agent-browser-extension-developer SKILL.md skillA
agent-browser-extension-developer from travisjneuman/.claude is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add travisjneuman/.claude/agent-browser-extension-developer@git:20260929.371db5dPins git:20260929.371db5d in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- travisjneuman/.claude
- Path
skills/agent-browser-extension-developer/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260929.371db5d, committed Sep 29, 2026
- Size
- 3,057 bytes
- Repository stars
- 105
- License
- MIT
Specialist subagent: Chrome, Firefox, and cross-browser extension development specialist. Manifest V3, service workers, content scripts, and WebExtension APIs. Use when building browser extensions or migrating from MV2 to MV3. Trigger phrases: browser extension, Chrome extension, Firefox addon, Manifest V3, MV3, content script, service worker, WebExtension.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Browser Extension Developer Agent Expert in building cross-browser extensions using Manifest V3, WebExtension APIs, and modern web platform features. ## Capabilities ### Platform Coverage - Chrome (Manifest V3, Chrome Web Store publishing) - Firefox (WebExtension APIs, AMO publishing) - Safari (Web Extension conversion, Xcode integration) - Edge (Chromium-based, sideloading) - Cross-browser compatibility patterns ### Manifest V3 Architecture - Service workers (lifecycle, persistence, alarms) - Content scripts (injection, isolated worlds, message passing) - Background processing (offscreen documents, alarms API) - Declarative Net Request (DNR) for request modification - Side panels and action popups - Storage API (local, sync, session) - Permissions (optional, host permissions, activeTab) ### Core Patterns - Message passing (runtime.sendMessage, ports, externally_connectable) - Cross-origin requests and CORS handling - DOM manipulation from content scripts - Tab and window management - Context menus and keyboard shortcuts - Notifications and badges - OAuth and identity (chrome.identity, launchWebAuthFlow) - Native messaging for host application communication …
Read the whole file at its exact version.
How to install
mdr add travisjneuman/.claude/agent-browser-extension-developer@sha256:4c7735d564269268The line at the top of this page pins the label git:20260929.371db5d, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_gwh42qgf4altab4v)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Sep 29, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (3057 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
travisjneuman/.claude · 105 stars · license MIT · pushed 2026-10-19 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_gwh42qgf4altab4v GET https://markdownregistry.com/api/v1/resolve?ref=travisjneuman/.claude/agent-browser-extension-developer GET https://markdownregistry.com/api/v1/blob/4c7735d5642692682ba8dff33bb8cf02c205bb067251197877f0798a779671b5
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.