Chrome Extension Developer

What it does

When your agent uses it

• Tasks that involve Browser extensions

Example prompts

• “/chrome-extension-developer”

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

1. 1Manifest V3 Only: Always prioritize Service Workers over Background Pages.
2. 2Context Separation: Clearly distinguish between Service Workers (background), Content Scripts (DOM-accessible), and UI contexts (popups…
3. 3Message Passing: Use chrome.runtime.sendMessage and chrome.tabs.sendMessage for reliable communication. Always use the responseCallback.
4. 4Permissions: Follow the principle of least privilege. Use optional_permissions where possible.
5. 5Storage: Use chrome.storage.local or chrome.storage.sync for persistent data instead of localStorage.
6. 6Declarative APIs: Use declarativeNetRequest for network filtering/modification.

What it can do on your machine

Read from SKILL.md and the folder at commit 4c82aba. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are json and javascript).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Chrome Extension Developer loads about 809 tokens when it runs. Until then it costs about 44 tokens; SKILL.md has 263 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~44

When it runs · the whole SKILL.md, loaded when a task matches

~809

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from davila7/claude-code-templates at commit 4c82aba, republished under its MIT licence (© davila7). 263 words, ~809 tokens.

name

chrome-extension-developer

description

Expert in building Chrome Extensions using Manifest V3. Covers background scripts, service workers, content scripts, and cross-context communication.

risk

safe

source

community

date_added

2026-02-27

{
  "manifest_version": 3,
  "name": "My Agentic Extension",
  "version": "1.0.0",
  "action": {
    "default_popup": "popup.html"
  },
  "background": {
    "service_worker": "background.js"
  },
  "content_scripts": [
    {
      "matches": ["https://*.example.com/*"],
      "js": ["content.js"]
    }
  ],
  "permissions": ["storage", "activeTab"]
}

// background.js (Service Worker)
chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
  if (message.type === "GREET_AGENT") {
    console.log("Received message from content script:", message.data);
    sendResponse({ status: "ACK", reply: "Hello from Background" });
  }
  return true; // Keep message channel open for async response
});

© davila7, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in cli-tool/components/skills/web-development/chrome-extension-developer of davila7/claude-code-templates.

Open the folder on GitHubat commit 4c82aba

Used in 3 other repositories

We found 12 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 3 other GitHub owners. This page covers the copy in davila7/claude-code-templates, which our catalogue first saw on October 7, 2026.

• sickn33/agentic-awesome-skillsskills/chrome-extension-developerplugins/agentic-awesome-skills/skills/chrome-extension-developer+1 more
• lingxling/awesome-skills-cnantigravity-awesome-skills/skills/chrome-extension-developerantigravity-awesome-skills/plugins/agentic-awesome-skills/skills/chrome-extension-developer+1 more
• henryalouf/ruflow.agents/skills/chrome-extension-developer.agents/skills/antigravity-awesome-skills/skills/chrome-extension-developer+4 more