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 skills add aryanduntley/pwa-debug-layer --skill chrome-devtools-coexistencegit clone --depth 1 https://github.com/aryanduntley/pwa-debug-layerWrote 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.
[](https://agentmods.dev/skills/aryanduntley/pwa-debug-layer/chrome-devtools-coexistence)<a href="https://agentmods.dev/skills/aryanduntley/pwa-debug-layer/chrome-devtools-coexistence"><img src="https://agentmods.dev/badge/skills/aryanduntley/pwa-debug-layer/chrome-devtools-coexistence/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.
<a href="https://agentmods.dev/skills/aryanduntley/pwa-debug-layer/chrome-devtools-coexistence"><img src="https://agentmods.dev/badge/skills/aryanduntley/pwa-debug-layer/chrome-devtools-coexistence.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00067 | $0.01740 |
| Opus 5.5 | $0.00027 | $0.00696 |
| Sonnet 5.5 | $0.00013 | $0.00348 |
| Haiku 4.5 | $0.00007 | $0.00174 |
Grade A, and why
chrome-devtools-coexistence 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.
How it starts
The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.
pwa-debug and chrome-devtools-mcp are two separate MCP servers. pwa-debug
exposes framework/store/DOM state; chrome-devtools-mcp drives the browser
(snapshots, input, performance). They share one browser: pdl_launch_browser
spawns it with the debug port live, and chrome-devtools-mcp attaches to that
port via --browserUrl. This skill covers making chrome-devtools-mcp's tools
appear after you register it, and preserving context across the restart that
sometimes requires.
When to use
- Right after
pdl_register_chrome_devtools(or a manualclaude mcp add chrome-devtools …). - When the user reports that chrome-devtools tools are not available even though the registration looks correct.
- When
pdl_check_setupreports chrome-devtools-mcp as not registered, unpinned (no--browserUrl→ it spawns its own isolated browser instead of attaching to the pwa-debug browser), or pointed at the wrong port.
The one rule that drives everything
A newly added or re-pinned MCP server only takes effect when Claude Code (re)connects it. How you trigger that depends on the install mode:
| Install mode | How chrome-devtools tools (re)load | Full restart? | Context lost? |
|---|---|---|---|
Direct MCP (claude mcp add …) |
/mcp → reconnect the server, or restart Claude Code |
Usually no (reconnect) | Only if you full-restart — see handoff |
| Plugin (bundled MCP server) | Enable in /plugins, then run /reload-plugins |
No (same session) | No |
/mcp reconnect picks up a changed registration. Verified in practice: after
claude mcp remove chrome-devtools + claude mcp add … --browserUrl http://127.0.0.1:<port>,
a /mcp → reconnect on chrome-devtools reloaded it with the new --browserUrl
and it attached to the pwa-debug browser — no full restart, no context loss.
Try /mcp reconnect first. If the client doesn't show it connected (some clients
won't load a brand-new server without a restart), fall back to a full restart and
do the context handoff below first. Plugin installs always prefer
/reload-plugins.
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 First seen · 110 lines · 67 tokens per session scan A 10dccde2b751
chrome-devtools-coexistence is a skill published in the GitHub repository aryanduntley/pwa-debug-layer (0 stars, last pushed 4mo ago), licensed MIT. It adds 67 tokens to every session and 1,740 once invoked, about $0.0003 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 2026-08-31.
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