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.
npx agentmods add skills/opencodeengineer/chrome-devtools-mcp/chrome-devtoolsnpx skills add OpenCodeEngineer/chrome-devtools-mcp --skill chrome-devtoolsgit clone --depth 1 https://github.com/OpenCodeEngineer/chrome-devtools-mcpWhat 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 | $0.00055 | $0.00647 |
| Opus 5 | $0.00028 | $0.00324 |
| Sonnet 5 | $0.00011 | $0.00129 |
| Haiku 4.5 | $0.00006 | $0.00065 |
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 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.
This is a copy
83% identical to chrome-devtools — 30 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Core Concepts
Browser lifecycle: Browser starts automatically on first tool call using a persistent Chrome profile. Configure via CLI args in the MCP server configuration: npx chrome-devtools-mcp@latest --help. To enable extensions, use --categoryExtensions.
Page selection: Tools operate on the currently selected page. Use list_pages to see available pages, then select_page to switch context.
Element interaction: Use take_snapshot to get page structure with element uids. Each element has a unique uid for interaction. If an element isn't found, take a fresh snapshot - the element may have been removed or the page changed.
Workflow Patterns
Before interacting with a page
- Navigate:
navigate_pageornew_page - Wait:
wait_forto ensure content is loaded if you know what you look for. - Snapshot:
take_snapshotto understand page structure - Interact: Use element
uids from snapshot forclick,fill, etc.
Efficient data retrieval
- Use
filePathparameter for large outputs (screenshots, snapshots, traces) - Use pagination (
pageIdx,pageSize) and filtering (types) to minimize data - Set
includeSnapshot: falseon input actions unless you need updated page state
Tool selection
- Automation/interaction:
take_snapshot(text-based, faster, better for automation) - Visual inspection:
take_screenshot(when user needs to see visual state) - Additional details:
evaluate_scriptfor data not in accessibility tree
Parallel execution
You can send multiple tool calls in parallel, but maintain correct order: navigate → wait → snapshot → interact.
Testing an extension
- Install: Use
install_extensionwith the path to the unpacked extension. - Identify: Get the extension ID from the response or by calling
list_extensions. - Trigger Action: Use
trigger_extension_actionto open the popup or side panel if applicable. - Verify Service Worker: Use
evaluate_scriptwithserviceWorkerIdto check extension state or trigger background actions. - Verify Page Behavior: Navigate to a page where the extension operates and use
take_snapshotto check if content scripts injected elements or modified the page correctly.
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.
- yesterday First seen · 54 lines · 55 tokens per session scan A a03725037f6a
chrome-devtools is a skill published in the GitHub repository OpenCodeEngineer/chrome-devtools-mcp (1 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 55 tokens to every session and 647 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 83% identical to chrome-devtools, differing in 30 lines, and is treated as a copy.
Other skills, from other repositories
general-video
Author or edit a custom HyperFrames composition when no specialized workflow fits, or when BRIEF.md sets flow: companion. Use for longer or multi-scene pieces, brand and sizzle reels, montages, static loops, static title cards, footage remixes, and freeform builds. Use motion-graphics instead for a short unnarrated…
use-agent-browser-for-airi
Test AIRI display-model imports with agent-browser across stage-tamagotchi Electron, stage-web, and stage-pocket mobile web layouts. Use when uploading and verifying contributor-supplied Live2D ZIP, VRM, or MMD ZIP/PMX/PMD files through AIRI's model selector, including onboarding bypass, format-specific import…
opencli-sitemap-author
Use when creating or maintaining OpenCLI site sitemaps: agent-facing navigation, page-state, action, workflow, API-reference, pitfall, and fallback knowledge for a website. Use after browser exploration discovers durable site context, when a sitemap is stale, or when promoting local site knowledge into the repo.
debug-optimize-lcp
Guides debugging and optimizing Largest Contentful Paint (LCP) using Chrome DevTools MCP tools. Use this skill whenever the user asks about LCP performance, slow page loads, Core Web Vitals optimization, or wants to understand why their page's main content takes too long to appear. Also use when the user mentions…
pinchtab-mcp
Use this skill when a task requires browser automation through PinchTab's MCP server connected to a remote browser instance. Covers navigation, element interaction, data extraction, form filling, multi-step flows, and session management via MCP tools.
mintlify-preview
Run the public Mintlify product docs site locally for live preview. Use when previewing or iterating on docs under docs/ (.mdx/.md pages, docs.json nav), or when the user says "start the docs", "run mintlify", "preview the docs site".