Third-party audits

NVIDIA SkillSpector warn 7 Sept 2026

SkillSpector: 3 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

medium MCP Rug Pull · line 94
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium Rogue Agent · line 105
Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.

Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
medium MCP Rug Pull · line 163
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00130	$0.02074
Opus 5.5	$0.00052	$0.00830
Sonnet 5.5	$0.00026	$0.00415
Haiku 4.5	$0.00013	$0.00207

Measured 1mo ago against content hash ef7216b2082c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

chrome-devtools-mcp 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 1mo 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.

catalog/Tools/Chrome-DevTools-MCP/skills/chrome-devtools-mcp/SKILL.md · 173 lines

How it starts

The opening of the file, as written. The whole thing — 173 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Chrome DevTools MCP for .NET Repos

Trigger On

the repo needs browser-level debugging for ASP.NET Core, Blazor, WebAssembly, or any .NET app with a web UI
the user wants an MCP server that can inspect console output, network traffic, screenshots, traces, and DOM state
the repo needs agent-friendly browser control instead of manual DevTools work

Do Not Use For

pure .NET code analysis, unit testing, or NuGet/package management
static HTML linting alone
sensitive browser sessions that must not be exposed to an MCP client

Inputs

the nearest AGENTS.md
the MCP client config for the current agent or app
the target Chrome mode: launch new, connect to existing browser, or attach to a WebSocket endpoint
the target app URL or local dev server

Workflow

Choose the browser mode first.
- new ephemeral browser: default when you want a clean session
- existing browser: use --browserUrl or --wsEndpoint
- running browser with a user profile: use --autoConnect only when Chrome 144+ and remote debugging are already enabled
Prefer repo-local config over ad hoc shell commands.
- store the MCP server block in the repo or agent config so every run is repeatable
Start from the smallest useful surface.
- use --slim when you only need navigation, JavaScript execution, and screenshots
- leave the full toolset enabled when you need network, performance, or emulation
Be explicit about privacy and cost.
- disable usage statistics or CrUX-backed performance enrichment when policy or sensitivity requires it
Validate against the real app, not a mock page.
- use the app's local dev server, preview URL, or a production-like environment that reflects the bug

Current Upstream Notes

Chrome DevTools MCP v1.8.0 adds PWA automation, query_heapsnapshot, richer heap-edge and native-context inspection, console stack traces, multi-file upload, and a stable-DOM bypass for evaluate_script. Enable memory-debugging tools explicitly and keep heap output bounded to the investigation.
Page-scoped tools now require pageId by default. Update callers to select and pass the intended page instead of relying on ambient tab state. The release also fixes CLI default handling, remote-path validation, HiDPI screenshot bounds, slow-client root listing, and lifecycle regressions; reproduce the real browser path before adding client-side workarounds.
Use the memory tools only when heap snapshots are the actual debugging need; close snapshots when finished so the browser session does not keep unnecessary memory pressure.
For sensitive or scoped browser automation, prefer allowedUrlPattern / blockedUrlPattern over relying only on prompt instructions.
When enabling category extensions, prompt the user for the category instead of silently broadening the tool surface.

Read the full file on GitHub · 173 lines

Files

What ships with it

1 file 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.

manifest.json 123 B

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.

1mo ago Changed ef7216b2082c
1mo ago First seen · 173 lines · 130 tokens per session scan A 140d6f652ec1

Subscribe to this mod's changes

chrome-devtools-mcp is a skill published in the GitHub repository managedcode/dotnet-skills (490 stars, last pushed 3d ago), licensed MIT. It adds 130 tokens to every session and 2,074 once invoked, about $0.0005 per session on Opus 5.5. 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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